JP3817069B2 - Coordinate input device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an input device that is attached to an electronic blackboard, a computer display, or the like, and more particularly to a coordinate input device that inputs information such as graphic drawing to a computer.
[0002]
[Prior art]
A coordinate input device capable of designating a predetermined position on a display screen by bringing a user's finger or a pen held by the user into contact with or approaching an electronic blackboard or a computer display which is a display device connected to a computer As one of these, a retroreflective member composed of a pair of light emitting devices that emit while rotating laser beam light, and a corner cube reflector that reflects the laser beam light to follow the same optical path again. JP-A-9-91094 discloses an optical coordinate input device that includes a pair of light receiving devices that receive the retroreflected light and detects a coordinate position. In this optical coordinate input device, a laser beam light is scanned in the coordinate input area, and a specific combination of laser beam lights is blocked by inserting a user's finger or the like into the coordinate input area. By detecting the emission angle of each blocked laser beam by each light receiving device, the coordinate position indicated by the user's finger or the like is calculated based on the emission angle.
[0003]
As a retroreflective member other than the corner cube reflector, for example, a tape-like retroreflective sheet such as “2000X (manufactured by 3M)” is known. Although this retroreflective sheet is inferior in retroreflective properties as compared with a corner cube reflector, it has an advantage of low cost and excellent flexibility in installation.
[0004]
[Problems to be solved by the invention]
However, an optical coordinate input device as described in JP-A-9-91094 is mounted on a display device having a display screen such as a liquid crystal display, a plasma display, or a flat CRT display, or an electronic blackboard. When this is attached to the writing surface, foreign matters such as fine particles, dust, and dust are likely to adhere to the coordinate input area due to static electricity. In addition, dust or the like that is increased in size by adsorbing dust or the like adhering to the screen surface and falling onto the retroreflective member from the screen surface is accumulated. When foreign matter such as dust accumulates on the retroreflective member in this way, the laser beam light may be blocked by the foreign matter such as dust. In such a case, the coordinate input device recognizes attached dust or the like as an instruction by a user's finger or the like, so that erroneous information is transmitted as electronic data, causing a problem in reliability of position coordinate detection. It will be.
[0005]
On the other hand, when a retroreflective sheet is used as the retroreflective member, the retroreflective sheet does not have a complete retroreflective property like a corner cube reflector. There is a problem that scattered light or the like is generated. This scattered light can be generated not only by the laser beam light from the light emitting device but also by an external light beam irradiated from, for example, external illumination. As described above, the scattered light generated by the incidence of the external light beam on the retroreflective sheet causes light reception noise in the light receiving device or causes the display quality of the display screen of the display device to deteriorate. That is, in a coordinate input device using a retroreflective sheet, abnormal information is transmitted as electronic data due to the occurrence of light reception noise, which causes a problem in reliability of position coordinate detection.
[0006]
An object of the present invention is to obtain a coordinate input device capable of improving the reliability of position coordinate detection.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, each irradiation light emitted from a plurality of light receiving and emitting devices having a light source and a light receiving element is crossed, and each irradiation light is retroreflected to each light receiving and emitting device by a retroreflective member. In the coordinate input device for detecting the position coordinates of the pointing means inserted into the coordinate input area which is the irradiation light scanning area formed by the above, the coordinate input area is arranged in a substantially vertical direction, and is from the lower end of the coordinate input area A foreign matter removing member having a tapered shape having an inclined surface inclined with respect to the reflective surface of the retroreflective member provided below and having at least a transparent passage position of the irradiation light is provided on the retroreflective member. .
[0008]
Therefore, in the coordinate input apparatus for detecting the position coordinates of a plurality of light receiving and emitting device inserted indicating means to the coordinate input region is irradiation light scanning region of the irradiation light emitted from the light source, below the lower end of the coordinate input region A foreign substance exclusion member having a tapered shape having an inclined surface inclined with respect to the reflection surface of the provided retroreflective member and having at least a transparent passage position of irradiation light is provided below the lower end of the coordinate input area . By being provided on the retroreflective member, the foreign matter that has reached the foreign matter removing member is removed along the inclined surface of the foreign matter removing member. On the other hand, since the irradiation light passing position is transparent, the irradiation light is transmitted through the foreign matter exclusion member and is retroreflected by the retroreflection member. This prevents foreign matter from accumulating on the retroreflective member provided below the lower end of the coordinate input area , and prevents erroneous irradiation light from being blocked due to the presence of the foreign matter.
[0009]
According to a second aspect of the present invention, in the coordinate input device according to the first aspect, the reflective surface of the retroreflective member provided below the lower end of the coordinate input area is inclined with respect to the coordinate input area. The incident angle of the irradiation light that has passed through the foreign matter exclusion member to the reflection surface of the retroreflective member is substantially vertical.
[0010]
Accordingly, the reflective surface of the retroreflective member provided below the lower end of the coordinate input area is inclined with respect to the coordinate input area, so that the reflective surface of the retroreflective member of the irradiation light transmitted through the foreign substance exclusion member Since the incident angle to is substantially vertical, attenuation of received light power in the light receiving element depending on the incident angle is kept to a minimum.
[0013]
The invention according to claim 3 crosses each irradiation light emitted from a plurality of light emitting / receiving devices having a light source and a light receiving element, and retroreflects each irradiation light to each light receiving / emitting device by a retroreflective member. In the coordinate input device for detecting the position coordinates of the pointing means inserted in the coordinate input area which is the irradiation light scanning area formed by the above, the coordinate input area is arranged in a substantially vertical direction and charged to a predetermined polarity A conductive thin film is provided at the non-passing position of the irradiation light on the retroreflective member provided below the lower end of the coordinate input area.
[0014]
Therefore, for example, a conductive thin film charged with a polarity opposite to that of a foreign object is provided at a position where the irradiation light does not pass on a retroreflective member provided below the lower end of the coordinate input area , thereby allowing retroreflection. The foreign matter that has reached the member is electrically adsorbed by the conductive thin film on the retroreflective member, and is removed at a position that does not affect the irradiation light . On the other hand, since the conductive thin film is not provided at the irradiation light passage position, the irradiation light is retroreflected by the retroreflection member. This prevents foreign matter from accumulating on the retroreflective member provided below the lower end of the coordinate input area , and prevents erroneous irradiation light from being blocked due to the presence of the foreign matter.
[0015]
According to a fourth aspect of the present invention, in the coordinate input device according to the third aspect of the present invention, the light shielding device is provided at a substantially right angle with respect to the reflective surface of the retroreflective member and blocks external light directly incident on the retroreflective member. A plate is further provided.
[0016]
Therefore, a light shielding plate that blocks external light rays that are directly incident on the retroreflective member is provided substantially at right angles to the reflective surface of the retroreflective member. Thereby, since the external light beam directly incident on the retroreflective member is blocked by the light shielding plate, generation of scattered light by the retroreflective member is prevented.
[0017]
According to a fifth aspect of the present invention, in the coordinate input device according to any one of the first to fourth aspects, the coordinate input area is provided above an upper end of the coordinate input area , and is extended from the upper end of the coordinate input area along the coordinate input area. A blower that blows downward toward the lower end is further provided.
[0018]
Accordingly, a blower that blows downward along the coordinate input area is provided above the upper end of the coordinate input area. As a result, the foreign matter in the coordinate input area is excluded from the upper part toward the lower end of the coordinate input area along the coordinate input area by the air blown from above, and is then moved downward to the retroreflective member.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIG. The coordinate input device according to the present embodiment is applied to a coordinate input device that is used by being mounted on a writing surface of an electronic blackboard.
[0020]
Here, FIG. 1A is a front view schematically showing the configuration of the coordinate input device 1, FIG. 1B is a side view thereof, and FIG. 1C is a cross-sectional view mainly showing the vicinity of the blower device 12. The coordinate input device 1 mounted on the writing surface E of the electronic blackboard has a coordinate input area 2 which is a rectangular space and has substantially the same area as the writing surface E of the electronic blackboard. At both upper ends of the coordinate input area 2, there are provided light emitting / receiving devices 3 (left light emitting / receiving device 3L, right light emitting / receiving device 3R) for emitting and receiving light beams. The light emitting / receiving device 3 (left light emitting / receiving device 3L, right light emitting / receiving device 3R) includes a laser diode (hereinafter referred to as LD) 4 that is a light source that emits laser light. The laser light emitted from the LD 4 passes through the half mirror 5 and is then sequentially reflected radially by a polygon mirror 6 that is rotationally driven by a motor (not shown), for example, L1, L2,..., Ln (R1 , R2,..., Rn) are repeatedly irradiated in parallel along the surface of the coordinate input area 2 (writing surface E of the electronic blackboard) as a light beam (probe light).
[0021]
In addition, a retroreflective sheet 7 that is a retroreflective member is provided inside the coordinate input device 1 and in a peripheral portion excluding the upper portion of the coordinate input region 2. The retroreflective sheet 7 has a characteristic of reflecting incident light toward a predetermined position regardless of the incident angle. Furthermore, on the retroreflective sheet 7 provided in the lower part of the coordinate input device 1, a foreign matter removing member 11 having an inclined surface 11a that is a tapered surface is provided. The foreign matter removing member 11 is formed of a transparent material having a refractive index of about 1.5 (for example, optical glass or PMMA which is a kind of methacrylic resin).
[0022]
Here, FIG. 2 is a cross-sectional view schematically showing a part of the coordinate input device 1. As shown in FIG. 2, with respect to the retroreflective sheet 7 provided at the lower part of the coordinate input device 1, the reflection surface 7a is set at an angle θ with respect to the vertical direction of the coordinate input area 2 (writing surface E of the electronic blackboard). It is provided only with an inclination. Here, the angle θ is an angle at which the light beam incident on and refracted by the foreign substance exclusion member 11 is incident substantially perpendicularly to the reflection surface 7 a of the retroreflection sheet 7. In this way, by making the light beam incident substantially perpendicular to the reflecting surface 7a of the retroreflective sheet 7, the attenuation of the optical power of the light received by the light receiving element 9 described later is kept to a minimum. Thus, the reliability of the position coordinate detection of the coordinate input device 1 can be improved.
[0023]
Then, for example, the probe light L1 emitted from the left side light receiving and emitting device 3L is transmitted through the foreign substance exclusion member 11 and reflected on the reflection surface 7a of the retroreflective sheet 7, and the left side as retroreflected light L1 ′ that follows the same optical path again. It progresses toward the light emitting / receiving device 3L. The retroreflected light reflected from the retroreflective sheet 7 and returned to the polygon mirror 6 is folded by the half mirror 5, passes through the condenser lens 8, and is collected by the light receiving element 9. The light receiving element 9 is composed of, for example, a PIN photodiode, and converts the optical power of the received retroreflected light into an electric signal (output voltage value).
[0024]
The light receiving element 9 is connected to a calculation unit 10 controlled by a microcomputer (not shown) equipped with a CPU and the like. The calculation unit 10 calculates position coordinates (x, y) of the light shielding object A that is an instruction unit based on an electric signal from the light receiving element 9. In addition, the calculation method of the position coordinate (x, y) of the light shielding object A by the calculation unit 10 obtains the angle of the probe light blocked by the light shielding object A by the number of pulses of a motor that rotates the polygon mirror 6, for example. This is based on a known method such as calculating the position coordinates (x, y) of the light shielding object A based on the above.
[0025]
In addition, a blower 12 is provided between the light receiving / emitting device 3 (the left light emitting / receiving device 3L and the right light receiving / emitting device 3R) of the coordinate input device 1 and the coordinate input region 2. Next, the air blower 12 will be described. As shown in FIG. 1 (c), the air blower 12 is provided with intake ports 13 that are opened on both side surfaces of the coordinate input device 1, and an intake fan 14 is provided at the back of the intake port 13. Are provided. An air blowing path 15 is formed between the fans 14. The air blowing path 15 is provided with a blower unit 16 having a plurality of blower holes 16a at the bottom. The air blower 16 has a structure that can uniformly send the air flow a along the surface of the writing surface E of the electronic blackboard. The air blower 16 has a height that does not interfere with the light beam from the polygon mirror 6.
[0026]
Further, the microcomputer described above controls the light emission timing of the LD 4 and the drive timing of the motor, whereby the laser beam is scanned and the coordinate input area 2 is formed.
[0027]
In such a configuration, for example, as shown in FIG. 1A, an appropriate position (x, y) on the writing surface E of the electronic blackboard is a light shielding object via the coordinate input area 2 of the coordinate input device 1. When writing is performed with the pen A, the probe lights Ln and Rn irradiated from the light emitting / receiving device 3 (left light emitting / receiving device 3L, right light emitting / receiving device 3R) are blocked. Accordingly, since the probe lights Ln and Rn blocked by the pen A do not reach the retroreflective sheet 7, the retroreflected light of the probe lights Ln and Rn is received / received by the light emitting / receiving device 3 (left light receiving / emitting device 3L, right receiving / receiving device). Light is not received by each light receiving element 9 of the light emitting device 3R). That is, in this case, no electrical signal is output from the light receiving element 9. Accordingly, the calculation unit 10 calculates the angles of the probe lights Ln and Rn for which no electrical signal has been output based on the number of pulses of the motor when these probe lights are emitted, and the pen 10 based on these angles. The position coordinates (x, y) written by A are calculated. The position coordinates (x, y) calculated in this way are processed as electronic data for writing on the writing surface E by the pen A.
[0028]
On the other hand, when the coordinate input device 1 is activated, driving of each fan 14 of the blower device 12 is started. By driving the fan 14, air is drawn from each intake port 13 and drawn into the air blowing path 15. The air drawn into the air blowing path 15 is sent to the blowing section 16 and sent out as a plurality of air flows a along the surface of the writing surface E of the electronic blackboard from the plurality of blowing holes 16a. The air flow a sent out in this manner blows away dust or the like that is a foreign matter adhering to the writing surface E of the electronic blackboard and drops it downward. In addition, the fallen dust or the like is removed from the coordinate input device 1 along the inclined surface 11a of the foreign material exclusion member 11 by the air flow a.
[0029]
Here, by providing the air blower 12 and sending the air flow a into the coordinate input area 2 of the coordinate input apparatus 1, adhesion of dust or the like to the coordinate input area 2 is prevented, and the coordinate input apparatus 1. The foreign matter removal member 11 is provided on the retroreflective sheet 7 provided in the lower part of the coordinate input area 2 to remove the fallen dust from the coordinate input device 1 so that the dust on the retroreflective sheet 7 is removed. Is prevented from accumulating. Accordingly, erroneous electronic data processing due to the probe light being blocked by dust or the like is prevented, so that the reliability of position coordinate detection of the coordinate input device 1 can be improved.
[0030]
Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those in FIGS. 1 and 2 described in the first embodiment of the present invention are denoted by the same reference numerals, and the description thereof is also omitted.
[0031]
3A is a front view schematically showing the configuration of the coordinate input device 20, and FIG. 3B is a side view thereof. The coordinate input device 20 according to the present embodiment and the coordinate input device 1 according to the first embodiment of the present invention are provided with a horizontal air blower 21 instead of the foreign matter removing member 11 that functions as a foreign matter removing means. Is different.
[0032]
The horizontal blower 21 is provided at any one of the longitudinal ends of the retroreflective sheet 7 provided below the coordinate input area 2 of the coordinate input device 20. The horizontal blower 21 is provided with an intake port 22, and an intake fan 23 is provided in the vicinity of the intake port 22. In addition, the horizontal air blower 21 has a structure in which the air inhaled by the fan 23 can be sent along the surface of the retroreflective sheet 7 from the horizontal direction.
[0033]
In such a configuration, when the coordinate input device 20 is activated, the driving of each fan 14 of the blower 12 is started, and the driving of the fan 23 of the lateral blower 21 is started. By driving each fan 14 of the blower device 12, a plurality of airflows a along the surface of the writing surface E of the electronic blackboard are sent out from the plurality of blower holes 16 a of the blower unit 16. On the other hand, the air flow b is sent out along the surface of the retroreflective sheet 7 by driving the fan 23 of the horizontal blower 21. The air flow a sent out in this manner blows away dust and the like adhering to the writing surface E of the electronic blackboard and drops it downward. The fallen dust or the like is blown off along the surface of the retroreflective sheet 7 by the air flow b from the lateral direction, and is excluded from the coordinate input device 20.
[0034]
Here, by providing the air blower 12 and sending the air flow a into the coordinate input area 2 of the coordinate input device 20, dust and the like are prevented from adhering to the coordinate input area 2, and the coordinate input apparatus 20. The horizontal air blower 21 is provided at one of the longitudinal end portions of the retroreflective sheet 7 provided at the lower part of the coordinate input area 2 to coordinate the dust etc. dropped by sending the air flow b from the lateral direction. By removing from the input device 20, accumulation of dust etc. on the retroreflective sheet 7 is prevented. Accordingly, erroneous electronic data processing due to the probe light being blocked by dust or the like is prevented, so that the reliability of position coordinate detection of the coordinate input device 20 can be improved.
[0035]
Next, a third embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is used about the same part as the part of FIG. 1 thru | or FIG. 3 demonstrated in 1st or 2nd embodiment of this invention, and description is also abbreviate | omitted.
[0036]
4A is a front view schematically showing the configuration of the coordinate input device 30, and FIG. 4B is a side view thereof. The coordinate input device 30 according to the present embodiment and the coordinate input device 1 according to the first embodiment of the present invention are provided with a conductive thin film 31 in place of the foreign substance exclusion member 11 that functions as a foreign substance exclusion means. And it differs in the point provided with the light-shielding plate 32 for every retroreflection sheet 7. FIG.
[0037]
The conductive thin film 31 is provided in a portion other than the probe light passage position of the retroreflective sheet 7 provided in the lower part of the coordinate input area 2 of the coordinate input device 30. The conductive thin film 31 is made of a conductive thin film material such as indium oxide, and has a polarity opposite to the polarity of the charged potential of dust or the like. Here, dust or the like is charged to the negative electrode, and the conductive thin film 31 is charged to the positive electrode.
[0038]
Further, the light shielding plate 32 is made of an opaque material, and is provided at a side edge of the retroreflective sheet 7 so as to be perpendicular to the reflective surface 7a. At least prevent. The light shielding plate 32 is provided at a position that does not interfere with the writing surface E of the electronic blackboard.
[0039]
In such a configuration, when the coordinate input device 30 is activated, driving of each fan 14 of the blower 12 is started. Then, by driving each fan 14 of the blower device 12, a plurality of airflows “a” along the surface of the writing surface E of the electronic blackboard is sent out from the plurality of blower holes 16 a of the blower unit 16. The air flow a sent out in this manner blows off dust and the like adhering to the writing surface E of the electronic blackboard and drops it onto the retroreflective sheet 7 provided below the coordinate input area 2. Further, dust or the like dropped on the retroreflective sheet 7 provided in the lower part of the coordinate input area 2 is electrically adsorbed by the conductive thin film 31 on the retroreflective sheet 7. In this case, since the conductive thin film 31 is not provided at the probe light passage position, dust or the like is excluded at a position that does not affect the probe light.
[0040]
On the other hand, let us consider external light rays emitted from external illumination. Here, FIG. 5 is a cross-sectional view schematically showing a part of the coordinate input device 30. As shown in FIG. 5, even when the external light beam c is emitted from the external illumination, the provision of the light shielding plate 32 prevents the external light beam c from directly entering the retroreflective sheet 7. The generation of scattered light is prevented.
[0041]
Here, by providing the air blower 12 and sending the air flow a into the coordinate input area 2 of the coordinate input device 30, adhesion of dust and the like to the coordinate input area 2 is prevented, and the coordinate input apparatus 30 is provided. The retroreflective sheet 7 is provided with a conductive thin film 31 at a portion other than the probe light passing position of the retroreflective sheet 7 provided below the coordinate input area 2 to electrically adsorb the fallen dust and the like. The accumulation of dust or the like at the probe light passage position on 7 is prevented. Accordingly, erroneous electronic data processing due to the probe light being blocked by dust or the like is prevented, so that the reliability of position coordinate detection of the coordinate input device 30 can be improved.
[0042]
In addition, by providing the light shielding plate 32 to prevent direct incidence of the external light beam c on the retroreflective sheet 7 and the generation of scattered light, the occurrence of light reception noise in the light receiving element 9 is prevented. Thereby, since abnormal electronic data processing is prevented, the reliability of the coordinate input device 30 can be further improved.
[0043]
In each embodiment, an openable / closable shutter mechanism may be further provided on the retroreflective sheet 7, and may be opened only when the apparatus is used. Thereby, adhesion and accumulation of dust or the like on the retroreflective sheet 7 when the apparatus is not used are prevented.
[0044]
Further, in each embodiment, when a shielding object is detected at the same time as the activation of the coordinate input device, it is assumed that dust or the like is present, and the presence of dust or the like is notified by voice or light as notification means. You may do it.
[0045]
【The invention's effect】
According to the first aspect of the invention, the coordinates of the coordinate input apparatus for detecting the position coordinates of a plurality of light receiving and emitting device inserted indicating means to the coordinate input region is irradiation light scanning region of the irradiation light emitted from the light source A foreign object having a taper shape having an inclined surface inclined with respect to the reflective surface of the retroreflective member on the retroreflective member provided below the lower end of the input region , and at least the irradiation light passing position is transparent An exclusion member is provided, and foreign matter that has reached the foreign matter exclusion member is eliminated along the inclined surface of the foreign matter exclusion member to prevent foreign matter from accumulating on the retroreflective member provided below the lower end of the coordinate input area. as well as, by retroreflection in retroreflection member irradiation light is transmitted through the foreign object removing member, to prevent the interruption of the irradiation light erroneous due to the presence of foreign material, it is possible to prevent the processing of the erroneous electronic data Since wear, it is possible to improve the reliability of the position coordinate detection of the coordinate input device.
[0046]
According to a second aspect of the present invention, in the coordinate input device according to the first aspect, the reflective surface of the retroreflective member provided below the lower end of the coordinate input area is inclined with respect to the coordinate input area. As a result, the incident angle of the irradiation light that has passed through the foreign matter exclusion member to the reflection surface of the retroreflective member is set to be substantially vertical, so that the attenuation of the received light power in the light receiving element depending on the incident angle can be kept to a minimum.
[0048]
According to invention of Claim 3, the coordinate of the coordinate input device which detects the position coordinate of the instruction | indication means inserted in the coordinate input area | region which is the irradiation light scanning area | region of the irradiation light radiate | emitted from the light source of several light emitting / receiving apparatus A conductive thin film charged to a predetermined polarity is provided at a non-passing position of irradiation light on the retroreflective member provided below the lower end of the input area , and the foreign matter that has reached the retroreflective member is treated as the polarity of the foreign matter. To the retroreflective member provided below the lower end of the coordinate input area by being electrically adsorbed by a conductive thin film charged to the opposite polarity to that of the electrode and excluding the position where it does not affect the irradiated light . In addition to preventing the accumulation of foreign materials, the irradiation light is retroreflected on the retroreflecting member without providing a conductive thin film at the irradiation light passage position, thereby preventing erroneous irradiation light from being blocked due to the presence of foreign materials, Incorrect electronic data It is possible to prevent the processing, it is possible to improve the reliability of the position coordinate detection of the coordinate input device.
[0049]
According to a fourth aspect of the present invention, in the coordinate input device according to the third aspect, the light-shielding plate that blocks the external light beam that is directly incident on the retroreflective member is provided substantially at right angles to the reflective surface of the retroreflective member. As a result, the external light beam directly incident on the retroreflective member is blocked by the light shielding plate and the scattered light is prevented from being generated by the retroreflective member, so that it is possible to prevent the occurrence of light reception noise in the light receiving element, Processing of electronic data can be prevented.
[0050]
According to invention of Claim 5, in the coordinate input device as described in any one of Claim 1 thru | or 4 , the air blower which ventilates below toward the lower end toward the lower end of the coordinate input area along a coordinate input area. By providing the coordinate input area above the upper end of the coordinate input area, foreign matter in the coordinate input area is excluded from the upper part to the lower retroreflective member along the coordinate input area by blowing from above. It can prevent hypertrophy.
[Brief description of the drawings]
FIG. 1 shows a coordinate input device according to a first embodiment of the present invention, in which (a) is a front view schematically showing the configuration of the coordinate input device, (b) is a side view thereof, and (c) is an air blower. FIG. 2 is a cross-sectional view mainly showing the vicinity of the apparatus.
FIG. 2 is a cross-sectional view schematically showing a part of the coordinate input device.
3A and 3B show a coordinate input device according to a second embodiment of the present invention, in which FIG. 3A is a front view schematically showing a configuration of the coordinate input device, and FIG. 3B is a side view thereof.
4A and 4B show a coordinate input device according to a third embodiment of the present invention, in which FIG. 4A is a front view schematically showing a configuration of the coordinate input device, and FIG. 4B is a side view thereof.
FIG. 5 is a cross-sectional view schematically showing a part of the coordinate input device.
[Explanation of symbols]
2 Coordinate input area 3 Light receiving / emitting device 4 Light source 7 Retroreflective member 7a Reflective surface 9 of retroreflective member Light receiving element 11 Foreign matter removing member 11a Inclined surface 12 of foreign matter removing member Blower 21 Horizontal blower 31 Conductive thin film 32 Light shielding Plate A Indicating means Ln, Rn Light beam

Claims (5)

Irradiation light scanning formed by intersecting each irradiation light emitted from a plurality of light receiving and emitting devices having a light source and a light receiving element and retroreflecting each irradiation light to each light receiving and emitting device by a retroreflective member In the coordinate input device for detecting the position coordinates of the pointing means inserted in the coordinate input area which is an area,
The coordinate input area is arranged in a substantially vertical direction,
A foreign substance exclusion member having a tapered shape having an inclined surface inclined with respect to the reflection surface of the retroreflective member provided below the lower end of the coordinate input area and at least the position where the irradiation light passes is transparent. A coordinate input device provided on a retroreflective member. The reflective surface of the retroreflective member provided below the lower end of the coordinate input region is provided to be inclined with respect to the coordinate input region, and the retroreflective member of the irradiation light transmitted through the foreign matter exclusion member The coordinate input device according to claim 1, wherein an incident angle to the reflecting surface is substantially vertical. Irradiation light scanning formed by intersecting each irradiation light emitted from a plurality of light receiving and emitting devices having a light source and a light receiving element and retroreflecting each irradiation light to each light receiving and emitting device by a retroreflective member In the coordinate input device for detecting the position coordinates of the pointing means inserted in the coordinate input area which is an area,
The coordinate input area is arranged in a substantially vertical direction,
A coordinate input device, wherein a conductive thin film charged to a predetermined polarity is provided at a position where the irradiation light does not pass on the retroreflective member provided below a lower end of the coordinate input region. The coordinate input device according to claim 3 , further comprising a light shielding plate that is provided at a substantially right angle with respect to the reflection surface of the retroreflective member and blocks external light rays that are directly incident on the retroreflective member. The provided upward from the upper end of the coordinate input region, the blower further comprises claims 1 to 4 of any one described for blowing air from the upper end of the coordinate input region along the coordinate input region downwardly towards the lower end Coordinate input device.

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