JP2000132339A - Coordinate input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a coordinate position in the case of simultaneously instructing two points at a low cost. SOLUTION: Conserning this device 1, a light beam scanned from a first light emitting device 3a provided while facing a reflecting member 10 is reflected by the reflecting member 10. Namely, three scanned beams, which are emitted from two light emitting devices, composed of light beam scanned from a second light emitting device 3b, light beam scanned from the first light emitting device 3a and reflected light beam which is scanned from the first light emitting device 3a and reflected on the reflecting member 10 are existent inside a coordinate input area 2. Thus, when two inserts A and B are inserted to the intersection of these three scanned beams and respective light beams are shielded, even without providing three light emitting devices, based on light receiving signals outputted by respective photodetectors 9, the coordinate of position where these inserts A and B are inserted is detected by a coordinate detecting means so that the coordinate position in the case of simultaneously instructing two points can be detected at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input device attached to an electronic blackboard, a computer display, or the like, and more particularly to a coordinate input device for inputting information such as drawing of a graphic to a computer.

[0002]

2. Description of the Related Art In recent years, a user's finger or a pen held by a user contacts or approaches a computer display or the like, which is a display device connected to an electronic blackboard or a computer, so that a predetermined position on the display screen is obtained. A coordinate input device that can be designated has been considered. As an example, there is a coordinate input device described in Japanese Patent Application Laid-Open No. 9-91094. Here, FIG. 16 is a front view schematically showing a conventional coordinate input device 100. As shown in FIG. 16, the coordinate input device 100 includes a light emitting device that emits a laser beam a toward a predetermined position while rotating the laser beam a, and a light receiving device that receives a retroreflected light b of the laser beam a. A pair of light scanners 101 (101R, 101L) provided at a distance Z apart from each other, and a retroreflective member 102 that reflects the laser beam light a and turns it into retroreflected light b that follows the same optical path again. The portion scanned by the light a is the coordinate input area 103. The light emitting device of the light scanner 101 is driven by a driving device (not shown), and the driving of the driving device is pulse-controlled.

In such an optical coordinate input device 100, a specific combination of laser beam light a is inserted by inserting a user's finger A or the like into the coordinate input area 103.
Since 1 and a2 are cut off, no retroreflected light is generated. When the retroreflected light does not occur, the light receiving signal of the light receiving device of the light scanner 101 becomes “L”.
(LOW) level signal in a detection unit (not shown). Further, in the detection unit, the emission angle of each laser beam light a1, a2 of the “L” level signal is based on the number of pulses that have been driven and controlled by the driving device until the laser beam light a1, a2 is emitted. Detected. Then, the coordinate position (x, y) specified by the user's finger A is calculated by the arithmetic circuit 104 based on the emission angle of the laser beam light a1, the emission angle of the laser beam light a2, and the distance Z. It will be calculated by the principle. The coordinate position (x, y) calculated in this way is output to a computer or the like via the interface circuit 105.

Therefore, when the coordinate input device described in Japanese Patent Application Laid-Open No. 9-91094 is applied to an electronic blackboard or the like that requires a large coordinate input area, the installation position of each light scanner must be changed. Since it is only necessary to extend the retroreflective member, it is easy to maintain the installation accuracy and the like structurally.

[0005]

Here, a case in which the user's fingers A and B are simultaneously inserted into the coordinate input area 103 of the coordinate input device 100 and two points are simultaneously specified will be described with reference to FIG. . FIG. 18 is a time chart showing a relationship between a light receiving signal and a pulse signal in each of the light scanners 101R and 101L when two points are designated at the same time. In FIG. 17 and FIG.
It is assumed that laser beam light scanning from the light scanners 101R and 101L is divided into eight directions based on pulse signals, respectively.
It is assumed that the laser beam is located at the intersection of the laser beams scanned from 1L. As described above, when the laser beam is simultaneously cut off at each of the cutoff points A and B, as shown in FIG. 18, the light scanner 101R detects "L" level light-receiving signals at positions 3 and 6. And light scanner 1
From “01L”, light receiving signals of “L” level are detected at positions 3 and 5.

However, when the light scanners 101R and 101L of the coordinate input device 100 detect the light receiving signals of the "L" level corresponding to two points, the points A 'and A' B ′ may be erroneously recognized. That is, the combination of the pulse signals based on the “L” level light receiving signal is as follows: A (101L, 101R) = (5, 3) A ′ (101L, 101R) = (3, 3) B (101L, 101R) = ( (3, 6) B ′ (101L, 101R) = (5, 6), so that it is not possible to determine one cutoff point.

Therefore, in the coordinate input device 100 described in Japanese Patent Application Laid-Open No. 9-91094, it is impossible to detect the coordinate positions of two points when two points are specified at the same time.

In order to detect the coordinate positions of two points when they are specified simultaneously, it is necessary to provide another light scanner and have three scanning lights, but the number of parts increases. At the same time, there is a problem that the device configuration becomes complicated, resulting in an expensive configuration.

An object of the present invention is to provide a coordinate input device capable of detecting a coordinate position when two points are simultaneously designated at a low cost.

An object of the present invention is to provide a coordinate input device capable of reducing the load of arithmetic processing.

An object of the present invention is to provide a coordinate input device capable of preventing occurrence of light receiving noise in a light receiving element.

An object of the present invention is to provide a coordinate input device having a long device life.

[0013]

According to the first aspect of the present invention,
A rectangular frame-shaped housing, a reflecting member disposed on one side of the inner periphery of the housing, and a light source provided at an end of one side of the inner periphery of the housing facing the reflecting member, and having a light source. A first light emitting device that radially scans each light beam emitted from the light source toward the inside of the housing; and a light source provided at an end of one side of the inner circumference of the housing where the reflection member is provided. A second light emitting device that radially scans each light beam emitted from the light source toward the inside of the housing, and is formed by the intersection of each light beam scanned from these light emitting devices and indicates coordinates. A coordinate input area for receiving insertion of an insert to be inserted, and three peripheral edges of the coordinate input area except for one side on which the reflection member is disposed, which are arranged on three sides of the housing inner periphery, and are scanned from each light emitting device. A retroreflective member for retroreflecting a light beam to be emitted, A light receiving element for receiving a light beam retroreflected by the retroreflective member, converting the optical power of the received light beam into an electric signal, and outputting the electric signal as a light receiving signal; The coordinates of the light beam scanned from the device, the light beam scanned from the first light emitting device, and the reflected light beam reflected by the reflecting member from the light beam scanned from the first light emitting device. When one or two of the inserts are inserted at the intersections in the input area to block each light beam, coordinate detection for detecting the position coordinates of the inserts based on the light receiving signals output by the light receiving elements. Means.

Therefore, the light beam scanned from the first light emitting device provided opposite the reflecting member is reflected by the reflecting member. That is, in the coordinate input area, the light beam scanned from the second light emitting device, the light beam scanned from the first light emitting device, and the light beam scanned from the first light emitting device are reflected by the reflecting member. There are three scanning lights emitted from the two light emitting devices composed of the reflected light beam reflected. This allows 2
When one insert is inserted at the intersection of these three scanning lights and each light beam is cut off, the position coordinates at which those inserts are inserted are detected based on the light receiving signal output by each light receiving element. Become.

According to a second aspect of the present invention, in the coordinate input device according to the first aspect, the light beam scanned from the first light emitting device and the light beam scanned from the second light emitting device are different from each other. The scanning height positions in the coordinate input area are different from each other.

Therefore, by changing the scanning height position in the coordinate input area of the light beam scanned from each light emitting device, the detection of the interruption point based on the light receiving signal of the light beam scanned from the first light emitting device. And the detection of the interruption point based on the light receiving signal of the light beam scanned from the second light emitting device is processed with a time difference.

The third aspect of the present invention is the first or second aspect.
The coordinate input device according to the above, further comprising a light shielding plate provided at a side edge portion of the reflection member to block an external light beam directly incident on the reflection member.

Accordingly, since the light-shielding plate is provided at the side edge of the reflecting member, an external light beam directly incident on the reflecting member is blocked, so that the generation of scattered light by the reflecting member is prevented.

The invention described in claim 4 is the first to third aspects of the present invention.
In the coordinate input device according to any one of the above, during standby for insertion of the insert into the coordinate input area, only the second light emitting device is driven without driving the first light emitting device, the second The apparatus further includes a stepped light scanning unit that drives the first light emitting device immediately after the light beam scanned from the light emitting device is blocked by the insert.

Therefore, during standby for insertion of the insert into the coordinate input area, only the second light emitting device is driven without driving the first light emitting device, and the light beam scanned from the second light emitting device is inserted. The first light emitting device is driven immediately after being blocked by the object, so that the driving of the first light emitting device is started immediately before the insertion of the insert, so that the light beam scanned from the first light emitting device is also provided. It will be blocked by the insert.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. The coordinate input device of the present embodiment is connected to a personal computer (hereinafter, referred to as a personal computer), and is applied to a coordinate input device mounted on a surface of a computer display.

FIG. 1 is a front view schematically showing the configuration of the coordinate input device 1, and FIG. 2 is a side view thereof. Coordinate input device 1 mounted on the surface of computer display D
Has a coordinate input area 2 which is a rectangular space inside a rectangular frame-shaped housing 1a. Light-receiving / light-emitting devices 3 (upper light-receiving / light-emitting device 3a, lower light-receiving / light-emitting device 3b) that respectively perform light-emitting scanning and light-receiving of light beams are provided in housings 1a located on the upper right side and lower left side of the coordinate input area 2. Are provided on a diagonal line. Here, the upper light emitting / receiving device 3a functions as a first light emitting device, and the lower light receiving / emitting device 3b functions as a second light emitting device. Each of the light receiving and emitting devices 3 (upper light receiving and emitting device 3a, lower light receiving and emitting device 3b) has the same configuration, and includes a laser diode (hereinafter, referred to as an LD) 4, which is a light source for emitting laser light, and a half. It includes a mirror 5, a polygon mirror 6, a condenser lens 8, a light receiving element 9, and the like. The laser light emitted from the LD 4 is transmitted to the half mirror 5
After passing through, the motors M1 and M2 described later (see FIG. 3)
Are sequentially reflected by the polygon mirror 6 driven to rotate, and repeatedly scanned radially as a parallel light beam (probe light) along the surface of the coordinate input area 2 (computer display D).

As shown in FIG. 2, the polygon mirror 6 of the upper light emitting / receiving device 3a has a computer display D.
The probe light scans at a position at a height h1 from the surface of the computer display D. The polygon mirror 6 of the lower light emitting / receiving device 3b scans the probe light at a position at a height h2 from the surface of the computer display D. It has been. Note that h
The relationship between 1 and h2 is h1 <h2. Therefore, since the probe light scanned from the lower light receiving / emitting device 3b is scanned at a higher position than the probe light scanned from the upper light receiving / emitting device 3a, a light-shielding object, which will be described later, is an insert for indicating coordinates. Is inserted, the probe light scanned from the lower light emitting and receiving device 3b is blocked earlier.

Further, a retroreflective sheet 7, which is a retroreflective member, is provided substantially perpendicularly to the surface of the computer display D on the inner side of the coordinate input device 1 except for the lower part of the coordinate input area 2. It is provided so that it becomes.
Further, as shown in FIG. 2, the retroreflective sheet 7 is provided at a position that does not directly interfere with the probe light scanned from the upper light receiving and emitting device 3a. This retroreflective sheet 7
Has a characteristic of reflecting incident light toward a predetermined position regardless of the incident angle. More specifically, for example, the probe light p emitted from the upper light receiving / emitting device 3a
Numeral 1 is reflected by the retroreflective sheet 7 in the coordinate input area 2 and travels toward the upper light emitting / receiving device 3a as retroreflected light p1 'that follows the same optical path again. Similarly, the probe light p2 emitted from the lower light receiving / emitting device 3b is reflected by the retroreflective sheet 7 in the coordinate input area 2, and returns as the retroreflected light p2 'that follows the same optical path again. Proceed toward.

The retroreflected light reflected by the retroreflective sheet 7 and returned to the polygon mirror 6 is turned back by the half mirror 5 and condensed by passing through the condenser lens 8.
The light is received by the light receiving element 9. The light receiving element 9 is configured by, for example, a PIN photodiode, converts the received optical power of the retroreflected light into an electric signal (output voltage value), and outputs the electric signal as a light receiving signal. Note that the output light receiving signal is a “H (HIGH)” level signal having a high output voltage value when the retroreflection light is received, and a low output voltage value when the retroreflection light is not received. L (LOW) "
This is a level signal.

On the other hand, a reflection mirror 10 as a reflection member is provided inside the coordinate input device 1 and below the coordinate input area 2. In the reflection mirror 10, for example, the probe light p3 scanned from the upper light receiving / emitting device 3a is reflected by the reflection mirror 10 and travels to the retroreflective sheet 7, and is reflected by the retroreflective sheet 7 again to have the same optical path. (See FIG. 2) so as to travel toward the upper light-emitting / receiving device 3a as retroreflection light p3 ′ following the surface of the computer display D (see FIG. 2). Further, as shown in FIG. 2, the reflection mirror 10 is provided at a position that does not directly interfere with the probe light scanned from the lower light receiving and emitting device 3b. Further, a light-shielding plate 11 made of an opaque material is provided on a side edge of the reflection mirror 10. The light shielding plate 11 is for preventing disturbance light from a lighting fixture or the like from directly entering the reflection mirror 10. Thus, by preventing the disturbance light from being directly incident on the reflection mirror 10, the generation of scattered light is prevented, and the generation of light reception noise in the light receiving element 9 is prevented.

An arithmetic unit 12 is connected to the light receiving element 9. The calculation unit 12 detects the position coordinates (x, y) of the light-shielding object inserted into the coordinate input area 2 based on the light receiving signal from the light receiving element 9.

Next, the electrical connection of each part built in the coordinate input device 1 will be described with reference to FIG. The coordinate input device 1 includes a microcomputer 13 which controls each unit, and an interface (I
/ F) 14 is connected to a personal computer. The microcomputer 13 includes a CPU 15 for centrally controlling each unit, a ROM 16 for storing fixed data such as a control program in advance,
The RAM 17 functions as a work area for storing variable data in a rewritable manner. The microcomputer 13 is connected to the LD 4, the light receiving element 9, the timer T, the motors M 1 and M 2 for driving the polygon mirrors 6 of the respective light receiving and emitting devices 3, the arithmetic unit 12, and the like.

The microcomputer 13 controls the light emission timing of the LD 4 and the drive timing of the motors M1 and M2 by pulse control, so that the laser light emitted from the LD 4 is radially converted into parallel probe light along the surface of the coordinate input area 2. Is repeatedly scanned. Here, FIG. 4 is a front view schematically showing probe light emitted from the upper light receiving / emitting device 3a,
FIG. 5 is a time chart showing the relationship between the received light signal and the pulse signal of the probe light, FIG. 6 is a front view schematically showing the probe light emitted from the lower light receiving and emitting device 3b, and FIG. 5 is a time chart illustrating a relationship between a light receiving signal and a pulse signal. As shown in FIGS. 4 and 5, in the present embodiment, the probe light emitted from the upper light receiving and emitting device 3a and scanning the coordinate input area 2 is divided into 13 directions based on the pulse signal. . Further, as shown in FIGS. 4 and 5, when there is no light-shielding object that blocks the probe light in the coordinate input area 2, the light receiving signal output from the light receiving element 9 is a light receiving signal of “H” level. It is. On the other hand, as shown in FIGS. 6 and 7, in the present embodiment, the probe light emitted from the lower light receiving / emitting device 3b and scanning the coordinate input area 2 is transmitted to the upper light receiving / emitting device 3a.
The light is divided into ten directions based on the pulse signal so as to pass through the intersection of the probe light from the mirror and the probe light reflected by the reflection mirror 10. That is, there are three scanning lights emitted from the two light receiving and emitting devices 3a and 3b in the coordinate input area 2, and the coordinate input positions of the coordinate input device 1 of the present embodiment are those three. It is the position where the probe light crosses (intersection point). In addition, as shown in FIGS. 6 and 7, when there is no light-shielding object that blocks the probe light in the coordinate input area 2, the light receiving signal output from the light receiving element 9 is a light receiving signal of “H” level. It is.

The ROM 16 stores a memory table 18 and a memory table 19 together with a control program. Here, FIG. 8 is a schematic diagram showing a memory table 18 stored in the ROM 16, and FIG. 9 is a schematic diagram showing a memory table 19 stored in the ROM 16. As shown in FIG. 8, the memory table 18 stores the reflection mirror 1
0 and the upper light receiving / emitting device 3a
The pulse number M of the reflected probe light reflected by the reflecting mirror 10 and the pulse number N of the probe light from the upper light receiving / emitting device 3a when a light shield is inserted at the intersection with the probe light from The position coordinates (X, Y) corresponding to each combination are stored.

On the other hand, as shown in FIG. 9, the memory table 19 has a lower portion when a light shielding material is inserted at the intersection of the probe light from the lower light receiving and emitting device 3b and the probe light from the upper light receiving and emitting device 3a. The pulse number L of the probe light from the side light receiving and emitting device 3b and the pulse number N of the probe light from the upper light receiving and emitting device 3a are respectively combined in a matrix, and the position coordinates (X, Y) corresponding to each combination are combined. ) Is stored.

The microcomputer 13 detects a light receiving signal output from the light receiving element 9 and stores the position coordinates (x, y) of the light shielding object inserted in the coordinate input area 2 in the ROM 16. The calculation unit 12 is caused to detect based on the table 18. Here, detection of the position coordinates (x, y) by the microcomputer 13 when the operator points on the computer display D with a fingertip will be described. Here, FIG. 10 is a front view showing an example of a state where a predetermined position in the coordinate input area 2 is pointed out, and FIG. 11 is a time chart showing a relationship between a light receiving signal of the probe light and a pulse signal. For example, as shown in FIG. 10, when an appropriate position (x, y) on the computer display D is pointed by the fingertip A of the operator via the coordinate input area 2 of the coordinate input device 1, the fingertip A is The upper light receiving and emitting device 3a becomes a light shielding material.
Probe light b scanned fifth from (pulse number 5)
Probe light b 'reflected by the reflection mirror 10 of the above, and the probe light d scanned eleventh from the upper light receiving and emitting device 3a
(Pulse number 11) is blocked by the fingertip A.
Therefore, the probe lights b and d blocked by the fingertip A
Does not reach the retroreflective sheet 7, the retroreflected light of the probe lights b and d is not received by the light receiving element 9 of the upper light receiving / emitting device 3a. That is, in this case, no light receiving signal is output from the light receiving element 9. Therefore, as shown in FIG. 11, the light receiving signals at pulse numbers 5 and 11 are at the “L” level. The calculation unit 12 calculates the combination of these “L” level pulse numbers ((pulse number M, pulse number N) = (5,
11)), by searching the memory table 18, the position coordinates (x, y) pointed by the fingertip A
Is detected. Here, the function of the coordinate detecting means is executed. The position coordinates (x, y) detected in this way are represented by I / F
The data is transferred to a personal computer or the like via the PC 14 and is used for processing such as displaying a designated position by the fingertip A and inputting a command corresponding to the designated position.

Next, appropriate positions (x, y) and (x ', y') on the computer display D are indicated by the fingertips A and B of the operator via the coordinate input area 2 of the coordinate input device 1. Think about the case. Here, FIG.
FIG. 13 is a front view showing an example of a state where two predetermined positions in the coordinate input area 2 are simultaneously pointed out, and FIG. 13 is a time chart showing the relationship between the light receiving signal of the probe light emitted from the upper light emitting and receiving device 3a and the pulse signal. It is a chart. For example, FIG.
As shown in the figure, an appropriate position (x, x) on the computer display D via the coordinate input area 2 of the coordinate input device 1
y) with the operator's fingertip A, and at the same time (x ', y
When ') is pointed by the fingertip B of the operator, the fingertips A and B become light-shielding objects, and the reflection mirror 10 reflects the probe light b (pulse number 5) scanned fifth from the upper light emitting / receiving device 3a. The reflected probe light b 'and the probe light d (pulse number 11) scanned eleventh from the upper light receiving and emitting device 3a are blocked by the fingertip A, and the probe scanned third from the upper light receiving and emitting device 3a. Light a
The probe light a '(pulse number 3) reflected by the reflection mirror 10 and the probe light c (pulse number 9) scanned ninth from the upper light receiving / emitting device 3a are blocked by the fingertip B. Therefore, the probe light beams b and d blocked by the fingertip A and the probe light beams a and
Since c does not reach the retroreflective sheet 7,
The retroreflected light of the probe lights a, b, c, and d is not received by the light receiving element 9 of the upper light receiving and emitting device 3a. That is,
In this case, no light receiving signal is output from the light receiving element 9. Therefore, as shown in FIG. 13, the light receiving signal at pulse number 3, pulse number 5, pulse number 9, and pulse number 11 is at the “L” level.

However, in the above-described state, two "L" level light receiving signals are detected from each probe light, so that in addition to the actual cutoff points A and B,
Points A ′ and B ′ may be erroneously recognized (FIG. 1).
2). That is, the combination of the pulse signals based on the “L” level light receiving signal is A (pulse number M, pulse number N) = (5, 1
1) A '(pulse number M, pulse number N) = (3,1
1) B (pulse number M, pulse number N) = (3, 9) B ′ (pulse number M, pulse number N) = (5, 9) Can not.

Therefore, when two predetermined positions in the coordinate input area 2 are indicated at the same time, the lower light emitting / receiving device 3b
The light receiving signal output from the light receiving element 9 is detected based on the probe light scanned from. As shown in FIG.
In this case, the probe light e (pulse number 6) scanned sixth from the lower light receiving and emitting device 3b is blocked by the fingertip A, and the probe light f scanned eighth from the lower light receiving and emitting device 3b. (Pulse number 8) is blocked by the fingertip B. Therefore, the probe light f blocked by the fingertip A and the probe light e blocked by the fingertip B
Does not reach the retroreflective sheet 7, the retroreflected light of the probe lights e and f is not received by the light receiving element 9 of the lower light receiving and emitting device 3b. That is, in this case, no light receiving signal is output from the light receiving element 9. Therefore, as shown in FIG. 14, the light receiving signals at pulse numbers 6 and 8 are at the “L” level.

Next, the arithmetic section 12 is operated by the lower light receiving / emitting device 3b.
And the combination of the “L” level pulse number in the above and the “L” level pulse number in the upper light emitting / receiving device 3a described above ((pulse number L, pulse number N) = (6,
9), (6, 11), (8, 9), and (8, 11)), the memory table 19 is searched. In this case, FIG.
As shown in FIG. 2, both the point B and the point B ′ are located on the light beam of the probe light e, but based on (pulse number L, pulse number N) = (8, 11) by the memory table 19. Coordinates (x, y) indicated by the fingertip A
Is detected, and since the remaining pulse number L is “6”, the position coordinates (x ′, y) indicated by the fingertip B are determined.
') Is also detected. Here, the function of the coordinate detecting means is executed. The position coordinates (x, y) thus detected and (x
', Y') are transferred to a personal computer or the like via the I / F 14, and are used for processing such as display of designated positions by the fingertips A and B and input of commands corresponding to the designated positions.

Next, step-by-step optical scanning means, which is a function executed by the microcomputer 13 by the control program stored in the ROM 16 and which is a characteristic function of the coordinate input device 1 of the present embodiment, will be described below. I do. Here, FIG.
5 is a flowchart schematically showing the flow of the stepwise optical scanning process.

As shown in FIG. 15, first, only the lower side light emitting / receiving device 3b is driven to start optical scanning (step S1). Next, in step S2, the process waits until the probe light scanned from the lower light receiving and emitting device 3b is blocked by the light shielding material.

When it is determined based on the received light signal that the probe light scanned from the lower light receiving / emitting device 3b is blocked by the light shielding material (Y in step S2), the upper light receiving / emitting device 3a is driven to emit light. Scanning is started (step S
3).

Subsequently, an interruption point is detected based on the light receiving signal of the probe light (step S4), and the position coordinates (x, y) of the light-shielding object based on the detected interruption point are calculated by the calculation unit 12.
And is displayed on the computer display D (step S5).

Thereafter, as long as it is determined based on the light receiving signal that another probe light scanned from the lower light receiving / emitting device 3b has been blocked by the light shielding material (Y in step S6).
Steps S4 to S5 are repeated. Further, a state in which the probe light scanned from the lower light receiving / emitting device 3b is not blocked by the light shielding material (N in step S6)
When the elapse of the predetermined time is measured by the timer T (N in step S7), the driving of the upper light emitting / receiving device 3a is stopped (step S8), and the scanning is performed again from the lower light emitting / receiving device 3b in step S2. It waits until the probe light is blocked by the light shielding material.

By such processing, only the lower light emitting / receiving device 3b is driven without driving the upper light receiving / emitting device 3a during standby for insertion of the light blocking object, and the probe light scanned from the lower light emitting / receiving device 3b is driven. By driving the upper light emitting and receiving device 3a immediately after being blocked by the light shielding material, the driving of the upper light receiving and emitting device 3a is started immediately before the insertion of the light shielding material, so that the probe light scanned from the upper light receiving and emitting device 3a is also shielded. It will be blocked by objects. As a result, power consumption during standby for insertion of the light-shielding object into the coordinate input area 2 is saved, and the coordinate input device 1 having a long device life can be obtained.

In addition, detection of a cutoff point based on a light reception signal of a probe light scanned from the lower light receiving / emitting device 3b, and detection of a cutoff point based on a light reception signal of the probe light scanned from the upper light receiving / emitting device 3a. Is processed with a time difference, so that the load of the calculation processing in the calculation unit 12 is reduced as compared with the case where the cutoff point is detected at once based on both light reception signals.

In the present embodiment, the upper and lower light receiving and emitting devices 3a and 3b are provided on the diagonal line of the coordinate input area 2, but the present invention is not limited to this. On the same side, one of the upper and lower light receiving and emitting devices 3a and 3b may be provided so as to be located on the reflection mirror 10 side. With this arrangement, the scanning direction of the probe light scanned from the lower light emitting and receiving device 3b and the scanning direction of the probe light scanned from the upper light receiving and emitting device 3a do not lie on the same straight line. .

Further, in the present embodiment, the position coordinates (x, y) indicated by the light shielding object are detected by searching the memory table 18 and the memory table 19 based on the pulse number of the probe light. However, the present invention is not limited to this, but detects the number of pulses of the motors M1 and M2 when scanning each blocked probe light based on the pulse number of the probe light, and emits each probe light based on this pulse number. The angle may be calculated, and the position coordinates (x, y) indicated by the light-shielding object may be calculated based on the principle of triangulation based on the emission angles of the respective probe lights.

Further, in the present embodiment, the probe light emitted from the upper light emitting / receiving device 3a and scanning the coordinate input area 2 is divided into 13 directions based on the pulse signal, and the lower light receiving / emitting device 3a is divided into 13 directions. The probe light emitted from 3b and scanning the coordinate input area 2 is divided into ten directions based on the pulse signal. However, the present invention is not limited to this, and the division direction may be increased by dividing the probe light more finely. Then, the dividing direction may be reduced. Actually, fingers and pens that are light-shielding objects have a certain size,
There is no need to be overly overcrowded.

In the present embodiment, the coordinate input device 1 is mounted on the computer display D. However, the present invention is not limited to this, and any display device for displaying image data may be used. It may be mounted on a device having a surface.

[0048]

According to the first aspect of the present invention, in the coordinate input area, the reflected light reflected by the reflecting member reflects the light beam scanned from the first light emitting device provided opposite the reflecting member. Beam, a light beam scanned from the second light emitting device, and the presence of three scanning lights emitted from two light emitting devices composed of the light beam scanned from the first light emitting device, If two inserts are inserted at the same time at the intersection of the three scanning beams to block each light beam,
Even if three light emitting devices are not provided, the position coordinates where the inserts are inserted can be detected based on the light receiving signals output by the respective light receiving elements. Can be detected.

According to the second aspect of the present invention, in the coordinate input device according to the first aspect, the height position of the scanning in the coordinate input area of the light beam scanned from each light emitting device is made different from the first position. Processing with a time difference between detection of a cutoff point based on a light reception signal of a light beam scanned from the light emitting device and detection of a cutoff point based on a light reception signal of a light beam scanned from the second light emission device Therefore, the load of the arithmetic processing can be reduced as compared with the case where the cutoff point is detected at once based on both light receiving signals.

According to the third aspect of the present invention, in the coordinate input device according to the first or second aspect, the light shielding plate is provided on a side edge of the reflecting member to block external light rays directly incident on the reflecting member. Therefore, generation of scattered light by the reflection member can be prevented, and generation of light reception noise in the light receiving element can be prevented.

According to the fourth aspect of the present invention, in the coordinate input device according to any one of the first to third aspects, the first light emitting device is not driven during standby for insertion of an insert into the coordinate input area. Only the second light-emitting device is driven, the first light-emitting device is driven immediately after the light beam scanned from the second light-emitting device is cut off by the insert, and the first light-emitting device is immediately before the insertion of the insert. By starting the drive of the first light emitting device, the light beam scanned from the first light emitting device can also be blocked by the insert, so that it is possible to save power consumption during standby for insertion of the insert into the coordinate input area. , The life of the device can be extended.

[Brief description of the drawings]

FIG. 1 is a front view schematically showing a configuration of a coordinate input device according to an embodiment of the present invention.

FIG. 2 is a side view thereof.

FIG. 3 is a block diagram showing an electrical connection of each unit built in the coordinate input device.

FIG. 4 is a front view schematically showing probe light emitted from the upper light receiving and emitting device.

FIG. 5 is a time chart showing a relationship between a light receiving signal of the probe light and a pulse signal.

FIG. 6 is a front view schematically showing probe light emitted from the lower light receiving and emitting device.

FIG. 7 is a time chart showing a relationship between a light receiving signal of the probe light and a pulse signal.

FIG. 8 is a schematic diagram showing a memory table stored in a ROM.

FIG. 9 is a schematic diagram showing a memory table stored in a ROM.

FIG. 10 is a front view showing an example of a state in which a predetermined position in a coordinate input area is pointed out.

FIG. 11 is a time chart showing a relationship between a light receiving signal of the probe light and a pulse signal.

FIG. 12 is a front view showing an example of a state where two predetermined positions in the coordinate input area are simultaneously pointed out.

FIG. 13 is a time chart illustrating a relationship between a light receiving signal of the probe light emitted from the upper light receiving and emitting device and a pulse signal.

FIG. 14 is a time chart showing a relationship between a light receiving signal of the probe light emitted from the lower light receiving and emitting device and a pulse signal.

FIG. 15 is a flowchart schematically showing a flow of a coordinate detection process.

FIG. 16 is a front view schematically showing a conventional coordinate input device.

FIG. 17 is a front view showing a situation where two points are simultaneously designated in the coordinate input area of the coordinate input device.

FIG. 18 is a time chart showing a relationship between a light receiving signal and a pulse signal in each light scanner when two points are instructed simultaneously.

[Explanation of symbols]

 1a housing 2 coordinate input area 3a first light emitting device 3b second light emitting device 4 light source 7 retroreflective member 9 light receiving element 10 reflecting member 11 light shielding plate A, B insert

Claims (4)

[Claims] A rectangular frame-shaped housing; a reflecting member disposed on one side of an inner periphery of the housing; and a light source provided at an end of one side of the inner periphery of the housing opposed to the reflecting member. A first light emitting device that radially scans each light beam emitted from the light source toward the inside of the housing, and is provided at an end of one side of the inner circumference of the housing where the reflecting member is provided. A second light emitting device having a light source and radially scanning each light beam emitted from the light source toward the inside of the housing; and formed by intersection of each light beam scanned from these light emitting devices. A coordinate input area for receiving insertion of an insert indicating coordinates, and a peripheral part of the coordinate input area, which is disposed on three sides of the inner periphery of the housing except for one side on which the reflective member is disposed, A retroreflective device that retroreflects the light beam scanned from each light emitting device. A member, provided on each light emitting device, for receiving a light beam retroreflected by the retroreflective member, converting the optical power of the received light beam into an electric signal and outputting it as a light receiving signal, A light beam scanned from the second light emitting device, a light beam scanned from the first light emitting device, and a reflected light beam reflected by the reflecting member when the light beam scanned from the first light emitting device is reflected. When one or two of the inserts are inserted at the intersections in the coordinate input area with the beam to block each light beam, the position coordinates at which the inserts are inserted are based on the light receiving signals output by the light receiving elements. A coordinate input device comprising: 2. A light beam scanned from the first light emitting device and a light beam scanned from the second light emitting device have different scanning height positions in the coordinate input area. Coordinate input device. 3. The coordinate input device according to claim 1, further comprising a light-shielding plate provided on a side edge portion of said reflection member, for blocking external light beams directly incident on said reflection member. 4. During standby for insertion of the insert into the coordinate input area, only the second light emitting device is driven without driving the first light emitting device, and scanning is performed from the second light emitting device. The coordinate input device according to any one of claims 1 to 3, further comprising a stepped light scanning unit that drives the first light emitting device immediately after a light beam is blocked by the insert.