JP2014021789A - Input device, and input system including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an input device without malfunction and having a new constitution in which a light receiving element can be installed while avoiding a display area, and an input system including the same.SOLUTION: A coordinate input system 1 includes: a coordinate input device having an operation pen 8 and a coordinate input module 3A; and a liquid crystal display module 2. In the operation pen 8, a pen tip (specifically, a light diffusion portion) of the operation pen 8 causes a part of light propagating through a light guide plate 10 of the coordinate input module 3A to be incident from a contact surface in contact with an upper surface of the light guide plate 10 and cause the incident light to be diffused and be incident on the light guide plate 10 again through the contact surface in contact with the upper surface of the light guide plate 10.

Description

  The present invention relates to an input device that performs coordinate detection of an input position, and an input system including the input device.

  There is known an input system in which a bar-shaped operation member (hereinafter referred to as a pen) such as a touch pen or a stylus pen is combined with a coordinate input device such as a tablet or a touch panel that accepts coordinate input by the pen. The pen is brought into contact with the coordinate input area of the coordinate input device, and the coordinate input device obtains the coordinates of the position where the pen is in contact (hereinafter referred to as touch). The obtained coordinates are, for example, for displaying an object such as a point image or a straight line image on a display screen such as a liquid crystal display separate from the coordinate input device, or a liquid crystal panel laminated integrally with the coordinate input device. Used for.

  FIG. 21 is a schematic configuration diagram showing a liquid crystal display device as an information input device disclosed in Patent Document 2. As shown in FIG. The liquid crystal display device shown in FIG. 21 includes an infrared (IR) light source 301b, a plurality of light receiving elements 210 that detect the re-entered light when the IR light output from the display surface 200A is re-entered, An optical panel 200 having a stylus, and a stylus pen 201. The stylus pen 201 is covered with a first material that has almost no loss of light because the surface of the pen tip portion 203 has a high transmittance, and the inside of the pen tip portion 203 covered with the first material has a resistance against IR light. A reflection portion 204 made of a second material having a transmittance lower than that of the first material and having a higher reflectivity for IR light than that of the first material is formed. When the stylus pen 201 is brought into contact with or close to the surface of the optical panel 200, IR light generated by the IR light source 301b of the optical panel 200 passes through the pen tip portion 203 and reaches the internal reflection portion 204. The light is reflected by the reflection unit 204 and returned to the outer surface of the optical panel 200 again. The reflected light that has reached the outer surface of the optical panel 200 is re-entered into the optical panel 200, received by the light receiving element 210, and subjected to processing for a predetermined purpose such as position detection and operation command detection.

JP 2010-26693 A (published February 4, 2010)

  In the configuration of Patent Document 1 described above, light is received by the light receiving element 210 without the pen tip portion 203 of the stylus pen 201 being in contact with the surface of the optical panel 200. For this reason, the light receiving element may detect light contrary to the intention of the stylus pen user, that is, it may cause a malfunction.

  Moreover, although the reflection part 204 provided in the inside of the pen point part 203 of patent document 1 has a reflective surface of a plane or a concave surface, the reflected light reflected in the reflective surface of such a shape is sent to a light guide plate. Hard to recombine. That is, most of the reflected light enters from the contact or proximity area (touch surface) of the stylus pen 201 and exits to the opposite surface (back surface). Therefore, the light receiving element can only be disposed on the touch surface of the stylus pen 201 on the touch surface or just on the back side of the proximity region, and the installation location of the light receiving element is limited. Further, since the contact or proximity region of the stylus pen 201 also serves as a display region as shown in Patent Document 2, the display quality is inevitably deteriorated due to the light receiving element disposed there.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an input device having a novel configuration in which a light receiving element can be set off from a display area without malfunctioning, and the input device. To provide an input system.

That is, in order to solve the above-described problem, the input device according to the present invention includes:
A light guide plate through which light propagates;
An operation member in contact with the upper surface of the light guide plate;
A plurality of light extraction portions for extracting a part of the light propagating through the light guide plate at a plurality of locations apart from each other in the light guide plate;
A light receiving means for receiving the light extracted by each of the light extraction units;
The traveling direction of the light extracted from the two light extraction portions separated from each other in the light guide plate is obtained from the light reception result of the light receiving means, and from the traveling direction and the separation distance of the two light extraction portions, Detecting means for detecting the position coordinates of the contact object in contact with the upper surface of the light guide plate,
The operation member has a tip portion provided with a contact surface that comes into contact with the upper surface of the light guide plate, and the tip portion transmits light that propagates through the light guide plate from the contact surface in contact with the upper surface of the light guide plate. Is incident on the light guide plate again from the contact surface that is in contact with the upper surface of the light guide plate by scattering the incident light,
The plurality of light extraction portions are characterized in that scattered light incident on the light guide plate is extracted from the contact surface in contact with the upper surface of the light guide plate to extract part of the propagation light propagating in the light guide plate.

  According to the above configuration, the distal end portion of the operation member causes a part of the light propagating through the light guide plate to be incident from the contact surface in contact with the upper surface of the light guide plate, and scatters the incident light to cause the upper surface of the light guide plate to The light is incident on the light guide plate again from the contact surface in contact with the light guide. That is, the operation member (for example, a structure such as a pen) causes light (scattered light) to enter the light guide plate again in a state where it is in contact with the upper surface of the light guide plate. For this reason, the malfunction does not occur as in the conventional configuration.

  Moreover, according to said structure, since the light which injects into a light guide plate again from the contact surface of the front-end | tip part of an operation member is scattered light, it recombines in a light guide plate. Therefore, since the recombined light can propagate through the inside of the light guide plate, it can be propagated to the end portion of the light guide plate, for example. Thereby, it is possible to arrange the light receiving means at the end of the light guide plate. In other words, unlike the conventional configuration, it is not necessary to dispose the light receiving means just behind the area where the stylus pen touches or is close to the stylus pen. Therefore, for example, even in the case of an input device having a touch function in the display area, the light receiving means can be disposed at a position removed from the display area, and display quality is not impaired.

Moreover, in addition to said structure, one form of the input device which concerns on this invention is
The tip portion is preferably provided with a light scattering portion provided with the contact surface for scattering the incident light and a light reflecting portion for reflecting the light.

  According to said structure, the light reflection part is provided, and the light quantity which the light scattered in the said light scattering part injects into a light-guide plate through a contact surface is not provided with a light reflection part Can be increased compared to Thereby, it is possible to detect the coordinates of the contact position more accurately.

Moreover, in addition to said structure, one form of the input device which concerns on this invention is
The light reflecting portion has a convex curved surface that is convex toward the light reflecting side,
The light scattering portion is preferably located between the convex curved surface and the contact surface.

  According to the above configuration, since the light scattering portion is provided between the convex curved surface and the contact surface, both the light before entering the convex curved surface and the reflected light reflected on the convex curved surface are scattered. be able to.

  As a result, the light incident on the light guide plate again from the contact surface at the tip of the operation member is sufficiently scattered, and the coupling efficiency to the light guide plate can be increased, so that a more accurate contact position. It is possible to detect the coordinates.

Moreover, in addition to said structure, one form of the input device which concerns on this invention is
It is preferable that the said front-end | tip part is comprised from the material which the area of the said contact surface spreads by the press at the time of the said contact surface contacting the upper surface of a light-guide plate.

  According to said structure, since the optical coupling efficiency from an operation member to a light-guide plate can be improved, position detection accuracy can be improved.

Moreover, in addition to said structure, one form of the input device which concerns on this invention is
The light scattering portion is a container-like structure that is convex toward the contact surface, and the container-like structure is made of a resin having light scattering properties,
The light reflecting portion is a spherical structure housed in the container-like structure, and is preferably made of metal.

  According to said structure, light scattering can be implement | achieved by the light-scattering part which is the said container-shaped structure, and light can be reflected with a spherical metal.

Moreover, in order to solve said subject, the input system which concerns on this invention
An input device having the above configuration;
An image display panel having a plurality of pixels,
The pixel of the image display panel is driven based on the position coordinates detected by the detection means.

  According to said structure, it can comprise so that the pixel corresponding to the said position coordinate in an image display panel can be driven and visually recognized.

  According to the present invention, it is possible to provide an input device having a novel configuration in which a light receiving element can be set off from a display area without malfunction and an input system including the input device.

It is a disassembled perspective view which shows the structure of one Embodiment of the coordinate input system in this invention. (A) is a top view which shows the structure of a coordinate input system, (b) is side sectional drawing which shows the structure of a coordinate input system. (A) is a side view which shows the structure of a coordinate input system, (b) is a principal part side view which expands and shows the structure of the edge part of a coordinate input system. FIG. 8 shows a configuration of a coordinate input system, and is a cross-sectional view taken along line AA in FIG. 7. It is a top view which shows the irradiation area | region to the light-guide plate in one LED. (A) And (b) is sectional drawing which shows the structure of the optical coupling member provided between the light-guide plate and LED. It is a perspective view which shows the optical path of scattered light when a finger touches a light-guide plate. It is sectional drawing which shows the structure of the operation pen with which the coordinate input system of FIG. 1 is equipped. It is a figure which shows the modification of an operation pen. It is a figure which shows the modification of the light reflection part of an operation pen. (A) is a top view which shows the detection principle of a coordinate input device, (b) is a wave form diagram which shows the optical signal of the image pick-up element in the imaging unit of a coordinate input device. (A) is a top view which shows the contact position when a finger | toe contacts the various places in the surface of a light-guide plate, (b) is the pixel number which appears in the detection image of an image pick-up element corresponding to the contact position of this finger | toe It is a wave form diagram which shows the relationship with signal strength. (A) is a perspective view which shows the imaging condition in the imaging unit in the said coordinate input device, (b) is a top view which shows the image in the image pick-up element of the said imaging unit. It is a top view which shows the lighting control method of the light source unit in the said coordinate input device. FIG. 10 is a plan view showing another embodiment of the coordinate input device according to the present invention and showing a state where a finger is brought into contact with a proximity position of an imaging unit. It is a top view which shows the malfunction when a finger | toe is simultaneously contacted at two places when two imaging units are provided in one 1st edge part of the light-guide plate. It is a perspective view which shows the structure of the coordinate input device in said other embodiment. It is a top view which shows the lighting control method of the light source unit of the coordinate input device in said other embodiment. In the coordinate input device in the other embodiment, it is a plan view showing a detection method when a finger is brought into contact with the proximity position of the imaging unit. It is a top view which shows the detection method when the several finger | toe is contacted with the light-guide plate in the coordinate input device in the said other embodiment. It is a figure of a conventional structure.

Embodiment 1
A coordinate input device that is an embodiment of the input device according to the present invention and a coordinate input system that is an embodiment of the input system according to the present invention will be described with reference to FIGS. It is.

(1) Configuration of Coordinate Input System A coordinate input system (input system) according to the present embodiment includes a coordinate input device (input device) including an operation pen (operation member) and a coordinate input module, and a liquid crystal display module (image display module). ) And comprising.

  A part of the configuration of the coordinate input system according to the present embodiment will be described with reference to FIGS. FIG. 1 is an exploded perspective view showing a configuration of a part of the coordinate input system. Moreover, Fig.2 (a) is a top view which shows the structure of a part of coordinate input system, FIG.2 (b) is the side sectional drawing. 1 is the front side (touch side) of the coordinate input system (coordinate input module). 1 is the long side direction of the coordinate input module, and the Y direction in FIG. 1 is the short side direction of the coordinate input module.

(1-1) Liquid Crystal Display Module The liquid crystal display module 2 configured in the coordinate input system 1 of the present embodiment is an image display module disposed on the opposite side to the front side of the coordinate input module as shown in FIG. is there.

  As shown in FIG. 2, the liquid crystal display module 2 has a liquid crystal layer sandwiched between a pair of substrates (not shown), and each substrate has various electrodes for changing the orientation of liquid crystal molecules of the liquid crystal layer by applying a voltage. A liquid crystal display panel 2a is provided. The liquid crystal display panel 2a performs desired display by adjusting the amount of light transmitted through the liquid crystal layer of each pixel by changing the alignment of liquid crystal molecules by applying a voltage between the electrodes. The liquid crystal display panel 2a is supported by the chassis 2b, and a protective glass 2c is provided on the front surface of the liquid crystal display panel 2a. The liquid crystal display module 2 is not limited to the above-described configuration, and a conventionally known liquid crystal display module can be used.

  The user of the coordinate input system 1 of the present embodiment touches the operation pen on the light guide plate 10 of the coordinate input module 3A provided on the front side of the liquid crystal display panel 2a while looking at the screen displayed on the liquid crystal display panel 2a. Let

(1-2) Coordinate Input Module In the coordinate input system 1 of the present embodiment, the operation pen is brought into contact with the light guide plate 10 of the coordinate input module 3A provided on the front side of the liquid crystal display panel 2a, and the coordinates of the contact position are obtained. Is specified by the coordinate input module 3A so that desired data can be input. Therefore, the configuration of the coordinate input module 3A will be described with reference to FIGS. FIG. 4 shows a partial configuration of the coordinate input system 1, and is a cross-sectional view taken along line AA in FIG. FIG. 3A is a side view showing a part of the configuration of the coordinate input system 1, and FIG. 3B is an enlarged side view showing the configuration of the edge of the part of the configuration of the coordinate input system 1. FIG. FIG. 5 is a plan view showing an irradiation area to the light guide plate 10 in one LED. FIG. 6 is a cross-sectional view illustrating a configuration of an optical coupling member provided between the light guide plate 10 and the LED 4a. FIG. 7 is a perspective view showing an optical path of scattered light when the operation pen 8 is touched on the light guide plate 10.

  As shown in FIG. 1 and FIG. 2A, the coordinate input module 3A includes a rectangular light guide plate 10 and imaging units 20 and 30 as light receiving means respectively disposed at corner portions of the rectangular light guide plate 10. , 40, 50 and light source units 4A, 4B as light sources provided on the back sides of both sides in the long side direction of the light guide plate 10, and optical coupling for coupling light from the light source units 4A, 4B to the light guide plate 10 The member 5 and the detection part 6 (detection means) (FIG. 4) are provided. Further, as shown in FIG. 2B, light absorbing members 7 are provided on the front side and the back side where the light source units 4 </ b> A and 4 </ b> B are disposed at the edge of the light guide plate 10.

  The light guide plate 10 is made of a single rectangular flat plate made of a translucent material, and is disposed on the display surface side of the liquid crystal display panel 2 a in the liquid crystal display module 2. The light guide plate 10 does not have to be a complete rectangle, and as will be described later, through holes 11 are formed in the corners, corners are notched, or the corners are curved. It may be a substantially quadrangular shape.

  For example, as shown in FIG. 2, the size of the light guide plate 10 is configured such that the periphery of the four sides is larger than the liquid crystal display panel 2a. Thereby, the imaging units 20, 30, 40, 50 can be arranged on the back side of the light guide plate 10. As a result, an increase in size in the direction extending along the touch surface of the coordinate input module 3A is suppressed, contributing to the realization of a compact size of the coordinate input module 3A. The size of the rectangular light guide plate 10 may be, for example, a diagonal of 60 inches, but is not limited thereto. For example, it may be 60 inches, 70 inches, 80 inches,... Or larger, or 60 inches or less.

  The thickness of the light guide plate 10 is mainly 1 to 3 mm. However, it may be thicker than this. In the present embodiment, the thickness is 3 mm, for example. As a material of the light guide plate 10, for example, acrylic is used, and polycarbonate or glass may be used.

  Further, as shown in FIG. 3, through-holes 11 (as concave conical surface-shaped optical path conversion portions) are formed at four corners of the light guide plate 10 where the imaging units 20, 30, 40, 50 are disposed. Each light extraction portion is formed. In addition, in this embodiment, although the through-hole 11 is comprised by the conical surface shape, this invention is not limited to this, You may be comprised by the hyperboloid shape or the polygonal surface shape. Further, the central portion of the through hole 11 does not necessarily have to penetrate. The slope may be formed up to the middle of the thickness of the light guide plate 10. In this case, the imaging units 20, 30, 40, 50 are sealed, so that no foreign matter is mixed into the imaging units 20, 30, 40, 50.

  As shown in FIG. 4, the angle γ formed between the conical wall surface 11a (light extraction portion) of the through hole 11 and the back surface of the light guide plate 10 is 45 degrees or less, and for example, 30 degrees or 24 degrees is selected. A mirror coating is applied to the conical surface wall surface 11 a in the through hole 11. As a result, as shown in FIG. 4, the optical path of the light propagating through the inside of the light guide plate 10 and reaching the through hole 11 is changed by the through hole 11 below the light guide plate 10, that is, toward the back surface of the light guide plate 10. Let Even if the wall surface 11 a is not mirror-coated, the optical path can be changed below the light guide plate 10 by the conical surface of the through hole 11. In the present embodiment, since the optical path conversion unit is provided as the through hole 11 at the corner of the light guide plate 10, the optical path conversion unit is prevented from protruding from the light guide plate 10.

  Next, the imaging units 20, 30, 40, 50 are arranged immediately below the conical surface through holes 11 at the four corners of the light guide plate 10. Thus, the imaging units 20, 30, 40, 50 have a structure that does not protrude above the surface of the light guide plate 10.

  In the coordinate input module 3 </ b> A, the imaging units 20, 30, 40, 50 are provided at four corners of the light guide plate 10 that are separated from each other. However, in the present invention, the installation locations of the imaging units 20, 30, 40, and 50 are not necessarily limited to the corners. For example, imaging units 20 and 30 are provided in at least two locations on one first edge along the longitudinal direction of the light guide plate 10, and the other of the other edges of the light guide plate 10 facing the first edge. It can be assumed that the imaging units 40 and 50 are also provided in at least two places on the second edge. The reason for this is that, as will be described later, in the coordinate input module 3A, the imaging units 20 and 30 at one first edge of the light guide plate 10 and the imaging units 40 and 30 at the other second edge of the light guide plate 10 50 is used alternately. In other words, since triangulation requires at least two light receiving means, two or more imaging units 20 and 30 and imaging units 40 and 50 are provided on each of the first edge and the second edge. It is necessary to provide it.

  As shown in FIG. 4, the imaging units 20 and 40 include lenses 21 and 41, optical filters 22 and 42, and imaging elements 23 and 43. Similarly, the imaging unit 30 also includes a lens 31, an optical filter 32, and an imaging element 33, as shown in FIG. Furthermore, although the imaging unit 50 is not shown, it has the same configuration.

  The optical filters 22 and 42 shown in FIG. 4 play a role of transmitting light in the wavelength band emitted from the operation pen 8 and blocking light in other wavelength bands. The optical filters 22, 42 and the like block sunlight and stray light such as backlight light for liquid crystal display panels, thereby increasing the SN ratio. However, in the detection of scattered light due to the touch of the operation pen 8, it is sufficient to take a difference from the background video signal, and therefore an optical filter is not necessarily required.

  The imaging elements 23, 33, 43, etc. are made up of, for example, a two-dimensional image sensor. However, the image sensor is not necessarily limited to two dimensions, and may be a one-dimensional image sensor. Alternatively, a CMOS (Complementary Metal Oxide Semiconductor) camera may be used.

  The light receiving surfaces of the imaging elements 23, 33, 43 and the like are arranged so as to be parallel to the surface of the light guide plate 10.

  The imaging units 20, 30, 40, 50 are connected to the light guide plate 10, and have a structure in which light that does not propagate through the light guide plate 10 is not coupled to the imaging elements 23, 33, 43, and the like.

  Next, the light source units 4A and 4B provided at the edges of both sides in the longitudinal direction of the light guide plate 10 are each provided with a plurality of LEDs 4a... Arranged in series, as shown in FIG. Each LED 4a emits light such as infrared light. However, it is not necessarily limited to infrared light, and may be visible light or ultraviolet light. Further, it is not always necessary to use the LED 4a, and an LD (laser diode) or the like can also be used.

  Here, the light source units 4 </ b> A and 4 </ b> B are provided at the edges of both sides in the longitudinal direction of the light guide plate 10. That is, in the coordinate input module 3A, the imaging units 20 and 30 and the light source unit 4A are provided on one first edge portion along the longitudinal direction of the light guide plate 10, and the imaging units 40 and 50 and the light source unit 4B. Are respectively provided on the other second edge opposite to the first edge. In this case, since the light source units 4A and 4B and the imaging units 20, 30, 40, and 50 are all provided on the back side of the light guide plate 10, the light source units 4A and 4B are the imaging units 20 and 30 or the imaging unit. 40 and 50 are provided between the imaging unit 20 and the imaging unit 30 or between the imaging unit 40 and the imaging unit 50 so that they do not overlap. Further, as shown in FIG. 4, the light source unit 4 </ b> A is provided at the outer peripheral end of the light guide plate 10 as compared with the imaging unit 20, and the light source unit 4 </ b> B is guided as compared with the imaging unit 40. It is provided at the outer peripheral end of the optical plate 10. Therefore, in the imaging units 20, 30, 40, 50, direct light from the light source units 4 </ b> A, 4 </ b> B does not enter the signal detection effective area of the imaging units 20, 30, 40, 50. Further, the light guide plate 10 is not cut or attached to the portion outside the signal detection effective area, or the light absorbing member 7 is attached, or the through hole 11 that is an optical path changing portion is not formed outside the signal detection effective area. This is preferable because unnecessary light can be reliably blocked.

  As described above, the light source units 4 </ b> A and 4 </ b> B are preferably provided on the first edge and the second edge on both sides of the light guide plate 10 along the long side direction. The reason for this is that, as shown in FIG. 5, the LED 4 a is provided on both sides along the long side direction of the light guide plate 10 at the edges of both sides along the short side direction of the light guide plate 10. This is because the light reaching distance of the LED 4a within the light guide plate 10 is shorter. That is, this increases the amount of light from the light source units 4A and 4B and also reduces the distance from the operation pen 8 in contact with the light guide plate 10 to the imaging units 20, 30, 40, and 50. This is because the detection intensity of the imaging units 20, 30, 40, and 50 in the scattered light from the touched operation pen 8 increases.

  Here, when the scattered light from the operation pen 8 is detected by the imaging devices 23, 33, 43, etc., it is necessary to increase the output of the scattered light from the imaging devices 23, 33, 43, etc. as much as possible. For this purpose, it is preferable that the amount of propagating light from the LED 4a inside the light guide plate 10 is larger. Therefore, as shown in FIG. 5, the radiation angle δ of one LED 4a is made small. This is because when the radiation angle δ of the LED 4a is large, the light amount density of the irradiation region in one LED 4a decreases.

  Here, in the present embodiment, the light source units 4 </ b> A and 4 </ b> B are disposed on the back side of the light guide plate 10. In this case, if the light of each LED 4a of the light source units 4A and 4B is vertically incident on the light guide plate 10, the incident light does not guide the inside of the light guide plate 10 and remains on the front surface of the light guide plate 10 as it is. Go through. Therefore, in this embodiment, as shown in FIG. 1, an optical coupling member 5 is provided between the light guide plate 10 and the light source units 4A and 4B, and as shown in FIG. 6, the LEDs 4a of the light source units 4A and 4B. The light from... Is incident on the light guide plate 10 through the optical coupling member 5 at an angle.

  Specifically, as shown in FIG. 6A, the optical coupling member 5 may be composed of, for example, a triangular prism 5a. The prism 5a can be bonded to the light guide plate 10 using, for example, a double-sided tape 5b or an adhesive. Then, by adhering the LED 4a to the inclined surface of the prism 5a, light can be incident on the light guide plate 10 obliquely as shown in FIG.

  As shown in FIG. 6B, a bullet-type LED 4a can be used as the LED 4a. In this case, as the optical coupling member 5, a transparent block 5 c that can obliquely fix the bullet-type LED 4 a with respect to the light guide plate 10 can be used. This also allows light to enter the light guide plate 10 at an angle.

  The coordinate input module 3A is further provided with a detection unit 6 shown in FIGS. The detection unit 6 detects the output of the imaging device based on light scattering by the operation pen 8 and obtains the coordinates of the contact position of the operation pen 8 on the surface of the light guide plate 10. Specifically, it consists of a CPU.

  A light absorbing member 7 is provided on the first edge and the second edge of the light guide plate 10 so as not to overlap the light source units 4A, 4B and the imaging units 20, 30, 40, 50. The light absorbing member 7 has a high light shielding film made of, for example, a black polyester film or the like attached to the light guide plate 10 so that the reflected light at the end of the light guide plate 10 does not return to the opposite end. In addition, the reflected light is absorbed.

(1-3) Operation Pen FIG. 8 is a cross-sectional view showing the configuration of the operation pen 8 provided in the coordinate input system 1 of the present embodiment. For convenience of explanation, the light guide plate 10 is also shown in FIG.

  The operation pen 8 has a rod-like shape, and is a portion held by the user of the operation pen and a pen tip portion 81 (tip portion) close to the side in contact with the light guide plate 10 along the longitudinal direction thereof. And a handle portion 82.

  Here, one of the features of the present invention is the configuration of the pen tip portion 81 of the operation pen 8. Specifically, the pen tip 81 has a light scattering portion 83 having a contact surface 85 that contacts the light guide plate 10, and the light scattering portion 83 is guided from the contact surface 85 that contacts the light guide plate 10. A part of light propagating through the light plate 10 (that is, light emitted from the light source unit 4A and guided through the light guide plate 10) is incident, and the incident light is scattered. The scattered light enters the light guide plate 10 again from the contact surface 85 in contact with the light guide plate 10, guides the light guide plate 10, and is received by the imaging unit 20.

  The light scattering portion 83 can be made of a resin having a light scattering property, but the material constituting the light scattering portion 83 is not limited to this. The light scattering portion 83 is preferably one that has improved scattering properties, for example, by mixing fine particles or forming a fine structure.

  The light scattering portion 83 is preferably made of a flexible material that deforms within a range in which the function of the light scattering portion 83 is maintained by the impact of the user bringing the operation pen 8 into contact with the light guide plate 10. Due to the deformation, the area of the contact surface 85 is widened, the propagation conditions of the light emitted from the light source unit and propagating through the light guide plate 10 are broken, and the propagating light is easily incident on the light scattering portion 83, and the scattered light Can be effectively incident and coupled to the inside of the light guide plate 10. A specific example of the material constituting the light scattering portion 83 is silicon. Alternatively, a foaming agent of resin such as acrylic may be used. The acrylic foam agent is also similar to the above, and has a light scattering property because it has a fine structure.

  In the present embodiment, the tip of the light scattering portion 83 has a curved surface in a state where the light scattering portion 83 is not in contact with the light guide plate 10, but is not limited to this structure.

  Further, the light scattering portion 83 may be coated on the surface in order to reduce the frictional force when the pen tip portion 81 slides on the upper surface of the light guide plate 10. The coating material is not particularly limited as long as it can realize friction reduction. For example, a fluororesin can be used. The light scattering portion 83 itself can be made of a material having wear resistance.

  Here, the light scattering portion 83 is configured to be removable from the light reflecting portion 84 and the handle portion 82. As a result, when the light scattering portion 83 is damaged, it can be replaced with another light scattering portion 83 that is not damaged. The light scattering portion 83 is provided with a concave portion on the side connected to the light reflecting portion 84, and the concave portion may be configured to fit with a convex portion formed at the tip of the light reflecting portion 84. In this case, the front end surface of the convex portion of the light reflecting portion 84 is a flat surface, and the light scattering portion 83 does not come off the light reflecting portion 84 while the operation pen 8 is slid on the upper surface of the light guide plate 10. It is like that.

  As shown in FIG. 8, the pen tip portion 81 is further provided with a light reflecting portion 84 having a light reflecting surface 86 disposed inside the light scattering portion 83. The light that has been scattered by the light scattering portion 83 is reflected by the light reflecting surface 86, travels toward the contact surface 85, and is emitted from the contact surface 85 to the light guide plate 10. In FIG. 8, the light reflecting surface 86 is formed in a flat shape, but the present invention is not limited to this, and a convex curved surface that is convex toward the contact surface 85 as shown in FIG. It may be a light reflecting surface 86 ′ or may have another surface shape.

  The light reflecting portion 84 can be configured integrally with the handle portion 82. For example, the light reflecting portion 84 itself does not have light reflectivity, and only the portion disposed inside the light scattering portion 83 in the light reflecting portion 84, that is, the portion including the light reflecting surface 86 is subjected to light reflecting processing. It is good. However, you may comprise the light reflection part 84 whole from a light reflective material. The light reflecting portion 84 or the light reflecting surface 86 can be made of aluminum, for example. Other than aluminum, gold or silver may be used. It is preferable to select a material having a high reflectance with respect to the wavelength of light propagating through the light guide plate.

  Note that the configuration shown in FIG. 10 can be adopted as a modification of the light reflecting portion 84. FIG. 10 shows a tip portion of an operation pen having a pen tip portion 81 ′ in which a spherical light reflecting portion 84 ′ is accommodated in a light scattering portion 83 ′ that is a bowl-shaped container. The surface of the spherical light reflecting portion 84 ′ constitutes a light reflecting surface 86 ′ having a convex curved surface, and the light scattering portion 83 ′ is disposed so as to be detachable from the handle portion 82.

(2) Coordinate detection principle The coordinate detection principle when the operation pen 8 contacts the light guide plate 10 in the coordinate input module 3A will be described with reference to FIGS. 4, 7, 11, and 12. FIG. FIG. 11A is a plan view showing the detection principle of the coordinate input module 3A, and FIG. 11B is a waveform diagram showing an optical signal of the image sensor in the imaging unit of the coordinate input module 3A. FIG. 12A is a plan view showing a contact position when the operation pen comes into contact with various places on the surface of the light guide plate, and FIG. 12B shows a detection image of the image sensor corresponding to the contact position of the operation pen. It is a wave form diagram which shows the relationship between the pixel number which appears in, and signal strength.

  First, in the coordinate input module 3A, as shown in FIG. 4, light is incident on the light guide plate 10 obliquely from the plurality of LEDs 4a ... of the light source unit 4A provided along at least one edge of the light guide plate 10. The

  As shown in FIG. 4, the light incident on the light guide plate 10 is guided as propagating light to the entire inner surface of the light guide plate 10. That is, light repeats total reflection inside the light guide plate 10 due to the difference between the refractive index of the light guide plate 10 and the refractive index of air. The totally reflected light is emitted from the end face of the light guide plate 10. The light that is reflected by the end face of the light guide plate 10 and returned is absorbed by the light absorbing members 7 on the front and back surfaces of the light guide plate 10 and does not return to the imaging units 20 and 30 side.

Here, as shown in FIG. 4, when the operation pen 8 touches or touches the surface of the light guide plate 10, the total reflection condition inside the light guide plate 10 is broken, and the operation pen 8 causes the inside of the light guide plate 10 having a refractive index n. Part of the infrared light that guides the light is scattered. Of this scattered light, the propagation angle θ _P in the light guide plate 10 is
sin (90 ° −θ _P )> 1 / n
The light beam satisfying the conditions shown in (2) repeats reflection on the front and back surfaces of the light guide plate 10 and travels in the light guide plate 10.

  Here, as shown in FIG. 7, infrared light that is scattered light of the operation pen 8 is diffused radially with respect to the two-dimensional plane of the light guide plate 10 and propagates in the light guide plate 10. Then, a part of the propagation light 13a, 14a of the light flux is guided to the wall surface 11a of the conical surface through-hole 11, and the reflected light of the wall surface 11a is received by the imaging units 20, 30. Specifically, the reflected light of the wall surface 11a of the through-hole 11 is collected by the lenses 21 and 31 in the imaging units 20 and 30, and then passes through the optical filters 22 and 32, and finally the imaging element 23 and 33 receives light. As a result, as shown in FIG. 11B, a light emission peak appears at the pixel number in each of the image sensors 23 and 33. Therefore, the detection unit 6 converts the pixel number in each image obtained from each of the image sensors 23 and 33 into an angle, and thereby, as shown in FIG. 11A, the light guide plate 10 at the place where the operation pen 8 is in contact. The angles α and β, which are the viewing angles from the imaging units 20 and 30 in the two-dimensional plane, are obtained.

For example, as shown in FIG. 12A, when the operation pen 8 is brought into contact with the points P ₁ to P ₉ on the light guide plate 10, the image pickup device 43 of the image pickup unit 40 has the image pickup element 43 shown in FIG. As shown, each peak appears at the position of the pixel number corresponding to the points P ₁ to P ₉ . By converting this pixel number into an angle, the angles of the points P ₁ to P ₉ can be obtained. In FIG. 12B, it can be roughly seen that pixel number 100≈angle 80 degrees, pixel number 200≈angle 60 degrees, pixel number 300≈angle 40 degrees, pixel number 400≈angle 20 degrees.

(3) Calculation Method of Two-Dimensional Coordinate Position Next, a calculation method of the two-dimensional coordinate position of the light guide plate 10 at the place where the operation pen 8 is in contact will be described based on FIG. This processing is performed by the detection unit 6. Here, FIG. 13A is a perspective view illustrating an imaging state of the imaging unit 20 in the coordinate input module 3 </ b> A, and FIG. 13B is a plan view illustrating an image of the imaging unit 20 of the imaging unit 20. . In FIG. 13, only the imaging unit 20 will be described, but the same processing is performed in the imaging unit 30.

  As shown in FIGS. 4 and 13A, the light incident on the imaging unit 20 forms a linear image 25 on the imaging element 23 through the lens 21. The position of the linear image 25 changes depending on the position of the operation pen 8, and the angle α formed between the propagation light 13 a and one side of the light guide plate 10 is obtained by analyzing the acquired image of the image sensor 23. Similarly, a linear image 25 is formed on the image pickup device 33 through the lens 31 by the light incident on the image pickup unit 30. Then, by analyzing the acquired image of the image sensor 33, an angle β formed by the propagation light 14a and one side of the light guide plate 10 is obtained. Based on the angles α and β, the position coordinates of the point touched by the operation pen 8 can be obtained using the triangulation method.

Specifically, in FIG. 13 (a), the case where the operation pen 8 is in the position of point P _1, as shown in FIG. 13 (b), the linear image 25 is formed. Further, when the operation pen 8 is moved to the position of the point P _2, the image 27 of the line shape is formed.

  When the operation pen 8 is not in contact with the light guide plate 10 in the state of irradiating light from the light source unit 4A, no change occurs in the acquired images of the image sensors 23 and 33. On the other hand, when the operation pen 8 comes into contact with the light guide plate 10 and scattered light is generated, the propagation lights 13a and 14a in a part of the light flux are guided to the imaging elements 23 and 33, and the imaging surfaces of the imaging elements 23 and 33 are detected. A linear image is formed, and a linear image 25 appears on the acquired image.

The position of the linear image 25 shown in FIG. 13B changes depending on the position of the contact point on the operation pen 8, and when the position of the contact point of the operation pen 8 is changed, the linear image 25 becomes a line. It changes like the image 27. The trajectories of the linear images 25 and 27 have a fan shape 26 indicated by a one-dot chain line. The inclination angle α ₁ ′ of the line segment connecting the fan-shaped center and the line-shaped image 25 (with the center of the arc as the rotation center) is the above-described value of the line segment connecting the operation pen 8 and the image sensor 23 and the light guide plate 10. The angle is the same as the angle α ₁ formed by one side. Therefore, the inclination angle α ₁ ′ is obtained from the acquired image of the image sensor, and the angle α ₁ is obtained from the inclination angle α ₁ ′. Similarly, when the operation pen 8 is moved to the position of the point P _2, a linear image 27 is formed, and the angle α ₂ is obtained by obtaining the inclination angle α ₂ ′ of the linear image 27.

  Similarly, for the image sensor 33, the position of the light emitting point is specified from the analysis of the acquired image, and an angle β formed by a line segment connecting the operation pen 8 and the image sensor 33 and the certain side of the light guide plate 10 is obtained.

The distance between the image sensor 23 and the image sensor 33 is L, the angle of the bright spot obtained by reading the image from the image sensor 23 is α, and the angle of the bright spot obtained by reading the acquired image from the image sensor 23 is When β is defined, the coordinates (X, Y) of the bright spot are the following relational expressions (1) and (2).
Y = tan α · X (1)
Y = tan β · (L−X) ... Relational expression (2)
Satisfied. Solving this, the coordinates (X, Y) of the bright spot are
X = tan β · L / (tan α + tan β) Equation (3)
Y = (tan α · tan β) · L / (tan α + tan β) (4)
The coordinates X and Y of the point where the operation pen 8 is in contact can be obtained from the angles α and β obtained as described above and the interval L that can be obtained in advance. Among these, the space | interval L is a space | interval between the image pick-up element 23 and the image pick-up element 33, and is a fixed value. By obtaining the angles α and β, the coordinates X and Y in the coordinate input module 3A can be obtained.

  The distance L between the image sensor 23 and the image sensor 33 is a distance between the optical axis center of the lens 21 and the optical axis center of the lens 31.

  Further, based on the position coordinate of the operation pen 8 obtained by the above method, the pixel located at the position corresponding to the position coordinate of the liquid crystal display panel 2a is driven, and the user determines the touch position of the operation pen 8. It is possible to make it visible. For this purpose, a control unit (not shown) that controls the driving of the liquid crystal display panel 2a may acquire information on the position coordinates obtained by the detection unit 6 and drive the liquid crystal display panel 2a based on the information.

(4) Coordinate detection method of contact position in a plurality of operation pens In the coordinate input module 3A of the present embodiment, even when a plurality of operation pens 8 are in contact with the light guide plate 10, each operation pen 8 is not affected. The coordinate position of can be detected. A configuration for this will be described with reference to FIG. FIG. 14 is an explanatory diagram showing a configuration for enabling detection even when the plurality of operation pens 8 touch the light guide plate 10 in the coordinate input module 3A of the present embodiment.

  As described above, the coordinate input module 3 </ b> A includes the plate-shaped light guide plate 10, the light source units 4 </ b> A and 4 </ b> B that allow light to enter the light guide plate 10, at least two imaging units 20, 30, 40, and 50, Based on the output of the imaging units 20, 30, 40, 50 that detect the light scattering by the operation pen 8 when the object to be detected such as the operation pen 8 comes into contact with the surface of the operation pen 8, And a detection unit 6 that detects the coordinates of the position of contact with the surface.

  In such a coordinate input module 3 </ b> A, the light reception peak of the scattered light due to the presence of the detection object such as the operation pen 8 is detected in a state where the light reception change amount of the imaging units 20, 30, 40, 50 is maintained at 0.

  In the coordinate input module 3A of the present embodiment, the imaging units 20 and 30 and the light source unit 4A are provided at the first edge along the longitudinal direction of the light guide plate 10, and the imaging units 40 and 50 and the light source unit 4B are longitudinal. And a second edge facing the first edge along the direction.

  By the way, when it is set as such a structure, when the light source unit 4A of the 1st edge part and the light source unit 4B of the 2nd edge part facing this 1st edge part are lighted simultaneously, an imaging unit Since the light from the light source units 4A and 4B facing each other is incident on the 20, 30 or the imaging units 40 and 50, the scattered light due to the contact of the operation pen 8 cannot be detected. Therefore, in the present embodiment, as shown in FIG. 14, the light source unit 4A at the first edge and the light source unit 4B at the second edge are alternately turned on. That is, the light source unit 4B is turned off while the light source unit 4A is turned on, and the light source unit 4A is turned off while the light source unit 4B is turned on. The blinking speed is alternately turned on at 60 Hz, for example. However, the present invention is not necessarily limited to this, and the blinking speed can be set to 240 Hz, for example, and can be slower than 60 Hz.

  And in the period when the light source unit 4B of the 1st edge in the light-guide plate 10 is lighting, the imaging unit 20 and 30 provided in this 1st edge to the surface of the light-guide plate 10 in the operation pen 8 The coordinates of the contact position are detected. On the other hand, during the period when the light source unit 4B at the second edge of the light guide plate 10 is lit, the imaging units 40 and 50 provided at the second edge are used to access the surface of the light guide plate 10 in the operation pen 8. The coordinates of the contact position are detected.

  Thus, the light from the light source unit 4B facing the imaging units 20 and 30 is prevented from entering, and the light from the light source unit 4A is prevented from entering the imaging units 40 and 50. For this reason, the scattered light by the contact of the operation pen 8 can be detected.

  As a result, for example, when the operation pen 8A as the first object to be detected and the operation pen 8B as the second object to be detected are simultaneously brought into contact with the light guide plate 10, the imaging units 20, 30, 40, and 50 Separation can be detected using the detection signal. Strictly speaking, since the signal detection of the imaging units 40 and 50 at the second edge which is the upper side and the signal detection of the imaging units 20 and 30 at the first edge which is the lower side are alternated, they are not simultaneous. However, by shortening the blinking cycle or applying signal processing that interpolates movement from the preceding and following data, it is possible to handle the same as in the case of simultaneous detection. Further, if the interpolation data is used only for removing the erroneous recognition point, it is possible to suppress the deviation from the actual contact point.

  For example, the imaging units 20 and 30 detect both the operation pen 8A that has contacted first and the operation pen 8A that has contacted later. However, by removing the data of the operation pen 8 detected by the previous lighting of the light source unit 4A, the operation pen 8A due to the subsequent lighting of the light source unit 4A can be detected. Therefore, the coordinates of the contact position of each operation pen 8 can be obtained even when three or more operation pens 8 contact the light guide plate 10.

  Further, as will be described in the second embodiment described later, it is possible to simultaneously detect three or more operation pens 8 by increasing the number of light receiving means.

(5) Effects of this Embodiment As described above, the coordinate input device according to this embodiment includes the coordinate input module 3A and the operation pen 8, and includes pen tip portions 81 and 81 ′ (specifically, the operation pen 8). The light scattering portions 83 and 83 ′) make a part of the light propagating through the light guide plate 10 incident from the contact surface 85 in contact with the upper surface of the light guide plate 10 and scatter the incident light to scatter the light guide plate 10. The light is incident on the light guide plate 10 again from the contact surface 85 in contact with the upper surface of the light guide plate. That is, the operation pen 8 makes light (scattered light) incident on the light guide plate again while in contact with the upper surface of the light guide plate 10. For this reason, the malfunction does not occur as in the conventional configuration.

  Further, since light incident on the light guide plate 10 again from the contact surface 85 of the pen tip portions 81 and 81 ′ (specifically, the light scattering portions 83 and 83 ′) of the operation pen 8 is scattered light, Since it can recombine and can propagate the inside of a light-guide plate, it can propagate to the through-hole 11 which is the light extraction part provided in the edge part of the light-guide plate 10, for example. Thereby, the light receiving means (imaging unit) can be disposed at the end of the light guide plate 10. In other words, unlike the conventional configuration, it is not necessary to dispose the light receiving means just behind the area where the stylus pen touches or is close to the stylus pen. Therefore, for example, even in the case of an input device having a touch function in the display area, the light receiving means can be disposed at a position removed from the display area, and display quality is not impaired.

  Further, since the operation pen 8 is provided with the light reflecting portions 84 and 84 ′, the incident light amount that the light scattered by the light scattering portions 83 and 83 ′ enters the light guide plate 10 through the contact surface 85 can be reduced. , The light reflecting portions 84 and 84 ′ (light reflecting surfaces 86 and 86 ′) can be increased compared to the configuration in which the light reflecting portions 84 and 84 ′ (light reflecting surfaces 86 and 86 ′) are not provided. For example, in a configuration in which the bowl-shaped light scattering portion 83 ′ is made of silicon rubber, and a spherical metal is accommodated therein and the metal surface is the light reflecting surface 86 ′, the bowl-shaped light made of silicon rubber is used. Compared with an operation pen having a comparative configuration in which a sphere of transparent resin is accommodated in the scattering portion, the intensity (gradation) of the signal acquired by the light receiving element can be increased to 1.2 times.

  Thus, by providing the light reflecting portions 84 and 84 '(light reflecting surfaces 86 and 86') and increasing the amount of light that is radiated and coupled to the light guide plate 10, that is, the coupling efficiency can be increased, the contact position It is possible to perform the coordinate detection of more accurately.

  The coordinate input system 1 of the present embodiment is a coordinate input system including the coordinate input module 3A of the present embodiment, and includes a liquid crystal display module 2.

  According to this configuration, the coordinate input module 3 </ b> A can be functioned as a touch panel that is input by a detected object such as the operation pen 8 while viewing the image of the liquid crystal display module 2. Therefore, in the optical coordinate input module 3A that uses the light guide plate 10, even when applied to a large touch panel, the coordinate input module 3A that can detect the coordinate position of the detection object such as the operation pen 8 is provided. A system 1 can be provided.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIGS. The configurations other than those described in the present embodiment are the same as those in the first embodiment. For convenience of explanation, members having the same functions as those shown in the drawings of Embodiment 1 are given the same reference numerals, and explanation thereof is omitted.

  In the coordinate input module 3A of the first embodiment, the imaging units 20 and 30 and the light source unit 4A are provided on the first edge along the long side direction of the light guide plate 10, and the imaging units 40 and 50 and the light source unit 4B are , And provided on the second edge facing the first edge along the long side direction.

  On the other hand, in the coordinate input module 3B provided in the coordinate input system of the present embodiment, three or more light receiving means are provided on the first edge portion along the long side direction of the light guide plate 10. In addition, a difference is that three or more light receiving means are also provided on the second edge portion of the light guide plate 10 facing the first edge portion along the long side direction.

  The configuration of the coordinate input module 3B will be described with reference to FIGS. FIG. 15 is a plan view illustrating a state in which the operation pen is in contact with the proximity position of the imaging unit in the coordinate input module 3A of the first embodiment. FIG. 16 is a plan view showing a problem when the operation pen is simultaneously touched at two places in the coordinate input module 3A of the first embodiment. FIG. 17 is a perspective view showing the configuration of the coordinate input module 3B in the present embodiment. FIG. 18 is a plan view showing a lighting control method for the light source units 4A and 4B of the coordinate input module 3B. FIG. 19 is a plan view illustrating a detection method when the operation pen is brought into contact with the proximity position of the imaging unit in the coordinate input module 3B. FIG. 20 is a plan view illustrating a detection method when a plurality of operation pens are in contact with the light guide plate in the coordinate input module 3B.

That is, when the two imaging units 20 and 30 are provided as light receiving means at the first edge along the long side direction of the light guide plate 10, detection may be hindered as follows. . For example, as shown in FIG. 15, in the light guide plate 10, it is possible to easily detect the coordinate position of the contact position P ₁ of the operation pen 8 away from the imaging units 20 and 30. However, as shown in FIG. 15, the light guide plate 10, for the coordinate contact position P ₂ of the operation pen 8 in proximity to the imaging units 20 and 30, a small angle to the viewing direction from the imaging units 20 and 30 Therefore, the angle change with respect to the position change is small. As a result, there is a problem that detection accuracy is deteriorated. Further, as shown in FIG. 16, for example, two operation pen 8A on the surface of the light guide plate 10, if 8B is simultaneously contacted to the point _{P 1} and point _{P 2,} the imaging units 20 and 30, two operating pens 8A, 8B is likely to erroneously recognize that the present point _{P 3} and the point _{P 4.} Therefore, in the coordinate input module 3B of the present embodiment, as shown in FIG. 17, six imaging units 20, 30, 40, 50, 60, and 70 are provided as light receiving means.

  Specifically, three imaging units 20, 60, and 30 are provided on one first edge along the longitudinal direction of the light guide plate 10, and the first edge along the longitudinal direction of the light guide plate 10. Three imaging units 40, 70, and 50 are provided on the second edge facing the part.

  In this case, the light source units 4A and 4B are not arranged at the place where the central imaging units 60 and 70 are arranged. Thereby, it can prevent that the light of LED4a injects into the center imaging unit 60,70.

  Also in the coordinate input module 3B of the present embodiment, as shown in FIG. 18, the light source unit 4A at the first edge and the light source unit 4B at the second edge are alternately turned on.

Thus, as shown in FIG. 19, the coordinate contact position P ₂ of the operation pen 8 in proximity to the imaging units 20 and 30, even when the angle β in the viewing direction from the imaging unit 30 is small, the central By using the imaging unit 70, an angle β ′ in the viewing direction from the imaging unit 70 larger than the angle β in the viewing direction from the imaging unit 30 can be obtained.

  Thereby, the problem that the detection accuracy of the contact position of the operation pen 8 close to the imaging units 20 and 30 is deteriorated can be solved.

In addition, as shown in FIG. 20, when two operating pens 8 </ b> A and 8 </ b> B are simultaneously in contact with the points P < _b > ₁ and P <b> 2 on the surface of the light guide plate 10, the two operating pens 8 </ b> A, 8 </ b> A, obtaining the viewing angle of the _{P 1} and point _{P 2} point 8B. As a result, when using the imaging unit 20 and the imaging unit 60, apart from the point _{P 1} and point _{P 2,} 2 single operation pen 8A, 8B may have provided to the point _{P 5} and the point _{P 6} Detected. In this case, the points P ₁ and P ₂ obtained by the imaging units 20 and 30 shown in FIG. 16 coincide with the points P ₁ and P ₂ obtained by the imaging units 20 and 60 shown in FIG. As a result, by using the three imaging units 20, 30, 60 for the two operation pens 8 </ b> A, 8 </ b> B, the point P ₁ and the point P ₂ that are the contact positions of the two operation pens 8 </ b> A, 8 </ b> B on the light guide plate 10. Can be obtained accurately. In this method, generally, if N + 1 light receiving means are present for simultaneous contact of N (N is an integer of 2 or more) points on the light guide plate 10, N (N is an integer of 2 or more). ) It is possible to accurately detect simultaneous contact of points. In addition, as in the present embodiment, the light source units 4A and 4B are alternately controlled to blink using the six imaging units 20, 30, 40, 50, 60, and 70, thereby simultaneously operating the five points of the operation pen 8. Detection is possible.

  As described above, in the coordinate input module 3B, the first and second edge portions of the light guide plate 10 are provided with at least three or more imaging units 20, 60, 30 and imaging units 40, respectively, as light receiving means. 70, 50 are provided.

  As a result, even when the operation pen 8 is present at any location on the light guide plate 10, it is possible to prevent the contact position detection accuracy from being lowered. In addition, the contact position of each operation pen 8 can be accurately detected even in simultaneous contact of a plurality of operation pens 8.

  In the coordinate input module 3B, it is preferable that at least two light source units 4A and 4A and light source units 4B and 4B are provided on the first edge and the second edge of the light guide plate 10, respectively. Thereby, in order to obtain sufficient detection intensity in each of the three or more imaging units 20, 60, 30 and the imaging units 40, 70, 50, the light amount is increased by increasing the light source units 4A, 4A and the light source units 4B, 4B. It is possible to increase the detection accuracy.

  In the coordinate input system according to the present embodiment, the operation pen 8 is used as the detection object. However, in addition to the operation pen 8, another detection object such as a finger can be used together.

  It should be noted that the present invention is not limited to each embodiment, and various modifications are possible within the scope shown in the claims, and an implementation obtained by appropriately combining the technical means disclosed in each embodiment. The form is also included in the technical scope of the present invention.

  The present invention can be suitably used for a coordinate input system as a touch panel that realizes a touch function using an operation member (and a finger) such as a touch pen.

1 Coordinate input system 2 Liquid crystal display module (image display module)
2a Liquid crystal display panel 2b Chassis 2c Protective glass 3A, 3B Coordinate input module 4A, 4A Light source unit 4a LED
5 optical coupling member 5a prism 5b double-sided tape 5c transparent block 6 detector (detection means)
7 Light absorbing member 8, 8A, 8B Operation pen (operation member)
DESCRIPTION OF SYMBOLS 10 Light guide plate 11 Through-hole 11a Wall surface 13a, 14a Propagation light 20, 30, 40, 50, 60, 70 Imaging unit (light-receiving means)
21, 31, 41 Lenses 22, 32, 42 Optical filters 23, 33, 43 Image sensor 81, 81 'Pen tip portion 82 Handle portion 83, 83' Light scattering portion 84, 84 'Light reflecting portion 85 Contact surface 86, 86 'light reflecting surface L interval

Claims (6)

A light guide plate through which light propagates;
An operation member in contact with the upper surface of the light guide plate;
A plurality of light extraction portions for extracting a part of the light propagating through the light guide plate at a plurality of locations apart from each other in the light guide plate;
A light receiving means for receiving the light extracted by each of the light extraction units;
The traveling direction of the light extracted from the two light extraction portions separated from each other in the light guide plate is obtained from the light reception result of the light receiving means, and from the traveling direction and the separation distance of the two light extraction portions, Detecting means for detecting the position coordinates of the contact object in contact with the upper surface of the light guide plate,
The operation member has a tip portion provided with a contact surface that comes into contact with the upper surface of the light guide plate, and the tip portion transmits light that propagates through the light guide plate from the contact surface in contact with the upper surface of the light guide plate. Is incident on the light guide plate again from the contact surface that is in contact with the upper surface of the light guide plate by scattering the incident light,
The input device characterized in that the plurality of light extraction units extract part of the propagation light propagating in the light guide plate from the scattered light incident on the light guide plate from the contact surface in contact with the upper surface of the light guide plate. .   The light emitting portion provided with the contact surface that scatters the incident light and the light reflecting portion that reflects the light are provided at the tip portion. Input device. The light reflecting portion has a convex curved surface that is convex toward the light reflecting side,
The input device according to claim 2, wherein the light scattering portion is located between the convex curved surface and the contact surface.   The said front-end | tip part is comprised from the material which the area of the said contact surface spreads by the press at the time of the said contact surface contacting the upper surface of a light-guide plate, The any one of Claim 1 to 3 characterized by the above-mentioned. The input device described. The light scattering portion is a container-like structure that is convex toward the contact surface, and the container-like structure is made of a resin having light scattering properties,
The input device according to claim 2, wherein the light reflecting portion is a spherical structure housed in the container-like structure, and is made of metal. An input device according to any one of claims 1 to 5,
An image display panel having a plurality of pixels,
An input system for driving the pixels of the image display panel based on the position coordinates detected by the detection means.

Images