JP2013120240A - Image forming device and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device including a plurality of image forming sections for four colors, so that some of them form a toner image of the same color, to respond to user request in detail for forming a color image, and to provide an image forming method.SOLUTION: The image forming device includes: an image processing part 110 for generating image data of plural different colors; an image forming part 104 that forms toner images corresponding to each of the colors of the generated image data and has a plurality of cartridges, some of which form a toner image of the same color; and setting part 111 that sets different image forming conditions for the cartridges in the image forming part 104, which form the toner image of the same color. The cartridges which form the toner image of the same color perform image formation processing respectively for each of a plurality of image regions.

Description

  The present invention relates to an image forming apparatus such as an electrophotographic copying machine, a printer, and a facsimile, and an image forming method.

Conventionally, in an image forming apparatus such as a copying machine, a printer, and a facsimile, an image forming process using an electrophotographic method is used for a recording medium such as paper. In the electrophotographic image forming process, toner is attached to the electrostatic latent image formed on the surface of the photoconductor for development, the developed toner image is transferred to a sheet, and the toner image is fixed on the sheet by heating. Then, an image forming process is performed.
When forming a color image in an electrophotographic image forming apparatus, a paper is wound around a transfer drum, and toner images of different colors are formed on the surface of the photosensitive drum. There is a transfer method (transfer drum method). In addition, a system such as a system (intermediate transfer system) in which a toner image is temporarily transferred from a plurality of image forming units to an intermediate transfer belt to form a color toner image, and the formed color toner image is transferred to paper. Has been proposed.
An image forming apparatus for forming a color image generally includes an image forming unit for black toner that records a monochrome image and an image forming unit for three color toners, cyan, magenta, and yellow, for recording a color image. When the image data to be formed is a monochrome image made up of characters or the like, the image forming process is performed only with the black toner image forming unit. When the image data is a color image such as a photograph, the color of the color image Based on the separation data and the like, the color toner image forming unit forms an image of each color and superimposes them to perform color image image forming processing.

  It has been proposed to provide an image forming unit for forming an image of a special color or the like in addition to the image forming unit of toner of four colors of C (cyan) M (magenta) Y (yellow) K (black). . For example, in Patent Document 1, in order to be able to print with at least one special color other than four colors of cyan, magenta, yellow, and black, command analysis of CMYK plate and transparent toner plate is performed and command analysis is performed. The CMYK plane image data is generated based on the result of the above, and the transparent toner attribute obtained by analyzing the transparent toner plane is embedded in the attribute flag added for each pixel of the generated CMYK plane image data. An apparatus for performing an image forming process is described. In Patent Document 2, color design using a recording medium having a desired color and white toner is performed to determine gradation correction and an appropriate toner application amount according to the recording medium. A color image that is placed on the bottom layer, blocks the color of the recording medium with white toner, draws the image, and prints toner other than the white toner on it to produce the color of the recording medium and the toner other than the white toner. An apparatus for forming the is described.

In the apparatus described in the above-mentioned patent document, an image is formed with a transparent toner or a white toner in addition to the four colors CMYK. However, the toner other than the four colors has an additional effect on the formation of a color image. Although effective, the color forming process itself is not directly related, and thus there is a problem that it is difficult to precisely respond to the user's request for the color forming process.
In view of this, the present invention includes a plurality of image forming units that form toner images of the same color among some of the four color image forming units, so that the user's request for color image forming processing can be precisely met. An object is to provide an image forming apparatus and an image forming method.

  An image forming apparatus according to the present invention forms a toner image corresponding to a plurality of different colors and superimposes the toner images to form a color image on a recording medium. A plurality of image forming means for forming a toner image corresponding to each color of the generated image data and forming a toner image of a part of the same color; and the same color among the image forming means Setting processing means for setting different image forming conditions for the image forming means for forming the toner image.

  According to the present invention, by setting image forming conditions for a plurality of image forming units that form toner images of the same color based on a user's request, it is possible to finely meet a user's request for color image forming processing.

It is a schematic block diagram regarding the image forming apparatus according to the present embodiment. 1 is a block configuration diagram relating to an image forming apparatus according to an exemplary embodiment. It is a block block diagram regarding the color separation process in an image process part. It is explanatory drawing regarding an image formation process. It is a processing flow regarding a mode selection process. It is a schematic block diagram regarding the modification of this embodiment. FIG. 10 is an explanatory diagram relating to an image forming process in a case where a user sets an image area in which a plurality of cartridges of the same color forms an image. FIG. 10 is an explanatory diagram relating to an image forming process when a user sets a page on which an image is formed by a plurality of cartridges of the same color.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram relating to an image forming apparatus according to the present embodiment, and schematically shows a main part thereof.
As illustrated, the image forming apparatus 1 includes a paper feed tray 4 that can store a plurality of recording papers P, a transfer belt 5 disposed above the paper feed tray 4, and a plurality of cartridges disposed along the transfer belt 5. (Electrophotographic process part) 6K, 6M, 6C, 6Y, 6X, the exposure device 11 arranged above them, and the fixing device 20 provided in the conveyance path 40 of the recording paper P are provided. Here, the color component colors are black (K), magenta (M), cyan (C), and yellow (Y), and there are four color cartridges 6K, 6M, 6C, and 6Y. A color toner image is generated. The cartridge 6X is a cartridge having the same toner as any one of black (K), magenta (M), cyan (C), and yellow (Y). The cartridge 6X may be a cartridge having a color other than four colors, such as a transparent color and a fluorescent color.

A plurality of recording papers P are stored in the paper feed tray 4 in a stacked state, and are fed to the top by a paper feed roller 2 that is driven to rotate in a predetermined direction (counterclockwise in the figure) during image formation. The paper is fed out toward the conveyance path 40 in order from the one located. The sent recording paper P is transported along a transport path 40 by a plurality of rollers 3, 7, 16, 21, 22, 18 and the like, and is discharged outside the apparatus.
The transfer belt 5 is an endless belt that is an intermediate transfer body for transferring the toner images transferred from the cartridges 6K, 6M, 6C, 6Y, and 6X to the recording paper P, and includes a rotatable secondary transfer driving roller 7 and It is wound around a transfer belt tension roller 8. The secondary transfer drive roller 7 is rotationally driven by a drive source (not shown) such as a motor, and the transfer belt tension roller 8 that rotates following the transfer belt 5 is stretched across the transfer belt 5 so as to be opposed to each other in the vertical direction. Supports to extend. Accordingly, each of these rollers 7 and 8 and a driving source constitute a driving means for rotating and moving the transfer belt 5, and the transfer belt 5 is circulated between the rollers 7 and 8 in a predetermined direction (counterclockwise indicated by an arrow in the drawing). To rotate.

The cartridges 6K, 6M, 6C, 6Y, and 6X are arranged on the upper surface side of the transfer belt 5 at predetermined intervals in order from the upstream along the rotation direction. As will be described later, the cartridges 6K, 6M, 6C, 6Y, and 6X are so-called AIOs in which a photosensitive unit including a photosensitive drum, a toner filling unit filled with toner, a developing device, a cleaning system, and the like are integrated. An (All In One) cartridge that contains toner of different colors according to the color of the image to be formed. Also, here, in order from the upstream side of the transfer belt 5, a first cartridge 6K that forms a black (K) image, a second cartridge 6M that forms a magenta (M) image, and a cyan (C) image. The third cartridge 6C that forms the image, the fourth cartridge 6Y that forms the yellow (Y) image, and the fifth cartridge 6X that forms an image of any one of the four colors are provided along the transfer belt 5. Arranged in a row.
The exposure unit 11 applies laser beams 14K, 14M, 14C, 14Y, and 14X (indicated by dotted lines in the drawing) corresponding to image colors formed by the cartridges 6K, 6M, 6C, 6Y, and 6X to the cartridges 6K. , 6M, 6C, 6Y, and 6X. Therefore, the exposure device 11 includes a plurality of (here, five) light sources (not shown) that generate the laser beams 14K, 14M, 14C, 14Y, and 14X, and the like, and the laser beams 14K, 14M, 14C, and 14Y. , 14X are irradiated to the photosensitive members 9K, 9M, 9C, 9Y, and 9X of the respective cartridges 6K, 6M, 6C, 6Y, and 6X from the lower surface side in the downward direction.

Next, the cartridges 6K, 6M, 6C, 6Y, and 6X will be described. These have the same internal configuration except that the colors of the toner images to be formed are different, and are similarly configured. Therefore, here, the first cartridge 6K (black image forming unit) located on the most upstream side (right side in the drawing) of the transfer belt 5 is described as an example, and other colors for forming images of other colors are described. Description of the cartridges 6M, 6C, 6Y, and 6X is omitted. In addition, for each component of these cartridges 6K, 6M, 6C, 6Y, and 6X, the same component is given the same number, and thereafter, the above-mentioned corresponding to each cartridge 6K, 6M, 6C, 6Y, and 6X. These are distinguished by adding the symbols K, M, C, Y, and X.
The first cartridge 6K (image forming unit) includes a photoconductor 9K that is a photoconductor drum provided to face the upper surface of the transfer belt 5, and a charger 10K, a developer 12K, and a cleaner disposed around the photoconductor 9K. It is composed of a blade (photoconductor cleaner) 13K and the like.
At the time of image formation, the outer peripheral surface of the photoconductor 9K is uniformly charged by the charger 10K in the dark, and is then exposed by the laser light 14K corresponding to the black image from the above-described exposure device 11, and the outer peripheral surface ( An electrostatic latent image is formed on the photosensitive surface. At that time, the exposure unit 11 controls the light emission of the light source of the laser beam 14K in accordance with the line image signal in the main scanning direction, for example, so that the generated light is used as a scanning beam at a predetermined cycle. Project to. At the same time, the photosensitive member 9K is moved (rotated) in the sub-scanning direction crossing the main scanning direction (the control in the sub-scanning direction is performed by the control of a motor (not shown) that rotates the photosensitive member 9K). Scan exposure of a two-dimensional image is performed.
The developing device 12K develops the electrostatic latent image on the photoconductor 9K and visualizes it with black toner, and forms a black toner image on the photoconductor 9K. Thereafter, the toner image is transferred to the transfer belt 5 by the action of the primary transfer roller 15K disposed opposite to the photoconductor 9K across the transfer belt 5 at the position where the photoconductor 9K and the transfer belt 5 are in contact (primary transfer position). Transcribed above. As a result, a monochrome image is formed on the transfer belt 5 with black toner. On the other hand, after the toner image transfer is completed, unnecessary toner remaining on the outer peripheral surface is wiped away by the cleaner blade 13K and cleaned, and the photoconductor 9K waits for the next image formation. The cleaned residual toner is collected and discharged into the waste toner box 50.

The transfer belt 5 onto which the black toner image has been transferred by the first cartridge 6K through the above process is rotationally driven by the rotation of the secondary transfer driving roller 7, and the portion (surface) on which the toner image is formed. It moves to the next second cartridge 6M located on the downstream side in the rotation direction, and conveys the toner image to its lower position. In the second cartridge 6M, a magenta toner image is formed on the photoconductor 9M by a process similar to the image forming process in the first cartridge 6K, and the black toner image formed on the transfer belt 5 is formed on the transfer belt 5. The toner image is transferred onto the toner image.
Subsequently, the transfer belt 5 moves in order to the third cartridge 6C, the fourth cartridge 6Y, and the fifth cartridge 6X located further downstream, and on the photoreceptor 9C by the same processes and operations as before. The cyan toner image formed on the photosensitive member 9Y, the yellow toner image formed on the photosensitive member 9Y, and the toner image of any one of the four colors formed on the photosensitive member 9X are transferred onto the transfer belt 5. The toner images are sequentially transferred in a superimposed manner. In this way, after the toner images of a plurality of colors are transferred and superimposed on the transfer belt 5 to form a full-color superimposed image (color image), the color toner image forming portion of the transfer belt 5 It moves to the position of the secondary transfer roller 16 with the rotation.
Here, when forming an image of only black when forming an image, the second to fifth cartridges 6M, 6C, 6Y, 6X are not operated, and the corresponding primary transfer rollers 15M, 15C, 15Y, 15X are respectively set. Retraction is performed at positions away from the photoconductors 9M, 9C, 9Y, and 9X, and only the black image forming process by the first cartridge 6K is executed.

Further, in synchronization with the movement (rotation) of the transfer belt 5 described above, the conveying operation of the recording paper P along the conveying path 40 is also started. At that time, first, the recording paper P stored in the paper feed tray 4 is sequentially sent out from the uppermost position by the rotation of the paper feed roller 2, and the front side of the secondary transfer roller 16 at the position of the registration roller 3. Stand by (upstream in the transport direction). The rotation of the registration roller 3 is started when the toner image conveyed by the movement of the transfer belt 5 and the position of the recording paper P are positioned on the secondary transfer roller 16 (between the opposing secondary transfer drive roller 7). The registration roller 3 is rotated counterclockwise by a driving means (not shown), and the recording paper P is fed out.
The recording paper P delivered by the registration roller 3 is conveyed toward the downstream side of the conveyance path 40 as the toner image on the transfer belt 5 is transferred by the secondary transfer roller 16 and is moved. Subsequently, the recording paper P is heated and pressed through a nip formed between a fixing roller 21 and a pressure roller 22 which are a pair of rotating bodies of the fixing device 20, and the toner image is heated. Heat-fixed by pressure. Thereafter, the recording paper P is discharged out of the image forming apparatus 1 (here, at the top) by a paper discharge roller 18 that is rotationally driven in a predetermined direction (here, clockwise) by a driving unit (not shown). .
On the other hand, when performing double-sided printing on the recording paper P, before the recording paper P passes through the paper discharge roller 18, the paper discharge roller 18 is rotationally driven in the reverse direction (here, counterclockwise) to perform recording. The sheet P is sent out to the duplex conveyance path 41. In the double-sided conveyance path 41, the recording paper P is conveyed again to the registration roller 3 via the rotating double-sided roller 19. The recording paper P that has reached the registration roller 3 is fed again along the conveyance path 40 by the registration roller 3, and is transferred by the secondary transfer roller 16 to the surface opposite to the surface on which the image has been previously formed. The toner image is transferred from. Thereafter, a new toner image is heated and fixed by the fixing device 20 in the same manner as described above, and the recording paper P is discharged to the outside of the image forming apparatus 1 by the discharge roller 18.
The image forming apparatus 1 includes a known document reading unit 30 at an upper portion thereof, reads a document by an optical reading unit while conveying the document by a document transport mechanism, and transmits a read signal to the above-described image forming unit. ing.

FIG. 2 is a block diagram of the image forming apparatus according to the present embodiment. The image forming apparatus 1 includes a control unit 100 that controls the operation of the entire apparatus, an image reading unit 101 that generates image data based on a reading signal from the document reading unit 30, a user's operation to input data and a message. An operation display unit 102 for displaying the image, a program and setting data necessary for operation control, a storage unit 103 for storing image data necessary for image formation, and an image based on the image data stored in the storage unit 103 An image forming unit 104 that performs a forming process is provided.
The image forming apparatus is connected to a PC 106 that is an information processing apparatus via an external I / F unit 105 that functions as an interface. Then, based on a command from the PC 106, document data, image data, and the like created by the PC 106 are received and image forming processing is performed. The image forming apparatus 1 transmits and receives image data and the like to and from the FAX 108 connected to the communication line via the line I / F unit 107 functioning as an interface, and performs image forming processing on the received image data and the like. .

The control unit 100 includes an image processing unit 110, a setting processing unit 111, and a selection processing unit 112. The image processing unit 110 processes the image data received from the image reading unit 101 and stores it in the storage unit 103. As image processing, for example, correction processing such as mechanical deviation in the document reading unit 30, image separation processing for separating an image portion and a text portion from the corrected image data, halftone processing such as color conversion and total amount regulation Processing such as editing processing such as zooming and rotation is performed.
The setting processing unit 111 performs settings necessary for the image forming process of the image forming unit 104 and sets the developing conditions of the first to fifth cartridges 6K, 6M, 6C, 6Y, and 6X. Of the four color cartridges 6K, 6M, 6C, and 6Y, the same color as the fifth cartridge 6X is set so that the developing conditions are different between the same color cartridges. The toner density of the cartridge 6X is set to be low.
The selection processing unit 112 performs selection processing of the first to fifth cartridges 6K, 6M, 6C, 6Y, and 6X. For the fifth cartridge 6X and a cartridge of the same color as the fifth cartridge 6X, a cartridge corresponding to a plurality of image areas divided in a page on which image formation processing is performed is selected, or one cartridge is selected for each page on which image formation processing is performed. select. Also, one of the cartridges is selected in accordance with the setting conditions such as the toner saving mode.

FIG. 3 is a block configuration diagram relating to color separation processing in the image processing unit 110. The image reading unit 101 inputs image data read by the document reading unit 30. In this example, RGB data that is color separation data relating to image data is input. In addition to the read signal from the document reading unit 30, RGB data included in the print data transmitted from the PC 106 can also be input. In the case of an input signal other than RGB data (eg, L * a * b * data), it can be converted into RGB data and input.
The image feature amount extraction unit 201 performs a feature amount extraction process on the image area of the input image data based on a predetermined condition. Then, based on the result of the feature amount extraction processing, together with the RGB data, X data necessary for image formation with the fifth cartridge 6X described above is output. For example, as shown in FIG. 4A, a feature amount of image data is extracted to specify a region including a design and a region containing only characters, and the region including a design is determined as a region in which image quality is important. Then, it is determined that the character-only area is an area where the image quality is not important, and these determination results are output as X data.
The filter processing unit 202 performs a filtering process on the RGB data and the X data input from the image feature amount extraction unit 201, and is unified with characteristics predetermined according to a given mode such as sharpness for each pixel. The processed RGB data and X data are output to the color correction processing unit 203.

The color correction processing unit 203 converts the input RGB data into CMYK data that is a color space format for forming an image, and outputs the converted data to the γ conversion processing unit 204. The input X data is also converted as necessary and output to the γ conversion processing unit 204.
The γ conversion processing unit 204 adjusts the density of the input RGB data and X data when forming an image for each pixel, and outputs the result to the halftone processing unit 205. The halftone processing unit 205 performs gradation processing that matches a given characteristic, for example, dither processing or error diffusion processing. In this example, the halftone processing unit 205 separates the K data into K1 data used for image formation of the first cartridge 6K and K2 data used for image formation of the fifth cartridge 6X based on the X data. I do. By performing such processing, as shown in FIG. 4B, the image formation is performed with the first cartridge 6K in the above-described region where the image quality is important, and the fifth cartridge 6X is performed with respect to the region where the image quality is not important. Image formation can be performed. For this reason, it is possible to reduce the toner consumption as a whole by filling the fifth cartridge 6X with black toner and reducing the density of toner in an area where image quality is not important. In the fifth cartridge 6X, the toner density can be reduced by adjusting the developing conditions (developing voltage, etc.) with the toner, for example. In this way, the first to fourth cartridges 6K, 6M, 6C, and 6Y form an image with an emphasis on image quality, and the fifth cartridge 6X forms an image with a low toner density and superimposes the formed images. As a result, it is possible to output a printed matter with reduced toner consumption without degrading the image quality (FIG. 4C).
In this way, by providing a cartridge of the same color as any of the four color cartridges, it is possible to form an image by changing the conditions of a plurality of cartridges of the same color, and respond precisely to the user's request. It becomes possible.
In the example described above, feature amounts are extracted based on input RGB data to separate image areas, and image formation processing is performed using a plurality of cartridges of the same color. It is also possible to select different cartridges when image forming processing is performed in the normal mode and the toner saving mode with different development conditions.
FIG. 5 is a process flow relating to the mode selection process. In this example, the first cartridge 6K and the fifth cartridge 6X are filled with the same color toner, and the fifth cartridge 6X is set to be developed with toner saving. Then, it is checked whether or not the toner saving mode is selected (S101). If the toner saving mode is selected (YES in S101), the second to fifth cartridges 6M, 6C, 6Y, and 6X are selected. (S102) An image forming process is performed (S104). When the toner saving mode is not selected (NO in S101), the first to fourth cartridges 6K, 6M, 6C, and 6Y are selected (S103), and image forming processing is performed (S104).
Thus, by selecting the fifth cartridge 6X when the toner saving mode is selected, it is possible to reduce toner consumption. In this example, the fifth cartridge 6X is set to the same color as the first cartridge 6K, but may be set to the same color as the second to fourth cartridges 6M, 6C, and 6Y.

FIG. 6 is a schematic configuration diagram regarding a modification of the present embodiment. The configurations denoted by the same reference numerals as those in FIG. 1 are the same as the configurations shown in FIG. In this example, the collected residual toner is reused in the toner saving mode. The inside of the waste toner box 50 is divided into a disposal section 50A and a reuse section 50B, and residual toner collected from the first to fourth cartridges 6K, 6M, 6C, and 6Y is discharged into the disposal section 50A. The reusable section 50B is set so that the residual toner collected from the fifth cartridge 6X is discharged. The reusable section 50B is provided with a toner transfer path between the fifth cartridge 6X and a toner bottle (not shown), and the residual toner stored in the recycle section 50B is removed by a toner transfer means (not shown). No. 5 cartridge 6X is transferred to the toner bottle.
Similarly to the example described with reference to FIG. 5, by selecting the fifth cartridge 6X when the toner saving mode is selected, the toner can be reused, and the toner consumption can be further reduced. .

FIG. 7 is an explanatory diagram relating to an image forming process when the user sets an image area where a plurality of cartridges of the same color form an image. In this example, the user sets an image quality emphasis area and a toner density emphasis area using the operation unit of the apparatus (FIG. 7A). The toner density emphasis area is an area where the toner consumption is reduced by setting the toner density low. For this reason, the developing conditions of the fifth cartridge 6X are set in advance so that the toner density becomes low. In this example, the fifth cartridge 6X forms an image with the same color as the first cartridge 6K. In the image quality emphasis region, the first to fourth cartridges 6K, 6M, 6C, and 6Y are set to perform normal image forming processing in order to form an image such as a pattern.
Next, image formation processing is performed with the first to fourth cartridges 6K, 6M, 6C, and 6Y in the set image quality emphasis area, and a fifth cartridge is used instead of the first cartridge 6K in the set toner density emphasis area. 6X is used to perform image forming processing with the second to fifth cartridges 6M, 6C, 6Y, and 6X (FIG. 7B). Then, the printed matter is output by superimposing the images formed in the image quality emphasis region and the toner density emphasis region (FIG. 7C).
Also in this case, it is possible to realize an image forming process in which the amount of toner consumption is suppressed without degrading the image quality in the area where the image quality is important according to the user's request.

FIG. 8 is an explanatory diagram regarding image forming processing when the user sets pages on which images are formed by a plurality of cartridges of the same color. In this example, the user sets an image quality priority page and a toner density priority page using the operation unit of the apparatus (FIG. 8A). The toner density priority page is an area in which the toner consumption is reduced by setting the toner density low. For this reason, the developing conditions of the fifth cartridge 6X are set in advance so that the toner density becomes low. In this example, the fifth cartridge 6X forms an image with the same color as the first cartridge 6K. In the image-oriented page, the first to fourth cartridges 6K, 6M, 6C, and 6Y are set to perform normal image forming processing in order to form an image such as a picture.
Next, image formation processing is performed with the first to fourth cartridges 6K, 6M, 6C, and 6Y on the set image quality priority page, and the fifth cartridge is used instead of the first cartridge 6K on the set toner density priority page. 6X is used to perform image forming processing with the second to fifth cartridges 6M, 6C, 6Y, and 6X (FIG. 8B). Then, the images formed on the image quality priority page and the toner density priority page are overlapped to output a printed matter (FIG. 8C).
Also in this case, it is possible to realize an image forming process in which the amount of toner consumption is suppressed without degrading the image quality of a page that places importance on image quality in response to a user request.

  In the example described above, one cartridge is added to the four color cartridges and a pair of the same color cartridges are provided. However, two or more cartridges are added to the four color cartridges and the same color is added. A plurality of pairs of cartridges can be provided.

  DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Paper feed roller, 3 ... Registration roller, 4 ... Paper feed tray, 5 ... Transfer belt, 6K, 6M, 6C, 6Y, 6X ... Cartridge, 7 ... secondary transfer driving roller, 8 ... transfer belt tension roller, 9K, 9M, 9C, 9Y, 9X ... photosensitive member, 10K, 10M, 10C, 10Y, 10X ... charger 11 ... Exposure unit, 12K, 12M, 12C, 12Y, 12X ... Developer, 13K, 13M, 13C, 13Y, 13X ... Cleaner blade, 14K, 14M, 14C, 14Y, 14X ... Laser light, 15K, 15M, 15C, 15Y, 15X ... primary transfer roller, 16 ... secondary transfer roller, 18 ... discharge roller, 19 ... double-sided roller, 20 ... fixing device, 21. Fixing La, 22 ... pressing roller, 30 ... document reading unit, 50 ... waste toner box.

JP 2009-055601 A JP 2009-037138 A

Claims (10)

  In an image forming apparatus that forms toner images corresponding to a plurality of different colors and superimposes the toner images to form a color image on a recording medium, an image processing unit that generates image data of a plurality of different colors, and A plurality of image forming means for forming a toner image corresponding to each color of the image data and partly forming a toner image of the same color; and the image forming for forming a toner image of the same color among the image forming means An image forming apparatus comprising setting processing means for setting different image forming conditions for each of the means.   The image forming apparatus according to claim 1, wherein the setting processing unit sets an image forming condition so that a toner density of a toner image formed by the image forming unit is different.   The image forming apparatus according to claim 2, wherein the image forming unit in which the toner density of the toner image is set low includes a unit that reuses the collected residual toner.   The image forming apparatus according to claim 1, further comprising a selection processing unit that selects at least one of the image forming units that form toner images of the same color and performs an image forming process.   The image processing means includes means for extracting a feature quantity that identifies an image area based on the image data, and means for generating image data corresponding to a plurality of image areas based on the extracted feature quantity. The image forming apparatus according to claim 4, wherein the selection processing unit causes the image forming unit that forms a toner image of the same color to perform an image forming process corresponding to each of the image regions.   The image forming apparatus according to claim 5, wherein the feature amount specifies an image region in which image quality is important and an image region in which image quality is not important.   5. The image processing unit according to claim 4, wherein the selection processing unit causes the image forming unit that forms a toner image of the same color to correspond to an image area in which the set image quality is important and an image area in which the image quality is not important. Image forming apparatus.   The image forming apparatus according to claim 7, wherein the image area in which image quality is important and the image area in which image quality is not important are set for each page on which image formation processing is performed.   In an image forming method of forming a toner image corresponding to a plurality of different colors and superimposing the toner images to form a color image on a recording medium, a plurality of image formations for forming a toner image of the same color under different image forming conditions An image forming method in which image forming processing is performed by another image forming unit corresponding to a plurality of specified image areas.   The image formation according to claim 9, wherein image formation processing is performed by an image forming unit having a high toner density on an image region in which image quality is important, and image forming processing is performed by an image forming unit having a low toner density in an image region in which image quality is not important. Method.

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