JPS61221923A - Perspective type inputting device - Google Patents

Abstract

PURPOSE:To discriminate whether an abnormality is caused by abnormality of a photodetecting element or the abnormality of a light emitting element where the ON/OFF state of the photodetecting element is not equal to an estimated state by detecting said ON/OFF state. CONSTITUTION:It is supposed that an LED 11 which should be kept ON is turned off owing to the abnormality either of the LED 11 or a phototransistor PHT 21 in a state where the optical path of an infrared ray L1 is cut off. Under such conditions, an LED 12, for example, that possibly turns on the PHT 21 is turned on and at the same time the state of the PHT 21 is checked. If the PHT 21 is kept OFF, it is decided that the LED 11 is normal and the PHT 21 is broken. While it is decided that the LED 11 is broken and the PHT 21 is normal if the PHT 21 is turned on. The lighting control and the abnormality judgement of the LED are carried out by the microcomputer of a control part 3.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a light emitting device that transmits and receives light across a display screen.
The present invention relates to a see-through type input device in which a large number of pairs of light-receiving elements are arranged, and an operator inputs information by touching a display screen and blocking light.

[Technical background of the invention and its dark problems]

This type of transparent input device is used as a man-machine interface for measurement control systems, and as shown in FIG. 10 and phototransistor (hereinafter abbreviated as P!-I■) JIY 40
are arranged in a row in the left-right direction while being mounted on a printed circuit board, and a PHT group 20 and an LED group 30 are arranged in a row in the left-right direction on the upper side of the CR7 display screen 1. Then, the LEDs arranged in order 1.12.・
in.

...and PHT21, 22. . . 2n, . . . are opposed to each other and form a pair of light emitting and light receiving elements that transmit and receive light across the CRT display screen.

In addition, L E placed on the left side of the CRT display screen 1
Group D 50 and PHTI! ¥80 and CRT display screen 1
PHT group 60 and LED group 7 arranged on the right side of
A similar pair of light emitting and light receiving elements is formed by the group 0.

In this way, the LED lights P forming a pair of light emitting and light receiving elements
) All ITs are connected by cables 2 to IIJ m I 3, also called control board.

This control section 3 is composed of a microcomputer, and when an operator touches the display screen to block light, the information is taken into the control section 3.

In such a see-through type input device, since the infrared rays generated from the LED are invisible, it is difficult to judge whether the LED is lit or not.
If any of LEDI 21 fails and PHT21 does not reach the expected state, it is assumed that LEDI 1 has failed.
-There was a problem in that it was not possible to determine whether or not IT 21 had malfunctioned.

(Purpose of the Invention) The present invention has been made to solve the above-mentioned problems. The object of the present invention is to provide a see-through type human power 8E that can easily determine whether a light emitting element that is turned on or a light emitting element that is likely to be turned on is abnormal.

(IN Essentials of the Invention) In order to achieve this object, the present invention has a plurality of pairs of light emitting and light receiving elements arranged in large numbers, as shown in the block diagram of FIG.
1, an abnormality detection means 102 that detects a light receiving element whose on or off state is not in the expected state; a lighting control means 103 that controls a light emitting element that may cause the light receiving element to be turned on; The on/off state of the element and the light receiving element paired with the light emitting element is detected, and the on/off state of the light receiving element paired with the light emitting element is detected.
Is the light-receiving element not in the expected off state abnormal?
The device includes an abnormality determining means 104 that determines whether the light-emitting element that causes the light-receiving element to be turned on or the light-emitting element that is likely to be turned on is abnormal.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG.

First, let us assume that LEDl 1, which should normally be on, remains off because either LEDll or PHT2i has become abnormal, even though the optical path of infrared rays 1 is not blocked. . In this case PH72
LED l2.13 that can cause 1 to turn on
...For example, turn on LEDl2 and press P
Check the on/off status of HT21. At this time, PH7
If 21 remains off, it is determined that 1ED11 is normal and PH721 is destroyed. Also,
On the contrary, if P l-I T 21 changes to the on state, it is determined that LED l 1 is destroyed and PH 721 is normal. Such LED lighting control and abnormality determination, including abnormality detection, are performed by software of the microcomputer that constitutes the control unit 3.

In addition, in the above-mentioned LED'D lighting control, PHT2
It can be said that any LED that can turn on the infrared light L1°L2. L3. ...
Considering the directivity of the LED, it is most advantageous to light the adjacent LED 12 in that it can provide sufficient light transmission to the PHT 21.

Next, even though the infrared light path of 1 was blocked, the LED
Assume that l1 is turned on. In this case, P
LEDl2 that can cause HT 21 to turn on
．． A signal is given to turn off all of PHTs 13, 23, . Here, if all of PHT22, 23°...2n are off, all LEDs are normal, and PHT21
It is determined that there is a short circuit. Also, on the contrary,
PHT22.23. ...If any one of 2n is in the on state, the corresponding LED is lit, but in this case, one P l-I T
If only one PHT is on, it is determined that the corresponding LED is destroyed, and if a plurality of PHTs are on, it is determined that the LED paired with the central PHT is destroyed.

By the way, the control device 3 consisting of a microcomputer is
When it is detected that the on/off state is not the expected state, the abnormality is notified to the operator by some means. When the operator puts the control device 3 into the test mode, the above-mentioned lighting control and abnormality determination are performed.

In the above embodiment, the light emitting and light receiving element pairs are 1 to ED,
! Although the description has been made regarding a see-through type input device configured with PHT, the present invention is not limited thereto, and can also be applied to a see-through type input device using a lamp as a light emitting element and a photodiode as a light receiving element. It is something.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, when a light-receiving element that is not in the expected ON or OFF state is detected, the light-emitting element that has the possibility of turning this light-receiving element into the ON state is controlled, and The light-receiving element is not in the
By detecting the on/off state of the light-receiving element paired with the light-emitting element, it is possible to determine whether the light-receiving element itself, which is not in the expected state, is abnormal, or whether the light-emitting element or the Since it is determined whether a light emitting element that may be in a state of abnormality is determined, it is possible to extremely easily determine which element is malfunctioning, which was difficult to do with conventional devices.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention, and FIG. 2 is an explanatory diagram of the configuration of a general perspective input device. DESCRIPTION OF SYMBOLS 1... Display screen, 2... Cable, 3... Control unit, 10.30, 50.70... Light emitting diode group, 2
0.40.60.80...E1~Transistor group, 1
1.12~1n...Light emitting diode, 21.22~2
n...Hol-transistor. Applicant's agent Kiyoshi Inomata Figure 2

Claims (1)

[Claims] In a see-through type input device in which a large number of pairs of light emitting and light receiving elements are arranged to transmit and receive light across a display screen, and information is input by touching the display screen and blocking the light,
Abnormality detection means for detecting a light-receiving element that is not in an expected off state; and lighting control means for controlling a light-emitting element that may turn on the light-receiving element based on an output signal of the abnormality detection means. Then, the on/off state of the light receiving element and the light receiving element paired with the light emitting element is detected, and the light receiving element whose on/off state is not in the expected state is abnormal or this light receiving element is detected. What is claimed is: 1. A see-through type input device comprising: abnormality determining means for determining whether a light emitting element that is turned on or a light emitting element that is likely to be turned on is abnormal.