KR950006578B1 - Circuit for seif-diagnosing troubles of electric light sign apparatus - Google Patents

Abstract

The circuit for diagnosing the fault of the display by itself with microprocessor control includes a detector (11) detecting the power current, a level converter (12) compensating and amplifying the detected signal from minimum to maximum input region of an A/D converter (13) according to the switch on/off state of the display, a diagnosis controller (14) performing the diagnosis process and communicating the instructions with a main controller (2), and a data selector (15) selecting the driving channel of the display by instruction of the controller on whether to display the test pattern or normal information.

Description

Fault self-diagnosis circuit in all-optical display device

1 is a block diagram of a failure diagnosis circuit according to the present invention.

FIG. 2 is a detailed circuit diagram showing an embodiment of the level converter of FIG.

3 is a detailed circuit diagram showing an embodiment of the A / D conversion section and the diagnostic control section in FIG.

* Explanation of symbols for main parts of the drawings

1: Fault diagnosis circuit 2: Main display controller

3: Character display device power supply 4: All-optical display value

11: current detector 12: level converter

12A: Operational Amplifier 13: A / D Converter

13A: A / D Converter 13B: Synchronous Clock Generator

13C: Reference Voltage Generator 13D: 3 Status Buffer

13E: ORGATE 14: Diagnostic control unit

14A: Microcomputer 14B: Parallel Input / Output Device (PIO)

14C: Serial I / O Device 15: Data Selector

The present invention relates to a self-diagnosis circuit for faults in an all-optical display device, and more particularly, to make it easy to determine whether the display device is malfunctioning or fixed.

In general, a conventional all-optical display device composed of a matrix is provided with only a display function, and thus there is no self-diagnosis function when a malfunction occurs due to a failure of a drive or a display device. It is not possible to leave the fault condition for a long time, which reduces the reliability of accurate information transmission, and can damage the aesthetics of the screen with an unclear screen due to error display. Also, it is difficult to visually recognize the fault accurately even when troubleshooting. Maintenance was difficult because it was difficult, and there were problems that took a lot of time.

Accordingly, an object of the present invention is to detect a current value flowing to an all-optical display device and compare and judge the failure by the microcomputer control method. It is to provide.

In order to achieve the above object, the present invention provides a current detecting means for detecting the amount of current flowing in the conductive line in the power supply line of the display element, and corrects the signal detected by the current detecting means to be limited from the individual display element to the entire display element range. Level converting means for amplifying, A / D converting means for converting the analog output corrected by the level converting means into a digital signal so that the microcomputer can easily decipher, and decoding the digitally converted signal from the A / D converting means Diagnostic control means for performing fault diagnosis command on the main display controller and calculating and processing the fault check contents, and sending and receiving commands for fault diagnosis from the main display controller, and the test pattern of the control unit for the all-optical display device to perform the fault diagnosis. Display or normal output from the main display controller. And data selection means for selecting whether or not to express the general information.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of the diagnosis circuit 1 itself in the all-optical display device according to the present invention, in which the amount of current flowing in the lead of the power line supplied from the character display device power supply 3 to the all-optical display device 4 is shown. A current detector 11 for detecting and a level converter 12 for correcting and amplifying the signal detected by the current detector 11 in accordance with the lighting state of the display element from the minimum input to the maximum input range of the A / D converter; The A / D converter 13 converts the analog output signal corrected by the level converter 12 into a digital value, and the digital signal converted by the A / D converter 13 to read out the fault diagnosis command. The diagnostic control unit 14 and the all-optical display device 4 which transmit and receive the processing contents and the channel selection information of the various commands from the main display controller 2 for the fault diagnosis while performing the arithmetic processing of the fault check contents are carried out. Expressed or normal And a data selector 15 which selects a drive channel of the all-optical display device by receiving a command from the inspection controller to determine whether or not the general information is displayed.

FIG. 2 is a detailed circuit diagram showing an embodiment of the level converter connected to the current detector of FIG. 1, wherein the current detector 11 is installed on the positive side of the driving power supply line for the display device and flows in proportion to the lighting number of the device. A current detection sensor that outputs a voltage value that is proportional to the current value.When a current flows through the wire according to the law of the right screw using a hall current sensor or a similar sensor that combines a magnetic core and a Hall element. By using the generated magnetic flux, it detects the current from the main circuit such as the main display controller (2), the character display device power supply (3), and the all-optical display device (4) so that the main circuit is not affected. The level converting unit 12 is composed of a non-inverting operational amplifier 12A using an op amp and input bias current for reducing an input error of the voltage value output from the current detecting unit 11. Commercial resistance (R ₃₎ and, all the display elements are controlled to amplify the correction to the input end up to the range of A / D conversion unit 13 in the light-on state possible variable resistor (VR _1), the fixed resistor (R ₄₎ and ground It consists of a resistor R ₁ .

FIG. 3 is a detailed circuit diagram showing an embodiment of the A / D converter 13 and the diagnostic controller 14 of FIG. 1, which converts the analog signal corrected by the level converter 12 into a digital signal and outputs the digital signal. / D converter 13A, a synchronous clock generator 13B for generating a synchronization signal of the A / D converter 13A, and a reference voltage generator for generating a reference voltage of the A / D converter 13A ( 13C), a 3-state bus buffer 13D for CPU bus connection for data transfer to a microcomputer, and an ore gate 13E for address selection and read signal of the microprocessor A / D converter 13 Microcomputer 14A, which is composed of a CPU and a peripheral circuit, receives an error check command and a command for a method from the main display control system, and performs data input / output and control operations to the input / output device accordingly, and a main display. Send information with the controller The serial input and output device (14C), and a diagnosis control unit 14 in parallel with input and output device (14B) that is connected to the data selecting unit transmits a channel selection control signal to be configured.

The operation and effects of the present invention configured as described above will be described in detail with reference to FIGS. 1 to 3.

First, the basic principle of the error detection method through the current detection unit 11 is to attach a current detection sensor to a positive power line supplied to the all-optical display device 4 to use the voltage value induced by the magnetic flux generated according to the amount of current flowing through the wire. As a result, the voltage induced by the current detector 11 is varied so that the level converter 12 becomes the maximum range of the analog input terminal of the A / D converter according to the current value when all the display elements of the all-optical display device 4 are turned on. Adjusting and inputting the resistor VR ₁ to convert the binary output value, which is the digital output of the A / D conversion section 13, into a decimal number so that the value of the A / D converter 13A is digitally matched. The least significant bit (LSB) of the output corresponds to the lighting of one element.

For example, when an 8-bit resolution A / D converter is used, it is possible to check the lighting of 2 ⁸ = 256 display elements, and it is easy to utilize the design by matching the resolution of the converter with the number of display elements.

As shown in FIG. 1, the microcomputer 14A recognizes and executes the self-diagnosis operation of the fault self-diagnosis operation according to the present invention having the above conditions. The signal input selection (15) is made to select the output terminal of the diagnostic control unit 14, and is transmitted to the drive of the all-optical display device 4 according to the test method instructed to light a predetermined element.

At this time, a current flowing through the driving power supply line for the display element is detected by the current detector 11 as a voltage value and input to the level converter 12.

The level converter 12 amplifies and outputs the output voltage Vout = (1 + R ₂ / R ₁ ) Vin through an operational amplifier 12A (amplification degree A = 1 + R ₂ / R ₁ ) and outputs the above-mentioned operation. Fine-adjust the fixed resistor (R ₁ , R ₄ ) and variable resistor (VR ₁ ) values connected to the inverting input terminal (-) of the amplifier 12A. Use (VR ₁ ) to adjust and amplify to the maximum range of analog input of A / D converter.

The analog signal corrected by the level converting unit 12 as described above is input to the A / D converter 13A of the A / D converting unit 13 as shown in FIG. 3 and supplied to the synchronous clock generator 13B which generates the converting synchronization. The A / D converter 13A is operated to convert the digital signal to the digital signal by the reference voltage of the predetermined level in the reference voltage generator 13C, and the conversion output of the diagnostic control unit 14 is passed through the three-state buffer 13D. It is input to the microcomputer 14A. Accordingly, the microprocessor reads the digit and converts it into a decimal number, calculates the number of lighting elements, compares the value with the number of devices to be lit, diagnoses the failure, and transmits the result to the main display controller 2.

In addition, when the inspection is performed while the display panel is running, the test pattern data transmission is omitted, and the data input of the data selector 5 selects the output of the main display controller 2 as an input and transmits it to the all-optical display device 4. , The check operation is performed by comparing the signal detected by the current detector 11 with the digital data value converted by the A / D converter 13 and the number of lighting elements provided by the main display controller 2. Send to the controller.

As described above, when the detailed operation state of the diagnostic control unit 14 which controls various signals and performs a function according to the present invention, first, the microcomputer 14A is connected to the main display controller 2 through the serial input / output device 14C. When the error check command and the command for the method are received from the controller, the channel selection control signal of the data selector 15 is transmitted through the parallel input / output device 14B. To select and output the test pattern data channel (A) of the microcomputer, and output the test pattern data by the check method instructed by the main display controller (2) to the drive of the all-optical display device (4). Turn on the display element. Subsequently, when the display device is turned on, current flows through the power supply line, and the measured value adjusted through the current detector 11 and the level converter 12 is input to the analog input terminal Vin of the A / D converter 13A.

Accordingly, the microcomputer 14A first addresses the A / D converter 13A to write the data in order to A / D convert the inputted measurement value. And recording signal Detecting the moment of simultaneous logic low, the A / D converter 13A starts converting the input analog signal into a digital signal, and when the conversion is completed, latches the output data therein and then converts the completion signal. Outputs low to inform the microcomputer 14A.

At this time, the microcomputer addresses the A / D converter 13A again and reads out the data. And detoxification A time pulse occurs when the signals are simultaneously low, and at this time, the logic (or) gate 13E goes low, and the A / D converter 13A outputs the data latched therein and simultaneously through the orgate 13E. Since the 3-state bus buffer 13D output is enabled, data is output to the CPU bus and the CPU of the microcomputer 14A can easily read the measurement data.

The binary value read in this way can be converted to a decimal number to calculate the number of lighting elements and compare with the number of display elements to be lit to determine whether it is malfunctioning. After the completion of the measurement, the measurement result is synthesized and transmitted to the main display controller according to the predetermined format, and the channel selection control signal of the data selection unit 15 is completed. Is set to high to return to the normal output data channel (B).

Since the check method instructed by the main display controller 2 above indicates that the display device failure state of the all-optical display device is usually turned off and is still on, the test pattern causes the display element to light up. It is appropriate to take the method of checking whether the device is turned on or off when it is lit and when it is turned on.In case of each device or block by block, it is checked by block. By checking, it is possible to recognize the exact position by the XY coordinates.

For example, when the light is off, the display panel display element should be “0” amperes, but if the current amount is detected, it means that there is a display element that is not off. The number of defective elements is calculated according to the current amount. It is possible to obtain accurate information on the failure status and the details of the failure.

In this way, when the test is completed, the diagnostic control unit 14 can determine the test data by sending the final result to the main display controller according to the data transmission form by arranging the contents of the inspection area, the coordinates of the trouble spot, the number of trouble spots, and the like. It becomes possible.

As described above, the present invention can precisely search for a fault part by instructing a simple command, and clearly distinguish and even detect a fault condition (lighting off and lighting failure), and install an existing circuit without changing a circuit on an already completed display panel. It is possible to diagnose the problem, so the installation cost is low and maintenance time is saved.

Claims (5)

A fault diagnosis circuit of an all-optical display device composed of a matrix, comprising: current detecting means for detecting an amount of current flowing in a conductive line in a power supply line of a pre-installed display element, so that the detection signal can be defined from an individual display element to the entire display element range; A level converting means for correcting and amplifying, an A / D converting means for converting the corrected amplified analog signal into a digital signal and transmitting it to a CPU bus for easy decoding by a microcomputer, and a fault diagnosis instruction from an existing main display controller. A diagnostic control means which accepts the method and controls the A / D conversion means and the data selection means to decode and process the digitally detected detection signal to perform a fault diagnosis function, and to perform a fault diagnosis function. Whether to display the test pattern of the diagnostic control means or display control line Upon failure of the all-optical display device characterized in that it comprises a data selection means for selecting whether or not to express the normal information transmitted from the control system, self-diagnostic circuit. 2. The control circuit according to claim 1, wherein the level converting means adjusts the input bias current compensation resistor (R ₃ ) to reduce the input error and amplifies by correcting to the maximum range of the input terminal of the A / D converter while the entire display device is turned on. A self-diagnosis circuit for faults in an all-optical display device, comprising a variable resistor (VR ₁ ) and a resistor (R ₁ ) (R ₄ ), and a non-inverting operational amplifier (12A) using an op amp. The A / D converter (13A) according to claim 1, wherein the A / D conversion means (130) converts the level-corrected and corrected analog detection signal into a digital signal, and a synchronous clock generator for generating a synchronization signal according to the A / D conversion. 13B, a reference voltage generator 13C for generating a reference voltage according to A / D change, a three-state buffer 13D for transferring digital conversion data to the CPU of the microcomputer, an address selection of the microprocessor, And a logic gate (13E) for detecting the readout signal and operating the tri-state buffer. The microcomputer 14A according to claim 1, wherein the diagnostic control means receives an error check command and a command for a method from a main display controller and performs a data input / output and an A / D converter control operation to the input / output device accordingly. And a serial input / output device (14C) for transmitting and receiving information to and from the main display controller, and a parallel input / output device (14B) for transmitting a channel selection control signal connected to the data selection unit. Fault self-diagnosis circuit. The method of claim 1, wherein the current detecting means is configured to detect a current in an insulated state from the main display controller, the character display device power supply, and the all-optical display device by inducing a voltage to the magnetic flux generated around the conducting wire. Fault self-diagnosis circuit in an all-optical display device.