JP7595074B2 - Position indicator - Google Patents

Description

This invention relates to a position indicator having a pressure detection function and used together with a position detection device equipped with a position detection sensor.

Coordinate input devices consisting of a position detection device equipped with a position detection sensor and a position indicator that inputs instructions using a surface area whose position can be detected by the position detection sensor as a position indication input surface come in a variety of types, such as electromagnetic coupling types and electrostatic coupling types, depending on the coupling method used between the position detection sensor and the position indicator.

A pen-type position indicator used in this type of coordinate input device is generally configured to detect pressure (writing pressure) applied to the tip (pen tip) of the core and transmit it to a position detection device. In this case, in order to detect the pressure applied to the core, the tip of the core is protruded from an opening in the housing of the position indicator, and the core is made movable in its axial direction relative to the housing. A pressure detection unit is provided on the opposite side of the tip of the core, and this pressure detection unit is configured to detect the axial displacement of the core corresponding to the pressure applied to the tip as an electrical change such as a change in capacitance, a change in inductance value, or a change in resistance.

Pressure detection units that detect pressure as a change in capacitance include those in which the capacitance changes as the contact area between a dielectric and a conductive elastic member changes in response to the applied pressure (see, for example, Patent Document 1 (JP Patent Publication No. 2016-126503)), and those consisting of a semiconductor device in which the distance between two electrodes facing each other via a dielectric air layer changes in response to the applied pressure (see, for example, Patent Document 2 (JP Patent Publication No. 2013-161307)).

There is also a known pressure detection unit that detects the axial displacement of the core in response to the applied pressure as a change in inductance value (see, for example, Patent Document 3 (e.g., JP 2017-216002 A)). Furthermore, there is also a known pressure detection unit that uses a strain gauge to detect the axial displacement of the core in response to the applied pressure as a change in resistance value (see, for example, Patent Document 4 (JP 2019-016038 A)).

In the position indicator, the tip of the core body is brought into contact with the input surface of the position detection sensor, and the tip of the core body of the position indicator is pressed against the input surface, thereby applying pressure to the tip of the core body. The pressure detection unit detects the pressure applied to the tip of the core body. In the coordinate input device, the position detection device receives information corresponding to the pressure detected by the pressure detection unit of the position indicator, and outputs it as information on the pen pressure value applied to the tip of the core body of the position indicator.

JP 2016-126503 A JP 2013-161307 A JP 2017-216002 A JP 2019-016038 A

The pressure detection units in all of the above-mentioned Patent Documents 1 to 4 are constructed to directly detect the reaction force (pressure) generated when the tip of the core body of the position indicator is pressed against the input surface, causing the core body to displace in the axial direction, by converting the reaction force into a change in capacitance, a change in inductance value, or a change in resistance.

For this reason, it is necessary to design a structure in which the pressure applied to the tip of the core body is directly applied to the pressure detection section, resulting in a complex structure. In addition, because the pressure applied to the tip of the core body is directly applied to the pressure detection section, there is a problem that the components that make up the pressure detection section will be subjected to continuous pressure over many years of use, which can cause defects, and it is also necessary to provide a structure to protect the pressure detection section from impact loads, making the structure even more complex.

Furthermore, in the pressure detection units of Patent Documents 1 to 4 mentioned above, when a slight pressure is applied to the tip of the core body of the position indicator after the tip of the core body comes into contact with the input surface, the changes in capacitance, inductance, and resistance value according to the applied pressure are not stable, making it difficult to respond immediately and to correctly detect pressure.

For this reason, in order for the pressure detection unit to detect the pressure applied to the tip of the core of the position indicator, a certain amount of axial movement (stroke) of the core is required, and it is difficult to determine the pressure detection start point (the position at which the pressure applied to the tip becomes detectable and can be output after the tip of the core comes into contact with the input surface).

Therefore, in the pressure detection unit, the load at which the applied pressure can be detected is not 0 grams, but an offset load of a specified magnitude is set, and for loads below this offset load, the output pressure value of the pressure detection unit of the position indicator is output as zero and transmitted to the position detection device, but setting this offset load was extremely troublesome.

The object of this invention is to provide a position indicator and coordinate input device that can solve the above problems.

In order to solve the above problems,
A core body having a tip portion protruding from an opening of the housing and disposed so as to be displaceable in response to pressure applied to the tip portion;
an end surface that exhibits a displacement corresponding to the displacement of the core body;
a displacement detection unit that detects a displacement of the end surface in response to the pressure;
An electronic pen comprising:
the end surface is an end surface of a core body fitting member into which the end surface of the core body opposite to the tip portion is fitted and which displaces in response to displacement of the core body,
the displacement detection unit includes a light emitting unit and a light receiving unit, and is configured such that light emitted from the light emitting unit is projected onto the end face, and the light receiving unit receives light that is reflected from the end face and returns, and detects the displacement of the end face based on a phase difference between the light emitting light and the light receiving light;
The present invention provides a position indicator, characterized in that a pressure applied to the core body is detected based on the displacement detected by the displacement detection unit.

In the position indicator of the above configuration, the displacement detection unit emits emitted light from the light emitting unit to the end face that displaces in response to the displacement of the core applied to the tip, and the received light that is reflected from the end face and returned is received by the light receiving unit. The displacement detection unit then detects the displacement of the end face based on the phase difference between the emitted light and the received light. The position indicator detects the pressure applied to the tip of the core based on the displacement detected by this displacement detection unit.

1 is a diagram for explaining a configuration example of an electronic pen according to a first embodiment of a position indicator according to the present invention; 3 is a diagram showing an example of the configuration of a displacement detection unit mounted on an electronic pen of a first embodiment of a position indicator according to the present invention; FIG. 3 is a waveform diagram for explaining a configuration example of the displacement detection unit in FIG. 2 . 11A and 11B are diagrams for explaining a configuration example of an electronic pen as a second embodiment of a position indicator according to the present invention; 13A and 13B are diagrams for explaining functions of a displacement detection unit mounted on an electronic pen of a second embodiment of a position indicator according to the present invention. 13 is a diagram showing an example of the configuration of a displacement detection unit mounted on an electronic pen of a second embodiment of a position indicator according to the present invention; FIG.

Below, an embodiment of the position indicator of the present invention will be described with reference to the drawings.

[First embodiment]
The position indicator of the first embodiment is an example of an active capacitance type electronic pen having a pen-shaped housing. Fig. 1A is an enlarged cross-sectional view for explaining the configuration of the pen tip side of an electronic pen 1 as the position indicator of the first embodiment.

In this example of the electronic pen 1, a front cap 3 is attached to the tip end of a cylindrical housing 2 made of a conductive material, such as SUS (Steel Use Stainless).

The front cap 3 is made of an insulating material, such as resin, and is configured to have a hollow portion inside. In this example, the front cap 3 is integrally formed with a cylindrical portion 3a whose diameter is slightly smaller than the diameter of the inner wall surface of the housing 2, and a tapered portion 3b formed on one end side of the axial center of the cylindrical portion 3a, which is the pen tip side, so that the diameter becomes smaller as it approaches the pen tip.

The front cap 3 is attached to the pen tip side of the housing 2 by inserting and fitting the cylindrical portion 3a into the housing 2 and gluing it as necessary.

An opening 3c is provided at the tapered tip of the tapered portion 3b of the front cap 3, and an elastic member 4 made of, for example, elastic rubber is attached to this opening 3c. This elastic member 4 has an opening 4a with the same diameter as the opening 3c of the tapered portion 3b of the front cap 3.

In this example, the core body 5 is made of a conductive material, such as a conductive metal, and a cover 52 that covers the entire conductor core 51 except for the rear end 51a on the side opposite to the tip. The cover 52 is made of a hard resin, such as POM (Polyoxymethylene).

In this example, the core body 5 has a core body main body portion 5a that is inserted into the hollow portion of the housing 2 through the opening 4a of the elastic member 4 and the opening 3c of the front cap 3, and a tip portion 5b that protrudes to the outside from the opening 4a of the elastic member 4.

The core body 5a is covered with the resin of the cover 52, except for the rear end 51a of the conductor core 51. The outer diameter of the portion of the core body 5a covered with the resin of the cover 52 is smaller than the diameter of the opening 4a of the elastic member 4 and the opening 3c of the front cap 3.

The tip 5b is covered with the resin of the cover 52 so that the tip side of the conductor core 51 is not exposed to the outside. The diameter of the tip 5b at the connection part with the core body 5a is larger than the diameter of the opening 4a of the elastic member 4 and the opening 3c of the front cap 3, and the tip 5b is cone-shaped with a diameter that decreases toward the pen tip. A step with a ring-shaped end surface 5c is formed at the connection part of the tip 5b with the core body 5a.

In this example, as shown in Fig. 1(A), the diameter of the connecting portion of the tip portion 5b with the core body portion 5a is the same as the diameter of the tip side of the elastic member 4. As a result, as shown in Fig. 1, the outer peripheral side surface of the tip portion 5b of the core body 5 and the outer peripheral side surface of the elastic member 4 are flush with each other so that no step is created.

Since the core body 5 has the above-mentioned configuration, the core body main body 5 can be inserted into the hollow portion of the housing 2 through the opening 4a of the elastic member 4 and the opening 3c of the front cap 3. When the core body main body 5a of the core body 5 is inserted into the housing 2, the ring-shaped end surface 5c of the connecting portion of the tip 5b with the core body main body 5a comes into contact with the ring-shaped end surface 4b of the elastic member 4.

In this example, a displacement detection unit 6 that optically detects the axial displacement of the core body 5 and a core body fitting member 7 having an end face 7S that displaces in response to the axial displacement of the core body 5 are provided within the hollow portion of the front cap 3.

As shown in FIG. 2, in this example, the displacement detection unit 6 includes a light-emitting unit, for example a light-emitting diode 61 that emits laser light, a light-receiving unit, in this example a TOF (Time Of Flight) sensor including a 3D (3 Dimension) sensor 62 and a TOF controller 63, and also includes a pen pressure detection circuit 67, for example composed of a microprocessor.

The TOF controller 63 controls the light emission driver 64 to emit pulse-modulated laser light emission light Tp (see the waveform diagram in FIG. 3(A)) from a light emitting diode 61 constituting an example of a light emitting unit. The laser light emission light Tp emitted from the light emitting diode 61 is projected onto the end face 7S through a lens 65 in this example and reflected by the end face 7S. The laser light reflected by this end face 7S is received as received light Rp by a 3D sensor constituting an example of a light receiving unit through a lens 66, and the light reception result is supplied to the TOF controller 63.

At this time, the received light Rp is received by the 3D sensor 62 at a time delayed by a time corresponding to the distance between the displacement detection unit 6 and the end face 7S from the time of emission of the light from the light-emitting diode 61. Therefore, as shown in Fig. 3(B), the received light Rp has a phase difference PHd of the delay time corresponding to the distance between the displacement detection unit 6 and the end face 7S with respect to the emitted light Tp of the laser light of the emitted light shown in Fig. 3(A).

The TOF controller 63 detects the phase difference PHd between the emitted light Tp and the received light Rp, and supplies information on the detected phase difference PHd to a writing pressure detection circuit 67, which will be described later. The writing pressure detection circuit 67 detects the writing pressure applied to the tip 5b of the core 5 based on the information on the phase difference PHd from the TOF controller 63. The writing pressure detection circuit 67 supplies information on the detected writing pressure to a signal processing circuit 9 arranged on the printed circuit board 10, as will be described later. The writing pressure detection process in the writing pressure detection circuit 67 will be described in detail later.

Although not shown in Figure 1, the electronic pen 1 of this embodiment is equipped with a battery that supplies power supply voltage to drive the displacement detection unit 6 and the signal processing circuit 9.

In this example, the displacement detection unit 6 is held by the holder portion 8 near the center position of the axis of the electronic pen 1 with the laser light emitting portion and light receiving portion oriented perpendicular to the axis direction of the electronic pen 1, and is arranged in the hollow portion of the front cap 3.

In this case, as shown in FIG. 1(B), notch grooves 3d are provided at multiple positions in the circumferential direction on the open end side opposite the tip side of the front cap 3, which are formed in a hook shape from the open end. On the other hand, multiple protrusions 8a are formed in the holder part 8, which fit into each of the multiple notch grooves 3d. The holder part 8 is then pushed into the front cap 3 in the axial direction with the protrusions 8a fitted into the notch grooves 3d, and then rotated in the circumferential direction, so that the protrusions 8a engage with the hook-shaped notch grooves 3d, as shown in FIG. 3(B). This allows the holder part 8 to be connected to the front cap 3 so that it does not move in the axial direction. The holder part 8 and the front cap 3 may be connected and bonded together as shown in FIG. 1(B).

On the side of the holder 8 opposite to the side where it is joined to the front cap 3, a board mounting platform 8b is formed, and a printed circuit board 10 is mounted on this board mounting platform 8b. The aforementioned signal processing circuit 9 is disposed on this printed circuit board 10. In this example, the signal processing circuit 9 is composed of an IC (Integrated Circuit).

The signal processing circuit 9 generates a signal to be supplied to the conductor core portion 51 of the core body 5. In this embodiment, this signal includes a position detection signal and, as additional information of the position detection signal, writing pressure information detected by the writing pressure detection circuit 67 of the displacement detection unit 6.

The holder portion 8 is configured to hold the core body fitting member 7 within the hollow portion of the front cap 3, as well as to hold a shielding part (the conductor spring 12 described below) for shielding the conductor core portion 51 of the core body 5. The core body fitting member 7 and the shielding part are configured to be held in the holder portion 8 in advance, before the holder portion 8 is joined to the front cap 3, as described above.

That is, the holder portion 8 has a cylindrical portion 8c that forms a cylindrical space on the hollow portion side of the front cap 3. A cylindrical holding member 11 is inserted into and connected to this cylindrical portion 8c. The holding member 11 holds the core fitting member 7 in a state in which the end face 7S can move in the axial direction. The hollow portion 11a of this cylindrical holding member 11 forms a space for projecting the emitted light Tp from the displacement detection unit 6 onto the end face 7S and for receiving the reflected light from the end face 7S.

The core body fitting member 7 comprises a core body fitting member main body portion 71, a conductive member 72 which is joined to the core body 5 side of the core body fitting member main body portion 71, and an end face forming portion 73 which is joined to the displacement detection unit 6 side of the core body fitting member main body portion 71.

The core body fitting member main body 71 has, on the core body 5 side in the axial direction, a fitting recess 71a into which the rear end 51a of the conductor core 51 of the core body 5 is fitted, and, on the displacement detection section 6 side in the axial direction, a fitting protrusion 71b that fits into the end face forming portion 73, and a flange portion 71c that protrudes in a direction perpendicular to the axial direction.

The conductive member 72 is made of an elastic material such as conductive rubber, and has a through hole 72a that communicates with the fitting recess 71a of the core fitting member main body 71 when it is coupled to the core 5 side of the core fitting member main body 71. The diameter of the through hole 72a of the conductive member 72 is equal to the diameter of the rear end 51a of the conductor core 51 of the core 5, and the rear end 51a of the conductor core 51 of the core 5 is pressed into the through hole 72a of the conductive member 72 and then fitted into the fitting recess 71a of the core fitting member main body 71. The core 5 can be pulled out of the core fitting member 7 and replaced.

In this case, the conductor core 51 of the core body 5 and the conductive member 72 are in strong contact with each other due to the elastic force of the conductive member 72, and the two are electrically connected well. In this example, one end 12a of the coil spring 12 made of a conductive material, for example, a conductive metal, is connected to the conductive member 72. As shown in FIG. 1(A), the coil spring 12 is arranged in a state in which it is wound around the outer periphery of the holding member 11, and the other end 12b is configured to penetrate the holder part 8 and be led out to the printed circuit board 10 side, and to be electrically connected to the signal processing circuit 9 on the printed circuit board 10. In the example of FIG. 1(A), the other end 12b of the coil spring 12 is configured to be electrically connected to the signal processing circuit 9 on the front side from the back side of the printed circuit board 10 via a through hole.

The position detection signal and a signal containing writing pressure information generated by the signal processing circuit 9 are supplied to the conductor core 51 of the core body 5 through the coil spring 12, and transmitted from this conductor core 51 to the position detection sensor by electrostatic coupling.

In this embodiment, as shown in FIG. 1B, the shielding member holding portion 13 is provided in the hollow portion of the front cap 3 so as to be sandwiched between the cylindrical portion 8c of the holder portion 8 and the cylindrical portion 3a of the front cap 3. This shielding member holding portion 13 is configured to extend from the cylindrical portion 3a to the tapered portion 3b side in the hollow portion of the front cap 3. Then, a shielding member 14, which is configured by winding a coil made of a conductive metal around the outer periphery of this shielding member holding portion 13 in this example, is disposed. This shielding member 14 is intended to prevent noise from being taken into the conductor core portion 51 of the core body 5, and is connected to the ground conductor of the printed circuit board 10, for example.

The end face forming part 73 has a fitting recess 73a, and is joined to the core body fitting member main body part 71 by fitting the fitting protrusion 71b of the core body fitting member main body part 71 into the fitting recess 73a. This end face forming part 73 has a surface that faces the displacement detection part 6 through the space of the hollow part 11a of the holding member 11, and this surface constitutes the end face 7S, and the end face 7S is mirror-finished to reflect light well. The end face forming part 73 is made of a material that can be mirror-finished, for example, a metal such as SUS (Steel Use Stainless).

The end face forming portion 73 is disposed within the hollow portion 11a of the holding member 11 so as to be movable in the axial direction. Therefore, the core body fitting member 7 is movable by the end face forming portion 73 moving in the axial direction relative to the holding member 11. However, as shown in FIG. 1(A), a step portion 11b is formed on the core body 5 side of the hollow portion 11a of the holding member 11, and this step portion 11b abuts against the end portion on the core body 5 side of the end face forming portion 73, so that the core body fitting member 7 does not fall out toward the core body 5 side.

In this embodiment, an elastic member 15 is disposed between the flange portion 71c of the core fitting member main body portion 71 and the end portion of the holding member 11 on the core 5 side. In this example, the elastic member 15 is made of a high-performance urethane foam material, such as a micropolymer sheet Poron (registered trademark), which has high recovery properties against compression and high shock absorption performance.

In this embodiment, the elastic member 15, together with the elastic member 4 between the tip 5b of the core body 5 and the front cap 3 described above, serves as a return elastic member for returning the core body 5 and the core body fitting member 7 to their original positions when the pressure (writing pressure) applied to the tip 5b of the core body 5 is removed after the core body 5 and the core body fitting member 7 have moved in the axial direction due to the pressure. In this embodiment, when pressure is applied to the tip 5b of the core body 5, the core body 5 and the core body fitting member 7 displace in the axial direction by an amount corresponding to the applied pressure against the elastic force of the elastic member 4 and the elastic member 15, and the end face 7S displaces in the axial direction in response to this displacement.

The processing of the writing pressure detection circuit 67 of the displacement detection unit 6 will be described. The writing pressure detection circuit 67 receives information on the phase difference between the emitted light Tp and the received light Rp at the position of the end surface 7S when no pressure is applied to the tip 5b of the core body 5 from the TOF controller 63, and stores the information on the phase difference between the emitted light Tp and the received light Rp when the writing pressure is zero. The stored information on the phase difference between the emitted light Tp and the received light Rp when the writing pressure is zero may be updated periodically, or may be configured to be updated by a user's instruction using, for example, a side switch of the electronic pen 1.

As described above, when pressure is applied to the tip 5b of the core 5, the end surface 7S exhibits an axial displacement corresponding to the magnitude of the applied pressure. In response to this displacement of the end surface 7S, the TOF controller 63 detects a phase difference between the emitted light Tp and the received light Rp that is different from the phase difference between the emitted light Tp and the received light Rp when the writing pressure is zero, and supplies information on the detected phase difference between the emitted light Tp and the received light Rp to the writing pressure detection circuit 67.

The pen pressure detection circuit 67 detects the displacement Δd of the end face 7S in response to the applied pressure from the difference ΔPHd between the phase difference between the emitted light Tp and the received light Rp when the stored pen pressure is zero and the phase difference between the emitted light Tp and the received light Rp at a position after pressure is applied to the tip 5b of the core body 5 and the end face 7S is displaced in the axial direction.

That is, in the writing pressure detection circuit 67, a time Δt corresponding to the difference ΔPHd in the phase difference of light is calculated, and when the speed of light is Cv,
Δd=Δt×Cv/2 (Formula 1)
and detects the displacement Δd of the end face 7S in response to the applied pressure.

In this embodiment, as described above, when pressure is applied to the tip 5b of the core 5, the core 5 and the core fitting member 7 are displaced in the axial direction against the elastic forces of the elastic members 4 and 15, so the writing pressure detection circuit 67 detects the writing pressure taking into account the elastic coefficients of the elastic members 4 and 15. Here, the elastic coefficient k1 of the elastic member 4 is known, and the elastic coefficient k2 of the elastic member 15 is also known, so the writing pressure detection circuit 67 calculates the pressure applied to the tip 5b of the core 5, i.e., the writing pressure F, as
F=Δd×(k1×k2/(k1+k2)) (Formula 2)
It is calculated as follows.

The information on the pen pressure F calculated as described above is supplied from the pen pressure detection circuit 67 to the signal processing circuit 9. The signal processing circuit 9 converts the information on the pen pressure F, for example, into a digital signal, supplies it to the conductor core portion 51 of the core body 5, and is detected by the position detection device via the position detection sensor.

As described above, the electronic pen 1 of this embodiment is provided with a displacement detection unit 6 that optically detects the axial displacement of the end face 7S, which displaces axially together with the core body 5 depending on the magnitude of pressure (writing pressure) applied to the tip portion 5b of the core body 5, and is configured to detect the writing pressure in the writing pressure detection circuit 67 based on the displacement detected by this displacement detection unit 6.

Therefore, with the electronic pen 1 of this embodiment, the configuration for detecting pen pressure can be simplified, and since the axial displacement of the core body and the core body fitting member in response to the applied pressure is not directly transmitted as pressure to the pen pressure detection unit, there is no problem of defects in the pressure detection unit as in the conventional case due to direct exposure to pressure.

In addition, in the electronic pen 1 of this embodiment, the displacement corresponding to the applied pressure is not detected as a change in capacitance, inductance, or resistance value as in the conventional case, and the writing pressure is detected from the detection results, but the displacement corresponding to the applied pressure is optically detected, and the writing pressure is detected from the detected displacement, so that detection can be performed with good responsiveness. It is also easy to determine the starting point for detecting pressure (writing pressure).

In addition, in the electronic pen 1 of the above-mentioned embodiment, the displacement detection unit 6 can be constructed using a commonly used TOF sensor, which has the advantage of making the configuration simpler.

Second Embodiment
In the above-described first embodiment, a TOF sensor is used to detect only the writing pressure, but in the second embodiment, a TOF sensor is used to detect the inclination of the housing of the electronic pen 1. Fig. 4 shows an enlarged cross-sectional view of the pen tip side of the electronic pen 1A of the second embodiment.

In the electronic pen 1A of the second embodiment shown in the example of Figure 4, parts similar to those of the electronic pen 1 of the first embodiment described above are given the same reference numerals, and detailed descriptions thereof are omitted. Also, although the configuration is slightly different from that of the parts in the electronic pen 1 of the first embodiment, corresponding parts are indicated by adding the suffix A to the same reference numerals in the electronic pen 1A of the second embodiment shown in the example of Figure 3.

As shown in Figure 4, the core body 5 and the core body fitting member 7 of the electronic pen 1A of this second embodiment have the same configuration as the electronic pen 1 of the first embodiment. The displacement detection unit 6A, as shown in Figure 6 described later, is different only in that it includes a TOF controller 63A having a function of detecting a phase difference for tilt detection as a phase difference between emitted light and received light, and a tilt detection circuit 68 is added, but the other configuration is the same as the displacement detection unit 6 of the electronic pen 1 of the first embodiment.

In the electronic pen 1A of the second embodiment, the holder portion 8A that holds the displacement detection unit 6A is attached to the end of the cylindrical housing 2A made of, for example, SUS on the pen tip side so as to be fixed in a state where it cannot move in the axial direction. In the example of Figure 4, the protrusion 2Aa of the housing 2A fits into the recess 8Ad of the holder portion 8A, thereby fixing the holder portion 8A to the housing 2A. The holder portion 8A also includes a board mounting base portion 8Ab, similar to the holder portion 8 of the electronic pen 1 of the first embodiment, and a printed circuit board 10 on which ICs that constitute the signal processing circuit 9A are arranged is mounted on the board mounting base portion 8Ab.

The signal processing circuit 9A has a configuration similar to that of the signal processing circuit 9 in the electronic pen 1 of the first embodiment, except that the signal supplied to the conductor core portion 51 of the core body 5 includes tilt information detected by the tilt detection circuit 68 of the displacement detection unit 6A.

In the electronic pen 1A of this second embodiment, a front cap 3A is attached, via a light-transmitting portion 16, to the end portion on the pen tip side, where the core body 5 in the axial direction is arranged, of the housing 2A to which the holder portion 8A that holds the displacement detection unit 6A is fixed.

In this example, the light transmitting portion 16 is made of a cylindrical light transmitting resin or glass member, and its inner wall surface side is configured to be a concave lens as shown in Figure 4. In this example, the light transmitting portion 16 is bonded to the housing 2A and the front cap 3A by, for example, an adhesive. Note that when the light transmitting portion 16 is made of glass, it may be bonded to the housing 2A and the front cap 3A by, for example, melting it with a laser.

The front cap 3A is made of an insulating material, for example, resin, and in the electronic pen 1A of this second embodiment, it is configured to have only a portion that corresponds to the tapered portion 3b of the front cap 3 of the electronic pen 1 of the first embodiment. In this example, a shielding member 14A made of a conductive material, in this example, a conductive metal, is provided on the outer peripheral surface of the front cap 3A at a position surrounding at least the conductor core portion 51 of the core body 5.

In this example, a holding portion 3Ad for the core body fitting member 7 is integrally formed on the front cap 3A, and this holding portion 3Ad holds the core body fitting member 7 in a state in which it can move in the axial direction with its end face 7S facing the displacement detection unit 6A, similar to the electronic pen 1 of the first embodiment.

In the electronic pen 1A of this second embodiment, a ring-shaped lens 17 is disposed in the space between the displacement detection unit 6 and the end face 7S, which is surrounded by the light-transmitting portion 16, to guide the laser light from the light-emitting portion of the displacement detection unit 6A not only to the end face 7S but also to the light-transmitting portion 16 side, and to collect reflected light from the outside through the light-transmitting portion 16 so that it is received by the light-receiving portion of the displacement detection unit 6A.

In addition to the lens 17, a lens may be provided between the displacement detection unit 6A and the end surface 7S to project laser light from the light-emitting unit of the displacement detection unit 6A onto the end surface 7S and receive the reflected light at the light-receiving unit of the displacement detection unit 6A. However, these lenses are not essential and do not have to be provided.

The electronic pen 1A of the second embodiment is configured as described above, so that the displacement detection unit 6A detects the axial displacement of the end face 7S, thereby detecting the pressure (writing pressure) applied to the tip 5b of the core body 5, in the same manner as the electronic pen 1 of the first embodiment.

5, in the electronic pen 1A of the second embodiment, the emitted light Tp of the laser light from the light-emitting section of the displacement detection unit 6A is projected onto the sensor surface (position indication input surface) 100S of the position detection sensor through the light-transmitting section 16, and the received light Rp of the light reflected from the sensor surface 100S is received by the light-receiving section of the displacement detection unit 6A through the light-transmitting section 16. The displacement detection unit 6A detects the tilt angle θ of the electronic pen 1A with respect to the sensor surface 100S of the position detection sensor based on the phase difference between the emitted light Tp at this time and the received light Rp of the light reflected from the sensor surface 100S.

Figure 6 is a diagram showing an example of the configuration of the displacement detection unit 6A of the electronic pen 1A of the second embodiment. As shown in Figure 6, the displacement detection unit 6A of the electronic pen 1A of the second embodiment is provided with a TOF controller 63A having a function for detecting the tilt angle of the electronic pen 1A, and a pen pressure detection circuit 67 and a tilt detection circuit 68 are connected to the TOF controller 63A. The other configurations are the same as those of the displacement detection unit 6 of the electronic pen 1 of the first embodiment.

In this example, the TOF controller 63A of the displacement detection unit 6A detects not only the phase difference PHd1 between the received light Rp and the emitted light Tp from the end face 7S, but also the phase difference PHd2 between the received light Rp and the emitted light Tp of the reflected light from the sensor face 100S of the position detection sensor. In this case, since the distance between the sensor face 100S of the position detection sensor and the displacement detection unit 6A is large compared to the distance between the end face 7S and the displacement detection unit 6A, the magnitudes of the phase differences PHd1 and PHd2 are also significantly different, and the TOF controller 63A can detect the phase differences PHd1 and PHd2 separately.

The TOF controller 63A detects the difference ΔPHd1 between the phase difference value when no pressure is applied to the tip 5b of the core body 5 and the phase difference value when pressure (writing pressure) is applied to the tip 5b of the core body 5, in the same manner as the TOF controller 63 of the displacement detection unit 6 of the electronic pen 1 of the first embodiment, and supplies the difference ΔPHd1 to the writing pressure detection circuit 67. As described above, the writing pressure detection circuit 67 detects the pressure (writing pressure) applied to the tip 5b of the core body 5 using (Equation 1) and (Equation 2).

Then, for the phase difference PHd2, the TOF controller 63A supplies information on the phase difference PHd2 to the tilt detection circuit 68. In this example, the tilt detection circuit 68 has a correspondence table between the value of the phase difference PHd2 and the tilt angle θ of the electronic pen 1A relative to the sensor surface 100S, and by referring to this correspondence table using the value of the phase difference PHd2, the tilt angle of the electronic pen 1A at that time is detected.

In this case, the information of the correspondence table can be formed by measuring the value of the phase difference PHd2 at each inclination angle of, for example, 1 degree increments in the range of the inclination angle θ from 0 degrees to 90 degrees, and storing the corresponding values. Note that the inclination angle can be formed by measuring the value of the phase difference PHd2 at each rough inclination angle of, for example, 5 degrees increments in the range of 0 degrees to 90 degrees, and storing the corresponding values, and the intermediate inclinations at each 5 degree increments can be calculated by interpolation.

The tilt detection circuit 68 can calculate the distance between the displacement detection unit 6A and the sensor surface 100S by calculation from the value of the phase difference PHd2. Since the distance between the tip 5b of the core body 5 and the displacement detection unit 6A is constant and the central axis direction of the light emitted from the displacement detection unit 6A and the light received through the light transmitting portion 16 relative to the axial direction of the electronic pen 1A is fixed, the tilt detection circuit 68 can also calculate the tilt angle θ of the electronic pen 1A from the distance calculated from the value of the phase difference PHd2.

The information on the tilt angle θ of the electronic pen 1A detected as described above is supplied from the tilt detection circuit 68 to the signal processing circuit 9A. The signal processing circuit 9A supplies the information on the writing pressure detected by the writing pressure detection circuit 67 and the information on the tilt angle θ detected by the tilt detection circuit 68 to the conductor core portion 51 of the core body 5 as additional information for the position detection signal.

The electronic pen 1A of this second embodiment has the remarkable effect of being able to obtain information on the inclination angle θ of the electronic pen 1A in addition to information on the writing pressure from the displacement detection unit 6A.

[Other embodiments or modifications]
In the electronic pens 1 and 1A of the first and second embodiments described above, the elastic member 4 is provided between the tip 5b of the core body 5 and the tip end of the front cap 3, 3A, but this elastic member 4 may be omitted and a space in the axial direction may be provided between the front cap 3, 3A and the ring-shaped end surface 5c of the step portion of the tip 5b of the core body 5. In this way, when the elastic member 4 is omitted, there is no need to provide a step portion having the ring-shaped end surface 5c of the tip 5b of the core body 5, so the core body 5 may be rod-shaped with a constant diameter from the tip to the rear end, or the cover portion 52 may be omitted and the core body 5 may be composed of only the conductor core portion 51.

In addition, although the elastic member 15 is made of a high-performance urethane foam member in the above embodiment, it may be made of other configurations such as a coil spring. The position of the elastic member 15 is not limited to the position between the core body fitting member 7 and the holding member 11 as in the above embodiment, as long as it can return the core body fitting member 7 and the core body 5 to the state before pressure is applied. For example, the elastic member 15 may be provided between the end surface 7S and the holder portion 8, 8A that holds the displacement detection portion 6, 6A, as long as it is a position that does not interfere with or affect the emitted light and received light from the displacement detection portion 6, 6A.

In the above embodiment, the end surface 7S is configured to be a mirror-finished surface of the end surface forming portion 73 at the rear end side of the core body fitting member 7 into which the core body 5 is fitted, but the end surface forming portion having a mirror-finished surface at the rear end side of the core body 5 may be fitted. Furthermore, the end surface at the rear end side of the core body 5 itself may be mirror-finished to form the end surface 7S.

In the above embodiment, the end face 7S is disposed so as to be perpendicular to the axial direction of the electronic pen 1, 1A, but it is not necessary for them to be perpendicular. Also, the displacement detection units 6, 6A do not have to be disposed at the center of the axial direction of the electronic pen as long as they can project light onto the end face 7S and receive the reflected light.

In the electronic pen 1A of the second embodiment described above, the light transmitting portion 16 is configured as a cylindrical portion with a constant diameter, but it may be formed so as to extend over a portion of the tapered portion of the front cap 3A. Also, the light transmitting portion 16 may be provided only on the tapered portion of the front cap 3A.

In the electronic pen 1A of the second embodiment described above, the light-transmitting portion 16 is configured as a concave lens, but it is not necessarily required to have a lens configuration such as this example.

In the electronic pen 1A of the second embodiment described above, the displacement detection unit 6A is configured to include both the tilt detection circuit 68 and the writing pressure detection circuit 67, but it may include only the tilt detection circuit 68. In that case, the writing pressure detection unit may be a conventional writing pressure detection unit as described at the beginning, rather than an optical configuration using the displacement detection unit.

The electronic pens 1 and 1A of the first and second embodiments described above are examples of active capacitance type electronic pens, but are not limited to this and may be, for example, electromagnetic induction type electronic pens.

Furthermore, the position indicator of the present invention is not limited to the configuration of a pen-shaped electronic pen, but may be of any shape as long as it has a core body and a pen pressure detection unit.

Furthermore, it goes without saying that the displacement detection units 6, 6A are not limited to configurations using TOF sensors.

1, 1A... electronic pen, 2, 2A... housing, 3, 3A... front cap, 4... elastic member, 5... core body, 6, 6A... displacement detection section, 7... core body fitting member, 8, 8A... holder section, 9... signal processing circuit, 10... printed circuit board, 15... elastic member, 16... light transmission section, 17... lens

Claims (16)

A core body having a tip portion protruding from an opening of the housing and disposed so as to be displaceable in response to pressure applied to the tip portion;
an end surface that exhibits a displacement corresponding to the displacement of the core body;
a displacement detection unit that detects a displacement of the end surface in response to the pressure;
An electronic pen comprising:
the end surface is an end surface of a core body fitting member into which the end surface of the core body opposite to the tip portion is fitted and which displaces in response to displacement of the core body,
the displacement detection unit includes a light emitting unit and a light receiving unit, and is configured such that light emitted from the light emitting unit is projected onto the end face, and the light receiving unit receives light that is reflected from the end face and returns, and detects the displacement of the end face based on a phase difference between the light emitting light and the light receiving light;
A position indicator comprising: a displacement detecting unit that detects a pressure applied to the core body based on the displacement detected by the displacement detecting unit. The position indicator according to claim 1 , wherein the end surface is mirror-finished. an elastic member for restoring the displaced core body and the end face to a state before the displacement when the pressure is applied when the pressure is no longer applied to the end of the core body;
3. The position indicator according to claim 1, wherein the applied pressure is calculated based on the displacement detected by the displacement detection section and an elastic coefficient of the elastic member. The position indicator according to claim 3 , wherein the elastic member is provided between a member that is immovable within the housing and the core body fitting member. The core body includes a core body main body portion smaller than the size of the opening of the housing, and a tip portion located on one end side of the core body main body portion in the axial direction and larger than the size of the opening of the housing, and a ring-shaped end surface is provided between the tip portion and the core body main body portion,
The position indicator according to claim 3 , wherein the elastic member is provided between the ring-shaped end surface and an end surface of the opening of the housing. A core body having a tip portion protruding from an opening of the housing and disposed so as to be displaceable in response to pressure applied to the tip portion;
an end surface that exhibits a displacement corresponding to the displacement of the core body;
a displacement detection unit that detects a displacement of the end surface in response to the pressure;
An electronic pen comprising:
the displacement detection unit includes a light emitting unit and a light receiving unit, and is configured such that light emitted from the light emitting unit is projected onto the end face, and the light receiving unit receives light that is reflected from the end face and returns, and detects the displacement of the end face based on a phase difference between the light emitting light and the light receiving light;
Detecting a pressure applied to the core body based on the displacement detected by the displacement detection unit;
the housing includes a light transmitting portion on a side on which the core body is disposed in an axial direction,
The light emitted from the light emitting unit is projected onto a position indication input surface through the light transmitting unit,
The light receiving unit receives reflected light from the position indication input surface, and detects the inclination of the housing with respect to the position indication input surface based on a phase difference between the received light and the emitted light.
A position indicator characterized by: 7. The position indicator according to claim 6 , wherein the light transmitting section is configured with a lens that converges the reflected light from the position indication input surface and guides it to the light receiving section. The position indicator according to claim 6 or 7 , wherein the end surface is an end surface opposite to a tip end portion of the core body. The position indicator according to any one of claims 6 to 8, characterized in that the end face is an end face of a core body fitting member into which the side opposite the tip portion of the core body is fitted and which displaces in response to the displacement of the core body. The position indicator according to claim 9 , wherein the end surface is mirror-finished. 11. The position indicator according to claim 1, wherein the displacement detection unit is configured using a TOF (Time Of Flight) sensor. The position indicator according to any one of claims 1 to 11 , characterized in that the light emitted from the light emitting portion is pulse modulated. The core body is configured to be displaced in an axial direction of the core body in response to pressure applied to the tip portion,
The position indicator according to any one of claims 1 to 12 , wherein the displacement detection section is disposed opposite to the end face. The position indicator according to claim 13 , wherein the end face is an end face in a direction perpendicular to an axial direction of the core body, and the displacement detection unit is disposed opposite the end face in the axial direction of the core body. A housing configured such that one side in an axial direction serves as a position indicating end;
A displacement detection unit provided in the housing;
Equipped with
a light transmitting portion is provided on the position indication end side of the housing,
the displacement detection unit includes a light-emitting unit and a light-receiving unit, and is configured such that light emitted from the light-emitting unit is projected onto a position indication input surface through the light-transmitting unit;
a light receiving unit receiving reflected light from the position indication input surface, and detecting an inclination of the housing with respect to the position indication input surface based on a phase difference between the received light and the emitted light. 16. The position indicator according to claim 15 , wherein the light transmitting section is configured with a lens that converges the reflected light from the position indication input surface and guides it to the light receiving section.

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