JPH09319265A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assure data in backing up the data in a backup memory by checking whether or not abnormality exists in the data in the backup memory and using a preliminary parameter when the abnormality exists. SOLUTION: A power-source-off detecting means 13 informs the image forming device 2 that various parameters in a RAM are erased because an off-state is detected. A data abnormality detecting means 26 judges whether or not the data written in or read out from a storage means 10 is normal. In the case of write, a write continuing flag is set until the write is finished, and in the case of readout, whether or not the set write continuing flag is still set is checked. In the case the flag is still set, that is, it is recognized as a data error, the parameter (preliminary parameter) in an EPROM in the image forming device is processed to be set as the parameter in the backup memory.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor image forming apparatus for forming a multicolor image by electrophotography.

[0002]

2. Description of the Related Art Conventionally, in a multicolor image forming apparatus for forming a multicolor image by an electrophotographic method in this type of apparatus, a high voltage for applying a transfer bias to a transfer charger and a developing bias to a developing unit according to the number of transfers. A unit is provided. The high-voltage unit is sequentially turned on / off by the printer control unit in accordance with a plurality of recording cycles to form a multicolor image. FIG. 1 shows a printer control mechanism of this type of multicolor image forming apparatus. In FIG.
1 is a printer control circuit. The image forming apparatus 2 generates a video signal (VDo) 3 based on the multicolor image signal from the printer controller 11 and outputs it to the drive circuit 4. The drive circuit 4 is a circuit for driving a semiconductor laser (not shown) and outputs a laser drive signal 5.

The image forming apparatus 2 outputs first and second video signals generated by multicolor image signals to form first and second electrostatic latent images on an image carrier (not shown).
The activation signal 6 is output to the bias control means 7. The storage unit 10 stores various parameters relating to a use environment and a high voltage bias (transfer, development) based on a multicolor image signal from the printer controller 11. The bias control means 7 uses the bias data stored in the storage means 10 to output a corresponding bias signal 8 to develop the electrostatic latent image and transfer the recording paper to form a multicolor image.

The detecting means 25 is, for example, the temperature sensor information 2
3 and the humidity sensor information 24 are notified to the image forming apparatus 2. In the image forming apparatus 2, these information and the storage unit 1
Grasping the current usage environment based on various parameters in 0,
Select the best bias data. Information of the engine at the time of image formation is notified to the printer controller 11 as a status via the video interface 18.

Next, the operation between the printer control circuit 1 and the printer controller 11 will be described with reference to FIGS. 2 and 3. FIG. 2 shows an interface signal line connecting the printer control circuit 1 and the printer controller 11. FIG. 3 shows the timing of the command / status transferred by the interface signal line. The printer control circuit 1 outputs the / PPRDY signal 121 when communication with the printer controller 11 becomes possible after the power is turned on.
To true. Then, after confirming that the / CPRDY signal 123 from the printer controller is true, the process for bringing the image forming apparatus 2 into the printable state is started. And if it becomes printable,
/ RDY signal 122 is set to true.

On the other hand, the printer controller 11 sets the / CPRDY signal 123 to true and the / CBSY signal 123 to true as shown in FIG. 3 when communication becomes possible.
After setting to e, the CMD signal 125 is transmitted in synchronization with the pulse by the CCLK signal 126. Then, after sending the command by the CDM signal 125, the CBSY signal 12
Set 4 to false. The printer control circuit 1 is
When the command is received in the above procedure, the SBSY signal 12
After setting 4 to true, the STS signal 128 is transmitted in synchronization with the pulse by the CCLK signal 126. After sending the status by the STS signal 128, the SBSY signal 127 is set to false. Through the above procedure, the printer control circuit 1 and the printer controller 11 send and receive commands and statuses. The procedure of the next printing operation will be described.

The printer controller 11 confirms that the / RDY signal 122 is true and then outputs / PRN.
The T signal 129 is set to true. On the other hand, the printer control circuit 1 outputs the / PRNT signal 129 as shown in FIG.
When it is recognized that it is true, the pre-rotation operation of the electrophotographic process is started, and after the detection of the REJTOP signal TOP portion (not shown) from the detection means 25, t1 hour later / TO
The pulse of the P signal 130 is output. The printer controller 11 synchronizes with the pulse of the LSYNC signal 133,
The magenta image signal / VDo 132 is output. Similarly, cyan, yellow, and black image signals are output to form a multicolor image. Further, the T for each image signal at this time
The time after detection of the OP part, t1 is a value obtained by converting the mounting deviation value of the sensor for each machine into time, which is a fixed value which is adjusted at the time of shipment and stored in the storage means 10 in FIG.

Next, the conventional printing operation will be sequentially described with reference to the flowchart showing the sequence procedure for forming the image shown in FIG. When the power is turned on, the collection of temperature and humidity data is started to select the optimum conditions according to the operating environment, and the initial settings of various parameters such as the setting of factory adjustment values and the setting of high voltage bias data. Is performed (step S10). The process proceeds to step S11, and a startup process such as checking for the presence or absence of the developing device and starting the temperature adjustment of the fixing heater to the stand-by until the printing operation becomes possible is executed. However,
At this time, if a failure is detected by self-diagnosis, it is judged as a failure. Waiting until the fixing temperature reaches the target temperature such as standby (step S12), and if the standby occurs, various conditions for determining the usage environment from the temperature and humidity data that started the collection and performing optimum printing Parameters are selected (step S13).

This processing is performed every 30 minutes of energization,
As data for determining the usage environment, data for the past 8 hours is stored in the RAM in the image forming apparatus 2. In this state, it is also checked whether or not there is a print instruction (step S14). If there is an instruction, the print sequence of the electrophotographic process is executed (step S14).
15) Output the optimum image. When the printing operation is completed (step S16), the process for returning to the standby operation is performed, and the operation from step S12 is repeated.

[0010]

The conventional image forming apparatus is constructed as described above, and the processing for grasping the usage environment for optimum printing is performed every 30 minutes of energization, and the usage environment is judged. The data for the past 8 hours is stored in the RAM as the data for this purpose. However, when the power is turned off due to the user or a momentary power failure, the data accumulated in the past is erased and the data for judging the usage environment becomes insufficient. For this reason, a method of storing data in the backup memory at regular intervals is conceivable. However, if the write operation is performed every time the data is collected, the number of times of writing in the backup memory is limited, and backup is performed multiple times. The use of the memory causes a problem that the stored data cannot be guaranteed.

Therefore, an object of the present invention is to provide an image forming apparatus capable of guaranteeing data when data is backed up in a backup memory.

[0012]

In order to achieve such an object, the invention of claim 1 is an image forming apparatus for forming an image by an electrophotographic system, and a means for instructing power off and the power off. And a means for reading and writing various parameters to and from the backup memory,
It is characterized in that it has means for judging whether or not there is an abnormality in the data of the backup memory, and the write timing to the backup memory is a timing accompanying detection of power off by the means for detecting power off.

The invention of claim 2 further comprises a memory for storing preliminary parameters for the various parameters,
The means for determining the presence or absence of the abnormality determines whether or not the abnormality is a writing error for the various parameters of the backup memory, and if it is recognized as a writing error, stores it in the memory. The backup parameter stored in the backup memory is used as the backup parameter.

According to a third aspect of the present invention, when an abnormality occurs in the data, the read / write means performs the write operation again, and then determines again whether the backup memory is being written. If there is an error during writing, the empty area of the backup memory is searched and only the parameters that can be stored are backed up. Otherwise, the spare parameters in the memory are used as the parameters in the backup memory. It is characterized by

According to a fourth aspect of the present invention, the writing timing to the backup memory is further set for each image formation on a predetermined number of recording sheets.

According to a fifth aspect of the present invention, the write timing to the backup memory is further set every time a predetermined time elapses.

The invention of claim 6 is characterized in that, when the power is turned on, the means for judging the presence / absence of abnormality judges the presence / absence of abnormality of the data in the backup memory.

According to a seventh aspect of the present invention, the storage device further comprises a memory for storing the spare parameter, and when the data abnormality is detected by the judgment at the time of power-on, the spare parameter of the memory is used as the data of the backup memory. It is characterized by doing.

According to an eighth aspect of the present invention, the various parameters are parameters relating to development control performed in the electrophotographic image formation.

According to a ninth aspect of the present invention, the various parameters are parameters relating to fixing control performed in the electrophotographic image formation.

According to a tenth aspect of the invention, there is further provided a sensor for measuring a use environment, and the various parameters are selected according to a measurement result of the sensor.

[0022]

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

(First Embodiment) FIG. 5 is a block diagram showing a printer control mechanism of an image forming apparatus as a first embodiment of the present invention. The same parts as those in the conventional example of FIG. 1 are designated by the same reference numerals. The operation between the printer control circuit 1 and the controller 11 is also the same as the conventional operation timing shown in FIGS. This embodiment is different from the prior art in that an abnormality detecting means 26 for detecting an abnormality in the data of the storage means 10 and a power OFF detection means 13 for determining the timing of data backup are provided. When the printer control circuit 1 is turned on, the printer control circuit 1 reads out data from a backup memory (storage means 10) that stores adjustment value data, high voltage bias, past environmental data, etc. at the time of shipment, and performs initial setting. Start collecting temperature and humidity data. Then, as in the conventional case, the start-up operation is executed until the printer becomes the standby. After that, the printing process is performed by the operation described in the conventional example.

The power-off detection means 13 notifies the image forming apparatus 2 that the various parameters in the RAM are erased because the power-off is detected. ON / OFF of the OFF switch operated by the user is detected, the power supply voltage is monitored,
Although there is a method of detecting a voltage equal to or lower than a predetermined voltage, a conventionally known method can be used, and any method may be used. The power-off instruction means 14 is a means for the image forming apparatus 2 to instruct the power supply unit to be turned off. The power supply switch turns off in response to an instruction from the power supply device, and the power supply unit stops operating. In the present embodiment, when the backup memory writing process is completed after detecting the power OFF, the power OFF instructing means 14 is instructed to turn OFF. The data abnormality detection means 26 determines whether or not the data written or read in the storage means 10 is normal. At the time of writing, the writing in progress flag is set until the end of writing, and at the time of reading, It is checked whether or not the set writing flag remains set, and if it remains set, that is, if it is recognized as a data error, the parameter in the EPROM in the image forming apparatus (preliminary parameter)
Is used as a parameter in the backup memory.

The write processing procedure of this backup memory will be described in detail with reference to the flowchart of FIG.
First, in step S20, the power OFF detection means 13
If the power is detected to be turned off at, the CPU in the image forming apparatus 2 writes various parameters (past temperature / humidity data, currently selected high voltage bias data, etc.) to be stored in the backup memory (storage means 10). Is started (step S21). At this time, the writing flag is also set (step S22). When all parameters have been written (step S23), the process proceeds to step S24, the writing flag set in step S22 is cleared, the power OFF instruction means 14 is instructed to turn off the power, and the process is ended. . As a result, the power is turned off.

Next, the processing procedure of the data abnormality detecting means 26 when the power is turned on will be sequentially described with reference to the flowchart of FIG. When the power is turned on, the CPU in the image forming apparatus first reads out various parameters stored in the backup data (step S30).
And is there any abnormality in the data based on the read parity etc.? Whether or not it is checked (step S31), and if there is no abnormality, the process proceeds to step S11, and the process proceeds to the startup operation up to standby as in the conventional example. If there is an abnormality, it is then determined whether the writing flag remains set (step S32). If the determination is YES in step S32, that is, if the abnormality occurs while the writing flag is set, there is an abnormality such as a momentary interruption during data writing, but the backup memory itself is destroyed. If not, the process proceeds to step S33, the spare parameter stored in the EPROM in the image forming apparatus is treated as a backup memory parameter, and the process proceeds to step S11 in FIG. If the determination is NO in step S32, it is possible that the backup memory itself has been damaged, so the backup parameters stored in the EPROM are rewritten in the backup memory (steps S34, S35). Then, in step S36, various parameters are read again from the backup memory, and it is checked whether or not the read data is abnormal (step S37).

If there is no abnormality, the process proceeds to step S11 and the subsequent operations are executed. If there is an abnormality, the backup memory itself is determined to be abnormal, and as a failure (step S38), the printer controller 11 is notified via the video interface 18, and the machine stops.

As a result, various parameters are saved at the timing of power-off detection, data is guaranteed for grasping the operating environment, and the printer operation due to a write error is also guaranteed. The image quality can be guaranteed.

(Second Embodiment) A second embodiment will be described below. The configuration of the printer control circuit 1 is the same as that of the first embodiment of FIG. 5, and the processing of writing the backup memory accompanying the power OFF detection means 13 and the processing of the data abnormality detection means 26 are the same as those of the first embodiment. different.

In the first embodiment, the write operation to the backup memory is performed at the timing of power OFF detection, and the write flag is used to judge the data abnormality, and the data is guaranteed by the substitution of the parameter. I was going. However, it is difficult to guarantee the data in the case of an instantaneous power failure such as when the outlet is pulled out, and even if only some of the parameters have a write error, other data in the backup memory cannot be made available. In the second embodiment, in the writing operation to the backup memory, even if the power OFF is not detected, a predetermined number of recording sheets of images are formed, or
When the predetermined time has elapsed, the backup write operation is executed. Also, by writing the parameter storage area separately and setting the written flag for each, even if only some of the parameters have a write error, other backup memory data can be used.

FIG. 8 is a flow chart showing the backup memory writing processing procedure in the second embodiment. In the figure, the same steps as those in the first embodiment are the same processes.
First, it is checked whether or not the power OFF is detected by the power OFF detecting means 13 (step S20).
If the FF detection is performed, the process proceeds to step S46. OF
If the F number is not detected, it is checked whether or not a predetermined number of sheets or a predetermined time has passed. In steps S46 to S52, sequential writing operation is performed. Here, first, the written flag is cleared for each writing area, the writing flag is set, and writing is performed for each storage area (for example, one hour temperature / humidity data area, developing high voltage bias area, etc.). When completed, the storage area written flag is set, and when the writing operation for all the storage areas is completed, the in-writing flag is cleared, and step S
Move to 53. Here, the power supply OFF is checked again, and if it is detected to be OFF, the process proceeds to step S25 and ends the process. If not OFF, step S20
Move to. Next, FIG. 9 shows a flowchart showing a processing procedure when the power is turned on in the data abnormality detecting means in the second embodiment. In the figure, the same steps as those in the first embodiment are the same processes.

In the second embodiment, steps S61-63.
As shown in FIG. 5, it is checked whether or not the storage area write flag is set, and the spare parameters in the EPPROM are used only for the storage areas that are not set. As a result, data is guaranteed when the outlet is pulled out, and data in another backup memory can be used even if only some parameters have a write error.Even in an unexpected event, various parameters can be saved and used. Guarantee data for understanding the environment,
Also, the operation of the printer due to the writing error can be guaranteed, and the optimum print image quality can be guaranteed.

In addition to the embodiments described above, the following embodiments can be implemented.

1) In this embodiment, the write data and its storage area are checked for abnormalities when the power is turned on. However, when the power is turned off, the data is read out after the data is backed up to check whether the data storage area is damaged. You may check.

2) In the present embodiment, the image formation is stopped after the damage of the storage area of the write data is found. Instead, however, when the abnormality of the data is detected, the data write operation is performed again, and the error during writing is caused. If a write error occurs (storage area damage error), a free area in the backup memory is searched and the storage area can be stored without being damaged, that is, a readable parameter. It is also possible to re-back up only the data to the free area. Needless to say, a spare parameter of the EPROM may be used as the parameter of the damaged storage area.

[0036]

As described above, according to the first, sixth and seventh aspects.
In the invention, the presence or absence of abnormality in the data in the backup memory is checked, and if there is abnormality, the data is guaranteed by using the spare parameter.

According to the second aspect of the invention, the damage of the data storage area is detected by a plurality of writing processes, and the parameter of the damaged storage area is guaranteed by the spare parameter.

According to the third aspect of the present invention, the parameter of the data storage area which is not damaged is moved to the free area, so that the use of the data storage area which may be damaged is stopped.

According to the fourth and fifth aspects of the invention, the abnormal data is detected earlier by checking whether or not the backup data is abnormal at regular intervals.

According to the eighth, ninth and tenth aspects of the present invention, the reliability of the image forming apparatus is enhanced by protecting the parameters that affect the recording image quality.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a printer control mechanism of an image forming apparatus according to a conventional embodiment.

FIG. 2 is a diagram showing a connection of a video interface.

FIG. 3 is an explanatory diagram illustrating a communication method of a video interface.

FIG. 4 is a flow chart showing a processing procedure of a print sequence means showing a conventional embodiment.

FIG. 5 is a block diagram illustrating a printer control mechanism of the image forming apparatus according to the exemplary embodiment of the present invention.

FIG. 6 is a flowchart showing a backup memory writing processing procedure of the present invention.

FIG. 7 is a flowchart showing a read processing procedure of the data abnormality detecting means of the present invention.

FIG. 8 is a flowchart showing the processing procedure of the second embodiment.

FIG. 9 is a flowchart showing a processing procedure of the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 printer control circuit 2 image forming apparatus 10 storage means 11 printer controller 13 power OFF detection means 14 power OFF instruction means 18 video interface 25 detection means 26 data abnormality detection means

Claims (10)

[Claims] 1. An image forming apparatus for forming an image by an electrophotographic method, means for instructing power off, means for detecting the power off, means for reading / writing various parameters from / to a backup memory, and the backup. An image forming apparatus having a unit for determining whether or not there is an abnormality in data in the memory, wherein the write timing to the backup memory is a timing associated with detection of power off by the unit for detecting power off. 2. A memory for storing spare parameters for the various parameters, further comprising means for judging the presence / absence of the abnormality, wherein the abnormality is a writing error for the various parameters of the backup memory. The image forming apparatus according to claim 1, wherein the backup parameter stored in the memory is used as the backup memory parameter when the writing error is recognized. 3. When an abnormality of the data occurs, the read / write means performs a write operation again, and then determines again whether or not there is an error during writing of the backup memory to determine the presence or absence of the abnormality. If there is an error during writing, search for an empty area in the backup memory and back up only the parameters that can be stored.
3. The image forming apparatus according to claim 2, wherein a spare parameter in the memory is otherwise used as a parameter in the backup memory. 4. The image forming apparatus according to claim 1, wherein the writing timing to the backup memory is set for each image formation on a predetermined number of recording sheets. 5. The image forming apparatus according to claim 1, wherein the write timing to the backup memory is set every time a predetermined time elapses. 6. The image forming apparatus according to claim 1, wherein, when the power is turned on, the means for determining the presence / absence of abnormality determines the presence / absence of abnormality in the data in the backup memory. 7. A backup memory is further provided with a memory for storing the backup parameter, and when the data abnormality is detected by the judgment at the time of power-on, the backup parameter of the memory is used as the data of the backup memory. Claim 6
An image forming apparatus according to claim 1. 8. The image forming apparatus according to claim 1, wherein the various parameters are parameters relating to development control performed in the electrophotographic image formation. 9. The image forming apparatus according to claim 1, wherein the various parameters are parameters relating to fixing control performed in the electrophotographic image formation. 10. The image forming apparatus according to claim 1, further comprising a sensor that measures a use environment, and the various parameters are selected according to a measurement result of the sensor.