JP7117663B2 - lighting equipment - Google Patents

Description

The present invention relates to a lighting device using laser light as a light source.

Conventionally, there is known a lighting device that emits light from a phosphor using laser light as excitation light and converts the light into a desired light color for illumination (see, for example, Patent Document 1). In such a lighting device, laser light output from a laser light source is guided to a lamp (lamp section) via an optical fiber (optical fiber cable). The fluorescent material in the lamp is excited by the laser light that has passed through the optical fiber, so that the lamp emits illumination light of a desired color.

JP 2015-15146 A

By the way, when assembling an illumination device, for example, during manufacturing or after maintenance, in order to ensure that the laser light enters the optical fiber, the laser light emitted from the laser light source is accurately aligned with the incident surface of the optical fiber. must be positioned at In other words, it is desired to increase the certainty of positioning between the laser light source and the optical fiber.

SUMMARY OF THE INVENTION An object of the present invention is to provide an illumination device that can increase the reliability of positioning between the light source and the optical fiber during assembly.

A lighting device according to an aspect of the present invention includes a semiconductor laser light source, and by controlling a supply current to the semiconductor laser light source, a first light emission mode that emits a first light and a second light emission mode that emits a lower emission intensity than the first light. A switching unit for switching between a second emission mode for emitting light, an optical fiber for guiding the first light or the second light emitted by the semiconductor laser light source, and an aperture member arranged between the semiconductor laser light source and the optical fiber. The aperture member transmits the first light emitted from the semiconductor laser light source in the first emission mode, and the irradiation range of the first light out of the second light emitted from the laser light source in the second emission mode has an opening that blocks light that does not overlap with the

According to the illumination device of the present invention, it is possible to increase the reliability of positioning the laser light source and the optical fiber during assembly.

FIG. 1 is a perspective view showing how a lighting device according to an embodiment is used. FIG. 2 is a schematic diagram showing the optical configuration of the illumination device according to the embodiment. FIG. 3 is a graph showing light emission characteristics of a semiconductor laser element that is a laser light source according to the embodiment. FIG. 4 is an enlarged view showing the positional relationship between the aperture member, laser light, and LED light according to the embodiment. FIG. 5 is a plan view showing a schematic configuration of a diaphragm member according to the embodiment. FIG. 6 is a block diagram showing the control configuration of the lighting device according to the embodiment. FIG. 7A is an explanatory diagram showing progress of LED light in the lighting device according to the embodiment. FIG. 7B is an explanatory diagram showing the progress of LED light in the lighting device according to the comparative example. FIG. 8A is an actual measurement image showing the emission intensity profile of LED light between the diaphragm member and the dichroic mirror according to the embodiment. FIG. 8B is an actual measurement image showing the emission intensity profile of LED light between the collimating lens and the dichroic mirror according to the comparative example. FIG. 9 is a graph showing the emission intensity distribution of the LED light according to the embodiment and the emission intensity distribution of the LED light according to the comparative example superimposed. FIG. 10A is a schematic diagram showing an emission intensity profile of LED light with respect to one end surface of an optical fiber according to the embodiment. FIG. 10B is a schematic diagram showing an emission intensity profile of LED light with respect to one end surface of an optical fiber according to a comparative example. FIG. 11A is an actual measurement image showing the emission intensity profile of LED light with respect to one end surface of the optical fiber according to the embodiment. FIG. 11B is an actual measurement image showing the emission intensity profile of LED light with respect to one end face of the optical fiber according to the comparative example. FIG. 12 is a graph showing the emission intensity distribution of the LED light according to the embodiment and the emission intensity distribution of the LED light according to the comparative example superimposed. FIG. 13 is a schematic diagram showing an optical configuration of a lighting device according to a modification.

A lighting device according to an embodiment of the present invention will be described below with reference to the drawings. It should be noted that each of the embodiments described below is a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement of components, connection forms, and the like shown in the following embodiments are examples, and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in independent claims representing the highest level concept of the present invention will be described as optional constituent elements.

Each figure is a schematic diagram and is not necessarily strictly illustrated. Moreover, in each figure, the same code|symbol is attached|subjected about the same component.

[Embodiment]
Embodiments will be described below. First, the mode of use of the lighting device according to the embodiment will be described. FIG. 1 is a perspective view showing how a lighting device according to an embodiment is used. As shown in FIG. 1, the lighting device 10 is installed in a show window 301 which is one of the buildings. The illumination device 10 includes a plurality of lamps 20 , a plurality of optical fibers 30 and a light source device 40 .

The plurality of lamps 20 are attached to different locations on the ceiling of the show window 301 and function as spotlights that illuminate the mannequins 303 . A light source device 40 is provided outside the show window 301 . A laser beam L10 (see FIG. 4) emitted from the light source device 40 is transmitted to each lamp 20 through an optical fiber 30 wired outside the show window 301. As shown in FIG.

The light source device 40 is a device that generates a laser beam L<b>10 containing blue light and supplies the laser beam L<b>10 to the plurality of lamps 20 using the optical fiber 30 . Specifically, for example, the light source device 40 includes a plurality of laser light sources 41 (see FIG. 2, etc.) made up of semiconductor laser elements that emit laser light L10 including blue light. By arranging the plurality of laser light sources 41 in one place in this manner, the laser light sources 41 can be arranged in a concentrated manner, and installation adjustment and maintenance can be easily performed.

The lamp 20 is a device that emits white light using the laser light L10 transmitted from the optical fiber 30 as an excitation light source.

Next, each part of the lighting device 10 will be described in detail. FIG. 2 is a schematic diagram showing the optical configuration of the illumination device 10 according to the embodiment. Note that FIG. 2 shows a set of lamps 20 and optical fibers 30 . In FIG. 2, the optical path L1 of the laser light L10 from the laser light source 41 to the lamp 20 is indicated by a solid line, and the optical path L2 of the return light from the lamp 20 is indicated by a chain double-dashed line. 2, the internal structure of the light source device 40 includes a laser light source 41 corresponding to a set of lamps 20 and an optical fiber 30, a light receiving section 42, and an optical system 50 for the laser light source 41 and the light receiving section 42. Illustrated. In other words, actually, a plurality of sets of the laser light source 41 , the light receiving section 42 and the optical system 50 are provided in the light source device 40 so as to correspond to each set of the lamp 20 and the optical fiber 30 . Since the laser light source 41, light receiving section 42 and optical system 50 of each set have basically the same configuration, only one set of laser light source 41, light receiving section 42 and optical system 50 will be described below. In addition, the light source device 40 is provided with a control section 49 (see FIG. 4) that collectively controls the laser light source 41 and the light receiving section 42 of each set.

First, the optical configuration of the light source device 40 will be described. A light source device 40 is provided with a laser light source 41 composed of a semiconductor laser element. The laser light source 41 can also be said to be a semiconductor laser light source. FIG. 3 is a graph showing light emission characteristics of a semiconductor laser element that is the laser light source 41 according to the embodiment. As shown in FIG. 3, the semiconductor laser element has, as its characteristics, a first emission mode that emits laser light L10 and a second emission mode that emits only LED light L20 (see FIG. 4) having an emission intensity lower than that of laser light L10. The mode is switched by the supplied current. The laser light L10 is an example of first light, and the LED light L20 is an example of second light. FIG. 3 illustrates a case where the first emission mode and the second emission mode are switched at the current value I1 of the current supplied to the semiconductor laser element. That is, the laser light source 41 emits light switchably between the laser light L10 and the LED light L20. Therefore, the LED light L20 also travels along the optical path L1 similar to that of the laser light L10.

As shown in FIG. 2, the optical system 50 includes a collimator lens 51, an aperture member 52, a dichroic mirror 53, a first condenser lens 54, and a second condenser lens .

The collimating lens 51 is a lens that converts the laser light L10 or the LED light L20 emitted from the laser light source 41 into parallel light. The collimating lens 51 is arranged on the optical axis of the laser light source 41 and on the downstream side in the direction of light emission. Although the collimator lens 51 is separate from the laser light source 41 here, the collimator lens and the laser light source may be integrated.

The diaphragm member 52 is an optical member that transmits the laser light L10 out of the light emitted from the laser light source 41 and transmitted through the collimating lens 51 and blocks part of the LED light L20. FIG. 4 is an enlarged view showing the positional relationship between the diaphragm member 52 according to the embodiment and the laser light L10 and the LED light L20. FIG. 5 is a plan view showing a schematic configuration of the diaphragm member 52 according to the embodiment. In FIG. 4, the diaphragm member 52 is shown in cross section, the laser light L10 is indicated by dark dot hatching, and the LED light L20 is indicated by light dot hatching.

As shown in FIGS. 4 and 5, the diaphragm member 52 is a plate-like member and has an opening 521 formed substantially in the center thereof. The aperture member 52 is made of a light shielding member such as a metal plate. The opening 521 is a rectangular opening elongated in the Y-axis direction. The opening 521 forms a path through which the laser light L10 or the LED light L20 emitted from the laser light source 41 passes. Since the laser light L10 has high directivity, the light distribution (angular distribution) of the light emitted from the light emitting point is relatively small, whereas the LED light L20 has low directivity and has a Lambertian light distribution. Due to the difference in light distribution characteristics between the two, a difference in spatial intensity distribution occurs at the aperture 521 of the diaphragm member 52 .

Here, the Y-axis direction corresponds to the fast axis of the laser light source 41 , the X-axis direction corresponds to the slow axis of the laser light source 41 , and the Z-axis direction corresponds to the optical axis of the laser light source 41 . Also, the center of the laser light source 41 in plan view (viewed in the Z-axis direction) substantially coincides with the center of the opening 521 . "Substantially match" includes not only perfect match but also an error of about several percent. The opening 521 has a shape in which the length in the fast axis direction is smaller than the length in the slow axis direction. The semiconductor laser element forming the laser light source 41 has a characteristic that the light emission pattern P when viewed in the optical axis direction tends to spread in the fast axis direction rather than in the slow axis direction. If the opening 521 has a shape in which the length in the fast axis direction is smaller than the length in the slow axis direction, the light from the semiconductor laser element having the above characteristics can pass efficiently.

As shown in FIG. 4, the irradiation range (first irradiation range) of the laser light L10 is included in the center of the irradiation range (second irradiation range) of the LED light L20. That is, the second irradiation range has a portion that overlaps with the first irradiation range and a portion that does not overlap. The opening 521 is formed to have a size that approximately matches the irradiation range (first irradiation range) after the laser beam L10 is collimated by the collimator lens 51 . Therefore, the laser light L10 generally passes through the opening 521, and the light overlapping the first irradiation range of the LED light L20 generally passes through the opening 521 as well. On the other hand, the light that does not overlap the first irradiation range in the LED light L20 is blocked by the aperture member 52 .

Although the opening 521 is rectangular in this embodiment, the shape of the opening 521 is not limited to this. Other shapes of the opening 521 include, for example, an elliptical shape, an oval shape, and a polygonal shape other than a rectangle. Further, the diaphragm member 52 may be made of a light-absorbing material in order to suppress scattering of light.

The dichroic mirror 53 is a first dichroic mirror that reflects light that has passed through the aperture member 52 and transmits return light. Specifically, the dichroic mirror 53 reflects light in the blue wavelength band from 440 nm to 470 nm and transmits light in the wavelength band greater than 470 nm. The dichroic mirror 53 is arranged on the optical axis of the laser light source 41 and downstream of the diaphragm member 52 . The laser light L10 or LED light L20 that has passed through the aperture member 52 is reflected by the dichroic mirror 53 to irradiate the first condenser lens 54 . Further, the returned light passes through the dichroic mirror 53 and is irradiated toward the light receiving section 42 . That is, on the side of the lamp 20 from the dichroic mirror 53, the optical path L1 of the laser light or LED light and the optical path L2 of the return light are shared, and are branched on the opposite side of the dichroic mirror 53.

The first condenser lens 54 is a lens that condenses the light reflected by the dichroic mirror 53 and makes it incident on one end face of the optical fiber 30 . The first condenser lens 54 is arranged between the dichroic mirror 53 and one end surface of the optical fiber 30 . The first condenser lens 54 also has the function of collimating the return light emitted from one end surface of the optical fiber 30 .

The second condenser lens 56 is a lens that condenses the return light that has passed through the dichroic mirror 53 and makes it enter the light receiving section 42 . The second condenser lens 56 is arranged between the dichroic mirror 53 and the light receiving section 42 on the optical path L2 of the return light.

The light-receiving unit 42 is a light-receiving element that receives return light and converts it into an electric signal. The light-receiving unit 42 photoelectrically converts the received return light to generate an electric signal corresponding to the amount of received light (that is, the intensity) of the return light. The generated electrical signal is output to the control section 49 . The light receiving unit 42 is, for example, a photodiode, but is not limited to this. For example, the light receiving section 42 may be a phototransistor or an image sensor.

Next, the optical configuration of the lamp 20 will be described. FIG. 2 illustrates the wavelength conversion element 21 and the optical member 22 as the internal structure of the lamp 20 .

The wavelength conversion element 21 is an element that converts the laser light L10 or the LED light L20 emitted from the other end surface of the optical fiber 30 into illumination light of a different wavelength band. Specifically, the wavelength conversion element 21 is arranged between the other end surface of the optical fiber 30 and the optical member 22 , and arranged to face the other end surface of the optical fiber 30 . The wavelength conversion element 21 has a substrate 211 and a fluorescent portion 212 . The substrate 211 is a plate that holds the fluorescent portion 212 . The substrate 211 is made of translucent material such as glass or sapphire. A fluorescent portion 212 is laminated on the main surface of the substrate 211 on the side of the optical member 22 .

The fluorescent portion 212 includes, in a dispersed state, a plurality of fluorescent particles that are excited by the laser light L10 or the LED light L20 emitted from the other end face of the optical fiber 30 and emit fluorescence. Upon irradiation, the phosphor emits fluorescence. Specifically, the fluorescent portion 212 can be exemplified by a base material made of transparent resin or glass in which fluorescent particles are dispersed, or by hardening fluorescent particles. In this embodiment, the fluorescent portion 212 emits white light. That is, the fluorescent part 212 converts the laser light L10 or the LED light L20 into illumination light with a longer wavelength band. For example, the fluorescent portion 212 contains two types of phosphors, a first phosphor that emits red light and a second phosphor that emits green light, in an appropriate ratio when irradiated with the laser light L10 or the LED light L20. The red light emitted from the first phosphor, the green light emitted from the second phosphor, and the blue light formed by the laser light L10 or the LED light L20 are mixed to emit white illumination light from the phosphor section 212. emitted.

Although the type and characteristics of the phosphor are not particularly limited, it is preferable that the phosphor has high heat resistance and does not cause luminance saturation because the laser beam L10 of relatively high output serves as the excitation light. For example, a yttrium-aluminum-garnet (YAG)-based phosphor is employed. The type of substrate that holds the phosphors in a dispersed state is not particularly limited, but the higher the transparency, the higher the white light emission efficiency. In addition, since the laser beam L10 having a relatively high output is incident thereon, a material having high heat resistance is preferable.

Most of the illumination light emitted from the wavelength conversion element 21 is radiated toward the optical member 22 , but part of it enters the optical fiber 30 from the other end surface of the optical fiber 30 as return light. This return light reaches the light receiving section 42 by passing through the optical path L2 shown in FIG.

The optical member 22 is an optical member for controlling the light distribution of the illumination light emitted by the wavelength conversion element 21 . Examples of the optical member 22 include a diffusing member that diffuses the illumination light and a condensing member that converges the illumination light. Examples of the diffusing member include a milky-white translucent member and a diffusing lens. A condensing lens etc. are mentioned as a condensing member. Further, the optical member 22 may have a function of an external light cut filter that removes external light entering the lamp 20 . In this case, it becomes difficult for external light to enter the optical fiber 30, and it is possible to suppress the external light from being included in the returned light. Examples of external light include sunlight and illumination light emitted from an illumination device other than the illumination device 10 . Depending on the situation of the place where the lamp 20 is installed, an outside light cut filter suitable for outside light at the place where the lamp 20 is installed may be adopted. Also, the external light cut filter may be separate from the optical member 22 .

Next, the control configuration of the lighting device 10 will be described. FIG. 6 is a block diagram showing the control configuration of lighting device 10 according to the embodiment. As shown in FIG. 6, the illumination device 10 includes a controller 49 electrically connected to each of the laser light sources 41 and the light receivers 42 of each set. The control unit 49 is composed of a drive circuit and a microcontroller. Specifically, the control unit 49 controls the laser light source 41 based on the electrical signal that is input from the light receiving unit 42 and caused by the return light. The control unit 49 has a nonvolatile memory storing a control program, a volatile memory serving as a temporary storage area for executing the program, an input/output port, a processor executing the program, and the like.

The controller 49 is connected to an external power source (not shown), and controls lighting of each laser light source 41 by controlling the current supplied to each laser light source 41 . For example, the control unit 49 controls the supply current to the laser light source 41 to select a first light emission mode that emits the laser light L10 and a second light emission mode that emits only the LED light L20 having an emission intensity lower than that of the laser light L10. This is an example of a switching unit that switches between. Also, the control unit 49 is an example of a disconnection detection unit that detects disconnection of the optical fiber 30 based on the detection result of the light receiving unit 42 . Specifically, the control unit 49 determines disconnection of the optical fiber 30 for each set.

For example, in a normal state where the optical fiber 30 is not disconnected, when the laser light source 41 is turned on, the laser light L10 or the LED light L20 passes through the optical fiber 30, and the return light also passes through the optical fiber 30. The light receiving section 42 outputs an electrical signal caused by the returned light to the control section 49 . In other words, when the control unit 49 receives an electrical signal from the light receiving unit 42, it determines that the optical fiber 30 in the same set as the light receiving unit 42 is normal. Based on this determination, the control unit 49 permits the light emission of the laser light source 41 of the same set as the light receiving unit 42 .

On the other hand, in an abnormal state where the optical fiber 30 is disconnected, when the laser light source 41 is turned on, the laser light L10 or the LED light L20 cannot pass through the optical fiber 30, so no return light is generated, and the light receiving unit 42 No electric signal is output to the control unit 49 . That is, when the control unit 49 does not receive an electrical signal from the light receiving unit 42, it determines that the optical fiber 30 in the same set as the light receiving unit 42 is broken. Based on this determination, the control unit 49 prohibits the laser light source 41 of the same set as the light receiving unit 42 from emitting light. After prohibition, the controller 49 does not turn on the laser light source 41 . Here, the controller 49 may prohibit only light emission in the first mode of the laser light source 41 and allow light emission in the first mode.

In an abnormal state, the light receiving section 42 may output an electric signal to the control section 49 due to a slight amount of scattered light or stray light within the light source device 40 . Therefore, the control section 49 may determine that the optical fiber 30 is broken even when an electrical signal significantly smaller than the electrical signal in the normal state is input from the light receiving section 42 .

In this way, when it is determined that the optical fiber 30 is disconnected, the light emission of the laser light source 41 is prohibited, but the laser light source 41 is temporarily turned on at the time of the determination. By the way, during installation or maintenance of the lighting device 10 , there is a possibility that an operator may be visually recognizing the cut portion of the optical fiber 30 . In this state, if the laser light source 41 temporarily emits the laser beam L10 to determine whether the wire is broken, the laser beam L10 is emitted from the wire breakage location, which may endanger the operator. . In order to prevent this, when the power is turned on, the controller 49 controls the supply current to the laser light source 41 to cause the laser light source 41 to emit light in the second emission mode. That is, when the power is turned on, the disconnection of the optical fiber 30 is detected by the LED light L20 emitted from the laser light source 41, thereby preventing the worker from being exposed to the laser light L10. Further, when the disconnection of the optical fiber 30 is not detected, the control unit 49 switches from the second emission mode to the first emission mode after a predetermined time has elapsed.

It is conceivable that the optical fiber 30 may be disconnected even when the laser light source 41 emits the laser beam L10 in the first emission mode in normal operation. In this case, the control unit 49 A disconnection of the optical fiber 30 is determined based on the laser beam L10. That is, in this case, the control unit 49 determines whether the wire is broken while remaining in the first light emission mode.

Here, the LED light L20 is susceptible to noise because it has a lower emission intensity than the laser light L10. In order to suppress the influence of noise and improve the detection accuracy of disconnection even with LED light, the diaphragm member 52 is provided in the present embodiment. The noise reduction effect of the diaphragm member 52 will be described below.

FIG. 7A is an explanatory diagram showing the progress of the LED light L20 in the illumination device 10 according to the embodiment. FIG. 7B is an explanatory diagram showing the progress of the LED light L21 in the lighting device according to the comparative example. The lighting device according to the comparative example differs from the lighting device 10 according to the embodiment in that the aperture member 52 is removed, and the rest of the configuration is the same as that of the lighting device 10 according to the embodiment.

As shown in FIG. 7B, most of the LED light L21 is reflected by the dichroic mirror 53 and travels toward the optical fiber 30. As shown in FIG. However, the light out of the dichroic mirror 53 out of the LED light L21 passes through the dichroic mirror 53 and can become the light L22 scattered within the light source device 40 . The light L<b>22 may be scattered within the light source device 40 and enter the light receiving section 42 . In addition, the light of the LED light L21 that hits the end face of the dichroic mirror 53 is reflected by the end face and can become the light L23 that enters the light receiving section 42 via the second condenser lens 56 . In this way, the lights L22 and L23 may become noise light to the light receiving section 42 and adversely affect the detection result of the light receiving section 42 .

On the other hand, as shown in FIG. 7A , in the illumination device 10 according to the embodiment, the diaphragm member 52 blocks light that does not overlap the first irradiation range among the LED light L20. As a result, all of the LED light L20 that has passed through the opening 521 of the diaphragm member 52 is reflected by the main surface of the dichroic mirror 53 and travels toward the optical fiber 30 . That is, the lights L22 and L23 exemplified in the comparative example are not generated in the illumination device 10 according to the embodiment. Therefore, it is possible to suppress noise light entering the light receiving section 42, and as a result, the detection accuracy of disconnection is improved.

FIG. 8A is an actual measurement image showing the emission intensity profile of the LED light L20 between the diaphragm member 52 and the dichroic mirror 53 according to the embodiment. FIG. 8B is an actual measurement image showing the emission intensity profile of the LED light L21 between the collimating lens 51 and the dichroic mirror 53 according to the comparative example. The emission intensity profile of the LED light L20 shown in FIG. 8A and the emission intensity profile of the LED light L21 shown in FIG. 8B are detected at the first detection point S1 in FIG. 2, for example. In addition, in FIGS. 8A and 8B, the intensity of light emission intensity is represented by shading. Specifically, the darker the gradation, the lower the luminous intensity, and the lighter the luminous intensity, the higher the luminous intensity. 8A and 8B, lines L2y and L3y indicate the emission intensity distribution on a line (first center line C1) parallel to the Y-axis direction passing through the center of the image in the X-axis direction. Lines L2x and L3x indicate the light emission intensity distribution on a line (second center line C2) parallel to the X-axis direction passing through the center in the Y-axis direction. Here, it is assumed that there is a point with the highest emission intensity in the image on the first center line C1, and there is also a point with the highest emission intensity in the image on the second center line C2.

As can be seen from FIGS. 8A and 8B, the LED light L20 according to the embodiment is narrowed by the diaphragm member 52 more than the LED light L21 according to the comparative example. In particular, the aperture of the LED light L20 is conspicuous in the X-axis direction.

FIG. 9 is a graph showing the emission intensity distribution of the LED light L20 according to the embodiment and the emission intensity distribution L3x of the LED light L21 according to the comparative example superimposed. Comparing the emission intensity distributions L2x and L3x as shown in FIG. 9, it can be seen that light outside the first irradiation range is cut in the LED light L20 according to the embodiment. As described above, it has been demonstrated that light outside the first irradiation range is cut by the aperture member 52 even in the actual illumination device 10 .

Next, the assembly process of the lighting device 10 will be described. In the illumination device 10, it is necessary to reliably irradiate the one end face of the optical fiber 30 with the laser light L10. Therefore, it is desirable to accurately position the one end face of the optical fiber 30 and the optical path L1 of the laser light L10. be However, if the one end surface of the optical fiber 30 is positioned while the laser beam L10 having a high emission intensity is irradiated, if the positional relationship between the laser light source 41 and the optical fiber 30 is deviated, the one end surface of the optical fiber 30 may be misaligned during the positioning operation. The laser beam L10 may hit the edge or the like, and the optical fiber 30 may be damaged. Further, positioning may be performed while confirming the irradiation position of the laser beam L10 by visual observation or image recognition of one end surface of the optical fiber 30 . In that case, the laser beam L10 may also scatter at one end surface of the optical fiber 30 and affect the human body or the camera. For this reason, positioning with respect to the one end face of the optical fiber 30 using the LED light L20 with a weak emission intensity is considered.

FIG. 10A is a schematic diagram showing an emission intensity profile of LED light L20 with respect to one end face of optical fiber 30 according to the embodiment. FIG. 10B is a schematic diagram showing the emission intensity profile of the LED light L21 with respect to one end surface of the optical fiber 30 according to the comparative example. In addition, in FIG. 10A and FIG. 10B, the strength and weakness of the emitted light intensity are represented by shading. Specifically, the darker the gradation, the higher the luminous intensity, and the lighter the luminous intensity, the lower the luminous intensity. That is, the relationship is opposite to that shown in FIGS. 8A and 8B. 10A and 10B, the core outer diameter at one end surface of the optical fiber 30 is indicated by a solid line L30. Since the incident end face position of the optical fiber 30 is adjusted to have a substantially conjugate relationship with the light emitting point of the laser light source 41, the light emission intensity profiles shown in FIGS. The shape reflects the intensity profile. Therefore, at the light emission point of the laser light source 41 with high emission intensity, the emission intensity profile has a shape extending in the X-axis direction, which is the slow axis direction.

As shown in FIGS. 10A and 10B , both the LED light L20 according to the embodiment and the LED light L21 according to the comparative example are within the second irradiation range, the first irradiation range overlapping the laser light L10. has the highest emission intensity. However, as shown in FIG. 10B, in the LED light L21 according to the comparative example, since there is no diaphragm by the diaphragm member 52, the emission intensity difference between the first irradiation range and other areas is not large, and the outer shape of the first irradiation range becomes vague. Therefore, it becomes difficult to accurately detect the first irradiation range visually or by image recognition, which is a factor in lowering the reliability of the positioning work. On the other hand, as shown in FIG. 10A, the LED light L20 according to the embodiment is narrowed by the diaphragm member 52, so that the emission intensity can be sharply changed at the boundary between the first irradiation range and other areas. As a result, the outer shape of the first irradiation range becomes clearer than in the comparative example. Therefore, the first irradiation range can be accurately detected visually or by image recognition, and the reliability of the positioning work can be enhanced.

FIG. 11A is an actual measurement image showing the emission intensity profile of the LED light L20 with respect to one end surface of the optical fiber 30 according to the embodiment. FIG. 11B is an actual measurement image showing the emission intensity profile of the LED light L21 with respect to one end surface of the optical fiber 30 according to the comparative example. The emission intensity profile of the LED light L20 shown in FIG. 11A and the emission intensity profile of the LED light L21 shown in FIG. 11B are detected, for example, at the second detection point S2 (incidence end face of the optical fiber 30) in FIG. In addition, in FIGS. 11A and 11B, the intensity of the emission intensity is represented by shading. Specifically, the darker the gradation, the lower the luminous intensity, and the lighter the luminous intensity, the higher the luminous intensity. 11A and 11B, lines L4y and L5y indicate the emission intensity distribution on the first center line C1, and lines L4x and L5x indicate the emission intensity distribution on the second center line C2. . Here, the point with the highest luminous intensity in the image is on the first center line C1, and the point with the highest luminous intensity in the image is on the imaginary line C3 parallel to the second center line C2. and

As can be seen from FIGS. 11A and 11B, the LED light L20 according to the embodiment is narrowed by the diaphragm member 52 more than the LED light L21 according to the comparative example. Also in this case, the aperture of the LED light L20 is conspicuous in the X-axis direction.

FIG. 12 is a graph showing an emission intensity distribution L6x of the LED light L20 according to the embodiment and an emission intensity distribution L7x of the LED light L21 according to the comparative example. The emission intensity distribution L6x of the LED light L20 indicates the emission intensity distribution on the imaginary line C3, and the emission intensity distribution L7x of the LED light L21 indicates the emission intensity distribution on the imaginary line C3. As shown in FIG. 12, when the emission intensity distributions L6x and L7x are compared, it can be seen that light outside the first irradiation range is cut in the LED light L20 according to the embodiment. As a result, the emission intensity can be sharply changed at the boundary between the first irradiation range and other regions. As described above, it has been demonstrated that light outside the first irradiation range is cut by the aperture member 52 even in the actual illumination device 10 .

[Effects, etc.]
As described above, the illumination device 10 according to the present embodiment controls the laser light source 41 and the current supplied to the laser light source 41, so that the first light emission mode for emitting the laser light L10 (first light) and the laser A control unit 49 (switching unit) that switches between a second light emission mode that emits LED light (second light) having an emission intensity lower than that of the light L10, and guides the laser light L10 or the LED light L20 emitted by the laser light source 41. An optical fiber 30 and an aperture member 52 disposed between the laser light source 41 and the optical fiber 30, the aperture member 52 transmitting the laser light L10 emitted from the laser light source 41 in the first emission mode, It has an opening 521 that blocks light that does not overlap the first irradiation range (irradiation range) of the laser light L10, out of the LED light L20 irradiated from the laser light source 41 in the second light emission mode.

According to this, the opening 521 of the diaphragm member 52 transmits the laser light L10 and blocks light that does not overlap the first irradiation range of the laser light L10 among the LED light L20. Light outside the irradiation range is cut by the aperture member 52 . As a result, the emission intensity can be sharply changed at the boundary between the first irradiation range and other regions of the LED light L20. As a result, the outline of the first irradiation range can be clarified, and the first irradiation range can be accurately detected visually or through image recognition. Therefore, the reliability of the positioning work can be enhanced.

The illumination device 10 also includes a first condenser lens 54 (condensing lens) for condensing the laser light L10 or the LED light L20 emitted by the laser light source 41 onto the optical fiber 30. It is arranged between the light source 41 and the first condenser lens 54 .

According to this, since the diaphragm member 52 is arranged between the laser light source 41 and the first condenser lens 54 , the LED light L 20 is focused by the diaphragm member 52 before being condensed by the first condenser lens 54 . can be squeezed. After condensing, the light outside the first irradiation range is also difficult to cut because the area is small, but before condensing, the light outside the first irradiation range remains large in area, so it is cut by the aperture member 52. It's easy to do. Thereby, the light outside the first irradiation range in the LED light L<b>20 can be reliably cut by the diaphragm member 52 .

The illumination device 10 also includes a wavelength conversion element 21 that converts the laser light L10 or the LED light L20 guided by the optical fiber 30 into illumination light in a different wavelength band, and a part of the illumination light, the laser light L10. Alternatively, the light receiving unit 42 receives return light guided by the optical fiber 30 in the opposite direction to the LED light L20, and the control unit 49 (disconnection detection unit).

According to this, since the control unit 49 detects disconnection of the optical fiber 30 based on the detection result of the light receiving unit 42, it is possible to detect disconnection of the optical fiber 30 caused by the return light. In particular, since noise light that may enter the light receiving section 42 is cut from the LED light L20 by the aperture member 52, it is possible to improve the detection accuracy of disconnection. Here, as an example of conventional disconnection detection, there is a method of detecting disconnection of an optical fiber by storing an electric wire along with an optical fiber in a fiber cable and detecting the disconnection of the electric wire. However, since it cannot be said that the electric wire is surely disconnected when the optical fiber is disconnected, there is a problem in detection accuracy. On the other hand, in the method according to the present embodiment, when the optical fiber 30 is broken, the return light is surely not transmitted, so the accuracy of detecting the breakage can be improved.

As another example of conventional disconnection detection, there is a method in which a light receiving unit is incorporated in a lamp instead of in the light source device. However, since the lamp requires energization, there is a problem that the reliability of the lamp, which is used in a harsh environment, tends to decrease. In the method according to the present embodiment, disconnection of the optical fiber 30 can be detected without energizing the lamp 20, so a highly reliable lamp 20 can be realized.

Further, when the control unit 49 detects disconnection of the optical fiber 30, the control unit 49 prohibits the laser light source 41 from emitting light in the first mode.

According to this, when the disconnection of the optical fiber 30 is detected, the controller 49 prohibits the laser light source 41 from emitting light in the first mode, so that the laser light can be prevented from leaking from the disconnection point. Therefore, the lighting device 10 with high safety can be provided. The opening 521 has a shape in which the length of the laser light source 41 in the fast axis direction is longer than the length of the laser light source 41 in the slow axis direction.

According to this, the shape of the opening 521 is such that the length in the fast axis direction is smaller than the length in the slow axis direction. Therefore, the light from the semiconductor laser element having the property that the light emission pattern P when viewed in the optical axis direction tends to spread in the fast axis direction rather than in the slow axis direction can be efficiently passed through the opening 521 .

[Modification]
Next, a modified example according to this embodiment will be described. FIG. 13 is a schematic diagram showing an optical configuration of a lighting device 10B according to a modification. It should be noted that, in the following description, the same reference numerals may be assigned to the same parts as in the above-described embodiment, and the description thereof may be omitted.

As shown in FIG. 13, the illumination device 10B according to the modification is different from the illumination device 10 according to the above embodiment in that light from a plurality of laser light sources 41b and 41c is incident on one optical fiber 30. different from Specifically, two laser light sources 41b and 41c are provided for one optical fiber 30 in the illumination device 10B. The optical system 50b of the illumination device 10B includes collimator lenses 51b and 51c and dichroic mirrors 53b and 53c corresponding to the laser light sources 41b and 41c, respectively. A diaphragm member 52b is provided in the optical system 50b. The diaphragm member 52b is arranged between the two collimator lenses 51b and 51c and the two dichroic mirrors 53b and 53c. The diaphragm member 52b has openings 521b and 521c corresponding to the laser light sources 41b and 41c, respectively. The laser light L10 emitted by the laser light source 41b passes through the opening 521b, and the light overlapped with the first irradiation range in the LED light L20 emitted by the laser light source 41b also passes through the opening 521b. In addition, the laser light L10 emitted by the laser light source 41c passes through the opening 521c, and the light overlapped with the first irradiation range in the LED light L20 emitted by the laser light source 41c also passes through the opening 521c. On the other hand, light that does not overlap the first irradiation range in the LED light L20 emitted by the laser light sources 41b and 41c is blocked by the aperture member 52b. That is, the noise light from each of the laser light sources 41b and 41c is suppressed by the diaphragm member 52b.

The laser light L10 or LED light L20 emitted from the laser light source 41b passes through the optical path L11 composed of the collimator lens 51b, the opening 521b, and the dichroic mirror 53b, and the first condenser lens 54 passes through the optical fiber 30. Incident on one end surface. On the other hand, the laser light L10 or the LED light L20 emitted from the laser light source 41c passes through the optical path L12 composed of the collimator lens 51c, the opening 521c and the dichroic mirror 53c, and passes through the optical fiber through the first condenser lens 54. Incident on one end surface of 30 . Also, the laser light L10 or the LED light L20 emitted from each of the laser light sources 41b and 41c is condensed by the first condensing lens 54 and travels through the optical fiber 30 along the same optical path L13. The laser light L10 or LED light L20 traveling along the optical path L13 is converted into illumination light by the wavelength conversion element 21 and emitted to the outside of the lamp 20 . Part of the illumination light passes through the optical path L2 and reaches the light receiving section 42 as return light.

By the way, when condensing the laser beams L10 from the plurality of laser light sources 41b and 41c and introducing them into one optical fiber 30, the distance between the optical axes of the laser beams L10 from the laser light sources 42b and 42c is narrowed. In addition, it is desirable to dispose the dichroic mirrors 53b and 53c as close as possible. From this point of view, it is conceivable to use the small dichroic mirrors 53b and 53c. and noise light is likely to occur. However, as described above, if the diaphragm member 52b having the openings 521b and 521c corresponding to the laser light sources 41b and 41c is provided, the light in the second irradiation range of the LED light L20 is cut. Therefore, it becomes difficult for the ends of the dichroic mirrors 53b and 53c to be arranged within the second irradiation range of the LED light L20. Therefore, the generation of noise light can also be suppressed.

In this way, when condensing a plurality of laser light sources 42b and 42c and introducing them into one optical fiber 30, a diaphragm member 52b having openings 521b and 521c corresponding to the respective laser light sources 41b and 41c is adopted. It is preferable to

Although the case where one diaphragm member 52b has two openings 521b and 521c is illustrated here, a plurality of diaphragm members each having one opening may be installed so as to correspond to each laser light source. may

[others]
As described above, the illumination device according to the present invention has been described based on the above-described embodiment and modifications, but the present invention is not limited to the above-described embodiment and modifications.

In the illumination device 10 according to the above-described embodiment, the case where the single optical fiber 30 guides the laser light, the LED light, and the return light is exemplified. However, the illumination device may be provided with a first optical fiber for laser light and LED light and a second optical fiber for return light. In this case, the first optical fiber and the second optical fiber should be integrated as one transmission cable. This makes it possible to detect disconnection of the transmission cable (disconnection of one of the first optical fiber and the second optical fiber). Also, the first optical fiber and the second optical fiber can divide the optical path of the laser light and the LED light and the optical path of the return light. Therefore, the dichroic mirror 53 is not required, and the number of parts can be reduced.

Further, an optical member may be arranged between the wavelength conversion element 21 and the other end face of the optical fiber 30 in the lamp 20 for condensing the returned light. Thereby, the emission intensity of the return light entering the optical fiber 30 can be increased. Examples of optical members for condensing the returned light include condensing lenses and light pipes.

Moreover, in the above-described embodiment, the case where the illumination device 10 illuminates the inside of the show window 301 has been exemplified. However, since the lamp 20 of the lighting device 10 is not provided with an electrical component, it is also possible to arrange the lamp 20 underwater and use it as an underwater illumination.

In addition, a form obtained by applying various modifications to the embodiment that a person skilled in the art can think of, and a form realized by arbitrarily combining the constituent elements and functions of each embodiment within the scope of the present invention. is also included in the present invention.

10, 10B lighting device 21 wavelength conversion element 30 optical fiber 40 light source device 41, 41b, 41c laser light source (semiconductor laser light source)
42 light receiving unit 49 control unit (switching unit, disconnection detection unit)
52, 52b diaphragm member 54 first condenser lens (condenser lens)
521, 521b, 521c opening L10 laser light L20, L21 LED light

Claims (5)

a semiconductor laser light source;
a switching unit that switches between a first light emission mode that emits a first light and a second light emission mode that emits a second light having an emission intensity lower than that of the first light, by controlling a supply current to the semiconductor laser light source;
an optical fiber that guides the first light or the second light emitted by the semiconductor laser light source;
A diaphragm member arranged between the semiconductor laser light source and the optical fiber,
The aperture member transmits the first light emitted from the semiconductor laser light source in the first light emission mode, and transmits the second light emitted from the semiconductor laser light source in the second light emission mode. A lighting device having an opening that blocks light that does not overlap with the irradiation range of one light. comprising a condenser lens for condensing the first light or the second light emitted by the semiconductor laser light source onto the optical fiber;
The illumination device according to claim 1, wherein the diaphragm member is arranged between the semiconductor laser light source and the condenser lens. a wavelength conversion element that converts the first light or the second light guided by the optical fiber into illumination light in a different wavelength band;
a light receiving unit that receives return light that is part of the illumination light and is guided by the optical fiber in a direction opposite to the first light or the second light;
The lighting device according to claim 1 or 2, further comprising a disconnection detection unit that detects disconnection of the optical fiber based on a detection result of the light receiving unit. 4. The lighting device according to claim 3 , wherein the disconnection detector prohibits the semiconductor laser light source from emitting light in the first light emission mode when detecting disconnection of the optical fiber. The illumination device according to any one of claims 1 to 4, wherein the opening has a shape in which the length in the fast axis direction of the semiconductor laser light source is longer than the length in the slow axis direction of the semiconductor laser light source.

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