JPS5974591A - Display lighting circuit with disturbance detecting function - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display failure detection device, and more particularly to a display failure detection device suitable for a method of scanning and lighting a large number of arranged display lamps. There are various devices that use text panels that display characters, figures, etc. at the same time, and automatic cash dispensers are one of them. In this type of equipment, a detection circuit is installed to monitor abnormalities in the actuator system, and a program is monitored.However, a scanning lighting method is used to detect faults in the LBD and lamps installed in the customer operation section, attendant i operation section, etc.
Because the scale of the circuit would be extremely large, a separate test switch was installed for the operator to operate, and when the switch was turned on, all indicator lamps were turned on for visual confirmation. Therefore, although the staff regularly and visually monitor the wires, if the wire breaks during operation by a customer, etc., they will not be able to detect it and will continue to display it, and as a matter of course, the display function will not be fully fulfilled, and Not only did customers repeatedly make operational errors, but they also led to immediate equipment failure.

The present invention addresses the above-mentioned drawbacks of the prior art and consists in centrally monitoring the presence or absence of a failure in a plurality of display devices using a small number of detection circuits.

The present invention focuses on the fact that the display device for this rod has a block configuration in which a plurality of indicators are connected to a set of drive circuits and lights up and displays by scanning, and the IA dynamic current provided in the drive circuit is The detection circuit is designed to detect whether or not there is a disconnection on either side of the display by comparing the drive control signal with the drive current that actually flows.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 is a scanning lighting circuit diagram that controls up to 16 displays, in which 1 is a counter that counts the clock signal T, 2 is a decoder, 6°4 is a data selector, and 5.
6 is an open collector type driver, 7 to 10 resistors are provided at the decoder output, and transistors 11 to 140 are base resistors. 15 to 22 are indicators (LED), 2 rows,
This is a current limiting resistor for 1 indicator installed in the AI power of the 2A high driver 5.6. In addition, Dl and D4 are indicators 15 to 1, respectively.
[This is lighting instruction data for displaying 3, 19 to 23 by lighting. By inputting the lighting instruction data DI+D4 and the clock signal, each of the indicators 15 to 22 lights up, and the input data D1. It displays words, figures, etc. in accordance with D4.

Further, 25 is a disconnection detection section of the display device provided according to the present invention, 26.27 is a transistor whose base input is the output of the drive 5.6 via a resistor 28.29, and 30.31 is the transistor. Resistors 32 and 33 are A N D circuits inserted into the collectors of transistors 26 and 27, and the collector outputs of transistors 26 and 27 and data selectors 3. The output of A and the clock signal T are input. Ro4. 5 is a flip-flop which uses the output of the AND circuit as a set signal. Its output is 0.
．． 02 is a failure calibration signal for the display. Note that R is a reset signal.

Next, with respect to the circuit configured as shown in FIG. 1, the operation of the disconnection detection section of the display, excluding the scanning lighting circuit, will be explained according to the time chart of FIG. 2. Immediately, a lighting state instruction is given to indicators 15 to 18, and indicators 15 and 17 are displayed.
is on and the display 16, 18 is instructed to turn off, as will be described below. At this time, the output A of the data selector 5 is synchronized with the clock T and becomes a waveform A of M2[d.

When the display device 15 is normal, a base current is supplied to the transistor 26 through the resistor 28, so that the collector signal B becomes an "L" level as shown in FIG. On the other hand, when the indicator 17 is disconnected, the base current is not supplied to the transistor 26 even if the output signal A of the data selector 5 reaches the rHJ level indicating the lighting instruction state, so the collector potential remains at the rHJ level. It remains as it is. Therefore A
A pulse synchronized with the clock signal T is output to the output C of the ND circuit 320 to set the flip-flop 34, so that the output of the flip-flop 34 is 0. As shown in Figure 2,
H level, which means that a break in the display has been detected. This state continues until the reset signal R of the 7-lip frog 64 is separately applied, and the output O0 is periodically monitored by a program, or the output 0. By directly activating the alarm means, it is possible to automatically detect whether or not the display is disconnected. This works similarly even when the display devices 15, 16, and 18 that are illuminated during scanning are disconnected. In addition, if the display devices 19 to 22 that are scanned and lit by another drive circuit are disconnected, the data selector
Each block is monitored by a disconnection detection circuit including the driver 6, the transistor 27.degree. AND circuit 33, and the flip-flop 35, and the presence or absence of a disconnection in the display is automatically detected.

As is clear from the above embodiments, according to the present invention, '
P5 Disconnections and faults in several indicators can be detected by simply adding a simple circuit.Furthermore, fault detection, which was conventionally done visually, can be automatically and constantly monitored through program control, etc. System downtime due to sacrificial failures is kept to a minimum.

[Brief explanation of the drawing]

The attached figure is a diagram of a display failure detection circuit showing one embodiment of the present invention, and FIG. 2 is a time chart showing its operation step 1. 1... Counter, 2... Decoder, 3.4... Data selector, 5.6... Driver, 7~10, 23°24.28~31... Resistor, 11~14... Transistor, 15-22...Display device, 25...Disconnection detection section, 32.35...AND circuit, 3/1.35...
Clip flop 1 Review Figure 2 0 Procedural amendment (method) Indication of the case Showa 1957 Patent Application No. 184520 - Title of the invention Person who corrects the display lighting circuit equipped with fault detection g function 151Q111 Formula ≦ ~ 1 11 standing ・V
Works: J, I,' /, ,'
, + Old 1 Shigeyo Osamu Minato
人'ji lr 〒100Marunouchi, Chiyo IH-ku, Tokyo-r l'l S No. 1 'i Stock Co., Ltd. 1: f I
1'/, 'shishi l'r+□ノ(inside ・;・1,su・・
435 4221 Contents of the amendment in the cabinet explanation section of the specification subject to the amendment

Claims (1)

[Claims] A plurality of display devices, a timing signal generation circuit for scanning and lighting control of the plurality of display devices, and a drive circuit that is controlled by an output signal of the timing signal generation circuit and scanning and lighting the plurality of display devices. A display lighting circuit comprising: a display failure detection means that compares the input signal of the drive circuit with the presence or absence of a drive current flowing through the display, and uses the comparison output as a failure detection signal for the display. An indicator lighting circuit equipped with a failure detection function.