JP2011034375A - Optical position detection apparatus with illumination function, and display device with position detection function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical position detection apparatus with an illumination function and a display device with a position detection function for optimizing emitted light quantity distributions of both position detection light and illumination light even if a light transmission plate is commonly used for the position detection light and the illumination light. <P>SOLUTION: In an optical position detection apparatus with an illumination function 10, a light guide plate 13 takes in position detection light L2a-L2d composed of infra-red light and illumination light L4 composed of white light to emit them toward a detection area 10R. Between the light guide plate 13 and the detection area 10R, an intensity distribution changing layer 50 which distributes, in an in-plane direction, a light transmission area 51 through which the illumination light L4 and the position detection light L2a-L2d are transmissive and also a wavelength selective light shielding area 52 by which the illumination light L4 transmits and at least a part of the position detection light L2a-L2d is blocked are provided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical position detection device with an illumination function and a display device with a position detection function including the optical position detection device with an illumination function.

  In recent years, electronic devices such as mobile phones, car navigation systems, personal computers, ticket vending machines, and bank terminals have used display devices with a position detection function in which a touch panel is disposed on the front surface of a liquid crystal panel. Then, information is input while referring to an image displayed on the liquid crystal panel. Such a touch panel is configured as a position detection device for detecting the position of the target object in the detection region.

  As a detection method in such a position detection device, a resistance film method, an ultrasonic method, a capacitance method, an optical method, and the like are known. The resistive film method is low in cost but has low transmittance as well as the electrostatic capacity method, and the ultrasonic method and the electrostatic capacity method have a high response speed, but the environment resistance is low. On the other hand, the optical system is characterized in that the environmental resistance, the transmittance, and the response speed can be increased (see Patent Documents 1 and 2).

JP 2004-295644 A JP 2004-303172 A

  However, the position detection devices described in Patent Documents 1 and 2 require a number of light sources, photodetectors, and the like corresponding to the resolution of position coordinates to be detected in the vicinity of the display screen. There is a point.

  Therefore, as schematically shown in FIG. 9, the inventor of the present application provides a position detection light source 12 so as to face the side end portion of the light guide plate 13, and infrared position detection light emitted from the light guide plate 13. An optical position detection device that detects light reflected by L2 hitting a finger or the like with a photodetector 15 is being studied. In such an optical position detection device, the position of a finger or the like can be detected based on the relationship between the intensity of the position detection light L2 emitted from the light guide plate 13 and the distance from the position detection light source 12. There is an advantage that only a small number of position detection light sources 12 and photodetectors 15 are required.

  When a display device with a position detection function is configured using such a position detection device, a transmissive liquid crystal panel is provided on the light emission side with respect to the light guide plate. Further, a backlight light guide plate that emits illumination light incident from the side end portion with a uniform luminance distribution is disposed so as to overlap the position detection light guide plate. For this reason, since the display device with a position detection function requires two light guide plates, there are problems that the cost of components increases and the thickness of the display device with a position detection function increases.

  On the other hand, it is conceivable to provide both the position detection light source 12 and the white light source for the backlight with respect to the common light guide plate. In such a configuration, the intensity distribution of the output light amount of the position detection light from the light guide plate is changed. There is a problem that it cannot be formed properly and the detection accuracy is lowered. That is, since the position detection light is infrared light while the illumination light is visible light, if the light guide plate is configured so that the luminance distribution of the illumination light is uniform, the wavelength of the position detection light and the illumination light The intensity distribution of the emitted light quantity of the position detection light from the light guide plate deteriorates due to the influence of the emission characteristics from the light guide plate due to the difference.

  Such a problem is not limited to the case of constituting a display device with a position detection function, but in an optical position detection device with an illumination function having both an illumination function and a position detection function, a light guide plate for position detection light and illumination light. This is a problem that occurs when sharing the.

  In view of the above problems, an object of the present invention is to optimize the emitted light amount distribution of both the position detection light and the illumination light even when the position detection light and the illumination light share a light guide plate. An object is to provide an optical position detection device with an illumination function and a display device with a position detection function including the optical position detection device with an illumination function.

  In order to solve the above-described problems, the present invention optically detects the position of a target object in a detection region and emits illumination light in the visible region toward the side where the detection region is located. An illumination type light source that emits illumination light, a position detection light source that emits infrared position detection light, illumination light emitted from the illumination light source, and the position detection device A side end portion for taking in the position detection light emitted from the light source, and emitting the position detection light taken from the side end portion to the detection region, and the illumination region is positioned in the detection region; A light guide plate that emits light to the light-receiving side, a light-transmitting region that is provided between the light guide plate and the detection region, and that transmits the illumination light and the position detection light, and transmits the illumination light and the position detection light. At least part of An intensity distribution changing layer that disperses the wavelength-selective light-shielding region to be cut in an in-plane direction, and changes an intensity distribution of an emitted light amount of the position detection light emitted from the light guide plate toward the detection region; A light detector having a light receiving portion arranged toward the detection region so as to receive the position detection light reflected by the object, and a detection result of the light detector and an intensity distribution of the emitted light quantity of the position detection light; And a signal processing unit for detecting the position of the target object based on the signal processing unit.

  In the present invention, the “transmission region through which the illumination light and the position detection light are transmitted” only needs to transmit both the illumination light and the position detection light at a level that does not cause a problem in practice. This also includes the case where the transmittance of the detection light is not the same. In addition, “a wavelength-selective light-blocking region in which illumination light is transmitted and at least a part of position detection light is blocked” means that the transmittance of position detection light is lower than that of “transmission region” and the position detection light. As long as the transmittance of light is lower than the transmittance of illumination light.

  In the present invention, the position detection light in the infrared region emitted from the position detection light source is taken into the light guide plate, and then the position detection light is emitted from the light exit surface of the light guide plate. When reflected by the target object arranged on the light exit side of the light guide plate, the reflected light is detected by the photodetector. Here, if the intensity of the position detection light in the detection region and the distance from the position detection light source have a predetermined correlation, the position of the target object is detected from the received light intensity obtained via the photodetector. can do. Therefore, since it is not necessary to arrange a large number of optical elements along the detection region, a position detection device with low cost and low power consumption can be configured. In order to add an illumination function to such a position detection device, it is necessary to emit illumination light in the visible region and position detection light in the infrared region with a predetermined light amount distribution. Here, when a common light guide plate is used for visible illumination light and infrared position detection light, when the configuration of the light guide plate is matched with visible illumination light, the emission characteristics of the light guide plate differ depending on the wavelength. Therefore, the light amount distribution of the position detection light in the infrared region is deteriorated. However, in the present invention, between the light guide plate and the detection region, a light-transmitting region through which the illumination light and the position detection light are transmitted, and wavelength selectivity through which the illumination light is transmitted and at least a part of the position detection light is blocked. An intensity distribution changing layer in which the light shielding regions are distributed in the in-plane direction is provided. For this reason, since the intensity distribution of the emitted light quantity of the position detection light emitted toward the detection area can be changed and adjusted by the intensity distribution change layer, the intensity of the emitted light quantity to the detection area is also detected for the position detection light. Distribution can be optimized. Therefore, according to the present invention, even when the position detection light and the illumination light share a light guide plate, it is possible to optimize the intensity distribution of the emitted light amounts of both the position detection light and the illumination light. Therefore, even when the number of light guide plates is one, it is possible to realize an optical position detection device with an illumination function with high position detection accuracy.

  In the present invention, the illumination light source is provided in a first side portion of the side end portion of the light guide plate, and in the intensity distribution changing layer, the first end portion is opposed to the first side portion in the side end portion. It is preferable that the formation density of the translucent region is lower on the two side portion side than on the first side portion side. When the illumination light source is provided on the first side portion of the light guide plate, the light emission efficiency of the light guide plate on the second side portion away from the illumination light source is made higher than the emission efficiency on the first side portion side. Realize a brightness distribution. As a result, in the position detection light in the infrared region, the emission efficiency from the second side portion side becomes too high. However, in the present invention, since the formation density of the translucent region in the intensity distribution changing layer is low on the second side and high on the first side, the emitted light amount of the position detection light emitted toward the detection region It is possible to optimize the intensity distribution.

  In the present invention, a dot-like reflective layer having a higher formation density on the second side portion side than the first side portion side is provided on the opposite side of the light guide plate from the illumination light emission side. It is possible to adopt the configuration as described.

  In the present invention, the wavelength-selective light-shielding region is a dielectric multilayer film having a film configuration in which the illumination light is transmitted and at least a part of the position detection light is blocked, or the illumination light is transmitted and the position detection is performed. A configuration composed of a metal oxide film having a composition that blocks at least part of light can be employed.

  The optical position detection device with an illumination function to which the present invention is applied is used for a display device with a position detection function, for example. In this case, an electro-optic panel that modulates the illumination light and generates an image in a region that overlaps the detection region in plan view is provided on the light emission plate emission side.

  In such a display device with a position detection function, the electro-optic panel may display a switch image selected by the approach of the target object in the detection region. In this case, the switch image is displayed in plan view. It is preferable that the translucent region is provided at an overlapping position. According to such a configuration, it is possible to reliably avoid the location where the switch image is displayed from being a shadow of the wavelength-selective light-shielding region, so that erroneous input can be prevented.

  The display device with a position detection function according to the present invention is used for electronic devices such as mobile phones, car navigation systems, personal computers, ticket vending machines, and bank terminals, in addition to various display devices.

It is explanatory drawing which shows typically the whole structure of the optical position detection apparatus with an illumination function to which this invention is applied. 1 is an exploded perspective view of an optical position detection device with an illumination function and a display device with a position detection function to which the present invention is applied. It is explanatory drawing which shows the cross-sectional structure of the optical position detection apparatus with an illumination function to which this invention is applied, and the display apparatus with a position detection function. It is explanatory drawing which shows the signal processing content in the optical position detection apparatus with an illumination function to which this invention is applied, and the display apparatus with a position detection function. It is explanatory drawing which shows the lighting pattern of the light source for position detection at the time of position detection in the optical position detection apparatus with an illumination function to which this invention is applied, and the display apparatus with a position detection function. (A), (b) is explanatory drawing of the light-guide plate used for the optical position detection apparatus with an illumination function and the display apparatus with a position detection function to which this invention is applied, and explanatory drawing of an intensity distribution change layer. It is explanatory drawing which shows the positional relationship of the switch image and the translucent area | region of an intensity distribution change layer in the display apparatus with a position detection function to which this invention is applied. It is explanatory drawing of the electronic device using the display apparatus with a position detection function which concerns on this invention. It is explanatory drawing which shows the basic composition of a position detection apparatus.

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

(Schematic configuration of optical position detector with illumination function)
FIG. 1 is an explanatory view schematically showing the overall configuration of an optical position detection apparatus with an illumination function to which the present invention is applied. FIGS. 1 (a), (b), and (c) are optical types with an illumination function. An explanatory view showing a cross-sectional configuration of the position detection device, an explanatory view showing a positional relationship between the light guide plate and the light source used in the optical position detection device with an illumination function, and an explanation showing an attenuation state of the position detection light in the light guide plate FIG.

  The optical position detection device 10 with an illumination function shown in FIGS. 1A and 1B optically detects the position of the target object Ob in the detection region 10R and toward the side where the detection region 10R is located. It is an apparatus for emitting illumination light L4 in the visible region (region having a wavelength of 380 nm to 780 nm).

  In this embodiment, the optical position detection device 10 with an illumination function includes an illumination light source 41 that emits visible light L4 such as white light, and an infrared region (in this embodiment, a wavelength region of 800 nm to 1000 nm). Position detection light sources 12A to 12D that emit position detection lights L2a to L2d, and a light guide plate 13 that is common to the illumination light source 41 and the position detection light sources 12A to 12D. The light guide plate 13 includes a side end 13m and a side end 13m that incorporate the illumination light L4 emitted from the illumination light source 41 and the position detection lights L2a to L2d emitted from the position detection light sources 12A to 12D. And the light emission surface 13s for emitting the position detection light sources 12A to 12D to the detection region 10R.

  In the optical position detection apparatus 10 with the illumination function configured as described above, the illumination light L4 needs to be emitted with a uniform luminance distribution and is required to have high luminance. Further, the position detection lights L2a to L2d need to be emitted with a predetermined intensity distribution toward the detection region 10R as shown in FIG. 1C, for example. Therefore, in the present embodiment, the light guide plate 13 is configured to emit the illumination light L4 with a uniform luminance distribution, and an intensity distribution changing layer 50 is provided between the light guide plate 13 and the detection region 10R. ing. The detailed configuration of the optical position detection device with illumination function 10 having such a configuration will be described below with reference to FIGS. 2 and 3 together with the configuration of the optical position detection device with illumination function, and the light guide plate 13 and the intensity distribution. The detailed configuration of the change layer 50 will be described later with reference to FIG.

(Configuration of display device 100 with position detection function)
2 and 3 are explanatory diagrams of the optical position detection device 10 with illumination function and the display device 100 with position detection function to which the present invention is applied, and FIGS. 2 and 3 respectively show the display device 100 with a position detection function. It is explanatory drawing which shows the exploded perspective view of, and a cross-sectional structure.

  The display device with a position detection function 100 shown in FIGS. 2 and 3 includes an optical position detection device with an illumination function 10 and a liquid crystal device 200, and the optical position detection device with an illumination function is provided by the liquid crystal device 200. Based on the displayed image, the planar position of the target object Ob is detected when the target object Ob such as a finger is brought close to the detection region 10R.

  Such an optical position detection apparatus 10 with an illumination function includes position detection light sources 12A to 12D that emit position detection light L2a to L2d and light incident portions 13a to 13d to which the position detection lights L2a to L2d are incident. The light guide plate 13 and the light detector 15 are provided on one surface (upper surface in the drawing) of the light guide plate 13 that emits the position detection lights L2a to L2d propagated through the light guide plate 13. ing. The position detection light sources 12A to 12D are disposed so as to face the light incident portions 13a to 13d, and are preferably disposed in close contact with the light incident portions 13a to 13d.

  Hereinafter, the directions orthogonal to each other will be described as the X direction, the Y direction, and the Z direction, and the emission directions of the position detection lights L2a to L2d from the light guide plate 13 will be described as the Z direction.

  The light guide plate 13 is made of a transparent resin plate such as polycarbonate or acrylic resin, and the light that is incident from the light incident portions 13a to 13d and propagates through the light guide plate 13 gradually progresses in the propagation direction. The light is deflected and emitted from the light exit surface 13s. A reflection plate 14 composed of a reflection sheet or the like is disposed behind the light guide plate 13, and the reflection plate 14 returns the position detection lights L <b> 2 a to L <b> 2 d emitted from the back surface 13 t of the light guide plate 13 to the inside of the light guide plate 13. To function.

  In this embodiment, the light guide plate 13 has a substantially quadrangular planar shape including four side portions 13i to 13l, and the four corner portions 13e to 13h of the quadrangle become light incident portions 13a to 13d, respectively. Yes. Here, the light incident portions 13a to 13d are constituted by end faces (light incident surfaces) formed by removing the corner portions 13e to 13h of the light guide plate 13, for example.

  The position detection light sources 12A to 12D are composed of light emitting elements such as LEDs (light emitting diodes), and position detection lights L2a to L2d made of infrared light according to a drive signal output from a drive circuit (not shown). Release. The types of the position detection lights L2a to L2d are not particularly limited, but are preferably those that can be detected separately from external light by signal processing described later. The position detection lights L2a to L2d preferably have a wavelength range that is efficiently reflected by the target object Ob such as a finger or a touch pen. Therefore, if the target object Ob is a human body such as a finger, it is desirable that the infrared ray has a high reflectance on the surface of the human body (particularly near infrared light close to the visible light region, for example, near 850 nm in wavelength), or near 950 nm.

  The position detection light sources 12A to 12D are essentially provided in plural, and are configured to emit position detection light from different positions. Of the four position detection light sources 12A to 12D, two position detection light sources are paired to form a first light source pair, and the other two position detection light sources are paired to form a second light source pair. is doing. Here, the central optical axes of the position detection light sources 12A to 12D (position detection lights L2a to L2d) intersect each other. Therefore, the position detection light L2a and the position detection light L2b are emitted in the light guide plate 13 while propagating in directions opposite to each other in the direction indicated by the arrow A, and in a direction intersecting the propagation direction (Z direction). The position detection light L2c and the position detection light L2d are emitted from the surface 13s while propagating in opposite directions in the direction intersecting the direction indicated by the arrow A (direction indicated by the arrow B). The light is emitted from the surface 13s.

  In the display device with a position detection function 100 according to the present embodiment, an optical sheet 16 for leveling the position detection lights L2a to L2d is arranged on the light emitting side of the light guide plate 13 as necessary. In this embodiment, as the optical sheet 16, the first prism sheet 161 facing the light exit surface 13s of the light guide plate 13 is opposed to the first prism sheet 161 on the side opposite to the side where the light guide plate 13 is located. A second prism sheet 162 and a light scattering plate 163 facing the second prism sheet 162 on the side opposite to the side where the light guide plate 13 is located are used. A rectangular frame-shaped light shielding sheet 17 is disposed around the optical sheet 16. The light shielding sheet 17 prevents the position detection lights L2a to L2d emitted from the position detection light sources 12A to 12D from leaking.

(Configuration of the liquid crystal device 200)
The liquid crystal device 200 includes an electro-optical panel 20 on the side opposite to the side where the light guide plate 13 is positioned with respect to the optical sheet 16. In this embodiment, the electro-optical panel 20 is a transmissive liquid crystal panel, and has a structure in which two translucent substrates 21 and 22 are bonded together with a sealing material 23 and a liquid crystal 24 is filled between the substrates. . In this embodiment, the electro-optical panel 20 is an active matrix type liquid crystal panel, and on one side of the two light-transmitting substrates 21 and 22, a light-transmitting pixel electrode, a data line, a scanning line, and a pixel switching element ( (Not shown) is formed, and a translucent common electrode (not shown) is formed on the other side. Note that the pixel electrode and the common electrode may be formed on the same substrate. In the electro-optical panel 20, when a scanning signal is output to each pixel via a scanning line and an image signal is output via a data line, the orientation of the liquid crystal 24 is controlled in each of the plurality of pixels. As a result, an image is formed in the image display area 20R.

  In the electro-optical panel 20, one translucent substrate 21 is provided with a substrate overhanging portion 21 t that projects from the outer shape of the other translucent substrate 22. An electronic component 25 constituting a drive circuit or the like is mounted on the surface of the substrate extension portion 21t. Further, a wiring member 26 such as a flexible wiring board (FPC) is connected to the board projecting portion 21t. Note that only the wiring member 26 may be mounted on the substrate overhanging portion 21t. In addition, a polarizing plate (not shown) is arrange | positioned at the outer surface side of the translucent board | substrates 21 and 22 as needed.

  Here, in order to detect the position of the target object Ob, it is necessary to emit the position detection lights L2a to L2d to the viewing side where the operation with the target object Ob is performed. It is arranged closer to the viewing side (operation side) than the sheet 16. Accordingly, in the electro-optical panel 20, the image display region 20R is configured to be able to transmit the position detection lights L2a to L2d.

  The liquid crystal device 200 requires an illumination device for illuminating the electro-optical panel 20, and in this embodiment, the position detection light guide plate 13 is also used as the light guide plate 13 for the illumination light L4. Therefore, in this embodiment, the illumination light source 41 is arranged at the side end of the light guide plate 13. 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 illumination light L4 in accordance with a drive signal output from a drive circuit (not shown). In this embodiment, a plurality of illumination light sources 41 are arranged along the side portion 13k among the four side portions 13i, 13j, 13k, and 13l constituting the side end portion 13m of the light guide plate 13.

  As shown in FIG. 3, the light guide plate 14 is provided with an inclined surface 13w on the light emitting side surface portion adjacent to the side portion 13k, and the thickness of the light guide plate 13 gradually increases toward the side portion 13k. Yes. With the light incident structure having such an inclined surface 13w, the height of the side portion 13k is made to correspond to the height of the light emitting surface of the illumination light source 41 while suppressing an increase in the thickness of the portion where the light emitting surface 13s is provided. is there. In such an illuminating device, the illumination light emitted from the illumination light source 41 enters the light guide plate 13 from the side portion 13k of the light guide plate 13, and then the inside of the light guide plate 13 faces the opposite side portion 13l. Propagate and exit from the light exit surface 13s.

(Configuration of detection region 10R)
As shown in FIGS. 2 and 3, the photodetector 15 is disposed on the viewing side (operation side) of the electro-optical panel 20, and the photodetector 15 points the light receiving unit 15 a toward the detection region 10 </ b> R. The photodetector 15 includes a light receiving element such as a photodiode, and is configured to be able to detect the intensities of the position detection lights L2a to L2d. In this embodiment, since infrared rays are used as the position detection lights L2a to L2d, the photodetector 15 having at least sensitivity to infrared rays is used.

  In the present embodiment, the image display region 20R of the electro-optical panel 20 is a planar range in which a display image is displayed on the electro-optical panel 20. In this embodiment, the image display area 20R has a rectangular shape with four sides, has a congruent shape with the detection area 10R, and its position completely coincides with the detection area 10R in a plane. However, at least a part of the detection area 10R and the image display area 20R need only overlap in a plane.

  In this embodiment, in addition to the photodetector 15, a compensation photodetector 15x is also used. The compensation photodetector 15x is for compensating for the influence of temperature or the like on the detection result obtained via the photodetector 15, and does not detect the position detection lights L2a to L2d.

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

  First, in the display device 100 with a position detection function of the present embodiment, the position detection lights L2a to L2d emitted from the position detection light sources 12A to 12D are incident on the inside of the light guide plate 13 from the light incident portions 13a to 13d, respectively. The light is gradually emitted from the light exit surface 13 s while propagating through the light guide plate 13. As a result, the position detection lights L2a to L2d are emitted in a planar shape from the light emission surface 13s.

  For example, the position detection light L2a is gradually emitted from the light exit surface 13s while propagating through the inside of the light guide plate 13 from the light incident part 13a toward the light incident part 13b. Similarly, the position detection lights L2c and L2d are gradually emitted from the light exit surface 13s while propagating through the light guide plate 13. Therefore, when the target object Ob such as a finger is arranged in the detection region 10R, the position detection lights L2a to L2d are reflected by the target object Ob, and a part of the reflected light is detected by the photodetector 15.

  Here, the light amount of the position detection light L2a emitted to the detection region 10R is linearly attenuated with the distance from the position detection light source 12A as shown by a solid line in FIG. 1C, and the detection region 10R. It is considered that the amount of the position detection light L2b emitted to the line linearly attenuates with the distance from the position detection light source 12B, as indicated by a dotted line in FIG.

Further, the control amount (current amount), conversion coefficient, and emission light amount of the position detection light source 12A are Ia, k, and Ea, and the control amount (current amount), conversion coefficient, and emission light amount of the position detection light source 12B. Is Ib, k, and Eb,
Ea = k · Ia
Eb = k · Ib
It becomes. Further, if the attenuation coefficient and detected light amount of the position detection light L2a are set to fa and Ga, and the attenuation coefficient and detected light amount of the position detection light L2b are set to fb and Gb,
Ga = fa · Ea = fa · k · Ia
Gb = fb · Eb = fb · k · Ib
It becomes.

Therefore, if the photodetector 15 can detect Ga / Gb, which is the ratio of the detected light amounts of both position detection lights,
Ga / Gb = (fa · Ea) / (fb · Eb) = (fa / fb) · (Ia / Ib)
Therefore, if the values corresponding to the emission quantity ratio Ea / Eb and the control quantity ratio Ia / Ib are known, the attenuation coefficient ratio fa / fb is known. If there is a linear relationship between the ratio of the attenuation coefficient and the ratio of the propagation distances of both position detection lights, the positional information of the target object Ob can be obtained by setting this linear relationship in advance.

  As a method for obtaining the attenuation coefficient ratio fa / fb, for example, the position detection light source 12A and the position detection light source 12B blink in opposite phases (for example, a rectangular wave or sine wave drive signal is caused by a difference in propagation distance). The waveform of the detected light quantity is analyzed after the phase difference of 180 degrees is operated at a frequency at which the phase difference can be ignored. More realistically, for example, one control amount Ia is fixed (Ia = Im), and the other control amount is set so that the detected waveform cannot be observed, that is, the detected light quantity ratio Ga / Gb becomes 1. lb is controlled, and the ratio fa / fb of the attenuation coefficient is derived from the control amount Ib = Im · (fa / fb) at this time.

Further, the sum of both control amounts is always constant, that is, the following formula Im = Ia + Ib
You may control to satisfy | fill. In this case, the following formula Ib = Im · fb / (fa + fb)
So,
fb / (fa + fb) = α
Then, the following formula fa / fb = (1-α) / α
Thus, the ratio of the attenuation coefficient is obtained.

  Therefore, the position information of the target object Ob in the direction of arrow A can be obtained by driving the position detection light source 12A and the position detection light source 12B in opposite phases. Further, the position information of the target object Ob in the arrow B direction can be acquired by driving the position detection light source 12C and the position detection light source 12D in opposite phases. Therefore, the position coordinate of the target object Ob on the XY plane can be acquired by sequentially performing the detection operation in the A direction and the B direction in the control system.

  As described above, when acquiring the planar position information in the detection area 10R of the target object Ob based on the light amount ratio of the position detection light detected by the photodetector 15, for example, a microprocessor unit (MPU) is used as a signal processing unit. Thus, it is possible to adopt a configuration in which processing is performed in accordance with execution of predetermined software (operation program). Further, as will be described later with reference to FIG. 3, a configuration in which processing is performed by a signal processing unit using hardware such as a logic circuit may be employed. Such a signal processing unit may be incorporated as a part of the display device 100 with a position detection function, or may be configured inside an electronic apparatus on which the display device 100 with a position detection function is mounted.

(Configuration example of signal processor)
FIG. 4 is an explanatory diagram showing signal processing contents in the optical position detection device with illumination function 10 and the display device with position detection function 100 to which the present invention is applied, and FIGS. 4 (a) and 4 (b) respectively. It is explanatory drawing of the signal processing part of the optical position detector 10 with an illumination function to which this invention is applied, and the display apparatus 100 with a position detection function, and explanatory drawing which shows the processing content in the light emission intensity compensation command part of a signal processing part. .

  As shown in FIG. 4A, in the optical position detection device with illumination function 10 and the display device with position detection function 100 of the present embodiment, the position detection light source drive circuit 110 is variable with respect to the position detection light source 12A. A drive pulse is applied via the resistor 111, and a drive pulse is applied to the position detection light source 12B via the inverting circuit 113 and the variable resistor 112. For this reason, the position detection light source drive circuit 110 applies drive pulses having opposite phases to the position detection light source 12A and the position detection light source 12B to modulate and emit the position detection lights L2a and L2b. The light detected by the position detection lights L2a and L2b from the target object Ob is received by the common photodetector 15. In the light intensity signal generation circuit 140, a resistor 15r of about 1 kΩ is electrically connected in series to the photodetector 15, and a bias voltage Vb is applied to both ends thereof.

In the light intensity signal generation circuit 140, the signal processing unit 150 is electrically connected to the connection point P1 between the photodetector 15 and the resistor 15r. The detection signal Vc output from the connection point P1 between the photodetector 15 and the resistor 15r is expressed by the following equation: Vc = V15 / (V15 + resistance value of the resistor 15r)
V15: Expressed by an equivalent resistance of the photodetector 15. Therefore, comparing the case where the ambient light is not incident on the photodetector 15 and the case where the ambient light is incident on the photodetector 15, the detection is performed when the ambient light is incident on the photodetector 15. The level and amplitude of the signal Vc are increased.

  The signal processing unit 150 generally includes a position detection signal extraction circuit 190, a position detection signal separation circuit 170, and a light emission intensity compensation command circuit 180.

  The position detection signal extraction circuit 190 includes a filter 192 composed of a capacitor of about 1 nF, and the filter 192 removes a DC component from the signal output from the connection point P1 between the photodetector 15 and the resistor 15r. Functions as a high-pass filter. For this reason, the position detection signals Vd of the position detection lights L2a and L2b from the photodetector 15 are extracted by the filter 192 from the detection signal Vc output from the connection point P1 between the photodetector 15 and the resistor 15r. That is, while the position detection lights L2a and L2b are modulated, the ambient light can be considered to have a constant intensity within a certain period, so that the low frequency component or the direct current component caused by the ambient light is filtered. 192 to remove.

  The position detection signal extraction circuit 190 has an adder circuit 193 provided with a feedback resistor 194 of about 220 kΩ at the subsequent stage of the filter 192. The position detection signal Vd extracted by the filter 192 is a bias voltage Vb. Is output to the position detection signal separation circuit 170 as a position detection signal Vs superimposed on a voltage V / 2 that is ½ of.

  The position detection signal separation circuit 170 is electrically connected to the input lines of the switch 171, the comparator 172, and the comparator 172 that perform a switching operation in synchronization with the drive pulse applied to the position detection light source 12 </ b> A. And a capacitor 173. For this reason, when the position detection signal Vs is input to the position detection signal separation circuit 170, the position detection signal Ls is sent from the position detection signal separation circuit 170 to the light emission intensity compensation command circuit 180 during the period when the position detection light L2a is lit. The effective value Vea of the position detection signal Vs and the effective value Veb of the position detection signal Vs during the period when the position detection light L2b is lit are alternately output.

  The light emission intensity compensation command circuit 180 compares the effective values Vea and Veb, performs the process shown in FIG. 4B, and calculates the effective value Vea of the position detection signal Vs during the period in which the position detection light L2a is lit. Then, the control signal Vf is output to the position detection light source driving circuit 110 so that the effective value Veb of the position detection signal Vs during the period when the position detection light L2b is lit is the same level. That is, the light emission intensity compensation command circuit 180 has an effective value Vea of the position detection signal Vs during the period when the position detection light L2a is lit, and an effective value of the position detection signal Vs when the position detection light L2b is lit. When the values Veb are compared and they are equal, the current driving conditions for the position detection light sources 12A and 12B are maintained. On the other hand, when the effective value Vea of the position detection signal Vs during the period when the position detection light L2a is lit is lower than the effective value Veb of the position detection signal Vs during the period when the position detection light L2b is lit. The emission intensity compensation command circuit 180 decreases the resistance value of the variable resistor 111 and increases the amount of light emitted from the position detection light source 12A. Further, when the effective value Veb of the position detection signal Vs during the period when the position detection light L2b is lit is lower than the effective value Vea of the position detection signal Vs during the period when the position detection light L2a is lit, the light emission intensity The compensation command circuit 180 decreases the resistance value of the variable resistor 112 and increases the amount of light emitted from the position detection light source 12B.

  In this manner, in the optical position detection device 10 with illumination function and the display device 100 with position detection function, the detection amounts for the position detection lights L2a and L2b by the photodetector 15 are detected by the light emission intensity compensation command circuit 180 of the signal processing unit 150. Are controlled so that the control amounts (current amounts) of the position detection light sources 12A and 12B are controlled. Therefore, the emission intensity compensation command circuit 180 includes the effective value Vea of the position detection signal Vs during the period when the position detection light L2a is lit and the position detection signal Vs during the period when the position detection light L2b is lit. Since there is information relating to the control amount in the position detection light sources 12A and 12B so that the effective value Veb is at the same level, the position determination unit 120 is provided by outputting such information to the position determination unit 120 as the position detection signal Vg. Can obtain the position coordinates of the target object Ob in the detection region 10R in the arrow A direction. Further, if the same principle is used, the position coordinates of the target object Ob in the detection region 10R in the arrow B direction can be obtained. Therefore, the position coordinates on the XY plane of the target object Ob can be acquired.

  In the present embodiment, in the position detection signal extraction circuit 190, the filter 192 removes a direct current component caused by ambient light from the detection signal Vc output from the connection point P1 between the photodetector 15 and the resistor 15r. To extract the position detection signal Vd. For this reason, even when the detection signal Vc output from the connection point P1 between the photodetector 15 and the resistor 15r includes a signal component due to the infrared component of the ambient light, the influence of the ambient light is canceled. be able to.

(Position detection method in this embodiment)
FIG. 5 is an explanatory diagram illustrating a lighting pattern of a position detection light source when performing position detection in the optical position detection apparatus with illumination function 10 and the display apparatus with position detection function 100 to which the present invention is applied. (B) and (b) are explanatory diagrams when the position detection in the long side direction and the position detection in the short side direction of the light guide plate 13 (detection region 10R) are performed, respectively.

  In the optical position detection apparatus 10 with an illumination function of this embodiment, when detecting the position of the light guide plate 13 (detection region 10R) in the long side direction, as shown in FIG. , 12D are driven in the same phase, the position detection light sources 12B, 12C are driven in the same phase, and the position detection light sources 12A, 12D and the position detection light sources 12B, 12C are driven in the opposite phase, so that the light guide plate 13 is driven. An intensity distribution of the position detection light is generated in the long side direction (X direction) of the (detection region 10R).

  Further, when detecting the position of the light guide plate 13 (detection region 10R) in the short side direction, as shown in FIG. 5B, the position detection light source 12A, 12C is driven in the same phase, the position detection light sources 12B and 12D are driven in the same phase, and the position detection light sources 12A and 12C and the position detection light sources 12B and 12D are driven in the opposite phase, so that the light guide plate 13 ( An intensity distribution of the position detection light is generated in the short side direction (Y direction) of the detection region 10R).

  Even with this method, the position coordinates of the target object Ob on the XY plane can be acquired. In addition, according to the configuration in which a plurality of such position detection light sources are turned on simultaneously, for example, the light / dark gradient distribution of the position detection light can be suitably obtained in a wider range than the configuration in which one position detection light source is turned on. More accurate position detection is possible.

  In this embodiment, when the position of the light guide plate 13 (detection region 10R) in the long side direction is detected, the position detection light sources 12A and 12D are turned on and the position detection light sources 12B and 12C are turned on. The position detection in the long side direction is performed based on the difference between the detection results of the photodetector 15 in the period of time. Further, when position detection in the short side direction of the light guide plate 13 (detection region 10R) is performed, a period in which the position detection light sources 12A and 12C are lit and a period in which the position detection light sources 12B and 12D are lit. The position in the short side direction is detected based on the difference between the detection results of the light detector 15 in FIG. Also by this method, the influence of such environmental light can be canceled. Further, if the intensity distribution shown in FIG. 1C is simply increased or simply decreased, position detection can be performed even when there is no linear relationship.

(Configuration of light guide plate 13 and intensity distribution changing layer 50)
FIGS. 6A and 6B are explanatory diagrams of the light guide plate 13 used in the optical position detection device with illumination function 10 and the display device with position detection function 100 to which the present invention is applied, and the intensity distribution changing layer 50. It is explanatory drawing.

  In the optical position detection device with illumination function 10 and the display device with position detection function 100 of the present embodiment, the side portions of the light guide plate 13 are arranged so that the luminance distribution of the illumination light emitted from the light guide plate 13 is uniform. It has a light guide structure in which the light amount ratio of the emitted light from the light emitting surface 13s to the propagated light monotonously increases from the 13k (first side part) side to the opposite side part 13l (second side part). is doing. For example, as shown in FIG. 6A, the light guide structure is configured by a white dot-like reflective layer 13 p formed on the back surface 13 t of the light guide plate 13. In addition, the light guide structure may be constituted by a fine uneven refractive surface for light deflection or light scattering formed on the light exit surface 13s or the back surface 13t of the light guide plate 13. When the dot-like reflection layer 13p is used, the dot-like reflection layer 13p is formed with a higher density in the second side portion 13l facing the side portion 13k than the side portion 13k of the light guide plate 13. For this reason, it is possible to make the luminance equal between the luminance of the side portion 13k near the illumination light source 41 in the light guide plate 13 and the side portion 13l side of the light guide plate 13 away from the illumination light source 41. .

  In this embodiment, the light guide plate 13 also has a function of taking the position detection lights L2a to L2d and emitting them from the light exit surface 13s. The illumination light L4 is white light (visible range light), whereas the position detection lights L2a to L2d are in the infrared range, and the illumination light L4 and the position detection lights L2a to L2d have different wavelengths. The emission efficiency from the light guide plate 13 is also different. For this reason, the emitted light amounts of the position detection lights L2a to L2d emitted from the light guide plate 13 deviate from the intensity distribution described with reference to FIG. More specifically, the position detection lights L2a to L2d have low emission efficiency at the side portion 13k of the light guide plate 13 and high emission efficiency at the side portion 13l of the light guide plate 13.

  Therefore, in this embodiment, as shown in FIGS. 1, 2, and 3, an intensity distribution changing layer 50 is provided between the light guide plate 13 and the detection region 10R. In this embodiment, the intensity distribution changing layer 50 is disposed between the light guide plate 13 and the optical sheet 16. However, the intensity distribution changing layer 50 may be disposed between the optical sheet 16 and the inspection region 10R.

  In any case, the intensity distribution changing layer 50 transmits visible light (illumination light L4) and infrared light (position detection light L2a to L2d) and a light transmission region 51 and visible light (illumination light L4). In addition, wavelength selective light shielding regions 52 in which at least a part of infrared light (position detection lights L2a to L2d) are blocked by reflection or absorption are distributed in the in-plane direction. Here, the light-transmitting region 51 only needs to transmit both the illumination light L4 and the position detection lights L2a to L2d at a level that does not cause a problem in practice, and the transmittance of the illumination light L4 and the position detection lights L2a to L2d. The term “transmittance” includes the case where the transmittance is not the same. The wavelength-selective light-shielding region 52 is such that the transmittance of the position detection lights L2a to L2d is lower than that of the “transmission region 51” and the transmittance of the position detection lights L2a to L2d is higher than the transmittance of the illumination light L4. Should be low.

  As shown in FIG. 6B, in this embodiment, the formation density of the light transmission region 51 in the intensity distribution changing layer 50 is high at the first side portion 13k (first side portion side), and the side portion 13l (second side). The formation density of the light-transmitting regions 51 continuously changes from the first side portion 13k to the side portion 13l. In forming this distribution, in this embodiment, the circular translucent region 51 is formed more in the first side portion 13k (first side portion side) and less in the side portion 13l (second side portion side). Accordingly, when the position detection lights L2a to L2d are emitted from the light guide plate 13, the amount of emitted light is small at the side portion 13k of the light guide plate 13 and the amount of emitted light is large at the side portion 13l of the light guide plate 13. Such an imbalance is alleviated by the intensity distribution changing layer 50. Therefore, in the detection region 10R, the emitted light amounts of the position detection lights L2a to L2d emitted from the light guide plate 13 have the intensity distribution described with reference to FIG. In the present embodiment, the formation density of the translucent regions 51 in both directions is equal to the side portions 13k and 13l of the light guide plate 13.

  The intensity distribution changing layer 50 can be composed of various inorganic materials or organic materials. For example, a dielectric multilayer film configured to transmit visible light and reflect infrared light by alternately laminating dielectric layers having different dielectric constants, such as silicon oxide film and titanium oxide film, is used. Can be configured. When such a dielectric multilayer film is used, a configuration in which a wavelength-selective light-shielding region 52 made of a dielectric multilayer film is formed only on a part of the light emitting surface 13 s of the light guide plate 13, or one surface of the optical sheet 16 is formed. A configuration in which the wavelength-selective light-shielding region 52 made of a dielectric multilayer film is formed only in part can be adopted. In this case, the region where the dielectric multilayer film is not formed becomes the light transmitting region 51. Further, a wavelength-selective light-shielding region 52 made of a dielectric multilayer film is formed only on a part of one surface of the translucent sheet to form a sheet-like intensity distribution changing layer 50, and the sheet-like intensity distribution is changed. The layer 50 may be placed on the light guide plate 13.

  The intensity distribution changing layer 50 may be a metal oxide film such as an ITO (Indium Tin Oxide) film. The ITO film has a transmittance of 80% or more in the visible region (wavelength range of 380 nm to 780 nm), but has a transmittance of 70% or less in the infrared region (wavelength range of 800 nm to 1000 nm). It has the property of transmitting and absorbing infrared light. Accordingly, in configuring the intensity distribution changing layer 50, a configuration in which the wavelength-selective light-shielding region 52 made of an ITO film is formed only on a part of the light exit surface 13s of the light guide plate 13 or one surface of the optical sheet 16 is provided. A configuration in which the wavelength-selective light-shielding region 52 made of an ITO film is formed only on the part can be adopted. In this case, a region where the ITO film is not formed becomes the light transmitting region 51. Further, a wavelength-selective light-shielding region 52 made of an ITO film is formed only on a part of one surface of the translucent sheet to form a sheet-like intensity distribution changing layer 50, and the sheet-like intensity distribution changing layer 50 is formed. May be overlaid on the light guide plate 13.

  In the form shown in FIG. 6B, the light-transmitting region 51 is circular. However, the shapes of the light-transmitting region 51 and the wavelength-selective light-shielding region 52 are not limited to circles, and may be rectangular. Good.

(Main effects of this form)
As described above, in the optical position detection device with illumination function 10 and the display device with position detection function 100 of the present embodiment, the position detection lights L2a to L2d are emitted from the light emission surface 13s of the light guide plate 13, and this is the light guide plate. When the light is reflected by the target object Ob arranged on the exit side of 13, the reflected light is detected by the photodetector 15. Here, if the intensity of the position detection lights L2a to L2d in the detection region 10R and the distance from the position detection light sources 12A to 12D have a predetermined correlation, the light reception obtained through the photodetector 15 is obtained. The position of the target object Ob can be detected from the intensity. Therefore, since it is not necessary to arrange a large number of optical elements along the detection region 10R, the optical position detection device 10 with an illumination function with low cost and low power consumption can be configured.

  Moreover, in the optical position detection apparatus 10 with the illumination function of the present embodiment, a light transmission region 51 through which the illumination light L4 and the position detection lights L2a to L2d are transmitted, and the illumination light, between the light guide plate 13 and the detection region 10R. There is provided an intensity distribution changing layer 50 in which wavelength selective light shielding regions 52 that transmit L4 and block at least a part of the position detection lights L2a to L2d are distributed in the in-plane direction. For this reason, the intensity distribution of the emitted light quantity of the position detection lights L2a to L2d emitted toward the detection area 10R can be adjusted by the intensity distribution changing layer 50. Therefore, the position detection lights 10R are also detected for the position detection lights L2a to L2d. It is possible to optimize the intensity distribution of the amount of light emitted to the.

  More specifically, when the illumination light source 41 is provided on the side portion 13k (first side portion) of the light guide plate 13, the side portion 13l (second side portion) of the light guide plate 13 away from the illumination light source 41. As a result of realizing a uniform luminance distribution by making the emission efficiency on the side higher than the emission efficiency on the side portion 13k side, the emission efficiency on the side portion 13l side becomes higher in the infrared position detection lights L2a to L2d. It will be too much. However, in this embodiment, since the formation density of the light transmission regions 51 in the intensity distribution changing layer 50 is low on the side portion 13l side and high on the side portion 13k, the position detection light L2a to be emitted toward the detection region 10R. The intensity distribution of the emitted light quantity of L2d can be adjusted and optimized.

  Therefore, according to the present embodiment, even when the position detection light and the illumination light share a light guide plate, it is possible to optimize the intensity distribution of the emitted light amounts of both the position detection lights L2a to L2d and the illumination light L4. it can. Therefore, even when the number of light guide plates 13 is one, the optical position detection device 10 with an illumination function with high position detection accuracy can be realized.

(Example of the formation position of the translucent region 51 of the intensity distribution changing layer 50)
FIG. 7 is an explanatory diagram showing the positional relationship between the switch image and the translucent region 51 of the intensity distribution changing layer 50 in the display device with a position detection function 100 to which the present invention is applied, and FIGS. These are explanatory drawing which shows the position of a switch image, and explanatory drawing which shows the position of the translucent area | region 51. FIG.

  In the display device with a position detection function 100 described with reference to FIG. 2, when a plurality of switch images 61 are displayed on the menu screen shown in FIG. 7A by the electro-optical panel 20, a finger (target object Ob) is displayed on the switch screen. The position of the position in the detection region 10 </ b> R when the position is close is specified by the optical position detection device 10 with an illumination function of this embodiment. In such a case, it is preferable to provide the transparent region 51 of the intensity distribution changing layer 50 described with reference to FIG. 6 at a position overlapping the switch image 61 in plan view. According to such a configuration, it is possible to reliably avoid the location where the switch image 61 is displayed from being shaded by the wavelength-selective light-shielding region 52, thereby preventing erroneous input. In the form shown in FIG. 7B, the formation density of the light transmission regions 51 in the intensity distribution changing layer 50 is high at the first side portion 13k (first side portion side), and the side portion 13l (second side portion side). ), The size of the light-transmitting region 51 is large at the first side portion 13k (first side portion side) and small at the side portion 13l (second side portion side).

(Example of mounting on electronic equipment)
An electronic apparatus to which the display device with a position detection function 100 described with reference to FIGS. 1 to 7 is applied will be described with reference to FIG. FIG. 8 is an explanatory diagram of an electronic apparatus using the display device with a position detection function according to the present invention. FIG. 8A shows a configuration of a mobile personal computer including the display device 100 with a position detection function. The personal computer 2000 includes a display device 100 with a position detection function as a display unit and a main body 2010. The main body 2010 is provided with a power switch 2001 and a keyboard 2002. FIG. 8B shows a configuration of a mobile phone provided with the display device 100 with a position detection function. The cellular phone 3000 includes a plurality of operation buttons 3001, scroll buttons 3002, and the display device 100 with a position detection function as a display unit. By operating the scroll button 3002, the screen displayed on the display device with a position detection function 100 is scrolled. FIG. 8C shows a configuration of a personal digital assistant (PDA) to which the display device 100 with a position detection function is applied. The information portable terminal 4000 includes a plurality of operation buttons 4001, a power switch 4002, and the display device 100 with a position detection function as a display unit. When the power switch 4002 is operated, various types of information such as an address book and a schedule book are displayed on the display device 100 with a position detection function.

  In addition, as an electronic device to which the display device 100 with a position detection function is applied, a digital still camera, a liquid crystal television, a viewfinder type, a monitor direct-view type video tape recorder, a car navigation device, a pager, Examples include electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, bank terminals, and other electronic devices. And the display apparatus 100 with a position detection function mentioned above is applicable as a display part of these various electronic devices.

10..Optical position detector with illumination function, 10R..Detection area, 12A, 12B, 12C, 12D..Light source for position detection, 13..Light guide plate, 13a, 13b, 13c, 13d..Light incident part , 13e, 13f, 13g, 13h .. corner portion, 13i, 13j, 13k, 13l .. side portion, 13p .. dot-like reflective layer, 13s .. light exit surface, 15 .. photodetector 15a. Light receiving part, 20 ... Electro-optical panel, 50 ... Intensity distribution change layer, 51 ... Translucent area, 52 ... Wavelength selective light shielding area, 61 ... Switch image, 100 ... Display device with position detection function, 200 .. Liquid crystal device, L2a, L2b, L2c, L2d .. Position detection light, L4 .. Illumination light

Claims (6)

An optical position detection device with an illumination function that optically detects a position of a target object in a detection region and emits illumination light in a visible region toward a side where the detection region is located,
An illumination light source that emits the illumination light;
A position detection light source for emitting infrared position detection light;
A side end portion for taking in the illumination light emitted from the illumination light source and the position detection light emitted from the position detection light source; and the position detection light taken in from the side end A light guide plate that emits to the detection region and emits the illumination light to the side where the detection region is located;
A light-transmitting region that is provided between the light guide plate and the detection region and through which the illumination light and the position detection light are transmitted, and a wavelength at which at least a part of the position detection light is blocked while the illumination light is transmitted An intensity distribution changing layer in which selective light-shielding regions are distributed in an in-plane direction, and change an intensity distribution of an emitted light amount of the position detection light emitted from the light guide plate toward the detection region;
A photodetector comprising a light receiving portion arranged toward the detection region so as to receive the position detection light reflected by the target object;
A signal processing unit for detecting the position of the target object based on the detection result of the photodetector and the intensity distribution of the emitted light quantity of the position detection light;
An optical position detection device with an illumination function. The illumination light source is provided at a first side portion of the side end portion of the light guide plate,
In the intensity distribution changing layer, the formation density of the light-transmitting region is lower on the second side portion facing the first side portion at the side end portion than on the first side portion side. The optical position detection apparatus with an illumination function according to claim 1.   A dot-like reflective layer having a higher formation density on the second side portion side than the first side portion side is provided on the opposite side of the light guide plate from the illumination light emission side. The optical position detection apparatus with an illumination function according to claim 2.   The wavelength-selective light-shielding region is a dielectric multilayer film having a film configuration in which the illumination light is transmitted and at least a part of the position detection light is blocked, or at least one of the position detection light and the illumination light is transmitted. The optical position detection device with an illumination function according to any one of claims 1 to 3, wherein the optical position detection device is made of a metal oxide film having a composition in which a portion is cut off. A display device with a position detection function comprising the optical position detection device with an illumination function according to any one of claims 1 to 4,
An electro-optic panel that modulates the illumination light and generates an image in a region that overlaps the detection region in plan view is provided on the light emission plate emission side with respect to the light guide plate. Display device with position detection function. In the electro-optical panel, a switch image selected by the approach of the target object in the detection area is displayed,
The display device with a position detection function according to claim 5, wherein the translucent area is provided at a position overlapping the switch image in plan view.

Images