JP2010127671A - Position detector and electro-optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To construct inexpensively an optical position detecting means. <P>SOLUTION: The position detector 100, for optically detecting a plane position of an objective body within a detection plane range 10R constructed into a polygon shape, includes: a first position detecting light source 12A emitting first position detecting light 12A; a second position detecting light source 12B emitting second position detecting light 12B; a light guide plate 13 having a first light incidence plane 13a taking the first position detecting light inside, a second light incidence plane 13b taking the second position detecting light inside, and a light emission surface 13s emitting the first and the second position detecting light propagating inside and neighboring and crossing to the first and the second light incidence planes; a light receiving part 15a disposed at the side of emitting the first and the second position detecting light to the light guide plate and directed to the detection plane range; and a light detector 15 disposed adjacent to and outside of a corner of the detection plane range. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a position detection device and an electro-optical device, and more particularly to a structure of a position detection device for optically detecting a planar position of a target object.

In general, a position detection device for detecting a planar position called a touch panel is used to operate a monitor screen. As a type of the touch panel, a resistance film method, an ultrasonic method, a capacitance method, An optical type is known. The resistive film method is low in cost but has low transmittance as well as the electrostatic capacity method, and the ultrasonic method and the electrostatic capacity method have a high response speed but have low environmental resistance. On the other hand, the optical system is characterized in that the environmental resistance, the transmittance, and the response speed can be increased. (For example, see Patent Documents 1 and 2 below).
JP 2004-295644 A JP 2004-303172 A

  However, in the optical touch panel described above, it is necessary to arrange a large number of light sources and photodetectors or optical switches or light guide structures corresponding to the resolution of position coordinates to be detected in the vicinity of the display screen. Therefore, there is a problem that a high manufacturing cost must be borne because of the large number.

  Accordingly, the present invention is to solve the above-described problems, and is to realize a position detection device capable of configuring an optical position detection unit at low cost, and an electro-optical device (display device) using the position detection device. .

  In view of such circumstances, the position detection device of the present invention is a position detection device for optically detecting the planar position of a target object within a detection plane range configured in a polygonal shape, and includes a first position detection device. A first position detection light source that emits light, a second position detection light source that emits second position detection light, a first light incident surface that incorporates the first position detection light inside, The second light incident surface that takes the second position detection light inside, and the first light that is adjacent to, intersects with, and propagates through the first light incident surface and the second light incident surface. A light guide plate having a position detection light and a light emission surface for emitting the second position detection light, and disposed on the light emission side of the first position detection light and the second position detection light with respect to the light guide plate A light receiving portion directed to the detection plane range, and a corner portion of the detection plane range. Comprising a light detector disposed adjacent to the side, a.

  According to this invention, the first position detection light and the second position detection light are emitted from the light exit surface of the light guide plate, and this is the emission side of the first position detection light and the second position detection light of the light guide plate. When the reflected light is reflected by the target object arranged in, the reflected light is detected by the photodetector. The distance of the first position detection light and the second position detection light reflected by the target object propagating through the light guide plate (from the light exit surface after entering from the first light incident surface and the second light incident surface) The distance until the light is emitted varies depending on the planar position of the target object on the light emission side of the light guide plate. Therefore, by detecting the first position detection light and the second position detection light by the photodetector, it is possible to acquire information on the planar position of the target object based on the light amount ratio, phase difference, etc. of both position detection lights. It becomes possible.

  In the present invention, the first position detection light and the second position detection light are emitted in parallel from the light emission surface of the light guide plate in a plane shape, thereby making it possible to acquire information on the planar position of the target object as described above. Since it is configured, it is not necessary to arrange a large number of optical elements, optical switches, light guide structures, photodetectors, and the like along the detection plane range, so that the position detection device can be configured at low cost.

  In addition, when the light detector is positioned adjacent to the outside of the corner of the polygonal detection plane range with the light receiving portion facing the detection plane range, the detectable angle range of the photodetector is narrow However, it is possible to detect reflected light incident from any position within the detection plane range without separating the light receiving portion of the photodetector from the detection plane range. Therefore, the restriction on the detectable angle range of the photodetector is reduced, and the number of photodetectors can be reduced, the acquisition cost of the photodetectors can be reduced, and the selection range can be expanded. Since it can be arranged close to the range, the frame area extending outside the detection plane range can be reduced, and the position detector can be downsized.

  In one aspect of the present invention, in the light guide plate, the first light incident surface and the second light incident surface are provided at positions facing each other, and the first position detection light source and the second light incident surface are provided. The position detection light sources are arranged at positions facing each other with the light guide plate interposed therebetween. If it does in this way, since the 1st position detection light and the 2nd position detection light will propagate in the inside of a light guide plate in the opposite direction mutually from the position which mutually counters, the 2nd according to the plane position of a target object Since the internal propagation distance of the first position detection light and the internal propagation distance of the second position detection light have a complementary relationship (a relationship in which one increases and the other decreases), the first position detection light source It is possible to easily and accurately acquire the plane position information of the target object in the direction connecting the second position detection light source and the second position detection light source.

  In another aspect of the invention, the detection plane range is configured in a rectangular shape. A rectangular shape is the most common and preferable as the detection plane range. Further, since a rectangular shape is the most common and preferable on the display screen, it is effective to set a detection plane range having a shape corresponding to the display screen.

  In another aspect of the present invention, there is further provided position information acquisition means for obtaining planar position information of the target object based on detection values of the first position detection light and the second position detection light by the photodetector. It has. This position information acquisition means does not need to be included in the position detection device itself, and may be configured by, for example, a control unit (MPU; microprocessor unit or electronic circuit) in an electronic device in which the position detection device is mounted. However, by providing the position detection device with the position information acquisition means, the acquired position information can be output as it is to an electronic device to be mounted. For example, the position information acquisition means derives data such as a light amount ratio and a phase difference between the first position detection light and the second position detection light based on the detection signal of the photodetector, and detects the target object from this data. Find the position within the plane range.

  Next, the electro-optical device of the present invention has the following configuration for optically detecting the plane position of the target object within the detection plane range configured in a polygonal shape, and (a) emits first position detection light. A first light source for position detection, (b) a second light source for position detection that emits second position detection light, and (c) a first light incident surface that incorporates the first position detection light inside. And the second light incident surface that takes the second position detection light inside, and the first light incident surface and the second light incident surface that are adjacent to, intersect, and propagate through the second light incident surface. A light guide plate having a light output surface for emitting the first position detection light and the second position detection light, and (d) the first position detection light and the second position detection light with respect to the light guide plate. A light receiving portion disposed on the emission side and directed to the detection plane range is provided outside the corner portion of the detection plane range. A position detection device having a photodetector arranged in contact with the display area, at least a part of which overlaps the detection plane range, and the first position detection light and the second position with respect to the photodetector. And an electro-optical panel disposed on the opposite side to the traveling direction of the detection light.

  According to this invention, the first position detection light and the second position detection light are emitted from the light exit surface of the light guide plate, and this is the emission side of the first position detection light and the second position detection light of the light guide plate. When the reflected light is reflected by the target object arranged in, the reflected light is detected by the photodetector. The distance of the first position detection light and the second position detection light reflected by the target object propagating through the light guide plate (from the light exit surface after entering from the first light incident surface and the second light incident surface) The distance until the light is emitted varies depending on the planar position of the target object on the light emission side of the light guide plate. Therefore, by detecting the first position detection light and the second position detection light by the photodetector, it is possible to acquire information on the planar position of the target object based on the light amount ratio, phase difference, etc. of both position detection lights. It becomes possible.

  In the present invention, the first position detection light and the second position detection light are emitted in parallel from the light emission surface of the light guide plate in a plane shape, thereby making it possible to acquire information on the planar position of the target object as described above. Since it is configured, it is not necessary to arrange a large number of optical elements, optical switches, light guide structures, photodetectors, and the like along the detection plane range, so that the position detection device can be configured at low cost.

  In addition, when the light detector is positioned adjacent to the outside of the corner of the polygonal detection plane range with the light receiving portion facing the detection plane range, the detectable angle range of the photodetector is narrow However, it is possible to detect reflected light incident from any position within the detection plane range without separating the light receiving portion of the photodetector from the detection plane range. Therefore, the restriction on the detectable angle range of the photodetector is reduced, and the number of photodetectors can be reduced, the acquisition cost of the photodetectors can be reduced, and the selection range can be expanded. Since it can be arranged close to the range, the frame area extending outside the detection plane range can be reduced, and the position detector can be downsized.

  In one aspect of the present invention, the electro-optical panel is disposed between the light guide plate and the photodetector, and the display region can transmit the first position detection light and the second position detection light. It is configured. According to this, since the electro-optical panel is disposed between the light guide plate and the photodetector, an image formed in the display region can be viewed on the viewing side of the electro-optical device without the light guide plate (operation of the position detection device). Side, the same shall apply hereinafter), so that the display screen can be clearly displayed. Further, the first position detection light and the second position detection light emitted from the light guide plate are transmitted through the display area of the electro-optical panel and emitted onto the display screen.

  However, if the light guide plate is configured so that the display region of the electro optical panel can be seen through when the electro optical panel is disposed behind the light guide plate when viewed from the viewing side, the light guide plate is connected to the electro optical panel and the photodetector. You may arrange between them.

  In another aspect of the invention, the electro-optical panel includes an electro-optical material disposed between a first substrate and a second substrate, and the first substrate has an outer shape of the second substrate. A substrate projecting portion projecting around is provided, and the photodetector is disposed to overlap the substrate projecting portion in a planar manner. According to this, because the photodetector is arranged in a plane overlapping with the substrate overhanging portion, even if the photodetector is arranged outside the detection plane range, the reason is simply to arrange the photodetector. Since there is no need to expand the space outside the display area or detection plane range from the display area, the frame area outside the display area or detection plane range is reduced, and the size of the device is reduced while ensuring the space for arranging the photodetectors. Can be achieved. In addition, an electronic component or a wiring member may be mounted on the board extension part.

  In another aspect of the present invention, the electro-optical panel is a liquid crystal panel, and the electro-optical device includes an illumination light source, a light incident surface that incorporates illumination light emitted from the illumination light source, and the light. And a light guide plate for illumination that is disposed so as to overlap with the electro-optic panel in a planar manner. The light guide plate for illumination may be disposed between the light guide plate and the electro-optical panel when the light guide plate for illumination is disposed behind the electro-optical panel as a so-called backlight (opposite to the viewing side), or You may arrange | position on the opposite side to the said electro-optical panel with respect to the said light-guide plate.

  In still another aspect of the present invention, there is provided position information acquisition means for obtaining planar position information of the target object based on detection values of the first position detection light and the second position detection light by the photodetector. In addition. The position information acquisition unit does not need to be included in the electro-optical device itself, and may be configured by, for example, a control unit (MPU; microprocessor unit or electronic circuit) in an electronic device in which the electro-optical device is mounted. However, by providing the electro-optical device with position information acquisition means, the acquired position information can be output as it is to an electronic device to be mounted. For example, the position information acquisition means derives data such as a light amount ratio and a phase difference between the first position detection light and the second position detection light based on the detection signal of the photodetector, and detects the target object from this data. Find the position within the plane range.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is a schematic cross-sectional view schematically showing a configuration of a position detection device or an electro-optical device according to the first embodiment of the present invention, and FIG. 2 is a detection plane range and detection of a photodetector in the position detection device or the electro-optical device. FIG. 3 is an exploded perspective view showing the main configuration of the position detection device or the electro-optical device, and FIG. 4 is a plan view of the position detection light source and the light guide plate and can be detected by the photodetector. It is a top view which shows the relationship with an angle range.

  Each of the embodiments described below corresponds to both the position detection device and the electro-optical device of the present invention, and the position detection device of the present invention includes an electro-optical panel from each embodiment. It is also possible to adopt a configuration in which (liquid crystal display panel) is removed. However, in the following description, each embodiment is simply referred to as an electro-optical device.

  The electro-optical device 100 of the present embodiment includes a position detection unit 10 and an electro-optical panel 20 combined with the position detection unit 10. As shown in FIGS. 3 and 4, the position detection unit 10 includes position detection light sources 12A to 12D that emit position detection lights L2a to L2d and light incident surfaces 13a to 13d on which the position detection lights L2a to L2d are incident. The light guide plate 13 is provided on one end surface (upper surface in the drawing) with a light emitting surface 13s that is emitted after the position detection lights L2a to L2d have propagated through the inside. The position detection light sources 12A to 12D are disposed so as to face the light incident surfaces 13a to 13d, and are preferably disposed so as to be in close contact with the light incident surfaces 13a to 13d.

  The position detection light sources 12A to 12D are configured by light emitting elements such as LEDs (light emitting diodes), for example, and emit position detection lights L2a to L2d, for example, infrared rays in response to a drive signal output from a drive circuit (not shown). The position detection light is not particularly limited, but is preferably one that can be detected separately from outside light by signal processing or the like described later, and the light emission mode is such that the wavelength distribution is different from visible light or modulation such as blinking is applied. Are preferably different. Moreover, it is preferable to have a wavelength range that is efficiently reflected by the target object Ob such as a finger or a touch pen. For example, if the target object Ob is a human body such as a finger, it is desirable to use infrared rays with high reflectivity on the surface of the human body (particularly near infrared rays close to the visible light region, for example, near 850 nm in wavelength).

  The position detection light sources 12A to 12D are essentially provided in plural, and are configured to emit position detection light from different positions. The first position detection light source and the second position detection light source of the present invention correspond to, for example, any two of the position detection light sources 12A to 12D.

  As shown in FIG. 4, the first position detection light source 12 </ b> A and the second position detection light source 12 </ b> B are disposed opposite to each other on the light incident surfaces 13 a and 13 b of the light guide plate 13 facing each other. The position detection light source 12 </ b> A and the second position detection light source 12 </ b> B are arranged to face each other with the light guide plate 13 interposed therebetween. With this configuration, as shown in FIG. 1, the first position detection light L2a and the second position detection light L2b are propagated in the light guide plate 13 in the opposite directions along the X direction in the figure, The light exits gradually from the light exit surface 13s along the propagation direction.

  Similarly, the first position detection light source 12C and the second position detection light source 12D are arranged to face each other on the light incident surfaces 13c and 13d of the light guide plate 13 facing each other. As a result, the first position detection light source 12D is disposed. The light source 12C and the second position detection light source 12D are disposed so as to face each other with the light guide plate 13 interposed therebetween. With this configuration, the first position detection light L2c and the second position detection light L2d propagate gradually in the propagation direction while propagating in the light guide plate 13 in the opposite directions along the Y direction in the figure. The light exits from the light exit surface 13s.

  The light guide plate 13 is preferably made of a transparent resin material such as polycarbonate or acrylic resin. Moreover, in the example of illustration, it is comprised planarly as a whole by the rectangular shape in planar view. The light guide plate 13 has four end surfaces which are the light incident surfaces 13a to 13d, respectively, and the light sources 12A to 12D (light emitting portions) for position detection face each other on the light incident surfaces 13a to 13d. Has been.

  The light exit surface 13s or the back surface 13t on the opposite side of the light exit surface 13s is provided with a surface uneven structure, a prism structure, a scattering layer, etc. (not shown). By such a light scattering structure, the light entrance surfaces 13a to 13d The light that is incident and propagates inside is gradually deflected as it travels in the propagation direction and is emitted from the light exit surface 13s.

  A light reflection plate 14 composed of a reflection sheet or the like is disposed behind the light guide plate 13 and functions to return the position detection lights L2a to L2d emitted from the back surface 13t of the light guide plate 13 to the inside of the light guide plate 13. .

  Further, on the light emitting side of the light guide plate 13, a light diffusion plate for making the position detection lights L2a to L2d uniform, if necessary, a prism sheet for increasing the directivity of the position detection lights L2a to L2d, etc. An optical sheet 16 such as a light collecting plate is appropriately disposed. In particular, the optical sheet 16 is refracted so that the emission angles of the position detection lights L2a to L2d emitted from the light emission surface 13s of the light guide plate 13 (angle with respect to the normal direction of the light emission surface 13s) become small. It is preferable that the light condensing sheet is used. As a result, the position detection lights L2a to L2d can be efficiently emitted to the viewing side (operation side) so that highly accurate and stable position detection is possible.

  In the electro-optical device 100, an electro-optical panel 20 including a liquid crystal display panel such as a transmissive liquid crystal display body is disposed on the light emitting side of the light guide plate 13. The electro-optical panel 20 includes, for example, transparent substrates 21 and 22 bonded together with a sealing material 23, and a liquid crystal 24 disposed between the substrates. The alignment state of the liquid crystal 24 can be controlled by electrodes (not shown). A plurality of pixels are provided.

  The substrate 21 is provided with a substrate overhanging portion 21t that projects from the outer shape of the substrate 22 to the periphery. An electronic component 25 such as a drive circuit is mounted on the board protruding portion 21t (the surface on the board 22 side). In addition, a wiring member 26 such as a flexible wiring board (FPC) is mounted on the board projecting portion 21t. However, only the wiring member 26 may be mounted on the board overhanging portion 21t, and further, neither the electronic component 25 nor the wiring member 26 may be mounted. In addition, a polarizing plate (not shown) is arrange | positioned at the outer surface side of the board | substrates 21 and 22 as needed. Each pixel arranged in the display area 20R is driven by a drive signal output from a drive circuit made of a semiconductor IC chip or the like composed of the electronic component 25 or the like, and is controlled so as to be in a predetermined transmission state for each pixel. The

  A light-transmitting front panel 30 is disposed on the viewing side (operation side) of the electro-optical panel 20, and the photodetector 15 is disposed on the outer surface of the front panel 30 (the surface opposite to the electro-optical panel 20). Be placed. The photodetector 15 is composed of a light receiving element such as a photodiode, and is configured to be able to detect the intensity of the position detection lights L2a to L2d. For example, as will be described later, if the position detection lights L2a to L2d are infrared rays, the photodetector 15 is also composed of a light receiving element having sensitivity to infrared rays. By selecting the light receiving sensitivity of the photodetector 15 so as to selectively detect the wavelength range of the position detection lights L2a to L2d, the influence of other light such as external light can be reduced.

  On the side of the photodetector 15 of the front panel 30, a surface plate 31 (two in FIG. 1) configured by a frame body for holding and fixing the electro-optical device 100, a housing of an electronic device on which the electro-optical device 100 is mounted, This surface plate 31 has an opening that exposes the detection plane range 10R of the position detection unit 10 and the display area 20R of the electro-optical panel 20 in the front panel 30. 31a is provided.

  Here, the detection plane range 10 </ b> R is a plane range in which the position detection lights L <b> 2 a to L <b> 2 d are emitted to the viewing side (operation side), and as a result, a plane range in which reflected light from the target object Ob can be generated. In the illustrated example, the detection plane range 10R is rectangular and includes four sides 10Ra to 10Rd. Sides 10Ra and 10Rb are short sides, and sides 10Rc and 10Rd are long sides. The inner angle range 10r of the corners of adjacent sides is 90 degrees. In this embodiment, the inner angle range 10r corresponds to the inner angle range 13r of the corner portion of the light guide plate 13 shown in FIG. 4 and is the same angle range. However, the inner angle range 10 r can be set independently of the inner angle range 13 r of the light guide plate 13 by the opening 31 a of the surface plate 31.

  In the illustrated example, the detection plane range 10R is defined by the opening 31a of the front plate 31. However, the present invention is not limited to this, and the electro-optical panel is defined by the light emitting surface 13s itself of the light guide plate 13. As long as the position detection light is emitted to the viewer side (operation side) as a result, such as when defined by 20 position detection light transmission regions or when defined by other light shielding members, the formation mode is It doesn't matter.

  The display region 20R is a planar range in which a display image of the electro-optical panel 20 can be formed. For example, the display region 20R is a range in which a plurality of pixels (not shown) are arranged in the electro-optical panel 20. In the case of the illustrated example, the display region 20R has a rectangular shape with four sides, has a congruent shape with the detection plane region 10R, and its position completely coincides with the detection plane region 10R in a planar manner. However, in the case of the present invention, it is sufficient that at least a part of the detection plane range 10R and the display area 20R overlap in a plane.

  The electro-optical panel 20 of the present embodiment is configured to transmit the position detection lights L2a to L2d at least in the display region 20R. This is because the electro-optical panel 20 is disposed on the viewing side (operation side) with respect to the light guide plate 13, and the position detection light L2a is used to detect the planar position of the target object Ob as described later. This is because it is necessary to emit ~ L2d to the viewing side where the operation with the target object Ob is performed.

  On the other hand, when the electro-optical panel 20 is disposed on the side opposite to the viewing side of the light guide plate 13, the display region 20R is not necessarily configured to transmit the position detection lights L2a to L2d. Instead, the display region R needs to be configured to be visible from the viewing side through the light guide plate 13.

  In addition, unlike the example of illustration, the surface mounting board 30 and the surface board 31 do not need to be provided. For example, the structure may be such that the electro-optical panel 20 is directly exposed without the cover plate 30 being provided.

  As shown in FIG. 1, the photodetector 15 is attached to the opening edge portion 31b of the surface plate 31, and the light receiving portion 15a is fixed in a posture toward the detection plane range 10R. The light receiving portion 15a is exposed at the edge end surface facing the opening 31a on the detection plane range 10R side in the opening edge 31b. In the illustrated example, the photodetector 15 is overlapped with the opening edge 31b in a planar manner and is covered from the viewing side (operation side). Thereby, restrictions on exterior design can be reduced.

  As shown in FIG. 2, in the present embodiment, the photodetector 15 has a corner where the side 10Ra and the side 10Rd intersect (in the illustrated example, one of the two corners on the upper side of the detection plane range 10R in the drawing). The light receiving portion 15a faces the inside of the corner portion. The detectable angle range 15r of the light receiving unit 15a of the light detector 15 is a range of 120 degrees in total of 60 degrees on both sides around the detection center axis 15rs. The detectable angle range 15r is set to include the entire detection plane range 10R. That is, the light detector 15 is configured to be able to detect position detection light from all positions in the detection plane range 10R toward the light receiving unit 15a. In the case of the illustrated example, the detectable angle range 15r (120 degrees) of the light receiving unit 15a is not less than the inner angle range 10r (90 degrees) of the corner, and the detectable angle range 15r includes the entire inner angle range 10r. Configured as follows.

  The photodetector 15 is disposed at a position where it planarly overlaps with the substrate protruding portion 21t provided on the electro-optical panel 20. In particular, in the case of the illustrated example, the entire photodetector 15 is arranged in a range that overlaps the substrate overhanging portion 21t in a plane. The substrate overhanging portion 21t in the illustrated example is formed in an L shape in which the strip-like portions 21ta and 21td along the outside of the sides 10Ra and 10Rd are connected, and the connecting portion of the strip-like portions 21ta and 21td is outside the corner portion. The photodetector 15 is arranged so as to overlap the connecting portion in a plan view.

  The direction of the light receiving unit 15a of the photodetector 15 is particularly limited as long as the detectable angle range 15r is configured to detect reflected light incident from all positions in the detection plane range 10R. Although not shown, in the illustrated example, the light receiving unit 15a is configured such that the detection center axis 15rs of the detectable angle range 15r coincides with the central angle direction of the inner angle of the adjacent corner.

  In the present embodiment configured as described above, the position detection lights L2a to L2d emitted from the position detection light sources 12A to 12D enter the inside of the light guide plate 13 from the light incident surfaces 13a to 13d, respectively. As a result, the position detection lights L2a to L2d are emitted in a planar shape from the light emission surface 13s in parallel. For example, the position detection light L2a is gradually emitted from the light emitting surface 13s while propagating through the light guide plate 13 from the light incident surface 13a toward the light incident surface 13b.

  The position detection lights L2a to L2d pass through the optical sheet 16 and the electro-optical panel 20 and are emitted from the entire detection plane range 10R to the viewing side (operation side) of the front panel 30. When the target object Ob such as a finger is disposed on the viewing side (operation side) of the front panel 30, the position detection lights L2a to L2d are reflected by the target object Ob, and part of the reflected light is detected by the light detection. Detected by the instrument 15.

  In the illustrated example, the position detection light sources 12A to 12D are disposed opposite to each other at the central portions of the light incident surfaces 13a to 13d, which are the end surfaces of the respective sides of the light guide plate 13, and therefore the light of the position detection light sources 12A to 12D. Depending on the emission angle, there may be a region where the position detection lights L2a to L2d are not emitted at a part of the light exit surface 13s, but such a region is set to be excluded from the detection plane range 10R. That is, as described above, the plane range in which the position detection lights L2a to L2d are finally emitted in parallel on the viewing side (operation side) is the detection plane range 10R.

  Next, a method for acquiring position information of the target object Ob based on detection by the photodetector 15 will be described. There are various methods for acquiring the position information. For example, as an example, the ratio of the attenuation coefficients is obtained based on the ratio of the detected light amounts of the two position detection lights, and both are calculated from the ratio of the attenuation coefficients. There is a method of obtaining the position coordinates in the direction connecting two corresponding light sources by obtaining the propagation distance of the position detection light.

  More specifically, a case where 12A is used as the first position detection light source and 12B is used as the second position detection light source will be described. For example, the control amount (for example, current amount) of the first position detection light source 12A is described. ), If the conversion coefficient and the emitted light quantity are Ia, k and Ea, the control amount (current quantity) of the second position detection light source 12B, and the conversion coefficient and the emitted light quantity are Ib, k and Eb, Ea = k · Ia Eb = k · Ib. If the attenuation coefficient and the detected light amount of the first position detection light L2a are fa and Ga, and the attenuation coefficient and the detected light amount of the second position detection light L2b are fb and Gb, Ga = fa · Ea = fa · k. Ia, Gb = fb · Eb = fb · k · Ib

  Therefore, if Ga / Gb, which is the ratio of the detected light amounts of the two position detection lights, can be detected by the photodetector 15, Ga / Gb = (fa · Ea) / (fb · Eb) = (fa / fb) · Since (Ia / Ib) is obtained, if the values corresponding to the ratio Ea / Eb of the amount of emitted light and the ratio Ia / Ib of the control amount are known, the ratio fa / fb of the attenuation coefficient can be determined. Since there is a positive correlation between the ratio of the attenuation coefficient and the ratio of the propagation distances of the two position detection lights, the positional information (first position) of the target object Ob can be obtained by setting this correlation in advance. Position coordinates in a direction from the detection light source to the second position detection light source can be obtained.

  As a method for obtaining the attenuation coefficient ratio fa / fb, for example, the first position detection light source 12A and the second position detection light source 12B are blinked in opposite phases (for example, a rectangular or sinusoidal drive signal is used). The operation is performed so that the phase difference caused by the difference in propagation distance has a phase difference of 180 degrees at a frequency at which the phase difference can be ignored, and the waveform of the detected light quantity is analyzed. More realistically, for example, one control amount Ia is fixed (Ia = Im), and the other control is performed so that the detected waveform cannot be observed (that is, the detected light quantity ratio Ga / Gb becomes 0). The amount Ib is controlled, and the ratio fa / fb of the attenuation coefficient is derived from the control amount Ib = Im · (fa / fb) at this time.

  Further, the control may be performed so that the sum of both control amounts is always constant Im = Ia + Ib. In this case, since Ib = Im · fb / (fa + fb), when fb / (fa + fb) = α, the ratio of the attenuation coefficient is obtained by fa / fb = (1−α) / α.

In the case of the present embodiment, the position information of the target object Ob in the X direction in the figure can be acquired by driving the first position detection light source 12A and the second position detection light source 12B in opposite phases. . Further, the position information of the target object Ob in the Y direction can be acquired by driving the first position detection light source 12C and the second position detection light source 12D in opposite phases. Therefore, the position coordinate on the plane of the target object Ob can be acquired by sequentially performing the detection operation in the X direction and the Y direction in the control system.

  Further, the first position detection light source 12A and 12C are driven in phase, the second position detection light source 12B and 12D are driven in phase, and the first position detection light source and the second position detection light source When the position detection light source is driven and detected in opposite phases, the first position detection light source 12A and 12D are driven in phase and the second position detection light source 12B and 12C are in phase. Or the first position detection light source and the second position detection light source are driven in the opposite phases to detect each other, and the coordinates are obtained sequentially. You can get the upper position coordinates. According to the configuration in which a plurality of such position detection light sources are simultaneously turned on, for example, from the side of 12A and 12C as the first position detection light source, 12B and 12D as the second position detection light sources facing each other. The outgoing light amount distribution on the light exit surface that is desirable for position detection in the direction toward the side or the opposite direction (a good light / dark gradient distribution of the position detection light) is more effective than the configuration in which one position detection light source is turned on. Since it is obtained in a wide range, more accurate position detection is possible.

  As described above, as a method of acquiring the plane position information within the detection plane range 10R of the target object Ob based on the light amount ratio between the first position detection light and the second position detection light detected by the photodetector 15. For example, a configuration in which a microprocessor unit (MPU) is used as position information acquisition means and processing is performed by executing predetermined software (operation program), and hardware such as a logic circuit is used as position information acquisition means. The structure etc. which process using are mentioned. These position information acquisition units may be incorporated as a part of the electro-optical device 100 or may be configured inside an electronic apparatus in which the electro-optical device 100 is mounted.

  In addition to the method based on the light amount ratio between the first position detection light and the second position detection light corresponding to the propagation distance inside the light guide plate 13 as described above, the position information acquisition method, for example, A method based on the phase difference between the first position detection light and the second position detection light corresponding to the propagation distance is also conceivable. In this case, the plane position information of the target object Ob is calculated according to the relationship between the magnitude of the phase difference and the difference in the propagation distance.

  In the present embodiment configured as described above, the position information of the target object Ob can be detected within the detection plane range 10R, but the position detection lights L2a to L2d are used as the light incident surfaces 13a to 13d of the light guide plate 13. Compared to a conventional method in which a large number of light sources, photodetectors, optical switches, or the like are arranged, by emitting light from a light emitting surface 13s that intersects the light incident surface (orthogonal in the illustrated example). Since the number of position detecting elements can be greatly reduced, the structure can be greatly simplified, the manufacturing cost can be reduced, and the power consumption can be reduced.

  In particular, since the first position detection light source and the second position detection light source are arranged at positions facing each other with the light guide plate 13 in between, the first position detection light emitted from each light source. And the second position detection light propagate in the light guide plate 13 in opposite directions, so that the magnitude relationship between the internal propagation distances of both lights reflected by the target object Ob is complementary, that is, When one propagation distance increases, the other propagation distance decreases. Therefore, the position information of the target object Ob in the direction connecting the two light sources can be easily detected with high accuracy.

  Further, according to the present embodiment, as shown in FIG. 2, the photodetector 15 is arranged adjacent to the outside of the corner of the rectangular detection plane range 10R, and the light receiving unit 15a faces the detection plane range 10R. By adopting the posture, even when the detectable angle range 15r of the light receiving unit 15a is limited, it is possible to easily and reliably detect reflected light incident from any position in the detection plane range 10R. . Further, in order to configure in this way, it is necessary to increase the number of photodetectors 15, to separate the photodetectors 15 from the detection plane range 10R, or to use the photodetectors 15 having a wide detectable angle range. Therefore, the manufacturing cost can be reduced and the electro-optical device can be reduced in size.

  In the above-described embodiment, the detection plane range 10R is rectangular. However, the photodetector 15 is arranged at a corner portion in any polygonal detection plane range 10R such as a triangular shape, a quadrilateral shape other than a rectangle, or a pentagonal shape. The effect similar to the above can be acquired by arrange | positioning adjacently outside. Here, the polygonal shape is meant to include polygons with rounded corners, polygons with chamfered corners, and the like.

  In the present embodiment, since the photodetector 15 is disposed in a region that overlaps the substrate overhanging portion 21t of the electro-optical panel 20 in a plane, the planar range of the electro-optical device 100 (particularly, by arranging the photodetector 15). Since the increase amount of the frame area) can be eliminated or reduced, the electro-optical device 100 can be downsized. That is, since the substrate overhang portion 21t is formed outside the display area 20R, there is no problem in disposing the substrate overhang portion 21t outside the detection plane range 10R. Therefore, the detection plane range 10R and the display area 20R are not affected. The space efficiency can be improved by overlapping the portions that are separated from each other in a planar manner.

  In particular, in the present embodiment, the substrate overhanging portion 21t is configured in an L shape formed by connecting strip-like portions 21ta and 21td along two adjacent sides of the detection plane range 10R, and the connecting portion is the photodetector 15. Are provided outside the corners of the detection plane range 10R. Therefore, by configuring the connecting portion and the photodetector 15 so as to overlap with each other in a plane, the photodetector 15 can be easily overlapped with the substrate extension portion 21t in a plane. In particular, the optical detector 15 can be easily configured so as to be within the plane range of the substrate protruding portion 21t.

  In the present embodiment, the position detection light sources 12A to 12D are arranged to face each other at the center of each side of the light incident surfaces 13a to 13d, but the positions of the position detection light sources 12A to 12D on each side are particularly limited. Instead, for example, the position detection light source may be disposed opposite to both ends of each side and the corners of the light guide plate 13. However, it is preferable that the first position detection light source and the second position detection light source are arranged so as to face each other with the light guide plate 13 interposed therebetween.

  Further, in the present embodiment, by disposing the photodetector 15 adjacent to the outside of the corner corresponding to the upper side of the display region 20R (upper corner in the drawing) in the rectangular detection plane range 10R, The reflected light from the target object Ob such as a touch pen can be efficiently reflected. That is, generally, with respect to the reflected light from the tip of the target object Ob, for example, the tip of the finger or the touch pen, the upper part of the display screen where obstacles such as other fingers and palms are difficult to be placed (in the case of this embodiment). Can be reliably and stably detected as compared with the case where a photodetector is disposed below the display screen.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIGS. FIG. 5 is a longitudinal sectional view of the second embodiment, FIG. 6 is a plan view, and FIG. 7 is an exploded perspective view of the main configuration. In the present embodiment, parts corresponding to those in the first embodiment are denoted by the same reference numerals, and description of the same contents as those in the first embodiment is omitted.

  In the present embodiment, the position detection light sources 12A to 12D, the light guide plate 13, the reflection plate 14, the electro-optical panel 20, the front panel 30, and the surface plate 31 similar to those in the first embodiment are provided. It differs from the first embodiment in that an illumination device 40 for illuminating the panel 20 is provided.

  In the present embodiment, the illuminating device 40 includes an illumination light source 41 and an illumination light guide plate 43 that emits the illumination light emitted from the illumination light source 41 while propagating it. The illumination light source 41 is composed of, for example, a light emitting element such as an LED (light emitting diode), and emits, for example, white illumination light L4 according to a drive signal output from a drive circuit (not shown). Preferably, as shown in FIG. 7, a plurality of illumination light sources 41 are arranged along the first light incident surface 43a.

  As shown in FIG. 7, the illumination light guide plate 43 is formed in a rectangular shape in plan view, and the illumination light L4 emitted from the illumination light source 41 is incident from a light incident surface 43a provided on one side thereof. The illumination light L4 is taken in from the light incident surface 43a and propagates toward the outer edge 43b on the opposite side. And the illumination light L4 is radiate | emitted from the light-projection surface 43s which is one surface gradually, propagating through the inside of the light guide plate 43 for illumination.

  In the illumination light guide plate 43 for illumination according to the present embodiment, the ratio of the amount of light emitted from the light exit surface 43s to the internal propagation light monotonically increases from the light incident surface 43a side toward the outer edge 43b on the opposite side. It has a light guide structure. This light guide structure is, for example, the area of the light-reflecting surface 43s of the illuminating light guide plate 43 or the fine concavo-convex refracting surface for light deflection or light scattering formed on the back surface 43t which is the opposite surface. This is realized by gradually increasing the density of the printed scattering layer toward the internal propagation direction. By providing such a light guide structure, the illumination light L4 incident from the light incident surface 43a is emitted substantially uniformly from the light emitting surface 43s. Therefore, in this embodiment, the light guide plate 43 for illumination is used as a planar light source for illumination.

  The illumination light guide plate 43 is disposed on the side opposite to the viewing side of the electro-optical panel 20 so as to overlap the display region 20R of the electro-optical panel 20 in a planar manner, and functions as a so-called backlight. However, the illumination light guide plate 43 may be arranged on the viewing side of the electro-optical panel 20 so as to function as a so-called front light. In the illustrated example, the illumination light guide plate 43 is disposed between the position detection light guide plate 13 and the optical sheet 16. However, the illumination light guide plate 43 may be disposed on the side opposite to the viewing side of the light guide plate 13.

  In the illustrated example, the optical sheet 16 is shared by the light guide plate 13 and the illumination light guide plate 43 (that is, the position detection lights L2a to L2d and the illumination light L4). A dedicated optical sheet different from the optical sheet 16 may be disposed. This is because, in the illumination light guide plate 43 for illumination, a light diffusing plate that exhibits a sufficient light diffusing action in order to uniformize the planar luminance of the illumination light L4 emitted from the light emitting surface 43s is often used. In the position detection light guide plate 13, if the position detection lights L <b> 2 a to L <b> 2 d emitted from the light exit surface 13 s are largely diffused, position detection is hindered. This is because it is necessary to use a light diffusing plate exhibiting a light light diffusing action, and therefore it is preferable to use a dedicated light diffusion plate 43 for the light diffusing plate. However, an optical sheet having a light collecting function such as a prism sheet may be shared.

  In the illumination light guide plate 43 of the present embodiment, an inclined surface 43g is provided on the surface portion on the light emitting side adjacent to the light incident surface 43a (the outer peripheral portion of the light emitting surface 43s on the light incident surface 43a side), Accordingly, the illumination light guide plate 43 is configured to gradually increase in thickness toward the light incident surface 43a. While suppressing an increase in the thickness of the portion where the light exit surface 43s is provided by the light incident structure having the inclined surface 43g, the height of the light incident surface 43a is increased to correspond to the height of the light emission region of the illumination light source 41. To be formed. This is to incorporate light emitted from a light emitting element (illumination light source 41) that has not been miniaturized while reducing the thickness of the illumination light guide plate 43 in order to meet the recent demand for thin display devices. This is to improve efficiency and increase the illumination brightness.

  In the present embodiment, the electro-optical panel 20 is configured as a transmissive or transflective liquid crystal display panel, whereby the display region 20R is configured to transmit not only the position detection lights L2a to L2d but also the illumination light L4. ing. Here, as shown in FIG. 6, the illumination range 43R by the illumination light L4 is a range including the entire display region 20R, and as a result, the entire display region 20R is illuminated in a planar shape.

[Third Embodiment]
Next, a third embodiment according to the present invention will be described with reference to FIG. FIG. 8 is a plan view of this embodiment. In the present embodiment, items not shown and items not described can be configured in the same manner as in the first and second embodiments.

  In the present embodiment, as shown in FIG. 8, the detection angle range 15r of the light receiving unit 15a of the photodetector 15 is the same as described above in that it is set to include all the detection plane range 10R. The difference is that the detection center axis 15rs is directed to a corner facing the corner adjacent to the photodetector 15 in the detection plane range 10R.

  As described above, the detectable angle range 15r of the light receiving unit 15a of the photodetector 15 is configured to include all the directions defined by the inner angle 10r of the corner adjacent to the photodetector 15 in the detection plane range 10R. It is sufficient that the detection center axis 15rs does not need to coincide with the center angle of the inner angle 10r of the corner adjacent to the photodetector 15 in the detection plane range 10R as in the first and second embodiments. However, the detection center axis 15rs is set so as to pass through the opposite corners of the rectangular detection plane range 10R, so that the detectable angle range 15r of the light receiving unit 15a of the photodetector 15 becomes the detection plane range. If the light detector 15 is formed so as to be able to detect reflected light from all positions within 10R, when the light detector 15 is assembled (for example, when fixed to the surface plate 31) The advantage that the positioning or posture of the photodetector 15 can be easily confirmed is obtained.

[Fourth Embodiment]
Next, a fourth embodiment according to the present invention will be described with reference to FIG. FIG. 9 is a plan view of this embodiment. In the present embodiment, items not shown and items not described can be configured in the same manner as in the first and second embodiments.

  In the present embodiment, as shown in FIG. 9, the detectable angle range 15r of the light receiving unit 15a of the photodetector 15 deviates from the adjacent corners of the detection plane range 10R. However, the detectable angle range 15r is set so that reflected light from all other positions in the detection plane range 10R can be detected except for the corner portion. Even if comprised in this way, it is the same as that of each said embodiment in the point by which the photodetector 15 is installed with the attitude | position which faced the said detection plane range 10R in the outer side of the said detection plane range 10R.

  In the present embodiment, as in the illustrated example, in the electro-optical panel 20, the substrate overhanging portion 21t is configured only by the belt-like portion 21ta along the side 10Ra of the detection plane range 10R. Then, the photodetector 15 is arranged so as to be shifted slightly to the side 10Ra side from the corner so as to be within a range overlapping the substrate overhanging portion 21t in plan view.

[Fifth Embodiment]
Next, a fifth embodiment according to the present invention will be described with reference to FIG. FIG. 10 is a plan view of this embodiment. In the present embodiment, items not shown and items not described can be configured in the same manner as in the first and second embodiments.

  In the present embodiment, as shown in FIG. 10, the detectable angle range 15 r of the light receiving unit 15 a of the photodetector 15 is substantially equal to the inner angle 10 r of the corner of the detection plane range 10 R adjacent to the photodetector 15. Configured to match. That is, the detectable angle range 15r is configured to be an angle range between the sides 10Ra and 10Rd adjacent to each other of the detection plane range 10R.

  With this configuration, the light that can be detected by the photodetector 15 is limited to light incident from a position within the detection plane range 10R. The possibility of detection can be reduced.

  In the above description, the detectable angle range 15r of the light receiving unit 15a of the photodetector 15 has been described only as an angular range on a plane on the detection plane range 10R. The part 15a also has a detectable angle range in an angular direction (viewing side or opposite to the viewing side) perpendicular to the plane of the detection plane range 10R, and the detectable angle range in this angular direction is wide. If it is too high, there is an increased possibility of detecting light that should be external light or other noise, or detecting light that is directly incident from the light guide plates 13 and 43. Therefore, it is preferable that the detectable angle range in the angular direction is set as narrow as possible within the range in which the position detection lights L2a to L2d can be reliably detected when the target object Ob such as a finger comes into contact with the cover plate 30.

  However, in the position information acquisition means of the present invention, as described above, the wavelength of the position detection light is set to a wavelength region that is out of the visible light region, or modulation such as blinking of the position detection light is performed. The influence of external light and other noises can be reduced or eliminated.

[Sixth Embodiment]
Next, a sixth embodiment according to the present invention will be described with reference to FIG. FIG. 11 is a plan view of this embodiment. In the present embodiment, items not shown and items not described can be configured in the same manner as in the first and second embodiments.

  In the present embodiment, as shown in FIG. 11, the relationship between the main body shape of the photodetector 15 and the posture of the light receiving portion 15a is different from the above embodiments. In the illustrated example, the photodetector 15 has a rectangular outer shape in plan view, and two adjacent sides of the rectangular shape are adjacent to the outer edge of the planar range of the electro-optic panel 20 (the substrate overhang portion 21t). Are arranged in the corners of the plane range so as to be parallel to each other.

  On the other hand, the light receiving unit 15a of the photodetector 15 has the detectable angle range 15r that is biased with respect to the side of the outer shape of the photodetector 15 on the light receiving unit 15a side. That is, one boundary direction of the detectable angle range 15r is substantially orthogonal to the side on the light receiving unit 15a side of the photodetector 15, and the other boundary direction is substantially parallel to the side on the light receiving unit 15a side. It has become.

  In the illustrated example, the detectable angle range 15r substantially coincides with the incident angle range of reflected light incident from within the detection plane range 10R. That is, one boundary direction of the detectable angle range 15r is the remaining two corner portions (that is, the corner portions adjacent to the photodetector 15 and the corner portions facing the corner portions) in the detection plane range 10R (that is, the corner portions). , The corners formed by intersecting the sides 10Rd and 10Rb, and the corners formed by intersecting the sides 10Ra and 10Rc), and the other boundary direction is defined by the two corners. It is set as the direction which goes to the other corner | angular part among parts.

[Comparative example]
Finally, a comparative example different from the above embodiment will be described with reference to FIGS. FIG. 12 is a plan view showing a case where the photodetector 15 is arranged adjacent to the outside of the central portion of the side 10Rd of the detection plane range 10R.

  As shown in FIG. 12, in this comparative example, the detectable angle range 15r of the light receiving unit 15a of the light detector 15 is within the detection plane range 10R on both sides of the side 10Rd where the light detector 15 is adjacently disposed. The direction toward the regions 10Rx and 10Ry in the vicinity of the corners is not included, and therefore the reflected light from the vicinity of both corners cannot be detected.

  In order to solve the above problem without changing the position of the photodetector 15, it is necessary to widen the detectable angle range 15r or to dispose a plurality of photodetectors 15 to eliminate the undetectable region. However, in such a method, since it is necessary to use a special photodetector or increase the number of photodetectors, the manufacturing cost increases in any case.

  As another solution, as shown in FIG. 13, by moving the photodetector 15 away from the detection plane range 10R, even within the same detectable angle range 15r, the detection plane range 10R is included therein. It is conceivable to configure so as to include azimuths directed to all the positions. However, in this method, it is necessary to increase the distance Lx from the outer edge of the detection plane range 10R to the light receiving unit 15a of the photodetector 15, and to separate the photodetector 15 to the outer periphery of the detection plane range 10R. The plane range of the apparatus increases, and particularly, the frame area provided around the detection plane range 10R and the display area 20R increases, resulting in a fatal problem that miniaturization of the apparatus is hindered.

  On the other hand, in the above-described embodiment, the photodetector 15 is arranged outside the corner of the detection plane range 10R, thereby reducing the number of photodetectors and eliminating the need to use a special photodetector. Therefore, there is an advantage that the manufacturing cost can be reduced, and there is an advantage that the apparatus can be downsized.

  Note that the position detection device and the electro-optical device of the present invention are not limited to the illustrated examples described above, and it is needless to say that various changes can be made without departing from the gist of the present invention. For example, in each of the above embodiments, only one photodetector 15 is provided. However, if the photodetector 15 is arranged at the above-described position defined in the present invention, another photodetector is provided. It may be arranged at an appropriate position.

  Further, the electro-optical panel 20 is not limited to the above-described liquid crystal display panel, and other types of panels such as an organic electroluminescence panel can be used as long as they do not interfere with the principle of the present invention.

1 is a schematic cross-sectional view schematically showing a configuration of a first embodiment of an electro-optical device. The top view which shows a mode that 1st Embodiment was seen from the visual recognition side. FIG. 3 is an exploded perspective view illustrating a main configuration of the first embodiment of the electro-optical device. The top view which shows the positional relationship of the light source for position detection of 1st Embodiment, a light-guide plate, and a photodetector. FIG. 5 is a schematic cross-sectional view schematically showing a configuration of a second embodiment of an electro-optical device. The top view which shows a mode that 2nd Embodiment was seen from the visual recognition side. The disassembled perspective view which shows the main structures of 2nd Embodiment. The top view which shows a mode that 3rd Embodiment was seen from the visual recognition side. The top view which shows a mode that 4th Embodiment was seen from the visual recognition side. The top view which shows a mode that 5th Embodiment was seen from the visual recognition side. The top view which shows a mode that 6th Embodiment was seen from the visual recognition side. The top view which shows a mode that the comparative example was seen from the visual recognition side. The top view which shows a mode that the different comparative example was seen from the visual recognition side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Position detection unit, 11 ... Light source for illumination, 12A, 12B, 12C, 12D ... Light source for position detection, 13 ... Light guide plate, 13a, 13b, 13c, 13d ... Light incident surface, 13s ... Light emission surface, 14 ... Light reflection plate, 15 ... photodetector, 15a ... light receiving unit, 15r ... detectable angle range, 15rs ... detection center axis, 16 ... optical sheet, 20 ... electro-optic panel, 30 ... cover plate, 31 ... surface plate, 31a Opening 31b Opening edge 41 Light source for illumination 43 Light guide plate for illumination L2a, L2b, L2c, L2d Position detection light L4 Illumination light

Claims (10)

A position detection device for optically detecting a plane position of a target object within a detection plane range configured in a polygonal shape,
A first position detection light source for emitting first position detection light;
A second position detection light source that emits second position detection light;
A first light incident surface for incorporating the first position detection light; a second light incident surface for incorporating the second position detection light; and the first light incidence surface and the first light incident surface. A light guide plate having a light exit surface that emits the first position detection light and the second position detection light that are adjacent to, intersect with, and propagate through the light incident surface;
The light guide plate includes a light receiving portion that is disposed on an emission side of the first position detection light and the second position detection light and is directed to the detection plane range, and is disposed outside a corner portion of the detection plane range. Adjacent photodetectors;
A position detection apparatus comprising:   In the light guide plate, the first light incident surface and the second light incident surface are provided at positions facing each other, and the first position detection light source and the second position detection light source use the light guide plate. The position detection apparatus according to claim 1, wherein the position detection apparatus is disposed at a position facing each other with the sandwiched therebetween.   The position detection device according to claim 1, wherein the detection plane range is configured in a rectangular shape.   A planar shape along the light emitting surface of the light guide plate is formed in a rectangular shape, and the first light incident surface and the second light incident surface are formed on opposite sides of the rectangular shape, respectively. The position detection device according to claim 1.   The apparatus further comprises position information acquisition means for obtaining plane position information of the target object based on detection values of the first position detection light and the second position detection light by the light detector. The position detection device according to any one of 1 to 4. The following configuration for optically detecting the plane position of the target object within the detection plane range configured in a polygonal shape,
(A) a first position detection light source that emits first position detection light;
(B) a second position detection light source that emits second position detection light;
(C) a first light incident surface that incorporates the first position detection light, a second light incident surface that incorporates the second position detection light, a first light incidence surface; A light guide plate having a light exit surface that is adjacent to and intersects with the second light incident surface and that emits the first position detection light and the second position detection light propagating through the interior;
(D) A light receiving portion that is disposed on an emission side of the first position detection light and the second position detection light with respect to the light guide plate and is directed to the detection plane range, and a corner portion of the detection plane range A photodetector, located adjacent to the outside of the
A position detecting device having
An electro-optic that includes a display region that at least partially overlaps the detection plane range, and is disposed on the opposite side to the traveling direction of the first position detection light and the second position detection light with respect to the photodetector. A panel,
An electro-optical device comprising:   The electro-optical panel is disposed between the light guide plate and the photodetector, and the display area is configured to transmit the first position detection light and the second position detection light. The electro-optical device according to claim 6. In the electro-optical panel, an electro-optical material is disposed between a first substrate and a second substrate, and the first substrate has a substrate protruding portion that protrudes from the outer shape of the second substrate. Provided,
The electro-optical device according to claim 6, wherein the photodetector is disposed so as to overlap the substrate overhanging portion in a planar manner. The electro-optical panel is a liquid crystal panel;
The electro-optical device includes an illumination light source, a light incident surface that takes in illumination light emitted from the illumination light source, and a light exit surface that is adjacent to and intersects with the light incident surface, and is flat with the electro-optical panel. The electro-optical device according to claim 6, further comprising: an illumination light guide plate that is arranged in an overlapping manner.   The apparatus further comprises position information acquisition means for obtaining plane position information of the target object based on detection values of the first position detection light and the second position detection light by the light detector. The electro-optical device according to any one of 6 to 9.

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