JP5944255B2 - Operation member having light emitting unit and coordinate input system having the same - Google Patents

Description

  The present invention relates to an operation member having a light emitting unit and a coordinate input system including the operation member.

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

  In the coordinate input system, the coordinate input device or the position detection device obtains the coordinates of the approached or touched position of the pen or finger by causing the pen or finger to approach or contact the coordinate input area of the coordinate input device. The obtained coordinates are for displaying an object such as a point image or a straight line image on a display screen such as a liquid crystal display separate from the coordinate input device or a liquid crystal panel integrally laminated on the coordinate input device. Used for etc.

  For example, the touch panel 100 disclosed in Patent Document 1 includes a light guide plate 101, a light source 102 that makes light incident on the light guide plate 101, and a light guide plate 101, as shown in FIGS. The light from the light source 102 scattered by the detection object 110 between the light receiving elements 104 and 105 disposed on a part of the side surface of the light guide plate 101 and the light receiving elements 104 and 105 between the side surface of the light guide plate 101 and the light receiving elements 104 and 105 And an image forming means 107 for forming an image. Further, the light absorbing means 108 is disposed on the side surface of the light guide plate 101 on which the light receiving elements 104 and 105 are disposed. The light receiving elements 104 and 105 are located outside the irradiation range of the light source 102 as shown in FIG. Is arranged.

  The information input device 200 disclosed in Patent Document 2 includes a coordinate input system using a stylus pen. Specifically, the information input device 200 includes a backlight 210, a liquid crystal panel 220, and a stylus pen 230, as shown in FIG. The backlight 210 includes a light source 211 that emits IR light (infrared light), and a light guide plate 212 that converts light emitted from the light source 211 into planar light. The liquid crystal panel 220 includes a TFT array substrate 201, a color filter substrate 222, and a liquid crystal layer 223 sandwiched by both substrates. A light receiving element 224 is disposed on the surface of the TFT array substrate 201 on the liquid crystal layer 223 side. The stylus pen 230 is composed of a pen tip 233 and a body 235 in appearance. The pen tip portion 233 includes a reflection portion 234 extending in a rod shape from the end surface of the body 235 along the center axis of the pen.

  In the information input device 200, infrared light mixed with visible light is emitted from the backlight 210 to the liquid crystal panel 220 and emitted from the display surface 220 </ b> A of the liquid crystal panel 220. Of the light emitted from the display surface 220 </ b> A, infrared light is reflected by the reflecting portion 234 of the stylus pen 230. The reflected light then enters the liquid crystal panel 220 again and is detected by the light receiving element 224, whereby the touch position of the stylus pen 230 can be detected.

  A touch pad 300 disclosed in Patent Document 3 includes a coordinate input system using a light-emitting pen 301 having a light-emitting unit. Specifically, as shown in FIG. 11, the touch pad 300 includes a screen cover 302 (so-called light guide plate) made of a relatively hard material and a screen cover 303 (also called an elastic member) made of a relatively soft material. I can say). Then, the light-emitting pen 301 comes into contact with the screen cover 303. In the touch pad 300, the incident positions of the screen covers 302 and 303 by the light-emitting pen 301 (positions touched by the light-emitting pen 301) are detected by the triangulation method.

JP 2009-258967 A (published November 5, 2009) JP 2010-26693 A (released February 4, 2010) Special table 2005-520239 gazette (published July 7, 2005)

  In the technique of Patent Document 3, the screen cover 303 as an elastic member is made of a light transmitting material. When the light-emitting pen 301 comes into contact with the screen cover 303, a small dent 304 is formed. The recess 304 acts like a wide-angle lens so that light emitted from the light-emitting pen 301 enters the screen cover 302. Therefore, the light from the light-emitting pen 301 cannot be sufficiently scattered at the touch position unless the light-emitting pen 301 is pressed against the screen cover 303 so that the recess 304 is formed. For this reason, the amount of light incident on the screen cover 302 varies greatly depending on the inclination of the light-emitting pen 301 at the time of touch. As a result, the technique of Patent Document 3 has a problem that signal quality deteriorates.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is an operation member having a light emitting unit and used as an input unit to a coordinate input device, and having a signal quality by light emission. An object is to provide a good operation member and a coordinate input system including the same.

  In order to solve the above-described problem, an operation member of the present invention is an operation member that includes a light source and couples light from the light source to a light guide plate provided in the input device. An elastic member that is deformed by contact with the light guide plate is provided, and a light scattering region that scatters light is formed on the elastic member.

  In order to optically couple the light emitted from the light source of the operation member to the light guide plate provided in the input device and propagate the light into the light guide plate, it is necessary to make the light incident on the light guide plate at an incident angle of the total reflection condition. Since the configuration of a normal light source is configured to radiate light having a specific directivity, it is difficult to efficiently cause the emitted light to enter the light guide plate at an incident angle under total reflection conditions. Therefore, according to the above configuration, an elastic member that is deformed by contact with the light guide plate is provided at a light emission position of the light source, and a light scattering region that scatters light is formed on the elastic member. Yes.

  As a result, the light emitted from the light source is scattered in the light scattering region formed on the elastic member, and enters the light guide plate as light having a wide directivity. For this reason, the amount of light incident on the light guide plate at the incident angle of the total reflection condition increases, and the optical coupling efficiency with the light guide plate of the input device increases.

  The elastic member is deformed when the operating member comes into contact (touch) with the light guide plate, and the area of the contact surface increases. And the light scattered by the light-scattering area | region of an elastic member becomes easy to inject into the inside of a light-guide plate through the said contact surface. For this reason, the optical coupling efficiency with the light guide plate of the input device is further increased.

  From the above, according to the above configuration, it is possible to realize an operation member with good signal quality by light emission.

  In the operation member of the present invention, the light source includes a light emitting element and a sealing resin portion that seals the light emitting element, and light from the light emitting element is provided on the side surface of the light source to the light emitting position. It is preferable that a reflecting portion for guiding is provided.

  According to the above configuration, the side surface of the light source is provided with the reflection portion that guides the light from the light emitting element to the light emitting position, so that the light emitted from the light emitting element has a wide radiation angle and is a light source. The light component that reaches the side surface of the light source is guided in the light emission direction of the light source (the direction of the scattering unit) by the reflection unit. Therefore, according to the above configuration, the loss of light rays can be eliminated and the amount of light rays guided to the scattering portion side can be increased, so that the light utilization efficiency can be further improved.

  Moreover, it is preferable that the operation member of the present invention includes an inclination angle holding member that keeps the inclination angle of the tip portion with respect to the light guide plate constant.

  According to the above configuration, since the tilt angle holding member that keeps the tilt angle of the tip portion with respect to the light guide plate constant is provided, the operation member does not touch the light guide plate at the tip portion with various tilt angles. It will be touched at a certain tilt angle. For this reason, the formation part of a scattering part can be set so that it may optically couple with a light guide plate with respect to the emitted light of the light source inclined by the inclination angle hold | maintained by the inclination suppression member. Therefore, as compared with the case where the operation member is touched to the light guide plate at various inclination angles, the formation region of the scattering portion can be narrowly limited.

  In the operation member of the present invention, the elastic member preferably contains a light scatterer.

  As a result, since the light emitted from the light source is scattered even inside the elastic member, the amount of light incident on the light guide plate at the incident angle under the total reflection condition is further increased, and the optical coupling efficiency with the light guide plate of the input device is increased. It gets even higher.

  In the operation member of the present invention, it is preferable that the light source is disposed at a tip portion, and the light emitting element is an LED.

  According to said structure, since the said light source is arrange | positioned at the front-end | tip part and the said light emitting element is LED, in order to propagate the light radiated | emitted from a light source, it becomes unnecessary to provide a light guide member separately, The number of parts can be reduced.

  In the operation member of the present invention, it is preferable that a sliding member is provided on a contact surface of the elastic member with the light guide plate.

  According to said structure, since the sliding member is provided in the contact surface with the said light-guide plate in the said elastic member, the slidability between a light-guide plate and an operation member is improved, and smooth writing (touch) Sensation) can be realized, and the light coupling efficiency with the light guide plate can be improved by the light scattering region formed in the elastic member.

  In order to solve the above-described problem, the coordinate input system of the present invention includes a light guide plate, the above-described operation member, at least two light receiving units that receive propagating light propagating in the light guide plate, and the light guide plate. Detection means for obtaining coordinates of a contact position of the operation member 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 when the operation member is brought into contact with the surface; It is characterized by having prepared.

  Thereby, a coordinate input system with good signal quality can be realized.

  As described above, the operation member of the present invention includes a light source, and is an operation member that couples light from the light source to a light guide plate provided in the input device. The elastic member which deform | transforms by contact with is provided, The light-scattering area | region which scatters light is formed in the said elastic member.

  In addition, as described above, the coordinate input system of the present invention includes the light guide plate, the operation member, at least two light receiving units that receive the propagation light propagating through the light guide plate, and the surface of the light guide plate. A detecting unit that obtains coordinates of a contact position on the surface of the light guide member in the operation member based on an output of the light receiving unit that detects propagation light based on the contact when the operation member is contacted; It is.

  Therefore, it is possible to realize an operation member that has a light emitting unit and is used as an input means to the coordinate input device and has a good signal quality by light emission, and a coordinate input system including the operation member. .

It is a perspective view which shows the structure of the coordinate input system of one Embodiment of this invention. It is arrow sectional drawing of the cutting line A-A 'shown in FIG. (A) is sectional drawing which shows one structural example of the pen shown in FIG. 1, (b) is an expanded sectional view which shows the structure of a front-end | tip part. It is sectional drawing which showed typically the structure of the light source which is one of the characteristic parts of a pen. (A) is sectional drawing which showed typically the schematic structure of the pen as the modification 1, (b) is sectional drawing which showed the schematic structure of the pen as the modification 2 typically. It is sectional drawing which showed the structure of the front-end | tip part in the pen as the modification 3. (A) is a perspective view which shows the imaging condition in the imaging unit in the said coordinate input system, (b) is a top view which shows the image in the imaging device of the said imaging unit. It is a perspective view which shows the structure of the coordinate input system of other embodiment of this invention. (A) is a perspective view which shows the structure of the position detection apparatus as a coordinate input device of patent document 1, (b) is a top view which shows the structure of the principal part of the position detection apparatus of (a). It is sectional drawing which shows the structure of the information input device of patent document 2, and a perspective view which shows the structure of a stylus pen. It is sectional drawing which shows the whole structure of the touchpad currently disclosed by patent document 3, and an expanded sectional view which shows the structure of the touch position vicinity of a pen.

  One embodiment of the operating member and coordinate input system of the present invention will be described with reference to FIGS. Hereinafter, an embodiment of the coordinate input system of the present invention will be mainly described, and an embodiment of the operation member of the present invention will be described therein.

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

(Configuration of coordinate input system)
As shown in FIG. 1, the coordinate input system 50 of the present embodiment includes a pen input device 40 (coordinate input device) and a pen 3 (operation member). When the pen 3 touches (contacts) the touch surface which is the surface of the pen input device 40, two-dimensional touch position coordinates 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), a rectangular light guide plate 1 (light guide member) disposed on the display surface side of the liquid crystal display panel 2, and The 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 alignment 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.

  The 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 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 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 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) of the light guide plate 1 where the imaging units 10 and 20 are disposed 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 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. Thereby, as shown in FIG. 2, the optical path of the light propagating through the light guide plate 1 and reaching the notch 1a is changed by the notch 1a toward the lower side of the light guide plate 1, that is, toward the back surface of the light guide plate 1. Let Even without the mirror coating 6, the optical path can be changed below the light guide plate 1 by the conical surface of the notch 1 a. That is, the light guide plate 1 does not have to be a perfect quadrangle, and may be a substantial quadrangle in which corners are cut out as described above, or corners are rounded.

  The thickness of the light guide plate 1 is mainly 1 to 3 mm. As the material of the light guide plate 1, for example, acrylic is used, and polycarbonate or glass may be used. Further, the thickness of the light guide plate 1 is mainly 1 to 3 mm, but it may be thicker than this. In addition, the size of the 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 disposed directly below the conical cutout 1 a of the light guide plate 1. In other words, the imaging units 10 and 20 are disposed at two locations separated from each other at the end of the light guide plate 1. Further, the imaging units 10 and 20 do not protrude above the touch surface of the 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 light guide plate 1 and have a structure in which light that does not propagate through the light guide plate 1 is not coupled to the imaging elements 13 and 23.

  In the present embodiment, the notch 1a 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.

(Pen 3)
The pen 3 is an operation member called a so-called touch pen or stylus pen. The detailed configuration of the pen 3 will be described in detail below. FIG. 3A is a cross-sectional view showing a configuration example of the pen 3, and FIG. 3B is an enlarged cross-sectional view showing the configuration of the tip portion of the pen 3.

  As shown in FIG. 3A, the pen 3 includes a light source 31, a drive device 32, a power supply device 33, an elastic member (scattering part) 34 ′, and a housing 35. A part of the light source 31, the drive device 32, and the power supply device 33 are stored in the housing 35.

  The light source 31 is a resin-sealed package in which a light-emitting element is sealed with resin, and emits light having a wavelength in the visible region to the infrared region. The light source 31 is disposed at the tip portion of the pen 3. Accordingly, since the light emitted from the light source 31 is propagated, it is not necessary to provide a separate light guide member, and the number of components can be reduced. A specific configuration of the light source 31 will be described later.

  The drive device 32 and the power supply device 33 function as a control unit that controls light emission of the light emitting element provided in the light source 31. The drive device 32 includes a drive circuit that drives light emission of the light emitting element. The power supply device 33 is a device that supplies power to the drive device 32. The power supply device 33 can be configured to incorporate a battery, for example. Alternatively, it can be rechargeable. The control unit including the drive device 32 and the power supply device 33 includes a mechanism in which the light source 31 emits light only when the tip of the pen 3 comes into contact with the light guide plate 1, for example. This mechanism can be configured by using a pressure-sensitive switch or the like, and the light emission time can be controlled. For this reason, power consumption can be reduced and battery life can be extended.

  One of the characteristic configurations of the pen 3 of the present embodiment is the configuration of the light source 31. FIG. 4 is a cross-sectional view schematically showing the configuration of the light source 31 that is a characteristic part of the pen 3.

  As shown in FIG. 4, the light source 31 is in the form of a sealing resin package including a light emitting element 31a and a sealing resin portion 31b for sealing the light emitting element 31a. Further, the portion on the light guide plate 1 side in the sealing resin portion 31b has a hemispherical curved surface. Moreover, as the light emitting element 31a, LED (Light Emitting Diode), LD (Laser Diode), etc. are mentioned. In particular, the light emitting element 31a is preferably an LED.

  By the way, in order to optically couple the light emitted from the light source 31 of the pen 3 to the light guide plate 1 and propagate the light into the light guide plate 1, it is necessary to make the light incident on the light guide plate 1 at an incident angle of the total reflection condition. Since the configuration of the normal light source 31 is configured to radiate light having a specific directivity, it is difficult to efficiently make the emitted light incident on the light guide plate 1 at an incident angle of the total reflection condition. . Therefore, in the pen 3, a scattering unit 34 that scatters light emitted from the light source 31 is provided at the light emission position of the light source 31.

  According to this configuration, light emitted from the light source 31 is scattered by the scattering portion 34 and enters the light guide plate 1 as light having a wide directivity. For this reason, the amount of light incident on the light guide plate 1 at an incident angle under the total reflection condition increases. As a result, it is possible to realize the pen 3 that has high use efficiency of the emitted light and high optical coupling efficiency with the light guide plate 1 of the pen input device 40. Furthermore, the position detection of the pen 3 is facilitated, and the detection accuracy of the touch position of the pen 3 is improved. Therefore, according to the configuration of FIG. 4, it is possible to realize the pen 3 with good signal quality due to light emission.

  The scattering unit 34 may be made of a transmissive material that transmits light having a wavelength in the visible region to the infrared region. For example, the light from the light source 31 may be scattered by including a light scatterer in the material. Is possible. Or it is possible to scatter the light from the light source 31 by performing the process which forms a rough surface, or the process which coats a light-scattering body containing material to a transmissive material.

  In particular, the scattering portion 34 is preferably composed of an elastic member 34 'as shown in FIGS. 3 (a) and 3 (b). The elastic member 34 ′ is deformed when the pen 3 touches the light guide plate 1. Therefore, when the pen 3 contacts the light guide plate 1, the area of the contact surface increases. Then, the light scattered by the elastic member 34 ′ as the scattering portion 34 is likely to enter the light guide plate 1 through the contact surface. As a result, the optical coupling efficiency with the light guide plate 1 of the pen input device 40 is further increased.

  The material constituting the elastic member 34 ′ may be a material that transmits light having a wavelength in the visible region to the infrared region. For example, a rubber material such as ethylene propylene rubber (EPDM) or butadiene rubber (BR) is used. Can be mentioned. Further, the light from the light source 31 can be scattered by including a light scatterer in the material of the elastic member 34 '. Alternatively, in order to scatter light from the light source 31, on at least one of the light incident surface 34′a (first surface) and the light emitting surface 34′b (second surface) of the elastic member 34 ′, A light scattering region A may be formed.

  For example, in the configuration of FIG. 3, the light scattering region A is formed on the light incident surface 34'a of the elastic member 34 '. The light scattering region A is composed of a rough surface (for example, a textured surface), and the light from the light source 31 is scattered.

  Thus, the use efficiency of light from the light source 31 can be increased by employing the elastic member 34 ′ made of a material that transmits light having a wavelength in the visible region to the infrared region as the scattering portion 34. Furthermore, the thickness of the scattering portion 34 can be increased, and the pen tip portion of the pen 3 is not damaged by wear. Further, by forming the light scattering region A on at least one of the light incident surface 34'a and the light emitting surface 34'b, the pen 3 having high light coupling efficiency with the light guide plate 1 can be realized.

(Modifications 1 and 2)
In the configuration of the pen 3 of the present embodiment, a modified example of the configuration shown in FIG. 4 will be described. 5A is a cross-sectional view schematically showing a schematic configuration of the pen 3 as the first modification, and FIG. 5B schematically shows a schematic configuration of the pen 3 as the second modification. FIG.

  As shown in FIG. 5A, in the pen 3 of the first modification, a reflection portion 36 that guides light from the light emitting element 31 a to the light emission position is provided on the side surface of the light source 31. As a result, of the light radiated from the light emitting element 31a, the light component having a wide radiation angle and reaching the side surface of the light source 31 is guided to the light emitting direction of the light source 31 (the direction toward the scattering unit 34) by the reflecting unit 36. It will be. Therefore, according to the pen 3 of the first modification, the loss of light can be eliminated and the amount of light guided to the scattering unit 34 can be increased, so that the light utilization efficiency can be further improved.

  Further, as shown in FIG. 5B, the pen 3 of Modification 2 is provided with a tilt angle holding member 37 that holds the tilt angle of the tip portion (light source 31) with respect to the light guide plate 1 constant. Yes. The tilt angle holding member 37 has a contact surface that contacts the light guide plate 1, and is held so that the optical axis of the light source 31 is tilted with respect to the light guide plate 1 when the contact surface contacts the light guide plate 1. It is comprised so that. Therefore, it can be said that the inclination angle holding member 37 is an inclination angle holding member that holds the inclination angle of the optical axis of the light source 31 with respect to the light guide plate 1 constant.

  As a result, the pen 3 touches the light guide plate 1 at a certain tilt angle without the tip portion touching the light guide plate 1 at various tilt angles. For this reason, the formation region of the scattering part 34 can be set so that the light emitted from the light source 31 inclined by the inclination angle held by the inclination angle holding member 37 is optically coupled to the light guide plate 1. Therefore, compared with the case where the pen 3 is touched to the light guide plate 1 at various inclination angles, the formation region of the scattering portion 34 can be narrowly limited. For example, in the configuration shown in FIG. 5B, when the scattering portion 34 is formed on the entire light exit surface of the light source 31, light that does not contribute to optical coupling from the pen 3 to the light guide plate 1 is scattered by the scattering portion 34. Since it is scattered, safety can be ensured. On the other hand, since the light that does not contribute to the optical coupling is scattered outside the pen 3 by the scattering portion 34, the light utilization efficiency is lowered. Therefore, in the configuration shown in FIG. 5B, if the scattering portion 34 is provided not in the entire light emitting surface of the light source 31 but in a partial region necessary for optical coupling with the light guide plate 1. Good.

(Modification 3)
In the configuration of the pen 3 of this embodiment, another modification of the configuration shown in FIG. 4 will be described. FIG. 6 is a cross-sectional view showing the configuration of the tip of the pen 3 as the third modification.

  As shown in FIG. 6, in the pen 3 of Modification 3, a sliding member 38 is provided on the contact surface (that is, the light emitting surface 34 ′ b) of the elastic member 34 ′ with the light guide plate 1. Thus, the sliding property between the light guide plate 1 and the pen 3 can be improved and a smooth writing feeling (touch feeling) can be realized, and the light coupling with the light guide plate 1 by the light scattering region A formed on the elastic member 34 ′. Efficiency can be improved.

  In addition, the sliding member 38 should just be a member which can improve the slidability of the light-guide plate 1 and the pen 3, For example, an ultra high molecular weight polyethylene film is mentioned. The ultra high molecular weight polyethylene film can be fixed to the light emitting surface 34 ′ b of the elastic member 34 ′ by heat welding.

  Instead of the sliding member 38, a light scattering region A having a fine uneven shape may be provided on the light emitting surface 34'b of the elastic member 34 '. The light scattering region A has a function of scattering light and improving the light coupling efficiency with the light guide plate 1. In addition to this function, when the elastic member 34 ′ is used by touching the light guide plate 1 of the pen input device 40, the contact area with the light guide plate 1 is reduced due to the fine uneven shape of the light scattering region A, and sliding. The frictional force when reduced is reduced. Therefore, the slidability between the light guide plate 1 and the pen 3 can be improved and a smooth writing feeling (touch feeling) can be realized.

  As described above, the pen 3 is provided with the light source 31 that emits infrared light. From the pen tip, the infrared light is coupled to the light guide plate 1 and propagates through the light guide plate 1. The infrared light propagating in the light guide plate 1 is scattered and radiated while being totally reflected. In this embodiment, the two-dimensional position coordinates of the contact position (touch position) of the pen 3 can be obtained with high accuracy based on the scattered light.

  Specifically, as shown in FIG. 1, the imaging units 10 and 20 respectively disposed at both ends of a certain side of the light guide plate 1 transmit infrared light propagating through the light guide plate 1 (hereinafter referred to as propagation). The light is described as light 4a and 4b), and the two-dimensional position coordinates of the contact are obtained from each image obtained from the image sensor 13. The light receiving surface of the image sensor 13 is disposed in parallel with the surface of the 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 contacts the touch surface (transparent light guide plate surface) of the pen input device, part of the infrared light emitted from the light pen enters the light guide plate 1 having a refractive index N. Of this incident light, the propagation angle θ _P in the light guide plate 1 is expressed by the formula:
sin (90 ° −θ _P )> 1 / N
2 is confined in the light guide plate 1 and repeatedly reflected on the front and back surfaces of the light guide plate 1 and travels in the light guide plate 1 as shown in FIG.

  Infrared light emitted from the pen 3 is scattered radially around the pen tip and propagates in the light guide plate 1, and some of the light beams 4 a and 4 b of the conical cut-out 1 a are formed. The light is also guided to the end face, and the reflected light of the end face is received by the imaging units 10 and 20. 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. 7A, the light emitted from the pen 3 propagates through the 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. 7A, 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. 7B 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 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 light from the light emitting unit comes into contact with the light guide plate 1 and the infrared light is coupled to the 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. 7 changes depending on the position of the contact point of the pen tip of the pen 3. 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 light guide plate 1. Is the same angle 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 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 distance L between the imaging 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 coordinate input system 50 is provided with a position coordinate detection unit (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.

  As described above, the coordinate 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 light guide plate 1.

  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 light guide plate 1, the touch surface of the light guide plate 1 is pen input. It becomes the uppermost surface of the device 40, and the image sensor does not protrude above the touch surface. Therefore, even when the pen input device 40 of the coordinate input system 50 of the present embodiment is applied to a table type terminal, the table surface can be made completely flat without the surroundings rising like a bank.

  Further, the coordinate input system 50 of the present embodiment is configured such that the light propagated inside the light guide plate is received by the image sensor, so that there is no possibility of erroneous recognition due to stray light including sunlight and accurate position detection. Therefore, it is possible to place the device outdoors or near a window.

  Further, the pen input device 40 of the coordinate input system 50 according to the present embodiment is configured so that the imaging units 10 and 20 that receive radiation light from the tip of the pen 3 are connected to the light guide plate 1 and light that does not propagate through the light guide plate 1 is transmitted. This structure is not coupled to the image sensors 13 and 23. Therefore, even if illumination light is applied from the normal direction of the touch surface of the light guide plate 1, since the light is not coupled to the 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.

  In the present embodiment, the light emitted from the tip of the pen 3 is scattered by the light scattering region A of the elastic member 34 ′ provided at the tip of the pen 3. Thereby, a sufficient amount of light can be coupled to the light guide plate 1. Therefore, accurate position detection can be realized.

  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 location in the edge part of the light-guide plate 1 is not limited to this. May be collected in one image sensor using a mirror and a shutter.

  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 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 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 a structure.

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

[Embodiment 2]
Another embodiment of the coordinate input system of the present invention will be described with reference to FIG. FIG. 8 is a perspective view showing the configuration of the coordinate input system of this embodiment. The difference between the present embodiment and the first embodiment described above lies in the configuration of both ends of a certain side of the light guide plate 1.

  Specifically, in the first embodiment, the mirror coating 6 is applied to the conical surface of the notch 1 a of the light guide plate 1. On the other hand, in the coordinate input system of the present embodiment, the notch 1a ′ of the light guide plate 1 of the pen input device 40 ′ (coordinate input device) is a cylinder having an angle perpendicular to or substantially perpendicular to the back surface of the light guide plate 1. A mirror coating is not applied to the cylindrical surface of the notch 1a ', and instead, mirror elements 14 and 24 are disposed adjacent to the notch 1a'. It differs in point.

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

  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 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 light guide plate 1 and emitted from the light guide plate 1. The light beam guided to the conical surfaces 14 a and 24 a and reflected by the conical surfaces 14 a and 24 a is guided in the direction of the back surface of the 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.

  The case where the size of the light guide plate 1 is as large as about 1 m square is assumed. In this case, as in the first embodiment, it is difficult in the process to perform mirror coating on the conical surfaces at the four corners of the light guide plate 1, and the cost is high. 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 light guide plate 1, and the work is easy. In addition, since many optical elements can be mirror-coated at the same time, the cost of the mirror elements 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 coordinate input system of the present invention will be described.

  In the first embodiment described above, light propagating through the light guide plate 1 is guided from both ends of one side of the light guide plate 1 to the lower side of the light guide plate 1 and imaged. On the other hand, in this embodiment, the same pen 3 (FIG. 1) and light guide plate 1 as in the first embodiment are used, and the infrared light emitted from the pen is not propagated in the transparent light guide plate. It is set as the aspect scattered along the surface of the said transparent light-guide plate. In this embodiment, an imaging unit similar to that in Embodiment 1 is provided at a position close to the surface of the transparent light guide plate, not below the transparent light guide plate, and receives light at the position. It has a configuration.

  The imaging units are provided at both ends of a certain side of the transparent light guide plate. When light scattered along the surface of the transparent light guide plate enters these image pickup units, a linear shape is obtained as in the first embodiment. An image is formed, and the proximity position coordinates of the pen 3 can be obtained based on the angle obtained in the same manner as in the first embodiment and the distance between the imaging elements.

  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 used in an arbitrary coordinate input system that inputs coordinates using a light-emitting pen. The coordinate input system can be applied to a personal computer, a television, a white board, a tablet terminal, and the like.

1 Light guide plate (light guide member)
1a, 1a ′ Notch (optical path conversion unit)
2 Liquid crystal display panel (display device)
3 Pen (operation member)
4a, 4b Luminous flux 6 Mirror coating 10, 20, 10 ', 20' Imaging unit (detection means)
11, 21 Lens 12, 22 Visible light cut filter 13, 23 Image sensor (light receiving unit)
14, 24 Mirror elements 14a, 24a Conical surfaces 14b, 24b Cylindrical surface 15 Linear image 16 Fan-shaped 17 Linear image 31 Light source 31a Light emitting element 31b Sealing resin portion 32 Drive device 33 Power supply device 34 Scattering portion 34 'Elasticity Member 34'a Light incident surface (first surface)
34'b Light exit surface (second surface)
35 Housing 36 Reflecting portion 37 Inclination angle holding member 38 Sliding member 40, 40 'Pen input device (coordinate input device)
50 Coordinate input system A Light scattering area

Claims (7)

An operation member that includes a light source and couples light from the light source to a light guide plate provided in the input device;
The light emitting position of the light source is provided with an elastic member that is deformed by contact with the light guide plate,
The operation member, wherein the elastic member is formed with a light scattering region for scattering light. The light source includes a light emitting element and a sealing resin portion that seals the light emitting element.
The operation member according to claim 1, wherein a reflection portion that guides light from the light emitting element to the light emission position is provided on a side surface of the light source.   The operation member according to claim 1, further comprising an inclination angle holding member that holds an inclination angle of the tip portion with respect to the light guide plate constant.   The operation member according to claim 1, wherein the elastic member contains a light scatterer. The light source includes a light emitting element and a sealing resin portion that seals the light emitting element, and is disposed at a tip portion of the operation member.
The operation member according to claim 1, wherein the light emitting element is an LED.   The operation member according to claim 1, wherein a sliding member is provided on a contact surface of the elastic member with the light guide plate. A light guide plate;
The operation member according to any one of claims 1 to 6,
At least two light receiving parts for receiving propagating light propagating in the light guide plate;
Detection for obtaining the coordinates of the contact position of the operation member with respect to the surface of the light guide member based on the output of the light receiving unit that detects propagation light based on the contact when the operation member is brought into contact with the surface of the light guide plate A coordinate input system comprising: means.

Images