JP3768947B2 - Image forming apparatus, program, and control apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus having a color-specific maintenance operation.
[0002]
[Prior art]
As an important technique in a color image forming apparatus, a technique of superposing toner images of four colors of yellow (hereinafter referred to as Y), magenta (hereinafter referred to as M), cyan (hereinafter referred to as C), and black (hereinafter referred to as K) without deviation. There is. Basically, the writing timing of each color is adjusted based on the reference image writing timing signal, and a good image without color misregistration is created. However, in reality, the transfer belt 333 (also referred to as a paper transport belt) expands and contracts due to environmental conditions, the progress of durability, and the like, resulting in a deviation in the overlay result of each color.
[0003]
As a solution to this, there is an automatic registration adjustment mechanism. The auto registration adjustment mechanism prints a specific mark on the transfer belt every predetermined number of sheets, reads the specific mark with a sensor installed on the transfer belt, detects the circumference of the transfer belt, and performs feedback control on the image writing timing. It is to call.
[0004]
[Problems to be solved by the invention]
However, the auto-registration adjustment mechanism needs to be adjusted every predetermined number of sheets, and when the predetermined value is reached during a job, the job is interrupted and the adjustment mechanism is used, which causes a problem of reducing productivity. In particular, for a user who needs to print a large number of jobs in a short time, interruption of the job should be avoided as much as possible.
[0005]
[Means for Solving the Problems]
The present invention has been made in view of the above circumstances. The invention according to claim 1 is an image forming unit that forms a monochrome or color image on a sheet, and the image forming unit forms a color image on the sheet. A discriminating means for discriminating the number of times and the number of times the black-and-white image has been formed on the sheet; Automatic registration adjustment timing that prevents color misregistration for each color component that occurs when an image is formed on a sheet And when the current job is a color job, the control means determines whether the number of times that the color image has been formed on the sheet has reached a predetermined number of times. Even said Auto cash register adjustment If the current job is a black and white job, even if the number of times that the black and white image has been formed on the sheet has reached the predetermined number, Auto cash register adjustment After the job is finished It is determined whether the number of times that the black and white image has been formed on the sheet has reached a predetermined number. If the predetermined number has been reached, the auto registration adjustment is performed. It is characterized by performing.
[0006]
Claim 5 The present invention relates to a program for performing a maintenance operation on an image forming apparatus having an image forming unit that forms a black and white or color image on a sheet, and the number of times the image forming unit forms a color image on the sheet. And a determination procedure for determining the number of times the black and white image has been formed on the sheet, and a color according to the value determined by the determination procedure. Controls the timing of auto registration adjustment that prevents color misregistration for each color component that occurs when an image is formed on a sheet If the current job is a color job in the control procedure, the number of times that the color image is formed on the sheet has reached a predetermined number of times. Auto cash register adjustment If the current job is a black and white job, even if the number of times that the black and white image has been formed on the sheet has reached the predetermined number, Auto cash register adjustment After the job is finished It is determined whether the number of times that the black and white image has been formed on the sheet has reached a predetermined number. If the predetermined number has been reached, the auto registration adjustment is performed. It is characterized by having an arithmetic unit execute that.
[0007]
Claim 6 The present invention relates to a control device for controlling the timing of performing a maintenance operation on an image forming apparatus having an image forming means for forming a monochrome or color image on a sheet, wherein the image forming means outputs a color image. A discriminating unit for discriminating the number of times the sheet has been formed and the number of times the black-and-white image has been formed on the sheet; Auto registration adjustment to prevent color misregistration for each color component that occurs when an image is formed on a sheet And when the current job is a color job, the control unit determines whether the number of times that the color image has been formed on the sheet has reached a predetermined number of times. Even inside Auto cash register adjustment If the current job is a black and white job, even if the number of times that the black and white image has been formed on the sheet has reached the predetermined number, Auto cash register adjustment After the job is finished It is determined whether the number of times that the black and white image has been formed on the sheet has reached a predetermined number. If the predetermined number has been reached, the auto registration adjustment is performed. It is characterized by performing.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
First, a general four-drum color image forming apparatus will be described with reference to FIG. Reference numeral 101 denotes a CCD, 311 denotes a substrate on which the CCD 101 is mounted, 312 denotes an image processing unit, 301 denotes an original platen glass, 302 denotes a document feeder (DF) (note that a mirror surface (not shown) is used instead of the document feeder 302) (There is also a configuration equipped with a pressure plate), 303 and 304 are light sources (halogen lamps or fluorescent lamps) for illuminating the original, 305 and 306 are reflectors for condensing the light of the light sources 303 and 304 on the original, and 307 to 309 are mirrors , 310 is a lens for condensing the reflected light or projection light from the document on the CCD 101, 314 is a carriage that houses the halogen lamps 303 and 304, the reflectors 305 and 306, and the mirror 307, and 315 is that that houses the mirrors 308 and 309. A carriage 313 is an interface (I / F) unit with another IPU or the like. The carriage 314 is moved at a speed V and the carriage 315 is moved at a speed V / 2 in a direction perpendicular to the electrical scanning (main scanning) direction of the CCD 101, thereby scanning the entire surface of the document (sub scanning). )
[0009]
Reference numeral 317 denotes a Y image forming unit, 318 denotes an M image forming unit, 319 denotes a C image forming unit, and 320 denotes a K image forming unit. Since the respective configurations are the same, the Y image forming unit 317 will be described in detail and other image forming operations will be described. Description of the part is omitted. In the Y image forming unit 317, reference numeral 342 denotes a photosensitive drum, and a latent image is formed on the surface thereof by light from the LED array 210. Reference numeral 321 denotes primary band electricity, which charges the surface of the photosensitive drum 342 to a predetermined potential to prepare for latent image formation. A developing unit 322 develops the latent image on the photosensitive drum 342 to form a toner image. The developing device 322 includes a sleeve 345 for applying a developing bias for development. Reference numeral 323 denotes transfer band electricity, which discharges from the back surface of the transfer belt 333 and transfers the toner image on the photosensitive drum 342 to a recording sheet or the like on the transfer belt 333. The residual toner that could not be transferred is collected in the cleaner unit 360 by the cleaner blade 361.
[0010]
Next, a procedure for forming an image on recording paper will be described. Recording paper or the like stored in the cassettes 340 and 341 is supplied onto the transfer belt 333 by pickup rollers 338 and 339 by sheet feeding rollers 336 and 337 one by one. The fed recording paper is charged by an adsorption charger 346. Reference numeral 348 denotes a transfer belt roller that drives the transfer belt 333 and charges the recording paper or the like in a pair with the adsorption charger 346 to adsorb the recording paper or the like to the transfer belt 333. Reference numeral 347 denotes a paper front end sensor that detects the front end of a recording paper or the like on the transfer belt 333. The detection signal of the paper leading edge sensor is sent from the printer unit to the color reader unit, and is used as a sub-scanning synchronization signal when a video signal is sent from the color reader unit to the printer unit.
[0011]
Thereafter, the recording paper or the like is conveyed by the transfer belt 333, and toner images are formed on the surface in the order of YMCK in the image forming units 317 to 320. The recording paper or the like that has passed through the K image forming unit 320 is separated from the transfer belt 333 after being neutralized by the neutralization charger 349 to facilitate separation from the transfer belt 333. A peeling charger 350 prevents image disturbance due to peeling discharge when the recording paper or the like is separated from the transfer belt 333. The separated recording paper or the like is charged by the pre-fixing chargers 351 and 352 and then the toner image is thermally fixed by the fixing device 334 in order to compensate for the toner adsorption force and prevent image disturbance. The paper is discharged to the paper discharge tray.
[0012]
Next, LED image recording will be described. The YMCK image signal generated by the image processing unit is divided into four colors by adjusting the difference in distance between the paper leading end sensor and each image forming unit by delay processing based on the paper leading end signal from the paper leading end sensor 347. It is possible to print at a predetermined position.
[0013]
Next, black belt adjustment will be described as an example of a common maintenance operation performed for each predetermined value in common for black and white and color regardless of black and white jobs and color jobs. The black belt adjustment is performed periodically in order to prevent the cleaner blade 361 that is in contact with the transfer belt 333 after passing a predetermined number of sheets from being turned due to an increase in frictional force with the transfer belt 333. In the paper passing state, a slight amount of toner is transferred onto the transfer belt 333 in a belt shape in a direction perpendicular to the rotation direction of the transfer belt 333 using K toner. As a result, the frictional force between the cleaner blade 361 and the transfer belt 333 is reduced, and the cleaner blade 361 that has been turned over is restored to its original state by itself. As described above, the black belt adjustment is a maintenance operation for preventing the cleaner blade 361 from turning up.
[0014]
Next, as with the black band adjustment, density adjustment will be described as an example of a common maintenance operation performed for each predetermined value in common for black and white and color regardless of black and white jobs and color jobs. Density adjustment is an adjustment to keep the density of an image to be formed constant. After passing a predetermined number of sheets, a predetermined pattern is formed on the transfer belt 333 with YMCK toner, and the image is actually formed. By detecting the density of the formed image by the sensor 399, the density is judged and the density for image formation is adjusted.
[0015]
Next, auto registration adjustment will be described with reference to FIGS. The auto registration adjustment function is an example of a maintenance operation unique to a color job. As one of the auto registration adjustment techniques, for example, a specific mark 398 is printed on the transfer belt 333 by the K image forming unit 320, and a sensor 399 that detects the specific mark 398 rotates the transfer belt 333 one or more times. The expansion / contraction of the transfer belt 333 is calculated from the output. For example, when the calculation result is longer than the reference value, it can be seen that the transfer belt 333 is extended. At the time of the next image formation, the value of the transfer belt 333 is increased by the first Y image forming unit 317. By controlling the image formation timing (in this case, the light emission timing of the LED 210) to delay the image formation timing of each of the image forming units 318 to 320 of the MCK, control for maintaining the overlay accuracy of the four colors is performed. Yes. For this reason, when the auto registration adjustment is performed, as described above, the rotation (one round or more) for detecting the expansion / contraction of the transfer belt 333 is required, and the job is interrupted.
[0016]
Control in conventional automatic registration adjustment will be described with reference to the flowchart of FIG. Conventionally, a counter 415 that counts the total number of images formed regardless of color / monochrome is provided, and a setting value α that represents the timing for performing auto registration adjustment is stored in the storage unit 403.
[0017]
First, 1 is added to the counter 415 (S110), and the comparison unit 405 determines whether or not the counter value is equal to or larger than the set value α stored in the storage unit 416 (S111). When the counter value is equal to or greater than the set value α, the adjustment control unit 406 performs auto registration adjustment (S112), and the image formation control unit 404 performs image formation operation (S113). If it is determined in S111 that the counter value is less than α, image formation is performed without performing auto registration adjustment (S113). When image formation is completed in S113, it is determined whether the job is completed (S114). If the job is completed, the flowchart is ended. If the job has not ended in S114, the process returns to S110.
[0018]
FIG. 4 shows a block diagram of a color image forming apparatus according to an embodiment of the present invention. As shown in FIG. 4, a monochrome counter 401 and a color counter 402 are separately provided, a set value α indicating the timing for performing a maintenance operation (auto registration adjustment) unique to a color job, and a maintenance operation (black) common to a color job and a monochrome job. A setting value β representing the timing of performing band adjustment and density adjustment is stored in advance in a storage unit 403 such as a backup memory. Further, an adjustment control unit 406 that performs maintenance operations such as auto registration adjustment and black band adjustment, and an image formation control unit 404 that controls image formation operations are provided. The adjustment control unit 406 includes a ROM 421 that stores a program for performing a maintenance operation, a CPU 420 that executes the program stored in the ROM 421, and a RAM 422 that supplies a working area necessary for the CPU 420 to operate. .
[0019]
[First Embodiment]
In the first embodiment, a total counter 400 is provided, and the sum of the number of color and monochrome image formations is counted as in the counter 415 described above. In the following description, auto-registration adjustment is described as an example of a color-specific maintenance operation, and black belt adjustment is described as an example of a maintenance operation common to color black and white.
[0020]
The control of the color image forming apparatus 410 in the first embodiment is shown in the flowchart of FIG. First, 1 is added to the total counter 400 (S100). Next, it is determined whether the identified result from the image reading device 407 (for example, reader) for identifying whether it is a monochrome job or a color job is color or monochrome (S101). If it is determined that the image is black and white, it is determined whether or not the value of the total counter 400 is equal to or greater than the set value β stored in the storage unit 403 (S102). If it is determined in S102 that the value of the total counter 400 is equal to or larger than the set value β, black band adjustment is performed (S103), the total counter 400 is reset (zero clear) (S104), and an image is formed on the sheet (S105). ). When it is determined in S102 that the value of the total counter 400 is less than the set value β, an image is formed on the sheet without performing black band adjustment (S105). When an image is formed on one sheet in S105, it is determined whether or not the job is finished (S106). If the job is finished, the flowchart is finished. If the job is not completed in S106, the process returns to S100 to continue the process in order to form an image on the next sheet.
[0021]
If it is determined in S101 that the color is present, 1 is added to the color counter 402 (S107), and it is determined whether or not the value of the color counter 402 is equal to or greater than the set value α (S108). If it is less than the set value α, the process proceeds to S102 described above, and if it is greater than the set value α, auto registration adjustment is performed (S109), the color counter is reset (zero cleared) (S110), and the process proceeds to S102 described above.
[0022]
As described above, when a large number of jobs are performed in the black and white mode, the maintenance operation (auto registration adjustment) unique to the color job performed every predetermined number of sheets is not executed. That is, since the black-and-white job is prevented from being interrupted, the productivity of the black-and-white job can be improved.
[0023]
Next, actual effects will be described with reference to FIGS. 6 to 9, the set value α for performing the maintenance operation (auto registration adjustment) unique to the color job is 200 sheets. FIG. 6 shows control according to the prior art. Job settings are 250 black and white jobs and 50 color jobs. In the conventional technique, since the maintenance operation is performed when the value of the total counter 400 reaches 200 sheets, the end time of the job is delayed by t1 time compared to the case where the maintenance operation is not performed.
[0024]
On the other hand, FIG. 7 showing the first embodiment does not perform the maintenance operation until the value of the color counter 402 reaches 200 even if the number of black-and-white images formed exceeds 200. There is no delay t1 in time.
[0025]
FIG. 8 shows a conventional technique in a setting including a maintenance operation (auto registration adjustment) unique to a color job and a maintenance operation (black band adjustment) common to a color job and a monochrome job. The job settings in FIG. 8 are 250 black and white jobs and 150 color jobs. In the prior art, black belt adjustment is performed when the total counter 400 reaches 150 sheets, and automatic registration adjustment (described as registration adjustment in the figure) is performed when the counter further advances to 200 sheets. Similarly, black belt adjustment is performed when the counter reaches 300 sheets, and automatic registration adjustment is performed when the counter reaches 400 sheets. Therefore, the total job end delay time is t2a = t1 + 2t2.
[0026]
On the other hand, in FIG. 9 which is the first embodiment, the auto registration adjustment does not perform the maintenance operation until the color counter 402 reaches 200 sheets even when the number of black and white image formation exceeds 200 sheets, and the black belt adjustment. Is performed every time the total counter 400 representing the total number of black and white and color images formed reaches 150. Therefore, the job end delay time is t2b = 2t2, and the result t2a> t2b reduces the job end time (production Improvement).
[0027]
[Second Embodiment]
FIG. 10 shows a flowchart representing the control in the second embodiment. In FIG. 10, the maintenance operation (black band adjustment) common to the color job and the black-and-white job is the same as that in the first embodiment described above, and a description thereof will be omitted.
[0028]
First, it is determined whether the result of identification by an image reading device 407 (for example, a reader) for identifying a monochrome job or a color job is color or monochrome (S120). If it is monochrome, the value of the monochrome counter 401 is incremented by 1 (S121), and an image is formed on the sheet (S122). When the image formation is completed, it is determined whether or not the job is completed (S123), and if not completed, the process returns to S120 described above. If it is determined in S123 that the job has ended, it is determined whether or not the value of the black and white counter 401 is greater than or equal to the set value α stored in the storage unit 403 (S124). If the value of the black and white counter 401 is greater than or equal to α, auto registration adjustment is performed (S129), the value of the black and white counter 401 is reset (zero cleared) (S130), and the flowchart ends. If the value of the black-and-white counter 401 is less than α in S124, the flowchart ends without performing automatic registration adjustment.
[0029]
In S120 described above, when it is determined that the result identified by the image reading device 407 for identifying whether the job is a monochrome job or a color job is color, the value of the color counter 402 is incremented by 1 (S125). Thereafter, it is determined whether or not the color counter 402 is greater than or equal to the set value α stored in the storage unit 403 (S126). If the value of the color counter 402 is greater than or equal to the set value α, auto registration adjustment is performed (S127), the value of the color counter 402 is reset (zero cleared) (S128), and the process proceeds to S123 described above. If the value of the color counter 402 is less than the set value α in S126, the process proceeds to S123 described above without performing auto registration adjustment.
[0030]
As described above, in this embodiment, even after a large amount of black and white jobs are performed, by comparing the value of the black and white counter 401 with the set value α, a maintenance operation (auto registration adjustment) unique to the color job is performed in the free time. Therefore, it is possible to prevent the productivity of black and white jobs from being reduced.
[0031]
Next, actual effects will be described with reference to FIGS. 6 and 11, the set value α for performing the maintenance operation (auto registration adjustment) unique to the color job is 200 sheets. FIG. 6 shows control according to the prior art. The job settings are 250 black and white jobs and 50 color jobs. In the conventional technique, since the maintenance operation is performed when the value of the total counter 400 reaches 200 sheets, the end time of the job is delayed by t1 time compared to the case where the maintenance operation is not performed. On the other hand, FIG. 10 of this embodiment counts monochrome jobs and color jobs with separate counters, and even if the monochrome counter 401 exceeds 200 sheets, the maintenance operation is performed until the color counter 402 reaches 200 sheets. Therefore, the delay t1 does not occur in the job end time. Then, the monochrome counter 401 and the set value α are compared, and the set value α = 200 <monochrome counter value = 250, so that the auto registration adjustment is performed at the free time after the end of all jobs. Thereby, it is possible to prevent the productivity of the black and white job from being reduced.
[0032]
[Third Embodiment] FIG. 12 is a flowchart showing the control in the third embodiment. In FIG. 12, the maintenance operation (black band adjustment) common to the color job and the black and white job is the same as that in the first embodiment, and the description thereof is omitted.
[0033]
First, it is determined whether the result of identification by an image reading device 407 (for example, a reader) for identifying whether it is a monochrome job or a color job is color or monochrome (S131). If it is black and white, the value of the black and white counter 401 is incremented by 1 (S132), and an image is formed on the sheet (S133). When the image formation is finished, it is determined whether or not the job is finished (S134), and if not finished, the process returns to S131 described above. If it is determined in S134 that the job has been completed, it is determined whether the next job is color (S135). If the next job is color, it is determined whether the monochrome counter 401 is greater than or equal to α (S136). If it is greater than or equal to α, auto registration adjustment is performed (S141), and the monochrome counter 401 is reset (zero cleared). (S142), and the flowchart ends. If it is determined in S135 that the next job is not a color, or if the monochrome counter 401 is less than α in S136, the flowchart ends without performing auto registration adjustment.
[0034]
In S131 described above, when it is determined that the result identified by the image reading device 407 for identifying whether the job is a monochrome job or a color job is color, the value of the color counter 402 is incremented by 1 (S137). Thereafter, it is determined whether or not the color counter 402 is greater than or equal to the set value α stored in the storage unit 403 (S138). When the value of the color counter 402 is equal to or larger than the set value α, auto registration adjustment is performed (S139), the color counter 402 is reset (zero cleared) (S140), and the process proceeds to S133 described above. If the value of the color counter 402 is less than the set value α in S138, the process proceeds to S133 described above without performing auto registration adjustment.
[0035]
In this way, if the current job is a black and white job and the next job is a color job, at least interrupt the current job by executing maintenance operations specific to the color job after the current job ends Therefore, the productivity of black and white jobs can be prevented from being reduced.
[0036]
Next, actual effects will be described with reference to FIGS. 13 and 14, the set value α for performing the maintenance operation (auto registration adjustment) unique to the color job is 200 sheets. FIG. 13 shows control according to the prior art. The job setting is 250 sheets for the current monochrome job and 50 sheets for the reserved job. In the conventional technique, since the maintenance operation is performed when the counter reaches 200, the job end time is delayed by t3 hours compared to the case where the maintenance operation is not performed. On the other hand, FIG. 14 of this embodiment counts monochrome jobs and color jobs with separate counters, and even if the monochrome counter 401 exceeds 200 sheets, the maintenance operation is performed until the color counter 402 reaches 200 sheets. Therefore, there is no delay t3 in the end time of the current job. Since the current job is a black and white job and the reserved job is a color job, it can be completed without interrupting at least the current job by performing a maintenance operation (auto registration adjustment) unique to the color job after the current job ends. Productivity reduction (equivalent to t3) can be prevented.
[0037]
In the above description, a case where a reader (image reading device 407) is mounted as an image input unit has been described. This is a personal computer (PC) 409 connected to the color image forming apparatus 410 via the network controller 408. However, since information indicating whether the job is a monochrome job or a color job is transmitted from the personal computer (PC) 409, it is possible to identify whether the job is monochrome or color, and thus the same effect can be obtained. it can.
[0038]
If there are a plurality of job counters, the invention is not limited to the black and white counter 401 and the color counter 402. For example, the combination of the total counter 400 and the color counter 402 or the combination of the total counter 400 and the monochrome counter 401 can be implemented with a slight change in configuration.
[0039]
Further, instead of providing hardware counters such as the black and white counter 401, the color counter 402, and the total counter 400, counting may be performed on a program stored in the ROM 421 to determine the counted value.
[0040]
Further, it is possible to determine the number of times that a color image has been formed on the sheet, perform a color-specific maintenance operation, and perform timing control of the maintenance operation with a single controller.
[0041]
【The invention's effect】
As explained above, Book According to the invention, if the current job is a color job, the control means can determine whether the number of times that the color image has been formed on the sheet has reached a predetermined number, even during the job. Auto cash register adjustment If the current job is a black and white job, even if the number of times that the black and white image has been formed on the sheet has reached the predetermined number, Auto cash register adjustment After the job is finished Judge whether the number of times the black-and-white image has been formed on the sheet has reached the predetermined number, and if it has reached the predetermined number, auto registration adjustment During monochrome image forming operation. Auto cash register adjustment Can prevent the image forming operation from being interrupted by Even after a large amount of black and white jobs are done, it is possible to determine whether or not to perform auto registration adjustment, and to perform auto registration adjustment at an appropriate timing. be able to.
[Brief description of the drawings]
FIG. 1 is a diagram showing a general four-drum color image forming apparatus.
FIG. 2 is a block diagram illustrating a conventional image forming apparatus.
FIG. 3 is a flowchart showing control in conventional auto registration adjustment.
FIG. 4 is a block diagram showing a color image forming apparatus according to the present invention.
FIG. 5 is a flowchart showing control of the color image forming apparatus in the first embodiment.
FIG. 6 is a diagram illustrating a timing at which a maintenance operation is interrupted in the related art.
FIG. 7 is a diagram illustrating a timing at which a maintenance operation is interrupted in the first embodiment.
FIG. 8 is a diagram illustrating the timing at which auto registration adjustment and black belt adjustment are interrupted in the prior art.
FIG. 9 is a diagram illustrating an interrupt timing of automatic registration adjustment and black belt adjustment in the first embodiment.
FIG. 10 is a flowchart illustrating control of a color image forming apparatus according to a second embodiment.
FIG. 11 is a diagram illustrating a timing at which a maintenance operation is interrupted in the second embodiment.
FIG. 12 is a flowchart illustrating control of a color image forming apparatus according to a third embodiment.
FIG. 13 is a diagram illustrating a timing at which a maintenance operation is interrupted in the related art.
FIG. 14 is a diagram illustrating a timing at which a maintenance operation is interrupted in the third embodiment.
[Explanation of symbols]
317 Y image forming unit
318 M image forming unit
319 C image forming unit
320K image forming unit
333 transfer belt
401 Black and white counter
402 Color counter
403 storage unit
404 Image formation controller
405 comparison unit
406 Adjustment control unit
407 Image reading unit
410 color image forming apparatus

Claims (6)

Image forming means for forming a monochrome or color image on a sheet;
A discriminating unit for discriminating the number of times that the image forming unit forms a color image on the sheet and the number of times that the black and white image is formed on the sheet;
Control means for controlling the timing of performing automatic registration adjustment for preventing color misregistration for each color component generated when forming a color image on a sheet according to the value determined by the determination means;
If the current job is a color job, the control means performs the auto registration adjustment even during the job in response to the number of times the color image is formed on the sheet reaching the predetermined number of times. If the job is a black and white job, the auto registration adjustment is not performed during the job even if the number of times that the black and white image is formed on the sheet reaches the predetermined number, and the number of times that the black and white image is formed on the sheet after the job is completed is the predetermined number of times. The image forming apparatus is characterized in that the automatic registration adjustment is performed when the predetermined number of times is reached . Conveying means for conveying a sheet so that the image forming means forms an image;
A cleaner blade disposed so as to contact the conveying means;
The control means, depending on the number of times the image forming means has an image formed on the sheet, that you control the timing of the black belt adjustment which the cleaner blade is prevented from being turned over by friction with the conveying means The image forming apparatus according to claim 1, wherein: An identification means for identifying whether the image to be formed on the sheet by the image forming means is a monochrome image or a color image;
The image forming apparatus according to claim 1, wherein the determination unit counts the number of times the image forming unit has formed a color image on a sheet based on the identification result of the identification unit. The image forming apparatus according to claim 1, further comprising a storage unit that stores a setting value indicating a timing at which the automatic registration adjustment is performed by the control unit. A program for performing a maintenance operation on an image forming apparatus having an image forming means for forming a monochrome or color image on a sheet,
A determination procedure for determining the number of times that the image forming unit has formed a color image on the sheet and the number of times that the black and white image has been formed on the sheet;
A control procedure for controlling the timing of performing auto registration adjustment for preventing color misregistration for each color component that occurs when a color image is formed on a sheet according to the value determined by the determination procedure;
In the control procedure, when the current job is a color job, the automatic registration adjustment is performed even during the job in response to the number of times that the color image is formed on the sheet reaches a predetermined number. If the job is a black and white job, the auto registration adjustment is not performed during the job even if the number of times that the black and white image is formed on the sheet reaches the predetermined number, and the number of times that the black and white image is formed on the sheet after the job is completed is the predetermined number of times. And a program for causing the arithmetic unit to execute the auto registration adjustment when the predetermined number of times has been reached . A control device for controlling the timing of performing a maintenance operation on an image forming apparatus having an image forming means for forming a monochrome or color image on a sheet,
A discriminating unit for discriminating the number of times that the image forming unit forms a color image on the sheet and the number of times that the black and white image is formed on the sheet;
Depending on the value that is determined by the previous SL discriminating means, and control means for controlling the timing of Otoreji adjustment to prevent the color shift of each color component generated at the time of forming a color image on a sheet,
If the current job is a color job, the control means performs the auto registration adjustment even during the job in response to the number of times the color image is formed on the sheet reaching the predetermined number of times. If the job is a black and white job, the auto registration adjustment is not performed during the job even if the number of times that the black and white image is formed on the sheet reaches the predetermined number, and the number of times that the black and white image is formed on the sheet after the job is completed is the predetermined number of times. The control apparatus is characterized in that it is determined whether or not a predetermined number of times has been reached and if the predetermined number of times has been reached, the automatic registration adjustment is performed.

Images