JP2015079159A - Image forming apparatus and image formation control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly correct color misregistration when an image is formed in different pressure-contact states using different color materials.SOLUTION: An image forming apparatus includes: an image forming section with a pressure-contact mechanism having a plurality of pressure-contact states depending on printing conditions; a control section which controls the image forming section to perform image adjustment in the plurality of pressure-contact states; and a storage section which holds a result of the image adjustment for each of the pressure-contact states. The control section reads an adjustment result corresponding to the pressure-contact state from the storage section when the pressure-contact state is changed, and forms an image on the basis of the adjustment result, to change the result of the image adjustment when the pressure-contact state is changed, thereby printing a proper image free from color misregistration without generating downtime.

Description

  The present invention relates to an image forming apparatus and an image formation control method capable of forming an image with a crimping mechanism having a plurality of crimping states.

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

However, the image transfer position with respect to the transfer belt may shift 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 change, the distance between the colors changes, and the image transfer position onto the transfer belt may shift between colors.
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. It is carried out.

Furthermore, in Patent Document 1, in order to prevent color misregistration due to the amount of toner on the photosensitive drum, etc., a color misregistration correction value corresponding to the printing rate is recorded, and the color misregistration corresponding to the printing rate is recorded. An image forming apparatus to be corrected has been proposed.
In Patent Document 2, it is possible to perform image formation using a toner image of a special color in addition to yellow, magenta, cyan, and black, and an image carrier and transfer belt of an image forming unit that do not contribute to image formation. There has been proposed an image forming apparatus for separating them.

JP 2006-154072 A JP 2004-219613 A

By the way, as in Patent Document 2, when the color material to be used is different depending on the printing conditions, in order to prevent the life of the photoconductor, etc., the pressure contact state of the photoconductor and the transfer belt is changed according to the color material to be used. Image formation.
However, for example, when switching from four-color crimping to five-color crimping, the transfer belt behavior changes due to the change in the tension of the transfer belt, and color registration misalignment occurs when the same color misregistration correction as in four-color crimping is performed. End up. In Patent Document 2, it is possible to change the pressure bonding conditions according to the printing conditions, but color misregistration correction according to different pressure bonding states is not performed. In Patent Document 1, although attention is paid to the printing rate, color misregistration correction according to different crimping states cannot be performed. For this reason, it is possible to perform color resist correction when the crimping state is changed, but the productivity is significantly reduced.

  The present invention has been made in the background of the above circumstances, and an image forming apparatus and an image forming apparatus that can perform image formation using an appropriate image adjustment result according to the crimping state when the crimping state is switched. The purpose is to provide a system.

That is, of the image forming apparatus according to the present invention, the first aspect of the present invention is an image forming unit having a pressure-bonding mechanism having a plurality of pressure-bonding states according to printing conditions;
A control unit that controls the image forming unit and performs image adjustment in the plurality of pressure-bonding states;
A storage unit that holds the adjustment result by the image adjustment for each crimping state,
The control unit reads an adjustment result corresponding to the crimping state from the storage unit when the crimping state is switched, and performs image formation based on the adjustment result.

  An image forming apparatus according to a second aspect of the present invention is characterized in that, in the first aspect of the present invention, the image adjustment includes color misregistration correction.

  The image forming apparatus according to a third aspect of the present invention is characterized in that, in the first or second aspect of the present invention, the plurality of pressure-bonding states are combinations of different color material pressure bonding.

  The image forming apparatus according to a fourth aspect of the present invention is the image forming apparatus according to the third aspect of the present invention, wherein the plurality of press-bonded states are five colors obtained by adding four colors of yellow, cyan, magenta and black, and four colors. It is characterized by being crimped.

  In the image forming apparatus according to a fifth aspect of the present invention, in the third or fourth aspect of the present invention, when the job is executed, the control unit repeatedly uses a part of the color material, unused the job, and used the job. When executed, the image formation is performed in a pressure-bonded state using the color material.

  The image forming apparatus according to a sixth aspect of the present invention is the image forming apparatus according to any one of the third to fifth aspects of the present invention, wherein the control unit forms an image using a part of the color materials in a press-bonded state. In this case, image formation is performed based on an image adjustment result with respect to the pressure-bonded state.

  The image forming apparatus according to a seventh aspect of the present invention is the image forming apparatus according to any one of the third to sixth aspects of the present invention, wherein the control unit performs only a part of the color materials in a press-bonded state during the image adjustment. Image adjustment is performed.

  The image forming apparatus according to an eighth aspect of the present invention is characterized in that, in any one of the first to seventh aspects of the present invention, the control unit continuously performs image adjustment in the plurality of pressure-bonded states.

  According to a ninth aspect of the present invention, in the image forming apparatus according to any one of the first to eighth aspects of the present invention, the controller adjusts the image adjustment every time a predetermined number of sheets are printed, every time a predetermined operation time elapses, or by a user setting. It is performed according to the feature.

An image forming control method according to a tenth aspect of the present invention includes an image forming unit having a pressure-bonding mechanism having a plurality of pressure-bonding states according to printing conditions, and a control unit that controls the image forming unit and performs image adjustment in the plurality of pressure-bonding states. And an image forming control method of an image forming apparatus comprising: a storage unit that holds the image adjustment result for each crimped state,
When the crimping state is switched, an image adjustment result corresponding to the crimping state is read from the storage unit, and image formation is performed based on the image adjustment result.

  An image forming control method according to an eleventh aspect of the present invention is the image forming control method according to the tenth aspect, wherein the image adjustment includes color misregistration correction.

  The image forming control method according to a twelfth aspect of the present invention is characterized in that, in the tenth or eleventh aspect of the present invention, the plurality of pressure-bonding states are combinations of different color material pressure bonding.

  The image forming control method of the thirteenth aspect of the present invention is the image forming control method according to the twelfth aspect of the present invention, wherein the plurality of pressure-bonding states are four-color pressure bonding of yellow, cyan, magenta, and black, and one color is added to the four-color pressure bonding. It is characterized by color crimping.

  In the image forming control method according to the fourteenth aspect of the present invention, in the twelfth or thirteenth aspect of the present invention, when a job is executed, job use of some color materials, job nonuse, and job use are repeatedly executed. The image formation is performed in a pressure-bonded state using the color material.

  The image formation control method according to a fifteenth aspect of the present invention is the image forming control method according to any one of the twelfth to fourteenth aspects of the present invention, wherein the image formation is performed using a part of the color materials in the pressure-bonded state. Image formation is performed based on an image adjustment result with respect to a state.

  The image forming control method of the sixteenth aspect of the present invention is the image forming control method according to any one of the twelfth to fifteenth aspects of the present invention, wherein the image adjustment is performed only for a part of the color materials in the press-bonded state during the image adjustment. It is characterized by that.

  The image formation control method according to a seventeenth aspect of the present invention is the image formation control method according to any one of the tenth to sixteenth aspects, wherein image adjustment in the plurality of pressure-bonded states is continuously performed simultaneously.

  According to an image forming control method of an eighteenth aspect of the present invention, in any one of the tenth to seventeenth aspects of the present invention, the image adjustment is performed every time a predetermined number of sheets are printed, every time a predetermined operation time elapses, or according to a setting content of a user. It is characterized by.

  As described above, according to the present invention, image adjustment is performed in a plurality of crimping states, and the adjustment result by image adjustment is switched when the crimping state is switched, without causing downtime, There is an effect that a high-quality image without color misregistration can be printed.

1 is a diagram illustrating a mechanical configuration of an image forming apparatus according to an embodiment of the present invention. Similarly, it is a figure explaining switching of a press-fit state. Similarly, it is a figure which shows a control block. Similarly, it is explanatory drawing which shows the example of the pattern used for the color shift adjustment in an example crimped state. Similarly, it is explanatory drawing which shows the example of the pattern used for the color shift adjustment in the crimping | compression-bonding state of another example. Similarly, it is a flowchart illustrating an example of a procedure for performing image adjustment based on a press-bonded state according to printing conditions. Similarly, it is a flowchart illustrating an example of a procedure of an image adjustment operation at a predetermined timing. Similarly, it is a figure which shows the example of the setting screen which sets the predetermined timing which performs image adjustment. Similarly, it is a flowchart showing an example of a procedure for performing switching of a crimping state and switching of image adjustment.

An image forming apparatus according to an embodiment of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a central sectional view of the entire image forming apparatus and shows a mechanical configuration. The configuration will be described below.
The image forming apparatus 1 is provided with a scanner unit 130 including a CCD 131 shown in FIG. 3 and a flow type automatic document feeder (ADF) (not shown) on the upper side of the image forming apparatus main body 1A. An original image can be read through the original reading slit glass 32.
In addition, an LCD 141 having a touch panel is provided at a position where the platen glass 31 is not located on the upper side of the image forming apparatus main body 1A, so that an operator can perform operations and display information. The LCD 141 constitutes an operation unit and also serves as a display unit. In the present invention, the operation unit and the display unit can be configured separately.

  In the image forming unit 10, photoconductors 11CL, 11C, 11M, 11Y, and 11K (hereinafter collectively referred to as the photoconductor 11) prepared for each color (spot color (clear), cyan, magenta, yellow, black, etc.), respectively. Called). Note that the special color (clear) is a material that causes gloss, reflection, watermark, and the like, and may be a material that includes not only completely colorless but also a slight color or a minute glossy substance. The color material is used as a colored material or a colorless material.

  The peripheral portions of the photoconductors 11CL, 11C, 11M, 11Y, and 11K are provided with a charger 12CL, 12C, 12M, 12Y, and 12K (hereinafter collectively referred to as a charger 12), and a writing unit 13CL that includes an LD. , 13C, 13M, 13Y, and 13K (hereinafter collectively referred to as the writing unit 13) and developing units 14CL, 14C, 14M, 14Y, and 14K (hereinafter collectively referred to as the developing unit 14). The surface of the photoreceptor 11 charged by the charger 12 is subjected to image exposure by the writing unit 13 based on the image information of the document recorded in the image memory or the like, and a latent image is formed on the surface of the photoreceptor 11. The The latent image is developed by the developing unit 14 to become a toner image. The toner image is transferred to the intermediate transfer belt 16, and is transferred from the intermediate transfer belt 16 to a sheet conveyed on the conveyance path 22 by the secondary transfer roller 18. The transferred paper is heated and fixed by the fixing device 19 and an image forming output (printing) is performed on the paper discharge unit.

  Further, in the image forming unit 10, corresponding to each of the photoreceptors 11CL, 11C, 11M, 11Y, and 11K, the rotation direction side of the contact position with the intermediate transfer belt 16 and the chargers 12CL, 12C, 12M, 12Y, and 12K. Cleaning units 15CL, 15C, 15M, 15Y, and 15K that contact the photoconductors 11CL, 11C, 11M, 11Y, and 11K to remove residual toner on the opposite side of the rotation direction (hereinafter collectively referred to as the cleaning unit 15). Is called). Further, residual toner on the intermediate transfer belt 16 is removed from the sheet transfer position of the intermediate transfer belt 16 in the rotation direction and on the rotation direction opposite side of the transfer position with each of the photoconductors 11CL, 11C, 11M, 11Y, and 11K. A cleaning unit 17 is disposed.

Each of the photosensitive members 11 is rotated by a drive motor (not shown), and the intermediate transfer belt 16 is also driven by a drive motor (not shown).
Further, the intermediate transfer belt 16 has a plurality of roller groups around which the intermediate transfer belt 16 is wound inside the intermediate transfer belt 16, and has a pressure-bonding mechanism 16A capable of moving part or all of the roller groups. doing. In the crimping mechanism 16A, the intermediate transfer belt 16 is separated from the photoreceptor 11CL, and the intermediate transfer belt 16 is crimped to the photoreceptors 11C, 11M, 11Y, and 11K, and the photoreceptors 11CL, 11C, and 11M. , 11Y, 11K, and the intermediate transfer belt 16 is crimped to a five-color crimped state. Further, the intermediate transfer belt 16 may be pressure-bonded only to the photoconductor 11K, and the monochrome transfer state in which the intermediate transfer belt is separated from the photoconductors 11CL, 11C, 11M, and 11Y may be possible. The intermediate transfer belt may be crimped only to the color photoconductor.

  Conventionally, a full-color printer has four colors of yellow, magenta, cyan, and black, and the crimping pattern has only two patterns of one-color crimping of black only or four-color crimping of yellow, magenta, cyan, and black. In this embodiment, in addition to the four colors, a special color (clear) toner that gives a glossy color is added. The special color toner is disposed at a point farthest from the secondary transfer belt. Even if it is a full-color print, the presence or absence of gloss depends on the user's preference, so it is up to the user to print using a special color toner. When no special color toner is used, the toner can be separated from the intermediate transfer belt 16 in order to prevent the life of the photosensitive member from being extended. The change in the crimping state is not limited to that which occurs between the photoconductor 11 and the intermediate transfer belt 16, and any change in the crimping state may be used as long as the toner image is transferred.

At the time of full-color printing, depending on whether or not the special color toner is used, there are four-color crimping and five-color crimping as shown in FIG.
In this figure, it is described that the position of the special color (clear) photoreceptor 11CL is shifted from the position of other photoreceptors in the four-color crimping, but the change in the crimping state is that the intermediate transfer belt side moves. Alternatively, the photoconductor side may be moved. Furthermore, the pressure and the separation may be made by the movement of both.
Further, in the present embodiment, the description is made on the five-color crimping and the four-color crimping. However, the crimping state may be further different depending on the color material used in image formation.

In the image forming apparatus 1, a plurality of paper feed trays 21 that store sheets are disposed below the image forming unit 10. The conveyance path 22 extends from each paper feed tray 21 to the image forming unit 10 and further from the image forming unit 10 to the paper discharge unit.
A pair of registration rollers 23 that abut the paper and correct the inclination are disposed on the conveyance path 22. In the transport path 22, the paper stored in the paper feed tray 21 is fed and transported to the secondary transfer roller 18 through the registration roller 23. The secondary transfer roller 18 transfers a color image or a monochrome image on the intermediate transfer belt 16 onto a sheet. The toner image on the paper is fixed to the paper on which the image has been transferred by applying heat and pressure in the fixing device 19.

  In addition, the image forming apparatus 1 includes a paper reversing conveyance path 24. The fixed sheet is guided from the fixing device 19 to the paper reversing conveyance path 24 so that the front and back sides are reversed and ejected face-down. It is possible to perform image formation on both sides. The sheet reversal conveyance path 24 merges with the conveyance path 22 on the upstream side of the registration roller 23 and can recirculate the sheet.

FIG. 3 shows a connection between a circuit block of the image forming apparatus 1 that is a digital multifunction peripheral (copier, printer, scanner) and an external device (PC) 2 that is an external device, and is an overall block diagram of the image forming system. is there. The contents will be described in detail below.
In this embodiment, the image forming apparatus 1 is configured by connecting the FNS unit 170 to the image forming apparatus main body 1A. However, the configuration of the image forming apparatus is not limited to this in the present invention. The image forming apparatus may be configured by only the image forming apparatus main body 1A, or may be configured by connecting another post-processing apparatus or the like.

  The image forming apparatus 1 processes a digital copier main body having a control block 110, a scanner unit 130, an operation unit 140, and a printer unit 150, and image data input from an external device (PC) 2 through the LAN 3, or a scanner unit. An image processing unit (print & scanner controller) 160 that enables the image data obtained in 130 to be transferred to an external device (PC) 2 that is an external device through the LAN 3 is provided.

  The control block 110 has a PCI bus 112 connected to an image processing unit (print & scanner controller) 160, and a DRAM control IC 111 is connected to the PCI bus 112. An image memory composed of a compression memory 120 and a page memory 121 is connected to the DRAM control IC 111. The compression memory 120 is a memory for storing compressed image data, and the page memory 121 is a memory for temporarily storing uncompressed image data to be printed before image formation.

Image data acquired by the image processing unit (print & scanner controller) 160 is transmitted to the DRAM control IC 111 through the PCI bus 112 in accordance with the printing operation.
Further, the control block 110 includes a control unit 113, and the DRAM control IC 111 is connected to the control unit 113.
The control unit 113 includes a control CPU, a program, a RAM serving as a work area, a ROM storing a program, and the like.
The control unit 113 is connected to a non-volatile memory 115 constituted by a flash memory or the like. The non-volatile memory 115 stores initial print setting information of the image forming apparatus 1, machine setting information such as process control parameters, user setting values, pattern data for image adjustment, image adjustment results, operation time, number of printed sheets, and the like. ing.

  The control unit 113 can read non-volatile data in the non-volatile memory 115 and can write desired data in the non-volatile memory 115. The control unit 113 can control the operation of each unit of the image forming apparatus 1 in accordance with the machine setting information, the print setting information, and the like, and can perform an image adjustment operation. Further, the control unit 113 can manage the machine state of the image forming apparatus 1 and can grasp a change in the machine state of the image forming apparatus. The control unit 113 performs image formation control such as job management control based on image data stored in the compression memory 120 and data related to jobs.

The scanner unit 130 includes a CCD 131 that performs optical reading and a scanner control unit 132 that controls the entire scanner unit 130. The scanner control unit 132 is connected to the control unit 113 so that serial communication is possible, and the scanner unit 130 is controlled by the control unit 113. The CCD 131 is connected to a reading processing unit 116 that processes image data read by the CCD 131, and the reading processing unit 116 is connected to a DRAM control IC 111 so as to be controllable.
Further, in order to read a plurality of originals by the scanner unit 130, an unillustrated casting type automatic original feeder (ADF) is provided.

The operation unit 140 includes an LCD 141 configured as a touch panel that serves as both a display unit and an operation unit, and an operation unit control unit 142 that controls the entire operation unit. The operation unit control unit 142 is serially connected to the control unit 113. It is connected so that it can communicate.
In the operation unit 140, under the control of the control unit 113, input of machine settings such as output condition setting and operation control condition in the image forming apparatus 1 and setting of paper information (size, paper type) of each paper feed tray are performed by the LCD 141. Input, setting of the start time of image adjustment, display of setting contents, display of desired information such as warnings, and the like are possible.

The DRAM control IC 111 is connected to a compression IC 118 that compresses image data and a decompression IC 125 that decompresses the compressed image data. The writing processing unit 126 is connected to the image forming unit 10 including the LD 152 of the printer unit 150 (corresponding to the writing unit 13 of FIG. 1) and the like, and performs processing of writing data used for the operation of the LD 152.
The printer unit 150 includes, in addition to the image forming unit 10, a paper transport unit including a paper feed tray 21 and a transport path 22.

  The printer unit 150 includes a printer control unit 151 that controls the entire printer unit 150 (paper feeding, image formation, paper discharge, post-processing, and the like). The printer control unit 151 is connected to the control unit 113 described above. Has been. The printer control unit 151 operates according to a control command from the control unit 113 to control the printer unit 150. The post-processing device (FNS unit) 170 is controlled via the printer control unit 151. The printer unit 150 is controlled by the control unit 113, and the control unit 113 controls conveyance of paper and image formation.

  A DRAM control IC 161 of the image processing unit (print & scanner controller) 160 is connected to the PCI bus 112 to which the DRAM control IC 111 is connected. When the image forming apparatus 1 is used as a network printer or a network scanner, the image processing unit (print & scanner controller) 160 receives image data from an external device connected to the LAN 3, such as an external device (PC) 2. The image data is received by the image forming apparatus 1 or the image data acquired by the scanner unit 130 is transmitted to an external device (PC) 2 connected to the LAN 3.

  In the image processing unit (print & scanner controller) 160, an image memory 162 composed of a DRAM or the like is connected to the DRAM control IC 161. In the image processing unit (print & scanner controller) 160, the DRAM control IC 161, a controller control CPU 163 for controlling the entire image processing unit (print & scanner controller) 160, and a LAN interface 165 are connected to a common bus. . The LAN interface 165 is connected to the LAN 3.

Next, the basic operation of the image forming apparatus 1 will be described.
First, a procedure for accumulating image data in the image forming apparatus 1 will be described.
When the scanner unit 130 reads an image of a document and generates image data, the scanner unit 130 optically reads the document image from the document by the CCD 131. At this time, the operation of the CCD 131 is controlled by the scanner control unit 132 that receives a command from the control unit 113. The image read by the CCD 131 is subjected to data processing by the reading processing unit 116, and the image data subjected to the data processing is compressed by the compression IC 118 by a predetermined method and stored in the compression memory 120 via the DRAM control IC 111. The image data stored in the compression memory 120 can be managed as a job by the control unit 113.

  When acquiring image data from the outside, for example, image data transmitted from the external device (PC) 2 or the like through the LAN 3 is stored in the image memory 162 by the DRAM control IC 161 via the LAN interface 165. Data in the image memory 162 is temporarily stored in the page memory 121 via the DRAM control IC 161, the PCI bus 112, and the DRAM control IC 111. Data stored in the page memory 121 is sequentially sent to the compression IC 118 via the DRAM control IC 111 and compressed, stored in the compression memory 120 via the DRAM control IC 111, and managed by the control unit 113 as described above. Made.

  When the image forming apparatus 1 outputs an image, that is, when it is used as a copying machine or a printer, the image data stored in the compression memory 120 is sent to the decompression IC 125 via the DRAM control IC 111 to decompress and decompress the data. The transmitted data is sent to the write processing unit 126, and the LD 152 performs writing on the photoconductor 11.

In the printer unit 150, each unit is controlled by the printer control unit 151 that has received a command from the control unit 113. In the image forming unit 10, the intermediate transfer belt 16 is crimped to the photoconductor 11 in a five-color crimping, four-color crimping, or monochrome crimping state by a crimping mechanism 16 </ b> A controlled by the control unit 113 via the printer control unit 151 according to the printing conditions. doing.
The toner image written on the photoconductor 11 is transferred to the intermediate transfer belt 16, and then transferred to the paper supplied by the paper feed tray 21, and fixed by the fixing device 19. The sheet is conveyed from the sheet feeding tray 21 through the conveyance path 22 and the sheet is brought into contact with the registration roller 23 to correct skew. Thereafter, the sheet is conveyed to the image forming unit 10 and image formation is performed as described above.

The paper on which the image has been formed is transported to a post-processing device (FNS unit) 170 via a transport path 22 via a fixing transport roller. When post-processing is designated, post-processing is performed and post-processing is not required The paper is discharged as it is to the paper discharge tray. When there are a plurality of reserved jobs, the image output is sequentially performed according to the setting order.
In the photoreceptor 11, after the toner image is transferred to the intermediate transfer belt 16, the residual toner is removed by the cleaning unit 15. Similarly, in the intermediate transfer belt 16, after the toner image is transferred onto the paper, the residual toner is removed by the cleaning unit 17.

Next, an image adjustment operation executed by the control unit 113 will be described. In the following image adjustment operation, color misregistration correction will be described. The image adjustment operation is not limited to color misregistration correction. For example, color tone adjustment may be performed, or a plurality of image adjustment operations including color misregistration correction may be performed.
In the color misregistration correction, three rows of images are formed on the intermediate transfer belt 16 along the main scanning direction based on the color registration pattern for color misregistration for each pressure-bonded state, and the sub-scanning is performed in the vicinity of the intermediate transfer belt 16. The color resist pattern of each color is read by sensors 40, 41, and 42 provided along the direction. The pattern shape is not particularly limited, and a different pattern or the like may be used for each sensor. Further, the number of sensors is not particularly limited.

FIG. 4 shows an intermediate transfer belt 16 that performs image adjustment in a five-color press-bonded state using CL, Y, M, C, and K. FIG. 5 shows a four-color press-bonded state using Y, M, C, and K. 2 shows an intermediate transfer belt 16 that performs the image adjustment.
In the pattern shown in FIG. 4, for example, the deviation amounts of Y, M, C, and CL with respect to K are calculated from the results read by the sensors 40, 41, and 42, and the correction amount for color registration correction is obtained as an adjustment result. Give feedback to. The adjustment result is stored in a readable manner in the nonvolatile memory 115 or the like in association with the five-color press-bonded state. In the pattern shown in FIG. 5, for example, the deviation amounts of Y, M, and C with respect to K are calculated from the results read by the sensors 40, 41, and 42, and the adjustment results are fed back to the correction amount of color registration correction. multiply. The adjustment result is stored in a readable manner in the nonvolatile memory 115 or the like in association with the four-color press-bonded state.
In this embodiment, the adjustment result is that the resist of each color is measured with a specific color as a reference. However, the method is not particularly limited, and the resist correction amount is obtained without providing a color reference. There may be.

  The timing of the image adjustment operation is not limited to a specific case. For example, the image adjustment operation can be performed every predetermined operation time, every predetermined number of printed sheets, and the operation timing can be set according to an arbitrary setting of the operator. The image adjustment may be performed immediately according to an instruction from the operator. The operation time may be determined in advance by initial setting, and may be further set by the operator through the operation unit 140 or the setting content can be changed.

  In addition, when performing image adjustment, it is not necessary to perform image adjustment for all of the color materials to be used. For example, a color material with a low degree of requirement for image position deviation, such as CL ( For clear toner, etc., a pattern for image adjustment may not be formed. As a result, the amount of toner used for image adjustment can be reduced. Further, the color material to be excluded is not limited to CL (clear toner), and other color materials may be used.

That is, the problem of the present invention is that the shift amount calculated from the color resist pattern is different between the four-color crimping and the five-color crimping. The tension of the intermediate transfer belt changes and the amount of deviation varies depending on whether or not the photoconductor of the special color toner is pressed.
If the pressure-bonding state is switched during printing and printing is continued with a parameter in which the amount of deviation is corrected, the color will be displaced. However, if the color registration correction is performed after switching the crimping state during printing, the printing will be delayed, so there will be no discomfort for the user. The correction parameters in each crimping state are held, and only the correction parameters are switched when the crimping state is switched.

The correction parameter switching timing as the image adjustment result will be described with reference to the flowchart of FIG. The following procedure is executed under the control of the control unit 113.
With the start of image formation, it is determined whether the print instruction is a color print instruction (step s1).
If it is not a color print instruction, the instruction is waited (step s1, none). If it is a color print instruction (Yes in step s1), it is determined whether or not clear toner is used (step s2).

If the clear toner is not used (step s2 is not performed), the pressure bonding mechanism is operated to bring the four color pressure bonding state (step s3), and the correction parameter is switched to the four color color registration correction parameter (step s4). The correction parameters are stored in the nonvolatile memory 115, and necessary correction parameters are read out, stored in the RAM of the control unit 113, and used for control.
When the clear toner is used (step s2), the pressure-bonding mechanism is operated to make the five-color pressure-bonding state (step s5), and the correction parameter is switched to the five-color color registration correction parameter (step s6). The correction parameters are stored in the nonvolatile memory 115, and necessary correction parameters are read out, stored in the RAM of the control unit 113, and used for control.
As described above, only some of the used color materials may be switched to the color registration correction parameters.

  In addition, when the user performs image adjustment through the operation unit 140, or when a predetermined number of sheets or a predetermined time elapses, the color registration correction in each press-bonding state is performed at the same time, so that the machine stop timing is reduced to one place. It can be aggregated and not distributed.

The procedure of the image adjustment operation will be described based on the flowchart of FIG. The following procedure is executed under the control of the control unit 113.
It is determined whether there has been a panel instruction for an image adjustment instruction through the operation unit 140 (step s10). If there is a panel instruction (Yes at step s10), a four-color press-bonded state is set (step s12). If there is no panel instruction, it is determined whether the predetermined operating time has elapsed or the predetermined number of sheets has elapsed (step s11). If neither the predetermined operating time has elapsed nor the predetermined number of sheets has elapsed, the process is terminated (step s11, no progress).
If the predetermined operating time has elapsed or the predetermined number of sheets have elapsed (step s11, elapses), a four-color press-bonded state is set (step s12).

After step s12, color resist correction for four colors is performed (step s13), and then a five-color press-bonding state is set (step s14), and color resist correction for five colors is performed (step s15), and the process ends. The color registration correction results are stored in the nonvolatile memory 115 or the like in association with the crimped state.
The color registration correction for four colors performs registration correction with four colors of YMCK, and the color registration correction for five colors performs registration correction by adding CL (clear) to YMCK.
Further, as described above, resist correction may be performed for some of the color materials in the press-bonded state. For example, it is also possible to perform resist correction only with four colors of YMCK by five-color pressure bonding and four-color pressure bonding.

FIG. 8 shows an operation screen 1400 for setting the timing for performing the image adjustment operation, which is displayed on the LCD 141 so as to be operable.
The operation screen 1400 has an elapsed time button 1410 for setting an elapsed time as a timing for performing an image adjustment operation, and a set time in the time input field 1411 can be input according to the push button of the button. The set time can be input using the numeric keypad 1460. In the time input field 1411, an initial setting time may be set.

  Further, the operation screen 1400 has a number-by-number button 1420 for setting a predetermined number as the timing for performing the image adjustment operation, and a predetermined number is input to the number input field 1421 according to the push button of the button. Can do. The predetermined number of sheets can be input using the numeric keypad 1460. In the number input field 1421, an initial set number may be set.

Further, the operation screen 1400 has an arbitrary setting button 1430 that is set by the operator as the timing for performing the image adjustment operation. In this example, the setting can be made according to the contents provided in the list column 1431. When it is necessary to input a specific numerical value, an input field may be displayed so that setting can be performed using the numeric keypad 1460. As an arbitrary setting, it can perform by setting, such as a date, for example.
The operation screen 1400 is provided with an immediate button 1440 for instructing to immediately perform the image adjustment operation.
The operation screen 1400 is provided with an execution button 1450 and a cancel button 1451. When the execution button 1450 is pressed, the setting content is confirmed, and an image adjustment operation is performed according to the setting content. When the cancel button 1451 is pressed, the setting contents are canceled.

Next, in image formation, for example, in the case of frequent switching of the crimping state such as five-color printing, four-color printing, and five-color printing, the lifetime is sacrificed in order to reduce the downtime of switching the crimping state. However, it is possible to provide a mode for performing five-color printing, four-color printing, and five-color printing with five-color pressure bonding.
In this case, since the four-color printing performed between them is a five-color pressure bonding, the color resist correction parameters are the same as those for the five-color pressure bonding.

Hereinafter, a processing procedure in a case where the use or non-use of some color materials is continued between a plurality of jobs will be described based on the flowchart of FIG. The following procedure is executed under the control of the control unit 113.
It is determined whether or not the clear toner is used with the start of the job (step s20).
When clear toner is not used (step s20, not), the intermediate transfer belt 16 is pressure-bonded to the Y, M, C, and K photoconductors 11, and the CL photoconductor 11 is separated from the intermediate transfer belt in a four-color pressure-bonded state. (Step s21) Switching to the four-color color resist correction parameter (Step s22), four-color printing by four-color pressure bonding is performed (Step s23).

  Next, it is determined whether the printing is finished (step s24). If the printing is finished (step s24, finished), the process is finished. If printing is not finished (step s24, not finished), it is determined whether the next paper clear toner is used (step s25).

If the next sheet does not use clear toner (NO in step s25), the process returns to step s23 to continue the process. If the next sheet uses clear toner (step s25), the process proceeds to step s26 where the five-color pressure bonding is performed.
If clear toner is used in step s20 (step s20), the process proceeds to step s26.

  In step s26, the CL, Y, M, C, and K photoconductors 11 are all crimped to the intermediate transfer belt 16 (step s26), and the five-color color registration correction parameters are switched (step s27). Five-color printing is performed in the crimped state (step s28).

  Next, it is determined whether the printing has been completed (step s29). If the printing has been completed (step s29, end), the process ends. If printing is not finished (step s29, not finished), it is determined whether or not clear toner is used for the next sheet (step s30).

If the next sheet uses clear toner (step s30), the process returns to the procedure for performing the five-color printing in the five-color press-bonded state in step s28 and the processing is continued.
When the clear toner is not used on the next sheet (step s30, not), it is determined whether the clear toner is used on the next sheet (step s31). When the clear toner is used on the next next sheet (step s31), the four-color printing is performed on the next sheet in the five-color press-bonded state (step s32), and the determination of whether the printing is finished is repeated in step s29. At this time, since the five-color color registration correction parameter is used, no color misregistration occurs even in four-color printing.
When the clear toner is not used for the next next sheet (step s31, not), the process returns to step s21 to continue the four-color pressure bonding process.

  According to the above, when a part of the color material is used, unused, or continuously used, image formation can be performed without changing the pressure-bonding state (for example, five-color pressure bonding), and a decrease in productivity is avoided. be able to. Note that the above procedure can be executed not only when printing paper within a job but also when printing across multiple jobs.

  As mentioned above, although this invention was demonstrated based on the said embodiment, unless it deviates from the scope of the present invention, an appropriate change is possible, and what was changed is also within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 1A Image forming apparatus main body 10 Image forming part 11 Photoconductor 16 Intermediate transfer belt 16A Pressure bonding mechanism 18 Secondary transfer roller 113 Control part 115 Non-volatile memory 140 Operation part 1400 Operation screen

Claims (18)

An image forming unit having a crimping mechanism having a plurality of crimping states depending on printing conditions;
A control unit that controls the image forming unit and performs image adjustment in the plurality of pressure-bonding states;
A storage unit that holds the adjustment result by the image adjustment for each crimping state,
The control unit reads an adjustment result corresponding to the crimping state from the storage unit when the crimping state is switched, and performs image formation based on the adjustment result.   The image forming apparatus according to claim 1, wherein the image adjustment includes color misregistration correction.   The image forming apparatus according to claim 1, wherein the plurality of pressure-bonding states are a combination of different color material pressure bonding.   4. The image forming apparatus according to claim 3, wherein the plurality of crimping states are a four-color crimping of yellow, cyan, magenta, and black and a five-color crimping in which one color is added to the four-color crimping.   When executing a job, the control unit performs the image formation in a pressure-bonded state using the color material when job use, job nonuse, and job use of some color material are repeatedly executed. The image forming apparatus according to claim 3 or 4.   The control unit performs image formation based on an image adjustment result with respect to the pressure-bonded state when image formation is performed using a part of color materials among the color materials causing the pressure-bonded state. The image forming apparatus according to claim 3.   The said control part performs image adjustment only about a part of color material among the color materials which have brought about the said crimping | compression-bonding state in the said image adjustment. Image forming apparatus.   The image forming apparatus according to claim 1, wherein the control unit continuously performs image adjustment in the plurality of press-bonded states at the same time.   9. The image forming apparatus according to claim 1, wherein the control unit performs the image adjustment every time a predetermined number of sheets are printed, every time a predetermined operation time elapses, or according to user settings. An image forming unit having a crimping mechanism having a plurality of crimping states according to printing conditions, a control unit for controlling the image forming unit and performing image adjustment in the plurality of crimping states, and an adjustment result by the image adjustment for each crimping state. An image forming control method for an image forming apparatus, comprising:
An image formation control method, comprising: reading an adjustment result corresponding to the pressure-bonding state from the storage unit and performing image formation based on the adjustment result when the pressure-bonding state is switched.   The image formation control method according to claim 10, wherein the image adjustment includes color misregistration correction.   The image forming control method according to claim 10, wherein the plurality of pressure-bonding states are a combination of different color material pressure bonding.   13. The image forming control method according to claim 12, wherein the plurality of crimping states are a four-color crimping of yellow, cyan, magenta, and black and a five-color crimping by adding one color to the four-color crimping. .   13. The image formation is performed in a pressure-bonded state using the color material when the job execution, the job non-use, and the job use are partially executed when executing a job. Or the image formation control method of 13.   The image forming is performed based on a result of image adjustment with respect to the pressure-bonded state when image formation is performed using a part of the color materials that cause the pressure-bonded state. The image formation control method according to any one of the above.   The image formation control method according to any one of claims 12 to 15, wherein, in the image adjustment, image adjustment is performed only for some of the color materials that bring about the press-bonded state. .   The image formation control method according to any one of claims 10 to 16, wherein image adjustment in the plurality of press-bonded states is continuously performed simultaneously.   The image forming control method according to claim 10, wherein the image adjustment is performed every time a predetermined number of sheets are printed, every elapse of a predetermined operation time, or according to a setting content of a user.

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