JP4947080B2 - Position detecting device and electro-optical device - Google Patents

Description

The present invention relates to a position detection device and an electro-optical device, and more particularly to a configuration of a device that acquires position information of an object to be detected based on an optically detected value.

In general, in a display device including an electro-optical device such as a liquid crystal display, an illumination device such as a backlight may be used to make the display screen visible or to improve the visibility. . In addition, the display device may be provided with a designated position detecting means such as a touch panel on the display screen. In this case, the designated position is indicated by pointing a specific portion of the display screen with a pen or a finger. Detected and input to an information processing apparatus or the like.

As the pointing position detection means (position coordinate input means) such as the above touch panel, a capacitive touch panel or a resistive touch panel for mechanically and electrically detecting a contact state with the display screen is known. In addition, for example, when a large number of infrared rays run vertically and horizontally along the display screen and a corresponding photodetector is provided to detect these infrared rays, the finger or the like can be used when these infrared rays are blocked by a finger or the like. There is known an optical touch panel that can detect the position coordinates. Various types of optical touch panels are generally known. For example, there are those described in 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. Since the number increases, high manufacturing costs must be borne, and power consumption increases.

Accordingly, the present invention is to solve the above-described problems, and to provide a position detection device and an electro-optical device (display device) that can be configured so that the optical position detection means can be reduced in cost and power consumption. .

In view of such circumstances, the position detection device of the present invention is arranged in a planar matrix on a substrate, and a plurality of position detection light sources that emit position detection light in a direction intersecting the arrangement surface, A photodetector for detecting reflected light from the detection target of the position detection light emitted from the position detection light source, and toward the one side in the detection direction along the array surface of the plurality of position detection light sources; A first driving mode in which a first light emission distribution in which a light emission amount of a plurality of position detection light sources is gradually decreased and a light emission amount of the position detection light is inclined to the one side along the arrangement surface; A second light quantity in which the emitted light quantity of the plurality of position detection light sources is gradually decreased toward the other side opposite to the one side in the direction, and the emitted light quantity of the position detection light is inclined to the other side along the array surface. For switching between the second driving mode having the light emission distribution of A position for deriving position information along the detection direction of the detection object based on output components of the light detectors respectively resulting from the control means and the first light emission distribution and the second light emission distribution; And an information deriving unit.

According to the present invention, the light source control unit controls the plurality of position detection light sources, so that the light quantity distribution of the position detection light emitted in the direction intersecting the array surface is set on the array surface of the plurality of position detection light sources. A first light emission distribution and a second light emission distribution that are inclined to one side and the other side of the detection direction along the detection direction, respectively, and at least a part of the reflected light by the detection object at the time of forming both light emission distributions Each is detected by a photodetector, and a value corresponding to the detected light amount is output. Then, the output of the photodetector changes in accordance with the position of the detection target in the detection direction due to the inclination of the emitted light quantity along the detection direction existing in the both light emission distributions. Therefore, it becomes possible to obtain position information along the detection direction of the detection target based on the output components of the light detectors resulting from both light emission distributions. Particularly, the reflected light of the detection object based on both the first light emission distribution and the second light emission distribution is detected by the photodetector, and the arrangement direction of the detection objects is based on the output components respectively resulting from both. By obtaining the position information, it becomes difficult to be influenced by the level fluctuation of the external light, the emitted light quantity, and the reflected light quantity, so that the accuracy and reproducibility of the position information can be improved. Note that the planar matrix means that the arrangement of the position detection light sources spreads in a plane rather than a line, and is not intended to be limited to a grid-like arrangement mode such as a matrix.

In the present invention, as described above, a plurality of position detection light sources that emit position detection light are arranged in a plane, and these are driven by the light source control means to be opposite to each other in the detection direction along the arrangement surface. The first light emission distribution and the second light emission distribution which are inclined to each other are formed, and the reflected light from the detection object of both light emission distributions is detected by the photodetector. Since it is not necessary to prepare the number of devices corresponding to the resolution, the number of elements can be suppressed and the power consumption can be reduced. Therefore, the optical position detection device can be configured to be low in cost and low in power consumption.

Here, the method for deriving the position information of the detection object based on the output components of the photodetectors caused by both light emission distributions is not particularly limited, but the output components of the photodetectors caused by the both light emission distributions are not particularly limited. In addition to the method of directly acquiring position information using the ratio or difference, for example, the level of one light emission distribution is set so that the output components of the photodetectors caused by both light emission distributions match each other. The case where the position information of the detection target is derived based on the amount of increase / decrease of the level when it is increased / decreased is also included.

In one aspect of the present invention, the light source control means alternately forms the first light emission distribution and the second light emission distribution. Accordingly, the detection of the reflected light by the photodetector based on the first light emission distribution and the detection of the reflected light by the photodetector based on the second light emission distribution can be sequentially performed. It can be carried out close in time. In particular, the driving of the position detection light source for forming the first light emission distribution and the driving of the position detection light source for forming the second light emission distribution are reversed in phase based on a predetermined driving cycle. By doing so,
By analyzing the phase of the detection signal of the photodetector, it becomes possible to easily discriminate the output components respectively resulting from both light emission distributions.

In another aspect of the present invention, the light source control unit gradually decreases the amount of light emitted from the plurality of position detection light sources toward one side of the second detection direction that intersects the detection direction and extends along the arrangement surface. And a third driving mode in which a third light emission distribution in which the emitted light quantity of the position detection light is inclined to one side of the second detection direction along the arrangement surface, and the second detection direction The amount of emitted light of the plurality of position detection light sources is gradually decreased toward the other side opposite to the one side, and the amount of emitted light of the position detection light along the arrangement surface is the other side in the second detection direction. The position information deriving means switches between the third light emission distribution and the fourth light emission distribution, respectively. Crosses the array direction of the detection objects based on output components It derives the position information along the direction. In this case, since the position information along the second detection direction that intersects the detection direction can be obtained, the planar position information of the detection object can be acquired.

In this case, the light source control unit sequentially forms the first light emission distribution, the second light emission distribution, the third light emission distribution, and the fourth light emission distribution, and outputs each light emission. It is preferable to acquire the output component of the photodetector when the distribution is formed. According to this, since the positional information along the detection direction and the second detection direction is obtained sequentially, the planar position information of the detection target can be quickly acquired. In this case, the order of forming the four light emission distributions is not particularly limited.

The light source control means may be configured to use the first light output distribution or the third light by the plurality of first group light sources for position detection distributed among the plurality of position detection light sources on the arrangement surface. An output distribution is formed, among the plurality of position detection light sources, is distributed on the array surface, and the second group of position detection light sources is different from the first group of position detection light sources. Or the fourth light emission distribution may be formed. The light source control unit may form the first light emission distribution and the second light emission distribution by using all of the plurality of position detection light sources, respectively. In the former case, since the first light emission distribution and the second light emission distribution are formed using different position detection light sources, the light source can be easily controlled. In the latter case, since both light emission distributions can be formed using all the position detection light sources, it is possible to more accurately realize the slope of both light emission distributions.

In another aspect of the invention, the photodetector is arranged on an array surface of the plurality of position detection light sources. Originally, the light detector only needs to be able to detect at least a part of the reflected light of the position detection light by the detection target, so that the arrangement is not particularly limited as long as it is, but for position detection Since the photodetectors are also arranged on the arrangement surface on which the light sources are arranged, the main components of the position detection device can be installed together on the base, so that the device can be made compact and easy to manufacture. it can.

Next, an electro-optical device according to the present invention is arranged in a planar matrix on a substrate and emits position detection light in a direction intersecting the arrangement surface, and the plurality of position detection light sources. A plurality of positions toward one side of a detection direction along the array surface of the plurality of position detection light sources, and a photodetector that detects reflected light from the detection target of the position detection light emitted from the light source; A first driving mode in which a light emission amount of the detection light source is gradually decreased and a light emission distribution of the position detection light is inclined to the one side along the arrangement surface; Second light emission in which the emitted light amount of the plurality of position detection light sources is gradually decreased toward the other side opposite to the one side, and the emitted light amount of the position detection light is inclined to the other side along the array surface. Light source control means for switching between the second driving modes forming the distribution; Position information deriving means for deriving position information of the detection object along the detection direction based on output components of the photodetector respectively caused by the first light emission distribution and the second light emission distribution; And an electro-optic panel arranged so that a display region overlaps the arrangement surface with respect to the arrangement surface.

In one aspect of the present invention, the display region is disposed on the light emission side of the position detection light with respect to the arrangement surface, and a plurality of illumination light is emitted on the base in parallel with the position detection light. The illumination light sources are arranged in a plane. According to this, since a so-called direct-type illumination structure is provided, and illumination light emitted from a plurality of illumination light sources arranged on the base is irradiated to the display area of the electro-optical panel, the electro-optical panel Can be added, and the electro-optical device can be downsized and the number of parts can be reduced as compared with the case where a separate illumination device (backlight or the like) is used.

In another aspect of the invention, the electro-optical panel is disposed on a light emission side of the position detection light with respect to the arrangement surface, and the position detection light is transmitted through the electro-optical panel and opposite to the arrangement surface. The photodetector is arranged inside the electro-optical panel. According to this, since the position detection light is transmitted through the electro-optical panel and emitted to the opposite side, the reflected light from the detection object on the opposite side of the arrangement surface with respect to the electro-optical panel is arranged in the electro-optical panel. It becomes possible to detect with the light detector. Here, a single photodetector may be provided in the electro-optical panel, or a plurality of photodetectors may be provided. in this case,
The photodetector is preferably formed on the inner surface of the substrate constituting the electro-optical panel. The photodetector may be arranged on an array surface of the plurality of position detection light sources. In this case, since the photodetector is disposed on the same substrate together with the position detection light source and, in some cases, the illumination light source, the structure of the apparatus can be easily configured, and the apparatus can be made compact.

According to the present invention, it is possible to achieve an excellent effect that it is possible to realize a position detection device and an electro-optical device (display device) in which the optical position detection unit can be configured at low cost and low power consumption.

FIG. 3 is a schematic cross-sectional view schematically illustrating a schematic configuration of the position detection device and the electro-optical device according to the first embodiment. The schematic plan view which shows arrangement | positioning of the light source for position detection on the base | substrate of 1st Embodiment, and the light source for illumination. Explanatory drawing which shows the 1st light emission distribution and 2nd light emission distribution of 1st Embodiment. The schematic perspective view (a) which shows typically the light emission aspect of the position detection light source in the 1st light emission distribution of 1st Embodiment, and the light emission aspect of the position detection light source in the 2nd light emission distribution are shown typically. Schematic perspective view (b). Explanatory drawing which shows the 3rd light emission distribution and 4th light emission distribution of 1st Embodiment. The schematic perspective view (a) which shows typically the light emission aspect of the light source for position detection in the 3rd light emission distribution of 1st Embodiment, and the light emission aspect of the light source for position detection in a 4th light emission distribution are shown typically. Schematic perspective view (b). FIG. 6 is a schematic cross-sectional view illustrating a schematic configuration of a position detection device and an electro-optical device according to a second embodiment. FIG. 6 is a schematic plan view showing the arrangement of photodetectors in an electro-optical panel of a second embodiment. FIG. 10 is a schematic cross-sectional view illustrating a schematic configuration of a position detection device and an electro-optical device according to a third embodiment. The schematic plan view which shows arrangement | positioning of the photodetector on the base | substrate of 3rd Embodiment with the arrangement | positioning of the light source for position detection, and the light source for illumination. The timing chart which shows the light emission aspect of the light source for position detection of each embodiment, and the detection aspect of a photodetector. Graphs (a) and (b) showing light emission modes in two directions along an array of a plurality of position detection light sources in each embodiment. FIG. 2 is a schematic configuration block diagram illustrating a detection principle of position information according to the embodiment. The schematic structure block diagram which shows the drive structure of the several light source for position detection of embodiment. The schematic structure block diagram which shows another drive structure of the several light source for position detection of embodiment.

  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 an illumination device and an electro-optical device (position detection device) according to the first embodiment of the present invention, and FIG. 2 is a view of a light source and a light guide plate of the illumination device viewed from the back side. It is a rear view which shows a mode typically.

As shown in FIG. 1, the illuminating device 10 of this embodiment includes a plurality of illumination light sources 11 that emit illumination light L1, and position detection light sources 12 that emit position detection light L2a and L2b. Are arranged in a plane on the substrate 13. Further, a light diffusion plate 16 is disposed away from the illumination light source 11 and the position detection light source 12 on the emission side of the illumination light L1 and the position detection lights L2a and L2b. The base 13 is configured in a case shape that accommodates the illumination light source 11, the position detection light source 12, and the light diffusing plate 16, and the inner surface 13 a of the base 13 is formed as a reflective surface that reflects the illumination light L 1 such as white polyethylene or a mirror surface. Has been. The illumination light source 11 and the position detection light source 12 are arranged on the bottom 13 b of the base 13. Although not shown, for example, the illumination light source 11 and the position detection light source 12 are mounted on a wiring board. Further, a photodetector 15 is disposed outside the base 13 on the emission side of the position detection light, and the illumination device 10.
And forms a position detecting device.

On the light emitting side of the illuminating device 10, an electro-optical panel 20 made of a transmissive liquid crystal display body or the like.
Is placed. 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 plurality of pixels are arranged in a plane in the display area, and the display area is arranged so as to overlap with the arrangement surface 13 in a plane. 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 is driven by a drive signal output from a drive circuit 25 made of a semiconductor IC chip or the like, and is controlled so as to be in a predetermined transmission state for each pixel.

On the opposite side of the electro-optical panel 20 from the light guide plate 13, a light-transmitting surface plate 30 is disposed. On the outer surface of the surface plate 30 (the surface opposite to the electro-optical panel 20), the above-described photodetector. 15
Is placed. The light detector 15 is a light receiving element such as a photodiode, and is configured to detect the intensity of the position detection light. For example, as will be described later, when the position detection light is infrared, the photodetector 15 is also composed of a light receiving element having sensitivity to infrared. Note that at least one photodetector 15 may be provided, but a plurality of photodetectors 15 may be provided. Moreover, it is not limited to arrange | positioning on outermost surfaces, such as on the surface layer board 30 like the example of illustration, You may arrange | position in the inside of the electro-optical panel 20 and the inside of the base | substrate 13 so that it may mention later. In short, the photodetector only needs to be installed in a configuration that can detect at least part of reflected light of position detection light L2a and L2b from a detection object Ob described later.

The illumination light source 11 is composed of a light emitting element such as an LED (light emitting diode), for example, and emits, for example, white illumination light L1 in accordance with a drive signal output from a drive circuit (not shown). As shown in FIG. 2, the plurality of illumination light sources 11 are arranged on the base 13 so as to be planarly dispersed (that is, vertically and horizontally). The illumination light sources 11 are periodically arranged in an array surface 13P (indicated by a one-dot chain line in the figure) basically set along the bottom surface of the base 13. In the illustrated example, the illumination light source 11
Is composed of a light emitting element formed by integrating light emitting chips 11R, 11G, and 11B of three colors of red (R), green (G), and blue (B). For example, a blue light emitting diode and a fluorescent material There is no particular limitation as long as it emits light that can be used as illumination light, such as a white light-emitting diode formed by grouping.

The position detection light source 12 is composed of a light emitting element such as an LED (light emitting diode), for example, and position detection light L2a that is, for example, infrared light in accordance with a drive signal output from a drive circuit (not shown).
, L2b is released. The position detection light is not particularly limited, but is preferably one that can be detected separately from the illumination light L1 and external light by signal processing or the like to be described later, and preferably has a wavelength distribution or a light emission mode different from that of the illumination light L1. Moreover, it is preferable to have a wavelength range that is efficiently reflected by the detection object Ob of the present invention. For example, if the detection 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). As shown in FIG. 2, the position detection light sources 12 are arranged on the base 13 so as to be planarly dispersed (that is, vertically and horizontally). Similarly to the illumination light source 11, the position detection light source 12 is periodically arranged in an array surface 13 </ b> P (indicated by a one-dot chain line in the drawing) basically set along the surface of the bottom portion 13 b of the base 13. Yes. Here, in the present specification, a surface range that is limited to an array region in which a plurality of position detection light sources 12 are arrayed, and a surface along the array position of the position detection light sources 12 is referred to as the array surface 13P. . The array surface 13P is a plane in the illustrated example, but is not limited to a plane.

In the present embodiment, the array surface 13P has a rectangular shape in plan view. In the illustrated example, the illumination light sources 11 are arranged in a matrix along the vertical and horizontal sides of the arrangement surface 13P. That is, the illumination light sources 11 are arranged in a grid pattern in the X direction and the Y direction along the side. On the other hand, the position detection light source 12 has a plurality of columns and rows along the vertical and horizontal sides of the array surface 13P. The position detection light sources in the adjacent columns or rows are arranged obliquely, and a plurality of position detection light sources are arranged. The light sources 12 are arranged vertically and horizontally along an oblique direction with respect to the side of the arrangement surface 13P. That is, the position detection light sources 12 are arranged in the X direction and the Y direction along the side, respectively, but the arrangement mode is not a lattice shape along the X direction and the Y direction.
It is a grid in an oblique direction inclined with respect to the X direction and the Y direction. However, the illumination light source 1
1 and the position of the position detection light source 12 are not limited to the above-described configuration. For example,
The position detection light sources 12 may be arranged in a lattice form vertically and horizontally in the X direction and the Y direction along the side of the arrangement surface 13P.

In the illustrated example, the illumination light sources 11 and the position detection light sources 12 are alternately arranged.
When the number of the illumination light sources 11 and the number of the position detection light sources 12 are greatly different, a small number of light sources may be arranged for every plural number of light sources. Note that it is preferable that the arrangement form of the illumination light source 11 and the position detection light source 12 has a constant distribution density when viewed in any direction along the arrangement surface 13P. In the illustrated example, the arrangement range is set in the common arrangement plane 13P for both the illumination light source 11 and the position detection light source 12, but they may be arranged in different ranges.

In the illumination device 10 of the present embodiment, the illumination light L1 is emitted from the illumination light source 11 in a direction intersecting with the arrangement surface 13P (a direction orthogonal to the illustrated example), and the illumination light L1 passes through the light diffusion plate 16. It is made uniform and irradiated to the display area of the electro-optical panel 20. Since the display area of the electro-optical panel 20 is translucent, the illumination light L is selected according to the light transmittance of each pixel in the display area.
An image formed by modulating 1 can be viewed from the viewing side (upper side in the drawing) through the front panel 30.

On the other hand, the position detection lights L2a and L2b are emitted from the position detection light source 12 in a direction intersecting the array surface 13P (a direction orthogonal in the illustrated example), and the position detection lights L2a and L2b are emitted from the light diffusing plate 1.
6 and the display area of the electro-optical panel 20 are transmitted through the display board 30. Then, when the detection object Ob such as a finger is arranged on the surface of the cover plate 30, the position detection lights L2a and L2b are reflected by the detection object Ob, and at least a part of the reflected light is detected by the photodetector 15. Is detected.

In the present embodiment, the first light emission distribution D1 of the position detection light L2a emitted from the front panel 30 and the second light of the position detection light L2b emitted from the front panel 30 by the position detection light source 12. An outgoing distribution D2 is formed. The first light emission distribution D1 is controlled such that the amount of emitted light emitted from the plurality of position detection light sources 12 arranged as described above gradually decreases toward one Xa side in the X direction. The emitted light quantity of the position detection light L2a is a distribution that is inclined toward one Xa side in the X direction. The first light emission distribution D1 is indicated by a solid line in the graph of the light intensity distribution shown in FIG. 3, and is schematically shown in the schematic perspective view of FIG. At this time, the first light emission distribution D1 in the illustrated example has a flat light intensity distribution in the Y direction.
However, in the present invention, the light intensity distribution in the Y direction need not be flat in the first light emission distribution D1, and is not limited to the illustrated example.

On the other hand, in the second light emission distribution D2, the amount of emitted light emitted from the plurality of position detection light sources 12 arranged as described above is directed toward the other Xb side opposite to the one Xa side in the X direction. By being controlled so as to gradually decrease, the emitted light quantity of the position detection light L2b becomes the other Xb in the X direction.
The distribution is inclined to the side. The second light emission distribution D2 is indicated by a broken line in the graph of the light intensity distribution shown in FIG. 3, and is schematically shown in the schematic perspective view of FIG. At this time, the second light emission distribution D2 in the illustrated example has a flat light intensity distribution in the Y direction. However,
In the present invention, the light intensity distribution in the Y direction need not be flat in the second light emission distribution D2, and is not limited to the illustrated example. Here, in FIG. 3, a relative coordinate system in which the origin on the other Xb side is set to x = 0 and the maximum value on the Xa side is set to x = 1 is introduced as the position coordinate in the X direction.

As described above, since the first light emission distribution D1 configured by the position detection light L2a is a distribution inclined to one Xa side in the X direction, the detection object Ob moves to one Xa side in the X direction. The amount of reflected light of the position detection light L2a decreases, and the output component of the photodetector 15 corresponding to the amount of reflected light of the position detection light L2a also decreases according to the position of the detection object Ob in the X direction. On the other hand, since the second light emission distribution D2 constituted by the position detection light L2b is a distribution inclined to the other Xb side in the X direction, the position detection light when the detection object Ob moves to the one Xa side in the X direction. L2b
And the output component of the photodetector 15 corresponding to the reflected light amount of the position detection light L2b also increases according to the position of the detection object Ob.

Furthermore, in the present embodiment, the position detection light source 12 emits the third light emission distribution D1 of the position detection light L2a emitted from the front panel 30 and the position detection light L2b emitted from the front panel 30.
The fourth light emission distributions D2 are respectively formed. The third light emission distribution D3 is controlled such that the amount of emitted light emitted from the plurality of position detection light sources 12 arranged as described above gradually decreases toward one Ya side in the Y direction. The emitted light quantity of the position detection light L2a is a distribution that is inclined toward one Ya side in the Y direction. The third light emission distribution D3 is indicated by a solid line in the graph of the light intensity distribution shown in FIG. 5, and is schematically shown in the schematic perspective view of FIG. At this time, the third light emission distribution D3 in the illustrated example has a flat light intensity distribution in the X direction. However, in the present invention, the light intensity distribution in the X direction need not be flat in the third light emission distribution D3 and is not limited to the illustrated example. Here, in FIG. 5, as the position coordinates in the Y direction,
On the other hand, a relative coordinate system is introduced in which the origin on the Yb side is y = 0 and the maximum value on the Ya side is y = 1.

On the other hand, in the fourth light emission distribution D4, the amount of emitted light emitted from the plurality of position detection light sources 12 arranged as described above is directed toward the other Yb side opposite to the one Ya side in the Y direction. By being controlled so as to gradually decrease, the amount of emitted light of the position detection light L2b becomes Yb in the Y direction.
The distribution is inclined to the side. The fourth light emission distribution D4 is indicated by a broken line in the light intensity distribution graph shown in FIG. 5, and is schematically shown in the schematic perspective view of FIG. 6B. At this time, the fourth light emission distribution D4 in the illustrated example has a flat light intensity distribution in the X direction. However,
In the present invention, the light intensity distribution in the X direction need not be flat in the fourth light emission distribution D1, and is not limited to the illustrated example.

As described above, since the third light emission distribution D3 configured by the position detection light L2a is a distribution inclined to one Ya side in the Y direction, when the detection object Ob moves to one Ya side in the Y direction. The amount of reflected light of the position detection light L2a decreases, and the output component of the photodetector 15 corresponding to the amount of reflected light of the position detection light L2a also decreases according to the position of the detection object Ob in the Y direction. On the other hand, since the fourth light emission distribution D4 configured by the position detection light L2b is a distribution inclined to the other Yb side in the Y direction, the position detection light is detected when the detection object Ob moves to the one Ya side in the Y direction. L2b
And the output component of the photodetector 15 corresponding to the reflected light amount of the position detection light L2b also increases according to the position of the detection object Ob.

In the present embodiment, as described above, two symbols L2a and L2b are used as position detection light.
In the position information acquisition method to be described later, the position information in the X direction is acquired using the first light emission distribution D1 and the second light emission distribution D2, and the third light emission distribution is obtained. The position information in the Y direction is obtained using D3 and the fourth light emission distribution D4, but the position detection lights based on the two light emission distributions used for obtaining the position information in the respective directions are distinguished from each other. This is for convenience. Therefore, the position detection lights L2a and L2b may have different wavelength distributions that can be distinguished from each other, or may not have different wavelength distributions that cannot be distinguished from each other. Further, the light sources may be emitted from different groups of position detection light sources 12 or may be emitted from the same group of position detection light sources 12.

Next, a method for acquiring the position information of the detection object Ob based on the detection of the position detection lights L2a and L2b 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 L2a and L2b. 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.

Here, a first group of position detection light sources 12An (n = 1, 2,...) That emits position detection light L2a.
..., k; k is a natural number of 2 or more, and the first light emission distribution D1 is formed, and a second group of position detection light sources 12Bn (n = 1, 2,...) That emits position detection light L2b.・, K; k is 2
In the case where the second light emission distribution is formed by the above natural number), the case of obtaining the position coordinates in the X direction of the detection object Ob will be specifically described. The control amount (for example, current amount), the conversion coefficient and the emitted light amount of the first group of position detection light sources 12An are Ia, ka and Ea, the control amount (current amount) of the second group of position detection light sources 12Bn, the conversion coefficient, and the like. If the amount of emitted light is Ib, k, and Eb, the following equations (1) and (2) are established.

  Ea = k · Ia (1)

  Eb = k · Ib (2)

If the attenuation coefficient and the detected light amount of the first group position detection light L2a are fa and Ha, and the attenuation coefficient and the detected light amount of the second group position detection light L2b are fb and Hb, the following equation (3) and (
4) is established.

  Ha = fa · Ea = fa · k · Ia (3)

  Hb = fb · Eb = fb · k · Ib (4)

Therefore, Ha / Hb, which is the ratio of the detected light amounts of the two position detection lights, is the two light emission distributions D1, D2.
If it can be detected by the ratio of the output components of the photodetector 15 due to the above, Ha / Hb = (
fa · Ea) / (fb · Eb) = (fa / fb) · (Ia / Ib), so if the value corresponding to the ratio Ea / Eb of the amount of emitted light or the ratio Ia / Ib of the control amount is known, attenuation Coefficient ratio fa /
fb is determined by the following equation (5).

  fa / fb = (Ha / Hb). (Ib / Ia) (5)

Here, the attenuation coefficients fa and fb are the light amounts of the position detection lights L2a and L2b detected by the light detector 15 with respect to the light amounts (emission light amounts) of the position detection lights L2a and L2b emitted from the position detection light sources 12An and 12Bn. Since it is the ratio of (detected light quantity or output component), the detection object O
The first light emission distribution D1 and the second light emission distribution D2 shown in FIG. 3 depending on the position of b on the X coordinate.
It changes according to the inclination mode. Here, as the X coordinate, if a relative coordinate system is used in which the origin on the other Xb side in the X direction is x = 0 and the maximum value on the one Xa side is x = 1, the ratio of the attenuation coefficient is assumed. fa / fb is (1-x) / with respect to the coordinate x in the X direction of the detection object Ob.
It has a positive correlation with x. In any case, by setting the above correlation in advance, the value of the coordinate x, which is the position information of the detection object Ob, can be obtained based on the ratio fa / fb of the attenuation coefficient.

In order to obtain the attenuation coefficient ratio fa / fb, it is necessary to discriminate between the position detection lights L2a and L2b in order to obtain the detection light quantity ratio Ha / Hb. As such a method, for example, the first
The group position detection light source 12An and the second group position detection light source 12Bn may be provided separately, and the position detection lights L2a and L2b may be identified and detected. However, even if the position detection lights L2a and L2b cannot be identified and detected, the first group of position detection light sources 12An and the second group of position detection light sources 12Bn are turned on at different timings, and the detected light amounts are detected at the respective timings. By determining, the above discrimination becomes possible. For example, the first group of position detection light sources 12An and the second group of position detection light sources 12Bn blink in opposite phases (for example, a phase difference caused by a difference in propagation distance of a rectangular or sinusoidal drive signal can be ignored. There is a method of analyzing the waveform of the detected light quantity in a phase manner after operating so as to have a phase difference of 180 degrees with respect to each other in frequency. That is, by controlling the position detection light sources 12An and 12Bn, the first light emission distribution D1 and the second light emission distribution D2 are alternately formed, and the photodetector 15 output in accordance with the first light emission distribution D1 and the second light emission distribution D2. A certain process is performed based on the detected signal.

Even if the first group of position detection light sources 12An and the second group of position detection light sources 12Bn are not separately provided, the first light emission distribution D1 and the position detection light L2b by the position detection light L2a are provided.
The above-described discrimination can also be achieved by forming the second light emission distribution D2 by the same plurality of position detection light sources 12 at different timings and obtaining the detected light quantity at each timing.
For example, the first light emission distribution D1 and the second light emission distribution D2 are alternately formed by changing the distribution of the emitted light quantity of the same plurality of position detection light sources 12, and output according to this. A certain process is performed based on the detection signal of the photodetector 15.

FIG. 11 is a timing chart showing the control signal S1 of the position detection light source 12An, the control signal S2 of the position detection light source 12Bn, and the detection signal E0 of the photodetector 15. The control signals S1 and S2 are rectangular waves in the illustrated example, and are opposite in phase to each other, and the light emission timings of the position detection lights L2a and L2b are also opposite in phase. And the photodetector 15
The detection signal E0 is a response having an appropriate time delay td with respect to the control signals S1 and S2, and the detection component of the position detection light L2a (the output resulting from the first or third light emission distribution D1 or D3) Component) E1 and the sum of the detection component E2 of the position detection light L2b (the output component resulting from the second or fourth light emission distribution D2 or D4).

The detection signal E0 is analyzed in synchronization with the clock signals forming the control signals S1 and S2. In this case, out of the detection signal E0, the amplitude of the detection component E1 obtained at the phase corresponding to the phase of the control signal S1 and the amplitude of the detection component E2 obtained at the phase corresponding to the phase of the control signal S2 are derived. Thus, the ratio Ha / Hb of the detected light quantity can be obtained.
Then, the ratio fa / fb of the attenuation coefficient is calculated from the above equation (5), and the x coordinate of the detection object Ob can be obtained based on the ratio. The circuit configuration in this case is shown in FIG.

As shown in FIG. 13, the control unit S operating in accordance with the clock signal CLK outputs the control signals S1, S2 and the drive setting signals I1, I2 to the drive units IA, IB, and the drive units IA, IB
Based on these signals, the position detection light sources 12An and 12Bn are driven with the current values Ia and Ib. The photodetector 15 outputs a detection signal E0 by the detection circuit DS, and the detection signal E0 is analyzed by the analysis unit P. The analysis unit P analyzes the detection signal E0 based on the synchronization signal S0 output from the control unit S, and finally the ratio fa / Hb of the attenuation coefficient based on the derived ratio Ha / Hb and the current values Ia and Ib. Output signal Ps corresponding to fb or coordinate x is output.

However, the calculation of the x coordinate of the detection object Ob based on the above equation (5) after the analysis of the detection signal E0 is not limited to the above method. For example, one control amount Ia is fixed to a constant value Im, and the other control amount Ib is controlled so that a change in the detected waveform cannot be observed (that is, the detected light quantity ratio Ha / Hb becomes 1). The damping coefficient ratio fa / fb can be derived from the control amount Ib = Im · (fa / fb) at this time. In this case, the feedback signal Fs corresponding to the detected light quantity ratio Ha / Hb is fed back to the control unit S from the analysis unit P, and the drive setting signal I2 output from the control unit S in accordance with the value of the feedback signal Fs. By changing the current value I
b is controlled so that Ha / Hb = 1.

Alternatively, control may be performed so that Ha / Hb = 1 while always maintaining the sum of both control amounts at a constant value Im = Ia + Ib. In this case, according to the equation (5), Ib = Im · fb / (fa + fb
Therefore, 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 in the X direction of the detection object Ob as described above is as follows.
As described above, each of the detection components E using the first light emission distribution D1 and the second light emission distribution D2.
By obtaining 1 and E2, for example, the coordinate x can be obtained by driving the first group of position detection light sources 12An and the second group of position detection light sources 12Bn in opposite phases. on the other hand,
For the position information in the Y direction of the detection object Ob, the detection components E1 and E2 are obtained in the same manner as described above using the third light emission distribution D3 and the fourth light emission distribution D4 shown in FIG. The coordinate y shown in FIG. 5 can be acquired.

In the present embodiment, a plurality of position detection light sources 12 are arranged in a plane within the arrangement surface 13P. As an example, six rows of position detection light sources 12 in the X direction and position detection light sources in the Y direction are used. Consider a case in which 12 columns are arranged in a matrix of 6 columns. That is, the first rows 12A1 and 12A2 are six rows arranged in the X direction as the position detection light sources.
,..., 12A6 and second rows 12B1, 12B2, 12B3, 12B4, 12B5, 1
2B6, third row 12C1, 12C2, 12C3, 12C4, 12C5, 12C6, fourth row 12D1, 12D2, 12D3, 12D4, 12D5, 12D6, and fifth row 12E1
, 12E2, 12E3, 12E4, 12E5, 12E6 and the sixth row 12F1, 12F2,
This is a case where 12F3, 12F4, 12F5, and 12F6 are provided. In this case, an example of an aspect for forming each of the light emission distributions D1 to D4 is shown in FIGS. 12 (a) and 12 (b). FIG.
In a), the emitted light amounts Ea and Eb of 12A1 to 12A6 belonging to a plurality of position detection light source rows arranged in the X direction are respectively shown by the left and right solid lines, the two-dot chain line, and the central dotted line. In FIG. 12B, 12 belongs to a row of a plurality of position detection light sources arranged in the Y direction.
The emitted light amounts Ea and Eb of A1 to 12F1 are indicated by left and right solid lines, two-dot chain lines, and a central dotted line in each light source.

The first light emission distribution D1 is one X in the X direction as shown by a solid line in FIG.
It is formed by gradually reducing the amount of emitted light Ea on the a side. Similarly, the second light emission distribution D2 is formed by gradually reducing the amount of emitted light Eb toward the other Xb side in the X direction as indicated by a two-dot chain line in FIG. In these light emission distributions D1 and D2, each light source emits a constant amount of emitted light Ea, Eb in the Y direction as indicated by a solid line in FIG.
Is set to have.

On the other hand, the third light emission distribution D3 is formed by gradually reducing the amount of emitted light Ea toward one Ya side in the Y direction as indicated by a two-dot chain line in FIG. Further, the fourth light emission distribution D4 has a light emission amount Eb on the other Yb side in the Y direction as indicated by a dotted line in FIG.
It is formed by gradually reducing. In these cases, as indicated by the dotted lines in FIG. 12A, each light source is set to have a constant emission light amount Ea, Eb in the X direction.

As a configuration for forming each of the light emission distributions D1 to D4, the first group of position detection light sources 12An and the second group of plurality of position detection light sources 12Bn shown in FIG. These are controlled by the control unit S. That is, as shown in FIG. 14, current values Ia1, Ia2, Ia3, which are control amounts of the position detection light source 12An (n = 1 to k),
.., Iak is controlled by applying drive setting signals Ia1, Ia2, Ia3,..., Iak from the control unit S to the drive units IA1, IA2, IA3,. Current values Ib1 and Ib2 that are control amounts of the detection light source 12Bn (n = 1 to k), respectively.
, Ib3,..., Ibk are controlled by giving drive setting signals Ib1, Ib2, Ib3,..., Ibk from the control unit S to the drive units IB1, IB2, IB3,. The first light emission distribution D1 is formed by a plurality of position detection light sources 12An in the first group, and the second light emission distribution D2 is formed by a plurality of position detection light sources 12Bn in the second group. x is obtained, and the third light emission distribution D3 is formed by the plurality of position detection light sources 12An in the first group, and the fourth light emission distribution D2 is formed by the plurality of position detection light sources 12Bn in the second group. To obtain the coordinate y.

Further, the drive unit IA and the position detection light source 12An and the drive unit IB and the position detection light source 12Bn of the circuit shown in FIG. 13 are replaced with the drive units IA1 to IAk and the position detection light source 12 shown in FIG.
A1 to 12Ak, driving units IB1 to 1Bk, and position detection light sources 12B1 to 12Bk, and the driving units IA1 to IAk and IB1 to 1Bk are controlled by the control signal Sa1.
By driving the position detection light sources 12A1 to 12Ak and the position detection light sources 12B1 to 12Bk in opposite phases by Sak and Sb1 to Sbk, the positions in the X direction and the Y direction of the present embodiment by the circuit shown in FIG. All information derivation can be performed.

In this case, when the position information in the X or Y direction is derived using each of the light emission distributions D1 and D2 or D3 and D4, the method of controlling Ib so that Ha / Hb = 1 is as follows:
This corresponds to performing control to shift the light intensity of the gradient distribution of the second light emission distribution D2 or D4 up and down as a whole. That is, the light intensity of the second light emission distribution D2 or the fourth light emission distribution D4 indicated by the broken line in FIG. 3 or FIG.
The intersection position of the light emission distribution D1 and the second light emission distribution D2 (corresponding to a position where Ha / Hb = 1 is established) can be moved in the X direction or the Y direction. Therefore, Ha / Hb =
By changing the shift amount δ so that 1 is established, the intersection position becomes the detection object Ob.
It can be controlled to coincide with the position in the X direction or Y direction. Then, the coordinates x or y of the detection object Ob can be derived based on the shift amount δ at this time.

FIG. 15 is a configuration diagram illustrating a mode in which the control unit S controls the plurality of position-detecting light sources 12 in a matrix of 6 rows and 6 columns as described with reference to FIG. In this case, the plurality of position detection light sources 12 may be controlled separately in the first group and the second group as described above, but the light emission distributions D1 to D4 are formed using all these light sources. May be. Although the light emission distributions D1 to D4 are formed by all the position detection light sources 12 in this way, the brightness of each position detection light source needs to be switched within the drive cycle, but the control becomes more complicated. Since the light emission distribution is formed using a large number of light sources, it is possible to improve the uniformity of the slope of each light emission distribution and to improve the accuracy of the position information.

As described above, in the present embodiment, the position information in the X direction and the position information in the Y direction of the detection object Ob are respectively used as the first light emission distribution D1, the second light emission distribution D2, and the third light emission distribution. And the fourth light emission distribution D4, and the formation of the first light emission distribution D1 and the second light emission distribution D2, the derivation of the coordinate x based thereon, and the third light emission distribution. And the formation of the fourth light emission distribution D4 and the derivation of the coordinate Y based on the formation are alternately performed to detect the detection object O.
The plane position of b can be obtained. Actually, the first light source using a plurality of position detection light sources 12 is used.
The fourth to fourth light emission distributions D1 to D4 are sequentially formed, and the coordinates x and y are derived from the output components of the photodetector corresponding to the formation of each distribution. Here, the order of forming each distribution is not particularly limited. Further, by periodically repeating the formation of the four distributions D1 to D4, it becomes easy to analyze the output component corresponding to the cycle.

According to this embodiment, the electro-optical panel 2 of a type that controls the light modulation state for each pixel in particular.
The position information of the detection object Ob on the display screen can be detected while displaying by illuminating 0. At this time, the position detection lights L2a and L2b are emitted in a direction intersecting (orthogonal in the illustrated example) with the array surface 13P, and the reflected light reflected by the detection object Ob is detected by the photodetector 1.
By detecting at 5, it is possible to obtain the planar position information of the detection object Ob, so that position detection is possible compared to the conventional method of arranging a large number of light sources, photodetectors, optical switches, etc. on the display screen. Therefore, the number of elements can be greatly reduced, and the structure can be greatly simplified, the manufacturing cost can be reduced, and the power consumption can be reduced.

In particular, in the present embodiment, by using a plurality of arranged position detection light sources 12, an inclined light emission distribution can be strictly formed, so that the accuracy of position information can be increased. In addition, since the position detection light sources 12 are arranged in a plane, an appropriate light emission distribution inclined in both the X direction and the Y direction can be formed, thereby suppressing an increase in the number of elements. However, there is an advantage that the accuracy of the position information can be improved.

In the present embodiment, the first light emission distribution D1 and the second light emission distribution D2 or the third light emission distribution D3 and the fourth light emission distribution D4 having inclinations opposite to each other are used. Thus, the position information in the X direction and the Y direction is obtained, respectively, so that fluctuations in the absolute value level of the detected light amount of the light detector 15 due to external light, or the optical inside the position detection device and the electro-optical device, are detected. Each absolute value of the detected light amount (output component) due to the structure, for example, the shape of the inner surface 13a of the base 13, the light diffusing plate 16, the electro-optical panel 20, the surface mounting plate 30 and the like, due to fluctuations and variations in light transmittance. The influence of level fluctuations and variations can be eliminated. That is, when deriving the position information in the X direction, the ratio of the detected light quantity based on the first light emission distribution D1 and the second light emission distribution D2 (also the ratio of the detected light quantity of the position detection lights L2a and L2b). By using Ha / Hb, the influence of the absolute value levels of the emitted light amounts Ea and Eb, the emitted light amount, and the detected light amount of the position detection light is suppressed, and the third light is used when deriving the position information in the Y direction. By using the ratio of the detected light amount based on the emission distribution D3 and the fourth light emission distribution D4, the influence of the absolute value level is similarly suppressed.

Furthermore, in this embodiment, the emitted light amount E of the plurality of position detection light sources 12 arranged in a plane.
Since a and Eb are changed along the X direction and the Y direction to form the light emission distributions D1 to D4 having an inclination along the direction, and position information along the direction is obtained.
Since the inclination of the light emission distributions D1 to D4 used for deriving the position information is directly determined by the distribution of the emitted light quantity of the light source 12, it is hardly affected by variations in the light guide characteristics.

In the present embodiment, a plurality of illumination light sources 11 are arranged in a plane on the base 13 together with the plurality of position detection light sources 12, and the electro-optical panel 20 is illuminated by the plurality of illumination light sources 11. The illumination device 10 can be incorporated in the electro-optical device 100 in a compact manner.

In the present embodiment, the detected light amount Ha caused by the first light emission distribution D1 or the third light emission distribution D3 and the detected light amount caused by the second light emission distribution D2 or the fourth light emission distribution D4. Hb
The position information of the detection object Ob is derived based on the ratio of the detected light amounts Ha and Hb.
However, the present invention is not limited to the case where the position information is derived based on the ratio. For example, the coordinate x of the detection object Ob
, Y and the difference Ha−Hb between the detected light amounts, there is also a correlation, so that it is also possible to derive position information based on the difference between the detected light amounts Ha and Hb. In any case, for example, an arbitrary function of two output components, for example, F = (Ma · Ha) / (Mb · Hb) or F = Ma · Ha−
If position information is derived using both the detected light amounts Ha and Hb, which are output components resulting from both light emission distributions, such as using Mb · Hb (Ma and Mb are respectively coupling coefficients), the position information is derived. Can be performed more accurately and stably.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a schematic longitudinal sectional view of the present embodiment, and FIG. 8 is a plan perspective view showing a planar structure of the electro-optical panel 20 of the present embodiment. Since the second embodiment is configured in the same manner as in the first embodiment except for the arrangement of the photodetector 15 ', the same parts are denoted by the same reference numerals, and description thereof is omitted.

In the present embodiment, the photodetector 15 ′ is disposed inside the electro-optical panel 20. FIG.
As shown in FIG. 2, the electro-optical panel 20 includes pixels 20G each having a structure provided on the inner surfaces of the substrates 21 and 22 (surfaces facing the other substrate) arranged in a plane (vertically and horizontally). Each of the pixels 20G is configured such that the transmittance can be controlled independently by controlling the liquid crystal 24 with an electric field applied by an electrode formed therein. Between the pixels 20G, an inter-pixel region 2 shielded by a black matrix, a metal layer, or the like.
0H is provided, and the image quality is improved by projecting light other than the light passing through the pixel 20G.

In the present embodiment, the photodetector 15 ′ is configured so as not to affect the pixel 20G by being disposed in the inter-pixel region 20H, but detects reflected light received from the viewing side of the electro-optical panel 20. In order to be possible, it is formed on the viewing side with respect to the light shielding film for configuring the inter-pixel region 20H. For example, when a light shielding film is formed on the inner surface of the substrate 22 on the viewing side,
The photodetector 15 ′ is formed below the light shielding film on the inner surface of the substrate 22. When a light-shielding film is formed on the inner surface of the substrate 21 opposite to the viewing side, the photodetector 15 '
It is formed in an arbitrary layer of 2 or in an upper layer than the light shielding film on the inner surface of the substrate 21.

In the present embodiment, the single photodetector 15 ′ can detect the reflected light from all positions in the detection plane range substantially corresponding to the display area, for example, at the center area of the display area shown in the figure. Is arranged. However, a plurality of photodetectors 15 ′ may be provided. In this case, it is preferable that a plurality of photodetectors 15 ′ are distributed in the display area, and a plurality of photodetectors 15 ′ are arranged in the display area. More preferably, the photodetectors 15 'are arranged periodically.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS. FIG.
FIG. 10 is a schematic longitudinal sectional view of the present embodiment, and FIG. 10 is a plan view showing a planar structure of the bottom of the base 13 of the present embodiment. In the third embodiment, except for the arrangement of the photodetector 15 ″, it is configured in the same manner as in the first embodiment and the second embodiment, so the same parts are denoted by the same reference numerals and the description thereof is omitted. To do.

In the present embodiment, the light detector 15 ″ is disposed on the base 13 together with the illumination light source 11 and the position detection light source 12. In the illustrated example, a plurality of light detectors 15 ″ are provided.
And the position detection light source 12 away from the place where the position detection light source 12 is disposed.
, L2b are distributed at positions where they are not directly incident.

In the present embodiment, the reflected lights of the position detection lights L2a and L2b reflected by the detection object Ob are transmitted through the electro-optical panel 20 and the light diffusion plate 16 in reverse, and return to the inside of the base body 13.
3 is detected in a distributed manner in the illustrated example, but only a single photodetector 15 '' may be provided. However, in this case, the photodetector 15 ″ is disposed at a position where reflected light incident from all positions in the position detection range can be detected, for example, in the central region of the array surface 13P as illustrated. It is preferable.

Note that the illumination 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 modifications can be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Illuminating device, 11 ... Light source for illumination, 12, 12An, 12Bn ... Light source for position detection, 13
DESCRIPTION OF SYMBOLS ... Base | substrate, 13a ... Inner surface, 13b ... Bottom part, 15, 15 ', 15 "... Photodetector, 16 ... Light diffusing plate, 20 ... Electro-optical panel, 30 ... Front plate, D1 ... 1st light emission distribution, D2 ... second light emission distribution, D3 ... third light emission distribution, D4 ... fourth light emission distribution, Ea, Eb ... amount of emitted light, f
a, fb: attenuation coefficient, Ha, Hb: detected light quantity (output component)

Claims (9)

A plurality of position detection light sources arranged in a planar matrix and emitting position detection light in a direction intersecting with the arrangement surface;
A photodetector for detecting reflected light from a detection object of the position detection light emitted from the plurality of position detection light sources;
The amount of emitted light of the plurality of position detection light sources is gradually decreased toward one side in the detection direction along the array surface of the plurality of position detection light sources, and the amount of emitted light of the position detection light is increased along the array surface. The first driving mode having a first light emission distribution inclined to the one side and the emitted light quantity of the plurality of position detection light sources are gradually decreased toward the other side opposite to the one side in the detection direction. A light source control means for switching between a second driving mode that forms a second light emission distribution in which the emitted light quantity of the position detection light is inclined to the other side along the arrangement surface;
Position information deriving means for deriving position information of the detection object along the detection direction based on output components of the photodetector respectively caused by the first light emission distribution and the second light emission distribution; ,
A position detection apparatus comprising: The position detection device according to claim 1, wherein the light source control unit alternately forms the first light emission distribution and the second light emission distribution. The light source control means gradually decreases the amount of emitted light of the plurality of position detection light sources toward one side of a second detection direction that intersects the detection direction and extends along the array surface, and moves along the array surface. A third driving mode in which a third light emission distribution in which the amount of emitted position detection light is inclined to one side in the second detection direction and the other side opposite to the one side in the second detection direction; A fourth light emission distribution in which the emitted light quantity of the plurality of position detection light sources is gradually decreased toward the second side, and the emitted light quantity of the position detection light is inclined to the other side in the second detection direction along the array surface. Switching to the fourth driving mode,
The position information deriving unit is arranged along a direction intersecting with the arrangement direction of the detection objects based on output components of the photodetector caused by the third light emission distribution and the fourth light emission distribution, respectively. The position detection apparatus according to claim 1, wherein position information is derived. The light source control unit sequentially forms the first light emission distribution, the second light emission distribution, the third light emission distribution, and the fourth light emission distribution, while forming each light emission distribution. The position detection device according to claim 3, wherein an output component of the photodetector is acquired. 5. The position detection device according to claim 1, wherein the photodetector is arranged on an array surface of the plurality of position detection light sources. 6. A plurality of position detection light sources arranged in a planar matrix and emitting position detection light in a direction intersecting with the arrangement surface;
A photodetector for detecting reflected light from a detection object of the position detection light emitted from the plurality of position detection light sources;
The amount of emitted light of the plurality of position detection light sources is gradually decreased toward one side in the detection direction along the array surface of the plurality of position detection light sources, and the amount of emitted light of the position detection light is increased along the array surface. The first driving mode having a first light emission distribution inclined to the one side and the emitted light quantity of the plurality of position detection light sources are gradually decreased toward the other side opposite to the one side in the detection direction. A light source control means for switching between a second driving mode that forms a second light emission distribution in which the emitted light quantity of the position detection light is inclined to the other side along the arrangement surface;
Position information deriving means for deriving position information of the detection object along the detection direction based on output components of the photodetector respectively caused by the first light emission distribution and the second light emission distribution; ,
An electro-optical panel arranged such that a display region overlaps the array surface;
An electro-optical device comprising: The display area is arranged on the light emission side of the position detection light with respect to the arrangement surface, and a plurality of illumination light sources that emit illumination light in parallel with the position detection light are arranged in a plane on the base. The electro-optical device according to claim 6. The electro-optical panel is disposed on the light emission side of the position detection light with respect to the arrangement surface, and the position detection light is configured to pass through the electro-optical panel and emit to the opposite side of the arrangement surface. The electro-optical device according to claim 6, wherein the photodetector is disposed inside the electro-optical panel. The electro-optical device according to claim 6, wherein the photodetector is disposed on an array surface of the plurality of position detection light sources.

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