JP2008233410A - Image forming apparatus, image forming method, computer program, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress toner consumption to the utmost when forming a toner mark pattern used for control of positional deviation correction. <P>SOLUTION: Whether color shift correction succeeds continuously by fixed number of times is checked (102). When it succeeds continuously (102-Yes), a toner pattern that is a toner mark pattern for correction whose width is made smaller than an initial value is formed next and succeeding times (103), and the pattern width made smaller is stored to be used as a set value for next and succeeding times (104), and then processing is finished. When the color shift correction control continuously succeeds by fixed number of times next, therefore, the pattern is made a pattern whose width is much smaller. On the other hand, when color shift correction fails even once (102-No), the pattern width is made larger than the initial value (105), to perform the correction again (106), and the pattern width is made larger until the correction succeeds. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copy, a printer, or a facsimile, and more particularly to an image forming apparatus suitable for a tandem type color image forming apparatus having a transfer belt, a laser driving device, and a photoconductor for each color. The present invention relates to a forming method, a computer program for executing the image forming method on a computer, and a storage medium storing the computer program.

  2. Description of the Related Art So-called tandem color image forming apparatuses that use a plurality of photoconductors and transfer a single image onto a transfer belt to form a full color image are known. In this type of color image forming apparatus, a toner mark pattern is drawn on a transfer belt, and color misregistration correction processing and toner density detection are performed. For example, the inventions disclosed in Patent Documents 1 and 2 are known.

  Among these, in Patent Document 1, any or all of the sensors arranged in the main scanning direction are caused to read the toner density pattern generated by the timing pattern generation circuit for each color, the deviation is detected from the target density, and the density is lowered. If so, the toner in the corresponding color developer is replenished, thereby suppressing the occurrence of color misregistration, and without waiting for the user to form a high-quality image with a stable toner density. An invention is disclosed in which detection / correction can be performed in the shortest time.

Also, in Patent Document 2, a large registration mark is used when detecting the first misregistration amount immediately after power-on, and a small registration mark is used when detecting other misregistration amounts. In addition, the registration position of the small registration mark on the photosensitive drum is corrected by the amount of deviation from the detection line of the large registration mark, and color misregistration correction is reliably performed while minimizing toner consumption associated with registration mark formation. An invention that can be made is disclosed.
JP 2006-084579 A JP 2000-664632 A

  As described in each of the above patent documents, in a tandem type color image forming apparatus having a transfer belt, a toner mark pattern is formed on the transfer belt, the toner mark pattern is detected, and color shift is detected by the detection output. Correction processing is performed. However, since a toner mark pattern is drawn, a certain amount of toner is always consumed. Therefore, in Patent Document 2, in order to prevent toner consumption, the size of the V-shaped pattern (dimension in the line extending direction) is changed, but the width of this pattern is not considered.

  Therefore, a problem to be solved by the present invention is to make it possible to suppress toner consumption as much as possible with respect to the width of the toner mark pattern used for misregistration correction control.

  In order to solve the above-mentioned problem, the first means detects the color misregistration correction toner mark pattern, performs color misregistration correction, and forms a color image by superimposing a plurality of color images. Means is provided for narrowing the pattern width of the misregistration correction toner pattern in the sub-scanning direction to a minimum width capable of color misregistration correction processing.

  According to a second means, in the first means, when the thinning means acquires correction data and performs color misregistration correction, the color misregistration is performed a predetermined number of times with a set width having a pattern width in the sub-scanning direction. When the correction control is successful, the pattern width in the sub-scanning direction is set to a preset one-step narrow width.

  According to a third means, in the first means, when the thinning means acquires the correction data and performs the color misregistration correction, the color misregistration correction control is performed with a set width having a pattern width in the sub-scanning direction. If this fails, the pattern width in the sub-scanning direction is formed with a one-step thick width.

According to a fourth aspect, in the second or third means, when the pattern width in the sub-scanning direction has a set width and the color shift correction control has failed for a set number of times, the pattern width is changed to the color shift. The fifth means is the pattern in the sub-scanning direction in the second or third means, wherein the lower limit width of the correction toner mark pattern width is set, and no toner mark pattern less than the lower limit width is formed thereafter. If the width of the pattern is set to a certain level and the color misregistration correction control fails more than the set percentage, the pattern width is set as the lower limit width of the color misregistration correction toner mark pattern. A pattern is not formed.

  The sixth means forms the pattern width in the sub-scanning direction with one step thick when the color misregistration correction control fails in the second or third means, and when the upper limit is reached, the pattern width is increased. It is formed by an upper limit value.

  According to a seventh means, in the sixth means, if the color misregistration correction continues despite the fact that the pattern width in the sub-scanning direction has reached the upper limit value, the color misregistration correction is stopped and the toner consumption is reduced thereafter. It is characterized in that processing for suppressing or processing for causing a machine to malfunction is executed.

  The eighth means is characterized in that, in the seventh means, there is provided means for setting either processing for suppressing the toner consumption amount or processing for causing the machine to malfunction.

  According to a ninth means, in any one of the first to third means, when the initial value of the width of the correction toner mark pattern is determined at the time of initialization, a pattern which is narrower by a fixed width from the upper limit value of the pattern width of the pattern. , A pattern width that can be recognized therein is obtained, and a pattern width that is widened by a width that does not fail the color misregistration correction control with respect to the pattern width is set as an initial value.

  A tenth means is the ninth means characterized in that the initialization time is any of arrival time, transfer belt replacement, and photoconductor replacement.

  According to an eleventh means, in any one of the first to tenth means, the pattern width in the sub-scanning direction of the color misregistration correction toner mark pattern is set independently for each of a plurality of colors. Features.

  A twelfth means is characterized in that, in the eleventh means, the plurality of colors are black, yellow, magenta and cyan.

  A thirteenth means is characterized in that, in any one of the first to twelfth means, a toner mark sensor for detecting the color misregistration correction toner pattern is provided.

  A fourteenth means is characterized in that, in the thirteenth means, the color misregistration correction toner pattern comprises a plurality of rows of patterns extending in the sub-scanning direction from a plurality of positions in the main scanning direction.

  A fifteenth means is characterized in that, in the thirteenth means, a non-volatile memory for holding pattern width data from the toner mark sensor obtained by reading a pattern width of the color misregistration correction toner mark pattern is provided.

  The sixteenth means is characterized in that, in any of the first to fifteenth means, the pattern width of the color misregistration correction toner mark pattern is set by the number of scanning lines in the sub-scanning direction.

  The seventeenth means is characterized in that, in any one of the first to fifteenth means, the distance from the writing position of the color misregistration correction toner mark pattern to the writing position of the next pattern is constant regardless of the pattern width. And

  According to an eighteenth means, in any one of the first to seventeenth means, when the color misregistration correction toner mark pattern forms a color image by superimposing a plurality of color images, the image is temporarily transferred. It is formed on an intermediate transfer medium.

  According to a nineteenth means, in any one of the first to seventeenth means, when the color misregistration correction toner mark pattern overlaps a plurality of color images to form a color image, the sheet recording medium is adsorbed. It is formed on a conveyance belt that conveys and transfers an image to the sheet-like recording medium.

  A twentieth means is an image forming method for detecting a color misregistration correction toner mark pattern to perform color misregistration correction and superimposing a plurality of color images to form a color image. The pattern width in the scanning direction is narrowed to a minimum width that allows color misregistration correction processing.

  In the twenty-first means, when the correction data is acquired and the color misregistration correction is performed in the twentieth means, when the color misregistration correction control is successful a certain number of times with a set width having a pattern width in the sub-scanning direction. If the pattern width in the sub-scanning direction is set to a preset one-step narrow width, and the color misregistration correction control fails with a predetermined width in the sub-scanning direction, the pattern width in the sub-scanning direction is reduced by one. It is characterized in that the pattern is formed by setting a step-wide width.

  The twenty-second means is characterized by a computer program comprising a procedure for causing a computer to execute the image forming method according to the twentieth or twenty-first means.

  The twenty-third means is characterized in that the computer program according to the twenty-second means is stored in the storage means so that the computer can read and execute it.

  According to the present invention, since the pattern width in the sub-scanning direction of the color misregistration correction toner pattern is reduced to the minimum width that allows color misregistration correction processing, the width of the toner mark pattern used for misregistration correction control is reduced. Concerning the formation, toner consumption can be suppressed as much as possible.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing an outline of a main part of a color image forming apparatus according to an embodiment of the present invention. In FIG. 1, the color image forming apparatus includes a system control unit 1, ROM 2, nonvolatile RAM 3, LD writing circuit 4, toner mark (TM) sensor 5, transfer belt 6, and image forming element 10. The image forming element is a tandem color image forming element, and is a photoreceptor 10Y, 10C, 10M, or 10K (hereinafter generally indicated by reference numeral 10), and a charging unit (not shown) provided on the outer periphery of each photoreceptor. , A developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit.

  The system control unit 1 performs control related to measurement data processing and color misregistration correction by the TM sensor 5. The ROM 2 stores a program, and the nonvolatile RAM 3 stores color misregistration correction data and the like. The LD writing circuit 4 is a circuit that generates a laser for irradiating the photoconductor 10. The TM sensor 5 is a light reflection type sensor used for measuring the distance between toner mark patterns. In the configuration of FIG. 1, the surface of each photoconductor 10 is charged by a charging unit, and an LD (not shown) is caused to emit light by an LD writing circuit 4 on the charged surface of each photoconductor 10 to perform optical writing to form a latent image. . The latent image is developed with toner for each color by the developing unit, and the visualized toner image is transferred to the transfer belt 6 to form a full-color image.

  FIG. 2 is a diagram showing a state of a toner mark pattern visualized with the configuration of FIG. Here, the order in which the toner mark patterns are drawn is yellow (Y), black (K), cyan (C), and magenta (M). First, as shown in FIG. 2A, a color misregistration correction toner mark pattern is drawn with a preset width during color misregistration correction. The pattern of the set width is read by the TM sensor 5, and the positional deviation correction control is executed by the system control unit 1 based on the output of the TM sensor 5. Since the misregistration correction control itself is a known technique as disclosed in the above-described conventional example, it is not particularly described here. If the color misregistration correction control is successful for a certain number of times, the pattern is drawn with a narrow width by one step as shown in FIG. If the color misregistration correction control fails for the pattern shown in FIG. 2A, the pattern is drawn with a thick width as shown in FIG. 2C, and correction control is performed. The term “successful color misregistration correction control” refers to the case where it is not necessary to perform correction when the misregistration correction amount is corrected as an initial value after the toner mark pattern is read and the misregistration correction control is executed. Pointing.

  FIG. 3 is a flowchart illustrating a processing procedure in the first embodiment. In this embodiment, the pattern width as shown in FIG. 2 is changed depending on whether the color misregistration correction control is successful or unsuccessful. This control is executed by the system control unit 1.

  In FIG. 3, when this process is started (step 101), it is first checked whether or not the color misregistration correction has succeeded for a certain number of times (step 102). If it succeeds continuously (step 102 -Yes), a toner pattern in which the width of the correction toner mark pattern is narrowed from the initial value is formed from the next time (step 103), and the narrowed pattern width is set to the set value from the next time. Is stored for use (step 104), and the process ends. Therefore, if the next color misregistration correction control is succeeded for a certain number of times, the pattern becomes thinner.

  On the other hand, if the color misregistration correction has failed even once in step 102 (step 102-No), the pattern width is made thicker than the initial value (step 105), correction is performed again (step 106), and the pattern width is successful. To make it thicker.

  That is, in this embodiment, when a color misregistration correction toner mark pattern is drawn on the transfer belt, and correction data is acquired and color misregistration correction is performed, the pattern width in the sub-scanning direction of the color misregistration correction toner mark pattern is obtained. Is made as thin as possible (if steps 102 → 103 → 104 are repeated, it becomes gradually thinner). At that time, if the color misalignment correction control is successful a certain number of times with a certain width in the sub-scanning direction, the pattern width in the sub-scanning direction is drawn with a narrow width (step 103). If the color misregistration correction control fails with a certain pattern width, the pattern width in the sub-scanning direction is drawn with a one-step thick width (step 105).

  As described above, if the color misregistration correction control is successful a certain number of times, the color misregistration correction toner mark pattern becomes gradually thinner, and the toner consumption for drawing the color misregistration correction toner mark pattern can be suppressed. As described above, according to this embodiment, the pattern width in the sub-scanning direction of the color misregistration correction toner mark pattern can be made as narrow as possible, so that it is possible to suppress the amount of toner consumed to draw the color misregistration correction toner mark pattern.

  In addition, when the color misregistration correction control is successful a predetermined number of times, the pattern width in the sub-scanning direction is drawn with a narrow width, so that it is possible to suppress the toner consumption for drawing the color misregistration correcting toner mark pattern.

  In addition, when the color misregistration correction control fails, the pattern width in the sub-scanning direction is drawn with a one-step thick width. Therefore, when the correction control fails, the pattern width can be increased and correction control can be performed again.

  FIG. 4 is a flowchart illustrating a processing procedure in the second embodiment. In this embodiment, when the correction data is acquired and the color misregistration correction is performed, if the pattern width in the sub-scanning direction has a set width and the color misregistration correction control fails for the set number of times, the pattern is detected. The width is set as the lower limit width of the color misregistration correction toner mark pattern, and a toner mark pattern having a width equal to or smaller than the lower limit width is not drawn in the future.

  That is, in FIG. 4, when the correction process is started (step 111), the set pattern width is set to L, and when the color misregistration correction control fails with the pattern width L (step 112-No), the pattern width L is set. The number of failures is counted (step 113), and if the number of failures is equal to or greater than the set number (step 114), the pattern width L is set as the lower limit (step 115), and correction is not performed below the pattern width L (step 115). 116), the process is finished (step 117).

  In this way, when the pattern width in the sub-scanning direction has a set width and the color misregistration correction control has failed for the set number of times, the pattern width is set as the lower limit width of the color misregistration correction toner mark pattern, and in the future Since the toner mark pattern below the lower limit width is not drawn, it is possible to prevent the control with the pattern width that is highly likely to fail the color misregistration correction control.

  FIG. 5 is a flowchart illustrating a processing procedure according to the third embodiment. In this embodiment, when performing color misregistration correction by obtaining correction data, if the color misregistration correction control fails more than a set ratio, the pattern width is set to the lower limit of the width of the toner mark pattern for color misregistration correction. The width is set so that a toner mark pattern below the lower limit width will not be drawn in the future.

  That is, in FIG. 5, when the correction process is started (step 121), the set pattern width is set to L, and when the color misregistration correction control fails at the pattern width L (step 122-No), the set n is set. After the correction is performed more than once, the ratio of failure with the pattern width L is calculated (step 123). When the ratio of failure is equal to or greater than the set ratio (step 124), the pattern width L is set as the lower limit (step 125). If the width is equal to or smaller than the width L, correction is not performed (step 126), and the process ends (step 127).

  In this way, when the pattern width in the sub-scanning direction has a set width and the color misregistration correction control fails more than a set ratio, the pattern width is set as the lower limit width of the color misregistration correction toner mark pattern, Since the toner mark pattern below the lower limit width will not be drawn in the future, it is possible to prevent the control with the pattern width that is highly likely to cause the color misregistration correction control to fail.

  FIG. 6 is a flowchart illustrating a processing procedure according to the fourth embodiment. In this embodiment, when the correction data is acquired and the color misregistration correction is performed, if the color misregistration correction control fails with a set width of the pattern width in the sub scanning direction, the pattern width in the sub scanning direction is set. Draw with a thick width, but set an upper limit in advance.If the upper limit is reached even if the pattern width is increased stepwise due to color misregistration correction failure, the pattern width is set to the upper limit. It is what I drew.

  That is, in FIG. 6, when the correction process is started (step 131), the set pattern width is set to L, and when the color misregistration correction control fails at the pattern width L (step 132-No), the pattern width is set to 1. Although the thickness is increased by M (step 133), if M exceeds the set upper limit (step 134-Yes), the pattern width remains L (step 135), and correction control is performed again while maintaining L. Perform (step 136), and the process ends (step 137). When M does not exceed the set upper limit value (step 134 -No), correction control is performed again with the pattern width M (step 137), and the process is ended (step 137).

  In this way, when color misregistration correction control fails with a set width with a pattern width in the sub-scanning direction, the pattern width in the sub-scanning direction is drawn with a one-step thick width, but an upper limit value is set in advance. Even if the pattern width gradually increases due to color misregistration correction failure, if the upper limit is reached, the pattern width is drawn at the upper limit value, so the width of the color misregistration correction control pattern will increase without limit. There can be no. Even in this case, it is premised that the pattern width should be as thin as possible for misregistration correction. Even if the pattern width is thicker than the initial value, the pattern width must be as narrow as possible to allow misregistration correction processing. There is no change.

  FIG. 7 is a flowchart illustrating a processing procedure according to the fifth embodiment. In this embodiment, when the color misregistration correction continues despite the fact that the pattern width in the sub-scanning direction has reached the upper limit value, the process of stopping the color misregistration correction to reduce the toner consumption or the machine as a failure. The processing to be performed is performed.

  That is, in FIG. 7, when the correction process is started (step 141) and the pattern width for color misregistration correction control has already reached the upper limit M (step 142), further color misregistration correction control is set from there. When the number of times (n times) has failed continuously (step 143-Yes), and the setting after the failure of the correspondence at the time of continuous failures n times continuously is to cancel the correction control (step 144-correction stop) Thereafter, the color misregistration correction control is stopped (step 145), the toner consumption is suppressed (step 146), and the correction process is ended (step 148). On the other hand, when the response at the time of continuous failure is set to machine failure (step 144), the processing is ended (step 148) with the machine treated as a failure (step 147).

  If the color misregistration correction continues despite the fact that the pattern width in the sub-scanning direction has reached the upper limit in this way, the process of stopping the color misregistration correction to reduce the toner consumption or the process of causing the machine to malfunction Therefore, it is possible to suppress or reduce the amount of toner consumed to draw the color misregistration correction toner mark pattern.

  FIG. 8 is an explanatory diagram showing a state of pattern formation in the sixth embodiment. In this embodiment, when the initial value of the width of the correction toner mark pattern is determined at the time of initialization, the toner mark pattern is drawn with a narrower width from the upper limit value, and the most appropriate pattern width is set as the initial value. It is what I did.

  In FIG. 8, when determining the initial value of the color misregistration correction control toner mark pattern width at the time of initialization, as shown in the figure, a thin pattern is drawn little by little from each color upper limit value M, and a pattern that can be recognized therein The width is obtained. However, if the minimum recognizable width is set as an initial value, there is a high possibility that the color misregistration correction control will fail, so a slight margin is provided.

  The processing procedure at this time is shown in the flowchart of FIG. In this figure, this process is started (step 151), and at the time of initialization such as arrival, transfer belt replacement, photoconductor replacement (step 152), a thin toner mark pattern is drawn from the upper limit M by a certain width (step 151). 153), the recognizable pattern width is obtained using the TM sensor 5 (step 154). Further, the initial value is determined in consideration of the margin (step 155), the initial value is stored in the nonvolatile RAM (step 156), and the process is terminated.

  In this way, when determining the initial value of the width of the correction toner mark pattern at the time of initialization, the toner mark pattern is drawn by a narrower pattern from the upper limit by a fixed width, so that the most appropriate pattern width (to prevent color misregistration correction from failing) Therefore, the initial width of the color misregistration correction toner mark pattern can be determined at the time of initialization. In addition, since the initialization is performed at the time of arrival, transfer belt replacement, and photoconductor replacement, the timing for performing the initialization process can be set reliably.

  Also, when acquiring correction data and performing color misregistration correction, in order to reduce the amount of toner consumed to draw the color misregistration correction toner mark pattern, the pattern width in the sub-scanning direction of the optimum color misregistration correction toner mark pattern However, since the nonvolatile memory is provided to hold the data, the data can be held when the power is turned off and when the energy is saved.

  FIG. 10 is a diagram for explaining the meaning of correction when the color misregistration correction control described in the first to sixth embodiments is combined. Here, the transition state of the width of the toner mark pattern at the time of correction is shown. First, an initial set value (shown as “initial value” in the figure) is determined, and when success is succeeded (5 times in the example in the figure), the pattern width is reduced by one step, and when the pattern fails, the pattern width is increased. . The number of times set with a certain pattern width or a fixed rate (failed 4 times in the example in the figure) If the color misregistration correction fails, the lower limit value is set, and after that, even if succeeded continuously, the width below the lower limit value is not set .

  Further, if the pattern width becomes thicker at any time due to deterioration of the toner mark sensor with time, there is a possibility that the upper limit value will be reached eventually. However, if the upper limit is continuously failed (five times in the example in the figure), then the color misregistration correction is stopped or the machine failure process is performed.

  FIG. 11 is a view showing a toner mark pattern formation state. In the above-described first to sixth embodiments, processing common to all colors has been described, but it is not necessary to use the same pattern for all color misregistration correction. The width of the toner mark pattern used for each color varies as it is used. Therefore, even when used as an initial value, there is a magnitude of shift in each color in each device. For this reason, the color misregistration correction control pattern width is set with a different width for each color from the stage of setting an initial value as shown in FIG. 11, and the subsequent pattern width also changes independently for each color.

  In this way, the pattern width in the sub-scanning direction of the color misregistration correction toner mark pattern is set for each color of black, yellow, magenta, and cyan, so the toner consumption for drawing the color misregistration correction toner mark pattern for each color Can be suppressed.

  For example, toner mark patterns are often provided at three locations, for example, the front side, the center portion, and the rear side. FIG. 12 is a diagram showing an example of a toner mark pattern provided in three rows of A, B, and C rows on the front, center, and rear sides. The TM sensor 5 is provided in each of the A, B, and C columns, and reads the toner mark pattern for each column. In that case, it is natural that the initial value of the pattern width is different for each pattern of the A column, the B column, and the C column, and the pattern width is changed independently for each color and each column. Of course.

  The setting of the pattern width in the sub-scanning direction of the color misregistration correction toner mark pattern is managed by the number of scanning lines. This management is handled by the system control unit 1.

  When color misregistration correction is performed after setting the color misregistration correction toner mark pattern width in this way, the pattern width differs for each color, but from pattern writing to writing the next color pattern as shown in FIG. It is held at a constant distance regardless of the pattern width. Thereby, the time of color misregistration correction control can be made constant.

  The processing procedures shown in the flowcharts of the first to seventh embodiments are stored in the ROM 2 or stored in a hard disk (not shown) and executed by the CPU of the system control unit 1. The program is downloaded and used via an external storage device such as an FD, a CD-ROM, a card-type storage medium, the Internet, or communication means.

1 is a diagram illustrating an outline of a main part of a color image forming apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a state of a toner mark pattern visualized with the configuration of FIG. 1. 3 is a flowchart illustrating a processing procedure in the first embodiment. 10 is a flowchart illustrating a processing procedure in the second embodiment. 10 is a flowchart illustrating a processing procedure in the third embodiment. 10 is a flowchart illustrating a processing procedure in the fourth embodiment. 10 is a flowchart illustrating a processing procedure in the fifth embodiment. FIG. 10 is an explanatory diagram showing a state of pattern formation in Example 6. 10 is a flowchart illustrating a processing procedure in Embodiment 7. It is a figure for demonstrating the meaning of the correction | amendment in the case of implementing combining the color shift correction control demonstrated in Example 1 thru | or 6. FIG. 6 is a diagram illustrating a formation state of a toner mark pattern in which a width is set for each color. FIG. 6 is a diagram illustrating an example of a toner mark pattern provided in three rows of front, center, and rear A rows, B rows, and C rows. It is a figure which shows the state from the pattern writing to the writing of the pattern of the next color.

Explanation of symbols

1 System controller 2 ROM
3 Nonvolatile RAM
4 LD writing circuit 5 Toner mark (TM) sensor 6 Transfer belt 10 Imaging element

Claims (23)

In an image forming apparatus that detects a color misregistration correction toner mark pattern, corrects color misregistration, and superimposes a plurality of color images to form a color image.
An image forming apparatus comprising: means for narrowing a pattern width of the color misregistration correction toner pattern in a sub-scanning direction to a minimum width capable of performing color misregistration correction processing. The image forming apparatus according to claim 1.
The thinning means obtains correction data and performs color misregistration correction, and if the color misregistration correction control is successful a certain number of times with a predetermined width in the sub scanning direction, the sub scanning direction pattern An image forming apparatus, characterized in that the width is set to a predetermined narrow width. The image forming apparatus according to claim 1.
The thinning means obtains correction data and performs color misregistration correction, and if the color misregistration correction control fails with a set width having a pattern width in the sub scanning direction, the pattern width in the sub scanning direction is set. An image forming apparatus, wherein the image forming apparatus is formed with a one-step thick width. The image forming apparatus according to claim 2 or 3,
When the pattern width in the sub-scanning direction has a set width and the color misregistration correction control has failed for the set number of times, the pattern width is set as the lower limit width of the color misregistration correction toner mark pattern. An image forming apparatus characterized by not forming a toner mark pattern having a width or less. The image forming apparatus according to claim 2 or 3,
When the pattern width in the sub-scanning direction has a set width and the color misregistration correction control fails more than a set ratio, the pattern width is set as the lower limit width of the color misregistration correction toner mark pattern. An image forming apparatus, wherein a toner mark pattern having a width less than the lower limit is not formed. The image forming apparatus according to claim 2 or 3,
An image forming apparatus, wherein when the color misregistration correction control is unsuccessful, the pattern width in the sub-scanning direction is drawn with one step thick, and when the upper limit is reached, the pattern width is formed with the upper limit. The image forming apparatus according to claim 6.
If the color misregistration correction continues despite the fact that the pattern width in the sub-scanning direction has reached the upper limit value, a process for stopping the color misregistration correction to reduce the toner consumption or a process for causing the machine to fail is executed. An image forming apparatus. The image forming apparatus according to claim 7.
An image forming apparatus comprising: means for setting either a process for suppressing the toner consumption or a process for causing the machine to malfunction. The image forming apparatus according to any one of claims 1 to 3,
When determining the initial value of the width of the correction toner mark pattern at the time of initialization, a thin pattern is formed by a fixed width from the upper limit value of the pattern width of the pattern, and a pattern width that can be recognized therein is obtained, and the pattern width is obtained. On the other hand, an image forming apparatus characterized in that an initial value is a pattern width widened by a width at which color misregistration correction control does not fail. The image forming apparatus according to claim 9.
2. An image forming apparatus according to claim 1, wherein the initialization is any of arrival, transfer belt replacement, and photoconductor replacement. The image forming apparatus according to any one of claims 1 to 10,
An image forming apparatus, wherein a pattern width in a sub-scanning direction of the color misregistration correction toner mark pattern is set independently for each of a plurality of colors. The image forming apparatus according to claim 11.
The image forming apparatus according to claim 1, wherein the plurality of colors are black, yellow, magenta, and cyan. The image forming apparatus according to any one of claims 1 to 12,
An image forming apparatus comprising: a toner mark sensor for detecting the color misregistration correction toner pattern. The image forming apparatus according to claim 13.
2. The image forming apparatus according to claim 1, wherein the color misregistration correction toner pattern includes a plurality of rows of patterns extending from a plurality of positions in the main scanning direction to the sub scanning direction. The image forming apparatus according to claim 13.
An image forming apparatus comprising: a non-volatile memory that holds pattern width data from the toner mark sensor that has read the pattern width of the color misregistration correction toner mark pattern. The image forming apparatus according to any one of claims 1 to 15,
An image forming apparatus, wherein a pattern width of the color misregistration correction toner mark pattern is set according to the number of scanning lines in the sub-scanning direction. The image forming apparatus according to any one of claims 1 to 15,
An image forming apparatus, wherein a distance from a writing position of the color misregistration correction toner mark pattern to a writing position of the next pattern is constant regardless of a pattern width. The image forming apparatus according to any one of claims 1 to 17,
An image forming apparatus, wherein the color misregistration correction toner mark pattern is formed on an intermediate transfer medium to which an image is temporarily transferred when a color image is formed by superimposing a plurality of color images. The image forming apparatus according to any one of claims 1 to 17,
The color misregistration correction toner mark pattern is formed on a conveyance belt that adsorbs and conveys a sheet-like recording medium when a color image is formed by superimposing a plurality of color images, and transfers the image to the sheet-like recording medium. An image forming apparatus. In an image forming method of detecting a color misregistration correction toner mark pattern and performing color misregistration correction and superimposing a plurality of color images to form a color image,
An image forming method comprising narrowing a pattern width of the color misregistration correction toner pattern in a sub-scanning direction to a minimum width capable of performing color misregistration correction processing. The image forming method according to claim 20, wherein
When the correction data is acquired and the color misregistration correction is performed, if the color misregistration correction control is successful a certain number of times with a certain width in the sub scanning direction, the pattern width in the sub scanning direction is set in advance. If the color misalignment correction control fails with a set width that is one step narrower and the pattern width in the sub-scanning direction is set, the pattern width is set by setting the pattern width in the sub-scanning direction one step thicker. It is characterized by.   A computer program comprising a procedure for causing a computer to execute the image forming method according to claim 20 or 21.   23. A storage medium in which the computer program according to claim 22 is stored so that the computer can read and execute the computer program.

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