JP2013250817A - Coordinate input device and coordinate input system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an area of a frame of a coordinate input device, and make a front face including a surface to be contacted by a detected body fully flat, and a coordinate input system.SOLUTION: A coordinate input device 3A comprises: a plate-like light guide plate 10; a light source unit 4A that causes light to be made incident on the light guide plate 10; at least two imaging units 20 and 30, and 40 and 50; and a detection unit 6 that detects, when the surface of the light guide plate 10 is contacted by a finger 8, coordinates of a contact position of the finger 8 on the surface of the light guide plate 10 on the basis of outputs of imaging units 20, 30, 40, and 50 that have detected propagation light inside the light guide plate 10 based on the contact. The imaging units 20, 30, 40, and 50, and light source unit 4A are provided on a back side of the light guide plate 10.

Description

  The present invention relates to a plate-shaped light guide member, a light source that makes light incident on the light guide member, at least two light receiving means, and the contact based on the contact when the object to be detected contacts the surface of the light guide member. Coordinate input device and coordinate input provided with detection means for detecting the coordinates of the position of contact of the light guide member with the surface of the light guide member based on the output of the light receiving means that has detected the propagation light inside the light guide member It is about the system.

  An optical coordinate input device or position detection device comprising a bar-shaped operation member (hereinafter referred to as “pen”) such as a touch pen or a stylus pen, or a light guide member that receives coordinate input by a finger or the like, and a coordinate input device or A coordinate input system such as a tablet or a touch panel in which a position detection device and a display panel are combined is known.

  In the coordinate input system, the coordinate input device or the position detection device obtains the coordinates of the approached or touched position of the pen or finger by causing the pen or finger to approach or contact the coordinate input area of the coordinate input device. The obtained coordinates are 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 integrally laminated on the coordinate input device. Used for etc.

  For example, as shown in FIGS. 18A and 18B, the touch panel 100 disclosed in the first embodiment of Patent Document 1 includes a light guide plate 101, a light source 102 that makes light incident on the light guide plate 101, and The light receiving elements 104 and 105 arranged on a part of the side surface of the light guide plate 101 and the light from the light source 102 scattered by the detected object 110 between the side surface of the light guide plate 101 and the light receiving elements 104 and 105 are received by the light receiving element 104. An image forming unit 107 that forms an image on 105 is provided. Further, a light absorbing means 108 is disposed on the side surface of the light guide plate 101 where the light receiving elements 104 and 105 are disposed, and the light receiving elements 104 and 105 are located outside the irradiation range of the light source 102 as shown in FIG. Has been placed.

  The principle of coordinate detection of the touch panel 100 is as follows.

  Light emitted from the light source 102 disposed on the side surface of the light guide plate 101 propagates while repeating total reflection inside the light guide plate 101. In a state where the detected object 110 such as a finger is not touched on the light guide plate 101, the light receiving elements 104 and 105 are arranged outside the irradiation range of the light source 102, and thus do not receive the propagation light propagating inside the light guide plate 101. On the other hand, when the detection object 110 such as a finger is touched on the transparent light guide plate 101, the propagation light in the light guide plate 101 is disturbed at the touch position of the detection object 110, and scattered light is generated. A part of the scattered light also propagates in the direction of the light receiving elements 104 and 105, and is received by the light receiving elements 104 and 105 as shown in FIGS. Thereby, the azimuth angle is measured, and the point where the scattered light is generated by the triangulation method, that is, the point where the detected object 110 such as a finger is touched is specified.

  In the third embodiment of Patent Document 1, as shown in FIGS. 20A and 20B, the light source 102a, the light receiving element 104a, the light source 102b, and the light receiving element 104b are respectively disposed on the opposite end surfaces of the light guide plate 101. There is described a touch panel 100 ′ that can be arranged and light sources 102a and 102b are alternately turned on to eliminate the influence of light directly reaching the light receiving elements 104a and 104b. Accordingly, it is possible to increase the degree of freedom of arrangement of the light sources 102a and 102b and the light receiving elements 104a and 104b.

  By the way, in such a touch panel 100 ′, there are cases where it is desired to have a plurality of detected bodies such as fingers. In such a case, when there are only two light receiving elements, as shown in FIG. 13, there are a plurality of possible combinations of contact positions on the detection target such as a finger, and the contact positions cannot be determined. In this case, by using at least three light receiving elements, it is possible to determine the contact position on the detection object such as a plurality of fingers.

JP 2009-258967 A (published on November 5, 2009)

  However, in the conventional touch panel 100 disclosed in Patent Document 1, the light source 102 and the light receiving elements 104 and 105 are arranged on the side surface of the light guide plate 101. In the touch panel 100 ′, the light sources 102 a and 102 b and the light receiving elements 104 a and 104 b are arranged on the side surface of the light guide plate 101. For this reason, the touch panel 100/100 'of Patent Document 1 has a problem that the frame size is increased by the light source 102, the light sources 102a / 102b, the light receiving elements 104/105, and the light receiving elements 104a / 104b.

  In the touch panel 100 of Patent Document 1, a part of the light source 102 and the light receiving elements 104 and 105 protrude from the upper surface of the light guide plate 101. For this reason, it has a problem that it is difficult to realize full flatness of the front surface including the surface to be detected touched on the touch panel 100.

  The present invention has been made in view of the above-described conventional problems, and its object is to provide a coordinate input device and coordinates capable of realizing a narrow frame and full flattening of a front surface including a surface with which a detected object is contacted. To provide an input system.

  In order to solve the above problems, the coordinate input device of the present invention includes a plate-shaped light guide member, a light source that makes light incident on the light guide member, at least two light receiving means, and a surface of the light guide member. Based on the output of the light receiving means that detects the propagation light inside the light guide member based on the contact when the detection body is contacted, the coordinates of the contact position on the surface of the light guide member on the detected body are detected. A coordinate input device including a detecting unit, wherein the light receiving unit and the light source are provided on a back surface of the light guide member.

  According to said invention, the light-receiving means and light source of a coordinate input device are provided in the back surface in the said light guide member.

  Therefore, since there is nothing present on the side surface of the light guide member, the frame size can be reduced. Moreover, since the light receiving means and the light source are provided on the back surface of the light guide member, a part thereof does not protrude from the surface of the light guide member.

  Therefore, it is possible to provide a coordinate input device that can realize narrowing of the frame and full flattening of the front surface including the surface with which the detection object is contacted.

  In the coordinate input device of the present invention, the plate-like light guide member has a rectangular planar shape, and the light receiving means and the light source have a first edge portion and a second edge facing each other in the light guide member. It is preferable to be provided at the edge.

  In the coordinate input device of the present invention, in the state where the amount of light received by the light receiving means is maintained at 0, for example, the received light peak of scattered light due to the presence of a detection object such as a finger is detected.

  Here, in the touch panel of Patent Document 1, light is incident only from one direction of the end face of the light guide member. For this reason, for example, when there are a plurality of objects to be detected, it may be possible to add light receiving means corresponding to them, but there is no place to add the light receiving means due to the presence of the light absorbing means on the opposite end face of the light source. As a result, there is a problem that multipoint detection cannot be performed.

  Therefore, in the coordinate input device of the present invention, the plate-shaped light guide member has a rectangular planar shape, and the light receiving means and the light source include the first edge of the light guide member and the first edge. And a second edge facing the portion.

  By the way, when the light receiving means and the light source are provided on the first edge of the light guide member and the second edge opposite to the first edge, respectively, the first edge is provided. When the light source of the light source and the light source of the second edge portion facing the first edge portion are simultaneously turned on, the light from the light sources facing each other is incident on the light receiving means. Scattered light due to cannot be detected.

  Therefore, in the present invention, for example, the light source at the first edge and the light source at the second edge can be turned on alternately. Specifically, the contact position on the surface of the light guide member on the detected body by the light receiving means provided on the first edge during the period when the light source at the first edge of the light guide member is lit. Detect the coordinates of. On the other hand, during the period when the light source at the second edge of the light guide member is lit, the coordinates of the position of contact of the light guide member with the surface of the light guide member by the light receiving means provided at the second edge are determined. To detect.

  Therefore, in the optical coordinate input device using the light guide member, it is possible to provide a coordinate input device that can detect the coordinate positions of a plurality of detection objects.

  In the coordinate input device of the present invention, the light receiving means and the light source are provided on the first edge and the second edge facing each other in the light guide member. For this reason, when the detected object is brought into contact with the rectangular light guide member, the contact position of the detected object can be detected using the light receiving means and the light source close to the contact position. This means that the contact position of the detection target can be detected even if the light guide member is enlarged.

  Therefore, an optical coordinate input device using a light guide member can provide a coordinate input device that can detect the coordinate position of a detection object such as a finger even when applied to a large touch panel.

  In the coordinate input device of the present invention, the light source is preferably provided in a linear shape.

  That is, in the present invention, in order to use the triangulation method, at least two light receiving means and a light source are provided on each of the first edge and the second edge facing each other in the light guide member. . Therefore, the light source is provided between the two light receiving means. In this case, if the light source is a single light source, the light from the light source spreads radially at an angle smaller than 180 degrees, so that an area that cannot be irradiated occurs in the light guide member. As a result, in the light guide member, even if a detected object such as a finger is brought into contact with the light guide member, scattered light is not generated, and the coordinate position cannot be detected.

  In this regard, in the present invention, since the light source is provided in a linear shape and can irradiate the entire region of the light guide member, a region where the coordinate position cannot be detected does not occur on the light guide member.

  Moreover, in this invention, as above-mentioned, the light-receiving means and the light source are provided in the 1st edge part and 2nd edge part which mutually oppose in a light guide member. In this case, for example, when detecting a detected object such as a finger that is in contact with the light guide member, the light receiving means detects scattered light based on the contact of the detected object such as the finger with the light guide member. become. In this case, if the light source is a single light, the amount of light incident on the light receiving means is small, so that the detection accuracy is lowered. Thus, by using a linear light source as the light source, the light amount of the light source can be increased, and thereby the amount of scattered light incident on the light receiving means can be increased.

  Therefore, it is possible to provide a coordinate input device that can improve detection accuracy.

  In the coordinate input device of the present invention, it is preferable that a light absorbing member is provided on at least the first and second edge portions of the light guide member on the light guide member surface and the light guide member back surface. It should be noted that not only the first edge and the second edge but also that the light absorbing member is provided on another pair of edges different from the first edge and the second edge.

  That is, light is emitted from the light source provided at the first edge and the second edge facing each other toward the second edge and the first edge facing each other, and most of the propagation light is guided. Emission from each end of the optical member. However, a part of the propagation light is reflected as stray light at the end of the light guide member, emitted from the edge of the light guide member, and when this emitted light is incident on the light guide member again, it is directed to the light receiving means. Noise signal. However, in the present invention, since the light absorbing member is provided on at least the first and second edge portions of the light guide member on the light guide member surface and the light guide member back surface, Unnecessary light such as outside light and stray light can be blocked. Moreover, since the light absorption member is provided at the first edge and the second edge, the light absorption member can be easily provided.

  In order to solve the above problems, a coordinate input system according to the present invention is a coordinate input system including the coordinate input device described above, and includes an image display module.

  According to said invention, a coordinate input device can be functioned as a touch panel which inputs with to-be-detected bodies, such as a finger, seeing the image of an image display module. Therefore, it is possible to provide a coordinate input system including a coordinate input device that can realize a narrow frame and full flatness of a front surface including a surface with which a detection object is contacted.

  As described above, in the coordinate input device of the present invention, the light receiving means and the light source are provided on the back surface of the light guide member.

  As described above, the coordinate input system of the present invention is a coordinate input system including the coordinate input device described above, and includes an image display module.

  Therefore, there is an effect of providing a coordinate input device and a coordinate input system capable of realizing a narrow frame and full flattening of a front surface including a surface with which a detection object is contacted.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a coordinate input device and a coordinate input system according to an embodiment of the present invention, and is a perspective view illustrating an optical path of propagation light when a finger is brought into contact with a light guide plate in the coordinate input device. It is a disassembled perspective view which shows the whole structure of the coordinate input system provided with the said coordinate input device. (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. 2 illustrates a configuration of a coordinate input system, and is a cross-sectional view taken along line AA in FIG. 1. It is a top view which shows the irradiation area | region to the light-guide plate in one LED. (A) (b) is sectional drawing which shows the structure of the optical coupling member provided between the light-guide plate and LED. (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 in which 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 in a 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. (A) is a perspective view which shows the structure of the position detection apparatus as a conventional coordinate input device, (b) is a top view which shows the structure of the principal part of the said position detection apparatus. (A) is a top view which shows the detection principle of the position detection apparatus as the said conventional coordinate input device, (b) is a wave form diagram which shows the optical signal of the light receiving element in the said position detection apparatus. (A) and (b) are the top views which show the structure of the modification in the position detection apparatus as said conventional coordinate input device, and show the lighting control method of a light source.

[Embodiment 1]
One embodiment of the present invention will be described below with reference to FIGS.

(Configuration of coordinate input system)
A configuration of a coordinate input system including the coordinate input device according to the present embodiment will be described with reference to FIGS. 2 and 3A and 3B. FIG. 2 is an exploded perspective view showing the configuration of the coordinate input system. FIG. 3A is a plan view showing the configuration of the coordinate input system, and FIG. 3B is a side sectional view showing the configuration of the coordinate input system. In this specification, the Z direction in FIG. 2 is the front side of the coordinate input system. 2 is the longitudinal direction of the coordinate input system, and the Y direction in FIG. 2 is the short direction of the coordinate input system.

  As shown in FIG. 2, the coordinate input system 1 according to the present embodiment includes a liquid crystal display module 2 as an image display module and a coordinate input device 3 </ b> A provided on the front side of the liquid crystal display module 2. .

  As shown in FIGS. 3A and 3B, the liquid crystal display module 2 has a liquid crystal layer sandwiched between a pair of substrates (not shown), and the liquid crystal molecules of the liquid crystal layer are aligned on each substrate by voltage application. And a liquid crystal display panel 2a provided with various electrodes for changing. In the liquid crystal display panel 2a, a desired display is performed by adjusting the amount of light transmitted through the liquid crystal layer of each pixel by changing the orientation of the 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. Note that a conventionally known liquid crystal display module can be used as the configuration of the liquid crystal display module 2.

  In the coordinate input system 1, for example, a finger as a detection object is brought into contact with the light guide plate 10 of the coordinate input device 3 </ b> A provided on the front side of the liquid crystal display panel 2 a while viewing the screen displayed on the liquid crystal display panel 2 a. Thus, the coordinates of the contact position on the finger are specified, and desired data can be input.

(Configuration of coordinate input device)
Next, the configuration of the coordinate input device 3A provided in the coordinate input system 1 will be described with reference to FIGS. 2, 3 (a) and 3 (b), and FIGS. 1, 4 (a), (b) to 7 (a). ) (B) will be described in detail below. FIG. 1 is a perspective view showing an optical path of scattered light when the finger 8 touches the light guide plate 10. 4A is a side view showing the configuration of the coordinate input system 1, and FIG. 4B is an enlarged side view showing the configuration of the edge of the coordinate input system 1. As shown in FIG. FIG. 5 shows the configuration of the coordinate input system 1, and is a cross-sectional view taken along line AA in FIG. FIG. 6 is a plan view showing an irradiation area to the light guide plate 10 in one LED. 7A and 7B are cross-sectional views showing the configuration of the optical coupling member provided between the light guide plate 10 and the LED 4a.

  As shown in FIGS. 2 and 3A and 3B, the coordinate input device 3 </ b> A is disposed at a corner portion of the light guide plate 10 as a rectangular transparent light guide member and the rectangular light guide plate 10. From the image pickup units 20, 30, 40, 50 as the received light receiving means, the light source units 4A, 4B as the light sources provided on the back sides of both sides in the longitudinal direction of the light guide plate 10, and the light source units 4A, 4B An optical coupling member 5 that couples light to the light guide plate 10 and a detection unit 6 as detection means described later are provided. Moreover, as shown in FIG.3 (b), the light absorption members 7 and 7 are provided in the surface side and back surface side of the location in which the light source unit 4A * 4B in the edge part in the light-guide plate 10 is arrange | positioned. .

  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 corners, corners are notched, or corners are curved. It may be a substantially quadrangular shape.

  As shown in FIGS. 3A and 3B, the light guide plate 10 is configured so that the periphery of the four sides is larger than the liquid crystal display panel 2a. Accordingly, the imaging units 20, 30, 40, and 50 can be disposed on the back side of the light guide plate 10. As a result, an increase in the size of the coordinate input device 3A in the direction of spreading along the contact surface with the light guide plate 10 of the finger 8 described later is suppressed, which contributes to the realization of the compact size of the coordinate input device 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 larger, such as 60 inches, 70 inches, 80 inches, 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, 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, since the imaging units 20, 30, 40, and 50 are sealed, no foreign matter is mixed into the imaging units 20, 30, 40, and 50.

  Further, at the four corners of the light guide plate 10 where the imaging units 20, 30, 40, 50 are disposed, as shown in FIGS. 4 (a) and 4 (b), a concave conical optical path conversion unit is provided. The through-holes 11 are respectively 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.

  As shown in FIG. 5, the angle γ formed between the conical wall surface 11a 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. 5, 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 light conversion member is provided as the through hole 11 in the corner portion of the light guide plate 10, the light conversion member is prevented from protruding from the light guide plate 10.

  Next, the imaging units 20, 30, 40, and 50 are disposed 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, and 50 have a structure that does not protrude above the surface of the light guide plate 10.

  Further, in the coordinate input device 3 </ b> A of the present embodiment, the imaging units 20, 30, 40, and 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 provided in at least two places on the second edge. As will be described later, in the coordinate input device 3A of the present embodiment, the reason is that the imaging units 20 and 30 on one first edge of the light guide plate 10 and the second edge of the other side of the light guide plate 10 This is because the imaging units 40 and 50 are used alternately. That is, 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. 5, 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. 5 transmit the light in the wavelength band emitted from the finger 8 and play the role of blocking the light in the other wavelength bands. The optical filters 22 and 42 and the like block sunlight and stray light such as backlight light for a liquid crystal display panel, and can increase the SN ratio. However, in the detection of scattered light due to the contact of the finger 8, it is sufficient to take a difference from the background video signal, so an optical filter is not necessarily required.

  In addition, the image pickup devices 23, 33, 43, and the like according to the present embodiment are composed 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 image pickup devices 23, 33, and 43 are arranged so as to be parallel to the surface of the light guide plate 10.

  The imaging units 20, 30, 40, and 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, and 43.

  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 ultraviolet light. That is, since the coordinate input system 1 has the coordinate input device 3A disposed on the front surface of the liquid crystal display panel 2a, the wavelength of the light source units 4A and 4B is preferably non-visible light. 53 is generally composed of a silicon-based light-receiving element, and is preferably infrared because of its sensitivity characteristics.

  Further, it is not always necessary to use the LED 4a, and an LD (laser diode) or the like can also be used.

  Here, in the present embodiment, 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 device 3A of the present embodiment, the imaging units 20 and 30 and the light source unit 4A are provided on one 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 respectively provided on the other second edge facing the first edge. In this case, since the light source units 4A, 4B and the imaging units 20, 30, 40, 50 are all provided on the back side of the light guide plate 10, the light source units 4A, 4B are the imaging units 20, 30 or imaging units. 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. 5, 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, and 50, direct light from the light source units 4 and 4 does not enter the signal detection effective area of the imaging units 20, 30, 40, and 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 along the longitudinal direction of the light guide plate 10. The reason for this is that, as shown in FIG. 6, the LED 4 a is provided on both sides along the longitudinal direction of the light guide plate 10 and on the second edge, and the edges of both sides along the short side of the light guide plate 10. This is because the light reaching distance of the LED 4a in the light guide plate 10 is shorter than the case where the light guide plate 10 is provided. That is, this increases the amount of light from the light source units 4A and 4B, and also reduces the distance from the finger 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 scattered light from the finger 8 at the imaging units 20, 30, 40, and 50 increases.

  Here, when the scattered light from the finger 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. 6, 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. 2, optical coupling members 5 and 5 are provided between the light guide plate 10 and the light source units 4A and 4B, as shown in FIGS. 7 (a) and 7 (b). In addition, the light from the LEDs 4a of the light source units 4A and 4B is incident on the light guide plate 10 through the optical coupling members 5 and 5 at an angle.

  Specifically, as shown in FIG. 7A, 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 obliquely on the light guide plate 10 as shown in FIG.

  As shown in FIG. 7B, 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.

  Next, as shown in FIG. 1, the coordinate input device 3A is provided with a detection unit 6 as detection means. The detection unit 6 detects outputs from the image pickup devices 23 and 33 based on light scattering by the finger 8 and obtains coordinates of a contact position of the finger 8 on the surface of the light guide plate 10. Specifically, it consists of a CPU.

  Further, light absorbing members 7 and 7 are 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 and 4B and the imaging units 20, 30, 40, and 50. Yes. The light absorbing members 7 and 7 are formed by sticking a high light-shielding film made of, for example, a black polyester film or the like to the light guide plate 10 so that the reflected light at the end of the light guide plate 10 returns to the opposite end. So that the reflected light is absorbed.

  Here, in the coordinate input system 1 of this Embodiment, the finger | toe 8 is used as a to-be-detected body, for example. However, the detection target is not necessarily limited to the finger 8 and may be a detected object such as a stick-shaped touch pen.

(Coordinate detection principle of coordinate input device)
With respect to the coordinate detection principle when the finger 8 is brought into contact with the light guide plate 10 in the coordinate input device 3A having the above-described configuration, FIG. 1, FIG. 5, FIG. 8 (a) (b) and FIG. 9 (a) (b) Based on FIG. 8A is a plan view showing the detection principle of the coordinate input device 3A, and FIG. 8B is a waveform diagram showing an optical signal of the image sensor in the imaging unit of the coordinate input device 3A. FIG. 9A is a plan view showing a contact position when a finger is brought into contact with various places on the surface of the light guide plate, and FIG. 9B shows a detection image of the image sensor corresponding to the contact position of the finger. It is a wave form diagram which shows the relationship between the pixel number which appears and signal strength.

  First, in the coordinate input device 3A, as shown in FIG. 5, light is obliquely incident on the light guide plate 10 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. 5, 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 and 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. 5, when the finger 8 is brought into contact with, or touched with, the surface of the light guide plate 10, the total reflection condition in the light guide plate 10 is broken, and the finger 8 passes through the light guide plate 10 having the refractive index n. Part of the infrared light that is guided 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. 1, infrared light that is scattered light of the finger 8 is diffused radially with respect to the two-dimensional plane of the light guide plate 10 and propagates through the light guide plate 10. A part of the propagation light 13a / 14a of the luminous flux is also guided to the wall surfaces 11a / 11a of the conical through holes 11/11, and the reflected light of the wall surfaces 11a / 11a is captured by the imaging units 20/30. The light is received at. Specifically, the reflected light of the wall surfaces 11a and 11a of the through holes 11 and 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. Light is received by the image sensors 23 and 33. As a result, as shown in FIG. 8B, 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, so that the light guide plate 10 at the location where the finger 8 is in contact is shown in FIG. Angles α and β, which are viewing angles from the imaging units 20 and 30 in the two-dimensional plane, are obtained.

For example, as shown in FIG. 9A, when the finger 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 device 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. 9B, it can be generally 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.

(Calculation method of 2D coordinate position)
Next, a method for calculating the two-dimensional coordinate position of the light guide plate 10 at the location where the finger 8 is in contact will be described with reference to FIGS. This processing is performed by the detection unit 6. Here, FIG. 10A is a perspective view illustrating an imaging state of the imaging unit 20 in the coordinate input device 3A, and FIG. 10B is a plan view illustrating an image of the imaging element 23 of the imaging unit 20. . 10 (a) and 10 (b), only the imaging unit 20 will be described, but the same processing is performed in the imaging unit 30 as well.

  As shown in FIG. 5 and FIG. 10A, 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 varies depending on the position of the finger 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 finger 8 are obtained using triangulation.

Specifically, in FIG. 10 (a), the time the finger 8 is in the position of point P _1, as shown in FIG. 10 (b), the linear image 25 is formed. Also, the fingers 8 when moved to the position of the point P _2, the image 27 of the line shape is formed.

  When the light from the light source unit 4A is irradiated, when the finger 8 is not in contact with the light guide plate 10, no change occurs in the acquired images of the image sensors 23 and 33. On the other hand, when the finger 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 are applied to the imaging surfaces of the imaging elements 23 and 33. 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. 10B changes depending on the position of the contact point on the finger 8, and when the position of the contact point on the finger 8 is changed, the linear image 25 becomes linear. It changes like an 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 linear image 25 (with the center of the circular arc as the rotation center) is the line segment connecting the finger 8 and the image pickup device 23 and the light guide plate 10 described above. 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 finger 8 moves 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 the angle β formed by the line segment connecting the finger 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 finger 8 touches 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 device 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 coordinates of the finger 8 obtained by the above method, the pixel at the position corresponding to the position coordinates of the liquid crystal display panel 2a is driven, and the user visually recognizes the touch position of the finger 8. Is possible. 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.

(Coordinate detection method for contact position on multiple fingers)
In the coordinate input device 3A of the present embodiment, even when a plurality of fingers 8 are in contact with the light guide plate 10, the coordinate position of each finger 8 can be detected without hindrance. A configuration for this will be described with reference to FIG. FIG. 11 is an explanatory diagram showing a configuration for enabling detection even when a plurality of fingers 8 touch the light guide plate 10 in the coordinate input device 3A of the present embodiment.

  As described above, the coordinate input device 3A of the present embodiment includes the plate-shaped light guide plate 10, the light source units 4A and 4B that allow light to enter the light guide plate 10, and at least two imaging units 20, 30, 40, and so on. 50 and the light guide plate in the finger 8 based on the output of the imaging units 20, 30, 40, and 50 that detect light scattering by the finger 8 when the detected object such as the finger 8 contacts the surface of the light guide plate 10. And a detection unit 6 that detects the coordinates of the position of contact with the surface of 10.

  In such a coordinate input device 3A, the light reception peak of the scattered light due to the presence of the detection object such as the finger 8 is detected in a state where the light reception change amount of the imaging units 20, 30, 40, and 50 is maintained at zero.

  Here, in the touch panel of Patent Document 1, light is incident only from one direction of the end face of the light guide member. For this reason, for example, when there are a plurality of objects to be detected, it may be possible to add light receiving means corresponding to them, but there is no place to add the light receiving means due to the presence of the light absorbing means on the opposite end face of the light source. As a result, there is a problem that multipoint detection cannot be performed.

  Therefore, in the coordinate input device 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 respectively provided on the second edge portion facing the first edge portion along the longitudinal 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 and 30 or the imaging units 40 and 50, the scattered light due to the contact of the finger 8 cannot be detected.

  Therefore, in the present embodiment, as shown in FIG. 11, the light source unit 4A at the first edge and the light source unit 4B at the second edge are lit alternately. 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 part in the light-guide plate 10 is lighting, the contact to the surface of the light-guide plate 10 in the finger | toe 8 in the imaging unit 20 * 30 provided in this 1st edge part Detect position coordinates. On the other hand, in the period when the light source unit 4B at the second edge of the light guide plate 10 is lit, the imaging unit 40, 50 provided at the second edge contacts the surface of the light guide plate 10 with the finger 8. Detect position coordinates.

  As a result, 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 contact of the finger | toe 8 is detectable. As a result, for example, when the finger 8A as the first detected body and the finger 8B as the second detected body are simultaneously in contact with the light guide plate 10, the detection signals of the imaging units 20, 30, 40, and 50 are detected. Can be separated and detected. Strictly speaking, since the signal detection of the imaging units 40 and 50 at the second edge that is the upper side and the signal detection of the imaging units 20 and 30 at the first edge that 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 finger 8A that touches first and the finger 8A that touches later. However, by removing the data of the finger 8 detected by the previous lighting of the light source unit 4A, the finger 8A due to the subsequent lighting of the light source unit 4A can be detected. Therefore, the coordinates of the contact position of each finger 8 can be obtained even when three or more fingers 8 are in contact with the light guide plate 10.

  Further, as will be described later in Embodiment 2, it is possible to simultaneously detect three or more fingers 8 by increasing the number of light receiving means.

  Thus, in the coordinate input device 3A of the present embodiment, the plate-shaped light guide plate 10, the light source units 4A and 4B that allow light to enter the light guide plate 10, and at least two imaging units 20, 30, 40, and 50. And based on the output of the imaging units 20, 30, 40, and 50 that detect the propagation light inside the light guide plate 10 based on the contact when the detected object such as the finger 8 comes into contact with the surface of the light guide plate 10. And a detecting unit 6 for detecting the coordinates of the position of contact of the detected object with the surface of the light guide plate 10.

  In such a coordinate input device 3A, as disclosed in the touch panel of Patent Document 1, the light receiving element and the light source are disposed on the side surface of the light guide plate, and thus there is a problem that the frame size becomes large. It was. In addition, since a part of the light receiving element and the light source protrudes from the upper surface of the light guide plate, it is difficult to realize full flattening of the front surface including the surface to be detected touched on the touch panel. Had.

  On the other hand, in the coordinate input device 3 </ b> A of the present embodiment, the imaging units 20, 30, 40, and 50 and the light source units 4 </ b> A and 4 </ b> B are provided on the back surface of the light guide plate 10. Therefore, since there is nothing present on the side surface of the light guide plate 10, the frame size can be reduced. Further, since the imaging units 20, 30, 40, and 50 and the light source units 4 </ b> A and 4 </ b> B are provided on the back surface of the light guide plate 10, some of them do not protrude from the surface of the light guide plate 10.

  Therefore, it is possible to provide the coordinate input device 3A that can realize the narrowing of the frame and the full flatness of the front surface including the surface with which the detected object is contacted.

  In the coordinate input device 3A of the present embodiment, the planar light guide plate 10 has a rectangular planar shape, and the imaging units 20, 30, 40, and 50 and the light source units 4A and 4B have a light guide plate. 10 are preferably provided at the first and second edges facing each other.

  In the coordinate input device 3A of the present embodiment, in the state where the received light amount of the imaging units 20, 30, 40, and 50 is maintained at 0, for example, the received light peak of scattered light due to the presence of the detected object such as the finger 8 is detected. It is supposed to be.

  Here, in the touch panel of Patent Document 1, light is incident only from one direction of the end face of the light guide member. For this reason, for example, when there are a plurality of objects to be detected, it may be possible to add light receiving means corresponding to them, but there is no place to add the light receiving means due to the presence of the light absorbing means on the opposite end face of the light source. As a result, there is a problem that multipoint detection cannot be performed.

  Therefore, in the coordinate input device 3A of the present embodiment, the planar light guide plate 10 has a rectangular planar shape, and the imaging units 20, 30, 40, and 50 and the light source units 4A and 4B include the light guide plate. 10 and a second edge facing the first edge, respectively.

  By the way, the imaging units 20, 30, 40, and 50 and the light source units 4 </ b> A and 4 </ b> B are thus formed on the first edge portion of the light guide plate 10 and the second edge portion that faces the first edge portion. When the light source unit 4A at the first edge and the light source unit 4B at the second edge opposite to the first edge are turned on at the same time, the imaging units 20, 30, 40 are provided. Since light from the light source units 4A and 4B facing each other is incident on 50, scattered light due to contact of a detection target such as the finger 8 cannot be detected.

  Therefore, in the present embodiment, for example, the light source unit 4A at the first edge and the light source unit 4B at the second edge can be turned on alternately. Specifically, in the detection target such as the finger 8 in the imaging units 20 and 30 provided at the first edge during the period when the light source unit 4A at the first edge of the light guide plate 10 is lit. The coordinates of the position of contact with the surface of the light guide plate 10 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 light guide plate 10 at the detection object such as the finger 8 by the imaging units 40 and 50 provided at the second edge. Detect the coordinates of the contact position on the surface.

  Therefore, in the optical coordinate input device using the light guide plate 10, it is possible to provide the coordinate input device 3 </ b> A that can detect the coordinate positions of the detected objects such as the plurality of fingers 8.

  In the coordinate input device 3A of the present embodiment, the imaging units 20, 30, 40, 50 and the light source units 4A, 4B are provided on the first edge and the second edge of the light guide plate 10 that face each other. It has been. For this reason, when the detected object comes into contact with the rectangular light guide plate 10, the contact position of the detected object is detected using the imaging units 20, 30, 40, and 50 and the light source units 4A and 4B that are close to the contact position. be able to. This means that the contact position of the detection target can be detected even if the light guide member is enlarged.

  Therefore, the optical coordinate input device 3A using the light guide plate 10 can provide the coordinate input device 3A that can detect the coordinate position of the detection object such as the finger 8 when applied to a large touch panel.

  In the coordinate input device 3A of the present embodiment, the light source units 4A and 4B are provided in a linear shape.

  That is, in the present embodiment, in order to use the triangulation method, at least two imaging units 20 and 30 and a light source unit are provided on each of the first edge and the second edge facing each other in the light guide plate 10. 4A, imaging units 40 and 50, and a light source unit 4B are provided. Therefore, the light source units 4A and 4B are provided between the two imaging units 20 and 30 or the imaging units 40 and 50. In this case, if the light source units 4A and 4B are a single light source, the light from the light source spreads radially at an angle smaller than 180 degrees, so that an area that cannot be irradiated on the light guide plate 10 is generated. As a result, in the light guide plate 10, even if a detection target such as the finger 8 is brought into contact with the light guide plate 10, scattered light is not generated and the coordinate position cannot be detected.

  In this respect, in the present embodiment, the light source units 4A and 4B are provided in a linear shape and can irradiate the entire region of the light guide plate 10, so that a region where the coordinate position cannot be detected is generated on the light guide plate 10. There is no.

  In the present embodiment, as described above, the imaging units 20, 30, 40, and 50 and the light source units 4A and 4B are provided on the first and second edges of the light guide plate 10 that face each other. It has been. In this case, for example, when detecting a detected object such as the finger 8 that is in contact with the light guide plate 10, scattered light based on contact of the detected object such as the finger 8 with the light guide plate 10 is captured by the imaging units 20 and 30.・ It will be detected at 40 ・ 50. In this case, if the light source units 4A and 4B are a single light, the amount of light incident on the image pickup units 20, 30, 40, and 50 becomes small, so that the detection accuracy decreases. Thus, by using a linear light source as the light source, the light amount of the light source can be increased, and thereby the amount of scattered light incident on the light receiving means can be increased. Therefore, a coordinate input device 3A that can improve detection accuracy can be provided.

  In the coordinate input device 3 </ b> A of the present embodiment, light absorbing members 7 and 7 are provided on the front and back surfaces of at least the first edge and the second edge of the light guide plate 10.

  That is, light is emitted from the light source units 4A and 4B provided at the first edge and the second edge facing each other toward the second edge and the first edge facing each other. The propagating light is emitted from each end of the light guide plate 10. However, when a part of the propagation light is reflected as stray light at the end of the light guide plate 10 and emitted from the edge of the light guide plate 10, and this emitted light is incident on the light guide member again, the imaging unit 20. -Noise signal to 30, 40, 50. However, in the present embodiment, since the light absorbing members 7 and 7 are provided at least on the front and back surfaces of the light guide plate 10 at the first edge and the second edge, Thus, unnecessary light such as outside light and stray light can be shielded. Moreover, since the light absorption members 7 and 7 are provided at the first edge and the second edge, the light absorption members 7 and 7 can be easily provided.

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

  According to said structure, 3 A of coordinate input devices can be functioned as a touchscreen which inputs with to-be-detected bodies, such as the finger | toe 8, while seeing the image of the liquid crystal display module 2. FIG. Therefore, it is possible to provide the coordinate input system 1 including the coordinate input device 3 </ b> A that can realize the narrowing of the frame and the full flatness of the front surface including the surface with which the detected object such as the finger 8 is brought into contact.

  In the coordinate input device 3A of the present embodiment, a device using a non-light-emitting detection object such as a finger 8 has been described. However, the present invention is not limited to this, and for example, a light-detection pen or the like is detected. It is possible to apply also about what uses a body.

[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 the first embodiment are given the same reference numerals, and explanation thereof is omitted.

  In the coordinate input device 3A of the first 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 , And the second edge facing the first edge along the longitudinal direction.

  On the other hand, in the coordinate input device 3B of the present embodiment, three or more light receiving means are provided at the first edge portion along the longitudinal direction of the light guide plate 10 and the longitudinal length of the light guide plate 10 is longer. The difference lies in that three or more light receiving means are also provided on the second edge facing the first edge along the direction.

  The configuration of the coordinate input device 3B according to the present embodiment will be described with reference to FIGS. FIG. 12 is a plan view showing a state in which the finger is in contact with the proximity position of the imaging unit in the coordinate input device 3A of the first embodiment. FIG. 13 is a plan view showing a problem when the finger is simultaneously brought into contact with two places in the coordinate input device 3A of the first embodiment. FIG. 14 is a perspective view showing the configuration of the coordinate input device 3B in the present embodiment. FIG. 15 is a plan view showing a lighting control method for the light source units 4A and 4B of the coordinate input device 3B. FIG. 16 is a plan view showing a detection method when the finger is brought into contact with the proximity position of the imaging unit in the coordinate input device 3B. FIG. 17 is a plan view showing a detection method when a plurality of fingers are in contact with the light guide plate in the coordinate input device 3B.

  That is, when the two imaging units 20 and 30 are provided as the light receiving means at the first edge along the longitudinal direction of the light guide plate 10, detection may be hindered as follows.

For example, as shown in FIG. 12, in the light guide plate 10, it is possible to easily detect the coordinate position of the contact position P ₁ of the finger 8 away from the imaging units 20 and 30. However, as shown in FIG. 12, the light guide plate 10, for the coordinate contact position P ₂ of the finger 8 in proximity to the imaging unit 20, 30, the angle of the viewing direction from the imaging unit 20, 30 is small 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. 13, for example, if two fingers 8A-8B are contacted simultaneously to the point _{P 1} and point _{P 2} on the surface of the light guide plate 10, the imaging unit 20, 30, two fingers 8A- There is a possibility that 8B is erroneously recognized as existing at the points P ₃ and P ₄ .

  Therefore, in the coordinate input device 3B of the present embodiment, as shown in FIG. 14, 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 portion along the longitudinal direction of the light guide plate 10, and the first edge along the longitudinal direction of the light guide plate 10 is provided. 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 locations 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 device 3B of the present embodiment, as shown in FIG. 15, the first edge light source unit 4A and the second edge light source unit 4B are alternately turned on.

Thus, as shown in FIG. 16, the coordinate contact position P ₂ of the finger 8 in proximity to the imaging unit 20, 30, even when the angle β in the viewing direction from the imaging unit 30 is small, the center of By using the imaging unit 70, an angle β ′ in the viewing direction from the image 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 finger 8 close to the imaging units 20 and 30 is deteriorated can be solved.

Further, as shown in FIG. 17, the case where two fingers 8A · 8B on the surface of the light guide plate 10 is contacted simultaneously at the point P ₁ and point P _2, the two fingers 8A · 8B by using the imaging unit 60 obtaining the viewing angle to the point _{P 1} and point _{P 2.} As a result, when using the imaging unit 20 and the imaging unit 60, apart from the points P ₁ and the point P _2, a possibility that two fingers 8A · 8B is provided and the point P ₅ and the point P ₆ is detected Is done. In this case, the points P ₁ and P ₂ obtained by the imaging units 20 and 30 shown in FIG. 13 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 fingers 8 A, 8 B, the points P ₁ and P ₂ that are the contact positions of the two fingers 8 A, 8 B on the light guide plate 10 are obtained. Can be obtained accurately. In this method, generally, if N + 1 light receiving means exist 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, so that the five points of the finger 8 can be simultaneously controlled. Detection is possible.

  As described above, in the coordinate input device 3B according to the present embodiment, the first and second edges of the light guide plate 10 each have at least three imaging units 20, 60, and 30 as light receiving means. In addition, imaging units 40, 70 and 50 are provided.

  As a result, it is possible to prevent a decrease in detection accuracy of the contact position of the finger 8 that is close to the imaging units 20 and 30 or the imaging units 40 and 50. Further, the contact position of each finger 8 can be accurately detected even in simultaneous contact of a plurality of fingers 8.

  As described above, in the coordinate input device 3A of the present embodiment, the imaging units 20 and 30 and the light source unit 4A are provided on one first edge along the longitudinal direction of the light guide plate 10, and the imaging units 40 and 50 are provided. And the light source unit 4B is provided in the other 2nd edge part which opposes the 1st edge part along a longitudinal direction, respectively.

  Moreover, the coordinate detection method of this Embodiment is a coordinate detection method using the coordinate input device 3B of this Embodiment, Comprising: The period when the light source unit 4A of the 1st edge part in the light-guide plate 10 is lighting. The coordinates of the contact position of the finger 8A on the surface of the light guide plate 10 are detected by the imaging units 20, 30 and 60 provided on the first edge portion, while the light source of the second edge portion of the light guide plate 10 is detected. During the period when the unit 4B is lit, the coordinates of the contact position of the finger 8 on the surface of the light guide plate 10 are detected by the imaging units 40, 50 and 70 provided at the second edge.

  Thereby, in the optical coordinate input device 3B using the light guide plate 10, the coordinate input device 3B and the coordinate detection method capable of detecting the coordinate positions of the plurality of fingers 8 can be provided.

  In the coordinate input device 3A of the present embodiment, the planar light guide plate 10 has a rectangular planar shape, and the imaging units 20, 30, 60, 40, 50, 70 and the light source units 4A, 4B. Is provided at the edge of the light guide plate 10 on the long side.

  That is, in the present embodiment, when a detection target such as the finger 8 is brought into contact with the light guide plate 10, the scattered light is detected by the imaging units 20, 30, 60, 40, 50, and 70. For this reason, the detection intensity in the imaging units 20, 30, 60, 40, 50, and 70 increases as the amount of scattered light increases, and the detection becomes easier. For that purpose, it is necessary to increase the light amount density of the irradiation region to the light guide plate 10 material in the light source units 4A and 4B.

  Therefore, in this embodiment, since the light guide plate 10 has a rectangular planar shape, the imaging units 20, 30, 60, 40, 50, 70 and the light source units 4A, 4B are connected to the long side of the light guide plate 10. It is provided on the side edge. Thereby, since the distance from the light source units 4A and 4B to the opposite end portion of the light guide plate 10 is reduced, the light amount density of the irradiation region to the light guide plate 10 in the light source units 4A and 4B can be increased.

  The coordinate input system 1 according to the present embodiment is a coordinate input system including the coordinate input device 3B according to the present embodiment, and includes a liquid crystal display module 2.

  According to this configuration, the coordinate input device 3 </ b> B can function as a touch panel that inputs with a detection object such as the finger 8 while viewing the image of the liquid crystal display module 2. Therefore, in the optical coordinate input device 3B that uses the light guide plate 10, even when applied to a large touch panel, the coordinate input system including the coordinate input device 3B that can detect the coordinate position of the detection target such as the finger 8 or the like. 1 can be provided.

  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 obtained by appropriately combining the technical means disclosed in each embodiment. Such embodiments are also included in the technical scope of the present invention.

  The present invention relates to a plate-shaped light guide member, a light source that makes light incident on the light guide member, at least two light receiving means, and the contact based on the contact when the object to be detected contacts the surface of the light guide member. Coordinate input device and coordinate input provided with detection means for detecting the coordinates of the position of contact of the light guide member with the surface of the light guide member based on the output of the light receiving means that has detected the propagation light inside the light guide member Can be applied to the system. Further, the coordinate input device can be applied to both a finger type and a touch pen type. Furthermore, the coordinate input system can be applied to a personal computer, a television, a white board, a tablet terminal, and the like.

1 Coordinate input system 2 Liquid crystal display module (image display module)
2a Liquid crystal display panel 3A Coordinate input device 3B Coordinate input device 4A Light source unit (light source)
4B Light source unit (light source)
4a LED
5 Optical coupling member 6 Detection part (detection means)
7 Light Absorbing Member 8 Finger (Detected Object)
8A finger (first detected object)
8B finger (second object to be detected)
10 Light guide plate (light guide member)
11 Through-hole 11a Wall surface 13a Propagating light 14a Propagating light 20 Imaging unit (light receiving means)
21 Lens 22 Optical filter 23 Imaging device 30 Imaging unit (light receiving means)
31 Lens 32 Optical filter 33 Imaging device 40 Imaging unit (light receiving means)
50 Imaging unit (light receiving means)
60 Imaging unit (light receiving means)
70 Imaging unit (light receiving means)
L interval

Claims (5)

A plate-shaped light guide member, a light source for allowing light to enter the light guide member, at least two light receiving means, and the light guide member based on the contact when the object to be detected contacts the surface of the light guide member. A coordinate input device including detection means for detecting the coordinates of the position of contact of the light guide member on the surface of the detected object based on the output of the light receiving means that detects internal propagation light,
The coordinate input device, wherein the light receiving means and the light source are provided on a back surface of the light guide member. The plate-shaped light guide member has a rectangular planar shape,
The coordinate input device according to claim 1, wherein the light receiving unit and the light source are provided on a first edge and a second edge facing each other in the light guide member.   The coordinate input device according to claim 1, wherein the light source is provided in a linear shape.   The coordinate input according to claim 2, wherein a light absorbing member is provided on at least a first light guide member surface and a light guide member rear surface at the first edge and the second edge of the light guide member. apparatus. A coordinate input system comprising the coordinate input device according to any one of claims 1 to 4,
A coordinate input system comprising an image display module.

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