JP7519622B2 - Hair Cutting Device - Google Patents

Description

The present disclosure relates generally to hair-cutting devices, and more particularly to hair-cutting devices that cut hair by applying light to the hair.

Patent document 1 describes a device configured to cut hair using laser light. The device described in patent document 1 includes a laser light source and a fiber optic. The laser light source is configured to generate laser light having a wavelength selected to target a predetermined chromophore to effectively cut the hair. The fiber optic has a proximal end, a distal end, an outer wall, and a cutting region disposed toward the distal end and extending along a portion of the side wall. The fiber optic receives laser light from the laser light source at the proximal end, directs the laser light from the proximal end toward the distal end, and emits light from the cutting region toward the hair when the cutting region contacts the hair.

Special table 2016-514491 publication

In the configuration described in Patent Document 1, improvements in usability are required in order to put a hair cutting device that uses light into practical use.

This disclosure has been made in light of the above-mentioned reasons, and aims to provide a hair cutting device with improved usability.

A hair cutting device according to an aspect of the present disclosure includes a light emitting module, a contact surface, a light receiving unit, a limiting unit, and a filter unit . The light emitting module has a light guide including a core portion, and cuts the hair by emitting light to the hair protruding from the skin. The contact surface is located around the light guide and contacts the skin. The light receiving unit receives light from the side of the contact surface that may include external light entering from the outside . The limiting unit stops the light output from the light emitting module according to the light intensity received by the light receiving unit. The filter unit reflects or absorbs light in a specific wavelength region emitted from the light emitting module, and transmits light other than the specific wavelength region.

The present disclosure has the advantage of providing a hair cutting device with improved usability.

FIG. 1 is a front view of a hair-cutting device according to an embodiment. FIG. 2 is a cross-sectional view of the hair-cutting device, showing a state in which the hair-cutting member is attached to the device body. FIG. 3 is a cross-sectional view of the hair-cutting device, showing a state in which the hair-cutting member is separated from the device main body. FIG. 4 is a rear view of the main part of the hair-cutting device, in particular showing the hair-cutting member and the receptacle part of the device main body. 5A and 5B are schematic cross-sectional and front views of the hair-cutting member of the hair-cutting device according to the embodiment of the present invention; Fig. 6A is a schematic cross-sectional view showing a configuration of a main part of the hair cutting device, and Fig. 6B is an enlarged view of the main part of Fig. 6A. 7A is a schematic cross-sectional view showing the operation of the hair-cutting device when cutting hair, particularly a scene before light is emitted to the hair, FIG. 7B is a schematic cross-sectional view showing the operation of the hair-cutting device when cutting hair, particularly a scene when light is emitted to the hair, and FIG. 7C is a schematic cross-sectional view showing the operation of the hair-cutting device when cutting hair, particularly a scene after the hair is cut. 8A and 8B are schematic cross-sectional views showing the operation of the hair-cutting device when cutting hair, particularly a scene before and after light is emitted to the hair, respectively. FIG. 9 is a block diagram showing a schematic configuration of a control circuit of the hair cutting device. 10A and 10B are graphs showing the light output and voltage change of the light receiving part in the hair cutting device in the contact and non-contact states with the skin, respectively. FIG. 11 is a flowchart showing a first operation example of the hair cutting device. FIG. 12 is a flowchart showing a second operation example of the hair cutting device. FIG. 13 is a schematic external view of a first modified example of the hair cutting device. FIG. 14 is a schematic front view of a second modified example of the hair cutting device. 15A to 15C are schematic cross-sectional views of a third modified example of the hair-cutting device.

(1) Overview Below, an overview of the hair-cutting device 1 according to this embodiment will be described with reference to Figures 1 to 5B. The hair-cutting device 1 is a device that cuts hair 91 (see Figure 6A) by applying light to the hair 91. The hair 91 to be cut by the hair-cutting device 1 is, for example, a person's "beard", but is not particularly limited thereto, and includes various hairs (for example, body hair on the arms or legs) that protrude from the skin 92 of a person or the like. In Figure 6A, the hair 91 and skin 92 are indicated by imaginary lines (two-dot chain lines).

In short, unlike typical "razors" or "scissors" that cut hair 91 with a physical "blade," the hair-cutting device 1 cuts hair 91 by applying light energy to the hair 91 instead of a "blade." Therefore, compared to typical "razors" or "scissors," the hair-cutting device 1 is less likely to damage the skin 92 around the hair 91, and is also less likely to experience physical deterioration such as chipped blades.

As shown in Figs. 1 to 3, the hair cutting device 1 according to this embodiment includes a hair-cutting member 3 and a device body 2. Here, as an example, the hair-cutting member 3 corresponds to the head of the hair-cutting device 1, and the device body 2 corresponds to the grip. As another example, the hair-cutting member 3 is detachably attached to the device body 2. However, in the hair-cutting device 1 of the present disclosure, it is not essential that the hair-cutting member 3 is detachable from the device body 2, and the hair-cutting member 3 and the device body 2 may be assembled integrally and not removable.

As shown in Figures 1, 5A, and 5B, the hair-cutting device 1 according to this embodiment includes a light-emitting module M1 and a sensor unit S1. As an example, the light-emitting module M1 and the sensor unit S1 are provided in the hair-cutting member 3, which is the head of the hair-cutting device 1.

As shown in FIG. 3, the light emitting module M1 has an optical waveguide 4 including a core portion 41. The light emitting module M1 cuts the hair 91 by emitting light to the hair 91 protruding from the skin 92.

The sensor unit S1 is a part for detecting the contact state of the skin 92 (see FIG. 5A). The sensor unit S1 may also be a part for detecting the proximity state of the skin 92.

When the hair-cutting member 3 is attached to the device body 2, light generated by the light source 21 (see FIG. 2) provided in the device body 2 is input to the tip surface (light-receiving surface 40A: see FIG. 2) of the optical waveguide 4, and the light is transmitted through the optical waveguide 4. In this embodiment, as an example, the light source 21 is a laser light source, and the light transmitted through the optical waveguide 4 is laser light.

In this embodiment, as described above, the hair-cutting device 1 is provided with the sensor unit S1, which makes it possible to realize control using the detection result regarding the contact state (or proximity state) of the skin 92 with the hair-cutting device 1, for example. Specifically, when the sensor unit S1 detects that the skin 92 has come into contact, it is possible to realize light output control such as starting the light output of the light source 21, and when it detects that the skin 92 has been removed, it is possible to realize light output control such as stopping or reducing the light output of the light source 21. As a result, there is an advantage in that it is possible to provide a hair-cutting device 1 with improved usability.

The hair-cutting method according to this embodiment also includes a light emission step and a detection step. In the light emission step, light is emitted from a light emission module M1 having an optical waveguide 4 including a core portion 41 to a hair 91 protruding from the skin 92, thereby cutting the hair 91. In the detection step, the proximity or contact state of the skin 92 to the sensor portion S1 is detected. Here, the hair-cutting method including the above-mentioned light emission step and detection step is used on a hair-cutting device 1.

Even in this configuration, the hair-cutting method includes a detection step, making it possible to realize control using the detection results regarding the contact state (or proximity state) of the skin 92. As a result, there is an advantage in that it is possible to provide a hair-cutting method with improved usability.

In this embodiment, the hair-cutting device 1 includes the light-emitting module M1 (described above), contact surfaces (the module-side contact surface 501 and the cover-side contact surface 301), and the light-receiving unit X1, as shown in Figures 5A and 5B. The contact surfaces are located around the optical waveguide 4 and come into contact with the skin 92. The "contact surface" here includes, for example, the surface around the opening 31 in the cover 30 of the hair-cutting member 3, and may also include the contact surface S10 of the sensor unit S1.

The light receiving unit X1 receives light from the side of the contact surface (501, 301). Here, as an example, the light receiving unit X1 is disposed in the storage space SP1 (see FIG. 5A) inside the cover 30, which is connected to the opening 31 and stores the light emitting module M1. "Light from the side of the contact surface" may include external light entering from outside the hair cutting device 1.

The opening 31 exposes at least a portion of the core portion 41 to the outside. When the opening 31 is provided in the cover 30 as in this embodiment, the "light from the contact surface side" may include external light that enters the storage space SP1 from outside the (virtual) opening surface 310 of the opening 31. Note that in the hair cutting device 1 disclosed herein, it is not essential that the opening 31 is provided in the cover 30.

In this embodiment, as described above, the hair-cutting device 1 is provided with the light-receiving unit X1, which makes it possible to realize control using the detection results regarding the light intensity from the contact surface (501, 301) side, for example. As a result, there is an advantage in that it is possible to provide a hair-cutting device 1 with improved usability.

The hair-cutting method according to this embodiment also includes a light emission step (described above) and an acquisition step. In the acquisition step, information about the light intensity from the side of the contact surface (501, 301) that is around the optical waveguide 4 and in contact with the skin 92 is acquired. Here, the hair-cutting method including the above-described light emission step and acquisition step is used on the hair-cutting device 1.

Even in this configuration, the hair-cutting method includes an acquisition step, making it possible to realize control using the detection results regarding the light intensity from the contact surface (501, 301). As a result, there is an advantage in that a hair-cutting method with improved usability can be provided.

(2) Details Hereinafter, the hair cutting device 1 according to this embodiment will be described in detail with reference to FIGS.

In the following, as an example, three mutually orthogonal axes, the X-axis, the Y-axis, and the Z-axis, are set, and in particular, the axis along the length of the optical waveguide 4 is the "X-axis," and the axis along the opposing direction when the opening 31 of the cover 30 of the hair-cutting member 3 faces the skin 92 is the "Y-axis." The X-axis, Y-axis, and Z-axis are all imaginary axes, and the arrows indicating "X," "Y," and "Z" in the drawings are merely indicated for the purpose of explanation and do not have any substance. Furthermore, these directions are not intended to limit the directions in which the hair-cutting device 1 is used. The direction of the optical axis C1 (see FIG. 2) of the optical waveguide 4 is along the X-axis.

(2.1) Definition The term "hair" in the present disclosure includes various hairs 91 protruding from the skin 92, that is, various hairs extending from the skin 92, and includes various body hairs such as human (human) hair, beard, eyebrows, leg hair, nose hair, and ear hair. Furthermore, for example, various hairs 91 protruding from the skin 92 of mammals such as dogs and cats, and other animals, are included in the term "hair" in the present disclosure. That is, the hair cutting device 1 according to the present embodiment is a device that targets these hairs 91. Furthermore, the term "skin" in the present disclosure also includes artificial skin and the like. In the present embodiment, as an example, a case will be described in which the hair 91 to be cut by the hair cutting device 1 is hair protruding from the skin 92 of a person, particularly the "beard" of an adult male. That is, the hair 91 to be cut by the hair cutting device 1 is hair growing from the skin 92 of a person's face. The skin 92 of a person, including the skin 92 of the face, is also called "skin".

In addition, the term "cutting" the hair 91 in this disclosure includes cutting the hair 91 in general, and includes, for example, cutting the hair 91 at the root (i.e., shaving), trimming the hair 91 to an appropriate length, and cutting only the tip. Therefore, the term "hair cutting device" in this disclosure includes, for example, a "shaver" or "hair cutting device" that is a device for shaving the hair 91, and a "trimmer," "hair clipper," or "scissors" that is a device for cutting the hair to an appropriate length. Furthermore, the term "cutting" the hair 91 in this disclosure includes not only cutting the hair 91 into two pieces at a substantially flat cutting surface, but also damaging the cut portion of the hair 91 to break the hair 91 at the cut portion. In this embodiment, as an example, a case will be described in which the hair cutting device 1 is a device (shaver) that is suitable for cutting the hair 91 (beard) to be cut at the root (i.e., shaving).

In addition, the term "laser light" in this disclosure refers to light generated by stimulated emission (Light Amplification by Stimulated Emission of Radiation). An example of a light source 21 that generates laser light is a semiconductor laser (LD: Laser Diode) that uses recombination light emission from a semiconductor. Compared to light generated by a light emitting diode (LED: Light Emitting Diode), laser light has the characteristics of high coherence, high output (power density), high monochromaticity (single wavelength), and high directionality.

In addition, in this disclosure, "optical waveguide" refers to an optical component that guides light along a desired path by passing the light through it. A specific example of an optical waveguide is an optical fiber having a core and a cladding with different refractive indices, with the core covered by the cladding. An optical fiber can guide light along a desired path by passing the light inside the core using the total reflection of the light at the interface between the core and the cladding. Here, optical waveguide is not limited to a transmission path that passes a communication signal (optical signal), but refers to any optical component that guides light along a desired path.

In addition, in this disclosure, "holding" means that one object supports another object so that the two objects maintain their relative positional relationship. Here, the relative positional relationship between the two objects may change slightly, and one object and the other object do not have to be firmly fixed. In other words, the holding member 5 may hold the optical waveguide 4 in a manner that causes the positional relationship between the optical waveguide 4 and the holding member 5 to change slightly.

In addition, the "refractive index" in this disclosure is the value obtained by dividing the speed of light in a vacuum by the speed of light in a medium (more precisely, the phase velocity). The refractive index is basically determined depending on the substance; for example, the refractive index of air is "1.0003" and the refractive index of water is "1.3334". Even for the same substance, the refractive index can differ depending on the wavelength of the incident light, but in this disclosure, unless otherwise specified, the refractive index will be shown for light with a wavelength of 404.7 nm (the h-line of mercury).

Furthermore, the term "power density" in this disclosure means the light intensity per unit area (1 ^cm2 ). The unit of power density is "kW/ ^cm2 " or "J/(s· ^cm2 )". Even if there is variation in the distribution of light intensity in the cross section of the optical waveguide 4, the average power density averaged over the entire cross section of the core portion 41 can be obtained by dividing the light intensity passing through the optical waveguide 4 by the cross-sectional area of the core portion 41 of the optical waveguide 4. In this disclosure, the average power density obtained in this manner is referred to as "power density" unless otherwise specified.

(2.2) Overall Configuration First, the overall configuration of the hair cutting device 1 according to this embodiment will be described with reference to FIGS. 1 to 3, 6A, and 6B.

As described above, the hair cutting device 1 comprises a hair cutting member 3 and a device body 2.

The hair-cutting member 3 includes a light-emitting module M1, a ferrule 71 as a connecting member, a holder portion H1, a sensor portion S1, a light-receiving portion X1, and a filter portion B1 (see FIG. 5A). A portion of each of the light-emitting module M1 and the ferrule 71 is inserted into the holder portion H1.

The hair-cutting member 3 further includes a fixing member F1, an adhesive member G1, a cover 30, and a fixing cap 34. The light-emitting module M1 includes a light guide 4 and a holding member 5. The holding member 5 holds the light guide 4 in a state in which a portion of a core portion 41 (described later) of the light guide 4 is exposed. The light-emitting module M1 further includes a fixing block 32.

The device body 2 includes a receptacle portion 81 to which the ferrule 71 of the hair cutting member 3 is mechanically connected (as a connection target portion), a light source 21, an optical system 22, and a case 20. The light source 21 generates light that is introduced into the core portion 41. The optical system 22 is disposed between the light source 21 and the receptacle portion 81. The case 20 houses the light source 21 and the optical system 22.

The optical waveguide 4 has a light emitting section 40 (see Figures 6A and 6B), and outputs light from the light emitting section 40 when light generated by the light source 21 is input. The hair cutting device 1 cuts the hair 91 by inputting the light generated by the light source 21 into the optical waveguide 4 and emitting the light from the light emitting section 40 of the optical waveguide 4 to the hair 91.

More specifically, the hair cutting device 1 employs a refractive index for the light emitting unit 40 that is close to the refractive index of the hair 91 to be cut. As a result, when the hair 91 is in contact with the light emitting unit 40, light leaks from the light emitting unit 40 to the hair 91, and the hair 91 is cut by the energy of this light. On the other hand, when the hair 91 is not in contact with the light emitting unit 40 and only air (refractive index: 1.0) is in contact with the light emitting unit 40, the difference in refractive index between the light emitting unit 40 and the air keeps the amount of light leaking from the light emitting unit 40 small.

In this embodiment, the hair-cutting member 3 corresponds to the head of the hair-cutting device 1, and the device body 2 corresponds to the grip. The case 20 of the device body 2 is formed, for example, in a prismatic shape having a length along the X-axis.

The hair-cutting member 3 is long. The hair-cutting member 3 has a length along the X-axis. The cover 30 of the hair-cutting member 3 houses the light-emitting module M1 therein, as shown in FIG. 5A. The cover 30 also has an opening 31. In other words, the hair-cutting device 1 includes a cover 30 configured to cover the light-emitting module M1 and having an opening 31 that exposes at least a portion of the core portion 41 to the outside.

As an example, the cover 30 is formed in the shape of a long, thin rectangular tube having a length along the X-axis. In this embodiment, the ferrule 71 of the hair-cutting member 3 is connected to the receptacle portion 81 of the case 20, so that the hair-cutting device 1 has an overall appearance that is roughly I-shaped when viewed from one side of the Z-axis.

In other words, the hair-cutting member 3 and the case 20 are both long. The hair-cutting device 1 has a stick-like shape when used. The stick-like shape is a shape in which the longitudinal direction of the hair-cutting member 3 and the longitudinal direction of the case 20 are aligned in one direction when the ferrule 71 is connected to the receptacle portion 81.

In this embodiment, as an example, both the case 20 and the cover 30 are made of synthetic resin.

In this way, the hair-cutting device 1, which has an overall appearance of a roughly I-shape, is used in the same way as a "straight-edged razor." That is, when cutting (here, "shaving") the hair 91 to be cut (here, "beard"), the user holds the hair-cutting device 1 by gripping the grip, i.e., the case 20, with one hand. In this state, the user brings the head of the hair-cutting device 1, i.e., one surface of the hair-cutting member 3 in the Y-axis direction, into contact with the user's skin 92, and moves the hair-cutting member 3 in the Z-axis direction along the skin 92, thereby cutting the hair 91 with the light emitting unit 40 of the hair-cutting member 3. At this time, the user cuts the hair 91 located in front of the traveling direction of the hair-cutting member 3 (head) (i.e., in the positive direction of the Z-axis) by bringing the surface of the hair-cutting member 3 facing the negative direction of the Y-axis into contact with the skin 92 and moving the hair-cutting member 3 in the positive direction of the Z-axis.

The hair-cutting device 1 may have another form in addition to the stick-like form (approximately I-shaped form) as a usage form. For example, the device body 2 may have a shaft portion that can rotate within a predetermined angle range near the receptacle portion 81, and the hair-cutting member 3 and the case 20 may be deformed from an approximately I-shaped form to an approximately L-shaped form. In this case, the user can change the usage form of the hair-cutting device 1 selectively between the stick-shaped form and the L-shaped form.

In addition to the receptacle section 81, the light source 21, the optical system 22, and the case 20, the device body 2 further includes a control circuit 6, a battery 23, a fan 24, a heat sink 25, and an operation section 26.

The control circuit 6, the optical system 22, the battery 23, the fan 24, and the heat sink 25 are all housed in the case 20. The operation unit 26 is provided on one surface of the case 20 (the surface facing the negative direction of the Y axis). The optical waveguide 4 included in the hair-cutting member 3 is arranged to face the optical system 22 in the case 20 by connecting one end of the optical waveguide 4 on the light receiving surface 40A (see FIG. 2) side together with the ferrule 71 to the receptacle portion 81.

The light source 21 generates light to be input to the optical waveguide 4 by converting electrical energy into optical energy. In this embodiment, the light source 21 is a laser light source. In other words, the light generated by the light source 21 is laser light generated by stimulated emission. Here, the light source 21 is a semiconductor laser that utilizes the recombination emission of a semiconductor.

The wavelength of the light generated by the light source 21 is 400 nm or more. In other words, the light source 21 generates laser light having a peak wavelength or dominant wavelength longer than 400 nm. In this embodiment, the wavelength of the light generated by the light source 21 is 700 nm or less. For example, light with a wavelength in the range of 400 nm or more and 450 nm or less can be expected to have a bactericidal effect on acne bacteria and the like present on the skin 92. Furthermore, light with a wavelength in the range of 450 nm or more and 700 nm or less can be expected to have an activating effect on the skin 92.

The control circuit 6 is a circuit that controls at least the light source 21. The control circuit 6 causes the light source 21 to emit light (light up) by supplying power to the light source 21. Furthermore, the control circuit 6 switches the light source 21 on and off, and adjusts the output (brightness or wavelength, etc.) of the light source 21. The control circuit 6 includes a printed wiring board (substrate) and multiple electronic components mounted on the printed wiring board. In addition to the light source 21, the control circuit 6 also controls the fan 24 and the operating unit 26. More details about the control circuit 6 will be explained in the section "(2.6) Control Circuit."

The optical system 22 is disposed between the light source 21 and the receptacle portion 81, and guides light from the light source 21 to the optical waveguide 4. The optical system 22 includes a plurality of lenses. In the example of FIG. 3, the optical system 22 includes a first lens 221, a second lens 222, a third lens 223, and a fourth lens 224. However, FIG. 3 does not strictly show the shape and arrangement of each lens, and merely shows the optical system 22 diagrammatically.

The battery 23 functions as a power source that supplies power for driving the control circuit 6, the light source 21, the fan 24, etc. In this embodiment, as an example, the battery 23 is a secondary battery such as a lithium ion battery (LIB) that can be charged and discharged.

The fan 24 is a cooling fan for cooling the light source 21. Specifically, the fan 24 generates an airflow that passes through the heat sink 25 inside the case 20, thereby promoting heat dissipation from the heat sink 25.

The heat sink 25 is made of a material with a relatively high thermal conductivity, such as aluminum. The heat sink 25 is thermally coupled to the light source 21 and mainly dissipates heat from the light source 21.

The operation unit 26 accepts a user operation and outputs an electrical signal corresponding to the user operation to the control circuit 6. In this embodiment, as an example, the operation unit 26 has at least one mechanical switch such as a push switch or a slide switch.

The opening 31 (see FIG. 1) is disposed on the surface of the cover 30 that comes into contact with the user's skin 92 (i.e., the surface facing the negative side of the Y-axis). The opening 31 is formed in a rectangular shape with a length along the X-axis. Through this opening 31, the space inside the cover 30 (storage space SP1: see FIG. 5A) is connected to the space outside.

A part of the optical waveguide 4, the holding member 5 and the fixed block 32 are housed in the cover 30. When the hair-cutting member 3 is attached to the device body 2, the light receiving surface 40A of the optical waveguide 4 faces closely to the fourth lens 224 of the optical system 22 in the case 20 of the device body 2. In short, when the hair-cutting member 3 is attached to the device body 2, the optical waveguide 4 is optically coupled to the light source 21 via the optical system 22. As a result, the light from the light source 21 is propagated through the optical waveguide 4 (core portion 41). In this embodiment, in addition to the core portion 41, the holding member 5 and the fixed block 32 are also exposed to the outside of the cover 30 through the opening 31.

The optical waveguide 4 is an optical member that guides the light generated by the light source 21 along a desired path by passing the light. In this embodiment, as an example, the optical waveguide 4 is an optical fiber. The optical waveguide 4 has a core portion 41 and a clad portion 42, and the clad portion 42 covers at least a portion (here, a portion) of the core portion 41. The core portion 41 is also arranged eccentrically on the outer periphery side of the clad portion 42. As an example, the core portion 41 is arranged on the outer periphery of the clad portion 42, and a portion of the core portion 41 is exposed from the outer periphery. Specifically, as shown in FIG. 6B, a portion of the region of the core portion 41 in the circumferential direction is arranged eccentrically so as to protrude outward from the outer periphery surface 420 of the clad portion 42.

The optical waveguide 4 is eccentrically disposed from one end face (light receiving surface 40A) in the X-axis direction to the other end face (termination surface 40B) such that a portion of the circumferential area of the core portion 41 protrudes outward beyond the outer peripheral surface 420 of the cladding portion 42.

The optical waveguide 4 may further have a protective sheath (a resin coating member) that protects the outer periphery of the clad portion 42. In other words, the optical fiber used as the optical waveguide 4 in this embodiment has a double structure of the core portion 41 and the clad portion 42, but may have a triple structure by adding a protective sheath located on the outside of the clad portion 42. However, it is preferable that the protective sheath is removed from at least the portion of the optical waveguide 4 exposed from the opening 31 so that the core portion 41 and the clad portion 42 are exposed.

The holding member 5 is a member that holds the optical waveguide 4. Here, the holding member 5 holds a portion of the optical waveguide 4 in the longitudinal direction by contacting it. Below, as shown in FIG. 3, the optical waveguide 4 will be described by dividing it into three regions (first region 401, second region 402, third region 403) along the X-axis direction.

The first region 401 of the optical waveguide 4 is a region that is held in contact with the holding member 5 as shown in FIG. 3. The light emitting section 40 is within the range of the first region 401.

The second region 402 and the third region 403 of the optical waveguide 4 are regions that extend from the holding member 5 in the negative direction of the X-axis. The third region 403 is a region that is bonded and fixed by the adhesive member G1 within the ferrule 71. The third region 403 is a region that is positioned by the ferrule 71.

The second region 402 is a region between the first region 401 and the third region 403, and is interposed between the holding member 5 and the ferrule 71. The second region 402 is a curved portion. The second region 402 is fixed by the fixing member F1 within the holder portion H1. That is, the optical waveguide 4 is arranged such that the first region 401 and the third region 403 are "shifted" in the Y-axis direction. Therefore, with respect to the optical axis of the core portion 41, the optical axis C1 (see FIG. 2) in the first region 401 and the optical axis in the third region 403 are non-coaxial with each other.

The holding member 5 is fixed to the fixed block 32. The holding member 5 is fixed to the fixed block 32 by an appropriate means such as adhesion, welding, pasting, or connection using a fastening member (screw, etc.). As a result, the optical waveguide 4 (first region 401) is indirectly fixed to the fixed block 32 via the holding member 5.

The fixed block 32 is fixed to the cover 30. The fixed block 32 is made of synthetic resin (or metal) and is formed in a rectangular column shape having a length along the X-axis. The fixed block 32 is fixed to the cover 30 by an appropriate means such as adhesion, welding, pasting, or connection using a fastening member (screw, etc.). As described above, the holding member 5 is fixed to the fixed block 32. Therefore, the optical waveguide 4 (first region 401) is indirectly fixed to the cover 30 via the holding member 5 and the fixed block 32.

Here, the light emitting portion 40 of the optical waveguide 4, the holding member 5, and the fixed block 32 of the hair-cutting member 3 are all exposed to the outside of the cover 30 through the opening 31. Specifically, the fixed block 32 is arranged along the length (X-axis) of the opening 31 in the cover 30. The holding member 5 is fixed to the surface of the fixed block 32 facing forward in the traveling direction of the hair-cutting device 1 (positive direction of the Z-axis). Moreover, the fixed block 32 and the holding member 5 are arranged toward the rear side of the traveling direction of the hair-cutting device 1 (i.e., the negative side of the Z-axis) in the short direction (Z-axis direction) of the opening 31 so as to secure a gap on the forward side of the traveling direction of the hair-cutting device 1 (hair-cutting member 3).

The fixed block 32 and the holding member 5 are arranged so that the surface facing the negative direction of the Y axis is flush with the surface of the cover 30 facing the negative direction of the Y axis. Furthermore, the optical waveguide 4 (light emitting section 40) is fixed to the surface of the holding member 5 facing forward in the direction of travel of the hair cutting device 1 (positive direction of the Z axis) as shown in FIG. 6A.

Although not shown in Figures 2 and 3, the hair cutting device 1 may further include components such as a charging circuit for the battery 23 or a display unit for displaying the operating status of the hair cutting device 1.

(2.3) Hair-Cutting Member (2.3.1) Configuration of Hair-Cutting Member Next, a more detailed configuration of the hair-cutting member 3 will be described with reference to Figs. 1 to 6B.

Figure 1 is a view (front view) of the hair-cutting device 1 as viewed from the negative side in the Y-axis direction to the positive direction. Figure 4 is a view (rear view) of the hair-cutting member 3 as viewed from the positive side in the Y-axis direction to the negative direction in a state where it has been separated from the receptacle portion 81 of the device body 2.

Figure 5A is a cross-sectional view (cross-sectional view of line A-A in Figure 5B) of the cover 30 housing the light emitting module M1 cut along the Y-Z plane at approximately the center in the longitudinal direction. Figure 5B is a view (front view) of the cover 30 housing the light emitting module M1 viewed from the negative side to the positive direction in the Y-axis direction. Figure 6A is a schematic cross-sectional view showing the configuration around the light guide 4 and holding member 5 in the hair-cutting member 3. Figure 6B is an enlarged view of the main part of Figure 6A.

In this embodiment, as described above, the hair-cutting member 3 includes a light-emitting module M1, a ferrule 71, a holder portion H1, a fixing member F1, an adhesive member G1, a cover 30, a fixing cap 34, a sensor portion S1, a light-receiving portion X1, and a filter portion B1.

The light emitting module M1 has a light guide 4, a holding member 5, and a fixed block 32. In particular, the light guide 4 is positioned so as to cut the hair 91 by emitting light to the hair 91 protruding from the skin 92.

(2.3.2) Optical Waveguide As described above, the optical waveguide 4 of the light emitting module M1 has the light emitting portion 40 that cuts the hairs 91 by emitting light to the hairs 91. In this embodiment, the optical waveguide 4 is an optical fiber having a core portion 41 and a cladding portion 42.

The cladding 42 covers the periphery of the core 41, except for a portion, from the light receiving surface 40A to the terminal surface 40B. Here, both the core 41 and the cladding 42 have relatively high optical transparency. However, the core 41 and the cladding 42 have different refractive indices, and the refractive index of the core 41 is greater than that of the cladding 42. With this configuration, the light incident on the core 41 from the light receiving surface 40A reaches the tip of the optical waveguide 4 (the end including the terminal surface 40B on the opposite side to the light receiving surface 40A) by passing only through the core 41 as much as possible due to total reflection or refraction at the interface between the core 41 and the cladding 42.

In the optical waveguide 4, for example, both the core portion 41 and the clad portion 42 are made of synthetic quartz. For example, the core portion 41 is made of synthetic quartz, and the clad portion 42 is made of synthetic quartz doped with impurities and has a different refractive index from that of the core portion 41. In this embodiment, as an example, when the fiber entrance NA (Numerical Aperture) is "0.1", the refractive index of the core portion 41 is "1.4698" and the refractive index of the clad portion 42 is "1.4309". When the fiber entrance NA is "0.2", the refractive index of the core portion 41 is "1.4698" and the refractive index of the clad portion 42 is "1.309". The NA and refractive index given here are merely examples and are not intended to specify the difference between the refractive index of the core portion 41 and the refractive index of the clad portion 42.

As shown in FIG. 3, the core portion 41 is disposed eccentrically on the outer periphery side of the clad portion 42. When viewed from the light receiving surface 40A, the core portion 41 and the clad portion 42 are each circular. However, when viewed from the light receiving surface 40A, the core portion 41 may be formed into a D-shape by cutting its outer periphery. The light receiving surface 40A is flush with the end face 710 of the ferrule 71.

In this embodiment, as an example, the diameter of the core portion 41 is approximately 10 μm, and the diameter of the cladding portion 42 is approximately 50 μm to 125 μm, but these values are not limited to these values.

The core portion 41 is disposed on the outer periphery of the cladding portion 42, and a portion of the core portion 41 is exposed from the outer periphery. Therefore, light passing through the optical waveguide 4 is more likely to leak to the outside through the exposed portion.

The portion of the optical waveguide 4 that is covered by the holding member 5 cannot leak light to the hairs 91, and therefore does not function as the light emitting portion 40 that emits light to the hairs 91. In this embodiment, the portion of the core portion 41 that is exposed and not covered by the cladding portion 42, and also not covered by the holder portion H1 and the ferrule 71, becomes the light emitting portion 40. Figures 6A and 6B show cross sections of the optical waveguide 4 including the light emitting portion 40 and the holding member 5 cut in the Y-Z plane.

The refractive index of the light emitting portion 40 is smaller than the refractive index of the surface 921 of the skin 92 (see FIG. 6A). Here, the human skin 92 (skin) includes the epidermis, dermis, subcutaneous tissue, etc. The surface 921 of the skin 92 here means the epidermis, which is the outermost of the multiple elements that make up the skin 92, or the surface of the epidermis.

That is, since the light emitting section 40 is composed of the core section 41 of the optical waveguide 4 (optical fiber) having the core section 41 and the cladding section 42, the refractive index of the core section 41 is set to be smaller than the refractive index of the surface 921 of the skin 92. As an example, assume that the refractive index of the surface 921 of human skin 92 is "1.4770". Then, if the refractive index of the core section 41, which is the light emitting section 40, is "1.4698" as described above, the condition that the refractive index of the light emitting section 40 is smaller than the refractive index of the surface 921 of the skin 92 is satisfied.

More specifically, in this embodiment, the refractive index of the light emitting section 40 is 1.47 or less. In short, the refractive index of the light emitting section 40 is set in the range of "1.4700" or less so that the refractive index of the light emitting section 40 is smaller than the refractive index of the surface 921 of the skin 92. As a result, even if there is some variation in the refractive index of the surface 921 of the skin 92, the refractive index of the light emitting section 40 is smaller than the refractive index of the surface 921 of the skin 92. In other words, even if the refractive index of the surface 921 of the skin 92 is slightly smaller than "1.4770", the condition that the refractive index of the light emitting section 40 is smaller than the refractive index of the surface 921 of the skin 92 can be satisfied.

Furthermore, the refractive index of the surface 921 of the skin 92 is smaller than that of the hair 91. In other words, when comparing the refractive indexes of the surface 921 of the skin 92, the hair 91 that is the cutting target protruding from the skin 92, and the light emitting unit 40 (core portion 41), the refractive index of the hair 91 is the largest, the refractive index of the surface 921 of the skin 92 is next largest, and the refractive index of the light emitting unit 40 is the smallest. As an example, assume that the refractive index of the human hair 91 (here, "beard") that is the cutting target of the hair cutting device 1 is "1.5432". Then, if the refractive index of the surface 921 of the human skin 92 is "1.4770", the condition that the refractive index of the surface 921 of the skin 92 is smaller than that of the hair 91 is satisfied.

In short, in this embodiment, the refractive index relationship is "light emitting portion < skin < hair", so that the refractive index of the surface 921 of the skin 92 is greater than that of the light emitting portion 40 (core portion 41), and the refractive index of the hair 91 is even greater than that of the surface 921 of the skin 92. In other words, the refractive index of the light emitting portion 40 is smaller than that of the hair 91 to be cut, and is also smaller than the refractive index of the surface 921 of the skin 92.

In this way, in the hair cutting device 1, the refractive index of the light emitting unit 40 is smaller than that of the hair 91 to be cut, so when the hair 91 is in contact with the light emitting unit 40, light leaks from the light emitting unit 40 to the hair 91. Therefore, the hair 91 is cut by the energy of the light leaking from the light emitting unit 40 to the hair 91. The principle (mechanism) by which the hair 91 is cut will be explained in detail in the section "(2.4) Usage Examples". On the other hand, when the hair 91 is not in contact with the light emitting unit 40 and only air (refractive index: 1.0) is in contact with the light emitting unit 40, the difference in refractive index between the light emitting unit 40 and the air keeps the amount of light leaking from the light emitting unit 40 small.

Furthermore, in terms of the relationship of the refractive index, it is more preferable that the difference between the refractive index of the light emitting unit 40 and the refractive index of the hair 91 to be cut is as small as possible. In other words, it is preferable that the refractive indexes of the surface 921 of the skin 92, the hair 91, and the light emitting unit 40 satisfy the magnitude relationship described above, while the difference is as small as possible. This makes the refractive index of the light emitting unit 40 close to the refractive index of the hair 91 to be cut, and when the hair 91 is in contact with the light emitting unit 40, light is more likely to leak from the light emitting unit 40 to the hair 91.

As an example, the refractive index of the light emitting portion 40 (core portion 41) is 1.4698, the refractive index of the surface 921 of the skin 92 is 1.4770, and the refractive index of the hair 91 is 1.5432, so that the refractive index of the light emitting portion 40 and the refractive index of the surface 921 of the skin 92 are approximately the same. Here, "approximately the same refractive index" means that, in the case where there are two mutually different refractive indices, the two have values close to each other such that the smaller refractive index is included within a range of ±5% of the larger refractive index. In this case, for example, if the angle of incidence of light (angle between the normal to the surface 921 of the skin 92) is 80 degrees (incident NA is about 0.17), the reflectance (s-polarized light) at the interface between an object having a refractive index that is -5% of the refractive index of the hair 91 and an object having the refractive index of the hair 91 is 13.2%, the reflectance (s-polarized light) at the interface between the light emitting unit 40 and the hair 91 is 12.5%, and the reflectance (s-polarized light) at the interface between the skin 92 and the hair 91 is 11.3%. Thus, even if the refractive index changes by -5%, the reflectance changes by only 2%. In other words, in this embodiment, the refractive index of the light emitting unit 40 (1.4698) and the refractive index of the surface 921 of the skin 92 are within a range of ±5% of the refractive index of the hair 91 (1.5432), so they can be said to be approximately the same.

As explained in the "(2.1) Definition" section, the refractive index of the same material varies depending on the wavelength, but the above-mentioned relationship of the refractive index is invariant at least within the range of the wavelength of the light output from the light source 21. In other words, at least within the range of the wavelength of the light output from the light source 21 (for example, the range of 400 nm to 700 nm), the refractive index satisfies the relationship of "light emitting part < skin < hair".

Furthermore, since the refractive index of the cladding portion 42 is smaller than that of the core portion 41, which is the light emitting portion 40, when the above-mentioned conditions are met, the refractive index of the cladding portion 42 is the smallest among the four: the core portion 41, the cladding portion 42, the surface 921 of the skin 92, and the hair 91. In other words, the relationship of the refractive indexes of the four is "cladding portion < core portion < skin < hair".

Incidentally, in the hair cutting device 1 according to this embodiment, the power density of the light passing through the optical waveguide 4 is 50 kW/ ^cm2 or more at least when cutting the hair 91. That is, in the optical waveguide 4 having the core portion 41 and the cladding portion 42, since the light passes through the inside of the core portion 41, the light intensity per unit area ( ¹ cm2) in the cross section of the core portion 41 is 50 kW or more. Here, the power density of the light passing through the optical waveguide 4 does not need to be always 50 kW/ ^cm2 or more, and it is sufficient that it is 50 kW/ ^cm2 or more at least when cutting the hair 91 (when cutting the hair 91).

In this embodiment, as an example, the power density of the light passing through the optical waveguide 4 when the hair 91 is cut is 50 kW/cm ² or more and 300 kW/cm ² or less. In addition, the power density of the light passing through the optical waveguide 4 when the hair 91 is cut is preferably 70 kW/cm ² or more, which is capable of cutting the hair 91, and more preferably 75 kW/cm ² or more. Furthermore, if the hair 91 can be cut quickly (for example, in about 0.1 s), the power density of the light passing through the optical waveguide 4 when the hair 91 is cut is more preferably 100 kW/cm ² or more. Furthermore, the power density of the light passing through the optical waveguide 4 when the hair 91 is cut is preferably 200 kW/cm ² or less, taking into consideration the optical output of the laser applicable as a consumer product, the fiber diameter, etc. In this embodiment, as an example, it is assumed that the initial value of the power density of the light passing through the optical waveguide 4 when the hair 91 is cut is 100 kW/cm ² .

Details will be explained in the sections "(2.4) Usage Examples" and "(3) Action", but with this level of power density, the hair cutting device 1 can easily and efficiently cut the hair 91 with the light emitted from the light emitting unit 40 to the hair 91.

Moreover, in this embodiment, the power density of the light passing through the optical waveguide 4 is variable. That is, in the hair cutting device 1 according to this embodiment, the power density of the light passing through the optical waveguide 4 is not fixed to an initial value, but is configured to be changeable. In particular, the power density of the light passing through the optical waveguide 4 when cutting the hair 91 is not fixed to an initial value (100 kW/cm ² ), but is changeable from the initial value. It is preferable that the power density of the light passing through the optical waveguide 4 when cutting the hair 91 is variable within a range of 50 kW/cm ² or more. The power density of the light passing through the optical waveguide 4 may change continuously or stepwise (discontinuously).

In this embodiment, the power density of the light passing through the optical waveguide 4 is adjusted by adjusting the output from the light source 21. The "adjustment" of the power density here includes both the mode of setting the power density to a specified value and the mode of changing the power density as described above. In short, when the power density of the light passing through the optical waveguide 4 is fixed to an initial value, the magnitude of the output from the light source 21 is determined so that the power density becomes the initial value (100 kW/cm ² ). On the other hand, when the power density of the light passing through the optical waveguide 4 is changed from the initial value to a desired value, the magnitude of the output from the light source 21 is determined so that the power density becomes the desired value after the change. The configuration for determining the magnitude of the output from the light source 21 will be described in detail in the section "(2.6) Control circuit".

(2.3.3) Holding Member Next, details of the holding member 5 of the light emitting module M1 will be described with reference to FIGS. 6A and 6B. FIG.

The holding member 5 is a portion that holds the optical waveguide 4. In particular, the holding member 5 holds the optical waveguide 4 in a form in which a portion of the core portion 41 of the optical waveguide 4 is exposed. In other words, the optical waveguide 4 is held in such a manner that a portion of the core portion 41 is shielded by the holding member 5 and light leakage is not hindered.

The optical waveguide 4 is held by the holding member 5 in such a manner that at least the light emitting portion 40 is exposed on the surface of the holding member 5 facing forward in the traveling direction of the hair cutting device 1 (positive direction of the Z axis). The core portion 41 of the optical waveguide 4 held in this manner functions as the light emitting portion 40, which cuts the hair 91 by emitting light to the hair 91.

Since the holding member 5 is fixed to the fixed block 32, the optical waveguide 4 (light emission section 40) is indirectly fixed to the cover 30 via the holding member 5 and the fixed block 32.

Here, the light emitting portion 40 of the light guide 4, the holding member 5, and the fixed block 32 are all exposed to the outside of the cover 30 through the opening 31. Moreover, in the opening 31, the fixed block 32 and the holding member 5 are arranged in a biased manner toward the rear side of the traveling direction of the hair cutting device 1 (i.e., the negative side of the Z axis) in the short direction (Z axis direction) of the opening 31 (see FIG. 5A). Therefore, as viewed from the holding member 5, a gap is secured between the periphery of the opening 31 and the front side of the traveling direction of the hair cutting device 1 (i.e., the positive side of the Z axis), and it is possible to take in the hair 91 to be cut into the opening 31 through this gap. In other words, the hair 91 to be cut can be introduced between the surface of the holding member 5 where the light guide 4 is held so that the light emitting portion 40 is exposed, that is, the surface facing forward in the traveling direction of the hair cutting device 1 (positive direction of the Z axis), and the periphery of the opening 31, as shown in FIG. 6A.

As shown in FIG. 6A, the hair 91 to be cut is introduced into the cover 30 through the opening 31 at a position opposite the light emitting portion 40 held by the holding member 5. In this state, the light guide 4 held by the holding member 5 is in a position where the light emitting portion 40 is butted against the hair 91 to be cut. This allows the light guide 4 to bring the light emitting portion 40 into contact with the hair 91 to be cut.

The holding member 5 has a base 51 and an adhesive member 52. The adhesive member 52 adheres the optical waveguide 4 to the base 51. The base 51 and the adhesive member 52 are both made of synthetic resin with optical transparency. In particular, the base 51 is a resin molded product formed using a mold. In contrast, the adhesive member 52 is a hardened product of a paste-like resin that is an adhesive. In other words, the adhesive member 52 is a hardened product of an adhesive for joining the base 51 and the optical waveguide 4.

The base 51 is formed in a rectangular column shape having a length along the X-axis. The base 51 is fixed to the surface of the fixed block 32 facing forward in the traveling direction of the hair cutting device 1 (positive direction of the Z-axis) by appropriate means such as adhesion, welding, pasting, or connection using a fastening member (screw, etc.). In this embodiment, the refractive index of the base 51 is equal to or greater than the refractive index of the core portion 41 (light emitting portion 40).

As shown in FIG. 6B, the base 51 has four surfaces, an opposing surface 511, a side surface 512, a rear surface 513, and a rear surface 514. A cross section perpendicular to the length (X-axis) of the base 51 is substantially rectangular with these four surfaces as its four sides. The opposing surface 511 is a surface that faces the surface 921 of the skin 92 when the hair 91 is cut. The side surface 512 is a surface that intersects with the surface 921 of the skin 92 when the hair 91 is cut, and is a surface adjacent to the opposing surface 511. The rear surface 513 is a surface facing the opposite side to the opposing surface 511 and is a surface adjacent to the side surface 512. The rear surface 514 is a surface facing the opposite side to the side surface 512 and is a surface adjacent to the rear surface 513. Here, the optical waveguide 4 is held by the side surface 512.

The adhesive member 52 adheres the optical waveguide 4 to the base 51. In this embodiment, the adhesive member 52 is provided on the side surface 512 of the base 51 so that the optical waveguide 4 is held on the side surface 512 of the base 51, and bonds the base 51 and the optical waveguide 4. Here, the adhesive member 52 is disposed over the entire length of the base 51 in the longitudinal direction (X-axis direction). Therefore, the optical waveguide 4 is adhered to the base 51 by the adhesive member 52 over the entire length of the base 51 in the longitudinal direction.

In this embodiment, the adhesive member 52 is in direct contact with the cladding portion 42 of the light emitting portion 40. Therefore, the adhesive member 52 is less subject to restrictions on its refractive index, and the material options are wider. In other words, if the refractive index of the light emitting portion 40 (core portion 41) is "1.4698", the refractive index of the adhesive member 52 may be greater than "1.4698". Between the light emitting portion 40 and the adhesive member 52, the cladding portion 42, which has a smaller refractive index than that of the light emitting portion 40, is interposed. Therefore, even if the refractive index of the adhesive member 52 is greater than that of the light emitting portion 40, the cladding portion 42 can appropriately limit the amount of light leakage, and the decrease in the power density of light due to the light leaking out of the core portion 41 more than necessary can be suppressed. Of course, the refractive index of the adhesive member 52 may be equal to or less than that of the light emitting portion 40.

The base 51 has a side surface 512 on which the optical waveguide 4 is held, and a positioning portion 53 (groove) for positioning the optical waveguide 4 is formed on the side surface 512. The positioning portion 53 is formed over the entire length of the base 51 in the longitudinal direction (X-axis direction). The optical waveguide 4 is held on the side surface 512 of the base 51 with the cladding portion 42 housed in the groove serving as the positioning portion 53.

The hair-cutting member 3 is located around the optical waveguide 4 and has contact surfaces (module-side contact surface 501 and cover-side contact surface 301: see FIG. 5A) that come into contact with the skin 92 when cutting the hair 91. The optical waveguide 4 is held by the holding member 5 so that the height L0 (see FIG. 6B) from the module-side contact surface 501 is 100 μm or less. Here, the module-side contact surface 501 corresponds to the opposing surface 511 of the base 51 and the surface of the fixed block 32 facing the negative direction of the Y axis. The cover-side contact surface 301 corresponds to the surface of the cover 30 facing the negative direction of the Y axis. In this embodiment, the height of the optical waveguide 4 from the cover-side contact surface 301 is approximately the same as the height from the module-side contact surface 501.

The height L0 of the optical waveguide 4 from such contact surface (501, 301) is equal to the height of the optical waveguide 4 from the surface 921 of the skin 92 when the hair 91 is cut. That is, in this embodiment, the height L0 is set to 100 μm or less, so that the distance (height) from the surface 921 of the skin 92 to the optical waveguide 4 when the hair 91 is cut is 100 μm or less. However, here, the height L0 is 1 μm or more and is not zero (0). Therefore, when the hair 91 is cut, the optical waveguide 4 can be separated from the surface 921 of the skin 92. Therefore, for example, even if there is a protuberance such as a pimple on the surface 921 of the skin 92, the optical waveguide 4 is unlikely to get caught by the protuberance.

(2.3.4) Cover and Fixing Cap As described above, the cover 30 is made of synthetic resin and is formed into a long rectangular column shape along the X-axis as a whole. The cover 30 is hollow and has an opening 31. The cover 30 houses the light emitting module M1 inside in a form in which the light emitting portion 40 of the optical waveguide 4 is exposed through the opening 31. Here, the cover 30 does not house the entire light emitting module M1, but houses a portion of the light emitting module M1 that protrudes in the positive direction of the X-axis beyond the holder portion H1. The fixing block 32 of the light emitting module M1 is fixed to the cover 30.

The cover 30 has an insertion port 300 (see FIG. 3) on one end surface in the negative direction of the X-axis. The light emitting module M1 is inserted through the insertion port 300 of the cover 30 and accommodated therein. The cover 30 also has a flange portion 320 on the periphery of the insertion port 300.

The fixed cap 34 is made of, for example, metal, but is not particularly limited and may be made of synthetic resin. The fixed cap 34 is cylindrical with an axis along the X-axis. One end face of the fixed cap 34 facing the negative direction of the X-axis is open, and the end face opposite to the one end face (the face facing the positive direction of the X-axis) has a hole portion 340 (see FIG. 1) through which the cover 30 can be inserted. The fixed cap 34 has a screw groove 341 on its inner peripheral surface into which the screw portion 810 (thread) of the receptacle portion 81 can be screwed.

The cover 30 is fixed to the holder part H1 via the flange part 320. Here, the fixing member F1 in the holder part H1 is adhered to the flange part 320, so that the cover 30 is fixed to the holder part H1 in a form in which the light emission module M1 is housed.

The fixed cap 34 is moved in the negative direction of the X-axis to cover the cover 30 so that the cover 30 passes through the hole 340, and is then positioned so as to cover almost the entire circumferential surface of the holder portion H1. The inner periphery of the hole 340 of the fixed cap 34 comes into contact with the flange portion 320 of the cover 30, restricting further movement in the negative direction of the X-axis. In the state shown in FIG. 3, the fixed cap 34 is rotatable with respect to the cover 30 and the holder portion H1.

In this embodiment, the fixing cap 34 has a restricting structure (here, a thread groove 341) that restricts the ferrule 71 from coming out of the receptacle portion 81. The thread portion 810 in the receptacle portion 81 of the device body 2 is screwed into the thread groove 341 of the fixing cap 34, thereby restricting the ferrule 71 from coming out of the receptacle portion 81. This makes it easier to prevent the ferrule 71 from coming out unintentionally. As a result, the entire hair cutting member 3 including the ferrule 71 is less likely to fall off from the device body 2.

(2.3.5) Ferrule The ferrule 71 is a connecting member that is integrally coupled to the light emitting module M1 in a form that holds the end portion on the light receiving surface 40A side of the optical waveguide 4, and that uniquely determines the position of the core portion 41 with respect to the light introduced into the optical waveguide 4. The ferrule 71 is mechanically connectable to the receptacle portion 81. By connecting the ferrule 71 to the receptacle portion 81, light is introduced into the core portion 41 from the receptacle portion 81 side.

The ferrule 71 is, for example, a cylindrical member that is long along the X-axis, and both end faces in the X-axis direction are open. The ferrule 71 is formed, for example, from a ceramic sintered body such as zirconia. The ferrule 71 is annular when viewed along the X-axis. The outer diameter of the ferrule 71 is, for example, 2.5 mm, but is not limited to this value.

The ferrule 71 is attached to the end of the optical waveguide 4 on the light receiving surface 40A side. The inner diameter of the ferrule 71 is larger than the outer diameter of the optical waveguide 4, and the ferrule 71 is integrally bonded to the light emitting module M1 via the adhesive member G1.

The adhesive member G1 bonds the optical waveguide 4 and the ferrule 71. The adhesive member G1 is a cured product of a paste-like resin that is an adhesive. In other words, the adhesive member G1 is a cured product of an adhesive for joining the inner circumferential surface of the ferrule 71 and the outer circumferential surface of the optical waveguide 4. The cladding portion 42 is arranged so that a part of its outer circumferential surface is in contact with the inner circumferential surface of the ferrule 71. The refractive index of the adhesive member G1 is smaller than the refractive index of the core portion 41. Therefore, it is easy to suppress the leakage of more light than necessary from the core portion 41 to the adhesive member G1.

Next, the receptacle portion 81 of the device body 2 to which the ferrule 71 is to be coupled will be described with reference to Figures 3 and 4. The receptacle portion 81 is, for example, a resin portion, and here is formed integrally with the case 20 of the device body 2. However, the receptacle portion 81 may also be a metal portion. The receptacle portion 81 may also be separate from the case 20, and may be fixed to the case 20 by any suitable means, such as adhesion, welding, pasting, or coupling using a fastening member (screw, etc.).

The receptacle portion 81 has a generally cylindrical shape. As shown in FIG. 3, the receptacle portion 81 is composed of a first portion 801 and a second portion 802. The first portion 801 is a portion that is continuous with one end of the case 20 on the positive side of the X-axis. The second portion 802 is a portion that has a smaller outer diameter than the first portion 801, and is a portion that is continuous with the end of the first portion 801 on the positive side of the X-axis.

The receptacle portion 81 has a circular through hole 811 that penetrates along its axial direction. The through hole 811 is connected to the storage space in the case 20 that houses the light source 21, the optical system 22, etc. However, the fourth lens 224 of the optical system 22 is positioned so as to cover the opening at the back of the through hole 811 in the receptacle portion 81. In other words, when the ferrule 71 is not connected to the receptacle portion 81, one surface of the fourth lens 224 of the optical system 22 is exposed to the outside through the through hole 811.

3, the through hole 811 includes a circular small diameter hole 812 and a circular large diameter hole 813 having an inner diameter larger than the inner diameter of the small diameter hole 812. The inner diameter of the small diameter hole 812 is set to be approximately the same as the outer diameter of the ferrule 71 so that the ferrule 71 fits into the small diameter hole 812 with almost no gap. The inner diameter of the large diameter hole 813 is set to be approximately the same as the outer diameter of the holder part H1 so that the holder part H1 fits into the large diameter hole 813. The inner diameter of the small diameter hole 812 is smaller than the outer diameter of the fourth lens 224 arranged adjacent to the small diameter hole 812.

When the ferrule 71 is connected to the receptacle portion 81, the holder portion H1 comes into contact with the peripheral portion 815 (see FIG. 3) of the opening of the small diameter hole 812. As a result, the ferrule 71 is prevented from penetrating further inside.

Here, with the holder part H1 in contact with the peripheral part 815 (see FIG. 3), the light receiving surface 40A of the optical waveguide 4 is arranged to face closely with a small gap to one surface of the fourth lens 224. In particular, the optical axis of the core part 41, whose position is uniquely determined by the ferrule 71, coincides with the optical axis CX1 (see FIG. 2) of the light source 21 and the optical system 22.

Here, the screw portion 810 (thread) (see FIG. 3) on the outer circumferential surface of the second portion 802 can be screwed into the screw groove 341 of the fixing cap 34.

The second part 802 also has a slit-shaped groove 814 in a region of its outer circumferential surface facing the positive Y-axis direction. The groove 814 penetrates the above-mentioned region of the second part 802. The groove 814 is connected to the large diameter hole 813. The groove 814 is formed across both ends of the second part 802 in the X-axis direction. The groove 814 is designed so that the protrusion H11 of the holder part H1 can be inserted into it. When the holder part H1 is in contact with the peripheral part 815 (see FIG. 3), the protrusion H11 is positioned so that it has penetrated all the way into the groove 814 in the X-axis direction.

(2.3.6) Holder Part The holder part H1 is a portion into which a part of the light emitting module M1 and a part of the ferrule 71 are inserted to integrally join them to each other.

The holder part H1 is, for example, a cylindrical member that is long along the X-axis, and both end faces in the X-axis direction are open. The holder part H1 is, for example, a part made of metal (or may be made of synthetic resin). The holder part H1 is annular when viewed along the X-axis.

The inner diameter of the holder part H1 is larger than the outer diameter of the light emitting module M1. The inner diameter of the holder part H1 is also larger than the outer diameter of the ferrule 71. The holder part H1 has a convex part H11 (see FIG. 4) on its outer circumferential surface that protrudes in the positive direction of the Y axis. The convex part H11 is inserted into the groove part 814 in the negative direction of the X axis, thereby uniquely determining the position of the hair-cutting member 3 in the direction around the axis of the hair-cutting member 3 relative to the receptacle part 81. Here, as an example, the convex part H11 is formed in a cylindrical shape, but the shape is not particularly limited.

In this embodiment, one end of the light emitting module M1 on the negative side of the X axis is fixed via the fixing member F1 in a state where it has entered the back of the opening on the positive side of the X axis in the holder part H1. Also, one end of the ferrule 71 on the positive side of the X axis is fixed via the fixing member F1 in a state where the end of the light guide 4 on the light receiving surface 40A side is attached to the ferrule 71 and has entered the back of the opening on the negative side of the X axis in the holder part H1. Here, the refractive index of the fixing member F1 is smaller than the refractive index of the core part 41. Therefore, it is easy to suppress the leakage of more light than necessary from the core part 41 to the fixing member F1.

The fixing member F1 is, for example, a cured product of a paste-like resin that is an adhesive. The fixing member F1 may be the same type of adhesive as the adhesive member G1 in the ferrule 71, or a different type of adhesive. The fixing member F1 bonds a part of the light emitting module M1 to a part of the ferrule 71. The fixing member F1 fixes the central axis of the light emitting module M1 and the central axis of the ferrule 71 in a curved state while aligning them with the central axis of the holder part H1. Note that it is desirable for the curvature of the second region 402 of the optical waveguide 4 to be as small as possible, thereby suppressing light leakage in the second region 402.

The multiple first connection lines 101 (see Figures 2 and 9) derived from the sensor unit S1 (S11, S12) and the light receiving unit X1 are arranged to pass through the inside of the holder unit H1. The multiple first connection lines 101 are held in the holder unit H1 via the fixing member F1, and the conductor portion 101A (see Figure 9: e.g., a connection pin) at the tip of each first connection line 101 is exposed from one end of the holder unit H1 on the negative side of the X-axis.

On the other hand, the receptacle portion 81 is embedded with a plurality of second connection lines 102 (see FIG. 2 and FIG. 9) electrically connected to the control circuit 6. The conductor portion 102A (see FIG. 9: for example, a pin receiving portion) at the tip of each second connection line 102 is exposed from one end (peripheral portion 815) on the positive side of the X-axis of the receptacle portion 81. When the convex portion H11 is inserted all the way into the groove portion 814 in the negative direction of the X-axis, the conductor portion 101A of each first connection line 101 exposed from the holder portion H1 is connected to the conductor portion 102A of the corresponding second connection line 102. In short, when the hair cutting member 3 is attached to the device body 2, not only is the optical waveguide 4 optically coupled to the light source 21 via the optical system 22, but the sensor portion S1 and the light receiving portion X1 are electrically connected to the control circuit 6 via the connection lines (101, 102).

(2.3.7) Sensor Unit Sensor unit S1 (see FIGS. 1, 5A, 5B, and 9) is a site for detecting the contact state of skin 92. Sensor unit S1 is disposed in the area surrounding optical waveguide 4.

The hair cutting device 1 of this embodiment has two sensor units S1. The two sensor units S1 are fixed to the cover 30. The two sensor units S1 are arranged on both sides of the optical waveguide 4 in a width direction W1 (see FIG. 5B) that intersects (here, as an example, is perpendicular to) the direction of the optical axis C1. The width direction W1 is parallel to the Z axis. The number of sensor units S1 is not particularly limited. The number of sensor units S1 may be one, or may be three or more.

In this embodiment, since the cover 30 has an opening 31, the two sensor units S1 are arranged in the Z-axis direction, sandwiching the opening 31 of the cover 30 between them, as shown in FIG. 1. In other words, one sensor unit S1 is arranged on the positive side of the Z-axis from the opening 31, which opens in a long rectangular shape along the X-axis, and the other sensor unit S1 is arranged on the negative side of the Z-axis from the opening 31. In other words, here, as an example, the sensor unit S1 is arranged around the opening 31.

Hereinafter, the sensor unit S1 on the positive side of the Z axis from the opening 31 may be referred to as the "first sensor unit S11," and the sensor unit S1 on the negative side of the Z axis from the opening 31 may be referred to as the "second sensor unit S12."

Each sensor unit S1 (detection unit) constitutes, for example, a capacitive touch sensor (touch switch). Each sensor unit S1 may be a capacitive proximity sensor that detects the proximity of an object by increasing its sensitivity. In this case, the sensor unit S1 may be a part for detecting the proximity state of the skin 92. Furthermore, each sensor unit S1 is not limited to a capacitive sensor, and may be an optical sensor, an inductive sensor, a magnetic sensor, or the like.

Each sensor unit S1 has a single electrode S2 (conductor portion) and is a self-capacitance sensor that detects a change in capacitance between the electrode S2 and the contact body (skin 92). Each sensor unit S1 also has, for example, a protective cover S3. Each protective cover S3 is arranged so as to cover the surface of the corresponding electrode S2 (one side on the negative side of the Y axis). Each protective cover S3 has electrical insulation properties. The protective cover S3 is formed, for example, from an electrically insulating resin material. Depending on the detection method of the sensor unit S1, the protective cover S3 may be omitted.

Each sensor unit S1 is elongated in one direction and is arranged so that its length direction is parallel to the direction of the optical axis C1 of the optical waveguide 4. Here, the first sensor unit S11 and the second sensor unit S12 are arranged along a pair of long sides of a rectangle that is elongated in the X-axis direction and forms the periphery of the opening 31.

Each sensor unit S1 is formed in a rectangular flat plate shape that is long along the direction of the optical axis C1. In this embodiment, as shown in FIG. 1, each sensor unit S1 has a length that is approximately the same as the length direction of the opening 31. One end of each sensor unit S1 on the positive side of the X axis is located at approximately the same position in the X axis direction as one end of the opening 31 on the positive side of the X axis, and the other end of each sensor unit S1 on the negative side of the X axis is located at approximately the same position in the X axis direction as the other end of the opening 31 on the negative side of the X axis. In short, the arrangement structure is such that contact with the skin 92 is highly likely to be detected regardless of which area of the opening 31 faces the skin 92 in the X axis direction.

Each sensor unit S1 is fixed so as to be embedded in the cover 30 by, for example, insert molding. The surface (contact surface S10) of each sensor unit S1 is generally exposed from the surface of the cover 30 (the surface on the negative side of the Y axis). The contact surface S10 corresponds to the surface of the protective cover S3 (the surface on the negative side of the Y axis). The contact surface S10 is generally flush with the surface of the cover 30. Here, as an example, the contact surface S10 and the surface of the cover 30 (the surface on the negative side of the Y axis) form the cover side contact surface 301.

Each electrode S2 is electrically connected to a line for the sensor unit S1 among the multiple first connection lines 101. When the hair-cutting member 3 is attached to the device body 2, each electrode S2 is electrically connected to the control circuit 6 via the connection lines (101, 102).

When the skin 92 comes into contact with the contact surface S10 of each sensor unit S1, an electrical signal including a change in the capacitance of a (pseudo) capacitor formed by the electrode S2 and the human body is output to the control circuit 6 via the connection lines (101, 102). The control circuit 6 (described below) determines whether the skin 92 has come into contact with the contact surface S10 or has been removed from the contact surface S10, depending on the electrical signal (detection signal) received from each sensor unit S1.

In this way, each sensor unit S1 can be said to have a contact surface S10 for detecting the contact state of the skin 92 without displacing its position relative to the light-emitting module M1 even when pressure is applied from the skin 92. The configuration of the sensor unit S1 described above is merely an example and can be modified as appropriate. For example, the sensor unit S1 may be configured as a movable switch in which a movable part having a contact surface for detecting the contact state of the skin 92 displaces relative to the light-emitting module M1 when pressure is applied from the skin 92.

However, as in this embodiment, the configuration of the sensor unit S1 that detects the contact state of the skin 92 without displacing its position relative to the light emitting module M1 tends to eliminate the need to secure a movable area compared to the case where a movable switch is used. As a result, it becomes easier to miniaturize the hair cutting device 1.

(2.3.8) Light receiving unit and filter unit The light receiving unit X1 is configured to receive light from the contact surface (the cover-side contact surface 301 and the module-side contact surface 501). The light receiving unit X1 has a light receiving element such as a photodiode as a semiconductor element. The light receiving unit X1 may have a photodiode array composed of a plurality of photodiodes.

The light receiving unit X1 also has a light receiving surface X10, which is, for example, a focusing lens. The light receiving surface X10 is arranged so as to face the contact surfaces (the cover side contact surface 301 and the module side contact surface 501). Here, as an example, the light receiving surface X10 faces the negative side of the Y axis.

The light receiving unit X1 in this embodiment is disposed inside the opening 31 in the cover 30. Specifically, the light receiving unit X1 is disposed within the storage space SP1 of the cover 30 that communicates with the opening 31, and is disposed on the positive side of the Y axis from the opening surface 310 (see FIG. 5A) of the opening 31. In particular, in this embodiment, the light receiving unit X1 is disposed on the top surface 302 (see FIG. 5A) inside the cover 30. The top surface 302 is a surface that faces the negative side of the Y axis and can face the skin 92.

Here, the light receiving surface X10 of the light receiving unit X1 faces the light emitting module M1 in the storage space SP1. That is, the light receiving surface X10 is disposed on the back side of the light emitting module M1 when viewed from the front of the opening 31. Specifically, in the vertical direction (direction of the Y axis) of the opening surface 310 of the opening 31, the first distance L1 is greater than the second distance L2 (see FIG. 5A). The first distance L1 is the distance from the opening surface 310 to the light receiving unit X1. The second distance L2 is the distance from the opening surface 310 to the optical waveguide 4. Here, the second distance L2 is approximately equal to the height L0 from the above-mentioned module side contact surface 501 to the optical waveguide 4 (see FIG. 6B).

In the example of FIG. 5B, the light receiving unit X1 is shown as being square-shaped when viewed from the front, but the shape of the light receiving unit X1 is not particularly limited. As shown in FIG. 5B, the light receiving unit X1 is disposed at approximately the center of the top surface 302 in the X-axis direction when viewed from the negative side of the Y-axis, but the position and size of the light receiving unit X1 are not particularly limited.

Although not shown in FIG. 5A, it is preferable that the light receiving unit X1 is mounted on a mounting board, and that the mounting board is fixed to the top surface 302 by an appropriate fixing means.

The light receiving element of the light receiving unit X1 is electrically connected to the line for the light receiving unit X1 among the multiple first connection lines 101. When the hair cutting member 3 is attached to the device body 2, the light receiving element of the light receiving unit X1 is electrically connected to the control circuit 6 via the connection lines (101, 102). The light receiving unit X1 outputs an electrical signal corresponding to the intensity of light incident from the light receiving surface X10 to the control circuit 6 via the connection lines (101, 102).

The filter unit B1 is configured to reflect or absorb light in a specific wavelength region emitted from the light emitting module M1, and transmit light outside the specific wavelength region. In other words, the filter unit B1 is an optical filter that cuts out unnecessary light in a specific wavelength region of the incident light by reflection or absorption, and transmits only the necessary light. The "unnecessary light" here refers to light in a specific wavelength region that is not desired to be incident on the light receiving surface X10 of the light receiving unit X1, and is light generated by the light source 21. As described above, the wavelength of the light generated by the light source 21 is, for example, 400 nm or more and 700 nm or less, so as an example, an optical filter is applied here in which the "specific wavelength region" overlaps at least a part of the region of 400 nm or more and 700 nm or less.

In this embodiment, the filter part B1 is arranged so as to cover the light receiving surface X10 of the light receiving part X1. The filter part B1 is, for example, a thin plate-like member. As an example here, the filter part B1 has approximately the same square shape as the light receiving part X1 when viewed from the front, and approximately the same dimensions as the light receiving part X1. The filter part B1 is layered on the light receiving surface X10 of the light receiving part X1.

When the skin 92 approaches and comes into contact with the cover-side contact surface 301 and the module-side contact surface 501, a part or almost all of the opening 31 is blocked by the skin 92, and as a result, the storage space SP1 is in a state where external light is difficult to enter. Therefore, the hair cutting device 1 of this embodiment uses the light receiving unit X1 to receive light (which may include external light) from the cover-side contact surface 301 and the module-side contact surface 501 and detects the light intensity. The hair cutting device 1 uses the detection result of the light intensity as one of the judgment materials for judging (estimating) the contact state of the skin 92 with the hair cutting device 1, and controls the light output of the light source 21. The "external light" here refers to light outside the hair cutting device 1, and includes, for example, sunlight outside the building, sunlight entering the building through a window, and lighting light.

Since the light emitting module M1 is housed in the housing space SP1, the light receiving unit X1 may receive light from the light emitting unit 40, specifically, light leaking from the light emitting unit 40 due to the light emitting unit 40 coming into contact with the hair 91 as described below. When detecting the intensity of external light, the light intensity from the light emitting unit 40 may become noise in the electrical signal output from the light receiving unit X1.

Therefore, as described above, by disposing the filter unit B1, the light receiving unit X1 is more likely to cut light in a specific wavelength region corresponding to the wavelength region of the light generated by the light source 21 (region of 400 nm or more and 700 nm or less). Therefore, although it is not essential to completely prevent the light generated by the light source 21 from entering the light receiving unit X1, the light received by the light receiving unit X1 is adjusted so that it predominantly contains external light. As a result, the reliability of the determination regarding the contact state of the skin 92 is improved.

In other words, by positioning the filter unit B1, even if the light receiving unit X1 is positioned at a position where it receives light emitted from the light emitting module M1, the light receiving accuracy of the light from the contact surface (301, 501) side is improved. In other words, the design freedom regarding the position of the light receiving unit X1 is improved. In particular, by positioning the filter unit B1 so as to cover the light receiving surface X10 of the light receiving unit X1, the light receiving accuracy of the light from the contact surface (301, 501) side is further improved.

(2.4) Example of Use Next, an example of use of the hair cutting device 1 according to this embodiment will be described with reference to FIGS. 7A to 8B.

That is, in this embodiment, the hair-cutting device 1 configured as described above is used to cut (here, "shave") hair 91 (here, "beard"). In this case, the user holds the device body 2 (grip) of the hair-cutting device 1 in one hand to hold the hair-cutting device 1, and brings the hair-cutting member 3 (head), i.e., the surface of the cover 30 facing the negative direction of the Y axis, into contact with the user's skin 92. As a result, as shown in FIG. 7A, the hair 91 to be cut is introduced into the cover 30 from the opening 31 to a position facing the light emitter 40 held by the holding member 5.

As shown in FIG. 7A, when the light emitting unit 40 is not in contact with the hair 91, the light emitting unit 40 is in contact with air, and the difference in refractive index between the light emitting unit 40 and air causes almost no leakage of light from the light emitting unit 40. In this state, the user moves the hair-cutting member 3, which serves as the hair-cutting device 1, along the surface 921 of the skin 92 in the direction of the arrow A1 in FIG. 7A.

As the hair-cutting member 3 moves, as shown in FIG. 7B, the light emitting unit 40 comes into contact with a hair 91 located in front of the direction of travel of the hair-cutting member 3 (i.e., in the positive direction of the Z-axis). At this time, due to the difference in refractive index between the light emitting unit 40 and the hair 91, light from the light emitting unit 40 is emitted to the hair 91 so that it leaks out to the hair 91. In other words, since the refractive index of the light emitting unit 40 is smaller than the refractive index of the hair 91 to be cut, when the hair 91 comes into contact with the light emitting unit 40, light leaks out from the light emitting unit 40 to the hair 91, and light is emitted from the light emitting unit 40 to the hair 91.

Furthermore, in the state shown in FIG. 7B, a portion of the light emitted from the light emitting unit 40 to the hair 91 is scattered, so that the light from the light emitting unit 40 is also emitted to the skin 92 around the hair 91. Specifically, a portion of the light leaking from the contact site of the light emitting unit 40 with the hair 91 is scattered by the hair 91 and emitted to the skin 92. Here, as shown in FIG. 7B, the light emitted mainly to the hair 91 is referred to as the first emitted light Op1, and the light emitted mainly to the skin 92 is referred to as the second emitted light Op2. In other words, when the hair 91 is in contact with the light emitting unit 40, the light emitting unit 40 emits the first emitted light Op1 to the hair 91 and the second emitted light Op2 to the skin 92.

In particular, when the first emitted light Op1 is emitted from the light emitting unit 40 to the hair 91, the hair 91 is cut by the energy of the light (first emitted light Op1) emitted from the light emitting unit 40 to the hair 91. In short, in this embodiment, the wavelength of the light (e.g., 400 nm or more and 700 nm or less) output from the light source 21 and passing through the optical waveguide 4 includes the wavelength of light absorbed by the chromophore (a part of a molecule that gives the molecule its color) in the hair 91. Therefore, the first emitted light Op1 is converted into heat by being absorbed by the chromophore of the hair 91, and this heat breaks the molecular bonds of the hair 91, or melts or burns the hair 91. Chromophores that can be targets of the light (first emitted light Op1) emitted from the light emitting unit 40 to the hair 91 include, for example, keratin, water, and other chromophores.

As described above, the user can cut the hair 91 protruding from the skin 92 by moving the hair-cutting member 3 as the hair-cutting device 1 along the skin 92 in the direction of the arrow A1 (see FIG. 7A). Therefore, after the optical waveguide 4 has passed, only the root portion of the hair 91 that remains uncut remains on the skin 92, as shown in FIG. 7C.

However, in the hair cutting device 1, as shown in FIG. 7B, even if the light emitting unit 40 does not come into contact with the hair 91, light may be emitted to the hair 91, for example, due to light (evanescent waves) seeping into the air from the interface between the light emitting unit 40 and the air. Therefore, not only when the light emitting unit 40 comes into contact with the hair 91, but also when the light emitting unit 40 and the hair 91 come close enough to come into contact with each other, the first emitted light Op1 may be emitted from the light emitting unit 40 to the hair 91 in the hair cutting device 1, and the hair 91 may be cut.

Depending on the condition of the skin 92, as shown in Figures 8A and 8B, when the hair-cutting device 1 is used to cut (here, "shave") the hair 91 (here, "beard"), the light emitting unit 40 may come into contact with a part of the skin 92. Figures 8A and 8B show an example of use of the hair-cutting device 1 when a protuberance 922, such as a pimple, is present around the hair 91 (around the hair root) on the skin 92. The protuberance 922 is a part of the skin 92 that is raised (protruding) compared to the surface 921 of the skin 92 around the protuberance 922.

That is, as shown in FIG. 8A, when the light emitting unit 40 is not in contact with the hair 91, the light emitting unit 40 is in contact with air, and the difference in refractive index between the light emitting unit 40 and air causes almost no leakage of light from the light emitting unit 40. In this state, the user moves the hair-cutting member 3 along the surface 921 of the skin 92 in the direction of the arrow A1 in FIG. 8A.

As the hair-cutting member 3 moves, as shown in FIG. 8B, the light emitting unit 40 comes into contact with a hair 91 located in front of the traveling direction of the hair-cutting member 3 (i.e., in the positive direction of the Z-axis). At this time, due to the difference in refractive index between the light emitting unit 40 and the hair 91, light from the light emitting unit 40 (first emitted light Op1) is emitted to the hair 91 so that it leaks out to the hair 91. When the first emitted light Op1 is emitted from the light emitting unit 40 to the hair 91, the hair 91 is cut by the energy of the light (first emitted light Op1) emitted from the light emitting unit 40 to the hair 91.

8B, the light emitting unit 40 also comes into contact with the protuberance 922 around the hair 91 on the skin 92. At this time, due to the difference in refractive index between the light emitting unit 40 and the surface 921 (protuberance 922) of the skin 92, the light from the light emitting unit 40 is emitted to the skin 92 so as to leak out to the skin 92. That is, since the refractive index of the light emitting unit 40 is smaller than the refractive index of the surface 921 of the skin 92, when the skin 92 is in contact with the light emitting unit 40, light leaks out from the light emitting unit 40 to the skin 92, and light (second emitted light Op2) is emitted from the light emitting unit 40 to the skin 92. At this time, the second emitted light Op2 is directly emitted from the light emitting unit 40 to the skin 92, and the second emitted light Op2 is mainly emitted to the protuberance 922. In particular, in this embodiment, the portion of the optical waveguide 4 that is in direct contact with the raised portion 922 is likely to be the cladding portion 42, and the energy of the second emitted light Op2 is lower than that of the first emitted light Op1.

(2.5) Replacement of Hair-Cutting Member In the present embodiment, the ferrule 71 is detachable from the receptacle portion 81, so that the hair-cutting member 3 can be easily replaced (exchanged). The replacement operation of the hair-cutting member 3 will be described below.

The hair-cutting member 3 may need to be replaced due to deterioration over time. Specifically, the light emitting portion 40 of the optical waveguide 4 may be damaged by repeated contact with the skin 92, hair 91, etc., reducing the amount of light emitted, which may result in a situation where the hair 91 cannot be completely cut.

First, the user removes the old hair-cutting member 3 from the device body 2. Specifically, the user rotates the fixing cap 34 of the hair-cutting member 3 with his/her fingers in a direction to loosen it. As a result, the screw groove 341 fastened to the screw portion 810 of the receptacle portion 81 loosens, and the fixing cap 34 moves in the positive direction of the X-axis, and finally comes out of the receptacle portion 81. In this state, the user can pull the ferrule 71 and the light-emitting module M1, which is integrally connected to the ferrule 71 via the holder portion H1, in the positive direction of the X-axis by holding the outside of the cover 30 with his/her hand and pulling it in the positive direction of the X-axis. At that time, the protrusion H11 that was fitted in the groove portion 814 also moves in the positive direction of the X-axis along the groove portion 814, and finally comes out of the groove portion 814 (see FIG. 3).

Then, the user attaches, for example, a new hair-cutting member 3 to the device body 2. Specifically, while holding the outside of the cover 30 with his/her hand, the user pushes it in the negative direction of the X-axis so that the ferrule 71 at the tip side is inserted into the receptacle portion 81. At that time, the user adjusts the circumferential orientation of the hair-cutting member 3 while using the convex portion H11 of the holder portion H1 as a guide. In other words, the user adjusts the circumferential orientation of the hair-cutting member 3 so that the convex portion H11 faces the groove portion 814 in the X-axis direction. Then, the user pushes the cover 30 in the negative direction of the X-axis so that the convex portion H11 is inserted toward the groove portion 814.

As a result, the ferrule 71 fits into the small diameter hole 812 in the receptacle portion 81, and the holder portion H1 fits into the large diameter hole 813 in the receptacle portion 81. At this point, circumferential rotation of the hair cutting member 3 relative to the device body 2 is restricted. The light receiving surface 40A then faces closely the optical system 22 (fourth lens 224), and further the optical axis C1 of the core portion 41 coincides with the optical axis CX1 of the optical system 22 (automatically, without the user being aware of it). In short, positioning of the light emitting module M1 is facilitated, improving assembly.

Finally, the user can attach the fixing cap 34 to the receptacle portion 81 to prevent the hair-cutting member 3 from coming out of the device body 2. The fixing cap 34 of the hair-cutting member 3 may be reused or replaced with a new one.

In this way, the hair-cutting member 3 is removably attached to the receptacle portion 81 of the device body 2, which results in improved assembly and easier optical adjustment.

In the above example, the replacement work was assumed to be performed by the user, but this improvement in ease of assembly does not only affect the replacement work performed by the user, but can also affect, for example, the assembly work performed by the worker during the manufacture of the hair cutting device 1.

(2.6) Control Circuit Next, the configuration of the control circuit 6 will be described with reference to FIGS.

As shown in FIG. 9, the control circuit 6 is electrically connected to the light source 21, the battery 23, the fan 24, the operation unit 26, etc. In addition, when the hair-cutting member 3 is attached to the device body 2, the control circuit 6 is electrically connected to each of the light receiving unit X1, the first sensor unit S11, and the second sensor unit S12 via a plurality of connection lines (101, 102).

The control circuit 6 has an input unit 61, a mode switching unit 62, an output adjustment unit 63, a drive unit 64, and a judgment unit 65.

The control circuit 6 includes, for example, a microcontroller having one or more processors and one or more memories. The microcontroller realizes the function of the control circuit 6 by executing a program recorded in one or more memories with one or more processors. The program may be recorded in the memory in advance, or may be provided recorded on a non-transitory recording medium such as a memory card, or provided through a telecommunications line. In other words, the program is a program for causing one or more processors to function as the control circuit 6.

An electrical signal corresponding to a user's operation is input to the input unit 61 from the operation unit 26. For example, when the operation unit 26 receives an operation such as switching the main power supply on/off or switching the operating mode, an electrical signal corresponding to the operation is input to the input unit 61.

The mode switching unit 62 switches the operation mode of the light source 21. In this embodiment, the light source 21 has two operation modes, a first mode and a second mode, which will be described later. The mode switching unit 62 switches between the first mode and the second mode, for example, in accordance with an electrical signal from the input unit 61.

The driving unit 64 drives the light source 21 by supplying power to the light source 21. That is, the driving unit 64 causes the light source 21 to emit light (turn on) by supplying a driving current I1 to the light source 21 consisting of a semiconductor laser. Here, when driving the light source 21, the driving unit 64 causes the light source 21 to emit light by supplying a rectangular wave-shaped driving current I1 that alternates between a light-emitting period T1 and an off period T2 to the light source 21 as shown in FIG. 9. That is, the driving unit 64 supplies the driving current I1 consisting of a pulse current to the light source 21, and in response to this, the light source 21 intermittently emits light (blinks).

That is, the light source 21 emits light during the light-emitting period T1 of the drive current I1, and the light source 21 is turned off during the off period T2 of the drive current I1, so that the light source 21 generates light intermittently (blinks) in accordance with the frequency of the drive current I1. In short, the light source 21 generates light intermittently by repeating the light-emitting period T1 and the off period T2. In this embodiment, as an example, it is assumed that the duty of the drive current I1 (the proportion of the light-emitting period T1 in one cycle) is 50%. In other words, the duration of the light-emitting period T1 is equal to the duration of the off period T2.

In this embodiment, the light source 21 has two operating modes: a first mode and a second mode.

The first mode is a mode that prioritizes the effect on the skin 92, and is a mode in which the time length of the light emission period T1 is 1/10,000 of a second or less. In other words, when the operation mode of the light source 21 is the first mode, the time length of the light emission period T1 of the light source 21 is 1/10,000 of a second or less. In other words, in the first mode, the drive unit 64 drives the light source 21 with a drive current I1 having a frequency of 5 kHz or more. As a result, the maximum time for which the light source 21 continuously generates light is 1/10,000 of a second (1/10,000 s) or less. In this embodiment, as an example, when the operation mode of the light source 21 is the first mode, the time length of the light emission period T1 of the light source 21 is 1/15,000 of a second.

The second mode is a mode that prioritizes cutting of the hair 91, and is a mode in which the duration of the light emission period T1 is 1/100 of a second or more. In other words, when the operation mode of the light source 21 is the second mode, the duration of the light emission period T1 of the light source 21 is 1/100 of a second or more. In other words, in the second mode, the drive unit 64 drives the light source 21 with a drive current I1 having a frequency of 50 Hz or less. As a result, the minimum time for which the light source 21 continuously emits light is 1/100 of a second (1/100 s) or more. As an example, in this embodiment, when the operation mode of the light source 21 is the second mode, the duration of the light emission period T1 of the light source 21 is 1/80 of a second.

Here, the control circuit 6 has a mode switching unit 62 that switches between the first mode and the second mode. That is, in this embodiment, the operation mode of the light source 21 can be switched between a first mode in which the time length of the light emission period T1 is 1/10,000th of a second or less, and a second mode in which the time length of the light emission period T1 is 1/100th of a second or more.

The output adjustment unit 63 adjusts the output of the light source 21 by controlling the drive unit 64. The output of the light source 21 that is the subject of adjustment by the output adjustment unit 63 includes the light intensity (brightness) and wavelength of light generated by the light source 21. The output adjustment unit 63 adjusts the output of the light source 21 according to, for example, an electrical signal from the input unit 61.

In particular, in this embodiment, as described above, the power density of the light passing through the optical waveguide 4 is adjusted by the output from the light source 21. Therefore, the output adjustment unit 63 adjusts the power density of the light passing through the optical waveguide 4 by adjusting the magnitude (power density) of the output of the light source 21. Specifically, the output adjustment unit 63 adjusts the power density of the light output from the light source 21 to the optical waveguide 4 by changing the magnitude of the drive current I1 supplied from the drive unit 64 to the light source 21.

Furthermore, as described above, when the power density of the light passing through the optical waveguide 4 is variable, the change in power density is realized by the output adjustment unit 63. That is, the output adjustment unit 63 changes the power density of the light passing through the optical waveguide 4 by changing the magnitude of the output (power density) of the light source 21. The output adjustment unit 63 changes the magnitude of the output (power density) of these light sources 21 according to, for example, an electrical signal from the input unit 61.

In addition, the output adjustment unit 63 may adjust the output of the light source 21 under control of the restriction unit 11, which will be described later.

Next, we will explain the process of determining the contact state of the skin 92 in the control circuit 6.

The determination unit 65 of the control circuit 6 determines the contact state of the skin 92 with respect to the contact surfaces (the module-side contact surface 501 and the cover-side contact surface 301) (executes a determination process). Specifically, the determination unit 65 determines (estimates) that the skin 92 has switched from a non-touch state to a contact state, and that the skin 92 has switched from a contact state to a non-touch state.

In this embodiment, the determination unit 65 determines the contact state based on the electrical signals received from the sensor unit S1 (first sensor unit S11, second sensor unit S12) and the light receiving unit X1. Then, based on the determination result, the determination unit 65 controls the drive unit 64 (or the output adjustment unit 63) to start driving the light source 21 to perform light output, or to stop driving the light source 21 (or to reduce the light output).

The determination unit 65 starts executing the determination process, for example, when it receives an operation to switch the main power supply from OFF to ON through the operation unit 26. In other words, as an example in this embodiment, when the main power supply is turned ON through the operation unit 26, the control circuit 6 goes into a standby state in which it can start driving the light source 21. Therefore, even if the main power supply is switched ON, the drive unit 64 does not immediately start driving the light source 21.

In this embodiment, as an example, the determination unit 65 determines the contact state based on the electrical signals (detection signals) of both the sensor unit S1 and the light receiving unit X1. However, in this disclosure, the sensor unit S1 is not an essential component, and if the sensor unit S1 is omitted, the determination unit 65 may determine the contact state based only on the electrical signal of the light receiving unit X1.

The determination unit 65 includes a restriction unit 11 and an execution unit 12 (see FIG. 9). When the determination unit 65 determines that the skin 92 has switched from a non-contact state to a contact state based on the detection signal, the execution unit 12 executes light output from the light emission module M1. In other words, the execution unit 12 causes the drive unit 64 to start driving the light source 21.

When the determination unit 65 determines based on the detection signal that the skin 92 has switched from a contact state to a non-contact state, the limiting unit 11 limits the light output from the light emission module M1. In other words, the limiting unit 11 causes the driving unit 64 to stop driving the light source 21 (or may reduce the light output).

[Light output start]
The determination unit 65 determines whether the first condition is satisfied based on the detection signal received from the sensor unit S1. When an object at ground potential, such as a human body, contacts (touches) the sensor unit S1, a pseudo capacitor is formed by the electrode S2 and the human body. As a result, the contact of the human skin 92 appears as a change in the capacitance of each sensor unit S1 (capacitor). The determination unit 65 monitors, for example, a change in voltage corresponding to the change in capacitance through the received detection signal. In other words, the determination unit 65 detects the contact state of the skin 92 with the sensor unit S1 (detection step). The determination unit 65 determines that the first condition is satisfied when both the voltage level of the first sensor unit S11 and the voltage level of the second sensor unit S12 exceed the first threshold. The determination unit 65 may determine that the first condition is satisfied when only one of the voltage level of the first sensor unit S11 and the voltage level of the second sensor unit S12 exceeds the first threshold.

The determination unit 65 also determines whether the second condition is satisfied based on the detection signal received from the light receiving unit X1. As described above, when the skin 92 approaches and comes into contact with the cover side contact surface 301 and the module side contact surface 501, a part or almost all of the opening 31 is blocked by the skin 92. Therefore, it becomes difficult for external light to enter the storage space SP1, and the light intensity received by the light receiving unit X1 decreases compared to when the skin 92 is in a non-contact state. Since a current proportional to the light intensity flows through the photodiode, the determination unit 65 receives a detection signal from the light receiving unit X1 in which the current flowing through the photodiode is converted into a voltage. In other words, the determination unit 65 monitors, for example, a change in voltage through the received detection signal. In other words, the determination unit 65 acquires information regarding the light intensity from the light receiving unit X1 (acquisition step). The current-voltage conversion may be performed by the control circuit 6.

The determination unit 65 determines that the second condition is satisfied when the light intensity received by the light receiving unit X1 is less than a first predetermined value, that is, when the signal level (e.g., voltage) of the detection signal received from the light receiving unit X1 is less than the reference value Rf1 (see FIG. 10B). In FIG. 10B, the voltage value V1 is the voltage value when the opening 31 is almost completely blocked by the skin 92 (in contact). The voltage value V2 is the voltage value when the opening 31 is almost open (in non-contact). The reference value Rf1 is set, for example, between the voltage value V1 and the voltage value V2. The example in FIG. 10B shows a schematic change in the signal level (voltage) of the detection signal received from the light receiving unit X1 when the contact state changes to the non-contact state at time t3.

The determination unit 65 determines that the skin 92 has switched from a non-contact state to a contact state when both the first condition and the second condition are satisfied. When the sensor unit S1 is omitted, the determination unit 65 may determine that the skin 92 has switched from a non-contact state to a contact state when only the second condition is satisfied.

When the determination result of the determination unit 65 indicates a switch to a contact state, the execution unit 12 causes the drive unit 64 to start driving the light source 21. In other words, when the proximity or contact (here, contact) of the skin 92 with the sensor unit S1 is detected (when the first condition is satisfied), the execution unit 12 executes light output from the light emission module M1. The execution unit 12 causes the drive unit 64 to start supplying power to the light source 21. Therefore, for example, when the user touches the skin 92 with the sensor unit S1, light output is more likely to be executed automatically, and usability can be improved.

In particular, in this embodiment, as described above, in addition to the first condition, the execution unit 12 executes light output from the light emission module M1 when the light intensity received by the light receiving unit X1 falls below a predetermined value (first predetermined value) (when the second condition is satisfied). Therefore, usability can be further improved while improving the reliability of detection of the skin 92.

[Optical output limit]
The determination unit 65 determines whether the third condition is satisfied based on the detection signal received from the sensor unit S1. The determination unit 65 determines that the third condition is satisfied when both the voltage level of the first sensor unit S11 and the voltage level of the second sensor unit S12 are less than the second threshold. Here, as an example, the second threshold is equal to the first threshold. The determination unit 65 may determine that the third condition is satisfied when only one of the voltage levels of the first sensor unit S11 and the second sensor unit S12 is less than the second threshold. In particular, for example, in [Start of light output], the first condition may be determined to be satisfied when both voltage levels of the two sensor units S1 exceed the first threshold, and in [Limit of light output], the third condition may be determined to be satisfied when only one of these voltage levels is less than the second threshold.

The determination unit 65 also determines whether the fourth condition is met based on the detection signal received from the light receiving unit X1. The determination unit 65 determines that the fourth condition is met when the light intensity received by the light receiving unit X1 exceeds a second predetermined value, that is, when the signal level (e.g., voltage) of the detection signal received from the light receiving unit X1 exceeds a reference value Rf1 (see FIG. 10B). Here, as an example, the second predetermined value is equal to the first predetermined value, that is, the reference value Rf1 is common to the determination of the second condition and the determination of the fourth condition.

The determination unit 65 determines that the skin 92 has switched from a contact state to a non-contact state when both the third condition and the fourth condition are satisfied. When the sensor unit S1 is omitted, the determination unit 65 may determine that the skin 92 has switched from a contact state to a non-contact state when only the fourth condition is satisfied.

When the determination result of the determination unit 65 indicates a switch to a non-contact state, the restriction unit 11 causes the drive unit 64 to stop driving the light source 21. In other words, when the proximity or release of contact (here, contact) of the skin 92 with the sensor unit S1 is detected (when the third condition is satisfied), the restriction unit 11 restricts the light output from the light emitting module M1. The restriction unit 11 causes the drive unit 64 to stop the supply of power to the light source 21. Therefore, it is possible to reduce situations in which light is unnecessarily output from the light emitting module M1, and usability can be improved. There is also an effect of saving power on the battery 23.

In particular, in this embodiment, as described above, in addition to the third condition, the limiting unit 11 limits the light output from the light emitting module M1 in accordance with the light intensity received by the light receiving unit X1 (here, when the fourth condition is satisfied). In other words, in this embodiment, the limiting unit 11 limits the light output from the light emitting module M1 in accordance with the detection result regarding the proximity or contact (here, contact) of the skin 92 with the sensor unit S1, in addition to the light intensity. This improves the reliability of the detection of the skin 92, and can reduce, for example, the possibility that the light output will be unintentionally limited by the user.

As described above, the "limitation of the optical output" is not limited to stopping the driving of the light source 21, and when the judgment result of the judgment unit 65 indicates a switch to a non-contact state, the limiting unit 11 may, for example, cause the output adjustment unit 63 to reduce the magnitude of the output (power density) of the light source 21.

As an example, FIG. 10A is a graph showing the change (on/off) in light output when the skin 92 switches from a contact state to a non-contact state at time t1, and then switches from the non-contact state back to a contact state at time t2. That is, in the example of FIG. 10A, the determination unit 65 determines that the third and fourth conditions are satisfied at time t1, and stops the light source 21 that was being driven. Also in the example of FIG. 10A, the determination unit 65 determines that the first and second conditions are satisfied at time t2, and starts driving the light source 21.

Incidentally, hysteresis (setting condition) may be set for the light intensity. For example, if the user tries to change the direction of the hair-cutting member 3 (head) while it is in contact with the skin 92 while using the hair-cutting device 1, the gap between the opening 31 and the skin 92 may widen, and the light intensity received by the light-receiving unit X1 may temporarily increase. As a result, the light output may be restricted in a way that is not desired by the user. Therefore, the second predetermined value for restricting the light output may be set higher than the first predetermined value for starting the light output. Conversely, the second predetermined value may be set lower than the first predetermined value, in which case the power saving effect is improved.

The determination unit 65 may also determine that the fourth condition is satisfied if the state in which the light intensity exceeds the second predetermined value continues for a predetermined period (e.g., several seconds to several tens of seconds) after the light intensity exceeds the second predetermined value. In other words, the determination unit 65 may determine whether the fourth condition is satisfied by adding a condition (set condition) of "duration" related to the light intensity.

The determination unit 65 may also determine that the fourth condition is satisfied if the average value of the light intensity over a certain period of time exceeds a second predetermined value. In other words, the determination unit 65 may also determine whether the fourth condition is satisfied by adding a condition (set condition) of "average value" regarding the light intensity.

In other words, the limiting unit 11 may limit the light output from the light emitting module M1 based on the light intensity exceeding a certain value (second predetermined value) as well as on the set conditions related to the light intensity (e.g., the above-mentioned hysteresis, duration, average value, etc.). This reduces the possibility that the light output will be stopped even when the user still intends to continue using the hair cutting device 1. Therefore, it is possible to reduce the possibility that the light output will be unintentionally limited by the user.

Of course, the above-mentioned setting conditions may also be applied to the second condition for determining "start of light output." For example, the determination unit 65 may determine that the second condition is satisfied when the state in which the light intensity is less than the first predetermined value continues for a predetermined period of time.

[Operation example 1]
Next, a first operation example of the hair-cutting device 1 including the above-mentioned control circuit 6 will be described with reference to Fig. 11. Fig. 11 is a flow chart showing an operation example regarding switching between the operation modes (first mode and second mode) of the hair-cutting device 1.

The hair cutting device 1 first determines whether the operation mode of the light source 21 is the first mode (ST1). At this time, if the operation mode is the first mode (ST1: Yes), the hair cutting device 1 sets the time length of the light emission period T1 to 1/10,000th of a second or less and drives the light source 21 with the drive unit 64 (ST2). On the other hand, if the operation mode is not the first mode (ST1: No), the hair cutting device 1 skips step ST2 and moves to step ST3.

In step ST3, the hair cutting device 1 determines whether the operation mode of the light source 21 is the second mode. If the operation mode is the second mode (ST3: Yes), the hair cutting device 1 sets the time length of the light emission period T1 to 1/100th of a second or more and drives the light source 21 with the drive unit 64 (ST4). On the other hand, if the operation mode is not the second mode (ST3: No), the hair cutting device 1 skips step ST4 and ends the process.

The hair cutting device 1 repeatedly executes the above steps ST1 to ST4. The flowchart shown in FIG. 11 is merely an example of the operation of the hair cutting device 1, and for example, the order of the steps may be changed as appropriate, and steps may be added or omitted as appropriate.

[Operation example 2]
Next, a second operation example of the hair-cutting device 1 including the above-mentioned control circuit 6 will be described with reference to Fig. 12. Fig. 12 is a flow chart showing an operation example of the determination process of the hair-cutting device 1.

First, the hair cutting device 1 receives an operation to turn on the main power supply through the operation unit 26 (ST11). The hair cutting device 1 goes into a standby state, executes a determination process, and monitors the detection signals from the sensor unit S1 and the light receiving unit X1 (ST12: a detection step for detecting the contact state of the skin 92, and an acquisition step for acquiring information regarding the light intensity).

When the skin 92 is in contact with the hair-cutting device 1 (ST13: Yes), that is, when it is determined based on the detection signal that both the first and second conditions are satisfied, the hair-cutting device 1 starts driving the light source 21 (ST14: light emission step). Note that the hair-cutting device 1 continues in a standby state without starting driving the light source 21 until the skin 92 is in contact with the hair-cutting device 1 (ST13: No).

When the light source 21 is being driven and the skin 92 is not in contact with the light source 21 (ST15: Yes), that is, when the hair cutting device 1 determines based on the detection signal that both the third and fourth conditions are satisfied, the hair cutting device 1 stops driving the light source 21 (ST16). Note that the hair cutting device 1 continues driving the light source 21 until the skin 92 is not in contact with the light source 21 (ST15: No).

The flowchart shown in FIG. 12 is merely an example of the operation of the hair cutting device 1, and for example, the order of processes may be changed as appropriate, and processes may be added or omitted as appropriate.

(3) Functions Next, functions that can be expected from the hair cutting device 1 according to this embodiment will be described.

First, the basic function of the hair-cutting device 1, cutting the hair 91, is achieved by the mechanism described in the section "(2.4) Usage Examples."

In this embodiment, the first emitted light Op1 from the light emitting unit 40 has a wavelength of 400 nm or more and 700 nm or ^less , and is therefore easily absorbed by chromophores contained in the hair 91, such as keratin and water. Furthermore, at least when the hair 91 is cut, the power density of the light passing through the optical waveguide 4 is 50 kW/cm2 or more. Therefore, the first emitted light Op1 emitted from the light emitting unit 40 to the hair 91 can also have a power density (50 kW/ ^cm2 or more) sufficient to cut the hair 91.

Next, the action on the skin 92, which is a secondary function of the hair cutting device 1, will be described. In this embodiment, since the second emitted light Op2 of the light emitting unit 40 has a wavelength of 400 nm or more and 700 nm or less, it is possible to expect an action on the skin 92 such as sterilization or activation. In other words, when the second emitted light Op2 emitted to the skin 92 has a wavelength of, for example, 400 nm or more and 450 nm or less, a sterilization action against acne bacteria and the like present on the skin 92 can be expected. In particular, as illustrated in Figures 8A and 8B, when a protuberance 922 such as acne is present around the hair 91 on the skin 92, the second emitted light Op2 is directly emitted to the protuberance 922, and a more effective sterilization action and the like can be expected. Furthermore, when the second emitted light Op2 has a wavelength of, for example, 450 nm or more and 700 nm or less, an activation action on the skin 92 can be expected. In other words, by emitting the second emitted light Op2 to the skin 92, the skin 92 is activated, and the effect of improving skin quality, or the so-called "skin beautifying effect," can be expected.

In addition, in this embodiment, as described in the section "(2.3.7) Sensor unit", the sensor unit S1 is provided, so that control can be realized using the detection results regarding the contact state of the skin 92. For example, as described in the section "(2.6) Control circuit", the contact state of the skin 92 can be determined (estimated) based on the detection signal from the sensor unit S1, and light output can be started or stopped. Therefore, a hair cutting device 1 with improved usability can be provided.

In addition, since the sensor unit S1 is disposed in the area surrounding the optical waveguide 4, it becomes easier to detect the contact state with the skin 92, for example, when the user is cutting hair 91.

Furthermore, since the sensor unit S1 is arranged around the opening 31, the contact state of the skin 92 can be easily detected even in a configuration in which an opening 31 is provided, as in this embodiment.

In addition, the sensor unit S1 is arranged so that its length direction is parallel to the direction of the optical axis C1 of the optical waveguide 4, which makes it even easier to detect the contact state of the skin 92. Furthermore, there are two sensor units S1 (the first sensor unit S11 and the second sensor unit S12) arranged parallel to the direction of the optical axis C1, which further improves the reliability of detection of the skin 92.

In particular, since the first sensor unit S11 and the second sensor unit S12 are disposed on both sides of the optical waveguide 4 in the width direction W1, there is a high possibility that the skin 92 will be in contact (or close to) the first sensor unit S11 and the second sensor unit S12 at the same time during use. Furthermore, compared to when there is only one sensor unit S1, it is possible to control the contact state of the skin 92 in a more diverse pattern. For example, when the skin 92 moves from a state in which it is in contact with both the first sensor unit S11 and the second sensor unit S12 to a state in which it is separated from only one of them, the light output is weakened, and when it moves from a state in which it is separated from both, the light output is stopped, making it easier to perform stepwise light output control.

In addition, in this embodiment, as explained in the section "(2.3.8) Light receiving unit and filter unit", the light receiving unit X1 is provided, so that it is possible to realize control using the detection result regarding the light intensity from the contact surface (301, 501) side, for example. For example, as explained in the section "(2.6) Control circuit", the contact state of the skin 92 can be determined (estimated) based on the detection signal from the light receiving unit X1, and light output can be started or stopped. Therefore, it is possible to provide a hair cutting device 1 with improved usability.

The light receiving unit X1 is also positioned inside the opening 31 in the cover 30. Therefore, the light intensity from the contact surface (301, 501) side received by the light receiving unit X1 can be changed more significantly depending on the contact state (or proximity state) of the skin 92 with the contact surface (301, 501).

In particular, the first distance L1 from the opening surface 310 to the light receiving part X1 is greater than the second distance L2 from the opening surface 310 to the optical waveguide 4. This reduces the possibility that, for example, the hair 91 inserted through the opening 31 will come into contact with the light receiving part X1. Therefore, the light receiving part X1 is less likely to become an obstacle when cutting the hair 91.

(4) Modifications This embodiment is merely one of various embodiments of the present disclosure. This embodiment can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. In addition, all drawings referred to in this disclosure are schematic drawings, and the ratios of sizes and thicknesses of each component in the drawings do not necessarily reflect the actual dimensional ratios.

Furthermore, functions similar to those of the hair-cutting device 1 (particularly the control circuit 6) according to the above embodiment may be embodied in a hair-cutting method, a computer program, or a non-temporary recording medium on which a computer program is recorded. Below, we list some variations of the above embodiment. The variations described below can be applied in appropriate combinations.

The hair cutting device 1 (particularly the control circuit 6) in the present disclosure includes a computer system. The computer system is mainly composed of a processor and a memory as hardware. The function of the control circuit 6 in the present disclosure is realized by the processor executing a program recorded in the memory of the computer system. The program may be pre-recorded in the memory of the computer system, provided through an electric communication line, or recorded and provided in a non-transitory recording medium such as a memory card, an optical disk, or a hard disk drive that can be read by the computer system. The processor of the computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large scale integrated circuit (LSI). The integrated circuits such as IC or LSI referred to here are called differently depending on the degree of integration, and include integrated circuits called system LSI, VLSI (Very Large Scale Integration), or ULSI (Ultra Large Scale Integration). Furthermore, a field-programmable gate array (FPGA) that is programmed after the manufacture of the LSI, or a logic device that can reconfigure the connection relationship inside the LSI or reconfigure the circuit partition inside the LSI, can also be adopted as a processor. The multiple electronic circuits may be integrated into one chip, or may be distributed across multiple chips. The multiple chips may be integrated into one device, or may be distributed across multiple devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Therefore, the microcontroller is also composed of one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

In addition, it is not essential that the multiple functions of the hair cutting device 1 are concentrated in one housing. For example, the components of the hair cutting device 1 may be distributed across multiple housings. Conversely, the multiple functions of the hair cutting device 1 may be concentrated in one housing. Furthermore, at least some of the functions of the hair cutting device 1, for example, some of the functions of the hair cutting device 1, may be realized by the cloud (cloud computing) or the like.

(4.1) First Modification A hair-cutting device 1A according to a first modification of the present embodiment will be described with reference to Fig. 13. However, in the following first modification, components that are substantially common to the hair-cutting device 1 will be given the same reference numerals, and descriptions thereof may be omitted as appropriate.

As shown in FIG. 13, the overall appearance of the hair-cutting device 1A is similar to that of an electric shaver. The device body 2 of the hair-cutting device 1A is a long, thin cylinder, and a hair-cutting member 3 (head) is attached to the tip of the device body 2. In particular, the hair-cutting device 1A differs from the hair-cutting device 1 in that the longitudinal direction of the hair-cutting member 3 (head) and the optical axis C1 of the optical waveguide 4 are perpendicular to the longitudinal direction of the device body 2.

It is preferable that the hair-cutting device 1A is provided with one or more mirrors inside the hair-cutting member 3 or the device body 2, which reflect the light emitted from the optical system 22 inside the case 20 of the device body 2 so as to guide it to the light-receiving surface 40A inside the ferrule 71.

The hair cutting device 1A configured in this manner also has two sensor units S1 and a light receiving unit X1. Therefore, it is possible to provide a hair cutting device 1A with improved usability.

The external shape of the "hair cutting device" in this disclosure is not limited to the shape of the hair cutting device 1 and the hair cutting device 1A, and may also have a T-shaped appearance in which the longitudinal length of the hair-cutting member 3 (head) is greater than the width of the device body 2. The external shape of the "hair cutting device" may also be a Y-shape, an L-shape, or a card-shaped appearance.

(4.2) Second Modification A hair-cutting device 1B according to a second modification of the present embodiment will be described with reference to Fig. 14. However, in the second modification below, components that are substantially common to the hair-cutting device 1 will be given the same reference numerals, and descriptions thereof may be omitted as appropriate.

The hair-cutting device 1B differs from the hair-cutting device 1 in that the number of sensor units S1 is four, as shown in FIG. 14. Specifically, the hair-cutting device 1B further includes two other sensor units S1 in addition to the first sensor unit S11 and the second sensor unit S12 of the hair-cutting device 1. These two other sensor units S1 are also arranged around the opening 31. In particular, these two other sensor units S1 are arranged on both sides of the optical waveguide 4 in the direction of the optical axis C1.

Hereinafter, the sensor unit S1 on the positive side of the X-axis from the opening 31 may be referred to as the "third sensor unit S13," and the sensor unit S1 on the negative side of the X-axis from the opening 31 may be referred to as the "fourth sensor unit S14."

The third sensor unit S13 and the fourth sensor unit S14, like the first sensor unit S11 and the second sensor unit S12, constitute, for example, a capacitive touch sensor (touch switch).

The third sensor unit S13 and the fourth sensor unit S14 may be capacitance-type proximity sensors that detect the proximity of an object by increasing the sensitivity, in which case they may serve as parts for detecting the proximity state of the skin 92. The third sensor unit S13 and the fourth sensor unit S14 are not limited to capacitance-type sensors, and may be optical sensors, induction sensors, magnetic sensors, or the like. In particular, the third sensor unit S13 and the fourth sensor unit S14 may constitute sensors with a detection method different from that of the first sensor unit S11 and the second sensor unit S12.

Each of the third sensor unit S13 and the fourth sensor unit S14 is electrically connected to the control circuit 6 via a connection line.

The third sensor unit S13 and the fourth sensor unit S14 have electrodes S2 of the same shape and dimensions. The third sensor unit S13 and the fourth sensor unit S14 also have protective covers S3 of the same shape and dimensions.

Here, the first sensor unit S11 and the second sensor unit S12 are arranged along a pair of long sides of a rectangle that is long in the direction of the X-axis and forms the periphery of the opening 31, and the third sensor unit S13 and the fourth sensor unit S14 are arranged along a pair of short sides.

The dimensions of each of the third sensor unit S13 and the fourth sensor unit S14 in the Z-axis direction are, for example, approximately equal to the width dimension (dimension in the Z-axis direction) of the opening 31. The dimensions of each of the third sensor unit S13 and the fourth sensor unit S14 in the X-axis direction are, for example, smaller than the width dimension (dimension in the Z-axis direction) of the opening 31. In other words, the detection area of each of the third sensor unit S13 and the fourth sensor unit S14 is, for example, sufficiently smaller than the detection area of each of the first sensor unit S11 and the second sensor unit S12.

In this modified example, as an example, the first sensor unit S11 and the second sensor unit S12 are used as the "main sensor unit", and the third sensor unit S13 and the fourth sensor unit S14 are used as the "sub-sensor unit".

In the hair-cutting device 1B, the determination unit 65 determines whether the first condition is met based on the detection signals received from the four sensor units S1. That is, the determination unit 65 detects the contact state of the skin 92 with the four sensor units S1 (detection step). The determination unit 65 determines that the first condition is met when both voltage levels of the main sensor units (S11, S12) exceed a threshold value (first threshold value) and when at least one of the voltage levels of the sub-sensor units (S13, S14) exceeds the threshold value. That is, the hair-cutting device 1B starts light output when the skin 92 comes into contact with two main sensor units and one (or two) sub-sensor unit.

However, the judgment pattern for the first condition is not limited to the above. For example, the judgment unit 65 may judge that the first condition is satisfied when any one of the voltage levels of the four sensor units S1 exceeds a threshold value. Alternatively, the judgment unit 65 may judge that the first condition is satisfied when all of the voltage levels of the four sensor units S1 exceed a threshold value.

The detection area of the sub-sensor unit is smaller than the detection area of the main sensor unit. Therefore, if the change in capacitance is also small, the threshold value for the sub-sensor unit may be smaller than the threshold value for the main sensor unit (first threshold value).

In addition, in the hair-cutting device 1B, the determination unit 65 determines whether or not the third condition is met based on the detection signals received from the four sensor units S1. The determination unit 65 determines that the third condition is met when any two or more of the voltage levels of the four sensor units S1 are below the threshold. In other words, the hair-cutting device 1B limits the light output when two or more pieces of skin 92 are separated from the sensor units S1.

However, the judgment pattern for the third condition is not limited to the above. For example, the judgment unit 65 may judge that the third condition is met when any one of the voltage levels of the four sensor units S1 falls below the threshold value. Alternatively, the judgment unit 65 may judge that the third condition is met when, for example, the voltage levels of all of the sensor units S1 that were in contact fall below the threshold value.

Furthermore, various control patterns may be set for the light output. For example, the hair cutting device 1B may perform a first light output control when two main sensor units are contacted, a second light output control when three of the four sensor units S1 are contacted, and a third light output control when all four sensor units S1 are contacted. The magnitude of the output (power density) of the light source 21 may be set to increase stepwise in the order of the first light output control, the second light output control, and the third light output control.

Even in the configuration of the hair-cutting device 1B described above, the contact state of the skin 92 can be determined (estimated) based on the detection signals from the four sensor units S1, and light output can be started or stopped. Therefore, a hair-cutting device 1B with improved usability can be provided. In particular, by arranging the two sensor units S1 on both sides of the optical waveguide 4 in the direction of the optical axis C1, it becomes possible to detect even more diverse patterns regarding the contact state of the skin 92.

As another example of the hair cutting device 1B, the sensor unit S1 may have a single electrode S2 formed in a rectangular frame shape surrounding the periphery of the opening 31.

As yet another example of the hair cutting device 1B, a pair of sensor units S1 may be provided, each having an electrode S2 formed in an L-shape so as to surround the periphery of the opening 31. One electrode S2 of the pair of sensor units S1 may be formed in an L-shape along one long side and one short side of the four sides that form the periphery of the opening 31, and the other electrode S2 may be formed in an L-shape along the other long side and the other short side of the four sides.

(4.3) Third Modification A hair-cutting device 1C according to a third modification of the present embodiment will be described with reference to Fig. 15A. However, in the following third modification, components that are substantially common to the hair-cutting device 1 will be given the same reference numerals, and descriptions thereof may be omitted as appropriate.

Figure 15A is a cross-sectional view of the hair-cutting member 3 of the hair-cutting device 1C taken along the Y-Z plane at approximately the center in the X-axis direction. As shown in Figure 15A, the hair-cutting device 1C differs from the hair-cutting device 1 in that it is equipped with two light receiving units X1. The two light receiving units X1 (referred to as the first light receiving unit X11 and the second light receiving unit X12) are disposed on the top surface 302 inside the cover 30 (the storage space SP1). The top surface 302 is a surface facing the negative side of the Y-axis and is a surface that can face the skin 92.

The first light receiving unit X11 is disposed in an area at the end of the top surface 302 on the positive side of the Z axis. The second light receiving unit X12 is disposed in an area at the end of the top surface 302 on the negative side of the Z axis. Therefore, the light receiving surface X10 of each light receiving unit X1 faces the negative side of the Y axis. In addition, a filter unit B1 is laminated on the light receiving surface X10 of each light receiving unit X1.

In the hair cutting device 1C, the light emitting module M1 is positioned in the Y-axis direction so that it is less likely to be an obstacle to each light receiving unit X1 that receives external light. In other words, each light receiving unit X1 can more easily receive light from the contact surface (301, 501) side directly. Therefore, the reliability of detection of light intensity from the contact surface (301, 501) side, for example, is further improved.

As another example of the arrangement of the two light receiving units X1, as shown in FIG. 15B, the two light receiving units X1 may be arranged on mutually opposing inner surfaces 303 inside the cover 30 (storage space SP1). In this case, the light receiving surface X10 of the first light receiving unit X11 faces the negative side of the Z axis, and the light receiving surface X10 of the second light receiving unit X12 faces the positive side of the Z axis.

As yet another example of the arrangement of the two light receiving units X1, as shown in FIG. 15C, the two light receiving units X1 may be arranged at two corners (corners between the top surface 302 and each inner surface 303) inside the cover 30 (storage space SP1). In this case, the light receiving surface X10 of the first light receiving unit X11 faces in a direction inclined at about 45 degrees to the negative side of the Z axis with respect to the Y axis direction, and the light receiving surface X10 of the second light receiving unit X12 faces in a direction inclined at about 45 degrees to the positive side of the Z axis with respect to the Y axis direction.

(4.4) Other Modifications It has been described that the hair-cutting device 1 accepts the on/off switching of the main power supply through the operation unit 26. However, the hair-cutting device 1 may be further configured to accept the start of driving the light source 21, i.e., the start of light output from the light source 21, through the operation unit 26. In this case, the function of the control circuit 6 to automatically start driving the light source 21 based on the detection signals from the sensor unit S1 and the light receiving unit X1 may be omitted. However, it is preferable that the control circuit 6 has at least a function to automatically limit the light output based on the detection signals from the sensor unit S1 and the light receiving unit X1. The function of automatically limiting the light output is expected to save power on the battery 23 and improve safety.

The hair-cutting device 1 may also be configured to automatically switch the main power supply on and off based on a detection signal from the sensor unit S1. In this case, for example, the sensor unit S1 may include a switch that opens and closes a contact. In this case, the hair-cutting device 1 switches the main power supply on when the sensor unit S1 closes the contact due to pressure from the skin 92, and further starts driving the light source 21 automatically. In this case, the user is saved the trouble of operating the operation unit 26, further improving usability.

The sensor unit S1 may constitute an electrical current type sensor. For example, a pair of electrodes of the sensor unit S1 (the electrode S2 of the first sensor unit S11 and the electrode S2 of the second sensor unit S12) may constitute an anode and a cathode, respectively. The control circuit 6 may apply a voltage between these electrodes and determine the contact state of the skin 92 by detecting a current flowing between the electrodes via the human body when the skin 92 contacts these electrodes.

The sensor unit S1 may also be a proximity sensor for detecting the proximity state of the skin 92, rather than the contact state of the skin 92. In this case, the sensor unit S1 may constitute a distance sensor for detecting the distance to the skin 92.

The sensor unit S1 may also be configured as a pressure sensor whose resistance value changes when it receives pressure (pressure) from the skin 92.

When two or more sensor units S1 are provided, the two or more sensor units S1 may constitute sensors with different detection methods.

For example, the device main body 2 (case 20) that houses the light source 21 etc. is assumed to correspond to a grip, but a grip section may be provided separately from the case 20, and the case 20 and the grip section may be connected. The contents in the case 20 may be distributed and housed in the case 20 and the grip section.

The operation unit 26 is not limited to a mechanical switch, and may be a touch switch, an optical or capacitive non-contact switch, a gesture sensor, or the like. Furthermore, the operation unit 26 may be, for example, a communication unit that receives an operation signal from an external terminal such as a smartphone, or a voice input unit that receives voice operations from the user.

The hair-cutting device 1 may also be combined with a shaver (including an electric shaver with a driven blade) that cuts the hair 91 with a physical "blade." In this case, the hair-cutting device 1 has a physical "blade" in addition to the light emitting unit 40, and can cut the hair 91 with both the light emitted from the light emitting unit 40 and the physical "blade."

Furthermore, the optical waveguide 4 is not limited to an optical fiber whose core 41 and cladding 42 are made of synthetic quartz, and may be, for example, an optical fiber made of quartz (SiO ₂ ) or plastic. An example of a plastic optical fiber is an optical fiber whose cladding 42 is made of a fluorine-based polymer or the like and whose core 41 is made of a fully fluorinated polymer, polymethyl methacrylate, polycarbonate, or the like. Furthermore, the optical waveguide 4 may be a slab waveguide, a rectangular optical waveguide, a photonic crystal fiber, or the like.

In addition, the optical waveguide 4 only needs to have a core portion 41 as a minimum configuration, and the cladding portion 42 may be omitted as appropriate.

Furthermore, it is not an essential configuration of the hair cutting device 1 that the refractive index of the adhesive member 52 in the holding member 5 is smaller than the refractive index of the light emitting section 40 (core section 41). In other words, the refractive index of the adhesive member 52 may be equal to or greater than the refractive index of the core section 41.

Furthermore, it is not an essential configuration of the hair-cutting member 3 and the hair-cutting device 1 that the refractive index of the fixing member F1 in the holder portion H1 is smaller than the refractive index of the core portion 41. In other words, the refractive index of the fixing member F1 may be equal to or greater than the refractive index of the core portion 41. Similarly, it is not an essential configuration of the hair-cutting member 3 and the hair-cutting device 1 that the refractive index of the adhesive member G1 in the ferrule 71 is smaller than the refractive index of the core portion 41. In other words, the refractive index of the adhesive member G1 may be equal to or greater than the refractive index of the core portion 41.

The light source 21 is not limited to emitting light of a single wavelength, and may emit light of multiple wavelengths, for example. In this case, the light source 21 may emit light of multiple wavelengths simultaneously, or may emit light of multiple wavelengths by sequentially switching between them. In this configuration, the light emitted from the light emitting unit 40 to the hair 91 (first emitted light Op1) can target multiple chromophores corresponding to multiple wavelengths, so that the bonds of multiple types of molecules can be destroyed, and the cutting efficiency of the hair 91 can be improved.

The hair-cutting member 3 may also include a plurality of optical waveguides 4. In this case, the hair-cutting member 3 can cut the hair 91 by emitting light to the hair 91 from the light emitting portion 40 of each of the plurality of optical waveguides 4. Here, the plurality of optical waveguides 4 may transmit light of the same wavelength, or may transmit light of a plurality of different wavelengths. In this case, the plurality of optical waveguides 4 may be arranged in the ferrule 71, concentrated toward the center. Alternatively, a plurality of ferrules 71 may be provided so as to correspond one-to-one with the optical waveguides 4.

In addition, the operation mode of the light source 21 is switched between the first mode and the second mode manually, but this is not limiting, and the switching between the first mode and the second mode may be performed automatically. For example, the determination unit 65 may automatically switch between the first mode and the second mode depending on the contact state of the skin 92.

The battery 23 is not limited to a secondary battery, and may be a primary battery. Furthermore, the hair-cutting device 1 is not limited to being battery-powered, and may be powered by an external power source, such as a system power source (commercial power source). In this case, the battery 23 in the hair-cutting device 1 may be omitted.

The power density of the light passing through the optical waveguide 4 may be adjusted by something other than the output from the light source 21. For example, the power density of the light passing through the optical waveguide 4 may be adjusted by the optical system 22 or an optical filter included in the optical waveguide 4. Alternatively, the power density of the light passing through the optical waveguide 4 may be adjusted by changing the radius of curvature of the optical waveguide 4. The power density of the light passing through the optical waveguide 4 may be adjusted by exposing the core portion 41 from a part of the optical waveguide 4 and allowing a part of the light to leak from the core portion 41.

In addition, a mirror may be arranged on the end surface 40B of the optical waveguide 4 opposite the light receiving surface 40A, so that light reaching the tip of the optical waveguide 4 is reflected by the mirror into the optical waveguide 4.

The function of acting on the skin 92 is merely a secondary function of the hair-cutting device 1 and can be omitted as appropriate. In other words, the hair-cutting device 1 only needs to have the basic function of cutting the hair 91.

In addition, when comparing two values, "greater than or equal to" includes both the cases where the two values are equal and where one of the two values exceeds the other. However, without being limited to this, "greater than or equal to" here may be synonymous with "greater than," which includes only the cases where one of the two values exceeds the other. In other words, whether or not the cases where the two values are equal can be included can be changed arbitrarily depending on the settings of thresholds, etc., so there is no technical difference between "greater than or equal to" and "greater than." Similarly, "less than" may be synonymous with "less than or equal to."

The hair-cutting device 1 may include an attachment that is removably attached to the cover 30 of the hair-cutting member 3. The attachment may increase the height of the light emitting portion 40 from the surface 921 of the skin 92.

(5) Summary As described above, the hair-cutting device (1, 1A to 1C) according to the first aspect includes a light-emitting module (M1), a contact surface (301, 501), and a light-receiving unit (X1). The light-emitting module (M1) has a light guide (4) including a core portion (41), and cuts the hair (91) by emitting light to the hair (91) protruding from the skin (92). The contact surface (301, 501) is located around the light guide (4) and contacts the skin (92). The light-receiving unit (X1) receives light from the contact surface (301, 501) side. According to the first aspect, for example, control using the detection result regarding the light intensity from the contact surface (301, 501) side can be realized, and a hair-cutting device (1, 1A to 1C) with improved usability can be provided.

The hair-cutting device (1, 1A-1C) according to the second aspect is the first aspect, and further includes a cover (30). The cover (30) is configured to cover the light-emitting module (M1), and has an opening (31) that exposes at least a part of the core part (41) to the outside. The light-receiving part (X1) is disposed inside the opening (31) in the cover (30). According to the second aspect, the light intensity from the side of the contact surface (301, 501) received by the light-receiving part (X1) can be changed more significantly depending on the contact state (or proximity state) of the skin (92) with the contact surface (301, 501).

Regarding the hair cutting device (1, 1A to 1C) according to the third aspect, in the second aspect, the first distance (L1) is greater than the second distance (L2) in the vertical direction of the opening surface (310) of the opening (31). The first distance (L1) is the distance from the opening surface (310) to the light receiving unit (X1). The second distance (L2) is the distance from the opening surface (310) to the optical waveguide (4). According to the third aspect, for example, it is possible to reduce the possibility that the hair (91) inserted from the opening (31) will come into contact with the light receiving unit (X1).

The hair cutting device (1, 1A-1C) according to the fourth aspect is any one of the first to third aspects and further includes a filter unit (B1). The filter unit (B1) reflects or absorbs light in a specific wavelength region emitted from the light emitting module (M1) and transmits light outside the specific wavelength region. According to the fourth aspect, even if the light receiving unit (X1) is placed in a position where it receives light emitted from the light emitting module (M1), the light receiving accuracy of the light from the contact surface (301, 501) side is improved. In other words, the design freedom regarding the position of the light receiving unit (X1) is improved.

Regarding the hair cutting device (1, 1A-1C) according to the fifth aspect, in the fourth aspect, the filter unit (B1) is arranged to cover the light receiving surface (X10) of the light receiving unit (X1). According to the fifth aspect, the light receiving accuracy for light from the contact surface (301, 501) side is further improved.

The hair cutting device (1, 1A-1C) according to the sixth aspect is any one of the first to fifth aspects and further includes a limiting unit (11). The limiting unit (11) limits the light output from the light emitting module (M1) according to the light intensity received by the light receiving unit (X1). According to the sixth aspect, it is possible to reduce situations in which unnecessary light output is produced from the light emitting module (M1), and usability can be further improved.

Regarding the hair cutting device (1, 1A-1C) according to the seventh aspect, in the sixth aspect, the limiting unit (11) limits the light output from the light emitting module (M1) based on the set conditions regarding the light intensity in addition to the light intensity exceeding a certain value. According to the seventh aspect, it is possible to reduce the possibility that the light output will be unintentionally limited by the user.

The hair cutting device (1, 1A-1C) according to the eighth aspect further includes a sensor unit (S1) for detecting the proximity or contact state of the skin (92) in the sixth or seventh aspect. The limiting unit (11) limits the light output from the light emitting module (M1) according to the detection result regarding the proximity or contact of the skin (92) to the sensor unit (S1) in addition to the light intensity. According to the eighth aspect, it is possible to reduce the possibility that the light output will be unintentionally limited by the user.

The hair cutting device (1, 1A-1C) according to the ninth aspect further includes an execution unit (12) that executes light output from the light emission module (M1) when the light intensity received by the light receiving unit (X1) falls below a predetermined value in any one of the first to eighth aspects. According to the ninth aspect, for example, the light output can be easily executed automatically by the user bringing the skin (92) close to or into contact with the contact surface (301, 501), and usability can be further improved.

The hair-cutting method according to the tenth aspect includes a light emission step and an acquisition step. In the light emission step, light is emitted from a light emission module (M1) having a light guide (4) including a core portion (41) to the hair (91) protruding from the skin (92), thereby cutting the hair (91). In the acquisition step, information on the light intensity from the contact surface (301, 501) that is around the light guide (4) and in contact with the skin (92) is acquired. According to the tenth aspect, for example, control can be realized using the detection result regarding the light intensity from the contact surface (301, 501), and a hair-cutting method with improved usability can be provided.

The configurations according to the second to ninth aspects are not essential for the hair cutting device (1, 1A to 1C) and may be omitted as appropriate.

The hair-cutting device can be used for cutting various types of human or non-human animal hair in various fields, such as home use, beauty, medicine, or nursing care.

1, 1A to 1C Hair cutting device 11 Limiting unit 12 Execution unit 30 Cover 301 Cover side contact surface (contact surface)
31 Opening 310 Opening surface 4 Optical waveguide 41 Core portion 501 Module side contact surface (contact surface)
91 Hair 92 Skin B1 Filter section L1 First distance L2 Second distance M1 Light emitting module S1 Sensor section X1 Light receiving section X10 Light receiving surface

Claims (7)

a light emitting module having an optical waveguide including a core portion and configured to emit light to a hair protruding from the skin to cut the hair;
a contact surface surrounding the optical waveguide and adapted to contact the skin;
A light receiving unit that receives light from the contact surface side, the light including external light entering from the outside ;
a limiting unit that stops the light output from the light emitting module in accordance with the light intensity received by the light receiving unit;
a filter section that reflects or absorbs light in a specific wavelength region emitted from the light emitting module and transmits light other than the specific wavelength region;
Equipped with
Hair cutting device. a cover configured to cover the light emitting module and having an opening for exposing at least a portion of the core to the outside;
The light receiving unit is disposed on the inside of the opening in the cover.
A hair cutting device according to claim 1. a first distance from the opening surface to the light receiving unit in a direction perpendicular to the opening surface of the opening is greater than a second distance from the opening surface to the optical waveguide;
A hair cutting device according to claim 2. The filter unit is disposed so as to cover the light receiving surface of the light receiving unit.
A hair cutting device according to any one of claims 1 to 3. The limiting unit stops the light output from the light emitting module based on a setting condition related to the light intensity in addition to the light intensity exceeding a certain value.
A hair cutting device according to any one of claims 1 to 4. Further comprising a sensor unit for detecting a proximity state or a contact state of the skin,
The limiting unit stops the light output from the light emitting module in response to a detection result regarding the proximity or contact of the skin with the sensor unit in addition to the light intensity.
A hair cutting device according to any one of claims 1 to 5. and an execution unit that executes light output from the light emitting module when the light intensity is less than a predetermined value.
A hair cutting device according to any one of claims 1 to 6.