JPS5991508A - Detection for abnormality of copying machine - Google Patents

Abstract

PURPOSE:To prevent malfunctions, by storing data for check in a prescribed storage area of a non-volatile memory and monitoring this data successively thereafter and stopping the operation of a copying machine when a change of data for check is detected. CONSTITUTION:It is discriminated whether a prescribed time elapses after power-on or not, and if it does not elapse, data for check are read out from a non-volatile memory 3, and these read-out data for check are compared with data for check stored preliminarily in an ROM12, namely, original data of data stored in the non-volatile memory 3 to discriminate whether data for check are changed or not. If they are changed as the result of discrimination, it is judged that the operation of a CPU11 is abnormal, and it is considered that some data is written in a storage area, which is not used by routines other than an abnormality processing routine normally, of the non-volatile memory 3, and the abnormality is displayed on a display device of a copying machine main body 2 and the operation of the copying machine is stopped.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a method for detecting an abnormality in a copying machine.

[Prior art]

In recent years, many copying machines have come to use microprocessor controllers.

Normally, a copying machine needs to maintain maintenance data including copy count data, self-diagnosis data, jam/abnormality detection data, etc., while the copying machine is being used by the same user.

Conventionally, the copying machine described above stores such maintenance data in a non-volatile memory (for example, NOVRAM or battery-backed C-MO8 type RAM), and the contents of this non-volatile memory are stored in case of sudden changes in the power supply or external Appropriate circuits were added to prevent damage from noise and other causes.

However, even if such preventive measures are taken, data errors in the above-mentioned non-volatile memory may occur due to malfunction of the microprocessor due to momentary power interruption, etc., or failure of the IC on the CPU board containing the microprocessor. When a write occurs, the contents of this memory are destroyed, which often causes the problem that the copying machine malfunctions.

〔the purpose〕

SUMMARY OF THE INVENTION It is an object of the present invention to provide a copying machine abnormality detection method that solves these problems and prevents copying machine malfunctions by detecting miswrites to nonvolatile memory.

〔composition〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a control device 1 for a copying machine according to an embodiment of the present invention. A ROM (read-only) that stores control programs and abnormality detection programs (described later), etc.
Memory) 12, RAM (Random Access Memory) which forms the data storage section and work area of the CPU 11
13 and 110 (input/output unit) 14 that interfaces the copying machine main body 2 and the CPU 11. Furthermore, a nonvolatile memory 3 for storing maintenance data is connected to the CPU 11.

FIG. 2 shows an example of how the nonvolatile memory 3 and the CPU 11 are connected. In the figure, a CPU port 1a on which the control device 1 is mounted is provided with a connector 1b, and this connector 1b is connected to an input/output terminal 3b of a nonvolatile memory box 3a containing a nonvolatile memory 3. They fit together, thereby establishing a connection between the CPU 11 and the nonvolatile memory 3.

In addition to the nonvolatile memory 3, the nonvolatile memory box 3a accommodates components forming a peripheral circuit necessary for this memory, and in particular, the nonvolatile memory 3 is a C-MOS type RA
If it is M, it also accommodates a backup power source. Further, this figure only shows the outline of the external appearance of the CPU port 1a and the nonvolatile memory box 3a.

FIG. 3 is a memory map illustrating the storage contents of the nonvolatile memory 3. In this way, the non-volatile memory 3 stores a copy number counter, which is data indicating the number of copies.
Furthermore, storage areas are set for storing diagnosis 1'ffI data, which is data unique to the copying machine, and jam/abnormality detection data, which is data that indicates the content of jams and abnormalities. Check data Di, D2 . ..., a storage area of Dn is set.

In this way, the present invention stores check data DI, D2, ..., Dn in the nonvolatile memory 3, sequentially monitors the contents of these check data, and when the data changes, it is sent to the CPU. 11 miswrites the non-volatile memory 3, that is, the CPU
It is determined that the operation of No. 11 has become abnormal. Also, check data Di, D2 . . . . r Dn is stored in a distributed manner in order to increase the probability of detecting a miss write to the nonvolatile memory 3.

FIG. 4 is a flowchart showing an example of an abnormality detection processing routine executed by the CPU 11. This abnormality detection processing routine is incorporated into the copying machine control processing routine executed by the CPU 11 and is stored in the ROM 12. remembered. In addition, the CPU 11 executes this control processing routine
The time required to execute a cycle is about several m5ec, so the routine for this abnormality detection method also takes several m5ec.
It is executed repeatedly at intervals of about e.

With the above configuration, the probability that the CPU 11 will malfunction depends on the power supply voltage (CPU
The voltage is highest when the voltage supplied to the CPU 11 (supply voltage to the CPU 11) is unstable, and therefore the CPU 11 is likely to operate abnormally, especially when the power supply is momentarily cut off.

Therefore, in this embodiment, a predetermined period of time (Eq.
The processing mode is slightly changed between before and after the lapse of time.

That is, if the result of the judgment 41 that determines that a predetermined time has elapsed since the power was turned on is No, each check data D 1 , D 2 ,
-, Dn is read out (45), and the read check data DI, D2. ....

Dn is compared with the check data stored in the ROM 12 in advance, that is, the data DI, D2, . (1'146).

If the result of Yl disconnection 46 is YES, CPU 11
The operation of the non-volatile memory 3 becomes abnormal, and the abnormality is detected in the non-volatile memory. The contents of sexual memory 3 are destroyed.
I am sorry that it has become abnormal.

Therefore, in this case, process 47 is executed to
)''' is displayed on the display and the copying machine is stopped, after which the process moves to the next routine.

``If the result of 46 is NO, the CPU 11
Since Ogawa is in the royal palace, Ogawa can move on to the next routine without performing any abnormal abductions.

CP after a predetermined time has elapsed since the 1d source was turned on.
When executing the ``U starts detecting this abnormality'' routine,
4'4J If the result of disconnection 41 is YES, execute judgment 42 to check whether the content of the "write completion flag" set by CPU 1 in RAM 13 is 1''.This judgment If the result of step 42 is NO, after all the contents of RAM i 3 have been cleared, it is the diameter that has passed for a predetermined period of time since the power was turned on, and the CPU 11 executes the process 43 to save it from ROM 12. The read check data is quickly written to the corresponding storage area of the non-volatile memory 3, and the process 44 is executed to input "1" to the "write completion flag".Then, the process is repeated as described above. Process 45 and subsequent steps are executed in the same manner.

Then, when the abnormality detection processing routine with K is executed after one control cycle has elapsed immediately after a predetermined period of time has elapsed since the power was turned on, the result of judgment 41 is YES and the result of judgment 42 is YES. , CPU 11
! The process then moves to process 45 and executes the subsequent processes. Note that this abnormality detection process routine (is performed when the check data Di, D2, . . . It is necessary to assume that they are stored in each storage area, and therefore, for example, C
Non-volatile on PU board 1a ((, lH memory l) yl-”
At the time when the box 3a is connected, that is, at the time when the camera is shipped as a product (or before that), the ROM 1
．． It is necessary to store the same data as the check data in a predetermined storage area of the non-volatile memory 3 (in each of the two storage areas).

This may be executed by the CPU 11 during the shipping test, or may be stored in the non-volatile memory 3 in advance.

〔effect〕

As explained above, according to the present invention, it is possible to detect a miswrite in a non-volatile memory, and when a miswrite is detected, the operation of the copying machine is stopped. have

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a copying machine according to an embodiment of the present invention. FIG. FIG. 3 is a perspective view illustrating the U1 mode, FIG. 3 is a memory map of a nonvolatile memory, and FIG. 4 is a flowchart showing an example of abnormality detection processing. ■...!lii control device, 3...・Non-volatile memory, 1
1...CPU, 12-ROM, 13----
RA+M. ε157Figure 2a Figure 3Figure 4

Claims (1)

[Claims] In a method for detecting an abnormality in a copying machine in which maintenance data is stored in a non-volatile memory, check data is stored in a predetermined storage area of the non-volatile memory, and thereafter this check data is sequentially monitored, and this check and reuse is performed. A method for detecting an abnormality in a copying machine, characterized in that when a change in data is detected, this is determined as an abnormality in a control device of the copying machine, and the operation of the copying machine is stopped and the abnormality is displayed.