WO2013094376A1 - Input system - Google Patents

Abstract

Provided is an input system that is equipped with a completely flat coordinates input apparatus and a light-emitting pen, and wherein no mis-recognition will happen even if a hand or the like comes in proximity or in contact with the surface of the apparatus. An input system (50) of an embodiment of the present invention is provided with a pen input apparatus (40) and a pen (3) that emits light, and the pen input apparatus (40) comprises: a transparent light-guiding plate (1) onto the surface of which the pen (3) can come in contact, and that can couple the light of the pen (3) so as to be propagated therewithin; and image pickup units (10, 20) that pick up portions of luminous flux propagating within the transparent light-guiding plate (1), at mutually different locations. The contact coordinate-position of the pen (3) is obtained on the basis of the images captured by each of the image pickup units.

Description

Input system

The present invention relates to an input system using a pen having a light emitting unit.

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

As shown in FIG. 13, the position detection device disclosed in Patent Document 1 has a plurality of plate-like optical absorbers that absorb light inside or an optical shield 102 that shields light at a distance from each other. A plurality of plate-like light guides 101 arranged in parallel, and light detection means 103 for sensing light on the end face of the light guide perpendicular to the plate-like optical absorber or optical shield. When a measurement object 104 (for example, a pen) that emits light is brought into contact with the body surface, the light that has been totally reflected and propagated in a direction parallel to the plate-shaped optical absorber or optical shield in the light guide is reflected by the light. Light is received by the detecting means and the position of the detected object is detected.

In the optical touch screen described in Patent Document 2, as shown in FIG. 14, the display 130 includes PSDs 1000-1 and 1000-2, light sources 1010 and 1020, and light guide units 1030 and 1040. As shown by the line from the light guide unit 1030 in FIG. 14, the light guide unit 1030 uniformly distributes the light from the light source 1010 and guides it to the PSD 1000-1 across the display 130. Similarly, the light guide 1040 can uniformly distribute light and guide it across the display 130 to the PSD 1000-2, as shown by the lines from the light guide 1040 in FIG. Then, when the user brings the stylus 720 into contact with the upper surface of the display 130 at the point 1050 in FIG. 14, a part of the light guided from the light guide unit 1030 hinders reaching the PSD 1000-1 as shown in FIG. It has been. Similarly, part of the light from the light guide unit 1040 is prevented from reaching the PSD 1000-2. Then, PSDs 1000-1 and 1000-2 generate values x1 and y1 corresponding to the X and Y coordinates of contact point 1050 on display 130, respectively. A side view of the display 130 of FIG. 14 is shown in FIG. The display 130 includes a backlight 1110, mirrors 1120 and 1130, PSD 1140, a light guide unit 1150, an active matrix plate 1160, a liquid crystal 1170, and a filter 1180. As shown in FIG. 15, light from the light source 1110 is transmitted through a light guide including a series of external coupling structures similar to the external coupling structure 1155 in the light guide 1150, similar to the light guide 1150. The external coupling structure 1155 prevents total internal reflection of light, guides or couples light from the light guide 1150 to the liquid crystal 1170, and transmits light toward one or more mirrors for reflection to one or more PSDs. In order to guide a part, the light guide 1150 is distributed in the length direction.

In the coordinate input device described in Patent Document 3, as shown in FIG. 16, the light receivers 203a to 203d are arranged on the concave surfaces 200a to 200d around the flat plate member 202 containing the fluorescent dye, and the light source unit 205 is arranged. Fluorescence generated when the flat plate member is irradiated with light from the light is received by each light receiver, and the coordinates of the light irradiation point are obtained from the fluorescence intensity measured by each light receiver. Light absorbing members 204a to 204d for preventing stray light are disposed on the sides of the flat plate member 202 other than the concave surfaces 200a to 200d.

JP 2004-338168 A (released on December 2, 2004) Special table 2011-522303 gazette (announced July 26, 2011) Japanese Patent Laid-Open No. 11-327769 (published on November 30, 1999)

However, the above-described position detection device of Patent Document 1 includes a light guide body 101 having a complicated structure in which a plurality of optical absorbers or optical shields 102 are arranged in parallel at a distance from each other. The light detection means 103 is provided for the light guide region. This complicates the apparatus and increases costs. In FIG. 13, only one of the two-dimensional coordinates (x coordinate, y coordinate) can be specified. If two-dimensional coordinates are to be obtained, in addition to the structure shown in FIG. 13, the same structure as that shown in FIG. 13 must be arranged so that the light guide directions are orthogonal to each other. This increases the size of the apparatus and further increases costs.

Also, the optical touch screen of Patent Document 2 described above performs position detection by blocking light spreading on the upper surface of the display 130. For this reason, if an object other than a pen is touched in the detection area, infrared light in the vicinity of the object is blocked, so that it is erroneously recognized as a pen input. In particular, if the palm touches the detection area by mistake, the pen touch on the optical path shielded by the palm cannot be recognized. In addition, when the optical touch screen of Patent Document 2 is applied to a table-type terminal, it is assumed that books, paper materials, dishes, cups, and the like are placed on the table surface. Have difficulty. That is, the light shielding method has a problem that erroneous recognition is likely to occur when a detection object other than one pen touches the detection area. Further, in the optical touch screen of Patent Document 2, in order to propagate light along the upper surface of the display 130, mirrors 1120 and 1130 are arranged so as to protrude from the upper surface to the upper portion as shown in FIG. For this reason, when applied to a table type terminal, the surroundings rise like a bank, and the table surface cannot be made completely flat. In the light shielding method, when stray light including sunlight enters the photodetector, there is a problem that the contact of the pen cannot be detected due to the influence of the stray light, and it is difficult to place the device outdoors or near a window.

Moreover, although the coordinate input apparatus of the above-mentioned patent document 3 calculates | requires the coordinate of the generation | occurrence | production point of fluorescent light from the difference of the fluorescence intensity of four measurement points, it is easy to be influenced by external light and the accuracy of position coordinate detection is enough. Not. Therefore, when it applies to a pen input device, for example, the subject that a thin line cannot be drawn arises.

The present invention has been made in view of the above problems, and an object of the present invention is an input system including a full flat coordinate input device and a light-emitting pen, which has a simple structure and the device. It is an object of the present invention to provide an input system that is not erroneously recognized even if a hand or the like comes close to or touches a surface.

In order to solve the above problems, an input system according to the present invention is:
A light guide member;
An operation member having a light emitting portion for making light incident on the light guide member by contacting the light guide member;
At least two detection means that are located at positions that do not protrude above the upper surface of the light guide member and that are separated from each other. The at least two detecting means for detecting propagating light propagating through the inside of the optical member,
The detecting means detects a position coordinate of a point where the light emitting unit contacts the light guide member by detecting a traveling direction of the propagated light from the detected propagated light. Yes.

According to the above configuration, the position coordinates are obtained by capturing the light that has propagated to at least two locations apart from each other in the light guide member. That is, even if the detection means is placed at each location, the total number of detection devices may be two. In some cases, the detection devices can be collected from each location by a mirror or the like. There is no need to arrange a light receiving element (imaging element) in each light guide region. For this reason, the apparatus is not complicated or enlarged, and costs are not increased.

Further, according to the above configuration, the light guide member does not require a complicated structure and does not cost.

Further, according to the above configuration, the detection unit is provided at a position that does not protrude upward from the upper surface of the light guide member. Since it is the structure which each captures the light which propagates inside, the upper surface of a light guide member can be made into the uppermost surface of a coordinate input device, and there is nothing which protrudes upwards from a light guide member. Therefore, even when this input device is applied to a table type terminal, the table surface can be made completely flat without the surroundings being raised like a bank.

Further, according to the above configuration, there is no need to prepare a plurality of light guide members in order to obtain a two-dimensional position coordinate as in Patent Document 1, which can contribute to downsizing of the apparatus.

Moreover, according to said structure, since the light which propagated the inside of the light guide member is used instead of the above light-shielding system, there exists no possibility that misrecognition will be caused by the stray light containing sunlight, and an exact position detection is implement | achieved. It is therefore possible to place the device outdoors or near the window.

Further, according to the above configuration, the coordinate input device as in Patent Document 3 performs position coordinate detection using a change in light intensity, so that the detection accuracy is insufficient due to the influence of external light, but two or more locations. Since the traveling direction of the propagation light can be obtained from the observation point with high accuracy, the point where the propagation light is generated, that is, the point where the light emitting unit contacts the light guide member can be accurately obtained.

Therefore, the present invention having the above-described configuration can provide a highly versatile input device that is fully flat and that is not erroneously recognized even if a hand touches the surface of the device.

Moreover, in addition to said structure, one form of the input system which concerns on this invention is
It is preferable that the light is diffused and radiated to the light guide member when the light emitting unit contacts the light guide member.

According to the above configuration, the position coordinates of the point where the propagation light is generated can be accurately obtained regardless of the state of the light emitting unit.

Moreover, in addition to said structure, one form of the input system which concerns on this invention is
The light guide member has one side;
The detecting means is preferably provided at least at both ends of the one side of the light guide member.

According to said structure, since the position which captures the light which propagates the inside of a light guide member is the both ends of the said one side, and the said capture positions are comparatively separated, it is possible to detect a position coordinate with high accuracy. it can.

Moreover, in addition to said structure, one form of the input system which concerns on this invention is
It is preferable that an end portion of the light guide member is provided with a conical optical path conversion unit that guides the propagation light to the detection unit.

According to the above configuration, the detection unit can be arranged at a desired position by providing the optical path conversion unit.

For example, the optical path conversion unit (for example, a mirror) is provided in the at least two locations, and the detection unit receives light guided below the upper surface of the light guide member by the optical path conversion unit and photoelectrically converts the light. it can. Assuming this configuration and a configuration without an optical path conversion unit as a comparative configuration, in the configuration without an optical path conversion unit, the light propagated inside the light guide plate expands the area of the upper surface of the light guide plate from the end of the light guide plate. Since it has an optical axis along the direction, it is necessary to cause the image sensor to receive this light as it is. In this case, it is necessary to dispose the imaging element in a direction that increases the area of the upper surface of the light guide plate, and the input device increases in size in a direction that increases the area of the upper surface of the light guide plate. On the other hand, since the light propagating through the inside of the light guide member can be guided below the upper surface of the light guide member with the configuration having the optical path conversion unit as described above, the light receiving unit (detection means) It can arrange | position below and can avoid the enlargement as mentioned above.

Moreover, in addition to said structure, one form of the input system which concerns on this invention is
An image display panel having a plurality of pixels;
It is preferable to drive the pixels of the image display panel based on the position coordinates detected by the detection means.

According to the above configuration, the pixel corresponding to the position coordinate on the image display panel can be driven and viewed.

As described above, according to the present invention, it is possible to realize an input system that has a full flat and simple structure and that is not erroneously recognized even if a hand or the like approaches or touches the surface of the apparatus.

It is a perspective view which shows the structure of the input system of one Embodiment of this invention. FIG. 2 is a cross-sectional view taken along line AA ′ shown in FIG. It is a figure which shows the structure of the pen of the input system of one Embodiment of this invention. It is a figure of the acquired image acquired in the image sensor with which the pen input device of the input system of one embodiment of the present invention was equipped. It is a perspective view which shows the structure of the input system of other embodiment of this invention. It is a top view which shows the structure of a part of input system of other embodiment of this invention. It is a perspective view which shows the one part schematic structure of the input system of other embodiment of this invention. It is a perspective view which shows the structure of a part of input system of other embodiment of this invention. It is a top view which shows the modification of the structure shown in FIG. It is a top view which shows the structure of a part of input system of other embodiment of this invention. It is sectional drawing which shows the one part schematic structure of the input system of other embodiment of this invention. It is a perspective view of the one part structure shown in FIG. 10 and FIG. It is a figure of a conventional structure. It is a figure of a conventional structure. It is a figure of a conventional structure. It is a figure of a conventional structure.

Embodiment 1
An embodiment of an input system according to the present invention will be described with reference to FIGS.

FIG. 1 is a perspective view showing the configuration of the input system of this embodiment, and FIG. 2 is a cross-sectional view taken along line AA ′ shown in FIG.

(Configuration of input system)
As shown in FIG. 1, the input system 50 of the present embodiment includes a pen input device 40 (coordinate input device) and a pen 3 (operation member), and is a touch surface that is the surface of the pen input device 40. When the pen 3 touches (contacts) the (upper surface), the touch position coordinates on the touch surface can be obtained.

● Pen input device 40
As shown in FIG. 1, the pen input device 40 includes a liquid crystal display panel 2 (image display panel), and a rectangular transparent light guide plate 1 (light guide member) disposed on the display surface side of the liquid crystal display panel 2. The transparent light guide plate 1 has imaging units 10 and 20 (detecting means) disposed at both ends of a certain side.

The liquid crystal display panel 2 has a liquid crystal layer sandwiched between a pair of substrates, and each substrate is provided with at least various electrodes for changing the orientation of liquid crystal molecules in 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.

The transparent light guide plate 1 is a single flat plate made of a translucent material. As shown in FIG. 1, the liquid crystal display panel 2 is disposed so as to overlap the display surface side. The size of the transparent light guide plate 1 can be configured substantially the same as that of the liquid crystal display panel. In the present embodiment, as shown in FIG. 1, one side where the imaging units 10 and 20 are disposed is configured to be larger than the liquid crystal display panel 2. Accordingly, at least a part of the imaging units 10 and 20 can be disposed on the back side of the transparent light guide plate 1. Thereby, the enlargement of the size of the direction which spreads along the touch surface of the pen input device 40 is suppressed, and it contributes to realization of a compact size.

The surface of the transparent light guide plate 1 opposite to the liquid crystal display panel 2 is a touch surface touched by the pen 3.

Further, the end portions (corners) where the imaging units 10 and 20 are disposed in the transparent light guide plate 1 are each provided with a concave conical cutout 1a (light path conversion portion). The angle (γ shown in FIG. 2) formed by the conical surface of the notch 1a and the back surface of the transparent light guide plate 1 is 45 degrees or less, and 30 degrees or 45 degrees is selected. A mirror coating 6 (optical path changing portion) is applied to the conical cutout 1a. As a result, as shown in FIG. 2, the optical path of light propagating through the transparent light guide plate 1 and reaching the notch 1a is formed below the transparent light guide plate 1, that is, on the back surface of the transparent light guide plate 1 by the notch 1a. Change towards. Even without the mirror coating 6, the optical path can be changed below the transparent light guide plate 1 by the conical surface of the notch 1 a. That is, the transparent light guide plate 1 does not have to be a perfect quadrangle, and may be a substantial quadrangle such that the corners are notched as described above, or the corners are R-processed.

The thickness of the transparent light guide plate 1 is mainly 1 to 3 mm. As a material of the transparent light guide plate 1, for example, acrylic is used, and polycarbonate or glass may be used. Further, the thickness of the transparent light guide plate 1 is mainly 1 to 3 mm, but it may be thicker than this. In addition, the size of the transparent light guide plate 1 (the size of the touch surface) can be about 1 m square, but is not limited thereto.

The imaging units 10 and 20 are means for detecting propagation light that enters the transparent light guide plate 1 from the light emitting unit 30 of the pen 3 and propagates through the inside of the transparent light guide plate 1. It arrange | positions directly under the notch 1a. In other words, the imaging units 10 and 20 are disposed at two locations separated from each other at the end of the transparent light guide plate 1. In addition, the imaging units 10 and 20 do not protrude above the touch surface of the transparent light guide plate 1. The imaging unit 10 includes a lens 11, a visible light cut filter 12, and an imaging element 13. Similarly, the imaging unit 20 includes a lens 21, a visible light cut filter 22, and an imaging element 23. The imaging units 10 and 20 are connected to the transparent light guide plate 1 and have a structure in which light that does not propagate through the transparent light guide plate 1 is not coupled to the imaging elements 13 and 23.

In this embodiment, the notch 1a is formed in a conical surface shape, but the present invention is not limited to this, and may be formed in a polygonal surface shape.

● Pen 3
On the other hand, the pen 3 corresponding to the pen input device 40 is an operation member called a touch pen or a stylus pen. Details of the pen 3 will be described with reference to FIG.

FIG. 3 is a diagram showing the configuration of the pen 3, and for convenience of explanation, a part of the housing is removed to expose the internal structure. The pen 3 has a light emitting unit 30 that has a light emitting element 31 that emits infrared light and a light guide member 32 that guides the infrared light to the tip of the pen 3, and a power supply device 33. And the control device 34 are stored. As a characteristic configuration of the pen 3 according to the present embodiment, the light emitting unit 30 is disposed at the tip of the pen 3 and the light diffusion member 36 diffuses light on the light emitting side of the light emitting unit 30. There is a point that is attached.

The light diffusing member 36 is made of a resin containing a light diffusing material. Glass beads can be used as the light diffusion material. As the resin, a fluororesin (specifically, polytetrafluoroethylene) and silicon rubber can be used, and it is preferable that the resin is configured to have elasticity. By using the elastic material, when using the transparent light guide plate 1 of the pen input device 40 in contact with the tip of the pen 3, that is, the light diffusing member 36, the surface of the transparent light guide plate 1 is not damaged and is slightly touched by the contact. Since the contact portion is deformed to increase the contact area with the surface of the transparent light guide plate 1, the amount of light coupled to the surface of the transparent light guide plate 1 can be increased.

The light exit surface of the light diffusing member 36 has a taper, more specifically, a curved surface, as shown in FIG. That is, the light diffusing member 36 is generally hemispherical and has a diameter of 2.5 to 5.5 mm. If the diameter is smaller than 2.5, there is a possibility that the sufficiently diffused light cannot be formed, and it is sufficient when the light diffusion member 36 is used in contact with the transparent light guide plate 1 of the pen input device 40. There is a possibility that light that can secure a contact area is not sufficiently coupled to the surface of the transparent light guide plate 1. If the diameter exceeds 5.5 mm, the diffused light may be excessively spread and it may be difficult to accurately detect the position, and the light diffusing member 36 is brought into contact with the transparent light guide plate 1 of the pen input device 40. In this case, since the contact area is too large, the frictional resistance becomes too large and the operability may be impaired. Therefore, if the diameter is 2.5 to 5.5 mm, the position coordinates can be detected with high accuracy while light can be diffused, and a smooth writing feeling (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 tip of the pen 3 and the region that surrounds it.

Further, the curved surface may be provided with a fine uneven shape on the surface. Light can be diffused by the fine unevenness. Further, when the light diffusing member 36 is used in contact with the transparent light guide plate 1 of the pen input device 40, the contact area with the transparent light guide plate 1 is reduced due to the fine unevenness, and the frictional force when sliding is reduced. Therefore, a smooth writing taste (touch feeling) can be realized. In addition, in the case of the aspect which provides the fine unevenness in this way, the light diffusing member 36 is constituted by a resin alone without including the light diffusing material, and the fine unevenness is provided in the region facing the transparent light guide plate 1 in the resin. Also, a light diffusion effect can be achieved. In other words, if the fine irregularities are formed in addition to the light diffusion material, the light diffusion effect can be further enhanced. The fine irregularities can be formed by molding, but are not limited to this method. Although the contact area with the transparent light guide plate 1 is reduced by providing fine irregularities, the reduction of the coupling light amount due to the reduction is about 5%, so that the detection of position coordinates is not greatly affected.

Further, it is preferable that the light emitting surface of the light diffusing member 36 is subjected to wear resistance processing. This is unnecessary when the light diffusing member 36 is made of polytetrafluoroethylene, but when the light diffusing member 36 is made of another material that is not excellent in wear resistance, the light emission It is effective to apply a wear resistant process to the surface. Although there is no restriction | limiting in particular with an abrasion-resistant process, For example, the process which coats the polytetrafluoroethylene on the light-projection surface of the light-diffusion member 36 is mentioned.

Furthermore, the light diffusing member 36 is configured to be detachable from the pen 3. Even if the light diffusing member 36 is damaged for some reason (including deterioration with time), the use of the pen 3 can be continued only by replacing the light diffusing member 36. Compared to the configuration in which the pen 3 is replaced, the use can be continued at a low cost. In order to be detachable, the member on the side to which the light diffusing member 36 is attached (in this embodiment, the light guide member 32) has a groove structure, an occlusal structure, or a portion in contact with the light diffusing member 36, or A fitting structure is provided (not shown), and the light diffusion member 36 is provided with a structure that matches the structure (not shown). In the present embodiment, the light diffusion member 36 is attached to the light guide member 32. However, the present invention is not limited to this, and the light diffusion member 36 may be attached to the housing 35. It may be other embodiments.

The light emitting element 31 may be an LED (light emitting diode) or an LD (laser diode) that emits infrared light. The number of LEDs or LDs is not limited to one provided for one pen 3, and a plurality of LEDs or LDs may be mounted.

Infrared light from the light emitting element 31 that receives light from the power supply device 33 and enters the light diffusing member 36 through the light guiding member 32 enters the light diffusing material 36 and the fine light. Diffusely reflected by unevenness. And it is radiate | emitted as diffused light from the light-projection surface of the light-diffusion member 36. FIG.

The power supply device 33 may be configured to include a battery, for example, or may be configured to be rechargeable.

The control device 34 controls the light emission of the light emitting element 31. For example, a mechanism for emitting light only when the light emitting element 31 comes into contact with the transparent light guide plate 1 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.

As described above, the pen 3 is provided with a light source (light emitting unit) that emits infrared light, and is configured to diffuse and radiate infrared light from the pen tip. When the pen tip of the pen 3 comes into contact with the transparent light guide plate 1, part of the infrared light emitted from the pen tip is coupled to the transparent light guide plate 1 and propagates through the transparent light guide plate 1. Since the pen 3 diffuses and emits infrared light from the pen tip, the light coupled to the transparent light guide plate 1 diffuses and radiates inside the transparent light guide plate 1. Thereby, a position coordinate can be calculated | required accurately.

The imaging units 10 and 20 capture infrared light propagating through the transparent light guide plate 1 (hereinafter referred to as propagation light 4a and 4b), respectively, and from the respective images obtained from the imaging element 13, Find the two-dimensional position coordinates of the contact. The light receiving surface of the image sensor 13 is disposed so as to be parallel to the surface of the transparent light guide plate 1. Hereinafter, the detection principle of pen input will be described in detail.

(Pen input detection principle)
When the pen tip of the pen 3 comes into contact with the touch surface (transparent light guide plate surface) of the pen input device, a part of infrared light emitted from the light pen enters the transparent light guide plate 1 having a refractive index N. Of this incident light, the propagation angle θ _P in the transparent light guide plate 1 is given by the formula:
sin (90 ° −θ _P )> 1 / N
2 is confined in the transparent light guide plate 1 and repeatedly reflected on the front and back surfaces of the transparent light guide plate 1 and travels through the transparent light guide plate 1 as shown in FIG.

Infrared light emitted from the pen 3 is diffused radially around the pen tip and propagates through the transparent light guide plate 1, and some of the light beams 4 a and 4 b are conical surface cutouts 1 a. The image pickup units 10 and 20 receive the reflected light from the end face. Specifically, the reflected light of the end face is collected by the lenses 11 and 21, subsequently passes through the visible light cut filters 12 and 22, and is finally received by the imaging elements 13 and 23. The visible light cut filters 12 and 22 transmit infrared light emitted from the pen and serve to block light in other wavelength bands. Visible light cut filters 12 and 22 block stray light such as sunlight and liquid crystal display panel backlight light, and can increase the SN ratio.

As shown in FIG. 4A, the light emitted from the pen 3 propagates through the transparent light guide plate 1 and the emitted light passes through the lens 11 to form a linear image 15 on the image sensor 13. The position of the linear image 15 changes depending on the position of the pen 3, and by analyzing the acquired image of the imaging unit, angles α and β formed by the light beams 4a and 4b and one side of the transparent light guide plate are obtained, respectively. Using the principle of surveying, the position coordinates of the point where the pen tip serving as the light source contacts is obtained. In FIG. 4A, when the pen is at the position 3a, a linear image 15 is formed. When the pen moves to the position 3b, a linear image 17 is formed.

FIG. 4B shows an acquired image of the image sensor 13. When the pen tip of the pen 3 in the state of irradiating infrared rays is not in contact with the transparent light guide plate 1, nothing appears in the acquired image of the image sensor 13. On the other hand, when the pen tip of the pen 3 in the state of irradiating infrared rays from the light emitting unit comes into contact with the transparent light guide plate 1 and the infrared light is coupled to the transparent light guide plate 1, as shown in FIG. A part of the light beam 4a is guided to the imaging device 13, a linear image is formed on the imaging surface of the imaging device 13, and the linear image 15 appears on the acquired image.

The position of the linear image 15 shown in FIG. 4 changes depending on the position of the contact point of the pen tip of the pen 3, and when the position of the contact point of the pen tip is changed, the linear image is a line indicated by a broken line. It changes like the image 17. The locus of the linear image is a fan shape 16 indicated by a one-dot chain line. The rotation angle α ₁ ′ of the line segment connecting the fan-shaped center and the line image (with the center of the arc as the rotation center) is the line segment connecting the pen 3 and the image sensor 13 and the certain side of the transparent light guide plate 1. The angle is the same as the angle α ₁ formed by. Alpha _{1 'is} found, alpha _1' from the acquired image of the imaging element alpha ₁ is obtained from. Similarly, when the pen is moved to the position of the 3b, formed a line-shaped image 17, by obtaining the inclination alpha _{2 'of} the line-shaped image 17, alpha ₂ is calculated.

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 pen 3 and the image sensor 23 and the certain side of the transparent light guide plate 1 is obtained.

Then, when the interval between the image sensors is L, the displacement angle of the bright spot obtained by reading the image from the image sensor 13 is α, and the displacement angle of the bright spot obtained by reading the acquired image from the image sensor 23 is β, 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) (2)
Satisfied. Solving this, the coordinates (X, Y) of the bright spot are
X = tan β · L / (tan α + tan β) (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 by α and β obtained as described above and L that can be obtained in advance. Among these, L is an interval between the image sensor 13 and the image sensor 23 and is a fixed value. By obtaining α and β, pen input coordinates X and Y (position coordinates) can be obtained.

Note that the interval L between the image pickup elements is a distance between the optical axis center of the lens 11 and the optical axis center of the lens 21.

In order to obtain the position coordinates of the pen 3 by the above method, the input system 50 is provided with a position coordinate detector (not shown). The position coordinate detection unit can be provided in the pen input device 40.

Further, based on the position coordinates of the pen 3 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 pen 3. Is possible. For this purpose, if a control unit (not shown) that controls the driving of the liquid crystal display panel 2 acquires information on the position coordinates obtained by the position coordinate detection unit and drives the liquid crystal display panel 2 based on the information. Good.

(Operational effect of this embodiment)
As described above, the input system 50 according to the present embodiment can obtain the position coordinates of the pen 3 by capturing the propagated light at at least two positions apart from each other at the end of the transparent light guide plate 1. That is, the total number of image sensors may be two, that is, the image sensor 13 and the image sensor 23 as shown in FIG. Therefore, it is not necessary to arrange an image sensor in each light guide region as in Patent Document 1, and the apparatus is not complicated and large, and the cost is not increased.

Further, according to the above configuration, the transparent light guide plate is a single simple plate, and the complicated light guide cost as in Patent Document 1 is not required.

Further, according to the configuration of the pen input device 40 of the present embodiment, since the imaging elements 13 and 23 are provided at positions that do not protrude upward from the touch surface of the transparent light guide plate 1, the touch surface of the transparent light guide plate 1 is It becomes the uppermost surface of the pen input device 40, and the image sensor does not protrude above the touch surface. Therefore, even when the pen input device 40 of the input system 50 of this embodiment is applied to a table type terminal, the table surface can be made completely flat without the surroundings rising like a bank.

In addition, the input system 50 according to the present embodiment is not a light shielding method, but has a configuration in which light that has propagated inside the light guide plate is received by the imaging device, so that there is no possibility of erroneous recognition due to stray light including sunlight. Accurate position detection can be realized, and therefore it is possible to place the device outdoors or near a window.

Further, the pen input device 40 of the input system 50 according to the present embodiment includes light that does not propagate through the transparent light guide plate 1 because the imaging units 10 and 20 that receive the light emitted from the tip of the pen 3 are connected to the transparent light guide plate 1. Has a structure that is not coupled to the imaging elements 13 and 23. Therefore, even if illumination light is applied from the normal direction of the touch surface of the transparent light guide plate 1, since the light is not coupled to the transparent light guide plate 1, stray light is not guided to the imaging elements 13 and 23. For this reason, the pen input device 40 is not easily affected by external light, and can be disposed outdoors or near a window.

Further, according to the above configuration, since two-dimensional position coordinates can be obtained from each image, it is not necessary to prepare a plurality of light guide plates in order to obtain two-dimensional position coordinates as in Patent Document 1, This can contribute to downsizing of the apparatus.

From the above, the present invention having the above-described configuration provides a highly versatile input system that realizes a full flat coordinate input device and that is not erroneously recognized even if a hand touches the surface of the device. be able to.

In addition, although this embodiment demonstrated the structure using the image pick-up element 13 and the image pick-up element 23 in total, this invention is not limited to this, Each in the edge part of the transparent light-guide plate 1 is not limited to this. You may collect in one image pick-up element using a mirror and a shutter from a part.

In this embodiment, the configuration using one pen 3 has been described. However, the present invention is not limited to this, and even when a plurality of pens are used, for example, the light emission timing of each pen. If a plurality of pens are in contact with the touch surface of the transparent light guide plate 1 at the same time, the respective position coordinates can be obtained.

In the present embodiment, the configuration in which light is acquired from both ends of one side of the transparent light guide plate 1 has been described. However, the present invention is not limited to this, and the light is acquired from two different locations on the one side. It is good also as composition to do.

In addition, in the present embodiment, the configuration in which light is acquired from both ends of one side of the transparent light guide plate 1 has been described. However, the present invention is not limited to this, and each of the two adjacent sides of the transparent light guide plate 1 is provided. Locations for acquiring light may be provided, and the position coordinates of the pen 3 may be obtained from the distance between the locations and an image obtained from each location.

In the present embodiment, the light emitted from the tip of the pen 3 is configured to diffuse by the light diffusion member 36 provided at the tip of the pen 3. Thereby, a sufficient amount of light can be coupled to the transparent light guide plate 1 without depending on the inclination angle of the pen 3. Therefore, accurate position detection can be realized.

[Embodiment 2]
Another embodiment of the present invention will be described. In addition, in this embodiment, in order to demonstrate a difference from the said Embodiment 1, for convenience of explanation, the same member number is attached | subjected to the member which has the same function as the member demonstrated in Embodiment 1, and the description Is omitted.

Another embodiment of the input system of the present invention will be described with reference to FIG. FIG. 5 is a perspective view showing the configuration of the input system of this embodiment. The difference between this embodiment and the above-mentioned Embodiment 1 exists in the structure of the both ends of a certain side of the transparent light-guide plate 1. FIG.

Specifically, in Embodiment 1, the mirror coating 6 is applied to the conical surface of the cutout 1a of the transparent light guide plate 1. On the other hand, in the input system of the present embodiment, the notch 1a ′ of the transparent light guide plate 1 of the pen input device 40 ′ (coordinate input device) forms an angle perpendicular or substantially perpendicular to the back surface of the transparent light guide plate 1. A cylindrical surface is formed, and the cylindrical surface of the notch 1a 'is not mirror-coated. Instead, mirror elements 14 and 24 are disposed adjacent to the notch 1a'. Is different.

That is, the end surface of the transparent light guide plate 1 is processed so as to be provided with an arc-shaped notch as in the first embodiment, but unlike the first embodiment, it has a vertical surface.

The imaging unit 10 ′ includes a mirror element 14, a lens 11, a visible light cut filter 12, and an imaging element 13. The imaging unit 20 ′ has a mirror element 24, a lens 21, a visible light cut filter 22, and an imaging element 23.

The mirror elements 14 and 24 include cylindrical surfaces 14b and 24b and conical surfaces 14a and 24a, and the conical surfaces 14a and 24a are mirror-coated.

The light beam propagating through the transparent light guide plate 1 and guided to the four corners of the light guide plate is transmitted through the notch 1 a ′ having the concave cylindrical surface of the transparent light guide plate 1 and emitted from the transparent light guide plate 1. , 24 are guided to the conical surfaces 14 a, 24 a and reflected by the conical surfaces 14 a, 24 a are guided toward the back surface of the transparent light guide plate 1. Thereafter, the light is condensed by the lenses 11 and 12, passed through the visible light cut filters 12 and 22, received by the image sensors 13 and 23, and the same method as that of the first embodiment described above from the inclination angle of the linear image of the photographed image. Thus, the azimuth angles α and β of the luminous flux are obtained.

It is assumed that the size of the transparent light guide plate 1 is as large as about 1 m square. In this case, as in the first embodiment, it is difficult to perform mirror coating on the conical surfaces at the four corners of the transparent light guide plate 1 in terms of the process, resulting in high cost. On the other hand, by providing the mirror elements 14 and 24 separately as in the present embodiment, it is only necessary to apply a mirror coating to the conical surfaces of the mirror elements 14 and 24 that are much smaller than the transparent light guide plate 1, and the work is easy. In addition, since a large number of optical elements can be mirror-coated at the same time, the cost of the mirror element can be reduced. In addition, by using a mirror element having a conical surface as a mirror, light utilization efficiency can be improved by reflecting light that is refracted on the conical surface and emitted to the outside of the light guide plate and guiding it to the imaging unit side.

[Embodiment 3]
Another embodiment of the present invention will be described. In addition, in this embodiment, in order to demonstrate a difference from the said Embodiment 1, for convenience of explanation, the same member number is attached | subjected to the member which has the same function as the member demonstrated in Embodiment 1, and the description Is omitted.

Another embodiment of the input system of the present invention will be described with reference to FIGS.

FIG. 6 is a diagram showing another form of the transparent light guide plate 1 provided in the pen input device 40 provided in the input system of the present embodiment. FIG. 7 is a perspective view schematically showing the arrangement of the transparent light guide plate 1 and the imaging unit 10 provided in the pen input device 40.

The transparent light guide plate 1 of the present embodiment is provided with a notch 1a ″ at a position inside the end portion of the transparent light guide plate 1. As shown in FIG. 6, the notch 1 a ″ has a funnel-like structure formed in the transparent light guide plate 1. The notch 1a ″ forms a hole 1b penetrating the back surface of the transparent light guide plate 1 at the conical tip.

Further, as shown in FIG. 7, the notch 1a ″ is fitted with a light shielding member 60 having a conical shape and having a hole at the tip thereof, and external light is provided in the notch 1a ″. Is configured to prevent intrusion. In addition, the surface of the light shielding member 60 facing the notch 1a ″ is configured to reflect light.

Then, the light propagating through the transparent light guide plate 1 reaches the notch 1 a ″, converts the optical path, is guided below the back surface of the transparent light guide plate 1 from the vicinity of the hole 1 b, and enters the imaging unit 10. It has a configuration. In the present embodiment, for convenience of explanation, the description of the other imaging unit 20 described in the first embodiment is omitted, but light also enters the imaging unit 20 in the same manner as in the present embodiment. Can be configured.

[Embodiment 4]
Another embodiment of the present invention will be described. In addition, in this embodiment, in order to demonstrate a difference from the said Embodiment 1, for convenience of explanation, the same member number is attached | subjected to the member which has the same function as the member demonstrated in Embodiment 1, and the description Is omitted.

Referring to FIGS. 8 and 9, another embodiment of the present invention will be described as follows.

The pen input device 40 provided in the input system of the first embodiment is provided with two imaging units 10 and 20 as detection means, whereas in this embodiment, as shown in FIG. The difference is that three imaging units 10, 20, and 70 (detecting means) are provided.

By providing this configuration, as shown in FIG. 8, even if there are two pens 3A and 3B (operation members) as detection objects, the coordinate position of each pen can be detected. .

For example, suppose that only two imaging units are provided, the traveling direction of the propagation light of one of the two pens 3A and 3B (the optical path of the propagation light toward the imaging unit) and the propagation light of the other pen When the traveling directions overlap, the linear images also overlap, so it is not possible to specify which of the two pens 3A and 3B is in front. However, in this embodiment, as shown in FIG. 8, if there are three imaging units 10, 20, and 70 as light receiving means, the imaging unit 10 with two optical paths that do not overlap each pen 3 A and 3 B. It becomes possible to obtain the contact positions of the pens 3A and 3B using 20 and 70. The imaging unit 70 is the same as the imaging units 10 and 20 and includes a unit lens 71, a visible light cut filter 72, and an imaging element 73.

Specifically, for example, in FIG. 8, if the pen 3B is present at point P _3, overlaps the optical path of the pen 3B pen 3A to the imaging unit 10. In this case, two imaging units 20 and 70 are used to detect the pen 3A, while the imaging units 10 and 70 are used to detect the pen 3B. As a result, the optical paths do not overlap.

Therefore, regardless of the location of the two pens 3A and 3B on the transparent light guide plate 1, the position coordinates of the contact points of the pens 3A and 3B can be reliably specified.

In general, when there are M pens 3 as objects to be detected, the number N of necessary detection means is:
N = M + 1
It becomes.

Further, when at least three image pickup units 10, 20, and 70 are provided as detection means, there are the following merits.

That is, when there are two imaging units, there is a possibility that when the pen is brought into contact with the vicinity of the side of the transparent light guide plate 1 provided with the two imaging units, it becomes a blind spot and cannot be detected by the two imaging units. In this case, if there are three imaging units, for example, if they are arranged at the vertices of a triangle, the pen can be touched anywhere on the transparent light guide plate 1 without generating a blind spot. The position coordinates of the contact point of the pen can be reliably specified.

Thus, in the present embodiment, three imaging units are provided. Thus, for each of the two pens, the contact position of each pen can be obtained using the combination of the imaging unit 20 and the imaging unit 70 by the two optical paths that do not overlap and the combination of the imaging unit 10 and the imaging unit 70. It becomes possible. In addition, by arranging three imaging units at the apexes of the triangle, the position coordinates of the contact point of the pen can be ensured regardless of where the pen touches the transparent light guide plate 1 without generating a blind spot. It becomes possible to specify.

(Modification)
In the present embodiment, the configuration including three imaging units has been described, but the present invention may include four or more imaging units.

When four image pickup units are provided, for example, as shown in FIG. 9, it may be arranged at the four corners of the transparent light guide plate 1. Even when four imaging units are provided, the input from the two pens can be accurately detected as in the present embodiment.

In this modification, for example, when detecting one pen, any two of the four imaging units 10, 20, 70, and 80 can be used. This is because, for example, when only two imaging units are arranged along one side of the transparent light guide plate 1, the signal quality may be degraded when the pen contact point is far from these imaging units. is there. Therefore, by disposing the imaging units at the four corners of the transparent light guide plate 1 as in this modification, when the contact point of the pen 3 is far from the imaging units 10 and 20, the imaging units 70 and By detecting at 80, the signal quality can be detected without causing deterioration.

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.

[Embodiment 5]
Another embodiment of the present invention will be described. In addition, in this embodiment, in order to demonstrate a difference from the said Embodiment 1, for convenience of explanation, the same member number is attached | subjected to the member which has the same function as the member demonstrated in Embodiment 1, and the description Is omitted.

Another embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 10, the pen input device 40 ″ provided in the input system 50 ′ of the present embodiment includes an optical member 90 (optical path conversion unit) that is closely fixed to the back surface of the transparent light guide plate 1 ′. And the pen input device 40 of the first embodiment are different in that the shape of the transparent light guide plate 1 ′ is different. In the pen input device 40 ″ of the present embodiment, the imaging units 10 and 20 are disposed at positions where light is emitted from the optical member 90.

Further, the pen input device 40 ″ of the present embodiment allows a part of the propagation light propagating through the transparent light guide plate 1 ′ to be transmitted from the back surface of the transparent light guide plate 1 ′ by the optical member 90 described later from the back surface of the transparent light guide plate 1 ′. Also take down. Therefore, it is not necessary to provide a notch in the light guide plate as in the first embodiment. That is, the transparent light guide plate 1 ′ only needs to have a configuration (structure) capable of propagating light therein, and does not require any other processing.

The optical member 90 is a translucent material disposed between the back surface of the transparent light guide plate 1 ′ and the imaging units 10 and 20 described later.

11 is a cross-sectional view taken along line AA ′ shown in FIG. FIG. 12 is a view showing the outer shape of the optical member 90,
The optical member 90 has a flat upper surface (adjacent surface), and is bonded and fixed to the back surface of the transparent light guide plate 1 'as shown in FIG. The optical member 90 takes out the light propagating through the transparent light guide plate 1 ′ from the back surface of the transparent light guide plate 1 ′, enters the extracted light into itself and couples it inside, and propagates through the inside. It is the composition which makes it. The bonding method between the optical member 90 and the transparent light guide plate 1 ′ is not particularly limited. However, as described above, the optical member 90 takes out light from the transparent light guide plate 1 ′ and makes it incident, so this is not hindered. Adhering and fixing using a method or material.

The optical member 90 is made of a material having the same or higher refractive index than the transparent light guide plate 1 ′. This prevents light propagating through the transparent light guide plate 1 ′ from being reflected at the boundary surface between the optical member 90 and the transparent light guide plate 1 ′ and returning again to the inside of the transparent light guide plate 1 ′. The extraction efficiency of light from ′ can be increased. In this embodiment, since the transparent light guide plate 1 ′ is made of glass, the optical member 60 is made of high refractive index glass or polycarbonate having a higher refractive index than glass. Thereby, it is possible to efficiently extract light from the transparent light guide plate 1 ′ and to enter the optical member 90.

In addition, as mentioned above, since this invention can comprise a transparent light-guide plate from materials other than glass, when a transparent light-guide plate is an acrylic, for example, an optical member is acrylic, high refractive index glass, polycarbonate similarly. It can consist of

In this embodiment, the optical member 90 is made of a material having a refractive index higher than that of the transparent light guide plate 1 ′. However, the light propagating through the transparent light guide plate 1 ′ is the optical member 90 and the transparent light guide plate 1. And the optical member 90 may be made of a material having the same refractive index as that of the transparent light guide plate 1 ′. .

As shown in FIGS. 2 and 3, the optical member 90 is provided with a concave conical cutout 90a in a region near the corner of the transparent light guide plate 1 ′ on the end surface adjacent to the upper surface. The angle (γ shown in FIG. 2) formed by the conical surface of the notch 90a and the back surface of the optical member 90 is 45 degrees or less, and 30 degrees or 45 degrees is selected. The conical cutout 90a may be provided with a mirror coating (optical path changing portion).

Then, as shown in FIG. 11, the light propagating through the optical member 90 and reaching the notch 90a changes its optical path toward the lower side of the optical member 90, that is, toward the back surface of the optical member 90 by the notch 90a. Let That is, the light propagating through the transparent light guide plate 1 ′ travels downward from the lower surface of the transparent light guide plate 1 ′.

In the present embodiment, the cutout 90a is formed in a conical surface shape, but the present invention is not limited to this, and may be formed in a hyperboloid shape or a polygonal surface shape.

In this embodiment, the shape of the optical member 90 is similar to a fan shape as shown in FIG. 12 when viewed from the upper surface side, but is not limited to this.

The manufacturing method of the optical member 90 is not particularly limited, but can be manufactured at low cost by plastic molding or glass molding.

The optical member 90 is disposed on the back surface in the vicinity of two adjacent corners of the four corners of the rectangular transparent light guide plate 1 ′ as shown in FIG. The arrangement position of the optical member 90 is not limited to this. Since the two imaging units 10 and 20 are arranged apart from each other in order to realize a detection method described later, the light is propagated through the transparent light guide plate 1 ′ corresponding to the arrangement position of the imaging units 10 and 20. The optical member 90 may be arranged in the middle of the light path where light finally enters each imaging unit.

The imaging units 10 and 20 are disposed immediately below the conical surface notch 90a of the optical member 90, and are disposed at two positions apart from each other at the end of the transparent light guide plate 1 ′. Further, the imaging units 10 and 20 do not protrude above the touch surface of the transparent light guide plate 1 ′. The imaging units 10 and 20 have a structure in which light that does not propagate through the transparent light guide plate 1 ′ is not coupled to the imaging elements 13 and 23.

As mentioned above, although embodiment which concerns on this invention was described, this invention is not limited to said embodiment. Various modifications can be made within the scope of the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention.

The present invention can be provided for any type of input system that uses a light emitting pen to determine the coordinate position of the pen.

1, 1 'transparent light guide plate (light guide member)
1a, 1a ′, 1a ″ Notch (optical path conversion unit)
1b Hole 2 LCD panel (image display panel)
3, 3A, 3B pen (light emitting part)
4a, 4b Luminous flux 6 Mirror coating (optical path conversion unit)
10, 20, 10 ', 20', 70, 80 Imaging unit (detection means)
DESCRIPTION OF SYMBOLS 11, 21 Lens 12, 22 Visible light cut filter 13, 23 Imaging element 14, 24 Mirror element 14a, 24a Conical surface 14b, 24b Cylindrical surface 15 Linear image 16 Fan shape 17 Linear image 30 Light emission part 31 Light emitting element 32 Light guide member 33 Power supply device 34 Control device 35 Housing 36 Light diffusing member 40, 40 ', 40 "Pen input device (input device)
50 Input system 60 Light shielding member 90 Optical member 90a Notch

Claims (5)

1. A light guide member;
   An operation member having a light emitting portion for making light incident on the light guide member by contacting the light guide member;
   At least two detection means that are located at positions that do not protrude above the upper surface of the light guide member and that are separated from each other. The at least two detecting means for detecting propagating light propagating through the inside of the optical member,
   The input system is characterized in that the detection means detects a traveling direction of the propagation light from the detected propagation light, and a position coordinate of a point where the light emitting unit contacts the light guide member.
2. 2. The input system according to claim 1, wherein the light is diffused and radiated to the light guide member when the light emitting unit comes into contact with the light guide member.
3. The light guide member has one side;
   The input system according to claim 1, wherein the detection unit is provided at least at both ends of the one side of the light guide member.
4. The input system according to any one of claims 1 to 3, wherein a conical optical path conversion unit that guides the propagation light to the detection means is provided at an end of the light guide member.
5. An image display panel having a plurality of pixels;
   5. The input system according to claim 1, wherein the pixel of the image display panel is driven based on the position coordinates detected by the detection unit.

Images