JP2004126428A - Image forming apparatus, program, controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which interruption of image forming operation due to maintenance operation peculiar to color image formation is prevented during black-and-white image forming operation by controlling the timing of the maintenance operation by a control means in accordance with a value discriminated by a discrimination means. <P>SOLUTION: The image forming apparatus has an image forming means for forming black-and-white or color images on sheets, a color counter 402 for counting the frequency in which the image forming means has formed color images on sheets, and an adjustment control part 406 for performing the maintenance operation peculiar to color image formation, and the adjustment control part 406 controls the timing of the maintenance operation peculiar to color image formation in accordance with a value counted by the color counter 402. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus having a maintenance operation unique to a color.
[0002]
[Prior art]
One of important technologies in a color image forming apparatus is a technology of superimposing toner images of four colors of yellow (hereinafter, Y), magenta (hereinafter, M), cyan (hereinafter, C), and black (hereinafter, K) without shifting. There is. Basically, the writing timing of each color is adjusted based on a reference image writing timing signal to create a good image without color shift. However, in practice, the transfer belt 333 (also referred to as a paper transport belt) expands and contracts due to environmental conditions, the degree of durability, and the like.
[0003]
As a solution to this, there is an automatic registration adjustment mechanism. The automatic 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 image writing timing. It is to multiply.
[0004]
[Problems to be solved by the invention]
However, the auto-registration adjustment mechanism needs to perform adjustment every predetermined number of sheets, and when a predetermined value is reached during a job, the job is interrupted and the adjustment mechanism is performed, thereby causing a problem that productivity is reduced. In particular, for a user who needs to print a large number of jobs in a short time, interruption of the job must be avoided as much as possible.
[0005]
[Means for Solving the Problems]
The present invention has been made in view of the above circumstances, and the invention according to claim 1 is an image forming unit that forms a black-and-white or color image on a sheet, and the image forming unit forms a color image on a sheet. Determining means for determining the number of times; and control means for performing a color-specific maintenance operation, wherein the control means controls a timing at which the color-specific maintenance operation is performed in accordance with the value determined by the determination means. It is characterized by doing.
[0006]
The invention according to claim 10 is a program for performing a maintenance operation on an image forming apparatus having an image forming unit for forming a black-and-white or color image on a sheet, wherein the image forming unit stores a color image on a sheet. It is characterized by causing the arithmetic unit to execute a determination procedure for determining the number of times of formation and a control procedure for performing a color-specific maintenance operation in accordance with the value determined by the determination procedure.
[0007]
The invention according to claim 11 is a control device for controlling the timing of performing a maintenance operation on an image forming apparatus having an image forming unit for forming a black and white or color image on a sheet, wherein the image forming unit is Determining means for determining the number of times a color image has been formed on a sheet, and control means for performing a color-specific maintenance operation, wherein the control means determines the number of times the color-specific image is formed on the sheet in accordance with the value determined by the determining means. The timing of performing the maintenance operation is controlled.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
First, a general 4-drum color image forming apparatus will be described with reference to FIG. 101 is a CCD, 311 is a substrate on which the CCD 101 is mounted, 312 is an image processing unit, 301 is a platen glass, 302 is a document feeder (DF) (a mirror surface (not shown) is used instead of the document feeder 302). A light source (halogen lamp or fluorescent lamp) for illuminating the original; 305 and 306 umbrellas for condensing the light of the light sources 303 and 304 onto the original; and 307 to 309 mirrors Reference numeral 310 denotes a lens for condensing reflected light or projection light from the original on the CCD 101, reference numeral 314 denotes a carriage that accommodates the halogen lamps 303 and 304, reflectors 305 and 306, and the mirror 307. Reference numeral 315 includes mirrors 308 and 309. A carriage 313 is an interface (I / F) unit with another IPU or the like. Note that the carriage 314 is moved at a speed V and the carriage 315 is moved at a speed V / 2 mechanically in the 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 structures are the same, the Y image forming unit 317 will be described in detail. The description of the units is omitted. In the Y image forming unit 317, reference numeral 342 denotes a photosensitive drum, on which a latent image is formed 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 device 322 develops the latent image on the photosensitive drum 342 to form a toner image. Note that the developing device 322 includes a sleeve 345 for applying a developing bias to perform development. Reference numeral 323 denotes transfer belt electricity, which discharges from the back of the transfer belt 333 to transfer the toner image on the photosensitive drum 342 to recording paper on the transfer belt 333. The remaining toner that cannot be transferred is collected in the cleaner section 360 by the cleaner blade 361.
[0010]
Next, a procedure for forming an image on a recording sheet will be described. The recording paper and the like stored in the cassettes 340 and 341 are supplied onto the transfer belt 333 by sheet feed rollers 336 and 337 one by one by pickup rollers 338 and 339. The fed recording paper is charged by the adsorption charger 346. Reference numeral 348 denotes a transfer belt roller which drives the transfer belt 333 and charges the recording paper or the like in a pair with the attraction charger 346 to attract the recording paper or the like to the transfer belt 333. A paper edge sensor 347 detects the edge of the 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 a toner image is formed on the surface of the image forming units 317 to 320 in the order of YMCK. The recording paper or the like that has passed through the K image forming unit 320 is separated from the transfer belt 333 after the charge is removed by the charge removing charger 349 to facilitate separation from the transfer belt 333. Reference numeral 350 denotes a peeling charger, which prevents image disturbance due to peeling discharge when recording paper or the like is separated from the transfer belt 333. The separated recording paper and the like are charged by pre-fixing chargers 351 and 352 in order to compensate for the toner adsorption force and prevent image disturbance, and then heat-fixed by the fixing device 334 to the toner image 335. 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 configured to output four colors by adjusting the difference in the distance between the paper leading edge sensor and each image forming unit by delay processing based on the paper leading edge signal from the paper leading edge sensor 347. It is possible to print at a predetermined position.
[0013]
Next, black band adjustment will be described as an example of a common maintenance operation performed for each predetermined value in both black and white and color regardless of a black-and-white job and a color job. The black belt adjustment is performed periodically to prevent the cleaner blade 361, which is in contact with the transfer belt 333 after passing a predetermined number of sheets, from being turned up due to an increase in frictional force with the transfer belt 333. In the paper passing state, a small amount of toner is transferred on the transfer belt 333 in a belt shape in a direction perpendicular to the rotation direction of the transfer belt 333 using the K toner. As a result, the frictional force between the cleaner blade 361 and the transfer belt 333 is reduced, and the turned-up cleaner blade 361 returns to its original state by itself. As described above, the black belt adjustment is a maintenance operation for preventing the cleaner blade 361 from being turned up.
[0014]
Next, similarly to the black band adjustment, the density adjustment will be described as an example of a common maintenance operation performed for each predetermined value in both black and white and color regardless of the black and white job and the color job. The density adjustment is to adjust the density of an image to be formed to be 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. The density is determined by detecting the density of the formed image by the sensor 399, and the density for forming the image is adjusted.
[0015]
Next, the automatic 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 automatic registration adjustment techniques, a specific mark 398 is printed on the transfer belt 333 by, for example, the K image forming unit 320, and a sensor 399 that detects the specific mark 398 is obtained by rotating the transfer belt 333 one or more turns. From the output, the expansion and contraction of the transfer belt 333 is calculated. If the calculation result is longer than the reference value, for example, it is understood that the transfer belt 333 is stretched. At the time of the next image formation, the transfer belt 333 is stretched by the length of the first Y image forming unit 317. By performing control to delay the image forming timing of each of the image forming units 318 to 320 of the MCK with respect to the image forming timing (in this case, the light emission timing of the LED 210), control is performed to maintain the overlay accuracy of the four colors. I have. Therefore, when the automatic registration adjustment is performed, the rotation (one or more rounds) for detecting the expansion and contraction of the transfer belt 333 is required as described above, and the job is interrupted.
[0016]
Control in the conventional automatic registration adjustment will be described with reference to the flowchart of FIG. Conventionally, the storage unit 403 has a counter 415 that counts the total number of images formed irrespective of color / black and white, and stores a set value α indicating a timing when performing the automatic registration adjustment.
[0017]
First, 1 is added to the counter 415 (S110), and the comparing unit 405 determines whether the value of the counter is equal to or larger than the set value α stored in the storage unit 416 (S111). When the value of the counter is equal to or larger than the set value α, the automatic registration adjustment is performed by the adjustment control unit 406 (S112), and the image forming operation is performed by the image forming control unit 404 (S113). If it is determined in S111 that the value of the counter is smaller than α, the image is formed without performing the automatic registration adjustment (S113). When the image formation is completed in S113, it is determined whether or not the job has been completed (S114). If the job has been completed, the flowchart ends. If the job has not ended in S114, the process returns to S110.
[0018]
FIG. 4 is a block diagram of the color image forming apparatus according to the embodiment of the present invention. As shown in FIG. 4, a black-and-white counter 401 and a color counter 402 are separately provided, a set value α indicating a timing for performing a maintenance operation (auto registration adjustment) unique to a color job, a maintenance operation common to a color job and a monochrome job (black). A set value β indicating the timing of performing band adjustment and density adjustment) is stored in the storage unit 403 such as a backup memory in advance. The image forming apparatus further includes an adjustment control unit 406 that performs maintenance operations such as an automatic registration adjustment and a black band adjustment, and an image formation control unit 404 that controls an image forming operation. 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 operation of the CPU 420. .
[0019]
[First Embodiment]
In the first embodiment, a total counter 400 is provided to count the total number of color and black and white image formations in the same manner as the counter 415 described above. In the following description, the automatic registration adjustment will be described as an example of the maintenance operation unique to color, and the black band adjustment will be described as an example of the maintenance operation common to color and black and white.
[0020]
The control of the color image forming apparatus 410 according to the first embodiment is shown in the flowchart of FIG. First, the total counter 400 is incremented by 1 (S100). Next, it is determined whether the identification result from the image reading device 407 (for example, a reader) for identifying a monochrome job or a color job is color or monochrome (S101). If it is determined that the color is black and white, it is determined whether the value of the total counter 400 is equal to or greater than the set value β stored in the storage unit 403 (S102). In S102, when it is determined that the value of the total counter 400 is equal to or more than the set value β, black band adjustment is performed (S103), the total counter 400 is reset (cleared to zero) (S104), and an image is formed on a sheet (S105). ). If it is determined in S102 that the value of the total counter 400 is less than the set value β, the image is formed on the sheet without performing the black band adjustment (S105). When an image is formed on one sheet in S105, it is determined whether or not the job has been completed (S106). If the job has been completed, the flowchart ends. If the job has not been completed in S106, the process returns to S100 to continue the process to form an image on the next sheet.
[0021]
If it is determined in S101 that the color is a color, 1 is added to the color counter 402 (S107), and it is determined whether the value of the color counter 402 is equal to or greater than the set value α (S108). If the value is smaller than the set value α, the process proceeds to S102. If the value is equal to or larger than the set value α, the automatic registration adjustment is performed (S109), the color counter is reset (cleared to zero) (S110), and the process proceeds to S102.
[0022]
When a large number of jobs are performed in the black-and-white mode, a maintenance operation (auto registration adjustment) unique to a color job performed for each predetermined number of sheets is not performed. That is, since interruption of the monochrome job is prevented, the productivity of the monochrome job can be improved.
[0023]
Next, actual effects will be described with reference to FIGS. 6 to 9, the setting value α for performing the maintenance operation (auto registration adjustment) unique to the color job is set to 200 sheets. FIG. 6 shows control according to the prior art. The job settings are set to 250 sheets for monochrome jobs and 50 sheets for color jobs. In the related art, 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, in FIG. 7 according to the first embodiment, even if the number of black-and-white images exceeds 200, the maintenance operation is not performed until the value of the color counter 402 reaches 200. No delay t1 occurs in time.
[0025]
FIG. 8 shows a conventional technique in a setting including a maintenance operation unique to a color job (auto registration adjustment) and a maintenance operation common to a color job and a monochrome job (black band adjustment). In the job setting of FIG. 8, the black-and-white job is 250 sheets and the color job is 150 sheets. In the prior art, when the total counter 400 reaches 150 sheets, black band adjustment is performed, and when the counter further advances and reaches 200 sheets, automatic registration adjustment (described as register adjustment in the figure) is performed. Similarly, when the number of counters reaches 300, black band adjustment is performed, and when the number of counters reaches 400, automatic registration adjustment is performed. Therefore, the total job end delay time is t2a = t1 + 2t2.
[0026]
On the other hand, in FIG. 9 according to the first embodiment, even when the number of black and white images exceeds 200, the maintenance operation is not performed until the color counter 402 reaches 200 sheets. Is performed every time the value of the total counter 400 representing the total number of black and white and color images formed reaches 150, so that the job end delay time is t2b = 2t2, and as a result t2a> t2b, the job end time is reduced (production Improvement).
[0027]
[Second embodiment]
FIG. 10 is a flowchart showing the control according to 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 of the above-described first embodiment, and a description thereof will be omitted.
[0028]
First, it is determined whether the result of identification by the 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 a sheet (S122). When the image formation is completed, it is determined whether or not the job is completed (S123), and if not, the process returns to S120. If it is determined in S123 that the job has been completed, it is determined whether the value of the monochrome counter 401 is equal to or greater than the set value α stored in the storage unit 403 (S124). If the value of the monochrome counter 401 is equal to or more than α, the automatic registration adjustment is performed (S129), the value of the monochrome counter 401 is reset (cleared to zero) (S130), and the flowchart ends. If the value of the monochrome counter 401 is less than α in S124, the flow chart ends without performing the automatic registration adjustment.
[0029]
If it is determined in step S120 that the result of the image reading device 407 for identifying 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 equal to or larger than the set value α stored in the storage unit 403 (S126). If the value of the color counter 402 is equal to or more than the set value α, the automatic registration adjustment is performed (S127), the value of the color counter 402 is reset (cleared to zero) (S128), and the process proceeds to the above-described S123. If the value of the color counter 402 is smaller than the set value α in S126, the process proceeds to S123 without performing the automatic registration adjustment.
[0030]
As described above, in the present embodiment, even after a large number of black-and-white jobs are performed, the value of the black-and-white counter 401 is compared with the set value α, so that a maintenance operation unique to the color job (automatic registration adjustment) can be performed during idle time. And the productivity of the black-and-white job can be prevented 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 set to 200 sheets. FIG. 6 shows control according to the prior art. The job settings are set to 250 sheets for monochrome jobs and 50 sheets for color jobs. In the related art, 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, in FIG. 10 of the present embodiment, the black-and-white job and the color job are counted by different counters, and even if the black-and-white counter 401 exceeds 200, the maintenance operation is performed until the color counter 402 reaches 200. Therefore, the delay t1 does not occur at the end time of the job. Then, the black-and-white counter 401 is compared with the set value α, and the set value α = 200 <the black-and-white counter value = 250, so that the automatic registration adjustment is performed during the idle time after the completion of all jobs. Thereby, it is possible to prevent the productivity of the black-and-white job from decreasing.
[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 in the first embodiment described above, and a description thereof will be omitted.
[0033]
First, it is determined whether the result of identification by the image reading device 407 (for example, a reader) for identifying a monochrome job or a color job is color or monochrome (S131). If it is monochrome, the value of the monochrome counter 401 is incremented by 1 (S132), and an image is formed on a sheet (S133). When the image formation is completed, it is determined whether or not the job has been completed (S134), and if not, the process returns to S131. If it is determined in S134 that the job has been completed, it is determined whether the next job is in color (S135). If the next job is a color job, it is determined whether the black-and-white counter 401 is equal to or greater than α (S136). If it is equal to or greater than α, automatic registration adjustment is performed (S141), and the monochrome counter 401 is reset (cleared to zero). (S142), and the flowchart ends. If it is determined in step S135 that the next job is not color, or if the monochrome counter 401 is smaller than α in step S136, the flowchart ends without performing the automatic registration adjustment.
[0034]
If it is determined in step S131 that the result of the image reading device 407 for identifying 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 the color counter 402 is equal to or larger than the set value α stored in the storage unit 403 (S138). If the value of the color counter 402 is equal to or greater than the set value α, the automatic registration adjustment is performed (S139), the color counter 402 is reset (cleared to zero) (S140), and the process proceeds to S133 described above. If the value of the color counter 402 is smaller than the set value α in S138, the process proceeds to S133 without performing the automatic registration adjustment.
[0035]
In the case where the current job is a black-and-white job and the next job is a color job, at least interrupting the current job by executing a maintenance operation specific to the color job after the current job is completed. As a result, the productivity of the black-and-white job can be prevented from being reduced.
[0036]
Next, an actual effect 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 set to 200 sheets. FIG. 13 shows control according to the conventional technique. The job settings are 250 sheets for the current black-and-white job and 50 sheets for the reserved job as a color job. In the related art, the maintenance operation is performed when the counter reaches 200 sheets. Therefore, the end time of the job is delayed by t3 time compared to the case where the maintenance operation is not performed. On the other hand, in FIG. 14 of the present embodiment, the monochrome job and the color job are counted by different counters, and even if the monochrome counter 401 exceeds 200, the maintenance operation is performed until the color counter 402 reaches 200. 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, by performing a maintenance operation (auto registration adjustment) specific to the color job after the current job is completed, at least the current job can be completed without interruption. Can be prevented from decreasing (equivalent to t3).
[0037]
In the above description, the case where the reader (image reading device 407) is mounted as the image input means has been described, but this is the personal computer (PC) 409 connected to the color image forming apparatus 410 via the network controller 408. However, by transmitting information indicating whether the job is a black-and-white job or a color job from the personal computer (PC) 409, it is possible to identify whether the job is black-and-white or color. it can.
[0038]
Further, if there are a plurality of job counters, the present invention is not limited to the monochrome counter 401 and the color counter 402. For example, a combination of the total counter 400 and the color counter 402 or a combination of the total counter 400 and the monochrome counter 401 can be implemented by slightly changing the configuration.
[0039]
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, one controller may determine the number of times a color image has been formed on a sheet, perform a maintenance operation unique to a color, or control the timing of the maintenance operation.
[0041]
【The invention's effect】
As described above, according to the first aspect of the invention, the control unit controls the timing of performing the color-specific maintenance operation in accordance with the value determined by the determination unit. It is possible to prevent interruption of the image forming operation due to the maintenance operation unique to the color.
[0042]
Further, according to the second aspect of the present invention, it is possible to execute the adjustment for preventing the color shift for each color component occurring when a color image is formed on a sheet at an appropriate timing.
[0043]
According to the third aspect of the present invention, the second control means controls the timing of performing the maintenance operation common to color and black and white in accordance with the number of times the image forming means has formed an image on the sheet. The maintenance operation unique to color can be performed at the appropriate timing according to the number of times the sheet is formed on the sheet, and the maintenance operation common to color and black and white is performed at the appropriate timing according to the total value of the number of color and black and white image formation Can be.
[0044]
Also, in the inventions of claims 4 to 8, the same effects as those of claim 1 can be obtained.
[0045]
According to the ninth aspect of the present invention, since the storage means for storing the set value indicating the timing at which the maintenance operation is performed by the control means, the preferred timing for performing the adjustment by the adjustment means is stored in advance in the storage means. There is an effect that can be kept.
[0046]
Also, in the inventions of claims 10 and 11, the same effects as those of claim 1 can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating 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 illustrating control in a conventional automatic registration adjustment.
FIG. 4 is a diagram illustrating a block diagram of the color image forming apparatus of the present invention.
FIG. 5 is a flowchart illustrating control of the color image forming apparatus according to 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
FIG. 9 is a diagram illustrating a timing at which an automatic registration adjustment and a black belt adjustment in the related art are interrupted.
FIG. 9 is a diagram illustrating timings at which an automatic registration adjustment and a black band adjustment are interrupted 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 control unit
405 Comparison section
406 Adjustment control unit
407 Image reading unit
410 Color Image Forming Apparatus

Claims (11)

Image forming means for forming a black and white or color image on the sheet,
Determining means for determining the number of times the image forming means has formed a color image on a sheet,
Control means for performing a color-specific maintenance operation,
The image forming apparatus according to claim 1, wherein the control unit controls a timing at which the color-specific maintenance operation is performed according to the value determined by the determination unit. The image forming apparatus according to claim 1, wherein the color-specific maintenance operation is an adjustment operation for preventing a color shift for each color component that occurs when a color image is formed on a sheet. A second control unit that performs a maintenance operation common to color and black and white;
2. The image forming apparatus according to claim 1, wherein the second control unit controls a timing at which the maintenance operation common to the color and the black and white is performed according to the number of times the image forming unit forms an image on a sheet. . Conveying means for conveying a sheet so that the image forming means forms an image,
Having a cleaner blade arranged to be in contact with the transporting means,
4. The image forming apparatus according to claim 3, wherein the maintenance operation common to the color and the black and white is an operation for preventing the cleaner blade from being turned up by friction with the conveyance unit. 5. 4. The image forming apparatus according to claim 3, wherein the maintenance operation common to color and black and white is an operation of detecting the density of toner for forming an image by the image forming unit. 2. The image forming apparatus according to claim 1, wherein the control unit performs the color-specific maintenance operation after a black-and-white job is completed. 7. The image forming apparatus according to claim 6, wherein the control unit causes the color-specific maintenance operation to be performed when the next job is a color job. The image to be formed on the sheet by the image forming means, identification means for identifying whether a black and white image or a color image,
The image forming apparatus according to claim 1, wherein the determining unit counts the number of times that the image forming unit has formed a color image on a sheet based on the identification result of the identifying unit. 2. The image forming apparatus according to claim 1, further comprising a storage unit configured to store a set value indicating a timing at which the maintenance operation is performed by the control unit. A program for performing a maintenance operation on an image forming apparatus having an image forming unit that forms a monochrome or color image on a sheet,
A determining step of determining the number of times the image forming unit has formed a color image on a sheet,
A program for causing an arithmetic unit to execute a control procedure for performing a color-specific maintenance operation according to the value determined by the determination procedure. A control device for controlling a timing of 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,
Determining means for determining the number of times the image forming means has formed a color image on a sheet,
Control means for performing a color-specific maintenance operation,
The control device controls the timing at which the color-specific maintenance operation is performed in accordance with the value determined by the determination unit.

Images