JPH0980982A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the operation of a device from being disabled or the like and to enable a continuous operation without rewriting data by controlling copying conditions, based on standard value data, when copying condition data read from a nonvolatile memory is abnormal. SOLUTION: The standard value of the data on a control program and the copying conditions is stored in a ROM 72 and the data on the copying conditions required at the time of forming an image is written in the nonvolatile memory (SRAM) 74 to which power is supplied from uninterruptive power supply consisting of a diode 69 and a battery 70. Moreover, a RAM 73 successively stores the control data of a CPU 62 in a working area and a gate array 71 switches the RAM 73 and the nonvolatile memory 74. Then, the CPU 62 judges whether a copying condition data value read out from the nonvolatile memory 74 is in a prescribed range or not and controls the copying conditions, based on the standard value of the data on the copying conditions stored in the ROM 72, when the copying condition data value is abnormal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus,
More specifically, the present invention relates to an image forming apparatus capable of preventing a trouble of being out of control due to an abnormality in control data when forming an image in a copying machine or a printer.

[0002]

2. Description of the Related Art Conventionally, when controlling a copying machine, copying condition data that needs to be adjusted for each machine regarding copying (for example, toner density set according to user's preference, recording paper edge and original paper edge). The register setting timer for register registration etc.) is stored at the time of machine adjustment using a writable non-volatile memory, and at the time of subsequent copying operation, the stored data is read and based on it. There are copiers configured to perform copying operations.

Japanese Patent Laid-Open No. 5-66624 discloses a copying machine which prevents the copying condition data from becoming uncontrollable when the copying condition data becomes unreadable.

In the above publication, when the copying machine is started up, a non-volatile memory storing copying condition data adjusted for each copying machine is read out and initial setting is carried out, and the first setting means. An abnormality detecting means for detecting an abnormality of the means and an area for storing standard copying conditions common to the copying machine in advance are provided in the program memory, and when an abnormality is detected, copying is performed using the standard copying conditions set in the program memory. There is shown a copier comprising a second initial setting means for initializing the machine. (Hereinafter, it is abbreviated as publicly known technology.) According to the publicly known technology, when an abnormality occurs in the first initial setting means, the non-volatile memory is separated and stored in the program memory as standard copying conditions common to copiers. By the setting by the second initial setting means, the copying work can be continued until the service person arrives without stopping the operation of the copying machine.

However, the above-mentioned known technique is for writing data in the non-volatile memory and detecting the abnormality, and is an effective means only in a special case where the data cannot be written in the non-volatile memory. Occurs when the data itself stored in the non-volatile memory is rewritten or the memory is reset due to noise superimposed on the power supply voltage, for example, pulse noise due to discharge of high-voltage static electricity. Abnormal data is completely powerless and has no ability to solve it.

Further, in the above-mentioned known technique, since the non-volatile memory is disconnected when an abnormality occurs in the first initial setting means, the second initial setting means stores it in the program memory. Although the copy condition can be set, at that time, the first setting means is not writable, so the adjustment data corrected or changed based on the standard copy condition is non-volatile again. The adjustment operation cannot be stored in the memory, and the one-time operation is only repeated every startup,
It is not possible to satisfy the function set under the optimum condition based on the adjustment data for each individual machine.

Furthermore, since the above-mentioned known technique is premised on the data rewriting of the non-volatile memory by a service person, it does not have a function of recording the occurrence of an abnormality and is inconvenient for analyzing the cause of the abnormality.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and does not call a serviceman when an abnormality occurs in data stored in a nonvolatile memory. An image forming apparatus that continues to operate is proposed.

Further, according to the present invention, when it is determined that the data stored in the non-volatile memory is abnormal, the standard value data stored in the ROM instead of the data is transferred to the non-volatile memory for control. An object of the present invention is to realize an image forming apparatus controlled to an optimum state by storing data adjusted as a result of control in a non-volatile memory.

Still further, according to the present invention, when an abnormality occurs in the data stored in the non-volatile memory and relating to the copying condition required for image formation, the abnormal data is read out and the cause of the abnormality can be analyzed. The purpose is to realize the device.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to determine whether a non-volatile memory for storing data relating to a copying condition and a data value relating to the copying condition read from the non-volatile memory are within a prescribed range. And a ROM for storing the judgment value data of the copying conditions, and a control means for controlling the copying conditions based on the standard value data stored in the ROM when the judging means judges that there is an abnormality. This can be achieved by each item of the claims such as an image forming apparatus.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic sectional view showing a schematic structure of a color laser printer which is an image forming apparatus according to an embodiment of the present invention. First, based on this figure, an outline of the entire configuration and operation will be described.

In the figure, a color laser printer 1 is shown.
Has a clamshell structure which is vertically divided into an upper body 1B and a lower body 1A and which can be opened and closed with a support shaft 2 orthogonal to the paper feed path 3 as a fulcrum. A plurality of electrophotographic process units facing the paper feed path 3, that is, a process cartridge (drum cleaning unit) 100 including a photosensitive drum, a transfer / conveyance unit 30, and a fixing unit 23.
The above three units are detachably attached to the color laser printer 1.

The process cartridge, the transfer / conveyance unit, and the fixing unit are indispensable units in the machine configuration, and are treated as replaceable consumable parts, and it is checked whether or not these units are mounted as the status at the time of installing the machine. And is stored in the memory as installation data.

The photosensitive drum 10, which is an image carrier having an OPC photosensitive layer coated on its surface, is driven and rotated in one direction (clockwise in the figure) by a drive source (not shown), and PCL
(Pre-electrification lamp) 11 is used to eliminate the electric charge at the time of the previous print, and the charger 120 with a grid uniformly charges the peripheral surface of the drum to prepare for a new print. After this uniform charging, the image exposure means 13 performs image exposure based on the image signal. Image exposure means 13
Is rotationally scanned by a rotary polygon mirror 13A with laser light emitted from a semiconductor laser (not shown).
After passing B, the optical path is bent by the reflection mirror 13C and projected on the peripheral surface of the previously charged photosensitive drum 10 to form a latent image on the surface of the photosensitive drum 10. In the case of a color image, this exposure is performed for each color, and latent image formation is performed multiple times. The latent image for each color is then developed by the developing device for each color.

Around the periphery of the photoconductor drum 10, there are developers composed of a mixture of toner such as yellow (Y), magenta (M), cyan (C) and black (K) and a magnetic carrier. Filled developing devices 14A, 14B, 14
C and 14D are arranged. From the toner hopper of each color of the toner hopper section 40 to the pipes 44, 45, 46, 4
7, the toner is replenished to each developing device in a timely manner. First, the development of the first color is performed by the developing sleeve 14S which has a built-in magnet and rotates while holding the developer. The developer is regulated to a predetermined thickness on the developing sleeve 14S by the layer forming rod and is conveyed to the developing area. An AC bias voltage V _AC and a DC bias voltage V _DC are superimposed and applied between the photosensitive drum 10 and the developing sleeve 14S. Here, assuming that the potential of the exposed portion of the photosensitive drum 10 is V _L and the surface potential of the charged photosensitive layer other than the exposed portion is V _H , the DC bias voltage V
_By setting _{DC such} that | V _H |> | V _DC |> | V _L | holds, the toner that is triggered by the AC bias voltage V _AC to leave the carrier has a higher potential than V _DC. It does not adhere to the V _H portion, but adheres to the exposed portion of potential V _L , which is lower than V _DC , and is visualized and developed.

After the development of the first color is completed in this way, the image forming process of the second color (for example, magenta) is started.
The photoconductor drum 10 is uniformly charged again, and the image exposure means 13
Thus, a latent image is formed by the image data of the second color.
For the third color (cyan) and the fourth color (black), the same image forming process as the second color is sequentially performed, and a total of four colors are developed on the photosensitive drum 10 to form a toner image in which four colors are superposed. To be done.

As the consumable material data, the developer replenishment amount for each color, as the adjustment data, the adjustment value of the output of the semiconductor laser, the correction value of the output by the combination of the sensitivity of the photosensitive drum and the semiconductor laser, each color at the time of each color exposure A pulse width modulation correction value for laser light emission amount correction, a toner density adjustment value for each color, a preset current value of the charger with a grid, a correction value of the charger current with a grid by the photosensitive drum, and the like are stored.

On the other hand, the recording paper P, which is the transfer material fed by the paper feeding mechanism 22 from the paper feeding cassette 21 or the manual feeding port 24, is transferred to the photosensitive drum 10 by the transfer feeding unit 30 in which the transfer belt 30A is stretched. Transfer belt 30A
The toner images, which are fed to the nip portion (transfer area) 30G formed between and, and in which four colors are superimposed on the peripheral surface of the photosensitive drum 10, are collectively transferred to the recording paper P. Here, a high voltage is applied to the shaft 30C of the upstream holding roller 30B of the transfer belt 30A, and the transfer belt 30A is applied to the shaft 30C.
Conductive brush 30D installed at a position facing each other across
Is grounded, and the fed recording paper P is brush 3
0D and the transfer belt 30A, the brush 30D
The transfer belt 30A is charged by the electric charge injected from the recording paper P.
It enters the transfer area while being sucked into. The recording paper P separated from the photoconductor drum 10 is separated from the transfer belt 30A while being neutralized by using the shaft 30F of the holding roller 30E on the downstream side that stretches the transfer belt 30A as a counter electrode. The transfer belt 30A is used for holding the roller 3 on the downstream side during the formation of the multicolor image.
It is separated from the photoconductor drum 10 about the axis 30F of 0E as the center of rotation.

Here, as the adjustment data, registration adjustment data for aligning the recording paper and the toner image in the paper feed mechanism, adjustment data for deviation of the recording paper caused during conveyance and conveyance adjustment, and transfer current fixed output value. , The transfer current adjustment value is stored.

The recording paper P separated from the transfer / conveyance unit 30 has a heater inside at least one roller.
After being conveyed to a fixing unit 23 composed of two fixing rollers, heat and pressure are applied between the two fixing rollers to melt the adhered toner, and the toner is fixed on the recording paper P, and then the conveyance guide. It goes through 25 and goes up, and is carried out of the apparatus.

The toner remaining on the peripheral surface of the photoconductor drum 10 after the transfer is discharged to the cleaning device 16 by the charge eliminator 15, and is then transferred to the cleaning device 16 by the cleaning blade 16a contacting the photoconductor drum 10. The toner is scraped off, is carried out by a screw or the like, and is stored in the waste toner box 17. The photoconductor drum 10 from which the residual toner has been removed by the cleaning device 16 is PCL1.
After the charge is removed by 1, the charger 120 uniformly receives the charge, and the next image forming cycle starts. In addition, the recording paper P
Is not separated from the transfer belt 30A and the photosensitive drum 1
Since the cleaning blade 16a and the electrode wire may be damaged when wound around 0 and entered above the static eliminator 15, a jam sensor 30H for early detecting the wrapping of the recording paper P is mounted near the static eliminator 15. Has been done.

A paper feed cassette 21, a paper feed mechanism 22, a transfer / transport unit 30, a fixing device 23, etc. are mounted on the lower main body 1A, and an image exposure means 13, a developing device 14, a toner hopper 40, etc. are provided on the upper main body 1B. Incorporated and further, the photoconductor drum 10, the PCL 11, the charger 120, the static eliminator 15,
A process cartridge 100 incorporating a cleaning device 16, a waste toner box 17, etc. is detachably provided in the upper body frame of the upper body 1B.

As the adjustment data, an abnormality code indicating the type of fixing abnormality, data regarding detection of a winding jam in which the recording paper winds around the photosensitive drum, data for recovering the conveyance jam, and paper remaining in the machine are used. Data to exclude,
R for smoothing the jagged edges of the image during image recording
Data indicating whether the print controller section is using the ET mode selection function, counter output value data for detecting whether the waste toner box is full, and photoconductor drum data have been input in the process mode. Data or the like indicating that is stored.

FIG. 2 is a block diagram of the laser color printer, and FIG. 3 is a circuit diagram showing the configuration of the control unit of the laser color printer.

The operation of the control unit will be described with reference to FIG.

Each part arranged in the color laser printer 1 is controlled by the controller 61. The control unit 61 is C
A PU 62 and a memory unit 63 that stores a program and work data are provided, and is responsible for control of feeding and conveyance of the recording paper P and control of an electrophotographic process for image formation. The print controller 64 is responsible for setting the operation mode of the printer, processing data and commands from an external device 60 such as a host computer, and assembling an output image. The print controller 64 is provided with a CPU 75 and an operating unit 65, and all data and commands keyed in from the operating unit 65 are transmitted to the control unit 61, and output from the CPU 62, C
Input to the PU 62 is performed via the I / O unit 66, and is related to the operation of each on-board component 67 such as a motor, a clutch, a solenoid, and a sensor.

FIG. 3 shows a control board 68 which constitutes the control section 61.
It is a figure which shows the principal part of the circuit of. CPU6 on the board
2. ROM 72 in which a control program and a standard value of data relating to copying conditions necessary for image formation are stored, RAM 73 in which control data is sequentially stored in a working area regarding the operation of the CPU, diode 69 and battery 70 Non-volatile memory 74 (hereinafter N
VRAM) may be abbreviated). Data relating to copying conditions necessary for image formation is written in the nonvolatile memory. The gate array 71 is an LSI in which a selector for switching between the RAM 73 and the nonvolatile memory 74 and a buffer register are integrated.

An I / O unit 66 is connected to the control board 68, and operates as an interface between each component inside the machine and the CPU 62. Output elements such as a motor, a clutch, and a solenoid are connected to the output port (not shown) of the I / O unit 66, and various sensors are connected to the input port (not shown) of the I / O unit 66. To be done.

Here, the data relating to the copying conditions required for the above-mentioned image formation, that is, the contents and addresses of the data stored in the non-volatile memory as the consumable material data and the adjustment data, the data when the normal operation is performed. Table 1 summarizes the main values of the ranges and the standard values stored in the ROM.

[0031]

[Table 1]

Usually, the standard value of the data relating to the copying conditions is usually the average of the set values or the initial value of 0, but a little special will be explained.

Address 55 The waste toner box full counter increments the count value by 1 every 10 prints after the inductance detection type sensor (not shown) provided outside the waste toner box 17 detects full. It is a counter for issuing an alarm and stopping the machine when the count value reaches 20, that is, 200 prints after full detection, but if this value shows an abnormal value, it is set to 0 and the intermediate value A method of setting 10 (100 prints) can be considered. To prevent the waste toner box from being overly clogged with toner and damaging the machine, it is desirable to set half the data and continue control. In this case, the standard value is 10.

The address 87 black toner hopper replenishment counter is a counter that increments the counter by 1 in 1 second after the black toner hopper detects that there is no toner and issues an alarm after 30 seconds and stops the machine. Since the counter value cannot exceed 30, set 15 as the standard value in that case.

Since the maximum output value of the toner density detection unit for the address 96 black toner density adjustment value is 4600 counts, 2 bytes are required for accommodating the memory. The lower 1 byte and the upper 1 byte are stored separately. The lower byte has a standard value of 00, and the upper byte has a standard value of 23 which is an average of 46.

FIG. 4 is a flow chart showing the execution of the warm-up task (start-up task when the power is turned on) of the control unit of the present invention.

First, each mode when the CPU 62 operates is set (step Q101), and then the output port of the I / O unit is initialized (step Q10).
After 2), the RAM 73 is initialized (step Q103). Next, it is checked whether or not the nonvolatile memory is mounted (step Q104), and if not mounted, the control is stopped. Non-volatile memory 7
If No. 4 is installed, the output buffer of the I / O unit is initialized (step Q105), and the interrupt condition of the timer used for communication between the print controller 64 and the control unit 62 is set (step Q105).
106) is performed. Subsequently, each gate array including the gate array 71 of the control board 68 is initialized (step Q107) and then required for image formation stored in the non-volatile memory 74 mounted on the control board 68. Check whether an error has occurred in the data relating to the copy conditions (step Q10)
Perform 8). When this check ends, the warm-up task ends, and then the initial task that starts the system of this printer is started.

Next, the check of whether or not an abnormality has occurred in the data relating to the copy conditions stored in the non-volatile memory 74 will be described.

FIG. 5 is a flow chart for judging whether or not there is an abnormality in the data stored in the non-volatile memory, and if there is an abnormality, replace it with a standard value.

There are two cases where it is normal for the data value to increase from 0 and take an arbitrary value and the maximum value is less than or equal to a certain value, and for those between a certain lower limit value and an upper limit value to be normal. , There are three cases where only a specific value (random data) indicates normal. The results summarized in each case are shown in Tables 2, 3 and 4.

[0041]

[Table 2]

[0042]

[Table 3]

[0043]

[Table 4]

The data stored in the non-volatile memory is also checked according to the contents of the above three types.

First, the data having the maximum value is started.
Reading data at the corresponding address (step S101)
Starting from, it is checked whether the data contained in the corresponding address exceeds the maximum value (step S102). If it does not exceed, it is determined that there is no abnormality and the reference address is incremented (step S104). If it exceeds the maximum value (step S101), the operation for setting the memory abnormal state is started (step S103).

The memory abnormality setting refers to an operation of transferring the data found to be abnormal to another nonvolatile memory for storage and then clearing the memory and replacing it with the standard value data stored in the ROM.

After the memory abnormal state is set, the reference address is incremented at the step S104 to advance to the next applicable address, and it is checked whether or not the data exceeds the maximum value. This procedure is sequentially repeated until all the addresses are reached (step S105) to check the data, and then it is checked whether the data is between the specified maximum value and the minimum value.

Starting from the reading of the data of the corresponding address (step S106), it is checked whether the data contained in the corresponding address exceeds the maximum value (step S107). If it does not exceed, then it is checked whether the data is below the minimum value (step S108),
If it does not fall below, the reference address is incremented (step S110), assuming that the data is normal. If the maximum value is exceeded here (step S107)
If it is below the minimum value, it is determined that the data is abnormal, and the operation for setting the memory abnormality is started (step S109). The setting operation in the abnormal memory state is performed in step S1 described above.
It is the same as the case of 03. This procedure is sequentially repeated to check the data until all the addresses are reached (step S111), and then it is checked whether the data matches the random data.

Also in this case, it is started from the reading of the data of the corresponding address (step S112), and it is checked whether or not the data read from the non-volatile memory matches the individual random data (step S113). If the data matches the individual random data, it is determined that there is no abnormality in the data, and the operation proceeds to the operation of incrementing the reference address (step S115). If it does not match the random data, it is determined that the data is abnormal, and the memory abnormal setting operation is started (step S114). Whether the data is abnormal or not, after proceeding to the next step S115, the process is continued until all addresses are reached (step S116), and then the process is terminated.

In the above description, the judging means for judging whether or not the data value relating to the copying condition read from the non-volatile memory is within the specified range, and if the judging means judges abnormal, the above-mentioned The case where the control unit 61 also serves as the control unit that controls the copying conditions based on the standard value data stored in the ROM has been described, but the CPU 75 of the print controller 64 may also serve as the determination unit.

The above-described abnormality check of the data value recorded in the non-volatile memory may be automatically executed by a program, or may be manually performed as necessary.

FIG. 6 is a flow chart for reading and changing data in the nonvolatile memory in such a case.

From the operation unit 65 to the print controller 64
An instruction is given to the control unit 62 via. At this time, the procedure is determined between the CPU 75 of the print controller and the CPU 62 of the control unit by the communication protocol, and it is possible to quickly output or take in data based on a small number of commands. When the mode for checking the data abnormality of the non-volatile memory is selected by the operation of the operation unit 65, the control unit enters the state of waiting for the address data (step T101). Next, the control unit judges the address based on the address data specified by the print controller, accesses the memory at that address (step T102), and waits for a data request signal (step T103). The control unit receives the data request from the print controller and then reads the data in the nonvolatile memory (step T10).
4). The control unit transmits the read data to the print controller (step T105). In the print controller 64, the CPU
5 indicates whether there is an abnormality in which the data value exceeds the maximum value, there is an abnormality value that is greater than or equal to the specified maximum value, or an abnormality value that is less than or equal to the specified minimum value, or there is an abnormality value other than a specific random value. It is configured to judge and transmit the result to the control unit 62. There are cases in which there is an abnormal value in the data and the data in the non-volatile memory is cleared, and cases where the standard value written in the ROM is sent and the data value in the non-volatile memory is changed. If the command sent from the print controller is a clear command, this is judged and the data in the memory is cleared (step T106).

If the clear command is not sent, enter the mode for waiting for the change data to be sent (step T107).
stand by. Preparation of change data after receiving the change data transmitted from the print controller (step T10)
8). Here, the abnormal data of the non-volatile memory,
A ROM that stores data and addresses in other areas of the non-volatile memory and stores standard values.
Address is accessed to enter the state of waiting for a data change execution command (step T109).

When the execution command is received from the print controller, the value of the nonvolatile memory is changed (step T110). That is, the data in the nonvolatile memory is rewritten with the standard value read from the ROM. At this time, an alarm is generated (step T111) to notify the operator that the data in the non-volatile memory has been rewritten.

With respect to the abnormal data generated as described above, the address and the data value itself are stored in another area of the non-volatile memory, and the abnormal data can be easily investigated and analyzed. Further, since it is possible to accurately know the occurrence state of the abnormality when the service person adjusts, it is possible to perform the adjustment with high accuracy.

FIG. 7 is a flow chart from reception of a print command to task execution in the print process of the present invention.

When the start button of the operation unit is pressed or a start signal is sent from an external device, the print start task (step R101) starts, and the rotation of the main motor rotates the photosensitive drum and drives the polygon motor. The detection of the paper size by the cassette, the application of voltage to the charger, and the lighting of PCL are executed.

In the next sequence start task (step R102), the interruption permission is set by the index encoder (not shown) directly connected to the drum, and the distinction between four color image formation and one color monocolor image formation is set. .

In the interrupt by the index encoder (step R103), interrupt control is performed every time an encoder pulse generated in synchronization with the rotation of the drum is generated. For example, individual control such as writing control to the drum by a laser is performed. Is controlled by the hardware configuration unit of the.

Image start task (step R104)
Drives a developing device for each color and applies a developing bias voltage. 1 by the image end task (step R105)
When the color image formation is completed, the driving of the developing device and the application of the bias voltage are stopped. In the case of four colors, yellow, cyan, magenta, and black color images are formed.

Next check task (step R106)
Then, it is checked whether there is an abnormality check, continuous print or single print, and in the case of continuous print, step R102.
Return to and repeat the same process for the second sheet. When the printing operation is completed, the print end task (step R107) stops the main motor, stops the polygon motor, stops the high voltage power source for the charger, etc. Step R1
Stop power supply to all loads started in 01.

FIG. 8 is a flow chart showing the control after it is judged that there is abnormal data and changed to standard value data.

When the power is turned on, the CPU starts up, and in the warming up task, it is checked whether or not the data in the non-volatile memory is abnormal (step U101).
If the data value is abnormal, the standard value stored in the ROM is rewritten (step U102).
After that, control is performed based on this standard value. After executing a series of sequences by a plurality of tasks (one print task) for executing printing (step U103), it is checked whether or not there is a change in the data relating to the copy condition resulting from the control (step U104). If so, the data in the nonvolatile memory is rewritten to the current value (step U105) and saved. After the print end task (step U106), the process ends. As described above, the warm-up task for checking whether or not there is an abnormality in the data in the non-volatile memory is the power ON.
In addition to being executed when the case is opened, it is executed when the case is opened and closed, and when a jam recovery is a recovery work when a jam occurs.

Writing of the copy condition data to the non-volatile memory is performed every time a print is made.
The data relating to the copying condition rewritten into the standard value data stored in M is once used as the control condition and the data value is changed, and is rewritten as the latest data and stored. Therefore, shut down the printer once,
When the power is turned on again, it is treated the same as the data that has not been rewritten due to the abnormality of the nonvolatile memory, and no inconvenience occurs.

The nonvolatile memory of the present invention can freely write and read data, and the written data has a function of retaining the data even when the power of the machine body is turned off. Memory, eg battery-backed static RAM, EEPROM
Plays this role. The ROM in the present invention means a memory that can only read data, that is, a memory that stores data that is prohibited to be rewritten, such as a control program and character data.

Further, the control means in the present invention can include not only the control section that controls the image forming apparatus but also a print controller that shares the control of the image assembling and the operation section.

[0068]

Since the present invention is constructed as described above, it has the following effects.

As an effect of the first aspect of the invention, when an abnormality occurs in the value of the data stored in the non-volatile memory and relating to the copy condition necessary for image formation, the RO
Since the control operation can be continued based on the standard value data stored in M, the inoperability of the image forming apparatus and the abnormal operation of the image forming apparatus based on the abnormal data are prevented, and the data by the service person is prevented. It is possible to continue the operation without rewriting.

As an effect of the invention of claim 2, in addition to the effect of claim 1, when an abnormality occurs in the value of the data relating to the copying conditions required for image formation stored in the non-volatile memory, Since the data relating to the copy condition of the nonvolatile memory is rewritten and controlled based on the standard value data stored in the ROM, a special program for abnormal measures and a special circuit configuration are not required and can be easily realized. .

As an effect of the invention of claim 3, in addition to the effect of claim 2, control is performed by rewriting the data in which the abnormality relating to the copy condition of the nonvolatile memory is generated based on the standard value data stored in the ROM. However, since the data after control is updated and stored in the nonvolatile memory as the latest data, it is possible to perform control while maintaining the continuity of the subsequent image formation.

As an effect of the invention of claim 4, in addition to the effects of claim 1 to claim 3, the standard value data stored in the ROM is rewritten with respect to the data stored in the non-volatile memory. Since the operator is warned that there has been such a case, only the first sheet after rewriting is informed that the control by the standard value data will be performed.

As an effect of the invention of claim 5, in addition to the effects of claims 1 to 4, the address and the value of the abnormal data generated in the nonvolatile memory are stored in another area of the nonvolatile memory. Since the information is stored and can be referred to later, the cause of failure can be easily analyzed during self-diagnosis or regular diagnosis by a service person.

As an effect of the sixth aspect of the present invention, the data relating to the copying conditions required for the image formation includes the adjustment data for maintaining the continuity of each sheet and the consumable material data for affecting the operation in the near future. Therefore, stable control of the image forming apparatus can be realized for a relatively long period of time.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an embodiment of the present invention.

FIG. 2 is a block diagram of an embodiment of the present invention.

FIG. 3 is a diagram showing essential points of a circuit portion of the control board according to the embodiment of the present invention.

FIG. 4 is a flowchart showing execution of a startup task by turning on the power of the control unit of the present invention.

FIG. 5 is a flowchart for determining whether or not there is an abnormality in the data stored in the nonvolatile memory, and if there is an abnormality, replacing it with a standard value.

FIG. 6 is a flowchart for reading and changing data in a nonvolatile memory.

FIG. 7 is a flowchart from reception of a print command to task execution in the print process of the present invention.

FIG. 8 is a flowchart showing control after abnormal data is changed to standard value data.

[Explanation of symbols]

 1 Color Laser Printer 23 Fixing Unit 30 Transfer Conveying Unit 61 Control Unit 62,75 CPU 72 ROM

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Taki Konica Co., Ltd. 2970 Ishikawacho, Hachioji City, Tokyo

Claims (6)

[Claims] 1. A non-volatile memory for storing data relating to a copying condition, a judging means for judging whether or not a data value relating to the copying condition read from the non-volatile memory is within a prescribed range, and a copying condition. If the ROM for storing the judgment value data and the judging means judges that there is an abnormality, the R
An image forming apparatus comprising: a control unit that controls copying conditions based on standard value data stored in the OM. 2. The standard value data stored in the ROM is transferred to the non-volatile memory for rewriting and stored therein, and the control means is based on the standard value data transferred to and stored in the non-volatile memory. The image forming apparatus according to claim 1, wherein the copying condition is controlled. 3. The standard value data transferred to and stored in the nonvolatile memory when the determining unit determines that the data relating to the copy condition stored in the nonvolatile memory is abnormal by the determining unit. The image forming apparatus according to claim 2, wherein the controlled data is stored in the nonvolatile memory after being controlled based on the above. 4. The control unit issues an alarm when the control unit transfers the standard value data stored in the ROM to the non-volatile memory, and the control unit issues an alarm. The image forming apparatus according to item 3. 5. The control unit, when it is determined that the data relating to the copy condition stored in the non-volatile memory is abnormal, sets the address at which the abnormal data has occurred and its value to another value in the non-volatile memory. The image forming apparatus according to any one of claims 1 to 4, wherein the image forming apparatus is configured to be stored in an area and can be referred to later. 6. The image forming apparatus according to claim 1, wherein the data relating to the copy condition is adjustment data and consumable material data.