JPH06333186A - Fault countermeasure circuit - Google Patents

Abstract

PURPOSE:To provide the fault countermeasure circuit by which a fault mode is recognized even without operation of a master circuit when a service man applies again a commercial power supply by warning it to a customer when a fault takes place and even when the service man is called by the customer interrupting power. CONSTITUTION:A port exclusive for a standby lamp 14 is provided to a microcomputer 12 and the lamp is lighted continuously in the normal standby mode and blinked when a fault is detected and the standby mode is set. Furthermore, a nonvolatile memory (E<2>PROM) 18 possible for electric erasure and writing to store the presence of the fault or fault location is provided and even when a commercial power supply is interrupted and applied again, the location of the fault and the display of fault location are reproduced while keeping the standby state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure countermeasure circuit for preventing a secondary failure or danger and promptly performing failure repair when an electronic device fails. In particular, it is an object of the present invention to provide a failure countermeasure circuit suitable for a large circuit scale, a service workability that is poor due to the installation location, and an expensive product.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a conventional example of a failure countermeasure circuit provided in an electronic device such as a video projector. In the figure, reference numeral 1 denotes a main circuit of the video projector, which is a portion to which a voltage is supplied from the switching power supply circuit 2. The main circuit 1 includes circuit parts such as a horizontal deflection circuit 3, a vertical deflection circuit 4 and a high voltage generation circuit 5. The main circuit is composed of various other circuits, but the description thereof is omitted here. 6, 7, 8 are 3, 4, respectively
5 is a fault detection circuit for detecting the fault of No. 5. Some circuit parts whose description is omitted include the failure detection circuit (not shown). Next, 9 is a standby circuit, which is a portion to which a voltage is supplied from the standby power supply circuit 10. The following are included in the standby circuit 9. Reference numeral 11 is an infrared remote control (hereinafter abbreviated as remote control) receiver, 12 is a control circuit including a microcomputer, 13 is an E ² PROM, and 14 is an L integrated with a power-on lamp and a standby lamp of the main circuit.
An ED lamp, 15 is a display unit for displaying a failure location. Further, this video projector is provided with a mains switch 16 for connecting and disconnecting the commercial power source, an outlet plug 17 for connecting to the commercial power source, and the like.

Next, the operation will be described. This video projector is designed to be operated by a remote control. For example, when the control circuit 12 receives a power-off command through the receiving unit 11, the power-on / off control output port becomes “L” and the operation of the switching power supply circuit 2 is stopped. Since the voltage is not supplied to the main circuit 1, the main circuit 1
Stops working. This state in which the main circuit 1 is powered off and the standby circuit 9 is operating is called a standby state. This video projector is LE in standby
D14 lights up in red. When the power-on command is received from the remote controller in the standby state, the power-on / off control output port of the control circuit 12 becomes “H”, the switching power supply 2 is operated, and the main circuit 1 is operated. A state in which the main circuit 1 is operating is called a power-on state. In the power-on state, the LED 14 lights up in green.

Further, this video projector can operate contrast, bright and the like. Operation status such as power on / off, contrast, and brightness setting value is E ² PR
It is stored in the OM 13, and the microcomputer in the control circuit 12 is automatically stored in the E ² PROM 13 even when the power is turned on again after the mains switch 16 is turned off, the outlet plug 17 is pulled out, or a power failure occurs. The information that was read is read and the previous operating state is reproduced.

Next, the failure countermeasure circuit will be described. For example, when the horizontal deflection circuit 3 is stopped, if there is no failure countermeasure circuit, the image is displayed while the horizontal scanning of the CRT (not shown) for projecting the image is stopped.
The electron beam is concentrated on the line, which causes a secondary failure in which so-called burn-in occurs on the phosphor. In this video projector, the failure detection circuits 6 to 8 output "H" in a normal state. When the horizontal deflection circuit 3 is stopped, the failure detection circuit (A) 6 detects the failure and notifies the control circuit 12 of “L” information. When even one input from the failure detection circuit becomes "L", the control circuit 12 enters the standby state, the power-on / off control output port becomes "L", and the LED 14
Lights up in red, and the operation of the switching power supply circuit 2 stops. At this time, the power-off information is written in the E ² PROM 13 as in the standby state by a normal operation. Further, by setting the output port corresponding to the “L” input port to “L”, the “A” portion of the display unit 15 is turned on. Similarly, when the vertical deflection circuit 4 is stopped or the voltage of the high voltage generation circuit 5 becomes abnormally high, the failure detection circuit (B) 7 and the failure detection circuit (C) 8 output "L". The control circuit 12 operates so that the "B" portion and the "C" portion of the display unit 15 are turned on when the standby state is set. In this way, even if a failure occurs, a secondary failure is prevented by shifting to a standby state where the operation of the main circuit is stopped, and the failure location is displayed. Just replace it,
Can be quickly repaired.

[0006]

However, in the conventional failure countermeasure circuit as described above, when a failure occurs, the customer knows the failure by seeing the lighting of the display section, and turns off the mains switch 16 or the outlet plug 17. When the service person is called after turning off the commercial power by some method such as pulling it out, or when the power is turned on again after a power failure, the standby state is entered, but the display unit 15 does not light up. I do not know whether it is in the standby state due to the remote control operation of, or because the failure countermeasure circuit has worked.
Moreover, if it is a failure, there is a problem that it is not possible to know where the failure is. In such a case, the service person needs to turn on the power supply of the defective video projector with the remote control and see that the failure countermeasure circuit works again to turn on the display, preventing the secondary failure of the product, It was not good for safety. In addition, even if only the standby circuit is used when a failure occurs, it is not preferable for safety to let the customer leave the video projector energized.

Further, in the failure countermeasure circuit as described above,
Since an output port to the display unit is required in addition to the input port from the failure detection circuit, many valuable I / O ports of the microcomputer in the control unit are used, so other functions for controlling the video projector are deleted. It was necessary to make such sacrifices.

The present invention has been made to solve the above problems, and when a failure occurs, the customer can be clearly warned of the failure and the customer can turn off the commercial power supply and wait for a serviceman. The purpose is to provide a failure countermeasure circuit that allows the service person to know the failure mode without operating the main circuit when the commercial power is turned on again. Furthermore, the use of the input / output port of the microcomputer The goal is to realize high-performance products by reducing the number and using that amount for other functions.

[0009]

A control circuit for controlling the operation of a main circuit, a failure detection circuit for detecting a failure in the main circuit, a display section for displaying the presence or location of a failure, and the main circuit being stopped. When the failure detection circuit detects a failure, it stops the operation of the main circuit and blinks the standby lamp.
The failure is displayed on the display unit. In addition, a standby lamp that lights red is used.

The failure detection circuit has a control circuit for controlling the operation of the main circuit, a failure detection circuit for detecting a failure in the main circuit, and a display section for displaying the presence or location of the failure. In this case, the operation of the main circuit is stopped and the failure is displayed by blinking the display section.

Further, a control circuit for controlling the operation of the main circuit, a standby lamp that lights up when the main circuit is stopped, a failure detection circuit for detecting a failure in the main circuit, and an electric erasing and writing are possible. Non-volatile memory (hereafter E ² PR
OM), and when the failure detection circuit detects a failure, the operation of the main circuit is stopped, the standby lamp is blinked, and the information on the existence of the failure is written in the E ² PROM, and then the power is turned off. When re-input, E ²
By reading the information from the PROM, the standby lamp is made to blink while the main circuit is stopped.

A failure countermeasure circuit for a main circuit composed of a plurality of circuits, a control circuit for controlling the operation of the main circuit, and a plurality of failure detection circuits for detecting a failure of each circuit in the main circuit. , A display section for displaying a failure or a failure point, and E
^{2 If} PROM is provided and the failure detection circuit detects a failure, the operation of the main circuit is stopped, the location of the failure is displayed on the display, the information on the location of the failure is written to E ² PROM, and then the power is turned off. When re-input, E ² P
By reading the information in the ROM, the presence or the location of the failure is displayed on the display unit while the main circuit is stopped.

Further, in order to reduce the number of input / output ports of the microcomputer, an input / output port is used, and an input port for information from the failure detection circuit and an output port for information to the display section are made common.

[0014]

In the failure countermeasure circuit configured as described above, the standby lamp blinks when a device failure is detected. Therefore, the difference from the normal state (the standby lamp lights continuously without blinking) Customers can see at a glance. A standby lamp that glows in red is used, and when a failure is detected, it will flash in red to notify the user that it is psychologically abnormal. Further, when a device failure is detected, the presence of the failure and the failure location can be displayed at the same location by blinking the display unit.

In addition, the information of the failure point is written in the E ² PROM, and when the power is turned on again, the microcomputer automatically reads the information of the E ² PROM and reproduces the original state. Flashes,
The failure point is displayed on the display. Even if the customer calls the service person after turning off the commercial power source, if the service person turns on the commercial power source again, it can be seen at a glance that the failure state remains in the standby state.

Further, the microcomputer of the control unit is
An input / output port for information from a failure detection circuit and an output port for information to a display section are shared by using an input / output port, thereby providing a failure countermeasure circuit with a small number of valuable input / output ports.

[0017]

【Example】

Example 1. FIG. 1 is a block diagram showing an embodiment of the present invention, in which 1 to 11 and 13 to 17 are the same as those in the conventional example, and 12 is a program of a microcomputer which is changed in comparison with the conventional example, and an A control circuit 18 having some functions added is an E ² PROM for storing failure information or failure location. The LED 14 is configured to light up with a dedicated output of the control circuit 12.

Next, the operation will be described. FIG. 2 shows a flowchart showing the operation of the power supply ON / OFF together with the operation of the failure countermeasure circuit. This video projector is designed to be operated by a remote control. For example, when the control circuit 12 receives a power-off command through the receiving unit 11, the power-on / off control output port becomes “L” and the operation of the switching power supply circuit 2 is stopped. Since the voltage is not supplied to the main circuit 1, the operation of the main circuit 1 is stopped (standby state). In the standby state, the LED 14 lights up in red. When the power-on command is received from the remote controller in the standby state, the power of the control circuit 12 is turned on / off.
The OFF control output port becomes “H”, the switching power supply circuit 2 is operated, and the main circuit 1 is operated (power on state). In the power-on state, the LED 14 lights up in green.

Further, this video projector can operate contrast, bright and the like. Operation status such as power on / off, contrast, and brightness setting value is E ² PR
It is stored in the OM 13, and the microcomputer in the control unit 12 is automatically stored in the E ² PROM 13 even when the power is turned on again after the mains switch 16 is turned off, the outlet plug 17 is removed, or a power failure occurs. The information that has been read is read and the previous operating state is reproduced.

Next, the operation of the failure countermeasure circuit will be described. In this video projector, the failure detection circuits 6 to 8 output "H" in a normal state. For example, when the horizontal deflection circuit 3 is stopped, the failure detection circuit (A) 6 detects the failure and notifies the control circuit 12 of "L" information. In the control circuit 12, when even one input from the failure detection circuit becomes "L", the power supply ON / OFF control output port becomes "L", and the operation of the switching power supply circuit 2 is stopped. At the same time, unlike the standby state by the remote control operation in the normal state, the LED 14 blinks in red and the information of the failure portion is written in the E ² PROM 18. Further, by setting the output port corresponding to the “L” input port to “L”, the “A” portion of the display unit 15 is turned on. Similarly, when the vertical deflection circuit 4 is stopped or the voltage of the high voltage generation circuit 5 becomes abnormally high, the failure detection circuit (B) 7 and the failure detection circuit (C) 8 output “L”, The control circuit 12 operates so that the “B” portion and the “C” portion of the display unit 15 are turned on as well as the standby state. In this way
Even if a failure occurs, a secondary failure is prevented by shifting to a standby state in which the operation of the main circuit stops.
Since the failure point is displayed, the service person can replace the circuit board according to the display, and quick failure repair can be performed as in the conventional case. But LED
It can also be determined whether 14 is lit or blinking.

Next, the mains switch 16 is turned off,
The operation when the commercial power is turned on again after the outlet plug 17 is pulled out or a power failure occurs will be described. FIG. 3 shows a flowchart of the algorithm of the reset operation when the commercial power is turned on again. After initialization of the microcomputer in the control circuit 12, the E ² PROM 13, 1
The information of No. 8 is read out. At this time, when the information of the failure point exists, the failure point is displayed from the display unit 15 with the power off (standby state), and the LED 14 blinks in red. If the information of the failure portion does not exist, the normal standby state or the power-on state is set depending on whether or not the power-off information exists. In this way, even if the customer turns off the commercial power and calls a service person, when the service person turns on the power again, even if the main circuit 1 is not turned on, the failure occurs in the standby state and the failure. Can inform the location.

Example 2. FIG. 4 is a block diagram showing another embodiment according to the present invention. 1 to 11 and 13 to 18 are the same as those in the first embodiment, and 12 is a control circuit in which the program of the microcomputer is changed and the function of the input / output port is partially changed as compared with the conventional example. Here, the control circuit 12 uses an I / O port, and has an input port for information from the failure detection circuit and an output port for information to the display unit in common.

The operation of failure detection and failure location display in this embodiment will be described. Failure detection circuits 6-8 in the normal state
Outputs "H", and the I / O port for fault detection and fault location display is in the input mode when the output is in a high impedance state. For example, when the horizontal deflection circuit 3 stops, the failure detection circuit (A) 6 detects the failure and the control circuit 1
2. Give the information of "L". When the input from the failure detection circuit becomes "L", the control circuit 12 sets the output of the I / O port to which "L" is input to "L". Therefore, the control circuit 12 functions to hold "L" even if the "L" state of the failure detection circuit is momentary. In this way, the display unit 1
The "A" part of 5 lights up. Similarly, when the vertical deflection circuit 4 is stopped or the voltage of the high voltage generation circuit 5 becomes abnormally high, the failure detection circuit (B) 7 and the failure detection circuit (C) 8 output "L". , The output of the corresponding I / O port becomes "L" upon receiving it, and the display unit 1
The control circuit 12 works so that the “B” part and the “C” part of 5 are turned on. The other operation of the failure countermeasure circuit is similar to that of the first embodiment.

In the above-mentioned first and second embodiments, the case where the E ² PROM for storing the defective portion is different from the E ² PROM for storing the operation state of the video projector is shown. Of course, it is not necessary to add an E ² PROM for storing a failure location by using the same function if there is a margin.

Further, in the above-mentioned first and second embodiments, the example in which the standby lamp is made to blink is shown, but the display section for displaying the presence or the location of the failure may be made to blink.

[0026]

Since the present invention is configured as described above, the standby lamp blinks when a device failure is detected, so that the normal state (the standby lamp is
Customers can also see at a glance the difference between continuous lighting without blinking). A standby lamp that glows in red is used, and when a failure is detected, it will flash in red to notify the user that it is psychologically abnormal.

Further, even if the customer calls the service person after turning off the commercial power source, if the service person turns on the commercial power source again, it can be seen at a glance that the failure state remains in the standby state.

Further, the microcomputer of the control unit uses the input / output port as a common input port for the information from the failure detection circuit and the output port for the information to the display unit, so that a valuable input / output port can be provided. It is possible to provide a failure countermeasure circuit with a small number of uses.

[Brief description of drawings]

FIG. 1 is a block diagram showing a failure countermeasure circuit according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the first embodiment.

FIG. 3 is a flowchart showing an operation at the time of reset in the first embodiment.

FIG. 4 is a block diagram showing a failure countermeasure circuit according to a second embodiment of the present invention.

FIG. 5 is a block diagram showing a conventional failure countermeasure circuit.

[Explanation of symbols]

1 Main Circuit 2 Switching Power Supply Circuit 6-8 Failure Detection Circuit 9 Standby Circuit 10 Standby Power Supply Circuit 11 Remote Control Receiver 12 Control Circuit 13 E ² PROM 14 Standby LED Lamp 15 Failure Display 16 Mains Switch 18 E ² PROM

Claims (6)

[Claims] 1. A control circuit for controlling the operation of the main circuit, a failure detection circuit for detecting a failure in the main circuit, a display section for displaying the presence or location of the failure, and the main circuit being stopped. When the failure detection circuit detects a failure, it stops the operation of the main circuit and blinks the standby lamp.
A failure countermeasure circuit characterized in that a failure is displayed on the display unit. 2. The failure countermeasure circuit according to claim 1, wherein the standby lamp lights up in red. 3. A failure detection circuit, comprising: a control circuit for controlling the operation of the main circuit; a failure detection circuit for detecting a failure in the main circuit; and a display section for displaying the presence or location of the failure. When a failure is detected, the failure countermeasure circuit is characterized in that the operation of the main circuit is stopped and the failure is displayed by blinking the display section. 4. A control circuit for controlling the operation of the main circuit, a standby lamp that lights up when the main circuit is stopped, a failure detection circuit for detecting a failure in the main circuit, and an electrical erasing / writing function. Possible non-volatile memory (hereafter E ² P
ROM)), and when the failure detection circuit detects a failure, the operation of the main circuit is stopped, the standby lamp is blinked, and the information on the existence of the failure is provided in the E ² PROM.
A failure countermeasure circuit characterized in that, when the power is turned off and then turned on again, the information in the E ² PROM is read so that the standby lamp blinks when the main circuit is stopped. 5. A failure countermeasure circuit for a main circuit composed of a plurality of circuits, comprising a control circuit for controlling the operation of the main circuit and a plurality of failure detection circuits for detecting a failure for each circuit in the main circuit. And a display section that displays the failure or failure location,
E includes a ² PROM, when failure detection circuit detects the failure to stop the operation of the main circuit, with displaying the failure location in the display unit, writes the information of fault location in E ² PROM, off the subsequent power If it is turned on again, E ² P
A failure countermeasure circuit characterized in that the presence of a failure or the location of a failure is displayed on the display section in a state where the main circuit is stopped by reading the information in the ROM. 6. A control circuit, a failure detection circuit for detecting a failure in the main circuit, and a display section for displaying the presence or location of the failure, wherein the control circuit has an input port from the failure detection circuit. A failure countermeasure circuit characterized in that it also serves as an output port to the display section.