JP2010204788A - Illuminator and electrooptical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively constitute an optical position detecting means with low power consumption. <P>SOLUTION: A position detecting device 10 includes: position detection light sources 12A, 12B for emitting position detecting light beams L2a, L2b; a front surface 30a having a detection plane area 10P for emitting the position detection light beams; a photo detector 15 arranged in an area along the front surface and detecting at least a part of the reflection light of the position detection light beams from a detection object Ob which is arranged on the front surface in the detection plane area; and a control means for obtaining planar position information of the detection object in the detection plane area, based on the detection value of the reflection light by the photo detector. An optical detection azimuth range in the orthogonal direction of the front surface concerning the photo detector is smaller than an optical detection azimuth range in the direction along the front surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an illuminating device and an electro-optical device, and more particularly to a configuration of an illuminating device suitable for use in a display device including an optical position detecting unit.

  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 solves the above-described problems, and provides an illumination device that can be configured to reduce the cost and power consumption of an optical position detection unit, and an electro-optical device (display device) using the illumination device. It is to be realized.

  In view of such circumstances, the position detection device of the present invention is arranged in a position detection light source that emits position detection light, a surface that includes a detection plane region that emits the position detection light, and a region along the surface. And a light detector for detecting at least a part of the reflected light of the position detection light by the detection object arranged on the surface in the detection plane region, and a detection value of the reflected light by the light detector. Control means for obtaining planar position information of the detection object in the detection plane region, and a light detection azimuth angle range in a direction perpendicular to the surface of the photodetector is along the surface. It is characterized by being narrower than the light detection azimuth range in the selected direction.

  According to the present invention, the position detection light emitted from the position detection light source is reflected by the detection object disposed on the surface in the detection plane region, and at least a part of the reflected light is disposed in the region along the surface. The control unit obtains planar position information in the detection plane area of the detection object based on the detection value of the photodetector. In such a position detection device, since it is not necessary to provide a large number of elements and light guide structures in the vicinity of the display screen as in the prior art, the optical position detection means can be configured to be low in cost and low in power consumption. In particular, the position of an object that is farther from the surface to be detected than the intended height range because the light detection azimuth range in the direction perpendicular to the surface of the photodetector is narrower than the light detection azimuth range in the direction along the surface. Detection error, and a wider range within the detection plane area on the surface can be detected by the photodetector, so that detection omissions can be reduced, and light detection The number of vessels can be reduced.

  In one aspect of the present invention, the photodetector includes a light detection unit that detects the reflected light, and a light receiving unit that guides the reflected light to the light detection unit. Detection azimuth limiting means for limiting the light detection azimuth range to a direction orthogonal to the surface is provided. According to this, the light detection azimuth angle range according to the present invention can be easily realized by limiting the light detection azimuth angle range to a direction orthogonal to the surface by the detection azimuth limiting means provided in the light receiving unit. it can. In particular, since the light detection azimuth range in the direction orthogonal to the surface can be set accurately, erroneous detection due to reflected light from a height range that does not require detection on the surface can be reliably prevented.

  In another aspect of the present invention, the photodetector includes a light detection unit that detects the reflected light, and a light receiving unit that guides the reflected light to the light detection unit. Detection azimuth expanding means for expanding the light detection azimuth range in a direction along the surface is provided. According to this, the photodetection azimuth range of the above aspect of the present invention can be easily realized by enlarging the photodetection azimuth range in the direction along the surface by the detection azimuth expanding means provided in the light receiving unit. it can. In particular, the photodetection azimuth range in the direction along the surface can be accurately set according to the orientation of the detection plane area, so that detection omission can be reliably prevented and the number of photodetectors can be reduced. Further reduction can be achieved easily.

  In another aspect of the present invention, the photodetector includes a light detection unit that detects the reflected light and a light receiving unit that guides the reflected light to the light detection unit. Detection azimuth limiting means for limiting the detection azimuth angle range to a direction orthogonal to the surface and detection azimuth expanding means for expanding the light detection azimuth angle range in a direction along the surface are provided. According to this, by the detection azimuth limiting means and the detection direction expanding means provided in the light receiving section, the light detection azimuth angle range is limited to a direction orthogonal to the surface, and the light detection azimuth angle range is along the surface. By enlarging in the direction, range limitation and range expansion are performed in the direction orthogonal to the surface and the direction along the surface, respectively, so that the light detection azimuth angle range of the above aspect can be realized more easily.

  In the above invention, the detection azimuth limiting means may be composed of a light blocking material that blocks the reflected light. According to this, since the detection azimuth limiting means is formed of the light shielding material that blocks the reflected light, the light detection azimuth angle range can be easily limited.

  Moreover, it is preferable that the detection azimuth expanding unit is configured by a light deflection unit that expands the light detection azimuth range by deflecting the reflected light. The light detection azimuth range can be easily expanded by changing the traveling direction of the reflected light by utilizing the light refraction and reflection by the light deflecting means.

  In this case, it is preferable that the light deflecting unit is formed of a translucent material having a convex curved surface in a cross section along the surface of the surface opposite to the light detection unit. According to this, since the cross section along the surface of the surface opposite to the light detection unit is configured by the convex curved lens material, a wide azimuth angle in the direction along the surface by the convex curved lens surface. Since the reflected light within the range is collected within a narrow azimuth range, the light detection azimuth range can be reliably expanded with a simple configuration.

  In addition, the light deflecting unit is preferably formed of a translucent material in which a cross section along the surface of the surface on the light detection unit side is configured to be uneven, or the surface is a rough surface. . According to this, the reflected light incident on the lens material from the direction close to the end of the wide azimuth angle range in the direction along the surface is refracted by the surface on the side of the photodetection unit whose cross section along the surface is uneven. As a result, the light detection range is deflected to a narrow azimuth range in the direction along the surface and guided to the light detection unit, so that the light detection range can be reliably expanded with a simple configuration.

  In addition, as the light deflecting means, a lens material having the convex-concave cross section on the surface on the light detection unit side and the convex curved cross section on the surface opposite to the light detection unit is used. Is more desirable. In this case, the light detection azimuth in the direction along the surface is determined by the surface on the side of the light detection unit having the concavo-convex cross section and the surface on the side opposite to the light detection unit having the convex curved cross section. The angular range can be expanded reliably and significantly.

  In a certain aspect of the present invention, the control means applies a first light emission distribution constituted by the position detection light and a second light emission distribution different from the first light emission distribution to the detection plane region on the surface. Each of the output components of the light detectors formed from the first position detection light constituting the first light emission distribution and the second position detection constituting the second light emission distribution. Position information of the detection target is obtained based on an output component of the photodetector caused by light. According to this, 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 detection object 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.

  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.

  Further, the first light emission distribution and the second light emission distribution may be formed in a manner that can be distinguished from each other. For example, if they are formed by position detection lights that can be distinguished from each other, they are formed at the same time. It is also possible that the output components of the photodetectors are caused by any light emission distribution with respect to each other, such as being formed with a time difference if they are formed with position detection lights that cannot be distinguished from each other. This is done in a way that can be identified. Further, the first light emission distribution and the second light emission distribution may be composed of position detection light emitted from the same position detection light source, and are emitted from different position detection light sources. A light source for position detection may be used.

  Next, an electro-optical device according to the present invention is disposed in a position detection light source that emits position detection light, a surface including a detection plane region that emits the position detection light, and a region along the surface, A light detector for detecting at least a part of the reflected light of the position detection light by the detection object arranged on the surface in the detection plane region; and the detection based on a detection value of the reflected light by the light detector. A control means for obtaining planar position information of the object in the detection plane area; and a display area that at least partially overlaps the detection plane area to form the surface, or the surface And a photodetection azimuth range in a direction perpendicular to the surface of the photodetector is narrower than a photodetection azimuth range in a direction along the surface. It is characterized by.

  In one aspect of the present invention, a display screen area that optically exposes the display area and an edge area that surrounds the display screen area are provided on the surface, and the detection plane area is the display screen area. And the photodetector is disposed in the edge region. According to this, since the display area of the electro-optical panel is optically exposed and the detection plane area is arranged in the display screen area, the display image area within the detection plane area can be viewed while visually checking the display image in the display screen area. Instructions and operations can be performed at.

  In another aspect of the present invention, the control means includes a first light emission distribution constituted by the position detection light and a second light emission distribution different from the first light emission distribution in the detection plane region on the surface. Each of the output components of the light detectors formed from the first position detection light constituting the first light emission distribution and the second position detection constituting the second light emission distribution. Position information of the detection target is obtained based on an output component of the photodetector caused by light.

FIG. 3 is a schematic cross-sectional view schematically showing the configuration of the first embodiment of the position detection device and the electro-optical device. The schematic plan view which shows the structure of the surface side of 1st Embodiment typically. The schematic fragmentary sectional view which shows typically the structure by the side of the surface of 1st Embodiment. The longitudinal cross-sectional view (a) and horizontal cross-sectional view (b) of the photodetector of 1st Embodiment. The longitudinal cross-sectional view (a) and horizontal cross-sectional view (b) of the photodetector of 2nd Embodiment. The cross-sectional view of the photodetector which shows the structural example applicable to each embodiment. The longitudinal cross-sectional view (a) and cross-sectional view (b) of the photodetector of 3rd Embodiment. The cross-sectional view of the photodetector which shows the structural example applicable to each embodiment. The schematic block diagram which shows the whole structure of the control system of a position detection apparatus. The timing chart which shows the signal of each part at the time of the detection of a position detection apparatus. The block diagram which shows the connection relation of a control part and each light source. The schematic fragmentary sectional view which shows the mode at the time of the detection of a position detection apparatus. The schematic plan views (a) and (b) which show the example of the detection range of a position detection apparatus.

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

[First embodiment]
FIG. 1 is a schematic cross-sectional view schematically showing a configuration of a position detection device and an electro-optical device according to the first embodiment of the present invention, and FIG. 2 is a view of the position detection device and the electro-optical device from the detection side (viewing side). It is a schematic plan view which shows a mode typically.

  The electro-optical device 100 according to the present embodiment includes an illumination light source 11 that emits illumination light L1, position detection light sources 12A and 12B that emit position detection light L2a and L2b, and a first light incident on the illumination light L1. Light plate 13A, second light guide plate 13B on which position detection lights L2a and L2b are incident, reflector 14 arranged behind light guide plates 13A and 13B, and light detection arranged on the emission side of the position detection light And a container 15. The light guide plates 13A and 13B are made of a transparent light guide such as acrylic resin or polycarbonate resin. The first light guide plate 13A includes a first light incident surface 13aa which is an end surface of one side, a light emitting surface 13ac which is adjacent to and intersects with the light incident surface (orthogonal in the illustrated example), and the light emitting surface. It has a back surface 13ad opposite to 13ac. The second light guide plate 13B includes second light incident surfaces 13ba and 13bb that face each other, a light emitting surface 13bc that is adjacent to and intersects with these light incident surfaces (orthogonal in the illustrated example), and the light. A back surface 13bd opposite to the exit surface 13bc. Furthermore, on the light exit side of the light guide plates 13A and 13B, optical diffusers such as a light diffusing plate for equalizing illumination light and a condensing plate such as a prism sheet for enhancing the directivity of the illumination light, if necessary. The sheet 16 is appropriately arranged.

  In the electro-optical device 100, the position detection device 10 includes position detection light sources 12A and 12B, a second light guide plate 13B, and a photodetector 15. An electro-optical panel 20 made of a transmissive liquid crystal display or the like is disposed on the light output side of the position detection lights L2a and L2b of the light guide plate 13B. 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. 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 that each pixel is in a predetermined transmission state.

  The electro-optical panel 20 has a display area in which the plurality of pixels are arranged, and the display area is planarly overlapped with a range where the illumination light L1 of the light emission surface 13ac of the light guide plate 13A is emitted. Be placed. Moreover, it arrange | positions so that it may planarly overlap with the range from which position detection light L2a and L2b of the light-projection surface 13bc of the light-guide plate 13B are radiate | emitted.

  On the opposite side of the electro-optical panel 20 from the position detection light sources 12A and 12B and the light guide plate 13B, a light-transmitting front panel 30 is disposed. The outer surface of the front panel 30 (on the side opposite to the electro-optical panel 20). The photodetector 15 is disposed on the surface. 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. Here, the surface 30a of the cover plate 30 constitutes the surface of the above-described invention of the present invention from which the position detection light L2a and L2b are emitted in the position detection device 10, but the cover plate 30 itself constituting this surface is essential. Instead of the configuration, for example, the surface may be configured by a surface on the viewing side of the electro-optical panel 20.

  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). Normally, a plurality of illumination light sources 11 are arranged along the first light incident surface 13aa (that is, along the side of the light guide plate 13A). Thereby, the uniformity of the luminance of the illumination light L1 emitted from the light emission surface 13ac of the first light guide plate 13A can be improved.

  The position detection light sources 12A and 12B are composed of light emitting elements such as LEDs (light emitting diodes), for example, and emit position detection lights L2a and L2b, for example, infrared rays in response to a drive signal output from a drive circuit (not shown). The position detection light is not particularly limited, but is preferably one that can be detected separately from 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.

  The position detection light preferably has a wavelength range that is efficiently reflected by the target object Ob of the present invention. For example, if the target object Ob is a human body such as a finger, it is desirable to use infrared rays with high reflectivity on the surface of the human body (particularly near infrared rays close to the visible light region). The position detection light sources 12A and 12B are configured to emit position detection light from different positions. In the illustrated example, the position detection lights L2a and L2b are emitted to the opposite sides toward the light incident surfaces 13ba and 13bb facing each other of the light guide plate 13B. It is preferable that a plurality of the position detection light sources 12A and 12B are arranged along the side of the light guide plate 13B on the light incident surfaces 13ba and 13bb.

  In the first light guide plate 13A of the present embodiment, the ratio of the amount of light emitted from the light exit surface 13ac to the internally propagated light from the first light incident surface 13aa side toward the outer edge portion 13ab on the opposite side is monotonic. It has increasing light guide properties. The light guide characteristics include, for example, the area of a fine refracted surface for light deflection or light scattering formed on the light exit surface 13ac or the back surface 13ad of the first light guide plate 13A, the formation density of the printing layer, and the like. This is realized by gradually increasing the scattering rate of the light scattering structure constituted by the above toward the internal propagation direction. By providing such a light guide characteristic, the illumination light L1 incident from the first light incident surface 13aa is emitted almost uniformly from the light emitting surface 13ac, and as a result, the first light guide plate 13A serves as a planar light source. Configured to work. The illumination light L1 passes through the electro-optical panel 20 and is emitted from the front panel 30 to the viewing side.

  In the present embodiment, an inclined surface 13ag is provided on the surface portion on the light emitting side adjacent to the first light incident surface 13aa (the outer peripheral portion of the light emitting surface 13ac), whereby the first light guide plate 13A In the outer peripheral portion, the thickness of the first light guide plate 13A is gradually increased toward the first light incident surface 13aa. The height of the first light incident surface 13aa is increased by suppressing the increase in the thickness of the portion where the light exit surface 13ac is provided by the light incident structure having the inclined surface 13ag, and the light emission region of the illumination light source 11 is increased. It is formed to correspond to the height. This is to reduce the thickness of the first light guide plate 13A in order to meet the recent demand for thin display devices, and to collect emitted light from a light emitting element (illumination light source 11) that has not been miniaturized. This is to improve the illumination brightness by increasing the illumination efficiency.

  In the second light guide plate 13B, the position detection light L2a is incident from the second light incident surface 13ba, propagates in the opposite direction, and is gradually emitted from the light emitting surface 13bc. The light L2b is configured to enter from the second light incident surface 13bb, propagate through the inside toward the opposite side, and gradually exit from the light emitting surface 13bc. The light guide characteristics of the light guide plate 13B are also set by appropriately providing the same light scattering structure as described above. These position detection lights L2a and L2b are transmitted through the electro-optical panel 20 and emitted from the front panel 30 to the detection side (viewing side).

  As shown in FIG. 2, a frame body 101 having an opening 101 a for determining a display screen area of the electro-optical device 100 is arranged on the detection side of the front panel 30, and faces the display screen area of the frame body 101. The photodetector 15 is exposed at a part of the opening edge (corresponding to the edge region) 101b so as to face the display screen region. This photodetector 15 has a detector main body 15A and a light receiving member 15B. The detector main body 15A is arranged inside the frame body 101, and the light receiving member 15B is configured to guide the reflected light to the detector main body 15A and is exposed to the opening edge 101b.

  In the display screen region that is optically exposed by the opening 101a, the illumination light L1 is emitted after passing through the electro-optical panel 20 as described above, so that the display region of the electro-optical panel 20 from the viewing side. The predetermined image formed by can be visually recognized. In the display screen area, a detection plane area 10P from which the position detection lights L2a and L2b are emitted from the surface is provided. The detection plane area 10P is an area where the position detection lights L2a and L2b are emitted as described above, and a detection object such as a finger or a pen tip is placed on the surface 30a of the cover plate 30 in the detection plane area 10P. When arranged, when the photodetector 15 detects the reflected light of the detection object, planar position information in the detection plane region 10P can be obtained as described later. In the present application, the planar position information refers to position information along at least one direction in the plane of the detection plane area.

  In the present embodiment, as shown in FIG. 2, the light detection azimuth angle range of the photodetector 15 is along the surface 30a of the detection plane region P (in the illustrated example, the surface of the cover plate 30). The direction is a wide-angle range 10T that is wider than the original range 10S of the detector body 15A and covers the entire detection plane region 10P. Also, as shown in FIG. 3, the direction orthogonal to the surface 30a is narrower than the original range 10Q of the detector body 15A and has a limited height range on the surface 30a (for example, 0 to 15 mm, particularly The range is 10R corresponding to about 1 to 10 mm.

  As described above, the light detection azimuth angle range of the photodetector 15 of the present embodiment is formed narrower in the direction orthogonal to the surface 30a than in the direction along the surface 30a. The reason for providing such a light detection azimuth angle range is as follows. As shown in FIG. 12, when the light detection azimuth angle range 10Q in the direction orthogonal to the surface 30a of the photodetector 15 is large, the position of the detection object Ob originally arranged on the surface 30a in the detection plane region 10P. Although it is supposed to be a position detection device for detecting P1, it detects the reflected light from the position P2 of the detection object Ob ′ arranged outside the detection plane region 10P or at a position separated from the surface 30a. This leads to erroneous detection of the detection object. On the other hand, as shown in FIG. 13A, when the photodetector 15 is disposed adjacent to the detection plane range 10P, if the light detection azimuth range 10S in the direction along the surface 30a is narrow, the detection plane Since the entire region 10P cannot be covered, undetectable regions 10Px and 10Py are generated in the detection plane region 10P. In this case, it is necessary to increase the number of the light detectors 15 or to separate the light detectors 15 from the detection plane region 10P by the distance Lx as shown in FIG. 13B. Increases the cost. In the latter case, the sensitivity is lowered and the size of the apparatus is increased.

  In the present embodiment, the light detection azimuth range is made narrower in the direction perpendicular to the surface 30a than in the direction along the surface 30a for the reasons described above. For this purpose, the light receiving member 15B is provided on the light receiving surface side of the detector main body 15A. 4A is an enlarged longitudinal sectional view of the photodetector 15, and FIG. 4B is an enlarged transverse sectional view of the same. In the present embodiment, the detector main body 15A covers the light detection unit 15aa composed of a photodiode element such as a PIN diode chip, the base unit 15ab on which the light detection unit 15aa is mounted and fixed, and the light detection unit 15aa. And a window portion 15ac made of a transparent sealing material to be sealed. The base portion 15ab has a housing portion formed in a concave shape, and the light detection portion 15aa is fixed to the bottom of the housing portion.

  In the present embodiment, a light receiving member 15B is provided on the window 15ac (light receiving surface) of the detector main body 15A, and the light receiving member 15B is configured to guide reflected light to the light receiving surface of the detector main body 15A. The The light receiving member 15B has a structure in which light shielding portions 15ba and 15bb are arranged on both sides in a direction perpendicular to the surface 30a (vertical direction in FIG. 4A), and a light transmitting portion 15bc is arranged therebetween. The light shielding portions 15ba and 15bb only need to be made of a material that does not transmit reflected light. However, the light shielding portions 15ba and 15bb are made of a light absorbing material such as a black resin (a material that absorbs reflected light) in order to prevent reflection at the light shielding portion itself. It is preferable. Moreover, although the translucent part 15bc should just be comprised with translucent materials, such as an acrylic resin which permeate | transmits reflected light, it is comprised with the transparent material which has the high transmittance | permeability (for example, 80% or more) with respect to reflected light. Is desirable. The light shielding portion and the light transmitting portion are fixed by various methods such as adhesion, integral molding (two-color molding, etc.), welding, and the like. The light shielding portions 15ba and 15bb constitute detection azimuth limiting means for restricting the light detection azimuth angle range 10R in the direction orthogonal to the surface 30a of the photodetector 15 from the original range 10Q of the detection main body 15A. In this embodiment, the detection azimuth limiting means limits the azimuth angle range on both sides in the direction orthogonal to the surface 30a with respect to the original range 10Q by the light shielding portions 15ba and 15bb.

  Further, as shown in FIG. 4B, the light receiving member 15B has a shape in which a surface opposite to the light detection portion 15aa is formed in a convex curved surface, and a light transmitting portion having a planar shape of the shape. Reference numeral 15bc functions as a lens material that collects the reflected light incident from the outside in a narrower incident angle range. The light shielding portions 15ba and 15bb also have a planar shape as described above, and completely cover both sides in the direction orthogonal to the surface 30a of the light transmitting portion 15bc. In the present embodiment, the direction along the surface 30a (FIG. 4 (FIG. 4)) due to the light condensing action of the light receiving member 15B due to the surface of the light transmitting portion 15bc opposite to the light detecting portion 15aa being convex. Reflected light incident from a wide range 10T in the vertical direction (b) is accommodated in the original light detection azimuth angle range 10S of the detector body 15A and can be detected. Therefore, the translucent part 15bc constitutes a detection azimuth expanding means for expanding the light detection azimuth angle range 10T in the direction along the surface 30a of the photodetector 15 more than the original range 10S. In this embodiment, the detection azimuth expanding means expands the azimuth angle range on both sides in the direction along the surface 30a with respect to the original range 10S by the convex curved outer surface of the light transmitting portion 15bc.

  In the configuration described in the present embodiment, the first light guide plate 13A is disposed on the electro-optical panel 20 side, and the second light guide plate 13B is disposed on the opposite side so as to overlap each other in a plane. However, conversely, the second light guide plate 13B may be disposed on the electro-optical panel 20 side, and the first light guide plate 13A may be disposed on the opposite side. In the above configuration, the light incident surface 13aa and the illumination light source 11 are disposed on the first light guide plate 13A, and the light incident surface 13ba and the position detection light source 12A are disposed on the second light guide plate 13B. Although the sides are arranged on the same side, they may be arranged on different sides (opposite sides or sides orthogonal to each other).

  In the present embodiment, it is preferable that the surface of the window portion 15ac of the detector main body 15A and the surface of the light transmitting member 15B on the light detection portion 15aa side are bonded and fixed with a transparent adhesive. They may be simply brought into contact with another fixing means (not shown) (adhesive tape, holder, etc.), or may be arranged to face each other with a slight gap.

  In the first embodiment configured as described above, the illumination light L1 gradually enters the first light guide plate 13A from the first light incident surface 13aa and then gradually propagates through the interior of the light emitting surface 13ac. And then passes through the electro-optic panel 20 and then passes through the front panel 30 and exits to the viewing side in the display screen area. The illumination light L1 is configured so that a display image formed by controlling the light transmittance of each pixel of the electro-optical panel 20 can be visually recognized.

  The first position detection light L2a is gradually emitted from the entire light emission surface 13ac into a planar shape while propagating through the second light incident surface 13ba through the second light guide plate 13A, and passes through the electro-optical panel 20. Then, the light passes through the front mounting plate 30 and exits in the detection plane region 10P. At this time, if the target object Ob exists on the surface 30 a of the cover plate 30, the light reflected by the target object Ob is detected by the photodetector 15 disposed on the cover plate 30.

  Further, the position detection light L2b is also emitted from the entire light emitting surface 13bc into a planar shape while propagating through the inside after being incident on the second light guide plate 13B from the second light incident surface 13ba. And it permeate | transmits the surface mounting plate 30, and inject | emits in the detection plane area | region 10P. At this time, if the target object Ob exists on the surface of the cover plate 30, the reflected light from the target object Ob is a position along the surface 30a of the cover plate 30 and a position other than the detection plane region 10P (in the illustrated example). It is detected by the photodetector 15 arranged at a position adjacent to the region 10P. The amount of reflected light detected by the photodetector 15 includes the contribution of the plurality of position detection lights L2a and L2b.

  Next, a method for acquiring position information of the target object Ob based on detection by the photodetector 15 will be described. There are various possible methods for acquiring the position information. For example, as an example, the ratio of the attenuation coefficients of the two detectors of the position detection light in the photodetector 15 is obtained, and the attenuation coefficient is obtained. There is a method of obtaining the position coordinates of the detection object Ob in the predetermined direction in the detection plane region 10P by obtaining the propagation distance of both position detection lights from the ratio of the coefficients.

  More specifically, the emission light amount distribution of the first position detection light L2a emitted from the surface 30a by one or a plurality of first position detection light sources 12An (n = 1 to k; k is an arbitrary natural number). A certain first light emission distribution D1 is formed in the detection plane region 10P and emitted from the surface 30a by one or a plurality of second position detection light sources 12Bn (n = 1 to k; k is an arbitrary natural number). A case where the second light emission distribution D2 that is the emission light amount distribution of the second position detection light L2b is formed in the detection plane range 10P will be described. In this case, the first light emission distribution D1 is, for example, a distribution in which the amount of emitted light gradually decreases toward one side (the right side in FIG. 1) in the X direction (see FIG. 1), and the second light emission distribution D2 Is a distribution in which the amount of emitted light gradually decreases toward the other side in the X direction (left side in FIG. 1). These distributions D1 and D2 are realized by obtaining appropriate emission modes by the light scattering structure while the position detection lights L2a and L2b are attenuated in the process of propagating through the light guide plate 13B. Here, the control amount (for example, current amount), the conversion coefficient and the emitted light amount of the first position detection light source 12An are Ia, ka and Ea, the control amount (current amount) of the second position detection light source 12Bn, and the conversion coefficient. Assuming that 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 position detection light L2a are fa and Ha, and the attenuation coefficient and the detected light amount of the second position detection light L2b are fb and Hb, the following equations (3) and (4) ) Holds.

  Ha = fa · Ea = fa · k · Ia (3)

  Hb = fb · Eb = fb · k · Ib (4)

  Therefore, if Ha / Hb, which is the ratio of the detected light amounts of the two position detection lights L2a and L2b, can be detected by the ratio of the output components of the photodetector 15 caused by the two light emission distributions D1 and D2, respectively, Ha / Hb = (Fa · Ea) / (fb · Eb) = (fa / fb) · (Ia / Ib), so if the value corresponding to the ratio Ea / Eb of the emitted light quantity or the ratio Ia / Ib of the control amount is known. The ratio fa / fb of the damping coefficient is found from 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), it changes according to the inclination of the first light emission distribution D1 and the second light emission distribution D2 depending on the position of the detection object Ob on the X coordinate. 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 has a positive correlation with (1-x) / x with respect to the coordinate x in the X direction of the detection object Ob. 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, a first group of position detection light sources 12An and a second group of position detection light sources 12Bn are provided separately, and the position detection lights L2a and L2b can be identified and detected. Good. 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.

  FIG. 10 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. The detection signal E0 of the light detector 15 is a response having a suitable time delay td with respect to the control signals S1 and S2, which is a detection component of the position detection light L2a (due to the first light emission distribution D1). The sum of the output component) E1 and the detection component E2 of the position detection light L2b (the output component resulting from the second light emission distribution D2).

  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. 9, the control signals S1 and S2 and the drive setting signals I1 and I2 are output to the drive units IA and IB from the control unit S operating according to the clock signal CLK, and the drive units IA and IB receive these signals. Based on this, 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. Here, the control part S and the analysis part P correspond to the above-mentioned control means.

  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 Ib is controlled to be 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, since Ib = Im · fb / (fa + fb) according to the equation (5), when fb / (fa + fb) = α, the ratio of the attenuation coefficient is given by fa / fb = (1−α) / α. Is obtained.

  In the case of the present embodiment, as described above, the position information in the X direction of the detection target Ob in the detection plane region 10P is obtained by using the first light emission distribution D1 and the second light emission distribution D2 as described above. By using the obtained detection components E1 and E2, respectively, 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. it can. On the other hand, as for the position information in the Y direction of the detection object Ob in the detection plane region 10P, the third light emission distribution D3 (having the emitted light amount distribution inclined to one side in the Y direction) and the X direction, The coordinate y can be obtained by obtaining the detection components E1 and E2 in the same manner as described above using the fourth light emission distribution D4 (having the emitted light amount distribution inclined to the other side in the Y direction).

  As a configuration for forming each of the light emission distributions D1 to D4, for example, a plurality of first position detection light sources 12An and a plurality of second plurality of position detection light sources 12Bn shown in FIG. S is controlled. That is, as shown in FIG. 11, the current values Ia1, Ia2, Ia3,..., Iak, which are control amounts of the position detection light source 12An (n = 1 to k), are respectively set as drive setting signals Ia1, Ia2, Ia3. ,..., Iak is supplied from the control unit S to the driving units IA1, IA2, IA3,..., IAk, and similarly, the control amount of each of the position detection light sources 12Bn (n = 1 to k) is controlled. , Ibk and drive setting signals Ib1, Ib2, Ib3,..., Ibk from the control unit S to the drive units IB1, IB2, IB3,. Control by giving. For example, 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. The coordinate x is obtained from the above, 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.

  In the above configuration, the first position detection light source 12An and the second position detection light source 12Bn form different distributions. However, even if the position detection light sources are not separately prepared, The first light emission distribution D1 by the position detection light L2a and the second light emission distribution D2 by the position detection light L2b are formed at different timings by the same plurality of position detection light sources 12, and the detected light quantity is obtained at each timing. However, the above discrimination becomes possible. For example, unlike the present embodiment in which the position detection light is emitted through the light guide plate 13B, a plurality of position detection light sources arranged in the detection plane range 10P are arranged behind the surface 30a, The position detection light emitted from the plurality of position detection light sources may be directly emitted from the surface 30a. In this case, the first light emission distribution D1 and the second light emission distribution D2 can be formed by changing the distribution of the emitted light quantity of the plurality of position detection light sources. Then, for example, the first light emission distribution D1 and the second light emission distribution D2 are alternately formed, and a certain process is performed based on the detection signal of the photodetector 15 output in response thereto.

  According to the present embodiment, in particular, the planar position information of the detection object Ob on the display screen is detected while illuminating and displaying the electro-optical panel 20 that controls the light modulation state for each pixel. be able to. At this time, the position detection lights L2a and L2b are emitted from the surface 30a with a predetermined distribution in the detection plane area 10P, and the light reflected by the detection object Ob is detected by the light detector 15 to be detected. Since the planar position information of the object Ob can be obtained, the number of elements for position detection is greatly reduced compared to the conventional method of arranging a large number of light sources, photodetectors, optical switches, etc. on the display screen. Thus, the structure can be greatly simplified, the manufacturing cost can be reduced, and the power consumption can be reduced.

  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 level of the detected light amount (output component) due to the structure, for example, the light guide characteristics of the light guide plate 13B, fluctuations or variations in the light transmittance in the optical sheet 16, the electro-optical panel 20, the cover plate 30, etc. It is possible to eliminate the effects of fluctuations and variations. 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.

  In the present embodiment, since the plurality of illumination light sources 11 are provided together with the plurality of position detection light sources 12An and 12Bn, and the electro-optical panel 20 is illuminated by the plurality of illumination light sources 11, the position detection device 10 is illuminated. The electro-optical device 100 with the unit can be compactly incorporated.

  In this 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. Although the position information of the detection object Ob is derived based on the ratio of Hb, the present invention is not limited to the case where the position information is derived based on the ratio of the detected light amounts Ha and Hb. For example, since there is a correlation between the coordinates x and y of the detection target Ob and the difference Ha−Hb between the detected light amounts, it is also possible to derive the 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−Mb · Hb (Ma and Mb are coupling coefficients, respectively) If the position information is derived using both the detected light amounts Ha and Hb, which are output components respectively resulting from both light emission distributions, such as using the position information, the position information can be derived more accurately and stably.

  In the present embodiment, the configuration including both the detection azimuth limiting means and the detection azimuth expanding means of the present invention has been described. However, in the present invention, the light detection azimuth angle range in the direction orthogonal to the surface 30a is the surface 30a. In this embodiment and other embodiments or configuration examples, either of the detection azimuth limiting means and the detection azimuth expansion means may be provided as such a configuration. It's enough.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5A is a schematic longitudinal sectional view of the photodetector of the present embodiment, and FIG. 5B is a schematic transverse sectional view thereof. Since the second embodiment is configured in the same manner as in the first embodiment except for the structure of the photodetector 15 ', the same parts are denoted by the same reference numerals, and description thereof is omitted.

  In the photodetector 15 ′ of this embodiment, a different light receiving member 17B is connected to a detector body 15A similar to that of the first embodiment. In the light receiving member 17B, light-shielding portions 17bai, 17bbi, 17bao, and 17bbo are attached to a light-transmitting portion 17bc disposed on the light-receiving surface of the detector main body 15A, and light detection in a direction perpendicular to the surface 30a is performed by these light-shielding portions. A narrow range 10R is realized by limiting the azimuth range. Here, the light shielding portions 17bai and 17bbi are disposed between the detector main body 15A and the light transmitting portion 17bc, and the light shielding portions 17bao and 17bbo are disposed on the outer surface of the light transmitting portion 17bc opposite to the detector main body 15A. The Further, the light shielding portions 17bai and 17bao are arranged on the upper side of the light transmitting portion 17bc, restrict the light detection azimuth range on the side away from the surface 30a, and the light shielding portions 17bbi and 17bbo are arranged on the lower side of the light transmitting portion 17bc. The light detection azimuth range on the surface 30a side is limited.

  Also in the present embodiment, as shown in FIG. 5B, the cross-sectional shape along the surface 30a of the surface opposite to the light detection unit 15aa of the translucent part 17bc is configured as a convex curved surface. Thus, the light detection azimuth range 10T along the surface 30a is configured to be a wide angle.

  In addition, the said light transmission part and the light-shielding part can use the thing similar to 1st Embodiment, and the attachment aspect between them can also be made the same as the above.

  FIG. 6 is a cross-sectional view of a photodetector 15 ′ showing a configuration example that can be commonly applied to the present embodiment and other embodiments. The photodetector 15 ′ has a structure substantially similar to that of the second embodiment, but a cross-sectional shape along the surface 30a is formed along the surface 30a on the surface of the light transmitting portion 17bc on the light detecting portion 15aa side. The difference is that a surface uneven structure 17bd configured to be uneven in the direction (vertical direction in FIG. 6) is provided.

  In the illustrated example, the surface concavo-convex structure 17bd has a triangular concavo-convex shape in cross section along the surface 30a, and the cross-sectional shape as it is in a direction orthogonal to the surface 30a (a direction orthogonal to the paper surface of FIG. 6). It has an extended structure. Since the reflected light that has entered the light transmitting portion 17bc is refracted by the surface uneven structure 17bd and then enters the detector body 15A, it enters from the vicinity of the end of the light detection azimuth angle range 10T in the direction along the surface 30a. Even the reflected light with a high incident angle is deflected by the surface uneven structure 17bd to become a reflected light with a low incident angle and can be detected by the light detection unit 15aa. Therefore, this surface concavo-convex structure 17bd also corresponds to the detection direction expanding means of the present invention. The surface concavo-convex structure 17bd is not limited to the triangular concavo-convex shape in the illustrated example, but may be a rectangular concavo-convex structure, a corrugated concavo-convex structure, or the like.

  The surface uneven structure 17bd refracts reflected light by forming an interface having different refractive indexes in an uneven shape, so that the surface (light receiving surface) of the window portion 15ac of the detector body 15A and the light transmitting portion As long as the refractive index is different, the relationship between the 17bc and the surface on the light detection unit 15aa side is opposed to each other with a gap between them even if they are bonded with a transparent adhesive or are in contact with each other. May be. This also applies to the configuration example shown in FIG.

  In the present configuration example, since the cross-sectional shape along the surface 30a of the surface opposite to the light detection unit 15aa of the translucent part 17bc is a convex curved surface, the detection direction based on the above-described condensing function of the surface In addition to the effect of expanding the detection azimuth, the effect of expanding the detection orientation by the surface uneven structure 17bd is achieved. However, the surface uneven structure 17bd is formed on the surface on the light detection unit 15aa side in a state where the condensing function of the surface is eliminated by flattening the surface of the light transmission unit 17bc opposite to the light detection unit 15aa. Even just doing, the photodetection azimuth range can be expanded in the direction along the surface 30a.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 7A is a schematic longitudinal sectional view of the photodetector of this embodiment, and FIG. 7B is a schematic transverse sectional view thereof. In the third embodiment, the structure is the same as that of the first embodiment except for the structure of the photodetector 15 ″, so the same parts are denoted by the same reference numerals and the description thereof is omitted.

  The photodetector 15 ″ of this embodiment includes a detector main body 15A similar to the above and a light receiving member 18B. The light receiving member 18B includes light shielding portions 18ba and 18bb and a light transmitting portion 18bc. The parts 18ba and 18bb are made of the same material as that of the above embodiment and are similarly attached to the light transmitting portion 18bc. The light transmitting portion 18bc is also made of the same material as that of the above embodiment.

  The light transmitting portion 18bc is configured so that the surface on the light detecting portion 15aa side is flat (generally, a surface shape corresponding to the surface of the window portion 15ac of the detector main body 15A), whereas the light detecting portion 15aa The opposite surface is formed in a convex curved surface shape (that is, in a convex lens shape) in both the direction orthogonal to the surface 30a and the direction along the surface 30a. Correspondingly, the light shielding portions 18ba and 18bb are arranged so as to wrap around the peripheral portion of the convex curved surface on the opposite side of the light detecting portion 15aa of the light transmitting portion 18bc, and in a direction orthogonal to the surface 30a. The light detection azimuth range 10R is limited from both sides.

  FIG. 8 is a cross-sectional view of a photodetector 15 ″ showing a configuration example that can be commonly applied to the present embodiment and other embodiments. In this photodetector 15 ″, the light detector of the translucent portion 18bc. The difference is that the surface on the 15aa side is a rough surface (surface formed in a fine uneven shape) 18bd. The rough surface 18bd can be formed by sandblasting, grinding, etching, or the like.

  In this configuration example, the reflected light incident on the light transmitting portion 18bc is scattered by the rough surface 18bd when emitted from the light transmitting portion 18bc toward the detector main body 15A, and thus light detection in the direction along the surface 30a is performed. Even the high incident angle reflected light incident from the side near the end of the azimuth angle range 10T is scattered by the rough surface 18bd, so that it can be detected by the light detection unit 15aa as a low incident angle reflected light. Become. Therefore, this rough surface 18bd also corresponds to the detection direction expanding means of the present invention.

  In this configuration example, since the cross-sectional shape along the surface 30a of the surface opposite to the light detection unit 15aa of the light transmitting unit 18bc is a convex curved surface, the detection direction based on the above-described light collecting function of the surface In addition to the enlargement effect, the detection orientation enlargement effect by the rough surface 18bd is achieved. However, the surface on the light detection unit 15aa side is simply a rough surface 18bd in a state in which the light condensing function of the surface is eliminated by flattening the surface of the light transmission unit 18bc opposite to the light detection unit 15aa. However, the light detection azimuth angle range can be expanded in the direction along the surface 30a.

  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. For example, in the above-described embodiment, two light guide plates are arranged adjacent to each other and are used by overlapping them in a predetermined order in a plane, but the two light guide plates may be stacked in reverse order, and depending on circumstances. May be arranged on both sides of the electro-optical panel. For example, an illumination light guide plate may be disposed behind the electro-optical panel, and a position detection light guide plate may be disposed on the viewing side of the electro-optical panel. In addition to the light emitting structure using the light guide plate, for example, a structure for emitting position detection light directly from the surface using a plurality of position detection light sources arranged in the detection plane range in the same manner as a direct illumination unit. It is also possible.

  Furthermore, as the position detection method in the above embodiment, a method for obtaining position information based on the light amount ratio corresponding to the attenuation rate of the light amount that changes in accordance with the difference in propagation distance between the two types of position detection light is illustrated. The invention is not limited to the detection method described above, such that the position information can be obtained from a phase difference that changes in accordance with the difference in propagation distance between the two types of position detection light.

DESCRIPTION OF SYMBOLS 10 ... Illuminating device, 11 ... Light source for illumination, 12A, 12B ... Light source for position detection, 13A, 13B ... Light guide plate, 13aa ... First light incident surface, 13ag ... Inclined surface, 13ba ... Second light incident surface, 13ac, 13bc ... light emitting surface, 13ad, 13bd ... back surface, 14 ... reflecting plate, 15 ... light detector, 15A ... detector body, 15aa ... light detecting portion, 15B ... light receiving member, 15ba, 15bb ... light shielding portion, 15bc DESCRIPTION OF SYMBOLS ... Translucent part, 16 ... Optical sheet, 20 ... Electro-optical panel, 30 ... Front panel, L1 ... Illumination light, L2a, L2b ... Position detection light, 100 ... Electro-optical apparatus

Claims (12)

A position detection light source that emits position detection light;
A surface having a detection plane region for emitting the position detection light;
A photodetector that is disposed in a region along the surface and detects at least a part of the reflected light of the position detection light by a detection object disposed on the surface in the detection plane region;
Control means for obtaining position information on the surface of the detection object in the detection plane area based on a detection value of the reflected light by the photodetector;
Comprising
The position detection device according to claim 1, wherein a light detection azimuth range in a direction orthogonal to the surface of the photodetector is narrower than a light detection azimuth range in a direction along the surface.   The light detector includes a light detection unit that detects the reflected light and a light receiving unit that guides the reflected light to the light detection unit. The light detection unit includes the light detection azimuth range as the surface. The position detection device according to claim 1, further comprising a detection azimuth limiting unit that limits the direction to an orthogonal direction.   The photodetector includes a light detection unit that detects the reflected light, and a light receiving unit that guides the reflected light to the light detection unit. The light detection unit has the light detection azimuth range on the surface. The position detection apparatus according to claim 1, further comprising a detection azimuth expanding unit that expands in a direction along the line.   The light detector includes a light detection unit that detects the reflected light and a light receiving unit that guides the reflected light to the light detection unit. The light detection unit includes the light detection azimuth range as the surface. The position detection apparatus according to claim 1, further comprising: a detection azimuth limiting unit that limits the direction to an orthogonal direction; and a detection azimuth expansion unit that expands the light detection azimuth range in a direction along the surface. .   The position detection apparatus according to claim 2, wherein the detection azimuth limiting unit is formed of a light blocking material that blocks the reflected light.   5. The position detection device according to claim 3, wherein the detection azimuth expanding unit includes a light deflection unit that expands the range of the light detection azimuth angle by deflecting the reflected light.   The position detecting device according to claim 6, wherein the light deflecting unit is formed of a translucent material having a convex curved surface in a cross section along the surface of the surface opposite to the light detecting unit.   The light deflecting means is formed of a light-transmitting material in which a cross section along the surface of the surface on the light detection unit side is configured to be uneven, or the surface is a rough surface. The position detection device according to claim 6 or 7.   The control means forms a first light emission distribution constituted by the position detection light and a second light emission distribution different from the first light emission distribution in the detection plane region on the surface, and The output component of the photodetector due to the first position detection light constituting the light emission distribution and the second detector of the photodetector due to the second position detection light constituting the second light emission distribution. The position detection apparatus according to claim 1, wherein position information of the detection target is obtained based on an output component. A position detection light source that emits position detection light;
A surface having a detection plane region for emitting the position detection light;
A photodetector that is disposed in a region along the surface and detects at least a part of the reflected light of the position detection light by a detection object disposed on the surface in the detection plane region;
Control means for obtaining planar position information in the detection plane area of the detection object based on a detection value of the reflected light by the photodetector;
An electro-optic panel that includes a display area that at least partially overlaps the detection plane area in a planar manner, configures the surface, or is disposed behind the surface;
Comprising
An electro-optical device, wherein a light detection azimuth range in a direction orthogonal to the surface of the photodetector is narrower than a light detection azimuth range in a direction along the surface.   A display screen area for optically exposing the display area and an edge area surrounding the display screen area are provided on the surface, and the detection plane area is disposed in the display screen area, and the photodetector The electro-optical device according to claim 9, wherein the electro-optical device is disposed in the edge region.   The control means forms a first light emission distribution constituted by the position detection light and a second light emission distribution different from the first light emission distribution in the detection plane region on the surface, and The output component of the photodetector due to the first position detection light constituting the light emission distribution and the second detector of the photodetector due to the second position detection light constituting the second light emission distribution. 11. The electro-optical device according to claim 9, wherein position information of the detection target is obtained based on an output component.

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