JP2003091357A - Coordinate input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coordinate input device for assuring safety by detecting earlier destruction or breakage and the abnormal condition of a light and cutting off a power supply for a light source part before exceeding a class 1, and for giving no poor influences on the operation of equipment in such a case. SOLUTION: The coordinate input device comprises two light source parts installed at different places on a touch panel 101 for emitting lights approximately parallel to the touch panel and around installation positions, reflection parts 103A, 103B, 103C installed on the touch panel 101 for reflecting the lights from the light source parts toward the light source parts, and light receiving parts installed at the installation positions of the light source parts for receiving the reflected lights from the reflection parts 103A, 103B, 103C, the light source parts and the light receiving parts being formed as one each of optical units 102A, 102B. When the light is shielded by a shield such as a finger, the shielded position is detected. A light monitoring light receiving element 11 is installed for monitoring the lights from the light source parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate input device, and more particularly to a touch panel with a large screen device, an electronic blackboard,
The present invention relates to an optical coordinate input device applicable to a video conference system, a large-sized projection touch panel, a display body type tablet, and the like.

[0002]

2. Description of the Related Art Generally, in an optical coordinate input device or the like, light used as a light source thereof is light from a semiconductor laser diode (hereinafter referred to as LD). This LD
In some cases, light may adversely affect the human body, so the intensity of the light is classified according to JIS and displayed on the device to notify the user of its content. .

[0003]

When the light source unit used in the optical coordinate input device is LD light, the light is emitted to the outside of the device, so the safety to the human body must be considered first. The class 1 is a condition for the LD light used for the light source. Further, when the LD light is used in a fan shape as in the present device, the LD light is diffused, so that a sufficient margin can be secured with respect to the class 1 and the human body is not adversely affected. ing.

However, depending on the LD to be used, the light emitted when the LD is destroyed or damaged (optical destruction output) may have a very high output for some reason, and at this time, it may exceed Class 1. Yes, and in some cases, classes 3 and 3B are possible, which is dangerous.

The present invention has been made in view of the above circumstances, and an object thereof is to detect a breakage / damage and an abnormal light state as soon as possible, and to supply power to a light source unit before exceeding Class 1. It is possible to provide a coordinate input device that can ensure safety by shutting off the device and that does not adversely affect the operation of the device even in that case.

[0006]

In order to solve the above-mentioned problems, the invention described in claim 1 is installed at different positions of a touch panel, and emits light substantially parallel to the touch panel and centered on the installation position. Two light source units, a reflection unit that is installed on the touch panel and reflects light from the light source unit toward the light source unit, and a reflection unit that is installed at each installation position of the light source unit and receives reflected light from the reflection unit. And a light-receiving unit for controlling the light-source unit and the light-receiving unit as one optical unit, and when light is shielded by a shield such as a finger,
In the coordinate input device that detects the shielded position,
An optical monitoring light receiving element for monitoring the light of the light source unit is installed.

According to the invention described in claim 1,
Light (LD light, etc.) because a light receiving element for light monitoring is installed
The state of can be always grasped, the abnormality of the light can be recognized, and the response for ensuring the safety can be done promptly.

The invention described in claim 2 is characterized in that, in the invention described in claim 1, the light receiving element is incorporated in the optical unit.

According to the invention described in claim 2,
While the same effect as the invention of claim 1 is obtained,
Since the light receiving element is installed inside the optical unit, it does not require extra space outside the unit, and is directly affected by ambient light (LD light, etc.) more than when it is installed outside the optical unit. Can be monitored and the safety as a unit can be secured.

According to a third aspect of the present invention, in the invention according to the first aspect, the light receiving element is installed at a predetermined inclination angle other than 90 ° with respect to the light incident on the light receiving element. It is characterized by being

According to the invention described in claim 3,
While the same effect as the invention of claim 1 is obtained,
Since the light receiving element is installed so as to be inclined with respect to the incident light, the surface reflected light by the surface of the light receiving element does not enter the light receiving portion, and there is no erroneous detection in the light receiving portion.

According to a fourth aspect of the present invention, in the first aspect of the invention, the power supply line supplied to the light source unit is shut off according to the state of light received by the light receiving element. To do.

According to the invention described in claim 4,
While the same effect as the invention of claim 1 is obtained,
By monitoring the light by the light receiving element and turning off the power source of the light source unit before a dangerous state is reached, it is possible to quickly secure safety.

According to a fifth aspect of the present invention, in the first aspect of the invention, the light receiving element operates independently without an arithmetic unit.

According to the invention described in claim 5,
While the same effect as the invention of claim 1 is obtained,
Since there is no arithmetic unit, and it operates at the same time when the power is turned on, even if there is an abnormality due to a runaway of the arithmetic unit,
The light receiving element is not affected at all and can be operated to constantly monitor light and ensure safety.

[0016]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

The overall structure of the coordinate input device according to one embodiment of the present invention is shown in FIG. The coordinate input device according to the present embodiment is installed in different positions of the touch panel 101, and is installed in the touch panel 101 and two light source units that emit light substantially parallel to the touch panel 101 and centered on the installation position. Reflecting portions 103A, 103B, 103C that reflect the light from the light source portion toward the light source portion, and the reflecting portion 103 that is installed at the installation position of the light source portion.
It has a light receiving part 11 (see FIG. 2) for receiving the reflected light from A, 103B, 103C, and the light source part and the light receiving part 11 are one unit (hereinafter referred to as an optical unit), and light is shielded by a finger or the like. When the object is shielded, the shielded position is detected.

Specifically, the optical units 102A and 102B are provided at both ends of the lower portion of the touch panel 101, and the optical units 102A and 1B are provided at the left and right sides and the upper side of the touch panel 101.
The reflecting units 103A, 103B, 103C that reflect the fan-shaped light emitted from the 02B toward the emitted light source are arranged to drive the optical units 102A and 102B and to receive light from the light receiving unit 204 (see FIG. 2) of the optical unit. It has a calculation unit 104 that inputs a signal and calculates a coordinate position and an interface unit 105 that outputs the calculated coordinate value. The coordinate value is displayed on the touch panel 101 through the personal computer PC.

As shown in FIG. 2, the optical unit 10
2A and 102B are a light source 201, a lens 202 that diffuses the light emitted from the light source 201 in a fan shape, and a reflection unit 10.
The lens 203 receives the reflected light from 3A, 103B, and 103C, and the light receiving part 204. By using these as one unit, the alignment (distance and center alignment) of the light source and the light receiving unit can be adjusted in units of units, which allows easy adjustment.

FIG. 3 shows a state in which the optical monitoring light receiving element 11 for monitoring the light of the light source section is installed in the optical unit. The installation position must be a position where the LD light emitted in a fan shape and the light receiving line of the light receiving unit are not blocked. Blocking each of these lines results in detection of coordinates by the light receiving unit, and thus the basic function of the present device does not work.

In the optical unit, due to the structure, the LD light A from the light source part becomes the light B which passes through the half mirror 205 and is emitted to the outside of the unit. At this time, due to the characteristics of the half mirror 205 used here, only 50% of the LD light A passes, and the remaining 50% of the light C is 45 ° (angle θ).
Because the half mirror is installed with the inclination of 1), the characteristics of the mirror and the inclination installation of 45 ° (angle θ1)
It is injected in the upper C direction. At this time, in order to utilize the emitted light, the light receiving unit 11 is installed at a position on the extension of the light C.

FIG. 4 shows the LD light C incident on the light receiving element 11.
On the other hand, it is a diagram installed at a right angle. The surface of the light receiving element 11 is often flattened with glass or the like, and the received light C is incident on the light receiving element 11 and at the same time, the light receiving element 1
If there is light that 1 receives, depending on the surface of the light receiving element 11,
There is also light D that is reflected. At this time, the light receiving element 11 is replaced by the light receiving portion 2
04 and the lens 203 are installed at a right angle, the reflected light D is characteristic of the half mirror 205 (light from A to B direction passes, but light from B to A direction does not pass). , The light receiving section 2 that passes through the half mirror
There is a risk that the light will enter the light source 04, which will be ambient light for the light-receiving portion, and in some cases, may cause erroneous detection.

Therefore, the light D reflected on the surface of the light receiving element 11
In order to prevent the incident light from entering the light receiving portion 204, it is necessary to provide an angle θ2 so that the surface reflected light D does not enter the light receiving portion 204, as shown in FIG. There is. At this time, although depending on the structure of the optical unit, in the case of the present embodiment, since the distance E from the half mirror 205 to the light receiving element is about 5 mm, at least the angle θ2 is about 9.5 °. The angle θ2 may be increased by + α in consideration of variations and margins of parts. Actually, it is set to 10 ° because of space limitations.

By the way, FIG. 6 is a diagram showing an example when the optical unit 102 is not installed. Optical unit 102
When trying to obtain LD light outside, the light receiving element 11 cannot be installed in the effective writing area 12. When installed, the light receiving element 11 does not have a reflection characteristic like a retroreflective plate,
The D light is not reflected and the light receiving unit recognizes it as coordinates. Therefore, it will be outside the effective writing area 12, and will be points A and B.

FIG. 7 shows a comparison between the installation of the light receiving element inside the optical unit and the installation outside the optical unit. Fan-shaped light 13
In relation to the light source, the central light is thick and strong, but becomes thinner and weaker toward the edges. At this time, the installation inside the optical unit becomes the point D, and the installation outside the optical unit becomes the point C. Therefore, when the optical unit is installed in the optical unit, a large and large output light can be obtained by the fan-shaped center installation.
A large amount of light can be received with respect to the area ratio of the D light 13, and if the area of the light receiving portion is large, more stable and intense light can be obtained. Outside the optical unit, very unstable light is received at the end of the LD light 13, and in some cases, ambient light may be brighter. At this time, the light receiving element 11 may enter erroneous light. I can't do it.

As described above, when the optical unit is installed in the optical unit, it is the place where the ambient light is least incident on the equipment and is not affected, and the LD light and the light receiving line are also present in the equipment. It is a very good position because the strongest light can be obtained at a position that does not block the light and is closest to the light. Safety can be ensured as a single optical unit, and classification can be applied.

FIG. 8 shows an example of a drive circuit for the light receiving element. 1
1 is a light receiving element, 20 is a reference voltage, 21 is a comparator,
22 is a light source power supply, 23 is an analog circuit, 24 is a light source, and 25 is a fuse. The light source unit 24 is supplied with the light source unit power source 22 via the SW 23. In addition, since the drive circuit uses the components that operate by turning on the power without the intervention of the operation unit, the drive circuit is independent of the operation unit 104, and independently when the operation unit 104 runs out of light, the light receiving element, and the surroundings. There is no circuit malfunction, and the safety circuit works even when the CPU runs out of control.

Regarding the operation of the example of the drive circuit, when the light receiving element 11 which is always receiving the LD light receives the high output LD light, a signal of a level corresponding to the light receiving level is output to the comparator 21. Is entered. In the comparator, with respect to the power supply to the light source unit, the level to be shut off is set in advance as the reference voltage 20. This is compared with the signal level from the light receiving element 11, and when the signal level exceeds the reference voltage 20, the signal from the comparator 21 becomes
By blowing the fuse 25 through the analog circuit, the light source unit 24, which has been supplied with the light source unit power source 22, is cut off from the power source and the operation is stopped so that the light source unit does not output light. In this case, since the power source of the light source unit 24 is cut off by the fuse, the light source unit 2 is not turned off when the power is turned on again.
It is safe because the light source that is abnormal or damaged due to the power supply of No. 4 does not emit light again.
A photodiode or the like is used as the light-receiving element, and a reference voltage is divided by a resistor, a reference reference voltage IC, or the like.

As described above, in the present embodiment, since the light monitoring light-receiving element 11 is installed, the state of the LD light can be always grasped, the abnormality of the LD light can be recognized, and the safety is ensured. Can respond quickly.

Further, in this embodiment, since the light receiving element 11 is installed in the optical unit, no extra space is required outside the unit, and it is more affected by ambient light than when it is installed outside the optical unit. LD light can be directly monitored without any incident, and safety as a unit can be secured.

Further, in the present embodiment, the light receiving element 11
Is installed so as to be inclined with respect to the incident light, the surface reflection light from the surface of the light receiving element 11 is prevented from entering the light receiving section 204, and the light receiving section 204 does not erroneously detect.

Further, in the present embodiment, since the light receiving element 11 can monitor the light and the power of the light source unit can be cut off before a dangerous state is reached, prompt safety can be ensured. .

Further, in the present embodiment, the light receiving element 11
Since the operation unit does not intervene, and it operates at the same time when the power is turned on, the light receiving element is not affected at all even when an abnormality occurs due to a runaway operation of the operation unit, and always monitors the light. Operation is possible to ensure safety.

[0034]

According to the invention described in claim 1, since the light receiving element for light monitoring is installed, the state of light (LD light etc.) can be always grasped, and the abnormality of light can be recognized. You can quickly respond to ensure safety.

According to the invention described in claim 2, the same effect as that of the invention of claim 1 can be obtained, and since the light receiving element is installed in the optical unit, an extra space is provided outside the unit. It is not necessary, and the light (LD light etc.) can be directly monitored without being affected by ambient light more than when it is installed outside the optical unit, and safety as a unit can be secured.

According to the invention described in claim 3, the same effect as that of the invention of claim 1 can be obtained, and the light receiving element is installed with an inclination with respect to the incident light.
Surface reflected light from the surface of the light receiving element does not enter the light receiving part,
There is no false detection in the light receiving part.

According to the invention described in claim 4, the same effect as that of the invention of claim 1 can be obtained, and the light is monitored by the light receiving element to prevent the danger from occurring.
Since the power of the light source unit can be cut off, it is possible to ensure quick safety.

According to the invention described in claim 5, the same effect as that of the invention of claim 1 can be obtained, and since the arithmetic unit is not present and the operation is performed at the same time when the power is turned on, for example, The light receiving element is not affected even when an abnormality occurs due to a runaway operation of the computing unit, and the light is constantly monitored,
Operation is possible to ensure safety.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a coordinate input device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of an optical unit of the coordinate input device of FIG.

FIG. 3 is a diagram showing an example of mounting a light receiving element.

FIG. 4 is a diagram showing one mounting example of a light receiving element.

FIG. 5 is a diagram showing a mounting example of the present invention of a light receiving element.

FIG. 6 is a diagram when a light receiving element is not installed in the optical unit.

FIG. 7 is a diagram showing a comparison between installation of the light receiving element inside the optical unit and installation outside the optical unit.

FIG. 8 is a drive circuit diagram of a light receiving element.

[Explanation of symbols]

11 Light receiving element for optical monitoring 101 touch panel 102A, 102B Optical unit 103A, 103B, 103C Reflector part 201 light source

Claims (5)

[Claims] 1. The touch panel is installed at different positions,
Two light source units that emit light substantially parallel to the touch panel and centered on the installation position; a reflection unit that is installed on the touch panel and reflects light from the light source unit toward the light source unit; And a light receiving unit that is installed at each of the installation positions and receives the reflected light from the reflecting unit, and the light source unit and the light receiving unit are configured as one optical unit,
In a coordinate input device for detecting the shielded position when light is shielded by a shield such as a finger, a light input device for light monitoring for monitoring the light of the light source unit is installed. apparatus. 2. The coordinate input device according to claim 1, wherein the light receiving element is incorporated in the optical unit. 3. The coordinate input device according to claim 1, wherein the light receiving element is installed with a predetermined inclination angle other than 90 ° with respect to the light incident on the light receiving element. 4. The coordinate input device according to claim 1, wherein the power supply line supplied to the light source unit is shut off according to a state of light received by the light receiving element. 5. The light receiving element, without interposing an arithmetic unit,
The coordinate input device according to claim 1, wherein the coordinate input device operates independently.