JPS644195B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a display device for text, etc., and more particularly to a text display device equipped with a function for detecting abnormalities in display commands for text, etc.

Prior Art A text display device includes, for example, an operation control unit (microcomputer) that controls the operation of a copying machine, a text display control unit that outputs a display signal according to a control signal of the operation control unit, and a text display control unit that outputs a display signal according to a control signal of the operation control unit. For example, when the amount of toner in a copying machine is insufficient, the operation control section outputs a control signal corresponding to the insufficient amount of toner to the text display control section. A display signal corresponding to insufficient toner amount is output. When the display signal is output, the message "Please add toner" is displayed on the text display. In addition, this text display device inspects for an abnormality in the control signal that occurs when noise enters the operation control unit or the signal transfer system between the control unit and the text display control unit, and displays an abnormality display on the display unit. It also has a function to make it work.

However, in a text display device equipped with such an abnormality detection function, when an abnormality is detected, the text display device is immediately locked into an abnormal state. That is, the display section was maintained in an abnormal display state, and the text display function was not restored unless the operator turned off the power switch and then turned on the power switch again. Therefore, the copying operation is often interrupted even when an abnormality due to the above-mentioned noise occurs, resulting in a decrease in the efficiency of the operation.

Purpose of the Invention The purpose of the present invention is to continue the abnormality inspection and detect the abnormality without fixing the text display function to the abnormal state in response to the abnormality of the control signal caused by noise contamination in the transfer system as described above. To provide a text display device capable of automatically restoring a text display function after it disappears.

Structure of the Invention The display device for text, etc. of the present invention is provided with a means for counting the number of times an abnormality is detected in a display command for text, etc. The present invention is characterized in that it has a function of displaying an abnormality, continuing the abnormality test for the text display command, and automatically returning the display section to the normal state when normality is restored.

Prior Art The text display device according to the present invention will be described in detail below.

FIG. 1 shows an embodiment of the present invention, in which a text display device includes a microcomputer 3 that inputs signals from various sensors and an operation panel 2 of a copying machine 1 to control various parts of the copying machine, and a microcomputer 3 that inputs signals from various sensors and an operation panel 2 of a copying machine 1. A text display control unit 4 that outputs a display signal according to the input signal, and a display unit 5 (the display panel 6 is shown in the operation panel 2) that displays the text according to the display signal when the display signal is input. have). The text display control unit 4 includes a CPU (signal processing unit) 7 that performs arithmetic processing on input signals;
Sequence for reading the signal from the microcomputer 3 (status signal indicating the status of the copying machine 1), inspecting the transferred signal, and determining the text to be output according to the display command if there is no abnormality in the inspection results, and managing the output time of the text. ROM8 in which programs for such operations are stored,
A text ROM 9 stores character code strings of a plurality of predetermined different display texts, a RAM 12 stores character code strings read from the text ROM 9 in response to display commands, and a It has a character generator 10 that generates a character pattern (11 is an input/output port). The display unit 5 has a display panel 6 made of a liquid crystal display device or a fluorescent discharge tube, and the display timing is controlled by a timing signal from a timing counter circuit 13, and a drive signal according to a pattern signal from a character generator 10. and an X-driver 15 that is driven by the drive signal and outputs a lighting signal that lights up the display panel 6 in dots according to the character pattern.
, a decoder 16 that develops a timing signal and outputs a drive signal corresponding to dynamic lighting, and a Y-driver 17 that is driven by the drive signal and dynamically displays a character pattern based on the lighting signal.

Furthermore, as will be described later, the text display control section 4 in FIG. An error counter 19 is provided that counts the number of times an abnormality is detected when the abnormality is detected. Further, a periodic signal for transfer is inputted to the CPU 7, and this CPU 7 has a function of detecting an abnormality in the transfer data sent in the transfer system and also detecting an abnormality in the synchronization signal for transfer. Furthermore, as described later, the CPU continues to check the normality of the transfer system even after detecting an abnormality in the transfer system and displaying the error message on the display. An automatic normal return function is also provided to ensure normal display.

Based on the above configuration, text display operations will first be explained.

For example, when the user temperature of the fixing section of a copying machine reaches a predetermined value, the microcomputer 3 to which the temperature signal has been input outputs a control signal corresponding to "Copy ready". The control signal is a 30-byte signal as shown in Figures 2 and 3a, the 1st byte is the start code 'AA', the 30th byte is the stop code '55', and the 29th byte is the 1st byte. It is a check sum that represents the sum of information from the byte to the 28th byte. Furthermore, this control signal is a transfer synchronization signal generated by the microcomputer 3, that is, a transfer synchronization signal shown in FIG.
The signal is output for ms and then paused for 50 ms) and is input to the text display control section 4. In the text display control section 4, the control signal is sent to the CPU 7.
(by the program in ROM 8) and determines the corresponding text number. When the address of the text ROM 9 corresponding to the determined text number is designated, the corresponding character code string is transferred to the RAM 12. The character font (font) stored in the ROM 8 is read out using this character code string as part of the address, and while access is controlled by the signal from the timing counter 13,
Written to RAM12. Character generator 10 generates a character pattern based on the contents stored in RAM 12, and this display pattern is read out and taken into shift register 14. When the shift register 8 drives the X-driver 15 and outputs a lighting signal, the Y-driver 17 sequentially scans the display panel 6 using the dynamic lighting control signal and displays, for example, "Copy ready".

The display operation in the text display device described above is started by clearing the transfer data test and synchronization signal test shown in FIGS. 4 and 5. As the transfer data test, the start code test of the first byte is performed. , checksum inspection of the 29th byte and
A 30-byte stop code check is performed.

As shown in FIGS. 4 and 5, when the CPU 7 of the text display control unit 4 receives the periodic signal from the microcomputer 3 (see b and c in FIG. 3), it sets a 1-sec timer and checks the first signal sent. The start code is checked using the incoming data, and at this time, the read data counter (not shown) of the CPU 7 is set to 1. If the start code is not the predetermined code, it is determined that the transfer synchronization signal is not a synchronization signal but a noise or other signal, and the read data counter continues to increment at 1. do not have. That is, it continues to ignore the received data without proceeding until the start code arrives at the first byte.

Only when the start code is received in the first byte, the lst READ Flag is cleared and the read data counter is incremented, and the read data is read from the second byte to the 30th byte every time a synchronization signal is received until the 30th byte is received. Load data up to. When the 30th byte is read, the lst READ Flag is set and
Check whether this 30th byte is a stop code. If the code is specified, the sum of data from the 1st byte to the 28th byte (check
Sum) is calculated and compared with the data indicating the check sum value in the 29th byte. If there is no abnormality, if the previous error occurred, after clearing the error count or synchronization signal error flag, the microcontroller 3 sends a message. A flag indicating that the transferred data was successfully received.
That is, the transfer OK flag is set and the process proceeds to the text output display process described above.

If the 30th byte is not a stop code, perform data error processing (see Figure 5A). In this data error processing operation, each time an abnormality is detected, the error counter 19 is counted up and the read data counter is initialized to 1.
When the error count reaches 10 times or more, that is, when abnormality detection is performed 10 times or more, an error is displayed on the display section 6. If the error count is less than 10, the abnormality test is repeated without displaying an error message on the display. In this way, when an error is displayed and when the error count is less than 10, the value of the read data counter is initialized to 1 in order to receive the first byte. In other words, the abnormality inspection continues even after the error is displayed.

Similar to the stop code test, when an abnormality is found in the checksum verification test, the data error handling operation described above is performed. (However, if an error is detected in the stop code, the checksum check will not be performed.

On the other hand, the synchronization signal test is performed based on the flowchart shown in FIG. 5B. That is, each time a synchronization signal is interrupted from the microcomputer 3, the CPU 7 of the text display control unit 4 sets a 1-sec timer, and when the timer times out, it is determined that there is no synchronization signal for 1 second, and it is displayed as a synchronization signal error. An error is displayed in section 6. In this case, as in the case described above, even if an error is displayed, the value of the read data counter is initialized to 1 in order to receive the first byte, and the abnormality check is continued.

The CPU 7 performs display operations by processing only normal signals from the microcomputer 3 while performing transfer data inspection and synchronization signal inspection in this manner, and when an abnormality is detected, displays an abnormality instead of text display. By initializing the read data counter to 1 to avoid deadlock due to an error display, the synchronization signal and received data from the microcomputer 3 are constantly inspected even when an error is displayed, and the original normal state is restored when the error state is exited. It has an automatic normal return function that starts display operations.

Effects of the Invention Since the signal processing unit (CPU 7) of the text display device of the present invention is provided with the above-mentioned automatic normal recovery function, for example, the copying machine control unit 3
Watchdog timer (in a microcomputer control system, it is used to periodically clear the timer using a real-time clock in order to check that it is operating normally and to determine that an abnormality occurs when it times out. This prevents the text display device from being blocked due to a temporary abnormality in the transfer system that is not detected during normal operation, and enables smooth operation without any hindrance after normal recovery.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the main body and control unit of a copying machine incorporating the text display device of the present invention, FIG. 2 is an explanatory diagram showing an example of data transferred to the text display device of the present invention, and FIG. 3 is a transfer signal, FIGS. 3B and 3C are explanatory diagrams showing transfer synchronization signals for the above-mentioned transfer data, and FIGS. 4 and 5 A and B are flowcharts showing the operating procedure in the text display device of the present invention. It is. 1... Copying machine, 2... Operation panel, 3... Copying machine control section (microcomputer), 4... Text display control section,
5...Text display unit, 6...Display panel, 7...Signal processing unit (CPU), 8...Program ROM,
9...Text ROM, 10...Character generator, 11...I/O port, 12...RAM,
13...Timing counter circuit, 14...Shift register, 15...X-driver, 16...Decoder, 17...Y-driver, 18...Output interface, 19...Error counter.

Claims (1)

[Scope of Claims] 1: an operation control unit 3; a memory 9 that stores predetermined display data; a signal processing unit 7 that reads display data from the memory in accordance with a display command from the operation control unit; 8; and a display unit 6 that displays the read display data; means for detecting an abnormality; (b) means 19 for counting the number of abnormality detections in the display command; (c) when the number of abnormality detections reaches a predetermined value, an abnormality is displayed on the display unit from when the number of abnormality detections reaches a predetermined value. (d) When the number of abnormality detections reaches a predetermined value, the abnormality detection of the display command is continued after that, and when normality is restored, the display unit displays normality. Device. 2. The display device according to claim 1, wherein the display data is a display text.