JP3754752B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multicolor image forming apparatus that forms a multicolor image by electrophotography.
[0002]
[Prior art]
Conventionally, in this type of apparatus, a multicolor image forming apparatus that forms a multicolor image by an electrophotographic method is provided with a high voltage unit that applies a transfer bias to a transfer charger and a development bias to a development unit according to the number of transfers. Yes. The printer control means sequentially turns on / off the high-pressure unit according to a plurality of recording cycles, thereby forming a multicolor image. FIG. 1 shows a printer control mechanism of this type of multicolor image forming apparatus. In FIG. 1, reference numeral 1 denotes a printer control circuit. Based on the multicolor image signals from the printer controller 11, the image forming apparatus 2 generates a video signal (VDo) 3 and outputs it to the drive circuit 4. This drive circuit 4 is a circuit for driving a semiconductor laser (not shown) and outputs a laser drive signal 5.
[0003]
The image forming apparatus 2 outputs first and second video signals generated from multicolor image signals, forms first and second electrostatic latent images on an image carrier (not shown), and bias control means The start signal 6 to 7 is output. The storage unit 10 stores various parameters relating to the use environment and high-voltage bias (transfer, development) based on the multicolor image signal from the printer controller 11. The bias control means 7 uses the bias data in the storage means 10 and outputs a corresponding bias signal 8 to develop the electrostatic latent image and transfer the recording paper to form a multicolor image.
[0004]
The detection unit 25 notifies the image forming apparatus 2 of, for example, temperature sensor information 23 and humidity sensor information 24. The image forming apparatus 2 grasps the current use environment on the basis of these information and various parameters in the storage unit 10 and selects optimum bias data. Information about the engine at the time of image formation is notified to the printer controller 11 as a status via the video interface 18.
[0005]
Next, the operation between the printer control circuit 1 and the printer controller 11 will be described with reference to FIGS. FIG. 2 shows interface signal lines for 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 sets the / PPRDY signal 121 to true when communication with the printer controller 11 becomes possible after power-on. Then, after confirming that the / CPRDY signal 123 from the printer controller is true, processing for the image forming apparatus 2 to be in a printable state is started. Then, when printing is possible, the / RDY signal 122 is set to true.
[0006]
On the other hand, as shown in FIG. 3, the printer controller 11 sets the / CPRDY signal 123 to true and sets the / CBSY signal 123 to true as shown in FIG. 3, and then synchronizes with the pulse by the CCLK signal 126 to generate the CMD signal. 125 is sent out. Then, after sending a command based on the CDM signal 125, the CBSY signal 124 is set to false. When the printer control circuit 1 receives the command in the above procedure, the printer control circuit 1 sets the SBSY signal 124 to true, and then synchronizes with the pulse by the CCLK signal 126 and transmits the STS signal 128. After sending the status by the STS signal 128, the SBSY signal 127 is set to false. With the above procedure, the printer control circuit 1 and the printer controller 11 transmit and receive commands and statuses. A procedure for the next printing operation will be described.
[0007]
After confirming that the / RDY signal 122 is true, the printer controller 11 sets the / PRNT signal 129 to true. On the other hand, when the printer control circuit 1 recognizes that the / PRNT signal 129 is true as shown in FIG. 3, the printer control circuit 1 starts the pre-rotation operation of the electrophotographic process, and from the detection means 25, it is not shown. After detection of the REJTOP signal TOP portion, a pulse of the / TOP signal 130 is output after t1 time. The printer controller 11 outputs a magenta image signal / VDo 132 in synchronization with the pulse of the LSYNC signal 133. Similarly, cyan, yellow, and black image signals are output to form a multicolor image. Further, the time after detection of the TOP section for each image signal at this time is a value obtained by converting the sensor mounting deviation value for each machine into time, adjusted at the time of shipment, and stored in the storage means 10 of FIG. It is a fixed value.
[0008]
Next, a conventional printing operation will be sequentially described according to a flowchart showing the sequence steps for forming an image of FIG. When the power is turned ON, temperature / humidity data collection is started in order to select the optimal conditions according to the usage environment, initial adjustment of various parameters such as setting of factory adjustment values and high voltage bias data. Is performed (step S10). The process proceeds to step S11, and a start-up process to stand-by that enables a printing operation such as a developing device presence check and a fixing heater temperature control start is executed. However, if a failure is detected by self-diagnosis at this time, a failure occurs. Wait until the fixing temperature reaches the target temperature or the like (step S12), and when it becomes the standby, various environments for judging the use environment from the temperature and humidity data that started the collection and performing optimum printing. A parameter is selected (step S13).
[0009]
This process is performed every 30 minutes of energization, and data for the past 8 hours is stored in the RAM in the image forming apparatus 2 as data for determining the use environment. In this state, whether or not there is a print instruction is also checked (step S14). If there is an instruction, the print sequence of the electrophotographic process is executed (step S15), and an optimum image is output. When the printing operation is completed (step S16), processing for returning to the standby operation is performed, and the operation from step S12 is repeated.
[0010]
[Problems to be solved by the invention]
The conventional image forming apparatus is configured as described above, and performs processing for grasping the use environment for optimum printing every 30 minutes of energization. The data for judging the use environment includes the past 8 hours. Minute data is stored in the RAM. However, when the power is turned off (OFF) due to a user or a momentary power failure, the data accumulated in the past is deleted, and there is a problem that the data becomes insufficient as data for determining the use environment. For this purpose, a method of storing data in the backup memory at regular intervals is conceivable. However, if the writing operation is performed every time the data is collected, the number of times the backup memory is written is limited, and the backup is performed many times. When a memory is used, there arises a problem that the stored data cannot be guaranteed.
[0011]
SUMMARY OF THE INVENTION 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]
[Means for Solving the Problems]
In order to achieve such an object, according to the first aspect of the present invention, in an image forming apparatus that forms an image by an electrophotographic method, a power-off detection unit that detects power-off, and a power-off detection unit that detects power off. A power-off instruction means for instructing to turn off the power after detection of off, a backup memory for storing various parameter data relating to image formation, and a spare memory for storing spare parameter data for the various parameter data; Abnormality detecting means for detecting the presence or absence of abnormality of data stored in the backup memory, and control means for writing the various parameter data to the backup memory when the power-off detecting means detects power-off. And the control means includes the backup memory by the abnormality detection means. When an abnormality of the stored data is detected, it is determined whether an abnormality of the data has occurred during the writing of the data to the backup memory, and as a result of the determination, the abnormality of the data during the writing of the data In the case where it is determined that the occurrence has occurred, the process is executed using the spare parameter stored in the spare memory .
[0013]
According to a second aspect of the present invention, the backup memory has a plurality of storage areas for dividing and storing the various parameters, and the control means writes data to the backup memory for each of the plurality of storage areas. It is determined whether or not the data abnormality has occurred, and as a result of the determination, regarding the various parameter data stored in the storage area that is determined that the data abnormality has occurred during the data writing, the spare data Processing is performed using the preliminary parameter data stored in the memory.
[0014]
The invention of claim 3 is characterized in that the various parameter data are parameter data relating to development control performed in the electrophotographic image formation.
[0015]
According to a fourth aspect of the present invention, the various parameter data are parameter data relating to fixing control performed in the electrophotographic image formation.
The invention of claim 5 further includes a sensor for measuring a use environment, and the various parameter data is selected according to a measurement result of the sensor.
[0022]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0023]
(First embodiment)
FIG. 5 is a block diagram showing a printer control mechanism of the image forming apparatus as the first embodiment of the present invention. The same parts as those in the conventional example of FIG. The operation between the printer control circuit 1 and the controller 11 is also equivalent to 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 data in the storage means 10 and a power OFF detecting means 13 for determining the timing of data backup are provided. When the power 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, and the like at the time of shipment, and performs initial setting. Start collecting temperature and humidity data. Then, a startup operation is performed until the printer enters standby as in the conventional case. Thereafter, the printing process is performed by the operation described in the conventional example.
[0024]
The power OFF detection unit 13 notifies the image forming apparatus 2 that various parameters in the RAM are deleted because OFF is detected. There are methods for detecting ON / OFF of an OFF switch operated by a user and monitoring a power supply voltage to detect a predetermined voltage or less, but conventionally, a well-known method can be used. Good. The power-off instruction unit 14 instructs the image forming apparatus 2 to turn off the power supply unit. The power switch is turned off by an instruction from the power supply apparatus, and the power supply unit stops its operation. In this embodiment, when the backup memory writing process is completed after detecting the power OFF detection, the power OFF instruction means 14 is instructed to turn OFF. The data abnormality detection unit 26 determines whether the data written or read in the storage unit 10 is normal. At the time of writing, the writing flag is set until the end of writing. It is checked whether the set writing flag remains set. If it is set, that is, if it is recognized as a data error, the EPROM parameter (preliminary parameter) in the image forming apparatus is stored in the backup memory. The processing such as setting the parameters is performed.
[0025]
The backup memory write processing procedure will be described in detail with reference to the flowchart of FIG. First, if the power OFF detection means 13 detects that the power OFF is detected in step S20, the CPU in the image forming apparatus 2 stores various parameters (past temperature / humidity data, current selection) 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). If 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 unit 14 is instructed to turn off the power, and the process is terminated. . As a result, the power is turned off.
[0026]
Next, the processing procedure when the power is turned on in the data abnormality detection means 26 will be described in sequence 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). Then, it is checked whether or not there is an abnormality in the data based on the read parity or the like (step S31). If there is no abnormality, the process proceeds to step S11, and the process proceeds to the start-up operation until standby as in the conventional example. If there is an abnormality, it is next determined whether or not the writing flag remains set (step S32). If the determination in step S32 is YES, that is, if an abnormality occurred while the writing flag was set, there was an abnormality such as an instantaneous stop during data writing, but the backup memory itself was broken. 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 in step S32 is NO, the backup memory itself may be damaged, so the spare parameters stored in the EPROM are written again in the backup memory (steps S34 and S35). In step S36, various parameters are read from the backup memory again, and it is checked whether or not the read data is abnormal (step S37).
[0027]
If there is no abnormality, the process proceeds to step S11, and the subsequent operations are executed. If there is an abnormality, it is determined that the backup memory itself is abnormal, a failure (step S38) is notified to the printer controller 11 via the video interface 18, and the machine stops.
[0028]
As a result, various parameters are saved at the timing of power-off detection, data for ascertaining the usage environment can be guaranteed, and printer operation can also be guaranteed due to write errors, ensuring optimum print image quality. Can be planned.
[0029]
(Second embodiment)
The second embodiment will be described below. The configuration of the printer control circuit 1 is the same as that of the first embodiment shown in FIG. 5, and the backup memory writing process associated with the power OFF detection means 13 and the data abnormality detection means 26 are the same as those of the first embodiment. Different.
[0030]
In the first embodiment, the write operation to the backup memory is performed at the timing of detecting the power OFF, the data abnormality is determined by the write flag, and the data is guaranteed by substituting the parameter. . However, it is difficult to guarantee data in the event of an instantaneous power failure such as when the outlet is pulled out, and other data in the backup memory cannot be made available even if only some parameters are write errors. In the second embodiment, in the writing operation to the backup memory, the backup writing operation is executed when a predetermined number of sheets of recording paper are formed or a predetermined time elapses even if power OFF is not detected. In addition, the parameter storage area is divided and written, and each written flag is set, so that even if some parameters are write errors, other data in the backup memory can be used.
[0031]
FIG. 8 is a flowchart showing the backup memory write processing procedure in the second embodiment. In the figure, the same steps as those in the first embodiment are the same processing. First, it is checked whether or not the power OFF detection means 13 has detected the power OFF (step S20). If the power OFF is detected, the process proceeds to step S46. If it is not OFF detection, it is checked whether a predetermined number of sheets or a predetermined time has elapsed, and if it has elapsed, the process proceeds to step S46. In steps S46 to S52, sequential writing operations are performed. Here, first, the written flag for each writing area is cleared and the writing flag is set, and writing is performed for each storage area (for example, an area for 1 hour of temperature and humidity data, a development high-voltage bias area, etc.). If completed, the storage area written flag is set, and if the writing operation of all the storage areas is completed, the writing flag is cleared and the process proceeds to step S53. Here, the power supply OFF is checked again, and if OFF is detected, the process proceeds to step S25 and the process is terminated. If not OFF, the process proceeds to step S20. Next, FIG. 9 is a flowchart showing a processing procedure when the power is turned on in the data abnormality detection means in the second embodiment. In the figure, the same steps as those in the first embodiment are the same processing.
[0032]
In the second embodiment, as shown in step S61～63, which storage area write flag performs a check whether it is set, using the preliminary parameters in EPPROM only storage area has not been set It is. As a result, data is guaranteed when the outlet is pulled out, and data in other backup memory can be used even if only some parameters are write errors, and various parameters can be saved and used even in the event of an unexpected event. Data for ascertaining the environment can be guaranteed, and printer operation can be guaranteed due to writing errors, so that optimum print image quality can be guaranteed.
[0033]
In addition to the embodiments described above, the following embodiments can be implemented.
[0034]
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 after data backup to check whether the data storage area is damaged. Also good.
[0035]
2) In this embodiment, image formation is stopped after finding a damage to the storage area of the write data. Instead, when data abnormality is detected, the data write operation is performed again to check whether there is an error during writing. performing judgment, the case where a writing in error (corruption errors of the storage area), looking for a free space of the backup memory, can be stored in the area storage area is not damaged, i.e., readable parameter data It is also possible to back up only to the above free space. It goes without saying that EPROM reserve parameters may be used as parameters for the damaged storage area.
[0036]
【The invention's effect】
As described above, according to the first aspect of the present invention, when it is determined that a data abnormality has occurred during the writing of data to the backup memory when the abnormality of the data in the backup memory is detected, the spare parameter data is By using it, it is possible to execute processing, and it is possible to guarantee the operation of the printer when an abnormality occurs during data writing.
[0037]
According to the invention of claim 2, when some parameters in the backup memory are errors, the data in the backup memory that is not other errors can be used, and the printer operation when an abnormality occurs during data writing A guarantee can be made.
[0040]
According to the third, fourth, and fifth aspects of the invention, the reliability of the image forming apparatus is enhanced by protecting the parameter data that affects the recording image quality.
[Brief description of the 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 video interface connections;
FIG. 3 is an explanatory diagram for explaining a video interface communication method;
FIG. 4 is a flowchart showing a processing procedure of a printing 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 write processing procedure of the present invention.
FIG. 7 is a flowchart showing a read processing procedure of the data abnormality detection means of the present invention.
FIG. 8 is a flowchart showing a 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 Memory | storage means 11 Printer controller 13 Power supply OFF detection means 14 Power supply OFF instruction means 18 Video interface 25 Detection means 26 Data abnormality detection means

Claims (5)

In an image forming apparatus that forms an image by electrophotography,
Power off detection means for detecting power off;
A power-off instruction means for instructing to turn off the power after the power-off detection means detects the power-off,
A backup memory for storing various parameter data related to image formation;
Spare memory for storing spare parameter data for the various parameter data;
An abnormality detection means for detecting the presence or absence of an abnormality in the data stored in the backup memory;
Control means for writing the various parameter data to the backup memory when the power-off detection means detects power-off.
The control means, when detecting an abnormality of the data stored in the backup memory by the abnormality detection means, determines whether an abnormality of the data has occurred during the writing of data to the backup memory, As a result of the determination, if it is determined that an abnormality of the data has occurred during the writing of the data, the image forming apparatus performs processing using the spare parameter stored in the spare memory . The backup memory has a plurality of storage areas that divide and store the various parameters, and the control means detects the abnormality of the data during the writing of data to the backup memory for each of the plurality of storage areas. It is determined whether or not it has occurred, and as a result of the determination, the various parameter data stored in the storage area that has been determined that the data abnormality has occurred during the writing of the data is stored in the spare memory. The image forming apparatus according to claim 1, wherein the processing is executed using the preliminary parameter data. The image forming apparatus according to claim 1, wherein the various parameter data are parameter data relating to development control performed in the electrophotographic image formation. 2. The image forming apparatus according to claim 1, wherein the various parameter data are parameter data relating to fixing control performed in the electrophotographic image formation. The image forming apparatus according to claim 1, further comprising a sensor that measures a use environment, wherein the various parameter data is selected according to a measurement result of the sensor.

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