JP2018010244A - Image forming apparatus and image formation control program - Google Patents

Abstract

Proper color registration adjustment is performed without stopping an image forming operation being executed.
An image forming unit for forming an image by transferring an image formed on an image carrier using a plurality of color materials onto a sheet, and one of the plurality of colors as a reference color. A control unit having a function of performing registration adjustment for adjusting an image formation position by a color material of another color with respect to an image formation position by a color material of a color, wherein the control unit includes a plurality of control units Any of the first resist adjustment for adjusting based on the first pattern corresponding to the inspection item and the second resist adjustment for adjusting based on the second pattern corresponding to the inspection item fewer than the first resist adjustment. The image forming unit is controlled to perform the second registration adjustment without interrupting the image forming operation being executed.
[Selection] Figure 1

Description

  The present invention relates to an image forming apparatus such as a copying machine or a printer and an image forming control program, and more particularly to an image forming apparatus having a registration adjustment function and an image forming control program.

  As an image forming apparatus, an image carrier such as a photosensitive drum or a photosensitive belt is driven in the sub-scanning direction, and exposure by scanning (main scanning) for one line or a plurality of lines in the main scanning direction according to image data is performed. It is known that two-dimensional (every page) image formation is performed by repeating.

  The color image forming apparatus uses color materials of a plurality of colors (for example, ink and toner, in this specification, “toner” is used as a specific example of the color material in the electrophotographic image forming apparatus). It is necessary to accurately superimpose a toner image formed on a color image carrier on an intermediate transfer member such as a transfer belt.

  However, the image transfer position with respect to the transfer belt may be shifted between a plurality of colors due to machine accuracy, transfer belt speed fluctuation, and the like. Also, due to temperature changes, the distance between the image carriers for each color and the length of the transfer belt also change, and the distance, magnification (size) and position between the colors change, and the image on the transfer belt between the colors. The transfer position may shift.

  That is, the color misregistration appears as color misregistration. In order to prevent this color misregistration, a color misregistration measurement pattern (hereinafter referred to as “color resist pattern”) is formed on the transfer belt, and color misregistration correction is performed based on the detection result of this color resist pattern. (Hereinafter referred to as “registration adjustment”).

The color resist pattern used in the color resist adjustment includes patterns for detecting various types of misregistration that can cause color misregistration in each color, that is, main scanning position deviation, sub-scanning position deviation, inclination, and magnification deviation. used.
In this case, it is necessary to form and read patterns of several to several tens of sheets in the rotation direction of the image carrier in terms of normal standard size paper. For this reason, if it is executed during image formation, it cannot be executed between images, and it is necessary to interrupt the image formation.

  The following patent documents disclose various techniques for resist adjustment in an image forming apparatus.

JP 2010-197586 A

  The start timing of registration adjustment in a general color image forming apparatus is adjustment at power-on, time-dependent adjustment (when a predetermined internal temperature (Δ3 ° C.) changes), and the like. Note that the power-on adjustment and the time-dependent adjustment use a color resist dedicated pattern, and therefore, the printing operation is stopped.

In the case of such an image forming apparatus, the temperature becomes stable after several hours have elapsed in the continuous use state, so that the time adjustment is not performed.
However, depending on the meandering of the intermediate transfer belt and the change of the primary / secondary transfer position of each color, an image inclination called skew deviation may occur over time during image formation.

  In such a case, the start timing of the time adjustment can be defined by the number of prints so that the time adjustment is executed. However, this method forcibly activates the time adjustment even when correction is not required. This causes a new problem that the image formation interruption (downtime) due to the time adjustment during image formation increases. To do.

In Patent Document 1 described above, a pattern used for stabilization correction (gamma correction or maximum density correction) or a pattern dedicated to resist adjustment is created for calibration, and the print operation is stopped to perform resist adjustment. To implement.
That is, in the conventional image forming apparatus, there is a problem that when the image forming operation is being executed, the color registration adjustment cannot be executed without stopping the image forming being executed.

  The present invention has been made in view of such a problem, and provides an image forming apparatus and an image forming control program capable of executing appropriate color registration adjustment without stopping an image forming operation being executed. It aims to be realized.

In order to solve the above-described problems, an image processing apparatus and an image formation control program reflecting one aspect of the present invention are configured as follows.
(1) An image forming apparatus according to the present invention includes an image forming unit that forms an image by transferring an image formed on an image carrier using a plurality of color materials onto a sheet, and one of the plurality of colors. And a control unit having a function of performing registration adjustment for adjusting an image formation position by a color material of another color with respect to an image formation position by a color material of the reference color using the color as a reference color. The control unit adjusts based on a first resist adjustment that performs adjustment based on a first pattern corresponding to a plurality of inspection items and a second pattern that corresponds to inspection items smaller than the first resist adjustment. A function of selecting and executing one of the second registration adjustments to be performed, and controlling the image forming unit to perform the second registration adjustment without interrupting the image forming operation being performed. Features.

  An image forming control program according to the present invention includes an image forming unit that forms an image by transferring an image formed on an image carrier using a plurality of color materials onto a sheet, and one color among the plurality of colors Is used as a reference color, and the resist adjustment for adjusting the image forming position by the color material of the other color with respect to the image forming position by the color material of the reference color is adjusted based on the first pattern corresponding to a plurality of inspection items. A function of selecting and executing either the first resist adjustment to be performed or the second resist adjustment to be performed based on the second pattern corresponding to the inspection items fewer than the first resist adjustment. The computer of the image forming apparatus functions as a control unit that controls the image forming unit so as to perform the second registration adjustment without interrupting the image forming operation.

  (2) In the above (1), when the control unit performs the first resist adjustment, the controller carries the first pattern for adjustment based on an inspection item for the first resist adjustment. When the first resist adjustment is performed on the body and the second resist adjustment is performed, the second pattern corresponding to the execution of other functions and corresponding to the inspection item of the second resist adjustment is applied to the image. It is formed on a carrier, and the second resist adjustment is performed together with the execution of the other functions.

(3) In the above (2), the other function is toner disposal, and the second pattern is a pattern used for toner disposal.
(4) In the above (1) to (3), the control unit performs the image formation so as to perform the second resist adjustment when the use of the color material is equal to or less than a predetermined amount in the image forming operation being executed. Part is controlled.

(5) In the above (1) to (4), the control unit has an area where the second pattern is formed smaller than an area where the first pattern is formed in the rotation direction of the image carrier. It is characterized by that.
(6) In the above (1) to (5), the control unit controls the image forming unit to perform the second resist adjustment so that an inspection item includes inclination correction.

  (7) In the above (1) to (6), when a tilt that needs to be tilt corrected is detected in the second resist adjustment, the control unit performs the second resist to be executed next. When the image forming unit is controlled to form the second pattern by applying the tilt correction in the adjustment, and the tilt is equal to or less than a predetermined value in the second pattern formed by applying the tilt correction In addition, the image forming unit is controlled to apply the tilt correction to image data to be image-formed.

  (8) In the above (7), the control unit forms an image before the inclination correction is applied when an inclination requiring application of the inclination correction is detected in the second registration adjustment. The image forming unit is controlled to apply the tilt correction to the image data thus added to form an image.

  (9) In the above (1) to (8), the control unit performs the second registration to be executed next when an inclination requiring application of inclination correction is detected in the second registration adjustment. When the image forming unit is controlled to form the second pattern by applying the inclination correction in the adjustment, and the inclination does not fall below a predetermined value in the second pattern formed by applying the inclination correction. The image forming unit is controlled to perform the first resist adjustment.

(10) In the above (1) to (8), the control unit interrupts the image forming operation that is being executed when an inclination greater than a predetermined threshold is detected in the second registration adjustment. The image forming unit is controlled to perform the first resist adjustment.
(11) In the above (1) to (10), the control unit performs the first resist adjustment using the first pattern for detecting the main scanning position deviation, the sub-scanning position deviation, the inclination, and the magnification deviation. The image forming unit is controlled to perform second resist adjustment using a second pattern for detecting sub-scanning position deviation and inclination.

According to the image processing apparatus and the image formation control program reflecting one aspect of the present invention, the following effects can be obtained.
(1) In the image forming apparatus and the image forming control program according to the present invention, the first registration adjustment for adjusting based on the first pattern corresponding to a plurality of inspection items, and the inspection items smaller than the first registration adjustment are supported. The second registration adjustment is performed by selecting one of the second registration adjustments to be performed based on the second pattern to be performed, and is controlled to perform the second registration adjustment without interrupting the image forming operation being performed. Accordingly, it is possible to execute the second registration adjustment between the images while the image is being formed, and to perform the appropriate color registration adjustment without stopping the image forming operation being executed.

  (2) In the above (1), when the first resist adjustment is performed, a first pattern for adjustment based on the inspection item of the first resist adjustment is formed on the image carrier, and the first resist is adjusted. When performing the resist adjustment and the second resist adjustment, a second pattern corresponding to the execution of other functions and corresponding to the inspection items of the second resist adjustment is formed on the image carrier between the images. By performing the second registration adjustment together with the execution of the above, other functions are executed between the images while the image is being formed, and the second registration adjustment is executed between the images without stopping the image forming operation being executed. Appropriate color resist adjustment can be executed.

  (3) In the above (2), the other function is toner discarding, and the second pattern is a pattern used for toner discarding. It is possible to execute the two color registration adjustment between the images and perform the proper color registration adjustment without stopping the image forming operation being executed.

  (4) In the above (1) to (3), during the image formation, the second resist adjustment is controlled when the use of the color material is a certain amount or less in the image forming operation being executed. For example, waste of overcharged toner due to low usage is executed between images, and second registration adjustment is executed between images, and appropriate color registration adjustment is executed without stopping the image forming operation being executed. It becomes possible.

  (5) In the above (1) to (4), the area on which the second pattern is formed is smaller than the area on which the first pattern is formed in the rotation direction of the image carrier. For example, it is possible to execute the second registration adjustment between the images and perform the appropriate color registration adjustment without stopping the image forming operation being executed.

  (6) In the above (1) to (5), by performing control so that the second registration adjustment is performed so that the inspection item includes the inclination correction, the second registration adjustment for the inclination correction is performed during image formation. It is possible to execute appropriate color registration adjustment without stopping the image forming operation being executed.

  (7) In the above (1) to (6), when an inclination that requires application of inclination correction is detected in the second registration adjustment, the inclination correction is applied in the second registration adjustment to be executed next. Control to form the second pattern, and when the inclination of the second pattern formed by applying the inclination correction becomes equal to or less than a predetermined value, the inclination correction is applied to the image data to be image-formed. As a result, the second registration adjustment is performed between the images during the image formation, the inclination detection and the inclination correction are executed only for the second pattern first, and the image data is corrected after an appropriate inclination correction state is obtained. Therefore, it is possible to perform appropriate color registration adjustment without stopping the image forming operation being executed.

  (8) In the above (7), when an inclination that requires application of the inclination correction is detected in the second registration adjustment, the inclination of the image data formed before the inclination correction is applied is determined. By applying correction and controlling to form an additional image, when performing the second registration adjustment between images during image formation, only the second pattern is executed for tilt detection and tilt correction first. When the image data is corrected after an appropriate tilt correction state, an image that has not been tilt corrected is added and formed with an appropriate tilt correction. Appropriate color registration adjustment can be executed without stopping.

  (9) In the above (1) to (8), when an inclination that requires application of inclination correction is detected in the second registration adjustment, the inclination correction is applied in the second registration adjustment to be executed next. If the second pattern formed by applying inclination correction is controlled to perform the first resist adjustment when the inclination does not become a predetermined value or less, the inclination is slight. In the state, the simple second registration adjustment is performed without stopping the image forming operation being executed, and in the state where the inclination is not slight, the image forming operation being executed is stopped and the first registration adjustment of all items is executed. Is possible.

  (10) In the above (1) to (8), when an inclination greater than a predetermined threshold is detected in the second registration adjustment, the image forming operation being executed is interrupted and the first registration adjustment is performed. By controlling the image forming unit to perform, a simple second registration adjustment is performed without stopping the image forming operation being executed when the inclination is slight, and the image forming operation being executed when the inclination is not slight. And the first registration adjustment for all items can be executed.

  (11) In the above (1) to (10), the first registration adjustment is performed using the first pattern for detecting the main scanning position deviation, the sub-scanning position deviation, the inclination, and the magnification deviation, and the sub-scanning position deviation. In addition, by performing control so that the second registration adjustment is performed using the second pattern for detecting the inclination, simple second registration adjustment is executed in a state where the inclination is slight, and the image forming operation being executed is stopped. Therefore, it is possible to execute appropriate color registration adjustment. Further, in a state where the inclination is not slight, it is possible to execute the appropriate color registration adjustment by stopping the image forming operation being executed and executing the first registration adjustment for all items.

1 is a block diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment of the present invention. 1 is an explanatory diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment of the present invention. 6 is a flowchart illustrating an operation of the image forming apparatus according to the embodiment of the present invention. It is explanatory drawing which shows the pattern used by adjustment of embodiment of this invention. FIG. 6 is an explanatory diagram illustrating an operation state of the image forming apparatus according to the embodiment of the present invention. 6 is a flowchart illustrating an operation of the image forming apparatus according to the embodiment of the present invention. FIG. 6 is an explanatory diagram illustrating an operation state of the image forming apparatus according to the embodiment of the present invention. FIG. 6 is an explanatory diagram illustrating an operation state of the image forming apparatus according to the embodiment of the present invention. FIG. 6 is an explanatory diagram illustrating an operation state of the image forming apparatus according to the embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings.
〔Constitution〕
The configuration of the image forming apparatus according to the present embodiment will be described with reference to the block diagram of FIG. 1 and the configuration diagram of FIG.

The image forming apparatus 100 includes a control unit 101, a communication unit 102, an operation display unit 103, a storage unit 104, a paper feeding unit 105, a transport unit 110, an image data storage unit 130, an image processing unit 140, an image forming unit 150, a registration sensor. 160 is comprised.
The control unit 101 controls each unit in the image forming apparatus 100. The communication unit 102 communicates with other devices. The operation display unit 103 notifies the control unit 101 of an operation input signal corresponding to the operation input by the user and displays the status of the image forming apparatus 100. The storage unit 104 stores a control program and various setting data and is used as a work area for the control program. The paper feeding unit 105 feeds the stored paper. The transport unit 110 transports paper that is fed and printed at a predetermined speed. The image data storage unit 130 stores image data and various data for printing. The image processing unit 140 executes various image processes necessary for printing.

  The image forming unit 150 executes image formation (which means a series of operations such as image formation, transfer, and fixing, and is collectively referred to as “print”) based on the print command and the image data after image processing. Further, the image forming unit 150 forms a pattern for resist adjustment on the image carrier between the image regions (between images). The registration sensor 160 detects the position and inclination of the pattern formed on the image carrier of the image forming unit 150.

  Further, the image forming unit 150 is configured as shown in FIG. Here, the image forming unit 150 includes, for each color (YMCK) of the color material, image carriers 151Y to 151K, charging units 152Y to 152K, exposure units 153Y to 153K, developing units 154Y to 154K, and transfer units. 155Y to 155K. The image forming unit 150 includes an intermediate transfer member 157, a transfer unit 158, and a fixing unit 159.

Note that the term “image carrier” includes not only the image carriers 151Y to 151K of the respective colors but also the intermediate transfer member 157 on which the toner images of the respective colors are superimposed.
Here, the charging units 152Y to 152K for the respective colors charge the image carriers 151Y to 151K for the respective colors at a predetermined potential. Then, electrostatic latent images are formed for the respective colors on the image carriers 151Y to 151K of the respective colors by exposure from the exposure units 153Y to 153K corresponding to the image data of the respective colors. The developing sections 154Y to 154K for the respective colors develop the electrostatic latent images for the respective colors formed on the image carriers 151Y to 151K for the respective colors to form toner images for the respective colors. The transfer sections 155Y to 155K for the respective colors transfer the respective color toner images on the respective color image carriers 151Y to 151K to the intermediate transfer body 157. In the intermediate transfer member 157, the color toner images on the color image carriers 151Y to 151K are superposed in an aligned state to form a color image. The transfer unit 158 transfers the color image on the intermediate transfer member 157 to a sheet. The fixing unit 159 fixes the toner image on the paper with heat and pressure.

  Further, the registration sensor 160 reads the first pattern and the second pattern formed on the intermediate transfer body 157 for registration adjustment, and various kinds of deviations that can cause color deviation in each color, that is, main scanning position deviation. Sub-scanning position deviation, inclination, magnification deviation, and the like are detected.

  In FIG. 2, the vertical direction in FIG. 2 of the cylindrical image carriers 151Y to 151K and the belt-shaped intermediate transfer member 157 is defined as a first direction (main scanning direction), and the image carriers 151Y to 151K and intermediate A rotation direction around the central axis of the transfer body 157 is defined as a second direction (sub-scanning direction).

[Operation (1) of the embodiment]
Hereinafter, an operation of the image forming apparatus as the first embodiment and an image forming control program for controlling the image forming apparatus will be described with reference to a flowchart shown in FIG. In FIG. 4, the intermediate transfer body 157 on which an image or pattern is formed is schematically shown together with the sensors 160s1, 160s2, and 160s3.

  When the image forming apparatus 100 is turned on, the control unit 101 initializes each unit in the image forming apparatus 100 (step S101 in FIG. 3). After the initialization operation is completed, the control unit 101 controls the image forming unit 150 to print the first pattern (see FIG. 4A) and execute the first registration adjustment as the power-on adjustment (see FIG. 4A). Step S102 in FIG. 3).

  As the color resist pattern at the time of the first resist adjustment, various types of misregistration that can cause color misregistration in each color, that is, main scanning position deviation, sub-scanning position deviation, inclination, and magnification deviation are detected. The first pattern shown in 4 (a) is used. In the case of the first registration adjustment, it is necessary to form and read patterns of several to several tens of sheets in terms of the normal standard size in the sub-scanning direction.

  As this first pattern, “F” -shaped marks of the same color are formed at respective positions of the registration sensor 160 (160s1, 160s2, 160s3) in the main scanning direction, and these are sequentially color-coded (K, M, C, Y). , K, M, C, Y,...

  Here, since the three registration sensors 160s1 to 160s3 are arranged in the main scanning direction, three K marks are formed at the sensor corresponding positions in the main scanning direction, and then three C marks are formed. Subsequently, three M marks are formed, and then three Y marks are formed to form one set. Then, this set is sequentially repeated in the sub-scanning direction and printed on the intermediate transfer member 157.

  In the case of this first registration adjustment, the position shift in the sub-scanning direction of the horizontal line of the “F” -shaped mark (line in the main scanning direction) depends on the distance to the horizontal lines of C, M, and Y with respect to the K horizontal line. (Color shift) can be detected. Further, in each color KCMY, a positional deviation in the main scanning direction of each color KCMY can be detected by obtaining the distance between the horizontal line and the diagonal line of the “F” -shaped mark. Further, in each color KCMY, by detecting the difference between the horizontal line in the main scanning direction and the left side in the main scanning direction with respect to the distance between the horizontal line and the diagonal line of the “F” -shaped mark, a magnification shift in the main scanning direction of each color KCMY is detected. can do.

  In the image forming apparatus 100 in which the first registration adjustment is completed and an image can be formed, the control unit 101 waits for a print execution instruction from the operation display unit 103 or an external device (in FIG. 3). Step S103). When a print execution instruction is issued from the operation display unit 103 or an external device (YES in step S1023 in FIG. 3), the control unit 101 instructs the image processing unit 140 and the image forming unit 150 based on image data in the image area. An instruction to print the image on a sheet is given (step S104 in FIG. 3).

  Here, the control unit 101 refers to the measurement result of the in-machine temperature in the image forming unit 150 and checks whether or not a predetermined temperature (for example, ± 3 ° C.) has changed since the previous measurement. If there is a change in temperature (YES in step S105 in FIG. 3), the currently executed print (operation for forming an image in the image area based on the image data) is temporarily suspended (in FIG. 3). In step S106, the image forming unit 150 is controlled so that the first pattern (FIG. 4A) is printed on the intermediate transfer member 157 and the first resist adjustment is performed as the temporal adjustment (step S107 in FIG. 3). .

  In this case, when the temperature inside the apparatus rises by a predetermined temperature, various misalignments that may cause color misregistration in each color, that is, main scanning position deviation, sub-scanning position deviation, inclination, and magnification deviation occur. there's a possibility that. Therefore, the first pattern shown in FIG. 4A is used to detect various types of misregistration that can cause color misregistration in each color, that is, main scanning position deviation, sub-scanning position deviation, inclination, and magnification deviation. And adjust over time. Note that in the case of this first registration adjustment, it is necessary to print and read patterns of several to several tens of sheets on the intermediate transfer body 157 in terms of normal paper in the sub-scanning direction. The first pattern cannot be printed between the images, and the currently executed image print is temporarily suspended.

If an unexecuted image print exists at the time when the time adjustment is completed (not completed in step S120 in FIG. 3), the image print is resumed (step S104 in FIG. 3).
On the other hand, when the image forming unit 150 does not change the internal temperature beyond the predetermined temperature and adjustment with time is not necessary (NO in step S105 in FIG. 3), the control unit 101 is processed by the image processing unit 140. The use amount of each color toner is confirmed with reference to the image data (step S108 in FIG. 3). Here, when the image printing operation with a small amount of toner used continues, the toner in the developing units 154Y to 154K is overcharged, and as a result, the development density unevenness is likely to occur.

  Therefore, when the image printing operation with a small amount of toner used continues, a second pattern (FIG. 4B) called a discard band is printed between the images on the intermediate transfer member 157, and the developing units 154Y to 154Y. The control unit 101 determines to discard the toner with a small usage amount in 154K (YES in step S109 in FIG. 3).

  Further, even when the printing operation in a state where the toner usage is small is not continuous (NO in step S109 in FIG. 3), the image printing in a state where the toner is not discarded is continuously executed for a predetermined number or more. If so, the control unit 101 determines to print the same second pattern (FIG. 4B) between the images on the intermediate transfer member 157 (YES in step S110 in FIG. 3).

  Based on the above determination, the control unit 101 controls the image forming unit 150 to print the second pattern between the images on the intermediate transfer member 157 (step S111 in FIG. 3). As the second pattern, as shown in FIG. 4B, between the adjacent image areas G1 to G5, areas of the colors K, C, M, and Y are not transferred to the sheet (non-transfer areas). A band pattern Pb in the main scanning direction is printed. Note that the second pattern (FIG. 4B) is printed between the images between the image areas, and therefore has no effect on the currently executed image print.

In this case, the second pattern formed on the intermediate transfer body 157 is collected and discarded by a cleaning unit (not shown) without being transferred to a sheet or the like.
When the second pattern is printed, the control unit 101 detects the deviation of each pattern based on the detection results of the sensors 160s1, 160s2, and 160s3 (step S112 in FIG. 3). Hereinafter, with reference to FIG. 5, the detection of deviation in the second resist adjustment using the second pattern will be described.

Pb1_K, Pb1_C, Pb1_M, and Pb1_Y are printed as a belt-like second pattern between the image area G1 and the image area G2.
Here, Pb1_K is used as a reference. Then, the detection results of the sensors 160s1, 160s2, and 160s3 are checked with respect to the interval between Pb1_K and Pb1_C. If the detection results are equal, no difference is detected, and if the detection results are different, it is detected that there is a difference. Similarly, the detection results of the sensors 160s1, 160s2, and 160s3 are checked with respect to the interval between Pb1_K and Pb1_M. If the detection results are equal, no difference is detected, and if the detection results are different, it is detected that there is a difference. Similarly, the detection results of the sensors 160s1, 160s2, and 160s3 are checked with respect to the interval between Pb1_K and Pb1_Y. If the detection results are equal, there is no deviation, and if the detection results are different, it is detected that there is a deviation.

  In the second pattern (Pb1_K, Pb1_C, Pb1_M, Pb1_Y) between the image area G1 and the image area G2, no shift is detected (NO in step S113 in FIG. 3). If the deviation is not corrected by registration adjustment and there is an unexecuted image print (uncompleted in step S120 in FIG. 3), the next image print is executed (step S104 in FIG. 3).

  In the image region G2, it is assumed that no inclination occurs in the K, C, and M images, but the Y image g2_Y has an inclination in a line in the main scanning direction. Also, Pb2_K, Pb2_C, Pb2_M, and Pb2_Y are printed as the second band-shaped pattern between the image area G2 and the image area G3. In this case, the detection results of the sensors 160s1, 160s2, and 160s3 are equal for the interval between Pb2_K and Pb2_C, and it is detected that there is no deviation. Further, the detection results of the sensors 160s1, 160s2, and 160s3 are equal for the interval between Pb2_K and Pb2_M, and it is detected that there is no deviation. Then, the detection results of the sensors 160s1, 160s2, and 160s3 are not equal with respect to the interval between Pb2_K and Pb2_Y, and there is a difference, and it is detected that there is a deviation (YES in step S113 in FIG. 3).

When the shift is detected in this way, the control unit 101 controls the image forming unit 150 to print an image based on the next image data in a state in which Y having an inclination is not corrected in the next image region G3 ( Step S114 in FIG.
Then, the control unit 101 obtains the inclination for Pb2_Y in the above second pattern, calculates correction data that should eliminate the inclination, applies correction data to Pb3_Y to be printed between the next images, and shifts in advance. Is corrected so as to be eliminated (step S115 in FIG. 3).

It should be noted that the image print that is not corrected (step S114 in FIG. 3) and the application of the correction data (step S115 in FIG. 3) may be performed in parallel in a state where the deviation is detected as described above. Either one can be executed first.
In the second pattern (Pb3_K, Pb3_C, Pb3_M, Pb3_Y) between the image area G3 and the image area G4, Pb3_K, Pb3_C, Pb3_M are printed as usual, and correction data is applied to Pb3_Y. Is printed (step S116 in FIG. 3).

Here, with respect to Pb3_Y printed as the second pattern in a state where the correction data is applied, the control unit 101 determines whether or not there is a deviation (whether or not the deviation is eliminated) from the detection results of the sensors 160s1, 160s2, and 160s3. Is detected (step S117 in FIG. 3).
Note that no deviation or elimination of deviation does not mean that the detected deviation is completely eliminated, but means that the deviation has been reduced to a level that does not cause a problem in practice.

  Here, if the deviation is not eliminated for Pb3_Y (NO in step S118 in FIG. 3), the control unit 101 applies the next image deviation correction (step S114 in FIG. 3) and the second pattern deviation correction (FIG. 3). 3 (step S115 in FIG. 3), printing of the second pattern (step S116 in FIG. 3), and detection of presence / absence of displacement of the second pattern (step S117 in FIG. 3) are repeated. Control.

  On the other hand, if the deviation has been eliminated for Pb3_Y (YES in step S118 in FIG. 3), the control unit 101 applies the correction data to the image data of the next image area (in this case, the Y image). The image processing unit 140 and the image forming unit 150 are controlled so that the correction data is applied to the data (step S119 in FIG. 3). In the example of FIG. 5, as a result of the elimination of the deviation by Pb3_Y of the second pattern, the correction data is applied to the images after G4, and the deviation is eliminated.

Then, if there is an unexecuted image print (uncompleted in step S120 in FIG. 3), the control unit 101 executes the next image print (step S104 in FIG. 3), as described above. Repeat the process of each step described.
In addition, the control unit 101 is in a state where there is no unexecuted image print, but a shift is detected in the second pattern described above (YES in step S113 in FIG. 3), and an image print in which a shift has occurred (FIG. In the example of FIG. 5, when G2 and G3) are output (there is a shift print in step S120 in FIG. 3), image processing is performed so that reprinting is performed with correction data applied to the image print in which the shift has occurred. The unit 140 and the image forming unit 150 are controlled (step S121 in FIG. 3). Further, in this case, the control unit 101 displays, on the operation display unit 103, the presence of the image print in which the deviation has occurred and the presence of the reprint in a state in which the deviation is eliminated by applying the correction data together with the number of pages. Control to display.

  Further, when there is no unexecuted image print and the image print in which the deviation has occurred is not output (completed in step S120 in FIG. 3), the control unit 101 completes the above series of prints. The image processing unit 140 and the image forming unit 150 are controlled to end the processing. In this case, the control unit 101 controls the operation display unit 103 to display completion of printing.

In the above description, the case where the deviation occurs in Y is described as a specific example. However, even if the deviation occurs in other colors or in a plurality of colors at the same time, the same process as the above process is executed for the corresponding color. It ’s fine.
[Operation (2) of the embodiment]
Hereinafter, an operation of the image forming apparatus as the second embodiment and an image forming control program for controlling the image forming apparatus will be described with reference to a flowchart shown in FIG. 6 and an explanatory diagram of FIG. In FIG. 7, the intermediate transfer body 157 on which an image or pattern is formed is schematically shown together with the sensors 160s1, 160s2, and 160s3. In the flowchart of FIG. 6, the same processes as those in the flowchart of FIG. 3 are denoted by the same step numbers, and redundant description is omitted.

The control unit 101 prints the above second pattern between the images of the intermediate transfer member 157, and detects the shift of each pattern based on the detection results of the sensors 160s1, 160s2, and 160s3 (step S112 in FIG. 6).
Here, a threshold for determining whether to perform the second registration adjustment without interrupting the image forming operation being performed or to shift to the first registration adjustment by interrupting the image forming operation being performed is determined in advance. Keep it. That is, in a state where the inclination is slight, simple second registration adjustment is executed using a simple second pattern, and appropriate color registration adjustment is executed without stopping the image forming operation being executed. On the other hand, in a state where the inclination is not slight, it is desirable to execute the appropriate color registration adjustment by stopping the image forming operation being executed and executing the first registration adjustment for all items. Therefore, a deviation threshold for switching between the first registration adjustment and the second registration adjustment is determined and stored in advance in the storage unit 104 or the like.

  Accordingly, when a deviation greater than a predetermined threshold is detected in the second registration adjustment with respect to the detected deviation (YES in step S113 in FIG. 6 (greater than the threshold)), the control unit 101 performs the print being executed. (Operation for forming an image in the image area based on the image data) is temporarily interrupted (step S106 in FIG. 6), the first pattern (FIG. 4A) is printed, and the first resist adjustment is performed. The image forming unit 150 is controlled to be executed as time adjustment (step S107 in FIG. 6). For example, when a shift greater than or equal to the threshold is detected in the second pattern Pb in FIG. 7, the process proceeds to the first registration adjustment using the first pattern Pa.

  On the other hand, when a slight deviation less than the predetermined threshold is detected in the second registration adjustment (YES in step S113 in FIG. 6 (less than the threshold)), the control unit 101 performs the image forming operation being performed. The image forming unit 150 is controlled to perform the second registration adjustment without interruption (steps S114 and thereafter in FIG. 6).

As described above, the simple second registration adjustment is performed without stopping the image forming operation being executed when the inclination is slight, and the image forming operation being executed is stopped when the inclination is not slight. Thus, the first registration adjustment of all items can be executed.
Further, the control unit 101 determines whether or not there is a deviation (whether or not the deviation is eliminated) from the detection results of the sensors 160s1, 160s2, and 160s3 for Pb3_Y printed as the second pattern in a state where the correction data is applied. Detection is performed (step S117 in FIG. 6). Note that no deviation or elimination of deviation does not mean that the detected deviation is completely eliminated, but means that the deviation has been reduced to a level that does not cause a problem in practice.

  If the deviation has not been eliminated for Pb3_Y (NO in step S118 in FIG. 6), the control unit 101 temporarily suspends the print being executed (the operation for forming an image in the image area based on the image data). In this manner (step S106 in FIG. 6), the image forming unit 150 is controlled to print the first pattern (FIG. 4A) and execute the first resist adjustment as the time-dependent adjustment (in FIG. 6). Step S107).

  On the other hand, if the deviation has been eliminated for Pb3_Y (YES in step S118 in FIG. 3), the control unit 101 applies the correction data after the image data of the next image area as described above. Then, the second registration adjustment is completed by controlling the image processing unit 140 and the image forming unit 150 (step S119 in FIG. 3).

  By doing as described above, if the deviation is eliminated in the second pattern to which the correction data is applied, the simple second registration adjustment is performed without stopping the image forming operation being executed, and the correction data is applied. If the deviation is not eliminated in the two patterns, it is possible to stop the image forming operation being executed and execute the first registration adjustment for all items.

[Operation (3) of the embodiment]
The operation of the image forming apparatus as the third embodiment and an image formation control program for controlling the image forming apparatus will be described below with reference to the explanatory diagram of FIG. In FIG. 8, the intermediate transfer member 157 on which an image or pattern is formed is schematically shown together with the sensors 160s1, 160s2, and 160s3.

  When the image printing operation with a small amount of toner used continues, a second pattern called a discard band is printed between the images on the intermediate transfer member 157, and the toner with a small amount of use is developed in the developing units 154Y to 154K. The control unit 101 determines to discard (YES in step S109 in FIG. 3 or FIG. 6). Here, the second pattern (Pb1_K, Pb1_C, Pb1_M, Pb1_Y) between the image area G1 and the image area G2 is the second pattern used for toner disposal, and thereby the second resist adjustment is executed. The

When an image printing operation with a large amount of toner used is executed, a second pattern called a discard band is not formed. Here, since the amount of toner used is large in the image region G2 in FIG. 8, toner discard is not executed between the images after G2.
However, even when there is no need to discard toner, it is desirable from the viewpoint of image quality to perform the second resist adjustment described above. Therefore, even when the printing operation in a state where the toner usage is small is not continuous (NO in step S109 in FIG. 3 or FIG. 6), the image printing in a state where the toner is not discarded continues for a predetermined number or more. If executed, the control unit 101 determines to print a pattern similar to the second pattern (FIG. 4B) between images (YES in step S110 in FIG. 3 or FIG. 6). ).

  Here, in the second pattern (Pb3_K, Pb3_C, Pb3_M, Pb3_Y) between the image region G3 and the image region G4, since there is no need to discard the toner, the pattern is as thin as possible and can be detected by the sensor. Is forming. As a result, the second registration adjustment can be performed periodically without wasting toner.

  Similarly, for the second pattern (Pb5_K, Pb5_C, Pb5_M, Pb5_Y) after the image region G5, there is no need to discard the toner, so that a pattern that is as thin as possible can be detected by the sensor. . As a result, the second registration adjustment can be performed periodically without wasting toner.

In this embodiment, although not shown, a thick pattern for discarding toner may be mixed with a thin pattern for adjusting only without toner discard.
[Operation (4) of the embodiment]
The operation of the image forming apparatus as the fourth embodiment and an image formation control program for controlling the image forming apparatus will be described below with reference to the explanatory diagram of FIG. In FIG. 9, the intermediate transfer body 157 on which an image or pattern is formed is schematically shown together with the sensors 160s1, 160s2, and 160s3.

  When the image printing operation with a small amount of toner used continues, as shown in FIG. 9A, a second pattern called a discard band is printed between the images and used in the developing units 154Y to 154K. The control unit 101 determines to discard the small amount of toner. Here, the second pattern (Pb1_K, Pb1_C, Pb1_M, Pb1_Y) between the image area G1 and the image area G2 is the second pattern used for toner disposal, and thereby the second resist adjustment is executed. The

  At this time, as the second pattern between the image region G1 and the image region G2, as shown in FIG. 9B, the first half second pattern (Pb1_K1, Pb1_C1, Pb1_M1, Pb1_Y1) and the second half second pattern ( Pb1_K2, Pb1_C2, Pb1_M2, and Pb1_Y2) are possible. In this case, the width of the pattern is adjusted so that the required toner discard amount is obtained as a whole. By doing so, it is possible to improve the accuracy of deviation detection by executing deviation detection and correction effect confirmation multiple times and averaging. The fourth embodiment can also be applied to the third embodiment described above.

[Other Embodiments]
In each of the embodiments described above, the control unit 101 controls each unit so as to perform the second registration adjustment so that the inspection item includes inclination correction. However, the present invention is not limited to this. For example, using the second pattern, whether or not any of the other colors CMY is misaligned in the sub-scanning direction (sub-scanning direction misalignment) with reference to K can be included as an inspection item. .

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 101 Control part 102 Communication part 103 Operation display part 104 Memory | storage part 105 Paper feeding part 110 Conveyance part 120 Original reading part 130 Image data storage part 140 Image processing part 150 Image forming part 160 Registration sensor

Claims (12)

An image forming unit that forms an image by transferring an image formed on an image carrier using a plurality of color materials onto paper;
A control unit having a function of performing registration adjustment for adjusting an image forming position by a color material of another color with respect to an image forming position by a color material of the reference color using one of the plurality of colors as a reference color;
An image forming apparatus comprising:
The controller is
A first resist adjustment for performing adjustment based on a first pattern corresponding to a plurality of inspection items, and a second resist adjustment for performing adjustment based on a second pattern corresponding to fewer inspection items than the first resist adjustment. It has a function to select and execute either
Controlling the image forming unit to perform the second registration adjustment without interrupting an image forming operation being performed;
An image forming apparatus. The controller is
When performing the first resist adjustment, the first resist adjustment is performed by forming the first pattern on the image carrier for adjustment based on the inspection item of the first resist adjustment,
When performing the second resist adjustment, the second pattern corresponding to the second registration adjustment and the second pattern corresponding to the inspection item of the second registration adjustment is formed on the image carrier, and the second function is performed along with the execution of the other function. Perform second resist adjustment.
The image forming apparatus according to claim 1. The other function is toner disposal,
The second pattern is a pattern used for the toner disposal.
The image forming apparatus according to claim 2. The control unit controls the image forming unit to perform the second resist adjustment when the use of a color material is equal to or less than a predetermined amount in an image forming operation being performed;
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The control unit has an area where the second pattern is formed smaller than an area where the first pattern is formed in the rotation direction of the image carrier.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The control unit controls the image forming unit to perform the second registration adjustment so that an inspection item includes inclination correction.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The controller is
When an inclination that requires application of inclination correction is detected in the second registration adjustment, the image is so formed that the inclination correction is applied and the second pattern is formed in the second registration adjustment to be executed next. Control the forming part,
Controlling the image forming unit to apply the inclination correction to image data to be image-formed when the inclination is equal to or less than a predetermined value in the second pattern formed by applying the inclination correction;
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The controller is configured to perform the tilt correction on the image data that has been formed before the tilt correction is applied when a tilt that requires the tilt correction to be applied is detected in the second registration adjustment. Controlling the image forming unit to apply and add to form an image;
The image forming apparatus according to claim 7. The controller is
When an inclination that requires application of inclination correction is detected in the second registration adjustment, the image is so formed that the inclination correction is applied and the second pattern is formed in the second registration adjustment to be executed next. Control the forming part,
Controlling the image forming unit to perform the first resist adjustment when the inclination does not fall below a predetermined value in the second pattern formed by applying the inclination correction;
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The controller is
When an inclination equal to or greater than a predetermined threshold is detected in the second registration adjustment,
Controlling the image forming unit so as to perform the first registration adjustment by interrupting the image forming operation being executed;
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The control unit performs a first registration adjustment using a first pattern for detecting a main scanning position deviation, a sub-scanning position deviation, an inclination, and a magnification deviation, and a second pattern for detecting the sub-scanning position deviation and the inclination. Controlling the image forming unit to perform the second resist adjustment,
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. An image forming unit that forms an image by transferring an image formed on an image carrier using a plurality of color materials onto paper;
For one of the plurality of colors as a reference color, a resist adjustment for adjusting an image formation position by a color material of another color with respect to an image formation position by a color material of the reference color corresponds to a plurality of inspection items. Select and execute either a first resist adjustment that performs adjustment based on the first pattern or a second resist adjustment that performs adjustment based on the second pattern corresponding to inspection items smaller than the first resist adjustment A control unit that controls the image forming unit to perform the second registration adjustment without interrupting the image forming operation being performed,
As an image forming control program for causing a computer of an image forming apparatus to function.