JP2010198548A - Position detector, electrooptical device, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical position detector with a simple constitution and to enable it to detect positions of a plurality of objects in a detection region. <P>SOLUTION: This position detector includes a first light source (12A) for position detection for emitting first position detection light to the detection region (10R), a second light source (12B) for position detection for emitting second position detection light to the detection region, and a plurality of first photodetectors (15A and 15B) that are disposed correspondingly to a first region (10RA) and a second region (10RB) obtained by dividing the detection region into at least two, and detect lights produced by reflection of the first and second position detection lights by an object (Ob) in the corresponding first region and second region, respectively. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technical field of, for example, a position detection device that detects a position of a target object, an electro-optical device such as a liquid crystal device including such a position detection device, and an electronic apparatus including such an electro-optical device.

  As this type of position detection device, various types of touch panels such as a resistive film type, an ultrasonic type, a capacitance type, and an optical type are known. For example, Patent Documents 1 and 2 relate to an optical touch panel that is used in an overlapping manner on a display screen of an electro-optical device such as a liquid crystal device, and enables coordinate input without degrading the image quality of the display screen. A technique for reducing the size is disclosed.

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, and the structure is complicated. There is a technical problem that it becomes. In addition, in the above-described optical touch panel, depending on the configuration, there is a technical problem that when a plurality of objects are simultaneously arranged in the detection region, the plurality of objects may be detected as one object. is there.

  The present invention has been made in view of the above-described problems, for example, has a simple configuration, and can detect the positions of a plurality of target objects in a detection region, and an electric device equipped with such a position detection device. An object is to provide an optical device and an electronic apparatus including such an electro-optical device.

  In order to solve the above-described problem, the position detection apparatus of the present invention is a position detection apparatus that detects the position of a target object in a detection area, and the first position detection light that emits first position detection light to the detection area. A position detection light source, a second position detection light source that emits second position detection light to the detection area, and a first area and a second area obtained by dividing the detection area into at least two parts, respectively. A plurality of first photodetectors that detect the light reflected by the target object in the corresponding first region and second region, respectively. .

  According to the position detection apparatus of the present invention, during the operation, the first and second position detection lights are incident on the detection region from the first and second position detection light sources. The “detection region” according to the present invention is a region where the position of the target object is to be detected, and is defined as a planar region or a spatial region. Further, the first and second position detection lights may be emitted directly to the detection area, or indirectly to the detection area, for example, emitted to the detection area via the light guide plate. It may be emitted. For example, when a target object such as a finger or a touch pen is arranged in the detection area, the first and second position detection lights incident on the detection area are reflected by the target object, and the reflected light is reflected by the first light. It is detected by a photodetector. The distance at which each of the first and second position detection lights reflected by the target object propagates from the position detection light source to the target object (that is, the first position detection light is the target from the first position detection light source). The distance that propagates to the object and the distance that the second position detection light propagates from the second position detection light source to the target object) vary depending on the position of the target object in the detection region. Therefore, the first and second position detection lights reflected by the target object are detected by the first photodetector, and based on the detected detection value (for example, the light amount or intensity of each position detection light). For example, it is possible to derive data such as the light amount ratio and phase difference between the first and second position detection lights, and to acquire position information of the target object from this data (that is, the position of the target object in the detection region). Can be detected).

  Particularly in the present invention, the plurality of first photodetectors are provided corresponding to each of the first region and the second region obtained by dividing the detection region into at least two parts, and the corresponding first region and second region are provided. , The first and second position detection lights respectively detect the light reflected by the target object.

  For example, the first photodetector is provided in correspondence with each of the two first and second regions obtained by dividing the detection region into two, and the first photodetector in the corresponding first and second regions. The second position detection light detects the light reflected by the target object. That is, one of the two first photodetectors provided corresponding to each of the two first and second regions obtained by dividing the detection region into two first photodetectors. Detects light from a corresponding one of the two first and second regions, and the other first photodetector detects from the corresponding one of the two first and second regions. To detect light. Thus, for example, in the case where two target objects are simultaneously disposed in each of the two first and second regions in the detection area, the positions of the two target objects are determined by the two first photodetectors. Can be reliably detected. In other words, for example, erroneous detection of two target objects arranged in the detection region as one object can be reduced.

  Therefore, for example, when a plurality of target objects are simultaneously arranged one by one in each of a plurality of areas obtained by dividing the detection area, the positions of the plurality of target objects are determined by the plurality of first photodetectors. It can be detected reliably (that is, so-called “multi-point detection” is possible in the detection region). In other words, for example, erroneous detection of a plurality of target objects arranged in the detection area as one object can be reduced.

  That is, in the present invention, in particular, the detection area is divided into a plurality of areas, and the first photodetector is provided for each area, so that the first and second position detection lights are reflected by the target object in the detection area. The detected light is shared by the plurality of first photodetectors for each region. Accordingly, it is possible to reduce erroneous detection of a plurality of target objects arranged in the detection region as one object.

  Further, in the present invention, the first and second position detection lights are emitted from the first and second position detection light sources to the detection region, and the light reflected by the target object is, for example, two or four. It has the simple structure of detecting with the some 1st photodetector. Therefore, the number of light sources, photodetectors, etc. is small and low compared to the case where a large number of light sources and photodetectors or optical switches or light guide structures corresponding to the resolution are arranged around the detection area. Cost reduction and low power consumption can be achieved.

  As described above, the position detection device of the present invention has a simple configuration and can detect the positions of a plurality of target objects in the detection region.

  In one aspect of the position detection apparatus of the present invention, the plurality of first photodetectors are arranged so that the respective photodetectable areas do not overlap with each other in the detection area.

  According to this aspect, since the light detection regions of the plurality of first photodetectors do not overlap with each other, the detection accuracy for detecting the position of the target object by each of the plurality of first photodetectors is increased. Can do. That is, each of the plurality of first photodetectors detects only light from a corresponding region (that is, light from a non-corresponding region is hardly mixed or not at all). The position of the target object can be detected with high accuracy.

  The “photodetectable region” according to the present invention is a planar region or a spatial region where the photodetector can detect light, in other words, a planar region or a spatial region where the light receiving element included in the photodetector can receive light. It is.

  In another aspect of the position detection apparatus of the present invention, the position detection apparatus includes position information acquisition means for acquiring position information of the target object based on detection values detected by the plurality of first photodetectors.

  According to this aspect, the position information acquisition unit obtains data such as a light amount ratio and a phase difference for the first and second position detection lights based on the detection value detected by the first photodetector, for example. The position information in the first direction (for example, the direction from the first position detection light source to the second position detection light source) in the detection region is obtained from this data. Therefore, the position of the target object in the detection area can be detected. Note that the position information acquisition unit includes a processor, a memory, and the like, for example. The position information acquisition unit does not need to be included in the position detection device itself, and may be configured by, for example, a control unit including, for example, an MPU (Micro Processing Unit) or an electronic circuit in an electronic device in which the position detection device is mounted. . However, since the position detection device itself includes the position information acquisition means, there is also an advantage that the acquired position information can be output as it is to an electronic device to be mounted.

  In another aspect of the position detection apparatus of the present invention, each of the plurality of first photodetectors has an adjustment member that adjusts each of the photodetectable regions.

  According to this aspect, the first photodetector has an adjusting member such as a slit or a lens, and the photodetectable region of the first photodetector includes, for example, a corresponding region. It is adjusted by the adjusting member. Therefore, each of the plurality of first photodetectors can surely detect light from the corresponding region.

  In another aspect of the position detection apparatus of the present invention, a first light incident surface on which the first position detection light is incident, a second light incident surface on which the second position detection light is incident, and A light guide plate having a light exit surface that intersects the first and second light incident surfaces and emits the incident first and second position detection lights to the detection region is provided.

  According to this aspect, the first and second position detection lights emitted from the first and second position detection light sources can be reliably guided to the detection region by the light guide plate.

  In the aspect including the light guide plate described above, the plurality of first photodetectors are arranged along the first side of the light guide plate, and each of the plurality of first photodetectors has a light detectable region. The adjusting member may be adjusted to extend in a direction intersecting the first side.

  In this case, for example, when a plurality of target objects are arranged along the direction intersecting the first side of the light guide plate in the detection region, the plurality of target objects are erroneously detected as one object. Can be reduced.

  In the aspect including the light guide plate described above, the plurality of first photodetectors may be disposed on the light exit surface side with respect to the light guide plate.

  In this case, the plurality of first photodetectors can directly detect the light reflected by the target object from the first and second position detection lights without passing through the light guide plate.

  In the aspect including the light guide plate described above, the plurality of first photodetectors may be disposed on the opposite side of the light output surface with respect to the light guide plate.

  In this case, the degree of freedom for arranging the plurality of first detectors can be increased, which is advantageous in practice.

  In another aspect of the position detection apparatus of the present invention, the detection area is provided corresponding to each of a third area and a fourth area obtained by dividing the detection area into at least two division ranges different from the first area and the second area. And a plurality of second photodetectors for detecting the lights reflected by the target object in the corresponding third region and fourth region, respectively.

  According to this aspect, it is possible to more reliably reduce erroneous detection of a plurality of target objects arranged in the detection region as one object. For example, even when two target objects are simultaneously disposed in the first region, the first region overlaps the two third and fourth regions, and the two target objects are different from each other in the third and fourth regions. If arranged in the four areas, the positions of the two target objects can be reliably detected by the two second photodetectors provided corresponding to the third and fourth areas.

  In another aspect of the position detection apparatus of the present invention, the plurality of first photodetectors and the plurality of second photodetectors are driven so as to detect light at different timings.

  According to this aspect, it is possible to more reliably reduce erroneous detection of a plurality of target objects arranged in the detection region as one object.

  In order to solve the above problems, an electro-optical device according to the present invention includes the above-described position detection device according to the present invention (including various aspects thereof) and an electro-optical panel that at least partially overlaps the detection region. And comprising.

  According to the electro-optical device of the present invention, since the position detection device described above is included, for example, the cost and power consumption can be reduced, and the positions of a plurality of target objects in the display region of the electro-optical panel are achieved. Can be detected.

  In order to solve the above-described problems, an electronic apparatus according to the present invention includes the above-described electro-optical device according to the present invention (including various aspects thereof).

  According to the electronic apparatus of the present invention, since the electro-optical device of the present invention described above is provided, for example, the cost and power consumption can be reduced and the positions of a plurality of target objects in the display region can be achieved. Can detect various electronic devices such as a car navigation system, a TV, a mobile phone, an electronic notebook, a word processor, a viewfinder type or a monitor direct-view type video tape recorder, a workstation, a videophone, a POS terminal, and a touch panel. In addition, as an electronic apparatus of the present invention, for example, an electrophoretic device such as electronic paper, an electron emission device (Field Emission Display and Conduction Electron-Emitter Display), and a display device using these electrophoretic device and electron emission device Is also possible.

  The operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

It is a disassembled perspective view which shows the whole structure of the liquid crystal device which concerns on 1st Embodiment. It is sectional drawing which shows typically the whole structure of the liquid crystal device which concerns on 1st Embodiment. It is a top view which shows typically the structure of the position detection apparatus which concerns on 1st Embodiment. It is a top view which shows typically the position detection apparatus which concerns on a comparative example. It is a top view which shows typically the position detection apparatus which concerns on 2nd Embodiment. It is a top view which shows typically the position detection apparatus which concerns on 3rd Embodiment. It is a top view which shows typically the position detection apparatus which concerns on 3rd Embodiment. It is a top view which shows typically the position detection apparatus which concerns on 4th Embodiment. It is a schematic diagram which shows the structure of the photodetector which concerns on 4th Embodiment. It is a top view which shows typically the position detection apparatus which concerns on 5th Embodiment. It is sectional drawing which shows typically arrangement | positioning of the photodetector in the position detection apparatus which concerns on 6th Embodiment. 1 is a perspective view illustrating a configuration of a car navigation system as an example of an electronic apparatus to which an electro-optical device according to the invention is applied.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, a liquid crystal device is taken as an example of an electro-optical device including the position detection device of the present invention.

<First Embodiment>
A first embodiment of the present invention will be described with reference to FIGS.

  First, the overall configuration of the liquid crystal device according to the present embodiment will be described with reference to FIGS. 1 and 2.

  FIG. 1 is an exploded perspective view showing the overall configuration of the liquid crystal device according to the present embodiment. FIG. 2 is a cross-sectional view schematically showing the overall configuration of the liquid crystal device according to the present embodiment.

  1 and 2, the liquid crystal device 100 according to the present embodiment includes a liquid crystal panel 20, an illumination unit 40, a position detection unit 10, a light reflection plate 14, an optical sheet 16, and photodetectors 15A and 15B. And. The position detection unit 10 and the photodetectors 15A and 15B constitute an example of the “position detection device” according to the present invention. That is, the position detection device according to the present embodiment includes the position detection unit 10 and the photodetectors 15A and 15B. Further, as described later, the position detection apparatus according to the present embodiment has a planar position of the target object Ob in the detection plane area 10R as an example of the “detection area” according to the present invention that matches the display area 20R of the liquid crystal panel 20. Can be detected. However, the detection plane area 10R only needs to overlap with at least a part of the display area 20R in a plane, and may not completely coincide with the display area 20R.

  The liquid crystal panel 20 is an active matrix drive type display panel that drives a liquid crystal element by a switching element such as a TFT (Thin Film Transistor), and is configured to display an image in the display region 20R. The liquid crystal panel 20 is an example of the “electro-optical panel” according to the present invention.

  The liquid crystal panel 20 is a transmissive liquid crystal panel having a structure in which a liquid crystal layer 24 (see FIG. 2) is sandwiched between a first substrate 21 and a second substrate 22 each formed of a light-transmitting material such as glass, for example. It is configured. The first substrate 21 and the second substrate 22 are bonded to each other by a frame-shaped sealing material 23 (see FIG. 2). A liquid crystal layer 24 is provided in a region defined by the frame-shaped sealing material 23. In the present invention, the liquid crystal panel 20 is not limited to a specific configuration, and may employ various known configurations.

  More specifically, the first substrate 21 of the liquid crystal panel 20 is provided with a substrate overhanging portion 21 t that projects from the outer shape of the second substrate 22 to the periphery. An electronic component 25 including, for example, a drive circuit for driving the liquid crystal panel 20 or the like, for example, flexible, is provided on the substrate overhanging portion 21t (more precisely, the surface of the substrate overhanging portion 21t on the second substrate 22 side). A wiring member 26 such as a wiring board (FPC: Flexible Printed Circuit) is mounted. However, only the wiring member 26 of the electronic component 25 and the wiring member 26 may be mounted on the board extension portion 21t, or neither the electronic component 25 nor the wiring member 26 may be mounted. . A polarizing plate (not shown) may be disposed on the outer surface side of the first substrate 21 and the second substrate 22 as necessary.

  As shown in FIG. 2, on the viewing side (that is, the operation side) of the liquid crystal panel 20, a surface mount plate 30 having a light transmitting property (or a light transmitting property) is disposed. Photodetectors 15A and 15B, which will be described later, are arranged on the outer surface of the front panel 30 (that is, the surface opposite to the liquid crystal panel 20, that is, the surface on the viewing side). Further, on the outer surface side of the cover plate 30, a surface plate 31 (a two-dot chain line in FIG. Is shown). The surface plate 31 is provided with an opening 31a that exposes the display area 20R of the liquid crystal panel 20 (in other words, the detection plane area 10R of the position detection device according to the present embodiment) of the front panel 30.

  1 and 2, the illumination unit 40 includes an illumination light source 41 and an illumination light guide plate 43, and can function as a backlight that irradiates the liquid crystal panel 20 with the illumination light L4. It is configured.

  The illumination light source 41 is composed of a light emitting element such as an LED (Light Emitting Diode), for example, and emits, for example, white irradiation light L4 in response to a drive signal output from a drive circuit (not shown). In the present embodiment, a plurality of illumination light sources 41 are arranged along a light incident surface (or light incident end surface) 43 a that is one side surface of the illumination light guide plate 43. During the operation of the liquid crystal device 100, the irradiation light L4 from the illumination light source 41 enters the light incident surface 43a of the illumination light guide plate 43.

  The illumination light guide plate 43 is made of a translucent material, and irradiates light L4 from the illumination light source 41 incident on the light incident surface 43a from the light emitting surface 43s on the side where the liquid crystal panel 20 is disposed. It functions as a light guide that emits and leads to the liquid crystal panel 40.

  The position detection unit 10 constitutes a position detection apparatus according to this embodiment together with photodetectors 15A and 15B described later. The position detection unit 10 includes position detection light sources 12A, 12B, 12C and 12D, and a light guide plate 13.

  The position detection light sources 12A to 12D are configured by light emitting elements such as LEDs, for example, and emit position detection lights L2a, L2b, L2c, and L2d that are, for example, infrared rays in accordance with a drive signal output from a drive circuit (not shown). The position detection light is not particularly limited, but it is preferably one that can be detected separately from external light by signal processing or the like, and the light emission mode is different by changing the visible light from the wavelength distribution or by modulation such as blinking. It is preferable. 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 preferable to use infrared rays with high reflectivity on the surface of the human body (particularly near infrared rays close to the confectionery light region, for example, near 850 nm in wavelength).

  Each of the position detection light sources 12 </ b> A to 12 </ b> D is disposed at each of the four corners of the light guide plate 13 so that each light emitting surface faces the center of the light guide plate 13.

  More specifically, the light source 12A for position detection is arranged so that the light emitting surface thereof faces the light incident surface 13va formed at the corner located between the side surface 13a and the side surface 13d of the light guide plate 13. The position detection light source 12B is disposed so that the light emitting surface thereof faces the light incident surface 13vb formed at the corner located between the side surface 13a and the side surface 13b of the light guide plate 13, and the position detection The light source 12 </ b> C is disposed so as to face the light incident surface 13 vc formed at the corner located between the side surface 13 b and the side surface 13 c of the light guide plate 13, and the position detection light source 12 </ b> D is disposed on the light guide plate 13. It arrange | positions so that the light-incidence surface 13vd formed in the corner | angular part located between the side surface 13c and the side surface 13d may be opposed. During operation of the liquid crystal device 100, the position detection light L2a from the position detection light source 12A is incident on the light incident surface 13va of the light guide plate 13, and the position detection light L2b from the position detection light source 12B is incident on the light incident surface of the light guide plate 13. The position detection light L2c from the position detection light source 12C is incident on the light incident surface 13vc of the light guide plate 13, and the position detection light L2d from the position detection light source 12D is incident on the light incident surface 13vd of the light guide plate 13. Incident. Therefore, the position detection lights L2a to L2d are gradually emitted from the light emission surface 13s along the propagation directions while propagating through the light guide plate 13 in different directions.

  The light guide plate 13 is made of a translucent material such as polycarbonate or acrylic resin. In the present embodiment, the light guide plate 13 has a rectangular shape in plan view and is configured in a flat plate shape as a whole. The above-described position detection light sources 12A to 12D are provided on the light incident surfaces 13va to 13vd formed at the four corners of the light guide plate 13, respectively.

  The light emitting surface 13s of the light guide plate 13 or the light reflecting surface 13t, which is the back surface opposite to the light emitting surface 13s, is provided with a surface uneven structure, a prism structure, a scattering layer, etc. (not shown). The light propagating through the light incident surfaces 13va to 13vd of the light guide plate 13 is gradually deflected as it proceeds in the propagation direction, and is emitted from the light emitting surface 13s. As a result, the position detection lights L <b> 2 a to L <b> 2 d are emitted in a planar shape from the light exit surface 13 s of the light guide plate 13 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 13va toward the light incident surface 13vc, the side surface 13c, and the side surface 13b.

  The position detection lights L2a to L2d emitted in a planar shape from the light emitting surface 13s of the light guide plate 13 are transmitted through the irradiation light guide plate 43, the optical sheet 16, the liquid crystal panel 20, and the cover plate 30 to visually recognize the cover plate 30. The light is emitted from the entire detection plane region 10R on the side (that is, the operation side, that is, the side where the target object Ob is disposed). When the target object Ob such as a finger is disposed on the viewing side of the front mounting plate 30, the position detection lights L2a to L2d emitted from the detection plane region 10R are reflected by the target object Ob, and part of the reflected light is described later. Is detected by the photodetector 15A or 15B.

  The light reflection plate 14 is made of, for example, a reflection sheet, and is disposed so as to face the light reflection surface 13 t of the light guide plate 13. The light reflecting plate 14 reflects the light emitted from the light reflecting surface 13 t of the light guide plate 13 and returns it to the inside of the light guide plate 13.

  The optical sheet 16 is disposed on the light exit surface 13s side of the light guide plate 13 (in this embodiment, on the light exit surface 43s side of the illumination light guide plate 43). The optical sheet 16 is a light diffusing plate for making the position detection lights L2a to L2d and the illumination light L4 uniform, a light collecting plate such as a prism sheet for enhancing the directivity of the position detection lights L2a to L2d and the illumination light L4, and the like. This is an optical sheet. 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 13 of the light guide plate 13 (angle with respect to the normal direction of the light emission surface 13s) are 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 (that is, the operation side) so that highly accurate and stable position detection is possible.

  The photodetectors 15 </ b> A and 15 </ b> B are an example of “a plurality of first photodetectors” according to the present invention, and are arranged on the outer surface of the above-described cover plate 30. The photodetectors 15A and 15B include light receiving elements such as photodiodes, for example, and detect the intensities of the position detection lights L2a to L2d (that is, the position detection lights L2a to L2d reflected by the target object Ob) described above. It is configured to be possible. For example, if the position detection lights L2a to L2d are infrared rays, the photodetectors 15A and 15B are also configured to include a light receiving element having sensitivity to infrared rays. By selecting the light receiving sensitivities of the photodetectors 15A and 15B so that the wavelength regions of the position detection lights L2a to L2d can be selectively detected, the influence of other light such as external light can be reduced. Each of the photodetectors 15A and 15B has an adjustment member such as a lens or a slit that adjusts a photodetectable region where light can be detected. In the present embodiment, as will be described in detail later with reference to FIG. 3, the photodetectable region 15AR of the photodetector 15A has a detection plane region 10R along the side surface 13b along the direction along the side surface 13b (that is, the Y direction in the drawing). The two subregions 10RA and 10RB divided into two are adjusted to include one partial region 10RA, and the photodetectable region 15BR of the photodetector 15B is adjusted to include the two partial regions 10RA. And 10RB are adjusted so as to include the other partial region 10RB. When the liquid crystal device 100 is operated, if the target object Ob such as a finger is disposed in the partial area 10RA of the detection plane area 10R, the position detection lights L2a to L2d emitted from the position detection unit 10 are targets in the partial area 10RA. Reflected by the object Ob, a part of the reflected light is detected by the photodetector 15A. On the other hand, when the target object Ob such as a finger is arranged in the partial area 10RB of the detection plane area 10R, the position detection lights L2a to L2d emitted from the position detection unit 10 are reflected by the target object Ob in the partial area 10RB. A part of the reflected light is detected by the photodetector 15B.

  Next, an acquisition method for acquiring the plane position information (position coordinates) of the target object Ob in the partial region 10RA based on the detection value detected by the photodetector 15A will be described. The acquisition method for acquiring the planar position information of the target object Ob in the partial area 10RB based on the detection value detected by the photodetector B is based on the detection value detected by the photodetector A in the partial area 10RA. This is almost the same as the acquisition method for acquiring the plane position information of the target object Ob.

  There are various methods for obtaining the plane 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. There is a method of obtaining position coordinates in a direction connecting two corresponding light sources by obtaining the propagation distance of both position detection lights from the ratio.

  More specifically, a case where the first position detection light source 12A and the third position detection light source 12C are used as two position detection light sources will be described as an example. The control amount (for example, current amount), the conversion coefficient, and the emitted light amount are set to Ia, k, and Ea, respectively, and the control amount (for example, current amount), the conversion coefficient, and the emitted light amount for the second position detection light source 12C are respectively set to Ic, k, and Ea. Assuming Ec, Ea = k · Ia and Ec = k · Ic. Further, if the attenuation coefficient and the detected light amount of the position detection light L2a are fa and Ga, respectively, and the attenuation coefficient and the detected light amount of the position detection light L2c are fc and Gc, respectively, Ga = fa · Ea = fa · k · Ia, Gb = fc · Ec = fc · k · Ic.

  Therefore, if Ga / Gc, which is the ratio of the detected light amounts of the two position detection lights, can be detected by the photodetector 15A, Ga / Gc = (fa · Ea) / (fc · Ec) = (fa / fc) · Since (Ia / Ic) is obtained, if the values corresponding to the ratio Ea / Ec of the emitted light quantity and the ratio Ia / Ic of the control amount are known, the ratio fa / fc 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, by setting this correlation in advance, the plane position information (the first position of the target object Ob) Position coordinates in the direction from the position detection light source 12A to the third position detection light source 12C).

  As a method for obtaining the above-described attenuation coefficient ratio fa / fc, for example, the first position detection light source 12A and the third position detection light source 12C are blinked in opposite phases (for example, rectangular wave or sine wave drive). The signal is operated so as to have a phase difference of 180 degrees between each other at a frequency at which the phase difference caused by the difference in propagation distance is negligible, and then 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 / Gc becomes 0). The amount Ic is controlled, and the damping coefficient ratio (fa / fc) described above is derived from the control amount Ic = Im · (fa / fc) at this time.

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

  In the present embodiment, the position information of the target object Ob in the direction from the first position detection light source 12A to the third position detection light source 12C is the first position detection light source 12A and the third position detection light source 12C. And can be obtained by driving them in opposite phases. Similarly, the positional information of the target object Ob in the direction from the second position detection light source 12B to the fourth position detection light source 12D includes the third position detection light source 12C and the fourth position detection light source 12D. Can be obtained by driving them in opposite phases. Therefore, the position coordinate of the target object Ob in the partial region 10RA can be acquired by sequentially performing the detection operations in the two directions in the control system.

  Further, the position detection light source 12A and the position detection light source 12D are driven in phase as the first position detection light source, and the position detection light source 12B and position detection light source 12C are driven in phase as the second position detection light source. Then, when the first position detection light source and the second position detection light source are driven and detected in mutually opposite phases, the position detection light source 12A and the position detection light source 12B are detected by the first position detection. The position detection light source 12C and the position detection light source 12D are driven in phase as the second position detection light source, and the first position detection light source and the second position detection light source are driven in phase. The position coordinates on the plane of the target object Ob can also be acquired by switching the detection in the opposite phase and detecting the coordinates sequentially. According to the configuration in which a plurality of such position detection light sources are turned on simultaneously, for example, the emitted light quantity distribution in the direction from the first position detection light source to the opposing second position detection light source or in the opposite direction ( (Brightness / inclination distribution of position detection light) is preferably obtained in a wider range than a configuration in which one position detection light source is turned on, so that more accurate position detection is possible.

  The above-described acquisition of the planar position information of the target object Ob is performed by position information acquisition means configured by, for example, a microprocessor included as a part of the electronic component 25. The position information acquisition means may be configured to acquire plane position information by executing predetermined software (operation program), or by performing predetermined processing using hardware such as a logic circuit, for example. It is good also as a structure which acquires plane position information. Further, such position information acquisition means may be incorporated as a part of the liquid crystal device 100 or may be configured inside an electronic apparatus in which the liquid crystal 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, for example, as a method for acquiring the plane position information, 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 inside the light guide plate 13 is also conceivable. In this case, the plane position information of the target object Ob can be calculated according to the relationship between the magnitude of the phase difference and the difference in the propagation distance.

  As described above, according to the position detection device according to the present embodiment, the position detection lights L2a to L2d reflected by the target object Ob arranged in the partial region 10RA are detected by the photodetector 15A. Based on the detected value, for example, data such as a light amount ratio and a phase difference of the position detection lights L2a to L2d can be derived, and plane position information in the partial region 10RA of the target object Ob can be acquired from this data (ie, The plane position of the target object Ob in the partial area 10RA in the detection plane area 10R can be detected). Similarly, according to the position detection device according to the present embodiment, the detection detected by detecting the position detection lights L2a to L2d reflected by the target object Ob arranged in the partial region 10RB by the photodetector 15B. Based on the value, for example, data such as a light amount ratio and a phase difference of the position detection lights L2a to L2d can be derived, and plane position information in the partial region 10RB of the target object Ob can be acquired from this data (that is, detection) The plane position of the target object Ob in the partial area 10RB of the plane area 10R can be detected). Thus, according to the position detection apparatus according to the present embodiment, the planar position of the target object Ob in the detection plane region 10R (that is, the partial regions 10RA and 10RB) can be detected.

  Next, the configuration of the position detection apparatus according to the present embodiment will be described with reference to FIG.

  FIG. 3 is a plan view schematically showing the configuration of the position detection apparatus according to the present embodiment.

  In FIG. 3, in the present embodiment, in particular, the photodetectors 15A and 15B are provided corresponding to partial regions 10RA and 10RB obtained by dividing the detection plane region 10R into two, respectively. The partial region 10RA is an example of the “first region” according to the present invention, and the partial region 10RB is an example of the “second region” according to the present invention.

  Specifically, the photodetector 15A is provided corresponding to the partial region 10RA in the detection plane region 10R, and the photodetectable region 15AR of the photodetector 15A includes the partial region 10RA and the partial region 10RB. For example, it is adjusted by an adjustment member such as a lens. The photodetector 15B is provided corresponding to the partial region 10RB in the detection plane region 10R, and the photodetectable region 15BR of the photodetector 15B includes the partial region 10RB and does not include the partial region 10RA. For example, it is adjusted by an adjusting member such as a lens. In other words, the photodetectors 15A and 15B are such that the photodetectable region 15AR includes the partial region 10RA, the photodetectable region 15BR includes the partial region 10RB, and the photodetectable regions 15AR and 15BR do not overlap each other. So that it is arranged.

  Therefore, the reflected light Lr1 from the target object Ob1 such as a finger or a touch pen arranged in the partial area 10RA in the detection plane area 10R (that is, the position detection lights L2a to L2d emitted from the position detection unit 10 are the target object Ob1). Light reflected by the target object Ob2 such as a finger or a touch pen disposed in the partial area 10RB of the detection plane area 10R (that is, the light reflected by the light detector 15A). The light detected by the target object Ob2 of the position detection lights L2a to L2d emitted from the position detection unit 10 can be detected by the photodetector 15B. That is, particularly in the present embodiment, the photodetector 15A detects the reflected light Lr1 from the corresponding partial region 10RA among the two partial regions 10RA and 10RB constituting the detection plane region 10R, and detects the photodetector 15B. Detects the reflected light Lr2 from the other partial area 10RB corresponding to the two partial areas 10RA and 10RB constituting the detection plane area 10R.

  Therefore, for example, when two target objects Ob1 and Ob2 are simultaneously arranged in each of the two partial regions 10RA and 10RB in the detection plane region 10R, two target objects are detected by the two photodetectors 15A and 15B. Each planar position of Ob1 and Ob2 can be reliably detected. In other words, for example, it is possible to reduce erroneous detection of two target objects Ob1 and Ob2 arranged simultaneously in the detection plane region 10R as one object.

  That is, in this embodiment, in particular, the detection plane area 10R is divided into two partial areas 10RA and 10RB, and a photodetector is provided for each partial area, so that the position detection lights L2a to L2d are 2 in the detection plane area 10R. Detection of light reflected by the two target objects Ob1 and Ob2 is shared by the two photodetectors 15A and 15B for each partial region. Therefore, it is possible to reduce erroneous detection of the two target objects Ob1 and Ob2 arranged in the detection plane region 10R as one object.

  Furthermore, in the present embodiment, the position detection lights L2a to L2d are emitted from the four position detection light sources 12A to 12D to the detection plane region 10R, and the light reflected by the target object Ob is converted into the two photodetectors 15A. And 15B. Therefore, the number of light sources, photodetectors, and the like is small compared to a case where a large number of light sources and photodetectors or optical switches or light guide structures corresponding to the resolution are arranged around the detection plane region 10R. Thus, cost reduction and power consumption can be reduced.

  Next, a position detection apparatus according to a comparative example will be described with reference to FIG.

  FIG. 4 is a plan view schematically showing a position detection device according to a comparative example.

  In FIG. 4, the position detection device according to the comparative example is different from the position detection device according to the present embodiment described above in that a photodetector 15q is provided instead of the photodetectors 15A and 15B according to the present embodiment described above. The other points are configured in substantially the same manner as the position detection device according to the present embodiment described above.

  As shown in FIG. 4, in the position detection device according to the comparative example, the position detection lights L2a to L2d from the four position detection light sources 12A to 12D are detected by the target object Ob (the target object in FIG. 4) in the detection plane region 10R. The light reflected by Ob1 or Ob2) is detected by one photo detector 15q, thereby detecting the plane position of the target object Ob in the detection plane region 10R.

  In the position detection device according to the comparative example configured as described above, when the two target objects Ob1 and Ob2 are simultaneously arranged in the detection plane region 10R, the intensity of the light detected by the photodetector 15q is one. (That is, the photodetector 15q detects the reflected light L1r from the target object Ob1 and the reflected light L2r from the target object Ob2 as reflected light from one target object without distinguishing) The target objects Ob1 and Ob2 are erroneously detected as one target object Ob ′.

  However, according to the present embodiment, as described above, the reflected light Lr1 from the target object Ob1 arranged in one partial region 10RA of the two partial regions 10RA and 10RB constituting the detection plane region 10R is as follows. The reflected light Lr2 detected by the photodetector 15A and reflected from the target object 10RB disposed in the other partial region 10RB is configured to be detected by the photodetector 15B, and thus is disposed in the detection plane region 10R. It is possible to reduce erroneous detection of the two target objects Ob1 and Ob2 as one target object Ob ′.

<Second Embodiment>
A second embodiment of the present invention will be described with reference to FIG. In FIG. 5, the same reference numerals are given to the same components as the components according to the first embodiment shown in FIGS. 1 to 3, and description thereof will be omitted as appropriate.

  FIG. 5 is a plan view schematically showing the position detection apparatus according to the second embodiment.

  In FIG. 5, the position detection device according to the second embodiment is different from the position detection device according to the first embodiment described above in the shapes of the partial regions 10RA and 10RB (in other words, the detection plane region 10R is divided into two parts. The division pattern divided into the regions 10RA and 10RB) and the arrangement of the photodetectors 15A and 15B are different, and the other points are substantially the same as those of the position detection device according to the first embodiment described above.

  In the present embodiment, the light detector 15 </ b> A has a light receiving surface on the side surface 13 c side of the light guide plate 13 in an area corresponding to the corner where the position detection light source 12 </ b> A is provided among the four corners of the light guide plate 13. It is arranged to face. The photodetector 15B is arranged in an area corresponding to the corner where the position detection light source 12C is provided among the four corners of the light guide plate 13 so that the light receiving surface thereof faces the side surface 13a of the light guide plate 13. ing. The photodetectable region 15AR of the photodetector 15A is along a direction in which the detection plane region 10R is obliquely intersected with the side surface 13a (more specifically, the direction from the position detection light source 12A to the position detection light source 12C). It is adjusted to include one partial region 10RA out of the two partial regions 10RA and 10RB divided into two (generally along the line). The photodetectable region 15BR of the photodetector 15B is adjusted to include the other partial region 10RB of the two partial regions 10RA and 10RB. When the liquid crystal device 100 is operated, if the target object Ob1 such as a finger is disposed in the partial area 10RA of the detection plane area 10R, the position detection lights L2a to L2d emitted from the position detection unit 10 are targets in the partial area 10RA. The light is reflected by the object Ob1, and a part of the reflected light Lr1 is detected by the photodetector 15A. On the other hand, when the target object Ob2 such as a finger is disposed in the partial area 10RB in the detection plane area 10R, the position detection lights L2a to L2d emitted from the position detection unit 10 are reflected by the target object Ob2 in the partial area 10RB. A part of the reflected light is detected by the photodetector 15B.

  Therefore, according to the present embodiment, for example, two target objects Ob1 and Ob2 are simultaneously arranged in each of the two partial regions 10RA and 10RB in the detection plane region 10R in substantially the same manner as in the first embodiment described above. In this case, the planar positions of the two target objects Ob1 and Ob2 can be reliably detected by the two photodetectors 15A and 15B. In other words, for example, it is possible to reduce erroneous detection of two target objects Ob1 and Ob2 arranged in the detection plane region 10R as one object.

<Third Embodiment>
A third embodiment of the present invention will be described with reference to FIGS. 6 and 7, the same reference numerals are given to the same components as the components according to the first embodiment shown in FIGS. 1 to 3, and description thereof will be omitted as appropriate.

  6 and 7 are plan views schematically showing the position detection apparatus according to the third embodiment. 6 shows the configuration of the position detection device according to the third embodiment together with the photodetectable regions 15AR and 15BR of the photodetectors 15A and 15B, and FIG. 7 shows the position detection according to the third embodiment. The configuration of the apparatus is shown together with the photodetectable regions 15CR and 15DR of the photodetectors 15C and 15D, respectively.

  6 and 7, the position detection device according to the third embodiment is different from the position detection device according to the first embodiment described above in that it further includes photodetectors 15C and 15D. The configuration is substantially the same as that of the position detection device according to the present embodiment described above.

  As shown in FIG. 6, in the present embodiment, the photodetectors 15A and 15B are disposed on the side surface 13a side of the light guide plate 13 with respect to the detection plane region 10R, as in the first embodiment described above. The photodetectable region 15AR of the photodetector 15A is divided into two parts divided by a first division pattern that divides the detection plane region 10R into two along the side surface 13b (that is, along the Y direction in the drawing). The photodetectable region 15BR of the photodetector 15B is adjusted to include one partial region 10RA of the regions 10RA and 10RB, and the other of the two partial regions 10RA and 10RB divided by the first division pattern It is adjusted to include the partial region 10RB.

  In addition to the photodetectors 15A and 15B, the position detection apparatus according to the present embodiment includes photodetectors 15C and 15D that are driven so as to detect light at timings different from those of the photodetectors 15A and 15B. .

  As shown in FIG. 7, the photodetectors 15C and 15D are arranged on the side surface 13b side of the light guide plate 13 with respect to the detection plane region 10R. The photodetectors 15C and 15D are arranged on the outer surface of the above-described front mounting plate 30 (see FIG. 2), similarly to the photodetectors 15A and 15B. Similarly to the photodetectors 15A and 15B, the photodetectors 15C and 15D include a light receiving element such as a photodiode, and are configured to be able to detect the intensity of the position detection lights L2a to L2d. . The photodetectable region 15CR of the photodetector 15C is divided into two portions divided by a second division pattern that divides the detection plane region 10R into two along the side surface 13c (that is, along the X direction in the drawing). The region 10RC is adjusted to include one partial region 10RC of the regions 10RC and 10RD, and the photodetectable region 15DR of the photodetector 15D is adjusted to include the other partial region 10RD of the two partial regions 10RC and 10RD. Has been. In other words, the photodetector 15C is provided corresponding to the partial region 10RC in the detection plane region 10R, and the photodetectable region 15CR of the photodetector 15C includes the partial region 10RC and includes the partial region 10RD. For example, adjustment is performed by an adjustment member such as a lens. The photodetector 15D is provided corresponding to the partial region 10RD in the detection plane region 10R, and the photodetectable region 15DR of the photodetector 15D includes the partial region 10RD and does not include the partial region 10RC. For example, it is adjusted by an adjusting member such as a lens. In other words, the photodetectors 15C and 15D are such that the photodetectable region 15CR includes the partial region 10RC and the photodetectable region 15DR includes the partial region 10RD, and the photodetectable regions 15CR and 15DR do not overlap each other. So that it is arranged. The partial region 10RC is an example of the “third region” according to the present invention, and the partial region 10RD is an example of the “fourth region” according to the present invention.

  That is, the photodetectors 15C and 15D are divided by a second division pattern different from the first division pattern related to the photodetectors 15A and 15B (that is, the division pattern that divides the detection plane region 10R into the partial regions 10RA and 10RB). The partial regions 10RC and 10RD are provided in correspondence with each other. Therefore, the reflected light Lr3 from the target object Ob3 such as a finger or a touch pen disposed in the partial area 10RC in the detection plane area 10R (that is, the position detection lights L2a to L2d emitted from the position detection unit 10 are the target object Ob3). The light reflected by the target object Ob3 such as a finger or a touch pen disposed in the partial area 10RD of the detection plane area 10R (that is, the light reflected by the object 15b) It is possible to detect the position detection lights L2a to L2d emitted from the position detection unit 10 by the target object Ob4) by the photodetector 15D.

  Therefore, erroneous detection of a plurality of target objects arranged in the detection plane region 10R as one object can be more reliably reduced. For example, even when two target objects Ob3 and Ob4 (see FIG. 7) are simultaneously arranged in the partial region 10RB (see FIG. 6), the partial region 10RB overlaps the two partial regions 10RC and 10RD, If the two target objects Ob3 and Ob4 are arranged in different partial regions 10RC and 10RD, the two target objects Ob3 and Ob4 are detected by the photodetectors 15C and 15D provided corresponding to the partial regions 10RC and 10RD, respectively. Each position can be reliably detected.

<Fourth embodiment>
A fourth embodiment of the present invention will be described with reference to FIG. In FIG. 8, the same components as those in the first embodiment shown in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  FIG. 8 is a plan view schematically showing a position detection device according to the fourth embodiment.

  In FIG. 8, the position detection device according to the fourth embodiment further includes photodetectors 15 dA, 15 dB, 15 dC, and 15 dD instead of the photodetectors 15 A and 15 B, and the position detection according to the first embodiment described above. Unlike the apparatus, the other points are substantially the same as those of the position detection apparatus according to the first embodiment described above.

  The photodetectors 15dA to 15dD are arranged on the side surface 13a side of the light guide plate 13 with respect to the detection plane region 10R, and are arranged along the side surface 13a (that is, along the X direction in the drawing). The photodetectors 15dA to 15dD are arranged on the outer surface of the above-described cover plate 30 (see FIG. 2), similarly to the photodetectors 15A and 15B in the first embodiment described above. Like the photodetectors 15A and 15B in the first embodiment described above, the photodetectors 15dA to 15dD are configured to include light receiving elements such as photodiodes, and can detect the intensity of the position detection lights L2a to L2d. It is comprised so that it may become. The photodetectable region 15dAR of the photodetector 15dA has four partial regions 10RdA, 10RdB obtained by dividing the detection plane region 10R into four along the direction along the side surface 13b (that is, along the Y direction in the drawing). 10 RdC and 10 RdD are adjusted to include the partial region 10 RdA, and the photodetectable region 15 dBR of the photodetector 15 dB is adjusted to include the partial region 10 RdB of the four partial regions 10 RdA, 10 RdB, 10 RdC, and 10 RdD. The photodetectable region 15dCR of the photodetector 15dC is adjusted to include the partial region 10RdC among the four partial regions 10RdA, 10RdB, 10RdC, and 10RdD, and the photodetectable region 15dDR of the photodetector 15dD is These four partial regions 10RdA, 10RdB, 10RdC and It is adjusted so as to include a portion area 10RdD of 0RdD. In other words, the photodetector 15dA is provided corresponding to the partial region 10RdA in the detection plane region 10R, and the photodetectable region 15dAR of the photodetector 15dA includes the partial region 10RdA and the partial region 10RdB, It is adjusted by an adjusting member to be described later so as not to include the region 10RdC and the partial region 10RdD. The photodetector 15dB is provided corresponding to the partial region 10RdB in the detection plane region 10R, and the photodetectable region 15dBR of the photodetector 15dB includes the partial region 10RdB, the partial region 10RdA, the partial region 10RdC, and It is adjusted by an adjusting member to be described later so as not to include the partial region 10RdD. The photodetector 15dC is provided corresponding to the partial region 10RdC in the detection plane region 10R. The photodetectable region 15dCR of the photodetector 15dC includes the partial region 10RdC, the partial region 10RdA, the partial region 10RdB, and It is adjusted by an adjusting member to be described later so as not to include the partial region 10RdD. The photodetector 15dD is provided corresponding to the partial region 10RdD in the detection plane region 10R, and the photodetectable region 15dDR of the photodetector 15dD includes the partial region 10RdD, the partial region 10RdA, the partial region 10RdB, and It is adjusted by an adjusting member to be described later so as not to include the partial region 10RdC. In other words, the photodetectors 15dA to 15dD are configured such that the photodetectable region 15dAR includes the partial region 10RdA, the photodetectable region 15dBR includes the partial region 10RdB, and the photodetectable region 15dCR includes the partial region 10RdB. It is arranged so as to include the region 10RdC, so that the photodetectable region 15dDR includes the partial region 10RdD, and so that the photodetectable regions 15dAR, 15dBR, 15dCR, and 15dDR do not overlap each other. Each of the photodetectable regions 15dAR, 15dBR, 15dCR, and 15dDR extends in a direction intersecting with a direction in which the photodetectors 15dA to 15dD are arranged (that is, an X direction in the drawing) (that is, a Y direction in the drawing). It is adjusted by the adjusting member.

  Therefore, the reflected light Lr1 from the target object Ob1 arranged in the partial area 10RdA in the detection plane area 10R can be detected by the photodetector 15dA, and the object arranged in the partial area 10RdB in the detection plane area 10R. The reflected light Lr2 from the object Ob2 can be detected by the photodetector 15dB, and the reflected light Lr3 from the target object Ob3 arranged in the partial region 10RdC in the detection plane region 10R is detected by the photodetector 15dC. The reflected light Lr4 from the target object Ob4 arranged in the partial region 10RdD in the detection plane region 10R can be detected by the photodetector 15dD.

  Therefore, for example, when four target objects Ob1, Ob2, Ob3, and Ob4 are simultaneously arranged in each of the four partial regions 10RdA, 10RdB, 10RdC, and 10RdD in the detection plane region 10R, four photodetectors are provided. The planar positions of the four target objects Ob1, Ob2, Ob3, and Ob4 can be reliably detected by 15dA, 15dB, 15dC, and 15dD. In other words, for example, it is possible to reduce erroneous detection of the four target objects Ob1 to Ob4 that are simultaneously arranged in the detection plane region 10R as one object.

  That is, in this embodiment, in particular, the detection plane area 10R is divided into four partial areas 10RdA, 10RdB, 10RdC, and 10RdD, and a photodetector is provided for each partial area, so that the position detection light L2a in the detection plane area 10R. ˜L2d shares the detection of light reflected by the four target objects Ob1 to Ob4 for each partial region by the four photodetectors 15dA to 15dD. Accordingly, it is possible to reduce erroneous detection of the four target objects Ob1 to Ob4 arranged in the detection plane region 10R as one object.

  Here, the configuration of the photodetector will be described with reference to FIG. Although the configuration of the photodetector 15dA will be described here, the photodetectors 15dB, 15dC, and 15dD are configured in substantially the same manner as the photodetector 15dA.

  FIG. 9 is a schematic diagram showing a configuration of the photodetector according to the present embodiment.

  In FIG. 9, the photodetector 15 dA includes a light receiving element 151 such as a photodiode and an adjustment member 152. The adjusting member 152 is formed with a slit 152s. Light incident on the light receiving element 151 (for example, reflected light Lr1 from the target object Ob1) is limited by the slit 152s. In other words, the photodetectable region 15dAR of the photodetector 15dA is defined by the slit 152s. According to the adjustment member 152 in which such slits 152s are formed, the photodetectable region 15dA of the photodetector 15dA can be easily adjusted.

<Fifth Embodiment>
A fifth embodiment of the present invention will be described with reference to FIG. In FIG. 10, the same components as those in the first embodiment shown in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  FIG. 10 is a plan view schematically showing a position detection device according to the fifth embodiment.

  In FIG. 10, the position detection device according to the fifth embodiment includes the photodetectors 15eA, 15eB, 15eC, and 15eD in place of the photodetectors 15A and 15B, and the position detection according to the first embodiment described above. Unlike the apparatus, the other points are substantially the same as those of the position detection apparatus according to the first embodiment described above.

  The photodetectors 15eA to 15eD are arranged at the center of the detection plane region 10R. The photodetectors 15dA to 15dD are arranged on the outer surface of the above-described front mounting plate 30 (see FIG. 2). The photodetectors 15dA to 15dD may be disposed on the surface opposite to the outer surface of the cover plate 30 (that is, the surface of the cover plate 30 on the liquid crystal panel 20 side), or the light detectors 13 It may be arranged on the light reflecting surface 13t side.

  Like the photodetectors 15A and 15B in the first embodiment described above, the photodetectors 15eA to 15eD are configured to include a light receiving element such as a photodiode, for example, and can detect the intensity of the position detection lights L2a to L2d. It is comprised so that it may become. The photodetectable region 15dAR of the photodetector 15eA includes four partial regions 10ReA, 10ReB, 10ReC obtained by dividing the detection plane region 10R into four by two dividing lines intersecting each other at the center of the detection plane region 10R. And 10ReD are adjusted to include the partial region 10ReA, and the photodetectable region 15eBR of the photodetector 15eB is adjusted to include the partial region 10ReB of the four partial regions 10ReA, 10ReB, 10ReC, and 10ReD. The photodetectable region 15eCR of the photodetector 15eC is adjusted to include the partial region 10ReC among the four partial regions 10ReA, 10ReB, 10ReC, and 10ReC, and the photodetectable region 15eDR of the photodetector 15eD One partial area 10ReA, 10ReB, 10Re And it is adjusted to include a partial area 10ReD of 10ReD. Note that the above-described two dividing lines are virtual lines for convenience of explanation. In the present embodiment, one of the two dividing lines extends along the X direction, and the other. The dividing line extends along the Y direction. The two dividing lines intersect each other at the center of the detection plane region 10R. Photodetectors 15eA to 15eD are arranged in the vicinity of the position where the two dividing lines intersect.

  In other words, the photodetector 15eA is provided corresponding to the partial region 10ReA in the detection plane region 10R, and the photodetectable region 15eAR of the photodetector 15eA includes the partial region 10ReA and the partial region 10ReB, For example, adjustment is performed by an adjustment member such as a lens or a slit so as not to include the region 10ReC and the partial region 10ReD. The photodetector 15eB is provided corresponding to the partial region 10ReB in the detection plane region 10R, and the photodetectable region 15eBR of the photodetector 15eB includes the partial region 10ReB, the partial region 10ReA, the partial region 10ReC, and For example, it is adjusted by an adjustment member such as a lens or a slit so as not to include the partial region 10ReD. The photodetector 15eC is provided corresponding to the partial region 10ReC in the detection plane region 10R, and the photodetectable region 15eCR of the photodetector 15eC includes the partial region 10ReC and includes the partial region 10ReA, the partial region 10ReB, and For example, it is adjusted by an adjustment member such as a lens or a slit so as not to include the partial region 10ReD. The photodetector 15eD is provided corresponding to the partial region 10ReD in the detection plane region 10R, and the photodetectable region 1edDR of the photodetector 15eD includes the partial region 10ReD and includes the partial region 10ReA, the partial region 10ReB, and For example, it is adjusted by an adjusting member such as a lens or a slit so as not to include the partial region 10ReC. In other words, the photodetectors 15eA to 15eD are configured such that the photodetectable region 15eAR includes the partial region 10ReA, the photodetectable region 15eBR includes the partial region 10ReB, and the photodetectable region 15eCR is a partial region. It is arranged so as to include the region 10ReC, so that the photodetectable region 15eDR includes the partial region 10ReD, and so that the photodetectable regions 15eAR, 15eBR, 15eCR, and 15eDR do not overlap each other.

  Therefore, the reflected light Lr1 from the target object Ob1 arranged in the partial area 10ReA in the detection plane area 10R can be detected by the photodetector 15eA, and the object arranged in the partial area 10ReB in the detection plane area 10R. The reflected light Lr2 from the object Ob2 can be detected by the photodetector 15eB, and the reflected light Lr3 from the target object Ob3 arranged in the partial region 10ReC in the detection plane region 10R is detected by the photodetector 15eC. The reflected light Lr4 from the target object Ob4 arranged in the partial region 10ReD in the detection plane region 10R can be detected by the photodetector 15eD.

  Therefore, for example, when four target objects Ob1, Ob2, Ob3, and Ob4 are simultaneously arranged one by one in each of the four partial regions 10ReA, 10ReB, 10ReC, and 10ReD in the detection plane region 10R, four photodetectors are provided. The planar positions of the four target objects Ob1, Ob2, Ob3, and Ob4 can be reliably detected by 15eA, 15eB, 15eC, and 15eD. In other words, for example, it is possible to reduce erroneous detection of the four target objects Ob1 to Ob4 that are simultaneously arranged in the detection plane region 10R as one object.

<Sixth Embodiment>
A sixth embodiment of the present invention will be described with reference to FIG. In FIG. 11, the same reference numerals are given to the same components as the components according to the first embodiment shown in FIGS. 1 to 3, and description thereof will be omitted as appropriate.

  FIG. 11 is a cross-sectional view schematically showing the arrangement of photodetectors in the position detection apparatus according to the sixth embodiment.

  In the above-described first to fifth embodiments, the case where the detection region is a planar region has been described as an example. However, the position detection device according to the present invention is also applied to the case where the detection region is a spatial region. Can do.

  As shown in FIG. 11, the detection space area 10S as an example of the “detection area” according to the present invention defined on the outer surface side of the cover plate 30 is divided into two partial areas 10SA and 10SB. Photodetectors 15fA and 15fB included as photodetectable regions may be provided.

  Similarly to the photodetectors 15A and 15B in the first embodiment described above, the photodetectors 15fA and 15fB are configured to include light receiving elements such as photodiodes, and can detect the intensity of the position detection lights L2a to L2d. It is comprised so that it may become. The photodetectable area 15fAR of the photodetector 15fA is a partial area 10SA out of two partial areas 10SA and 10SB obtained by dividing the detection space area 10S into two along a plane along the outer surface of the cover plate 30, for example. The photodetectable region 15fBR of the photodetector 15fB is adjusted to include the partial region 10SB of the two partial regions 10SA and 10SB. In other words, the photodetector 15fA is provided corresponding to the partial region 10SA in the detection space region 10S, and the photodetectable region 15fAR of the photodetector 15fA includes the partial region 10SA and includes the partial region 10SB. For example, adjustment is performed by an adjustment member such as a lens or a slit. The photodetector 15fB is provided corresponding to the partial region 10SB in the detection space region 10S, and the photodetectable region 15fBR of the photodetector 15fB includes the partial region 10SB and does not include the partial region 10SA. For example, it is adjusted by an adjusting member such as a lens or a slit. In other words, the photodetectors 15fA and 15fB are such that the photodetectable region 15fAR includes the partial region 10SA, the photodetectable region 15fBR includes the partial region 10SB, and the photodetectable regions 15fAR and 15fBR do not overlap each other. So that it is arranged.

  Therefore, the reflected light Lr1 from the target object Ob1 arranged in the partial area 10SA in the detection space area 10S can be detected by the photodetector 15fA, and is arranged in the partial area 10RfB in the detection space area 10S. The reflected light Lr2 from the target object Ob2 can be detected by the photodetector 15fB.

  Therefore, for example, when two target objects Ob1 and Ob2 are simultaneously arranged in each of the two partial regions 10SA and 10SB in the detection space region 10S, the two target objects are detected by the two photodetectors 15fA and 15fB. The spatial positions of Ob1 and Ob2 can be reliably detected. In other words, for example, it is possible to reduce erroneous detection of two target objects Ob1 and Ob2 that are simultaneously arranged in the detection space region 10S as one object.

<Electronic equipment>
Next, specific examples of electronic devices to which the liquid crystal device according to the above-described embodiments can be applied will be described with reference to FIG.

  Here, an example in which the liquid crystal device including the position detection device according to the first embodiment described above is applied to a display unit of an in-vehicle car navigation system will be described. FIG. 12 is a perspective view showing the configuration of the car navigation system.

  As shown in FIG. 12, the car navigation system 1200 includes a main body 1210 and a display unit 1220 connected to the main body 1210. The main body 1210 is provided with an operation surface 1211 provided with operation buttons and the like, and an inlet 1212 for a recording medium such as a DVD. The display unit 1220 stores the liquid crystal device 100 according to the above-described embodiment, and an image formed in the display area 20R of the liquid crystal device 100, that is, a display of a navigation image, is displayed on the display screen 1220a of the display unit 1220. It is comprised so that it may be visually recognized. Further, by arranging a target object such as a finger or a touch pen on the display screen 1220a, the position detection lights L2a to L2d described above are reflected and detected by the photodetectors 15A and 15B. The position information of the target object Ob can be input.

  In addition to the electronic device described with reference to FIG. 12, a portable personal computer, a mobile phone, a television, a viewfinder type, a monitor direct view type video tape recorder, a pager, an electronic notebook, a calculator, a word processor, a work A station, a video phone, a POS terminal, etc. are mentioned. Needless to say, the present invention can be applied to these various electronic devices.

  In addition to the liquid crystal device described in the above embodiment, the present invention also includes a reflective liquid crystal device (LCOS) in which elements are formed on a silicon substrate, a plasma display (PDP), a field emission display (FED, SED), The present invention can also be applied to an organic EL display, a digital micromirror device (DMD), an electrophoresis apparatus, and the like.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed within a scope not departing from the gist or concept of the invention that can be read from the claims and the entire specification, and a position detection device with such a change. Electro-optical devices and electronic devices are also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Position detection unit, 10R ... Detection plane area | region, 10RA, 10RB ... Partial area | region, 12A, 12B, 12C, 12D ... Light source for position detection, 13 ... Light guide plate, 13a, 13b, 13c, 13d ... Side surface, 13va, 13vb , 13vc, 13vd ... light incident surface, 13s ... light emitting surface, 15A, 15B ... photodetector, 20 ... liquid crystal panel, 20R ... display region, 100 ... liquid crystal device

Claims (12)

A position detection device for detecting the position of a target object in a detection region,
A first position detection light source for emitting a first position detection light to the detection region;
A second position detection light source for emitting a second position detection light to the detection region;
The detection area is provided corresponding to each of a first area and a second area obtained by dividing the detection area into at least two parts, and the first and second position detection lights in the corresponding first area and second area are the target. A plurality of first photodetectors that respectively detect light reflected by the object;
A position detection device comprising:   2. The position detection device according to claim 1, wherein the plurality of first photodetectors are arranged such that respective photodetectable regions do not overlap each other in the detection region.   The position detection device according to claim 1, further comprising position information acquisition means for acquiring position information of the target object based on detection values detected by the plurality of first photodetectors.   4. The position detection device according to claim 1, wherein each of the plurality of first photodetectors includes an adjustment member that adjusts each of the photodetectable areas. 5.   Crosses the first light incident surface on which the first position detection light is incident, the second light incident surface on which the second position detection light is incident, and the first and second light incident surfaces The position detection apparatus according to claim 4, further comprising a light guide plate having a light emission surface that emits the incident first and second position detection lights to the detection region. The plurality of first photodetectors are arranged along a first side of the light guide plate,
6. The position according to claim 5, wherein a photodetectable region of each of the plurality of first photodetectors is adjusted by the adjustment member so as to extend in a direction intersecting the first side. Detection device.   The position detection device according to claim 5, wherein the plurality of first photodetectors are arranged on the light emitting surface side with respect to the light guide plate.   7. The position detection device according to claim 5, wherein the plurality of first photodetectors are disposed on the opposite side of the light emitting surface with respect to the light guide plate. 8. The detection area is provided corresponding to each of a third area and a fourth area obtained by dividing the detection area into at least two division ranges different from the first area and the second area. In the corresponding third area and fourth area, 9. The apparatus according to claim 1, further comprising: a plurality of second photodetectors that respectively detect the light reflected by the target object as the first and second position detection lights. Position detector.   The position detection device according to claim 9, wherein the plurality of first photodetectors and the plurality of second photodetectors are driven so as to detect light at different timings. The position detection device according to any one of claims 1 to 10,
An electro-optic panel having a display area at least partially overlapping the detection area;
An electro-optical device comprising:   An electronic apparatus comprising the electro-optical device according to claim 11.

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