WO2013111447A1

WO2013111447A1 - Coordinate input device and coordinate input system

Info

Publication number: WO2013111447A1
Application number: PCT/JP2012/080855
Authority: WO
Inventors: 岡田　訓明; 謙一郎三上; 藤原　恒夫; 直樹芝
Original assignee: シャープ株式会社
Priority date: 2012-01-27
Filing date: 2012-11-29
Publication date: 2013-08-01
Also published as: JP2013175142A

Abstract

Provided are a coordinate input device and a coordinate input system with which, when simultaneously using a plurality of bodies to be detected, identification of each of the bodies to be detected is easily and reliably carried out without being affected by the respective bodies to be detected, and cost increases are avoided. A light emitting part of each touch pen (40A, 40B) inputs into a light guide plate (10), by making contact with the surface of the light guide plate (10), either a first propagation light (L1) or a second propagation light (L2) with respectively differing wavelengths. Notches (11, 11), through which either the first propagation light (L1) or the second propagation light (L2) is discharged linearly to at least two image capture elements (23, 33) respectively, are disposed in the light guide plate (10). Between the light paths from the light guide plate (10) and each of the image capture elements (23, 33), a first filter (F1) which corresponds to the wavelength of the first propagation light (L1) and a second filter (F2) which corresponds to the wavelength of the second propagation light (L2) are arrayed to traverse the respective discharge lights which are linearly discharged.

Description

Coordinate input device and coordinate input system

The present invention relates to an optical coordinate input device and a coordinate input system using a detected object such as a finger or a stick-shaped operation member pen such as a touch pen and a stylus pen, and more specifically, a plurality of detected objects. It relates to identification when using the body simultaneously.

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 An 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 above 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 bringing the pen or finger close to or in contact with 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. 17A and 17B, the position detection device 100 disclosed in Patent Document 1 includes a light guide plate 101 made of a translucent material, and X and Y directions from the side surface of the light guide plate 101. Each light source 102, such as a semiconductor infrared laser, in which light is incident in a plurality of rows in the direction, a lighting control unit 103 that controls lighting by sequentially scanning each light source 102, and when the light guide plate 101 is touched, A touch pen 110 for detecting a contact position. In addition, as shown in FIG. 17C, the touch pen 110 is brought into contact with the light guide plate 101 to introduce light that guides light inside the light guide plate 101, and the introduction portion 111 introduces the touch pen 110. Based on the detection unit 112 that detects light and outputs a detection signal, and the detection signal output from the detection unit 112 and the scanning position by the lighting control unit 103, the coordinate position where the touch pen 110 contacts the light guide plate 101 is calculated. A coordinate calculation unit 113, an identification signal generation unit 114, and a transmission unit 115.

In the position detection device 100, the light sources 102 are sequentially controlled to light from left to right and from bottom to top of the light guide plate 101. At this time, when the touch pen 110 is pressed against a certain position of the light guide plate 101, the introduction part 111 of the touch pen 110 is brought into close contact with the light guide plate 101, whereby the total reflection condition of the light totally reflected on the surface of the light guide plate 101 is satisfied. It collapses and is introduced into the introduction part 111. The light introduced into the introduction unit 111 is detected by the detection unit 112 and outputs a detection signal. Based on this output, the coordinate calculation unit 113 calculates the coordinates of the contact point. Specifically, the two-dimensional coordinate position on the light guide plate 101 can be calculated by calculating from which light source 102 the detected light beam is detected from the detection signal output from the detection unit 112. . The calculated two-dimensional coordinate position is generated by the identification signal generation unit 114 so that a different signal frequency is generated for each of the

touch pens

110 and 110, and is transmitted from the transmission unit 115 to a receiving device (not shown) at the signal frequency. It has become.

Thus, in the position detection device 100, two types of

touch pens

110 and 110 can be used, and the identification is performed by transmission using different signal frequencies.

Also, as an optical coordinate detection device capable of simultaneously detecting a plurality of other pens, for example, a coordinate detection device disclosed in Patent Document 2 is known.

As shown in FIG. 18A, the coordinate detection apparatus 200 includes two types of

stylus pens

210a and 210b each having a light emitting unit 211 to touch a position on the touch panel 201, and light emitting units of the

stylus pens

210a and 210b.

Detectors

231a and 232a for the stylus pen 210a that detect light emitted from the stylus pen and detect respective positions based on the triangulation method, and

detectors

231b and 232b for the stylus pen 210b. .

In the coordinate detection apparatus 200, in order to identify the two types of

stylus pens

210a and 210b, as shown in FIG. 18B, in the stylus pen 210a, the light emitting unit 211 emits red light and the detection unit 231a. -232a is provided with a red light transmission filter 221a that transmits red light and cuts blue light.

On the other hand, in the stylus pen 210b, although not shown, the light emitting unit 211 emits blue light, and the

detection units

231b and 232b transmit blue light and cut red light. Is provided.

With this configuration, two types of

stylus pens

210a and 210b can simultaneously identify and detect two coordinates.

Recently, a coordinate input device for touching a touch panel with a finger instead of a touch pen has been disclosed.

For example, as shown in FIGS. 19A and 19B, the touch panel 300 disclosed in Patent Document 3 includes a light guide plate 301, a light source 302 that makes light incident on the light guide plate 301, and a side surface of the light guide plate 301. The light from the light source 302 scattered by the detected object 310 is imaged on the

light receiving elements

304 and 305 between the

light receiving elements

304 and 305 arranged in part and the side surface of the light guide plate 301 and the

light receiving elements

304 and 305. And an imaging means 307. Further, light absorbing means 308 is disposed on the side surface of the light guide plate 301 on which the

light receiving elements

304 and 305 are disposed, and the

light receiving elements

304 and 305 are outside the irradiation range of the light source 302 as shown in FIG. Has been placed.

The coordinate detection principle of the touch panel 300 is as follows.

The light emitted from the light source 302 disposed on the side surface of the light guide plate 301 propagates while repeating total reflection inside the light guide plate 301. In a normal state, since the

light receiving elements

304 and 305 are arranged outside the irradiation range of the light source 302, they do not receive propagating light propagating through the light guide plate 301. Here, when the detection object 310 such as a finger is touched on the transparent light guide plate 301, the propagation light is disturbed and scattered light is generated. A part of the scattered light also propagates in the direction of the

light receiving elements

304 and 305 and is received by the

light receiving elements

304 and 305 as shown in FIG. In FIG. 20B, the vertical axis represents the signal intensity, and the horizontal axis represents the pixel numbers of the

light receiving elements

304 and 305, respectively. By specifying the pixel numbers G304 and G305 of the light receiving elements having strong signal intensities shown as I304 and I305, the azimuth angle is measured, and the point where the scattered light is generated by the triangulation method, that is, the detected object such as a finger The point where 310 is touched is specified.

JP 2008-158616 A (published July 10, 2008) JP 2003-256123 A (published on September 10, 2003) JP 2009-258967 A (published on November 5, 2009)

However, the conventional coordinate input device and coordinate input system have the following problems.

That is, when using a plurality of pens, the position detection apparatus 100 of the method disclosed in Patent Document 1 identifies the two types of

touch pens

110 and 110 by transmitting at different signal frequencies. There is no problem with the interference. However, since a plurality of light sources corresponding to each coordinate and a plurality of light receiving units that receive light from the light sources are required on the two side surfaces of the light guide plate 101, the cost of the light sources and the light receiving units is increased.

On the other hand, in the coordinate detection apparatus 200 that uses the triangulation method for coordinate calculation disclosed in Patent Document 2, each light emitted from the pen tips of a plurality of pens that emit light of different wavelengths propagates in space. An optical filter is provided in front of the imaging device that images the propagation light, and each imaging device calculates the incident angle of the propagation light by imaging light of a single wavelength. Find the coordinate position of. However, when two pens are lined up in the line-of-sight direction of the image sensor, light emitted from a pen located behind the image sensor is blocked by a pen in front or a finger / hand holding the pen. The position cannot be detected.

In order to prevent this, the coordinate detection apparatus 200 includes two types of detection units: a pair of

detection units

231a and 232a for the stylus pen 210a and a pair of

detection units

231b and 232b for the stylus pen 210b. Provided. Each of the

detection units

231a and 232a and the

detection units

231b and 232b is provided with a different light transmission film in front of a detector such as a CCD. Moreover, when it is blocked by a pen in front or a finger / hand holding a pen, it is dealt with by performing an interpolation process.

As a result, in the coordinate detection device 200 disclosed in Patent Document 2, in order to use the two types of

stylus pens

210a and 210b, it is necessary to provide two types of detectors and a total of four detectors. Further, since interpolation processing is required, there is a problem that position detection is complicated and inaccurate, and costs are increased.

Also, with the touch panel 300 disclosed in Patent Document 3, a pen and a finger cannot be used simultaneously.

The present invention has been made in view of the above-described conventional problems, and its object is to use each detected object without being affected by each other detected object when a plurality of detected objects are used simultaneously. It is an object of the present invention to provide a coordinate input device and a coordinate input system that perform simple and reliable identification and avoid an increase in cost.

In order to solve the above problems, a coordinate input device according to the present invention includes a plate-shaped light guide member, at least two light receiving portions that receive propagating light propagating through the light guide member, and a surface of the light guide member. Detecting means for obtaining coordinates of a contact position on the surface of the light guide member in the detected body based on an output of the light receiving unit that detects propagation light based on the contact when the detected body is contacted In the coordinate input device, the detection object includes at least two first detection objects and a second detection object, and the first propagation light based on the contact of the first detection object and the above detection object The second propagating light based on the contact of the second object to be detected has a wavelength different from that of the second propagating light, and the light guide member linearly transmits the first propagating light or the second propagating light to the two light receiving portions. An optical path changing unit that emits light is provided, and the light guide member and each light receiving member The first filter corresponding to the wavelength of the first propagating light and the second filter corresponding to the wavelength of the second propagating light are emitted in the linear form, and It is characterized by being arranged side by side so as to traverse the outgoing light of the second propagation light.

According to the above invention, the coordinate input device includes a plate-shaped light guide member, at least two light receiving portions that receive propagating light propagating through the light guide member, and a detected object on the surface of the light guide member. Detecting means for obtaining coordinates of a contact position of the detected body with respect to the surface of the light guide member based on an output of the light receiving unit that detects propagation light based on the contact.

In such a coordinate input device, when a plurality of detection objects are used at the same time and light in the same wavelength region is used for detection of each detection object, the detection objects are in the line-of-sight direction of the light receiving unit. When two of them are arranged, the image of the detected object located in the back as viewed from the light receiving unit and the image of the detected object in the front overlap each other, which causes a problem that the position cannot be detected by the triangulation method.

In order to solve this problem, for example, a pair of first light receiving unit and second light receiving unit that generate light of different wavelengths for two detected objects and are indispensable for each detected object. If two sets are prepared, the number of parts of the apparatus increases and the cost increases.

Therefore, in the present invention, first, even when two or more objects to be detected are used at the same time, the light receiving unit is provided with only at least one pair of the first light receiving unit and the second light receiving unit that are essential in the triangulation method. Not. And in order to identify each to-be-detected body in a 1st light-receiving part and a 2nd light-receiving part, it has the following structures.

First, the first propagation light based on the contact of the first detection object and the second propagation light based on the contact of the second detection object have different wavelengths. Next, the light guide member is provided with an optical path conversion unit that emits the first propagation light or the second propagation light to the two light receiving units in a linear manner. In addition, a first filter corresponding to the wavelength of the first propagation light and a second filter corresponding to the wavelength of the second propagation light are emitted linearly between the optical paths of the light guide member and each light receiving unit. The first propagation light and the emission light of the second propagation light are arranged side by side so as to cross each other.

Thereby, for example, the emitted light of the first propagation light based on the contact of the first detection object is emitted linearly to the two light receiving units through the optical path changing unit and the first filter. Similarly, the emitted light of the second propagation light based on the contact of the second detection object is also emitted linearly to the two light receiving parts via the optical path changing part and the second filter, respectively. Here, the 1st filter and the 2nd filter are arranged side by side so that the outgoing light of the 1st propagation light and the 2nd propagation light emitted in the shape of a line may be crossed, respectively.

For this reason, two images of a linear image of the outgoing light of the first propagation light and a linear image of the outgoing light of the second propagation light appear as parallel lines in the light receiving unit. The two lines appear in a staggered manner corresponding to the passage of the first filter and the second filter.

As a result, if two first detection bodies and two second detection bodies are arranged in the line-of-sight direction of one light receiving section, the first detection body is positioned in front of the light receiving section in the light receiving section. The first propagating light based on the contact and the first propagating light based on the contact of the second detected object located in the back as viewed from the light receiving unit are respectively divided into the same line on the same line. appear.

Therefore, in each light receiving part, one side and both angles between the light receiving parts in the first detected object and the second detected object can be obtained, and the first detected object and the second detected object are obtained by triangulation. The plane coordinates of the position on the light guide member in contact with the detection target can be detected. When there are three detected bodies, the third filter is disposed on the first filter and the second filter, and the third propagation light based on the contact of the third detected body is further emitted. Since the incident light also crosses the third filter, similarly, the contact position of the third detected object can be easily measured. The same applies even when there are four or more detected objects.

In the present invention, the first propagating light based on the contact of the first detected body and the second propagating light based on the contact of the second detected body do not use the air above the light guide member as an optical path. The inside of the light guide member is used as an optical path. For this reason, since the optical path of the detected object is shielded by a finger or the like having the detected object and no interpolation processing is performed to obtain the coordinate position of the detected object, detection can be performed reliably and accurately. Further, since the number of light receiving parts is not increased, each detected object can be easily identified and there is no cost increase.

Therefore, when using a plurality of detected objects at the same time, a coordinate input device is provided that can easily and reliably identify each detected object and avoid an increase in cost without being affected by each other detected object. can do.

In the coordinate input device of the present invention, the first detection body and the second detection body each have a light emitting unit that makes light of different wavelengths incident on the light guide member by contacting the surface of the light guide member. A light-emitting pen, and the light-receiving portion is incident on the light guide member from the light-emitting portions of the first detection body and the second detection body and propagates through the light guide member. Light emitted from the light guide member in the first propagation light and the second propagation light is received.

According to said invention, the 1st to-be-detected body and the 2nd to-be-detected body each have the light emission part which has a light emission part which injects light of a mutually different wavelength into this light guide member by contacting the surface of a light guide member. It is made up of.

In such a coordinate input device, when two or more light emitting pens are used at the same time and each light emitting pen uses light of the same wavelength region, two light emitting pens are arranged in the line-of-sight direction of the light receiving unit. At this time, since the light emitted from the light-emitting pen located behind the light-receiving unit is blocked by the light-emitting pen in front, there is a problem that the position cannot be detected by the triangulation method.

In order to solve this problem, for example, a pair of first light receiving portion and second light receiving portion that generate light of different wavelengths for two light emitting pens and are essential for each light emitting pen. If two sets are prepared, the number of parts of the apparatus increases and the cost increases.

Therefore, in the present invention, first, even when two or more light emitting pens that allow light to enter the light guide member are used at the same time, the light receiving unit includes at least one set of the first light receiving unit and the first light receiving unit essential for triangulation. Only the second light receiving part is provided. And in order to identify the light emission from each light emission pen in a 1st light-receiving part and a 2nd light-receiving part, it has the following structures.

First, the light emitting portion of each light emitting pen makes light of a different wavelength enter the light guide member by contacting the surface of the light guide member. Next, an optical path changing unit that emits the first propagating light or the second propagating light that is incident from each light-emitting pen and guides the inside of the light guiding member to the two light receiving units, respectively, in a linear shape. Is provided. In addition, a first filter corresponding to the wavelength of the first propagation light and a second filter corresponding to the wavelength of the second propagation light are emitted linearly between the optical paths of the light guide member and each light receiving unit. The first propagation light and the emission light of the second propagation light are arranged side by side so as to cross each other.

Thereby, for example, the emitted light of the first propagation light emitted from one light-emitting pen and guided through the light guide member is linearly transmitted to the two light receiving units via the optical path conversion unit and the first filter. Respectively. Similarly, the emitted light of the second propagating light emitted from the other light-emitting pen and guided through the light guide member is linearly connected to the two light receiving units via the optical path changing unit and the second filter. Respectively. Here, the 1st filter and the 2nd filter are arranged side by side so that the outgoing light of the 1st propagation light and the 2nd propagation light emitted in the shape of a line may be crossed, respectively.

As a result, if two light emitting pens are arranged in the line-of-sight direction of one light receiving unit, the light receiving unit receives light emitted from one light emitting pen located in front of the light receiving unit, and from the light receiving unit. Lights emitted from other light-emitting pens that are located at the back of the screen appear simultaneously and on the same line as divided lines.

Therefore, one light-emitting pen and another light-emitting pen in each light-receiving unit can determine one side and both angles between the light-receiving units, and triangulation method can be used in one light-emitting pen and another light-emitting pen. The plane coordinates of the position on the light guide member in contact with the light-emitting pen can be detected. If there are three light-emitting pens, the third filter is disposed on the first filter and the second filter, and the light emitted from other light-emitting pens crosses the third filter. In addition, the contact position of another light-emitting pen can be easily measured. The same applies even when there are four or more light emitting pens.

Further, in the present invention, the light emitted from the light emitting unit from the light emitting pen does not use the air above the light guide member as an optical path, but uses the inside of the light guide member as an optical path. For this reason, since the light path of the light-emitting pen is shielded by a finger or the like having the light-emitting pen and no interpolation processing is performed to obtain the coordinate position of the light-emitting pen, detection can be performed reliably and accurately. Furthermore, since the number of light receiving parts is not increased, each light emitting pen is easily identified, and there is no increase in cost.

Therefore, when using a plurality of light-emitting pens simultaneously, each light-emitting pen is easily, reliably, and accurately identified without being affected by each other's light-emitting pens or fingers operating the light-emitting pen, thereby increasing costs. A coordinate input device to avoid can be provided.

In the coordinate input device of the present invention, it is preferable that a light scattering member for allowing diffused light to enter the light guide member is provided at the tip of each light emitting pen.

Thereby, when the light emitted from the light emitting portion of each light emitting pen is incident on the light guide member, the diffused light can be incident on the light scattering member. As a result, light is guided radially from the contact position of each light-emitting pen to the light guide member inside the light guide member, and a sufficient amount of received light can be obtained in any light receiving part.

In the coordinate input device of the present invention, the intensity of the light emitted from the light emitting unit of each light emitting pen is adjusted so that each detection sensitivity becomes the same according to the light receiving sensitivity in the wavelength region of the light receiving unit. Preferably it is.

That is, for example, in a light receiving part of a CMOS (Complementary Metal Oxide Semiconductor) camera or the like, the light receiving sensitivity tends to decrease as it goes to the long wavelength side. For this reason, a short wavelength signal may be detected strongly. In this regard, in the present invention, the intensity of the light emitted from the light emitting unit of each light emitting pen is adjusted so that the respective detection sensitivities are the same according to the light receiving sensitivity in the wavelength region of the light receiving unit. As a result, it is possible to avoid the strong detection of a signal having a specific wavelength and to make the detection sensitivity uniform.

In the coordinate input device of the present invention, the wavelength of the light emitted from the light emitting unit of each light emitting pen is such that the interval between the peak wavelengths of each light is farther than the peak half-value width in the light having the larger peak width. Thus, it is preferable that they are different from each other.

That is, there is a possibility that light having a wide peak half width cannot be completely wavelength-separated even if an optical filter is used. For this reason, in order to perform complete separation detection, it is necessary to select a wavelength in consideration of the half-value width of the light peak. In this regard, in the present invention, the wavelength of the light emitted from the light emitting portion of each light emitting pen is such that the interval between the peak wavelengths of each light is separated from the peak half-value width in the light having the larger peak width. Are different from each other. As a result, the wavelength of each light emitted from the light emitting unit of each pen can be sufficiently separated and identified.

In the coordinate input device of the present invention, a light source that allows illumination light to enter from an end portion of the light guide member is provided, and the first detected body contacts the surface of the light guide member, whereby the light guide member has a light source. The second detected body is made of a light emitting pen having a light emitting part that makes light having a wavelength different from that of the illumination light incident upon contact with the surface of the light guide member. The light receiving unit is illumination light propagating in the light guide member and the first propagating light that is the scattered light by the first detected body and the light from the light emitting unit by the second detected body. And receiving the second propagating light and detecting the change in the output intensity of the light receiving unit based on the scattering of the illumination light due to the contact of the first detected body with the light guide member. 1 The position of contact with the surface of the light guide member in the detected body The coordinates of the contact position of the second detected body with respect to the surface of the light guide member based on the output of the light receiving unit that receives the second propagation light due to the contact of the second detected body with the light guide member It is characterized by seeking.

According to the above invention, the first detected body scatters the illumination light propagating through the light guide member by contacting the surface of the light guide member, while the second detected body is the light guide member. It comprises a light-emitting pen having a light-emitting portion that makes light having a wavelength different from that of the illumination light incident upon contact with the surface of the light.

That is, in the present invention, the second object to be detected is composed of a light-emitting pen having a light-emitting portion that makes light incident upon contact with the surface of the light guide member. For this reason, the coordinates of the contact position of the light-emitting pen can be obtained based on the detection principle of the light-emitting pen described above. Specifically, the light receiving unit receives the second propagation light that is light from the light emitting unit by the second detection target. The detecting means detects the position of the contact of the second detected body with the surface of the light guide member based on the output of the light receiving unit that receives the second propagation light due to the contact of the second detected body with the light guiding member. Find the coordinates.

On the other hand, the first detected body scatters the illumination light propagating through the light guide member by coming into contact with the surface of the light guide member, and corresponds to a detected body such as a finger.

In order to detect a detection object such as a finger that does not emit such light by the light receiving unit, it is necessary to make illumination light incident from the end of the light guide member in advance. Therefore, in the present invention, a light source for making illumination light incident from the end of the light guide member is provided.

In such a coordinate input device, the light receiving unit receives the illumination light propagating in the light guide member and the first propagation light which is the scattered light from the first detected body. The detecting means detects a change in the output intensity of the light receiving unit based on the scattering of the illumination light due to the contact of the first detected body with the light guiding member, and moves to the surface of the light guiding member in the first detected body. Find the coordinates of the contact position.

Thereby, the contact position of the first detected body made of a finger or the like to the light guide member can be obtained.

Here, in the touch panel of Patent Document 3, in the state where the amount of light received by the light receiving unit is maintained at 0, the light reception peak of the scattered light due to the presence of the detection target is detected. As a result, since the amount of scattered light received by the detected object is very small, the signal quality deteriorates in contact detection of the detected object far from the light receiving hand, and it is difficult to apply to a large touch panel. Had a point.

In this regard, in the present invention, the idea is changed with respect to Patent Document 3, and in Patent Document 3, the light receiving peak of scattered light due to the presence of the detected object is detected, whereas in the present invention, the light receiving means is used. In a state where a certain amount of received light is given, a change in output intensity at the light receiving unit is detected based on light scattering due to the presence of the detection target.

As a result, a constant amount of received light is constantly given to the light receiving portion, and in that state, the intensity of the constant amount of received light decreases due to light scattering caused by contact of the detection object at a distance from the light receiving portion. For this reason, by detecting this decrease in strength, the coordinates of the contact position of the detected body on the surface of the light guide member can be obtained by the detecting means.

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.

By the way, in such a coordinate input device, the first detected body made of a finger or the like and the second detected body made of a light emitting pen are used at the same time, and the first detected body and the second detected body are detected. When light of the same wavelength region is used, when the first detection object and the second detection object are arranged in the line-of-sight direction of the light receiving unit, the image of the detection object located in the back as viewed from the light receiving unit And the image of the object to be detected in front of each other overlap, so that there is a problem that the position cannot be detected by the triangulation method.

In order to solve this problem, for example, light having different wavelengths is used for the two first detection objects and the second detection object, and the first detection object and the second detection object are used. Providing two essential pairs of the first light receiving part and the second light receiving part increases the number of parts of the apparatus and increases the cost.

Therefore, in the present invention, even when the first detected body and the second detected body are used at the same time, first, the light receiving section is at least one set of the first light receiving section and the second light receiving section essential in the triangulation method. It is only provided. And in order to identify a 1st to-be-detected body and a 2nd to-be-detected body in a 1st light-receiving part and a 2nd light-receiving part, it has the following structures.

First, the second object to be detected is composed of a light-emitting pen having a light-emitting portion that makes light having a wavelength different from the illumination light from the light source incident upon contact with the surface of the light guide member. Next, a first filter corresponding to the wavelength of the first propagation light and a second filter corresponding to the wavelength of the second propagation light are disposed between the optical paths between the light guide member and each of the light receiving units. Are arranged side by side so as to cross the emitted light of the first propagation light and the second propagation light emitted in a shape.

Thereby, for example, the emitted light of the first propagation light based on the contact of the first detection object is emitted linearly to the two light receiving units through the optical path changing unit and the first filter. Similarly, the emitted light of the second propagation light based on the contact of the second detection object is also emitted linearly to the two light receiving parts via the optical path changing part and the second filter, respectively.

Here, the first filter and the second filter are arranged side by side so as to cross the emitted light of the first propagation light and the second propagation light, which are emitted linearly. For this reason, for example, when the boundary between the first filter and the second filter is a straight line, the light receiving unit has a linear image of the emitted light of the first propagation light and the emitted light of the second propagation light. Two images with a linear image appear as parallel lines. The two lines appear in a staggered manner corresponding to the passage of the first filter and the second filter. When the boundary between the first filter and the second filter is not a straight line but an arc, each image appears as an image of a line radially extending around the center of the fan shape.

As a result, if the first detected body and the second detected body are arranged in the line-of-sight direction of one light receiving section, the light receiving section of the first detected body positioned in front of the light receiving section The first propagating light based on the contact and the second propagating light based on the contact of the second detected object located in the back as viewed from the light receiving unit appear as divided lines on the same line at the same time. .

In the coordinate input device of the present invention, the intensity of each light emitted from the light source and the light emitting part of the second detected object has the same detection sensitivity according to the light receiving sensitivity in the wavelength region of the light receiving part. It is preferable that the adjustment is performed.

That is, for example, in a light receiving part of a CMOS (Complementary Metal Oxide Semiconductor) camera or the like, the light receiving sensitivity tends to decrease as it goes to the long wavelength side. For this reason, a short wavelength signal may be detected strongly. In this regard, in the present invention, the intensity of each light emitted from the light source and the light emitting part of the second object to be detected is equal to each other depending on the light receiving sensitivity in the wavelength region of the light receiving part. It has been adjusted. As a result, it is possible to avoid the strong detection of a signal having a specific wavelength and to make the detection sensitivity uniform.

In the coordinate input device of the present invention, the wavelength of each light emitted from the light source and the light emitting part of the second detected object is the peak half-value width in the light having the larger peak width in the interval between the peak wavelengths of each light. It is preferred that they are different from each other so that they are farther apart.

That is, there is a possibility that light having a wide peak half width cannot be completely wavelength-separated even if an optical filter is used. For this reason, in order to perform complete separation detection, it is necessary to select a wavelength in consideration of the half-value width of the light peak. In this regard, in the present invention, the wavelength of each light emitted from the light source and the light emitting part of the second detection object is such that the interval between the peak wavelengths of each light is larger than the peak half-value width in the light having the larger peak width. As they are apart, they are different from each other. As a result, the wavelength of each light emitted from the light source and the light emitting part of the second detected object can be sufficiently separated and identified.

In the coordinate input device of the present invention, it is preferable that the first filter and the second filter are provided continuously and integrally.

Thereby, since the images at the light receiving portions of the plurality of detection objects are not shifted, the coordinate position detection accuracy can be improved.

In the coordinate input device of the present invention, it is preferable that the boundary between the first filter and the second filter is an arc.

Thereby, since the shape of the optical path conversion part provided in the light guide member can be made into a shape in which the corner part of the light guide member is cut obliquely with a conical surface or a hyperboloid, the optical path conversion part can be easily formed. Can be formed.

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 is characterized by including an image display panel.

According to the above invention, the coordinate input device can function as a touch panel for pen input and finger input while viewing an image on the image display panel. Therefore, for example, when a plurality of light-emitting pens and fingers are used, coordinates that easily and reliably identify each light-emitting pen and finger without being affected by the light-emitting pens and fingers and avoid an increase in cost. A coordinate input system including an input device can be provided.

As described above, in the coordinate input device of the present invention, the detection target includes at least two first detection target and second detection target, and the first detection target is based on the contact of the first detection target. The propagating light and the second propagating light based on the contact of the second object to be detected have different wavelengths, and the light guide member transmits the first propagating light or the second propagating light to the two light receiving portions. An optical path conversion unit that emits in a linear shape is provided, and a first filter corresponding to the wavelength of the first propagation light and the second propagation light are disposed between the light paths of the light guide member and the light reception units. The second filter corresponding to the wavelength is arranged side by side so as to cross the outgoing light of the first propagation light and the second propagation light emitted in the above-described linear shape.

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 panel.

Therefore, when using a plurality of objects to be detected at the same time, the coordinate input device can easily and reliably identify each object to be detected without being affected by each other object to be detected, and avoid an increase in cost. And there is an effect that a coordinate input system is provided.

(A) shows one Embodiment of the coordinate input device in this invention, Comprising: It is a perspective view which shows the structure of a coordinate input device, (b) is a top view which shows the structure of the filter of the said coordinate input device. It is. It is a perspective view which shows the whole structure of the coordinate input system provided with the said coordinate input device. FIG. 3 shows an overall configuration of the coordinate input system, and is a cross-sectional view taken along line AA in FIG. 2. It is a top view which removes and shows the housing | casing of the upper surface in the touch pen of the said coordinate input device. It is sectional drawing which shows the structure of the light-scattering member provided in the front-end | tip of the said touch pen. (A) is a perspective view which shows the imaging condition in the imaging unit in the said pen input device, (b) is a top view which shows the image in the imaging device of the said imaging unit. It is a chart which shows the separation distance of the peak wavelength of each light light-emitted from two touch pens. It is a chart which shows the sensitivity wavelength dependence of the said image pick-up element. It is a top view which shows the structure of the modification in the filter of the said coordinate input device. FIG. 7 is a perspective view showing an overall configuration of a coordinate input system including a coordinate input device according to another embodiment of the coordinate input device and the coordinate input system of the present invention. FIG. 11 shows an overall configuration of the coordinate input system, and is a cross-sectional view taken along line BB in FIG. 10. (A) is a top view which shows the output image of an image pick-up element when a finger is not contacting the light guide plate, (b) is a top view which shows the output image of an image pick-up element when a finger is contacted to the light guide plate It is. (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. (A) is a perspective view which shows the whole structure at the time of using a finger and a touch pen together simultaneously in the said coordinate input device, (b) is an output of an image pick-up element when a finger and a touch pen are contacted with the light-guide plate. It is a top view which shows an image. FIG. 10 is a perspective view showing an overall configuration of a coordinate input device according to another embodiment of the coordinate input device of the present invention. The modification of the said coordinate input device is shown, Comprising: It is a top view which shows the whole structure of a coordinate input device. (A) is a top view which shows the structure of the position detection apparatus as a conventional coordinate input device, (b) is sectional drawing which shows the structure of the said position detection apparatus, (c) is the housing | casing of the upper surface in a touch pen It is a top view which removes and shows. (A) is a top view which shows the structure of the coordinate detection apparatus as another conventional coordinate input device, (b) is sectional drawing which shows the structure of the said coordinate detection apparatus. (A) is a perspective view which shows the structure of the position detection apparatus as another 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 said conventional position detection apparatus, (b) is a wave form diagram which shows the optical signal of the light receiving element in the said position detection apparatus.

[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 FIG. FIG. 2 is a perspective view showing the configuration of the coordinate input system.

As shown in FIG. 2, the coordinate input system 1 of the present embodiment includes a liquid crystal display panel 2 as an image display panel, and a pen input device 3A as a coordinate input device provided on the upper side of the liquid crystal display panel 2. It has.

The liquid crystal display panel 2 has a liquid crystal layer sandwiched between a pair of substrates (not shown), and each substrate is provided with at least various electrodes for changing the orientation of liquid crystal molecules of the liquid crystal layer by applying a voltage. . Then, by changing the orientation of the liquid crystal molecules by applying a voltage, the amount of light transmitted through the liquid crystal layer of each pixel is adjusted to perform a desired display. As the configuration of the liquid crystal display panel 2, a conventionally known liquid crystal display panel can be used.

In the coordinate input system 1, while looking at the screen displayed on the liquid crystal display panel 2, a pen and a touch pen as a detection object are placed on a light guide plate 10 described later of a pen input device 3 A provided on the upper side of the liquid crystal display panel 2. By touching 40, the coordinates of the contact position on the touch pen 40 are specified, and desired data can be input.

(Configuration of pen input device)
Next, the configuration of the pen input device 3A provided in the coordinate input system 1 will be described in detail below based on FIG. 2 and FIG. 3 is a cross-sectional view taken along line AA in FIG.

As shown in FIG. 2, the pen input device 3A includes a light guide plate 10 as a rectangular transparent light guide member,

imaging units

20 and 30 disposed at both ends of one side of the light guide plate 10, and a light guide plate. 10 and a touch pen 40 as a light emitting pen.

The light guide plate 10 is made of a single flat plate made of a translucent material, and is disposed so as to overlap the display surface side of the liquid crystal display panel 2. The size of the light guide plate 10 is a quadrangle having substantially the same size as the liquid crystal display panel. Specifically, as shown in FIG. 2, one side where the

imaging units

20 and 30 are disposed is configured to be larger than the liquid crystal display panel 2. Accordingly, at least a part of the

imaging units

20 and 30 can be disposed on the back side of the light guide plate 10. As a result, an increase in size of the pen input device 3A in the direction of spreading along the contact surface to the light guide plate 10 in the touch pen 40 is suppressed, contributing to the realization of a compact size of the pen input device 3A.

Further, notches 11 as concave conical surface optical path conversion portions are formed at two corners of the light guide plate 10 where the

imaging units

20 and 30 are disposed, respectively. The angle (γ shown in FIG. 3) formed by the conical surface of the notch 11 and the back surface of the light guide plate 10 is 45 degrees or less, and 30 degrees or 45 degrees is selected. The conical notch 11 is provided with a mirror coating 11a. As a result, as shown in FIG. 3, the optical path of light propagating through the inside of the light guide plate 10 to the notch 11 is changed by the notch 11 below the light guide plate 10, that is, toward the back surface of the light guide plate 10. Let Even without the mirror coating 11 a, the optical path can be changed below the light guide plate 10 by the conical surface of the notch 11. That is, the light guide plate 10 does not have to be a perfect quadrangle, and may be a substantial quadrangle such that corners are notched or corners are curved as described above.

In the present embodiment, since the light conversion member is provided as the notch 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.

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, for example, 2 mm. As a material of the light guide plate 10, for example, acrylic is used, and polycarbonate or glass may be used. Further, the size of the quadrilateral of the light guide plate 10 can be, for example, about 1 m square, but is not limited thereto.

The

imaging units

20 and 30 are disposed immediately below the conical cutout 11 in the light guide plate 10. In other words, the

imaging units

20 and 30 are disposed at two locations separated from each other at the end of the light guide plate 10. In addition, the

imaging units

20 and 30 do not protrude above the surface of the light guide plate 10.

The imaging unit 20 includes a lens 21, a filter 22, and an imaging element 23 as a light receiving unit. Similarly, the imaging unit 30 includes a lens 31, a filter 32, and an imaging element 33 as a light receiving unit. The light receiving surfaces of the

image sensors

23 and 33 are arranged so as to be parallel to the surface of the light guide plate 10. The

image sensors

23 and 33 are two-dimensional image sensors.

The

imaging units

20 and 30 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 and 33.

In the present embodiment, the notch 11 is configured in a conical surface shape, but the present invention is not limited to this, and may be configured in a polygonal surface shape.

(Configuration of touch pen)
Next, the structure of the touch pen of this Embodiment is demonstrated based on FIG.4 and FIG.5. FIG. 4 is a plan view showing the configuration of the touch pen 40 of the present embodiment. In FIG. 4, for convenience of explanation, a part of the housing is removed to expose the internal structure. FIG. 5 is a cross-sectional view showing the configuration of the light scattering member provided at the tip of the touch pen.

The touch pen 40 is an operation member called a so-called touch pen or stylus pen.

As shown in FIG. 4, the touch pen 40 introduces light emitted from the light emitting element 42 a into the light guide plate 10 through the light emitting element 42 a that emits light and the light emitted from the light emitting element 42 a into the outer casing 41. The light-emitting part 42 which has the introduction part 42b to make, the power supply device 43, and the control apparatus 44 are stored. A light scattering member 45 that diffuses light is fixedly attached to the introduction portion 42b on the light emitting tip side of the touch pen 40.

The light scattering member 45 is made of a resin containing a light diffusing material. Glass beads can be used as the light diffusion material. Moreover, as said resin, fluororesins, such as polytetrafluoroethylene, or a silicon rubber can be used, for example, and it is preferable to have elasticity. By using the elastic material, when the tip of the touch pen 40, that is, the light scattering member 45 is used in contact with the light guide plate 10 of the pen input device 3A, the surface of the light guide plate 10 is not damaged, and the contact portion is slightly touched by the contact. Can be deformed to increase the contact area with the surface of the light guide plate 10. As a result, as shown in FIG. 5, the amount of light introduced to the surface of the light guide plate 10 can be increased. That is, light from the touch pen 40 can be incident in a plurality of radial directions with respect to the depth direction inside the light guide plate 10.

The light exit surface of the light scattering member 45 has a curved surface as shown in FIG. That is, the light scattering member 45 is generally hemispherical and has a diameter of, for example, 2.5 to 5.5 mm. When the diameter is smaller than 2.5, there is a possibility that the sufficiently diffused light cannot be formed. Further, when the light scattering member 45 is used in contact with the light guide plate 10 of the pen input device 3A, there is a possibility that light that can ensure a sufficient contact area is not sufficiently introduced into the surface of the light guide plate 10. On the other hand, when the diameter exceeds 5.5 mm, the diffused light may be excessively spread and it may be difficult to perform accurate position detection. Further, when the light scattering member 45 is brought into contact with the light guide plate 10 of the pen input device 3A, since the contact area is too large, there is a possibility that the frictional resistance becomes too large and the operability is impaired. As a result, if the diameter is 2.5 to 5.5 mm, the position coordinates can be detected with high accuracy while light can be diffused efficiently. In addition, a smooth writing taste, that is, a touch feeling can be realized. Note that the curved surface does not need to be configured with a uniform curvature, and the curvature may be different between the region that is the most distal end portion of the touch pen 40 and the region that surrounds the region.

Further, the curved surface may be provided with a fine uneven shape on the surface. Light can be diffused by this fine uneven shape. In addition, when the light scattering member 45 is used in contact with the light guide plate 10 of the pen input device 3A, the contact area with the light guide plate 10 is reduced by this fine uneven shape, and the frictional force when sliding is reduced. Therefore, a smooth writing taste, that is, a touch feeling can be realized. In addition, in the case of a mode in which a fine concavo-convex shape is provided in this way, the light scattering member 45 is constituted by a single resin without including a light diffusing material, and the fine concavo-convex shape in the region facing the light guide plate 10 in the resin. By providing the light diffusion effect, a light diffusion effect can be achieved. In other words, if a fine uneven shape is formed in addition to including the light diffusion material, the light diffusion effect can be further enhanced. The fine uneven shape can be formed by molding, but is not limited to this method. Although the contact area with the light guide plate 10 is reduced by providing a fine concavo-convex shape, the reduction in the amount of introduced light is about 5%, so that the position coordinate detection is not greatly affected.

Further, it is preferable that the light emitting surface of the light scattering member 45 is subjected to wear resistance processing. This is unnecessary when the light scattering member 45 is made of a fluororesin such as polytetrafluoroethylene, but when the light scattering member 45 itself is made of another material that is not excellent in wear resistance. It is effective to subject the light emitting surface to wear-resistant processing. Although there is no restriction | limiting in particular with an abrasion-resistant process, For example, the process which coats fluororesins, such as polytetrafluoroethylene, on the light-projection surface of the light-scattering member 45 is mentioned.

Furthermore, the light scattering member 45 is configured to be detachable from the touch pen 40. Thereby, even if the light scattering member 45 is damaged for some reason or is deteriorated with time, the use of the touch pen 40 can be continued only by replacing the light scattering member 45. Moreover, compared with the structure which replace | exchanges touch pen 40 itself, use can be continued at low cost. Further, since it is detachable, the introduction portion 42b, which is a member to which the light scattering member 45 is attached, is provided with a groove structure, an occlusal structure, or a fitting structure at a portion in contact with the light scattering member 45. On the other hand, the light scattering member 45 is preferably provided with a structure that matches the structure. In the present embodiment, the light scattering member 45 is attached to the introduction portion 42b. However, the present invention is not limited to this, and may be an aspect in which the light scattering member 45 is attached to the housing 41, or another aspect.

The light emitting element 42a may be, for example, an LED (light emitting diode) or an LD (laser diode) that emits light such as infrared light. Note that the number of LEDs or LDs is not limited to one provided for one touch pen 40, and a plurality of LEDs or LDs may be mounted.

The power supply device 43 may be configured to include a battery, for example, or may be configured to be rechargeable.

The control device 44 controls the light emission of the light emitting element 42a. For example, a mechanism that emits light only when the light emitting element 42a contacts the light guide plate 10 is included. This mechanism is configured by using a pressure-sensitive switch or the like, and can control the light emission time, thereby reducing power consumption and extending battery life.

In the touch pen 40 configured as described above, the light emitting element 42a that receives power from the power supply device 43 emits light of a predetermined wavelength. The light emitted from the light emitting element 42a enters the light scattering member 45 through the introducing portion 42b, and is irregularly reflected by the light diffusing material of the light scattering member 45 and the fine uneven shape. Then, the light is emitted as diffused light from the light emitting surface of the light scattering member 45.

As described above, the touch pen 40 is provided with the light emitting unit 42 that emits light, and the light is diffused and emitted from the pen tip. Therefore, when the pen tip of the touch pen 40 contacts the light guide plate 10, part of the infrared light emitted from the pen tip is coupled to the light guide plate 10 and propagates through the light guide plate 10. Since the touch pen 40 diffuses and emits light from the pen tip, the light coupled to the light guide plate 10 is guided and propagated through the light guide plate 10 while diffusing and radiating.

Then, as shown in FIG. 2, light propagating through the light guide plate 10 (hereinafter referred to as “propagating light 10 a, 10 b”) enters the

imaging units

20, 30 through the notches 11. In the

imaging units

20 and 30, an angle formed with the

imaging units

20 and 30 in the two-dimensional plane of the light guide plate 10 at a location where the touch pen 40 contacts is obtained from each image obtained from the imaging element 13. Thereby, based on the calculation principle of the two-dimensional coordinate described below, the position coordinate in the two-dimensional plane can be obtained with high accuracy.

(Calculation of 2D coordinate position)
Using the angle formed with the

imaging units

20 and 30 in the two-dimensional plane of the light guide plate 10 at the location where the touch pen 40 comes into contact, the two-dimensional coordinate position at the location where the touch pen 40 comes into contact is obtained. The calculation method will be described below based on FIGS. 2 and 3 and FIGS. 6 (a) and 6 (b). FIG. 6A is a perspective view illustrating an imaging state of the imaging unit 20 in the pen input device 3 A, and FIG. 6B is a plan view illustrating an image of the imaging unit 23 of the imaging unit 20.

As shown in FIG. 3, first, when the pen tip of the touch pen 40 contacts the surface of the light guide plate 10 in the pen input device 3 A, a part of the infrared light emitted from the touch pen 40 has a refractive index N. Incident in. Of this incident light, the propagation angle θ _P in the light guide plate 10 is
sin (90 ° −θ _P )> 1 / N
The light flux that satisfies the conditions shown in FIG. 5 is confined in the light guide plate 10, and is repeatedly reflected 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. 2, the infrared light emitted from the touch pen 40 is diffused radially with respect to the two-dimensional plane of the light guide plate 10 around the pen tip and propagates in the light guide plate 10. A part of the

propagation light

10a and 10b of the luminous flux is also guided to the end face of the conical cutout 11, and the reflected light of the end face is received by the

imaging units

20 and 30. Specifically, the reflected light of the end face of the notch 11 is collected by the

lenses

21 and 31, subsequently passes through the

filters

22 and 32, and is finally received by the

image sensors

23 and 33. The

filters

22 and 32 transmit light in the wavelength band emitted from the touch pen 40 and play a role of blocking light in other wavelength bands.

Filters

22 and 32 block sunlight, stray light such as liquid crystal display panel backlight light, and increase the SN ratio.

Next, processing of the

imaging units

20 and 30 will be described based on FIGS. 6 (a) and 6 (b). 6A and 6B, only the imaging unit 20 will be described, but the same processing is performed in the imaging unit 30 as well.

As shown in FIGS. 2 and 6A, the light incident on the

imaging units

20 and 30 passes through the

lenses

21 and 31 to form a linear image 25 on the

imaging elements

23 and 33. The position of the linear image 25 changes depending on the position of the touch pen 40, and the angles α and β formed by the

propagation light

10a and 10b and one side of the light guide plate 10 are obtained by analyzing the acquired image of the imaging unit. Then, with the angles α and β, the position coordinates of the point where the pen tip serving as the light emission source is in contact with each other can be obtained using the triangulation method.

Specifically, in FIG. 6 (a), the case where the touch pen 40 is in the position of point P _1, as shown in FIG. 6 (b), the linear image 25 is formed. Also, the touch pen 40 when moved to the position of the point P _2, the image 27 of the line shape is formed.

When the pen tip of the touch pen 40 in the state of irradiating light is not in contact with the light guide plate 10, nothing appears in the acquired image of the image sensor 23. On the other hand, when the pen tip of the touch pen 40 that is in the state of irradiating light from the light emitting unit 42 contacts the light guide plate 10 and infrared light is coupled to the light guide plate 10, the propagation light 10a in a part of the light flux. Is guided to the image sensor 23, a linear image is formed on the imaging surface of the image sensor 23, and a linear image 25 appears on the acquired image.

The position of the linear image 25 shown in FIG. 6B changes depending on the position of the contact point at the pen tip of the touch pen 40, and when the position of the contact point of the pen tip is changed, the linear image 25 becomes It changes like a linear 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 arc as the rotation center) is the above-described certain value of the light guide plate 10 and the line segment connecting the touch pen 40 and the image sensor 23. 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 touch pen 40 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 23, 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 touch pen 40 and the image sensor 23 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) (Formula 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 pen tip contacts are 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 of the pen input position can be obtained.

The interval 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.

In order to obtain the position coordinates of the touch pen 40 by the above method, the coordinate input system 1 is provided with a position coordinate detection unit (not shown). The position coordinate detection unit can be provided in the pen input device 3A.

Further, based on the position coordinates of the touch pen 40 obtained by the above method, the pixel at the position corresponding to the position coordinates of the liquid crystal display panel 2 is driven, and the user visually recognizes the touch position of the touch pen 40. Is possible. For this purpose, a control unit (not shown) that controls driving of the liquid crystal display panel 2 may acquire information on the position coordinates obtained by the position coordinate detection unit and drive the liquid crystal display panel 2 based on the information.

(Coordinate detection with multiple touch pens)
In the pen input device 3A and the coordinate input system 1 according to the present embodiment, even when a plurality of touch pens 40 are used, each touch pen 40 can be easily and reliably identified with a simple configuration. Yes. Below, the structure is demonstrated based on FIG. 1 (a) (b), FIG.7, and FIG.8. 1A is a perspective view showing the configuration of the pen input device 3A, and FIG. 1B is a plan view showing the configuration of the

filters

22A and 32A of the pen input device 3A. FIG. 7 is a chart showing the separation distance between the peak wavelengths of the lights emitted from the two

touch pens

40A and 40B. FIG. 8 is a chart showing the sensitivity wavelength dependency of the

image sensors

23 and 33.

As shown in FIG. 1A, in this embodiment, a case where two

touch pens

40A and 40B are used as a plurality of touch pens 40 will be described. In the present invention, even when three or more touch pens 40 are used, the operation and effect thereof are the same as those when the three

touch pens

40A and 40B are used.

First, the light emitting units 42 of the touch pens 40A and 40B according to the present embodiment emit light having different wavelengths. Specifically, as shown in FIG. 7, the wavelengths of the two lights are separated from the peak half-value width of the light having the larger peak width by the interval between the peak wavelengths of the lights. Are different from each other.

That is, there is a possibility that light having a wide peak half width cannot be completely wavelength-separated even if an optical filter is used. For this reason, in order to perform complete separation detection, it is necessary to select a wavelength in consideration of the half-value width of the light peak. In this regard, in the present embodiment, the wavelength of each light emitted from the

light emitting units

42 and 42 of each

touch pen

40A and 40B is such that the interval between the peak wavelengths of each light is a peak half of the light having the larger peak width. They are different from each other so that they are separated from the price range. As a result, the wavelengths of the light beams emitted from the

light emitting units

42 and 42 of the touch pens 40A and 40B can be sufficiently separated and identified. The wavelength range of light may be visible light such as infrared light, red light or blue light, or ultraviolet light.

In the present embodiment, the

image sensors

23 and 33 as the light receiving units are provided only with the

image sensors

23 and 33 provided at both ends of one side of the light guide plate 10 as in the case of the single touch pen 40. Absent. However, the present invention is not necessarily limited to this, and for example, three or more image sensors can be provided, but two are appropriate in view of member costs. For example, a configuration in which three image sensors are provided and one of them is used as an auxiliary camera may be used.

Here, for example, in the

imaging devices

23 and 33 such as a CMOS (Complementary Metal Oxide Semiconductor) camera or the like, as shown in FIG. Tend to. For this reason, a short wavelength signal may be detected strongly.

Therefore, in the

imaging devices

23 and 33 according to the present embodiment, the intensity of light emitted from the

light emitting units

42 and 42 of the touch pens 40A and 40B depends on the light receiving sensitivity in the wavelength region of the

imaging devices

23 and 33. The detection sensitivity is adjusted to be the same. Specifically, for example, when the wavelengths of light emitted from the

light emitting units

42 and 42 of the touch pens 40A and 40B are 650 nm and 850 nm, the light receiving sensitivity, that is, the quantum efficiency is 50% and 20% according to FIG. Yes, it is 2.5 times. Therefore, in this case, the intensity of the light emitted from the light emitting unit 42 of the touch pen 40A that emits light with a wavelength of 850 nm is relative to the intensity of the light emitted from the light emitting unit 42 of the touch pen 40B that emits light with a wavelength of 650 nm. It is adjusted to 2.5 times.

As a result, it is possible to avoid the strong detection of a signal of a specific wavelength and to align the detection sensitivity.

Next, in the present embodiment, as shown in FIGS. 1A and 1B, the

filters

22A and 32A include the first filter F1 corresponding to the wavelength of the first propagation light L1 from the touch pen 40A and the touch pen 40B. The second filter F2 corresponding to the wavelength of the second propagating light L2 from the first and second propagating lights L1 and L2 emitted in a linear manner and stacked so as to cross the outgoing light of the second propagating light L2 respectively. ing. The first filter F1 and the second filter F2 are continuously and integrally provided. The thicknesses of the first filter F1 and the second filter F2 are each 5 mm, for example.

As a result, in the

image sensors

23 and 33, as shown in FIG. 1B, the light emitted from the touch pen 40A appears as a linear image 25A in the emitted light of the first propagation light L1. Further, the light emitted from the touch pen 40B appears as a linear image 25B in the emitted light of the second propagation light L2. In both cases, an image of two parallel lines appears as parallel lines. The two lines appear in a staggered manner corresponding to the passage of the first filter F1 and the second filter F2.

Therefore, if two

touch pens

40A and 40B are arranged in the line-of-sight direction of one image sensor 23, the image sensor 23 emits light emitted from the touch pen 40A positioned in front of the image sensor 23 and the image pickup As shown in FIG. 1B, the light emitted from the touch pen 40B located behind the element 23 appears as a divided linear image 25A / 25B on the same line at the same time. . The same applies to the other imaging elements 33.

Therefore, it is possible to obtain one side and both angles between the

image pickup devices

23 and 33 in the touch pens 40A and 40B by the respective

image pickup devices

23 and 33, and the pens in the touch pens 40A and 40B are obtained by triangulation. The plane coordinates of the position on the light guide plate 10 in contact can be detected. When there are three touch pens 40, the third filter is disposed on the first filter F1 and the second filter F2, and the light emitted from the third pen crosses the third filter. Similarly, the contact position of the third pen can be easily measured. The same applies even when there are four or more touch pens 40.

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, in the above embodiment, in the

filters

22A and 32A, as shown in FIG. 1B, the boundary between the first filter F1 and the second filter F2 is a straight line. However, the present invention is not particularly limited to this. For example, as shown in FIG. 9, it is possible to use

filters

22B and 32B in which the boundary between the first filter F1 and the second filter F2 is formed in an arc shape. Thereby, since the shape of the notch 11 can be made flat instead of a curved surface, the notch 11 can be easily formed.

As described above, the pen input device 3A according to the present embodiment includes the light guide plate 10 and the touch pens 40A and 40B including the

light emitting units

42 and 42 that make light incident on the light guide plate 10 by contacting the surface of the light guide plate 10. The first propagation light L1 that is incident on the light guide plate 10 from the

light emitting units

42 and 42 of the touch pens 40A and 40B and propagates inside the light guide plate 10 and the light emitted from the light guide plate 10 in the second propagation light L2 are received 2 The

image pickup devices

23 and 33 are provided, and the plane coordinates of the position on the light guide plate 10 where the touch pens 40A and 40B are in contact are detected.

The touch pens 40A and 40B are provided with at least two light emitting

portions

42 and 42, and each

touch pen

40A and 40B is in contact with the surface of the light guide plate 10 so that light of different wavelengths enters the light guide plate 10. Let Further, the first propagating light L1 or the second propagating light L2 incident on the light guide plate 10 from each touch pen 40A or the touch pen 40B and guiding the inside of the light guide plate 10 is linearly supplied to the two

image sensors

23 and 33, respectively. Is provided with a notch 11 that emits light. Further, a first filter F1 corresponding to the wavelength of the first propagation light L1 and a second filter F2 corresponding to the wavelength of the second propagation light L2 are provided between the optical paths of the light guide plate 10 and the

imaging elements

23 and 33. Are arranged side by side so as to cross the emitted light of the first propagation light L1 and the second propagation light L2 emitted linearly.

Therefore, it is possible to obtain one side and both angles between the

image pickup devices

23 and 33 in the touch pens 40A and 40B by the respective

image pickup devices

23 and 33, and the touch pens 40A and 40B in the touch pens 40A and 40B by the triangulation method. The plane coordinates of the position on the light guide plate 10 in contact with can be detected.

Further, in the present embodiment, the light emitted from the

light emitting units

42 and 42 from the touch pens 40A and 40B does not use the air above the light guide plate 10 as an optical path, but uses the inside of the light guide plate 10 as an optical path. Yes. For this reason, the optical path of the touch pens 40A and 40B is shielded by a finger or the like having the touch pens 40A and 40B, and no interpolation processing is performed to obtain the coordinate positions of the touch pens 40A and 40B. Therefore, detection can be performed reliably and accurately. Further, since the

image pickup devices

23 and 33 are not increased, the touch pens 40A and 40B are easily identified, and the cost is not increased.

Therefore, when using a plurality of

touch pens

40A and 40B at the same time, the touch pens 40A and 40B can be easily and reliably identified without being affected by the fingers operating the touch pens 40A and 40B or the touch pens 40A and 40B. Further, it is possible to provide the pen input device 3A that is performed accurately and avoids an increase in cost.

Further, in the pen input device 3A of the present embodiment,

light scattering members

45 and 45 that allow diffused light to enter the light guide plate 10 are provided at the tips of the touch pens 40A and 40B, respectively.

Thereby, when the light emitted from the

light emitting portions

42 and 42 of the touch pens 40A and 40B is incident on the light guide plate 10, diffused light can be incident on the

light scattering members

45 and 45. As a result, inside the light guide plate 10, light is guided radially from the contact positions of the touch pens 40 A and 40 B to the light guide plate 10, and a sufficient amount of received light can be obtained in any of the

image sensors

23 and 33. Become.

Further, in the pen input device 3A of the present embodiment, the intensity of light emitted from the

light emitting units

42 and 42 of the touch pens 40A and 40B depends on the light receiving sensitivity in the wavelength region of the two

image sensors

23 and 33. The detection sensitivities are adjusted to be the same. Thereby, it is possible to avoid the strong detection of a signal of a specific wavelength and to align the detection sensitivity.

Further, in the pen input device 3A of the present embodiment, the wavelength of each light emitted from the

light emitting units

42 and 42 of each

touch pen

40A and 40B is such that the interval between the peak wavelengths of each light is larger in peak width. They are different from each other so that they are separated from the peak half-width in light. This makes it possible to sufficiently separate and identify the wavelengths of the light beams emitted from the

light emitting units

42 and 42 of the touch pens 40A and 40B.

Further, in the pen input device 3A of the present embodiment, the first filter F1 and the second filter F2 are provided continuously and integrally. Thereby, since the image by the image pick-up element 23 * 33 in several touch pen 40A * 40B does not shift | deviate, coordinate position detection accuracy can be improved.

Further, in the pen input device 3A of the present embodiment, the boundary between the first filter F1 and the second filter F2 can be assumed to be an arc shape.

Thereby, the shape of the notch 11 serving as the optical path changing portion provided in the light guide plate 10 can be changed to a shape in which the corner portion of the light guide plate 10 is cut obliquely with a conical surface or a hyperboloid. As a result, the optical path conversion unit can be easily formed.

The coordinate input system 1 according to the present embodiment is a coordinate input system including the pen input device 3A according to the present embodiment, and includes a liquid crystal display panel 2. For this reason, the pen input device 3 A can function as a touch panel that performs pen input while viewing an image on the liquid crystal display panel 2. Therefore, when a plurality of

touch pens

40A and 40B are used, each

touch pen

40A and 40B is easily and reliably identified without being affected by the touch pens 40A and 40B or the fingers operating the touch pens 40A and 40B. The coordinate input system 1 including the pen input device 3A that avoids an increase in cost 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 the first embodiment are given the same reference numerals, and explanation thereof is omitted.

In the pen input device 3A and the coordinate input system 1 in the first embodiment, the detected object uses two

touch pens

40A and 40B. However, the coordinate input device 3B and the coordinate input system 1 according to the present embodiment are different in that a finger and one touch pen 40 can be used simultaneously as a detection target.

First, a configuration for detecting a finger as a detection target will be described.

(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 FIG. FIG. 10 is a perspective view showing the configuration of the coordinate input system.

The coordinate input system 1 according to the present embodiment includes a liquid crystal display panel 2 as an image display panel and a coordinate input device 3B provided on the upper side of the liquid crystal display panel 2 as shown in FIG.

In the coordinate input system 1, a finger 6 as a detection object is placed on a light guide plate 10 (to be described later) of a coordinate input device 3 B provided on the upper side of the liquid crystal display panel 2 while watching the screen displayed on the liquid crystal display panel 2. By making contact, the coordinates of the contact position on the finger 6 are specified, and desired data can be input.

(Configuration of coordinate input device)
Next, the configuration of the coordinate input device 3B provided in the coordinate input system 1 will be described in detail below based on FIG. 10 and FIG. FIG. 11 is a cross-sectional view taken along line BB in FIG.

As shown in FIG. 10, the coordinate input device 3B includes a light guide plate 10 as a rectangular transparent light guide member,

imaging units

20 and 30 respectively disposed at both ends of one side of the light guide plate 10, and a light guide plate. 10 has a light source unit 4 as a light source provided around three sides and a detection unit 5 as detection means.

That is, the coordinate input device 3B of the present embodiment is different from the pen input device 3A described in the first embodiment in that the light source unit 4 is provided around the light guide plate 10.

That is, in the coordinate input device 3B of the present embodiment, a light source as a light source in which a plurality of LEDs (light emitting diodes) 4a that allow light to enter the light guide plate 10 are arranged around the three sides of the light guide plate 10. A unit 4 is provided along the three sides. These three sides are three sides different from one side of the light guide plate 10 provided with the

imaging units

20 and 30 at both ends. As a result, the light source unit 4 on the three sides of the light guide plate 10 faces the

imaging units

20 and 30, and the

imaging units

20 and 30 are provided within the illumination range of the illumination light from the light source unit 4. It will be. In the present invention, it is not necessarily limited to the periphery of the three sides of the light guide plate 10, for example, the periphery of another side different from the one side of the light guide plate 10 provided with the

imaging units

20 and 30 at both ends. Good.

A plurality of LEDs 4a arranged in the light source unit 4 emit light such as infrared light. However, it is not necessarily limited to infrared light, and may be visible light or ultraviolet light. However, the wavelength of the light of the LED 4a is different from the wavelength of the light emitted from the light emitting unit 42 of the touch pen 40 described in the first embodiment. Further, it is not always necessary to use the LED 4a, and an LD (laser diode) or the like can also be used.

Next, as shown in FIG. 10, the coordinate input device 3B is provided with a detection unit 5 as detection means. The detection unit 5 detects a change in output intensity of the

imaging elements

23 and 33 based on light scattering by the finger 6 and obtains coordinates of a contact position of the finger 6 on the surface of the light guide plate 10. Specifically, it consists of a CPU.

Here, in the coordinate input system 1 of the present embodiment, for example, the finger 6 is used as the detected object. However, the detection target is not necessarily limited to the finger 6 and may be a detection target such as a stick-shaped touch pen.

(Coordinate detection principle of coordinate input device)
The coordinate detection principle when the finger 6 is brought into contact with the light guide plate 10 in the coordinate input device 3B having the above configuration will be described below with reference to FIGS. 12A is a plan view showing an output image of the image sensor 23 when the finger 6 is not in contact with the light guide plate 10, and FIG. 12B is a view when the finger 6 is in contact with the light guide plate 10. 3 is a plan view showing an output image of an image sensor 23. FIG.

First, in the coordinate input device 3B, as shown in FIGS. 10 and 11, light is incident on the light guide plate 10 from a plurality of LEDs 4 a provided along the periphery of at least one side of the light guide plate 10.

The light incident on the light guide plate 10 is guided through the inside of the light guide plate 10 as propagating light, and is emitted to the

image pickup devices

23 and 33 provided in at least two locations via the notches 11. Thereby, in the image pick-up element 23, as shown to Fig.12 (a), the output image of the fan-shaped bright part 23a based on the shape of the notch 11 is obtained. In FIG. 12A, only the output image of the image sensor 23 is shown, but the output image of the image sensor 33 is the same.

In this state, when the finger 6 as the detection object is brought into contact with the surface of the light guide plate 10, the propagation light at the contact position is disturbed. As a result, the intensity of light received by the

image sensors

23 and 33 is reduced. Specifically, as shown in FIG. 12B, a linear dark part BL is generated in the bright part 23a. Therefore, by detecting the dark portion BL indicating the intensity reduction of the amount of received light in the

image sensors

23 and 33, the detection unit 5 can obtain the coordinates of the contact position of the finger 6 on the surface of the light guide plate 10.

This detection principle will be described in detail.

As shown in FIG. 11, infrared light enters a light guide plate 10 having a refractive index N from one LED 4 a provided at an end portion of the light guide plate 10 whose surrounding is air. Of this incident light, the propagation angle θ _P in the light guide plate 10 is
sin (90 ° −θ _P )> 1 / N
The light beam satisfying the condition (total reflection condition) is confined in the light guide plate 10, is repeatedly reflected on the front and back surfaces of the light guide plate 10, and travels in the light guide plate 10.

Here, when a substance having a refractive index Nm contacts the surface of the light guide plate, the total reflection condition is:
sin (90 ° −θ _P )> Nm / N
Therefore, a part of the light cannot satisfy the total reflection condition and is not confined in the light guide plate 10, and a part of the light is incident on the material side having the refractive index Nm. For example, since the refractive index of human skin is about 1.37, the amount of light trapped in the light guide plate 10 is reduced when the finger 6 contacts the light guide plate 10.

That is, if the finger 6 does not contact the light guide plate 10, the illumination light in the light guide plate 10 is totally reflected at the contact position of the finger 6 and is incident on the

image pickup elements

23 and 33. Due to the light scattering due to the presence, the amount of propagating light toward the

image sensors

23 and 33 decreases. As a result, as shown in FIG. 12B, a linear dark portion BL appears in the output image that is the fan-shaped bright portion 23a shown in FIG. Therefore, based on the dark part BL, as described later, the detection unit 5 can obtain the coordinates of the contact position of the finger 6 on the surface of the light guide plate 10. In FIG. 12B, only the output image of the image sensor 23 is shown, but the output image of the image sensor 33 is the same.

(Calculation method of 2D coordinate position)
Based on the dark portions BL of the

image sensors

23 and 33 detected as described above, the calculation method of the two-dimensional coordinate position at the location where the finger 6 is in contact with the detection unit 5 will be described with reference to FIGS. A description will be given below based on a) and (b). FIG. 13A is a perspective view showing an imaging state in the imaging unit 20 in the coordinate input device 3B, and FIG. 13B is a plan view showing an image in the imaging element 23 of the imaging unit 20. FIG.

First, in the present embodiment, triangulation is performed using the angle formed by the

imaging units

20 and 30 and the distance between the

imaging elements

23 and 33 in the two-dimensional plane of the light guide plate 10 at the place where the finger 6 is in contact. The two-dimensional coordinate position at the location where the finger 6 is in contact is calculated by the method.

First, detection of an output image on the

image sensors

23 and 33 when the finger 6 is not in contact with the light guide plate 10 will be described.

First, as shown in FIG. 11, infrared light enters the light guide plate 10 having a refractive index N from one LED 4 a provided at the end of the light guide plate 10. Of this incident light, the propagation angle θ _P in the light guide plate 10 is
sin (90 ° −θ _P )> 1 / N
The light flux that satisfies the conditions shown in FIG. 5 is confined in the light guide plate 10, and is repeatedly reflected 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. 10, the propagation lights 10 a and 10 b in a part of the light flux are guided to the end faces of the

conical cutouts

11 and 11, and the reflected light from the end faces is reflected by the imaging unit 20. • Light is received at 30. Specifically, the reflected light of the end faces of the

notches

11 and 11 is collected by the

lenses

21 and 31, subsequently passed through the

filters

22 and 32, and finally received by the

image sensors

23 and 33. The

filters

22 and 32 transmit light in the wavelength band emitted by the LED 4a and play a role of blocking light in other wavelength bands.

Filters

Next, as shown in FIG. 13A, the light incident on the image pickup unit 20 forms a linear image on the image pickup device 23 via the lens 21. Here, a plurality of LEDs 4a... Exist and enter the light guide plate 10 from a wide range of angles. For this reason, as shown by the alternate long and short dash line in FIG. 13B, a plurality of linear images are gathered on the image sensor 23 to form a fan shape, and as shown in FIG. It appears as an output image of the part 23a.

Next, in this state, as shown in FIG. 13 (a), the detection will be described of the output image on the

imaging element

23, 33 when the finger 6 which is in contact with the position of for example the point P ₁ in the light guide plate 10.

In this case, as shown in FIG. 11, by contact with the light guide plate 10 of the finger 6, the light propagation angle theta _P of the light guide plate 10 is disturbed, as a result, amount of light is Genchijimi. The propagating light 10a with the light amount reduced is guided to the end face of the conical cutout 11, and the reflected light of the end face is received by the imaging unit 20. The light incident on the imaging unit 20 via the lens 21, as shown in FIG. 13 (b), to form a linear image of the dark portion BL ₁ in the fan-shaped light portion 23a in the image pickup device 23 .

Further, the finger 6 when moved to the position of the point P _2, the image of the linear dark portion BL ₂ is formed.

The positions of the linear dark portions BL ₁ and BL ₂ shown in FIG. 13B change depending on the position of the contact point on the finger 6. If the position of the contact point of the finger 6 is changed, the linear dark portion BL is changed. ₁ of the image changes as the image of the linear dark portion BL _2. The locus of the images of the linear dark portions BL ₁ and BL ₂ exists inside the fan-shaped bright portion 23a indicated by the alternate long and short dash line. The inclination angle α ₁ ′ of the line segment connecting the fan-shaped center and the image of the linear dark part BL ₁ (with the center of the arc as the center of rotation) is the line segment connecting the finger 6 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 of the

imaging units

20 and 30 side. Therefore, the inclination angle α ₁ ′ is obtained from the acquired image of the image sensor 23, and the angle α ₁ is obtained from the inclination angle α ₁ ′. Similarly, when the finger 6 is moved to the position of the point P _2, the image of the linear dark portion BL ₂ is formed, by obtaining the inclination angle alpha _{2 'in} its linear dark portion BL ₂ of the image, the angle alpha ₂ Is required.

Similarly, for the image sensor 23, the position of the contact point of the finger 6 is specified from the analysis of the acquired image, and a line segment connecting the finger 6 and the image sensor 23 is formed by one side of the light guide plate 10 on the

image pickup unit

20 or 30 side. An angle β is determined.

Then, the interval between the image sensor 23 and the image sensor 33 is L, the angle of the contact point obtained by reading the image from the image sensor 23 is α, and the angle of the contact point obtained by reading the acquired image from the image sensor 23 is obtained. Where β is the coordinate (X, Y) of the contact point, the following relational expression (5) and relational expression (6)
Y = tan α · X (5)
Y = tan β · (L−X) (Formula 6)
Satisfied. Solving this, the coordinates (X, Y) of the contact point are
X = tan β · L / (tan α + tan β) (7)
Y = (tan α · tan β) · L / (tan α + tan β) (8)
The coordinates X · Y of the point where the finger 6 touches are obtained from the angles α · 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. Therefore, by obtaining the angles α and β, the coordinates X and Y of the contact position of the finger 6 can be obtained.

Based on the contact position coordinates of the finger 6 obtained by the above method, the user can visually recognize the touch position of the finger 6 by driving a pixel at a position corresponding to the position coordinate of the liquid crystal display panel 2. It is possible to make it possible. For this purpose, a control unit (not shown) that controls driving of the liquid crystal display panel 2 may acquire information on the position coordinates obtained by the position coordinate detection unit and drive the liquid crystal display panel 2 based on the information.

As described above, the coordinate input device 3B of the present embodiment includes the plate-shaped light guide plate 10, the light source unit 4 that makes the illumination light incident from the end of the light guide plate 10, and the illumination light that propagates in the light guide plate 10. Based on the outputs of the

imaging units

20 and 30 that detect light scattering by the finger 6 when the finger 6 comes into contact with the surface of the light guide plate 10 and at least two

imaging units

20 and 30 that receive light, the light guide plate 10 in the finger 6. And a detection unit 5 for obtaining coordinates of a position of contact with the surface.

Here, in the touch panel of Patent Document 3, in the state where the amount of light received by the light receiving means is maintained at 0, the light reception peak of the scattered light due to the presence of the detection target is detected. As a result, if the light receiving means is not arranged outside the irradiation range of the light source, the amount of light received by the light receiving means cannot be maintained at 0, and the amount of scattered light received by the detected object is very small. The signal quality of the contact detection in the to-be-detected body in the distance from the means is lowered, and there is a problem that it is difficult to apply to a large touch panel.

Therefore, in the present embodiment, the

imaging units

20 and 30 as light receiving means are provided within the illumination light irradiation range, and the detection unit 5 includes the

imaging units

20 and 30 based on light scattering by the finger 6. A change in output intensity is detected, and coordinates of the contact position of the finger 6 on the surface of the light guide plate 10 are obtained.

That is, in the present embodiment, the idea is changed with respect to Patent Document 3, and in Patent Document 3, the received light peak of scattered light due to the presence of the detected object is detected, whereas in the present embodiment, A change in output intensity in the

imaging units

20 and 30 is detected based on light scattering caused by the presence of the finger 6 in a state where a certain amount of received light is given to the

imaging units

20 and 30 from the beginning.

As a result, since the

imaging units

20 and 30 are provided within the illumination light irradiation range, the

imaging units

20 and 30 are constantly given a constant amount of received light, and in that state, far from the

imaging units

20 and 30. Due to the light scattering caused by the contact of the finger 6 at this point, the intensity is reduced in the constant amount of received light. For this reason, by detecting this strength reduction, the coordinates of the contact position of the finger 6 on the surface of the light guide plate 10 can be obtained by the detection unit 5.

Therefore, even when the optical coordinate input device 3B using the light guide plate 10 is applied to a large touch panel, the coordinate input device 3B that can detect the coordinate position of the detection target such as the finger 6 can be provided. .

Further, in the coordinate input device 3B of the present embodiment, the

imaging units

20 and 30 have a two-dimensional image sensor, and the light guide plate 10 receives illumination light propagating through the light guide plate 10 as an imaging unit. Cutouts 11 are respectively provided in a linear shape to 20 and 30.

Thereby, the illumination light propagating in the light guide plate 10 and the attenuated light by the finger 6 are respectively emitted to the outside of the light guide plate 10 through the notches 11, and are respectively supplied to the

image pickup devices

23 and 33 of the

image pickup units

20 and 30. It is emitted linearly.

For this reason, in each

imaging unit

20, 30, since the interval between each

imaging unit

20, 30 in the triangle connecting each

imaging unit

20, 30 and the contact position of the finger 6 to the light guide plate 10 and two angles are known, The detection unit 5 can obtain the coordinates of the contact position of the finger 6 with the light guide plate 10 by triangulation.

Accordingly, the coordinate input device 3B is provided that uses the light guide plate 10 and obtains the coordinates of the contact position of the finger 6 with the light guide plate 10 by triangulation by light scattering due to the contact of the finger 6 with the light guide plate 10. be able to.

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 panel 2.

Thereby, the coordinate input device 3B can be made to function as a touch panel for inputting with a detected body such as the finger 6 while viewing the image of the liquid crystal display panel 2. Therefore, in the optical coordinate input device 3B using the light guide plate 10, even when applied to a large touch panel, the coordinate input system provided with the coordinate input device 3B that can detect the coordinate position of the detected object such as the finger 6 or the like. 1 can be provided.

(Simultaneous use of finger and touch pen)
As described above, the coordinate input device 3B according to the present embodiment can detect the coordinates of the contact position of the finger 6 by bringing the finger 6 into contact with the light guide plate 10, and the pen for the touch pen 40. Only the light source unit 4 is added to the input device 3A. Therefore, the finger 6 and the touch pen 40 can be used simultaneously.

The processing at this time will be described with reference to FIGS. FIG. 14A is a perspective view showing the overall configuration when the finger 6 and each touch pen 40 are used together in the coordinate input device 3B, and FIG. 14B shows the light guide plate with the finger 6 and each touch pen 40. 10 is a plan view showing an output image of the image sensor 23 when being in contact with the image sensor 10.

First, the LED 4a of the light source unit 4 and the light emitting unit 42 of the touch pen 40 of the present embodiment emit light having different wavelengths. Specifically, as shown in FIG. 7 which is an explanatory diagram of the first embodiment, the wavelengths of the two lights are equal to each other in which the interval between the peak wavelengths of each light is larger. They are different from each other so that they are separated from the full width at half maximum of the peak light.

That is, there is a possibility that light having a wide peak half width cannot be completely wavelength-separated even if an optical filter is used. For this reason, in order to perform complete separation detection, it is necessary to select a wavelength in consideration of the half-value width of the light peak. In this regard, in the present embodiment, the wavelength of each light emitted from the LED 4a of the light source unit 4 and the light emitting unit 42 of the touch pen 40 is the peak in the light having the larger peak width in the interval between the peak wavelengths of each light. They are different from each other so that they are separated from the full width at half maximum. As a result, the wavelengths of the light emitted from the LEDs 4a of the light source unit 4 and the light emitting unit 42 of the touch pen 40 can be sufficiently separated and identified. The wavelength range of light may be visible light such as infrared light, red light or blue light, or ultraviolet light.

Further, in the present embodiment, the

image sensors

23 and 33 as the light receiving units are the

image sensors

23 and 33 provided at both ends of one side of the light guide plate 10 as in the case of one touch pen 40 and one finger 6. Only 33 are provided. However, the present invention is not necessarily limited to this, and for example, three or more image sensors can be provided, but two are appropriate in view of member costs. For example, a configuration in which three image sensors are provided and one of them is used as an auxiliary camera may be used.

Here, for example, in the

imaging devices

23 and 33 such as a CMOS (Complementary Metal Oxide Semiconductor) camera or the like, as shown in FIG. Accordingly, the light receiving sensitivity, that is, the quantum efficiency tends to decrease. For this reason, a short wavelength signal may be detected strongly.

Therefore, in the

imaging devices

23 and 33 of the present embodiment, the intensity of light emitted from the LED 4a of the light source unit 4 and the light emitting unit 42 of the touch pen 40 depends on the light receiving sensitivity in the wavelength region of the

imaging devices

23 and 33. The detection sensitivity is adjusted to be the same. Specifically, for example, when the wavelengths of light emitted from the LED 4a of the light source unit 4 and the light emitting unit 42 of the touch pen 40 are 650 nm and 850 nm, the light receiving sensitivity, that is, the quantum efficiency is 50% and 20% according to FIG. It is 2.5 times. Therefore, in this case, the intensity of light emitted from the LED 4a of the light source unit 4 that emits light with a wavelength of 850 nm is 2 with respect to the intensity of light emitted from the light emitting unit 42 of the touch pen 40 that emits light with a wavelength of 650 nm. It is adjusted to 5 times.

Next, also in the present embodiment, as shown in FIG. 1B, which is an explanatory diagram of the first embodiment, the

filters

22A and 32A have a first wavelength corresponding to the wavelength of the first propagation light L1 from the finger 6. The first filter F1 and the second filter F2 corresponding to the wavelength of the second propagation light L2 from the touch pen 40 are linearly emitted so as to cross the emitted light of the first propagation light L1 and the second propagation light L2, respectively. Are arranged in layers. The first filter F1 and the second filter F2 are continuously and integrally provided. The thicknesses of the first filter F1 and the second filter F2 are each 5 mm, for example.

Here, also in the present embodiment, the boundary between the first filter F1 and the second filter F2 can be arcuate.

As a result, in the

image sensors

23 and 33, as shown in FIG. 14B, the image when the finger 6 is in contact with the light guide plate 10 is the linear dark portion BL in the emitted light of the first propagation light L1. It appears. Moreover, the light emitted from the touch pen 40 appears as a linear bright portion 23b in the emitted light of the second propagation light L2. Both appear as an image of a line extending radially in the radial direction around the center of the fan shape. The two lines appear in a staggered manner corresponding to the passage of the first filter F1 and the second filter F2.

Therefore, if the finger 6 and the touch pen 40 are arranged in the line-of-sight direction of one image sensor 23, the image sensor 23 has an image from the finger 6 positioned in front of the image sensor 23 and the image sensor 23. Images of light emitted from the touch pen 40 located at the back of the screen appear as divided linear dark portions BL and bright portions 23b on the same radial line, respectively. Note that when the finger 6 and the touch pen 40 overlap in the direction of the line of sight from the image sensor 33, the same phenomenon appears in the image sensor 33.

Therefore, it is possible to obtain one side and both corners of the finger 6 and the touch pen 40 between the

image pickup devices

23 and 33 by the respective

image pickup devices

23 and 33, and the finger 6 and the touch pen 40 are contacted by the triangulation method. The plane coordinates of the position on the light guide plate 10 can be detected. When there are a total of three fingers 6 and touch pens 40, the third filter is disposed so as to be stacked on the first filter F1 and the second filter F2, and the emitted light of the third detected object is also the first. Since the three filters are crossed, similarly, the contact position of the third object to be detected can be easily measured. The same applies even when there are four or more detected objects.

As described above, in the coordinate input device 3B of the present embodiment, the light source unit 4 is provided as a light source that makes the illumination light incident from the end of the light guide plate 10, and the finger 6 as the first detected body is the light guide plate. The illumination light propagating through the light guide plate 10 is scattered by contacting the surface of the light guide 10. On the other hand, the touch pen 40 as the second object to be detected is composed of a light emitting pen having a light emitting unit 42 that makes light having a wavelength different from that of illumination light incident upon contact with the surface of the light guide plate 10. The

imaging elements

23 and 33 as light receiving parts are illumination light propagating through the light guide plate 10 and first propagation light L3 that is scattered light by the finger 6, and light from the light emitting part 42 by the touch pen 40. 2 propagation light L4 is received. The detection unit 5 as detection means detects a change in the output intensity of the

imaging elements

23 and 33 based on scattering of illumination light due to contact of the finger 6 with the light guide plate 10 to detect the surface of the light guide plate 10 on the finger 6. The position of the touch position on the surface of the light guide plate 10 in the touch pen 40 based on the output of the

image sensors

23 and 33 that receive the second propagation light L4 due to the touch pen 40 contacting the light guide plate 10. Find the coordinates of.

According to the above configuration, the finger 6 scatters illumination light propagating through the light guide plate 10 by contacting the surface of the light guide plate 10, while the touch pen 40 illuminates by contacting the surface of the light guide plate 10. The light-emitting pen includes a light-emitting unit 42 that allows light having a wavelength different from that of light to enter.

That is, in the present embodiment, the touch pen 40 is a light-emitting pen having a light-emitting portion 42 that makes light incident upon contact with the surface of the light guide plate 10. For this reason, the coordinates of the contact position of the touch pen 40 can be obtained based on the detection principle of the touch pen 40 which is the light-emitting pen described in the first embodiment. Specifically, the

image sensors

23 and 33 receive the second propagation light L4 that is light from the light emitting unit 42 by the touch pen 40. Then, the detection unit 5 determines the coordinates of the contact position of the touch pen 40 on the surface of the light guide plate 10 based on the outputs of the

imaging elements

23 and 33 that receive the second propagation light L4 due to the touch pen 40 contacting the light guide plate 10. Ask.

On the other hand, the finger 6 scatters the illumination light propagating through the light guide plate 10 by contacting the surface of the light guide plate 10.

In order to detect the detection target such as the finger 6 that does not emit such light by the

imaging elements

23 and 33, it is necessary to make the illumination light incident from the end of the light guide plate 10 in advance. Therefore, in the present embodiment, the light source unit 4 that allows illumination light to enter from the end of the light guide plate 10 is provided.

In such a coordinate input device 3B, the

imaging elements

23 and 33 receive the illumination light propagating in the light guide plate 10 and the first propagation light L3 that is the scattered light from the finger 6. And the detection part 5 detects the change of the output intensity of the image pick-up element 23 * 33 based on the scattering of the illumination light by the contact to the light guide plate 10 of the finger | toe 6, and the contact position to the surface of the light guide plate 10 in the finger | toe 6 Find the coordinates of.

Thereby, the contact position of the first object to be detected consisting of the finger 6 and the like to the light guide plate 10 can be obtained.

By the way, in such a coordinate input device 3B, the first detected body made of the finger 6 and the like and the second detected body such as the touch pen 40 made of the light emitting pen are used simultaneously, and the finger 6 and the touch pen 40 are detected. When light in the same wavelength region is used, when the finger 6 and the touch pen 40 are arranged in the line-of-sight direction of the

image pickup devices

23 and 33, the image of the detection object positioned in the back as viewed from the

image pickup devices

23 and 33. And the image of the object to be detected in front of each other overlap, so that there is a problem that the position cannot be detected by the triangulation method.

In order to solve this problem, for example, light of a different wavelength is used for the finger 6 and the touch pen 40, and the imaging element 23 as a pair of first light receiving units essential for the finger 6 and the touch pen 40. And two sets of the image sensor 33 as the second light receiving unit are prepared, the number of parts of the apparatus increases and the cost increases.

Therefore, in the present embodiment, even when the finger 6 and the touch pen 40 are used at the same time, first, the

image sensors

23 and 33 are at least one pair of the first light receiving unit and the second light receiving unit that are essential in the triangulation method. Only the

image pickup devices

23 and 33 are provided. And in order to identify the finger | toe 6 and the touch pen 40 with the image pick-up elements 23 * 33, it has the following structures.

First, the touch pen 40 is a light-emitting pen having a light-emitting portion 42 that makes light having a wavelength different from the illumination light from the LED 4a of the light source unit 4 come into contact with the surface of the light guide plate 10. Next, between the optical path between the light guide plate 10 and each of the

image sensors

23 and 33, a first filter F1 corresponding to the wavelength of the first propagation light L3 and a second filter F2 corresponding to the wavelength of the second propagation light L4, Are arranged side by side so as to cross the emitted light of the first propagation light L3 and the second propagation light L4 emitted linearly.

Thereby, for example, the emitted light of the first propagation light L3 based on the contact of the finger 6 is emitted linearly to the two

image pickup devices

23 and 33 via the notch 11 and the first filter F1 as the optical path changing unit. Is done. Similarly, the emitted light of the second propagation light L4 based on the touch of the touch pen 40 is similarly emitted linearly to the two

image pickup devices

23 and 33 through the notch 11 and the second filter F2.

Here, the first filter F1 and the second filter F2 are arranged side by side so as to cross the emitted light of the first propagation light L3 and the second propagation light L4 emitted linearly. For this reason, for example, when the boundary between the first filter F1 and the second filter F2 has an arc shape, the

imaging elements

23 and 33 have dark portions that are linear images of the emitted light of the first propagation light L3. Two images of BL and the bright portion 23b, which is a linear image of the emitted light of the second propagation light L4, appear as images of lines extending radially in the radial direction around the center of the fan shape. The two lines appear in a staggered manner corresponding to the passage of the first filter F1 and the second filter F2. Note that when the boundary between the first filter F1 and the second filter F2 is not a circular arc but a straight line, the images appear in parallel.

As a result, if the finger 6 and the touch pen 40 are lined up in the line-of-sight direction of one image sensor 23, the image sensor 23 causes the first propagating light based on the contact of the finger 6 located in front of the image sensor 23. The second propagating light L4 based on the contact of the touch pen 40 positioned at the back as viewed from L3 and the image sensor 23 appears as a divided line on the same line at the same time.

image pickup devices

23 and 33 by the respective

image pickup devices

23 and 33, and the finger 6 and the touch pen 40 are contacted by triangulation. The plane coordinates of the position on the light guide plate 10 can be detected. When there are three detected bodies, the third filter is disposed on the first filter and the second filter, and the third propagation light based on the contact of the third detected body is further emitted. Since the incident light also crosses the third filter, similarly, the contact position of the third detected object can be easily measured. The same applies even when there are four or more detected objects.

Further, in the present embodiment, the first propagation light L3 based on the contact of the finger 6 and the second propagation light L4 based on the contact of the touch pen 40 do not use the air above the light guide plate 10 as an optical path. The inside of the optical plate 10 is an optical path. For this reason, since the optical path of the touch pen 40 is shielded by a finger or the like having the touch pen 40 and no interpolation processing is performed to obtain the coordinate position of the touch pen 40, detection can be performed reliably and accurately. Further, since the

image pickup devices

23 and 33 are not increased, the finger 6 and the touch pen 40 are easily identified, and the cost is not increased.

Therefore, when a plurality of fingers 6 and the touch pen 40 are used at the same time, each finger 6 and the touch pen 40 are easily and reliably identified without being affected by each other's finger 6 or the touch pen 40, thereby avoiding an increase in cost. A coordinate input device can be provided.

Further, in the coordinate input device 3B of the present embodiment, the intensity of each light emitted from the LED 4a of the light source unit 4 and the light emitting unit 42 of the touch pen 40 depends on the light receiving sensitivity in the wavelength region of the

image sensors

23 and 33. The detection sensitivities are adjusted to be the same.

That is, for example, in a light receiving part of a CMOS (Complementary Metal Oxide Semiconductor) camera or the like, the light receiving sensitivity tends to decrease as it goes to the long wavelength side. For this reason, a short wavelength signal may be detected strongly. In this regard, in the present embodiment, the intensity of each light emitted from the LED 4a of the light source unit 4 and the light emitting unit 42 of the touch pen 40 depends on the light receiving sensitivity in the wavelength region of the

image sensors

23 and 33. Are adjusted to be the same. As a result, it is possible to avoid the strong detection of a signal having a specific wavelength and to make the detection sensitivity uniform.

In the coordinate input device 3B of the present embodiment, the wavelength of each light emitted from the LED 4a of the light source unit 4 and the light emitting unit 42 of the touch pen 40 is such that the interval between the peak wavelengths of each light is larger in peak width. They are different from each other so that they are separated from the full width at half maximum of the peak light.

That is, there is a possibility that light having a wide peak half width cannot be completely wavelength-separated even if an optical filter is used. For this reason, in order to perform complete separation detection, it is necessary to select a wavelength in consideration of the half-value width of the light peak. In this regard, in the present embodiment, the wavelength of each light emitted from the LED 4a of the light source unit 4 and the light emitting unit 42 of the touch pen 40 is the peak in the light having the larger peak width in the interval between the peak wavelengths of each light. They are different from each other so that they are separated from the full width at half maximum. As a result, the wavelengths of the light emitted from the LEDs 4a of the light source unit 4 and the light emitting unit 42 of the touch pen 40 can be sufficiently separated and identified.

Further, in the coordinate input device 3B of the present embodiment, the first filter F1 and the second filter F2 are provided continuously and integrally. Thereby, since the image by the image pick-up element 23 * 33 in the finger | toe 6 and the touch pen 40 does not shift | deviate, coordinate position detection accuracy can be improved.

Further, in the coordinate input device 3B of the present embodiment, the boundary between the first filter F1 and the second filter F2 has an arc shape. Thereby, since the shape of the notch 11 provided in the light guide plate 10 can be made into a shape in which the corner portion of the light guide plate 10 is cut obliquely with a conical surface or a hyperboloid, the notch 11 can be easily formed. Can be formed.

Further, the coordinate input system 1 of the present embodiment is a coordinate input system 1 including the coordinate input device 3B of the present embodiment, and includes a liquid crystal display panel 2 as an image display panel.

For this reason, the coordinate input device 3B can function as a touch panel for pen input and finger input while viewing the image on the liquid crystal display panel 2. Therefore, when the finger 6 and the touch pen 40 are used at the same time, the coordinates for easily and surely identifying each finger 6 and the touch pen 40 without being influenced by the mutual finger 6 and the touch pen 40 and avoiding an increase in cost. A coordinate input system 1 including the input device 3B can be provided.

[Embodiment 3]
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 and the second embodiment. For convenience of explanation, members having the same functions as those shown in the drawings of Embodiment 1 and Embodiment 2 are given the same reference numerals, and explanation thereof is omitted.

In the coordinate input device 3B of the second embodiment, two

image pickup units

20 and 30 are provided.

However, the coordinate input device 3C of the present embodiment is different in that three or

more imaging units

20, 30, 50 are provided as shown in FIG. As a result, it is possible to detect the

fingers

6A and 6B as the two detection objects.

That is, for example, as shown in FIG. 15, when there are two

fingers

6A and 6B as detection objects, and there are only two

imaging units

20 and 30, the optical paths of the two

fingers

6A and 6B overlap. Since the linear dark part BL also overlaps, it cannot be specified which of the two

fingers

6A and 6B is present in front.

However, as shown in FIG. 15, if there are three imaging

units

20, 30, and 50, each finger 6 A, 6 B uses each

imaging unit

20, 30, 50 with two optical paths that do not overlap each other. 6 contact positions can be obtained. The imaging unit 50 includes a lens 51, a filter 52A, and an imaging element 53.

Specifically, for example, in FIG. 15, when the finger 6B is present at point P _3, it overlaps the optical path of the finger 6B finger 6A to the imaging unit 20. In this case, two

imaging units

30 and 50 are used to detect the finger 6A, while the

imaging units

20 and 50 are used to detect the finger 6B. As a result, the optical paths do not overlap.

Therefore, the position coordinates of the contact points of the

fingers

6A and 6B can be reliably specified regardless of where the two

fingers

6A and 6B are in contact with the light guide plate 10.

In general, when there are M fingers 6 as detection objects, the required number N of light receiving means is:
N = M + 1
It becomes.

On the other hand, when at least three

imaging units

20, 30, 50 are provided, there are the following merits.

That is, in the case of two

imaging units

20 and 30, when the finger 6A comes in contact with the vicinity of the side of the light guide plate 10 provided with the two

imaging units

20 and 30, a blind spot is formed, and the two imaging units 20・ There is a possibility that it will not be detected at 30. In this case, if there are three light receiving portions, for example, if they are arranged at the vertices of a triangle, the finger 6A can be brought into contact with any location of the light guide plate 10 without generating a blind spot. The position coordinates of the contact point of the finger 6A can be reliably specified.

In this case, for example, as shown in FIG. 16, the

imaging units

20, 30, 50, and 60 having the light receiving portions can be disposed at the four corners of the rectangular light guide plate 10.

Here, when the four

image pickup units

20, 30, 50, 60 having the light receiving portions are arranged at the respective corner portions of the rectangular light guide plate 10, a light source as a light source as shown in FIG. It is preferable that the units 4... Be arranged at the end of the entire periphery of the light guide plate 10 and the light source units 4... Be a coordinate input device 3D that allows illumination light to enter from the end of the entire periphery of the light guide plate 10. . As a necessary condition, when the number of

imaging units

50 and 60 as light receiving means is increased around the light guide plate 10, it is preferable that a light source exists at a position opposite to the

imaging units

50 and 60.

Thus, the four

imaging units

20, 30, 50, and 60 having the light receiving units are provided with the entire range in the light guide plate 10 within the illumination light irradiation range. Therefore, it is possible to reliably specify the position coordinates of the contact point of the finger 6A, regardless of where the finger 6A is in contact with the light guide plate 10.

Also, since the light source units 4 and the

imaging units

20, 30, 50, 60 are arranged to face each other, the degree of freedom of arrangement of the

imaging units

20, 30, 50, 60 is increased. In addition, the number of

image pickup units

20, 30, 50, 60 can be easily increased, and simultaneous detection of the contact of a large number of

fingers

6A, 6B... Is possible, resulting in a decrease in signal quality when applied to a large touch panel. hard.

Here, when four

image pickup units

20, 30, 50, 60 are provided, any two of the four

image pickup units

20, 30, 50, 60 are used for detecting the finger 6A. can do.

However, for example, when the

imaging units

20 and 30 are arranged along one side of the light guide plate 10, the signal quality is deteriorated when the contact point of the finger 6A is far from the

imaging units

20 and 30. Therefore, when the contact point of the finger 6A is far from the

imaging units

20 and 30, by increasing the number of

imaging units

50 and 60 as light receiving means around the light guide plate 10, the

imaging units

50 and 60 adjacent to the finger 6A can be increased. By detecting this, it is possible to detect without degrading the signal quality.

Note that it is possible to determine whether they are close to each other based on whether the signal attenuation is large or small. In other words, it can be said that the closer the signal attenuation, the closer.

As described above, in the coordinate input device 3C of the present embodiment, at least three light receiving units are provided as the

imaging elements

23, 33, and 53 of the

imaging units

20, 30, and 50.

Thereby, for each

finger

6A, 6B, it is possible to obtain the contact position of each

finger

6A, 6B by using the

imaging units

30, 50 and the

imaging units

20, 50 with two optical paths that do not overlap.

Further, by arranging the three

imaging units

20, 30 and 50 at the apexes of the triangle, the finger 6A can be brought into contact with any position of the light guide plate 10 without causing a blind spot. It is possible to reliably specify the position coordinates of the point.

Furthermore, in the coordinate input device 3D of the present embodiment, the light source unit 4 is configured to allow illumination light to enter from the entire peripheral edge of the light guide plate 10. As a result, the

imaging units

20, 30, 50, and 60 have the entire range of the light guide plate 10 within the illumination light irradiation range.

Therefore, it is possible to reliably specify the position coordinates of the contact point of the finger 6A regardless of where the finger 6A is brought into contact with the light guide plate 10.

In such a configuration, the

imaging units

20, 30 and 50 have the

filters

22A, 32A and 52A.

Therefore, when the two

fingers

6A and 6B as the detection target and the touch pen 40 are used at the same time, the respective contact positions can be specified.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and the technical means disclosed in the other embodiments are appropriately combined. The obtained embodiment is also included in the technical scope of the present invention.

The present invention can be used for an optical coordinate input device and a coordinate input system that simultaneously use a plurality of detection objects such as fingers or a bar-shaped operation member pen such as a touch pen or a stylus pen.

1 Coordinate input system 2 Liquid crystal display panel (image display panel)
3A Pen input device (coordinate input device)
3B Coordinate input device 4 Light source unit (light source)
4a LED
5 Detection part (detection means)
6 fingers (detected body)
6A finger (object to be detected)
6B Finger (Detected object)
10 Light guide plate (light guide member)
10a Propagating light 10b Propagating light 11 Notch (optical path changing unit)
20 Imaging unit 21 Lens 22 Filter 22A Filter 23 Imaging device (light receiving unit)
23a Bright part 23b Bright part 25 Image 25A Image 27 Image 30 Imaging unit 31 Lens 32 Filter 32A Filter 33 Imaging element (light receiving part)
40 Touch pen (light emitting pen, object to be detected)
40A touch pen (light emitting pen, object to be detected)
40B Touch pen (light emitting pen, object to be detected)
42 Light-Emitting Unit 45 Light Scattering Member 50 Imaging Unit 60 Imaging Unit BL Dark Part BL ₁ Dark Part BL ₂ Dark Part F1 First Filter F2 Second Filter L Interval L1 First Propagation Light (Propagation Light)
L2 Second propagation light (propagation light)

Claims

A plate-shaped light guide member, at least two light receiving portions for receiving propagation light propagating in the light guide member, and propagation light based on the contact when the detected object comes into contact with the surface of the light guide member A coordinate input device comprising detection means for obtaining coordinates of a position of contact with the surface of the light guide member in the detected body based on the detected output of the light receiving unit;
The detected object comprises at least two first detected objects and a second detected object,
The first propagating light based on the contact of the first detected object and the second propagating light based on the contact of the second detected object have different wavelengths, and
The light guide member is provided with an optical path conversion unit that linearly emits the first propagation light or the second propagation light to the two light receiving units,
A first filter corresponding to the wavelength of the first propagation light and a second filter corresponding to the wavelength of the second propagation light are linearly provided between the optical paths of the light guide member and the light receiving portions. A coordinate input device, wherein the emitted light of the first propagation light and the second propagation light emitted is arranged side by side so as to cross each other.
The first detected body and the second detected body are each composed of a light emitting pen having a light emitting portion that makes light of different wavelengths incident on the light guide member by contacting the surface of the light guide member. ,
The light receiving unit is configured to transmit the first propagation light and the second propagation light that are incident on the light guide member from the light emitting units of the first detection body and the second detection body, respectively, and propagate through the light guide member. The coordinate input device according to claim 1, wherein light emitted from the light guide member is received.
3. A coordinate input device according to claim 2, wherein a light scattering member for allowing diffused light to enter the light guide member is provided at the tip of each light emitting pen.
The intensity of light emitted from the light emitting unit of each light emitting pen is adjusted so that each detection sensitivity is the same according to the light receiving sensitivity in the wavelength region of the light receiving unit. The coordinate input device according to 2 or 3.
The wavelengths of the light emitted from the light emitting portions of the light emitting pens are different from each other such that the interval between the peak wavelengths of the light is separated from the peak half width of the light having the larger peak width. The coordinate input device according to claim 2, 3 or 4.
A light source for allowing illumination light to enter from an end of the light guide member;
The first detected body scatters the illumination light propagating through the light guide member by contacting the surface of the light guide member,
The second object to be detected is composed of a light emitting pen having a light emitting unit that makes light having a wavelength different from the illumination light incident by contacting the surface of the light guide member,
The light receiving unit is illumination light propagating in the light guide member, the first propagation light that is the scattered light by the first detected body, and the second light that is the light from the light emitting unit by the second detected body. While receiving the propagating light,
The detection means detects a change in the output intensity of the light receiving unit based on the scattering of the illumination light due to the contact of the first detected body with the light guiding member, and moves to the surface of the light guiding member in the first detected body. And determining the coordinates of the contact position of the second detected object to the surface of the light guide member on the second detected object based on the output of the light receiving unit that receives the second propagation light due to the contact of the second detected object with the light guide member The coordinate input device according to claim 1, wherein coordinates of the contact position are obtained.
The intensity of each light emitted from the light source and the light emitting part of the second object to be detected is adjusted so that the respective detection sensitivities are the same according to the light receiving sensitivity in the wavelength region of the light receiving part. The coordinate input device according to claim 6.
The wavelength of each light emitted from the light source and the light emitting part of the second object to be detected is such that the interval between the peak wavelengths of each light is separated from the peak half-value width in the light having the larger peak width, The coordinate input device according to claim 6 or 7, wherein the coordinate input devices are different from each other.
The coordinate input device according to any one of claims 1 to 8, wherein the first filter and the second filter are continuously provided integrally.
The coordinate input device according to any one of claims 1 to 9, wherein a boundary between the first filter and the second filter has an arc shape.
A coordinate input system comprising the coordinate input device according to any one of claims 1 to 10,
A coordinate input system comprising an image display panel.