Image forming apparatus, image forming method, and computer readable medium

Abstract

The invention discloses an image forming apparatus, an image forming method, and a computer-readable medium, the image forming apparatus includes a plurality of image forming units that adhere a developer to a surface of an image holding body to form an image and transfer the image to a recording medium in one direction, the image forming apparatus includes an image forming unit that forms an image of a developer of one color on a surface of an image holder; an image forming apparatus includes a first image forming unit that forms an image of a developer of another color on a surface of a first image holding body, and another image forming unit that forms an image of the developer of another color on a surface of the other image holding body, the image forming apparatus including a contact member having a tip portion in contact with a transferred surface of the other image holding body, the developer of the other color is attached to the surface of the other image holding body to form a preset image, and an operation of passing the image of the surface between the transferred surface and the tip portion of the contact member is performed at a preset frequency.

Description

Technical Field

[0001] The present invention relates to an image forming device, an image forming method and a computer readable medium. Background Art

[0002] For example, a structure is disclosed in Japanese Patent Gazette No. 2019-78787, which includes a maintenance unit, which uses an image generating unit to form a maintenance image based on charged particles for image generation on an image retaining body, and rotates the image retaining body without performing a transfer action by a transfer unit, so that the maintenance image passes periodically or irregularly relative to a blocking component, and the maintenance image used in the maintenance unit has a plurality of band-shaped images extending continuously or discontinuously along a cross direction that crosses the rotation direction of the image retaining body, and the band-shaped image has a concave-convex pattern in which a plurality of convex portions are arranged at intervals relative to the rotation direction of the image retaining body, regardless of where the band-shaped image is in the cross direction of the image retaining body. Summary of the invention

[0003] Here, a case where a plurality of image forming units are provided in one direction to form an image by attaching a developer to the surface of an image retaining body and transferring the image to a recording medium can be considered. The image forming units include: an image forming unit that forms an image of a developer of one color; and another image forming unit that is located on the downstream side of the one image forming unit and forms an image of a developer of another color on the surface of the other image retaining body, and includes a contact member whose front end contacts the surface of the other image retaining body after the transfer. In this case, when the developer of one color accumulates and forms a lump at the front end of the contact member, the lump may fall on the recording medium, resulting in poor image quality.

[0004] An object of the present invention is to suppress the occurrence of poor image quality, compared with a situation in which, in another image forming unit located on the downstream side of an image forming unit that forms an image of a developer of one color and having another image retaining body that forms an image of a developer of another color, the developer of one color is not prevented from accumulating and forming a lump at the front end portion of a contact member that contacts the surface of the other image retaining body after transfer.

[0005] According to a first aspect of the present invention, an image forming device is provided, which has a plurality of image forming units along one direction for making a developer adhere to the surface of an image retaining body to form an image and transfer it to a recording medium. As the image forming units, there are one image forming unit and another image forming unit. The one image forming unit forms an image of a developer of one color on the surface of the one image retaining body, and the other image forming unit is located on the downstream side of the one image forming unit, forms an image of a developer of another color on the surface of the other image retaining body, and includes a contact component whose front end contacts the surface of the other image retaining body after transfer. In the image forming device, the developer of the other color is made to adhere to the surface of the other image retaining body to form a predetermined image, and the image of the surface is made to pass between the surface after transfer and the front end of the contact component at a predetermined frequency.

[0006] According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the other image forming unit is a plurality of other image forming units that form images of respective developers of YMCK colors as images of the developer of the other color.

[0007] According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the preset frequency is set for each of the plurality of the other image forming units.

[0008] According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, the preset frequency decreases in the plurality of another image forming units as progressing toward the downstream side.

[0009] According to a fifth aspect of the present invention, in the image forming apparatus according to the third aspect, the preset frequency is set based on information indicating a usage amount of a developer of one color.

[0010] According to the sixth aspect of the present invention, in the image forming device based on any one of the first to fifth aspects, the predetermined image includes a developer portion extending along the axial direction of the other image retaining body and a non-developer portion arranged between the developer portions separated from each other in a direction intersecting the axial direction.

[0011] According to a seventh aspect of the present invention, in the image forming apparatus according to the sixth aspect, the number of the developer portion decreases as proceeding toward the downstream side in a case where the another image forming unit is a plurality of image forming units.

[0012] According to an eighth aspect of the present invention, in the image forming apparatus according to any one of the first to seventh aspects, the one image forming unit does not form the preset image.

[0013] According to a ninth aspect of the present invention, there is provided a computer-readable medium storing a program for causing a computer controlling an image forming apparatus to execute processing, wherein the image forming apparatus has a plurality of image forming units along one direction for causing a developer to adhere to a surface of an image retaining body to form an image and transfer the image to a recording medium, wherein the image forming units include one image forming unit and another image forming unit, wherein the one image forming unit forms an image of a developer of one color on a surface of the one image retaining body, and the other image forming unit is located on the downstream side of the one image forming unit, forms an image of a developer of another color on a surface of the other image retaining body, and includes a contact component whose front end contacts the surface of the other image retaining body after transfer, wherein in the computer-readable medium, the processing includes: a process of acquiring the number of times an image of a developer of one color is formed by the one image forming unit; and when the acquired number of times satisfies a preset condition, causing the developer of the other color to adhere to the surface of the other image retaining body to form a preset image, and performing an action of causing the image on the surface to pass between the front end of the contact component.

[0014] According to the tenth aspect of the present invention, there is provided an image forming method, which is an image forming method of an image forming device, wherein the image forming device has a plurality of image forming units along a direction for making a developer adhere to the surface of an image retaining body to form an image and transfer it to a recording medium, and as the image forming units, it has an image forming unit and another image forming unit, the one image forming unit forms an image of a developer of one color on the surface of the one image retaining body, the other image forming unit is located on the downstream side of the one image forming unit, forms an image of a developer of another color on the surface of the other image retaining body, and includes a contact component whose front end contacts the surface of the other image retaining body after transfer, in the image forming method, the developer of the other color is made to adhere to the surface of the other image retaining body to form a predetermined image, and the image of the surface is caused to pass between the surface after transfer and the front end of the contact component at a predetermined frequency.

[0015] (Effect)

[0016] According to the first aspect, the occurrence of poor image quality can be suppressed compared to a situation in which, in another image forming unit located on the downstream side of an image forming unit that forms an image of a developer of one color and having another image retaining body that forms an image of a developer of another color, the developer of one color is not prevented from accumulating and forming a block at the front end portion of a contact member that contacts the surface of the other image retaining body after transfer.

[0017] According to the second aspect, the other image forming units are a plurality of other image forming units that form images of the respective developers of YMCK colors as images of the developer of another color, and the occurrence of poor image quality can be suppressed compared to a case without such a configuration.

[0018] According to the third aspect, the preset frequency is set for each of the plurality of other image forming units, and the occurrence of poor image quality can be suppressed compared to a case where this configuration is not provided.

[0019] According to the fourth aspect, the preset frequency decreases in the plurality of other image forming units as the frequency progresses toward the downstream side, and consumption of the other color developer can be suppressed compared to a case where this configuration is not provided.

[0020] According to the fifth aspect, the preset frequency is set based on the information indicating the usage amount of the developer of one color, and the occurrence of poor image quality can be suppressed compared to a case where this configuration is not provided.

[0021] According to the sixth aspect, the predetermined image includes a developer portion extending along the axial direction of another image retaining body and a non-developer portion arranged between the developer portions separated from each other in a direction intersecting the axial direction, which can suppress the occurrence of poor image quality compared to a case without this structure.

[0022] According to the seventh aspect, when the other image forming unit is a plurality of image forming units, the amount of developer portion decreases toward the downstream side, and consumption of the other color developer can be suppressed compared to a case without this configuration.

[0023] According to the eighth aspect, one image forming unit does not form a preset image, and thus the consumption of developer of one color can be suppressed compared to a case where this configuration is not provided.

[0024] According to the ninth aspect, the occurrence of poor image quality can be suppressed compared to a situation in which, in another image forming unit located on the downstream side of an image forming unit that forms an image of a developer of one color and having another image retaining body that forms an image of a developer of another color, the developer of one color is not prevented from accumulating and forming a block at the front end portion of a contact member that contacts the surface of the other image retaining body after transfer.

[0025] According to the tenth aspect, the occurrence of poor image quality can be suppressed compared to a situation in which, in another image forming unit located on the downstream side of an image forming unit that forms an image of a developer of one color and having another image retaining body that forms an image of a developer of another color, the developer of one color is not prevented from accumulating and forming a block at the front end portion of a contact member that contacts the surface of the other image retaining body after transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A diagram for explaining an image forming apparatus;

[0027] Figure 2 A diagram for explaining a developer of an image forming apparatus;

[0028] Figure 3 A diagram illustrating the periphery of a photosensitive drum of an image forming apparatus;

[0029] Figure 4 is a diagram showing a configuration example of hardware of a control unit of an image forming apparatus;

[0030] Figure 5 is a block diagram illustrating the functional structure of the control unit;

[0031] Figure 6 This is a diagram showing an example of an image used in the disintegration action;

[0032] Figure 7 This is a diagram for explaining the disintegration action performed by the image;

[0033] Figure 8 is a flowchart showing an example of a processing procedure for a collapse action;

[0034] Fig. 9 : is a table showing application examples of the collapsing operation in each image forming unit, (a) shows the frequency of performing the collapsing operation, and (b) shows the number of band-shaped portions of the image. DETAILED DESCRIPTION

[0035] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0036] Figure 1 It is a diagram for explaining the image forming apparatus 1 .

[0037] The image forming apparatus 1 according to the present embodiment includes a paper feeding unit 1A, a printing unit 1B, and a paper discharge unit 1C.

[0038] The paper feeding unit 1A includes first to fourth paper storage sections 11 to 14 for storing paper P as an example of recording media.

[0039] The paper feeding unit 1A is provided with delivery rollers 15 to 18 , which are respectively provided corresponding to the first to fourth paper storage sections 11 to 14 , and deliver the paper P stored in each paper storage section to a conveying path connected to the printing unit 1B.

[0040] The printing unit 1B includes an image forming section 20 that forms an image on a sheet of paper P. In addition, the printing unit 1B is provided with a control section 21 that controls each section of the image forming apparatus 1 .

[0041] The printing unit 1B also includes an image processing unit 22 . The image processing unit 22 performs image processing on image data sent from the image reading device 4 or a personal computer (PC) 5 .

[0042] The printing unit 1B is provided with a UI (User Interface) 23 which is composed of a touch panel or the like and which notifies information to the user and receives input of information from the user.

[0043] In the image forming section 20 as an example of the image forming unit, six image forming units 30T, 30P, 30Y, 30M, 30C, and 30K (hereinafter, sometimes simply referred to as “image forming units 30 ”) are arranged side by side at regular intervals.

[0044] Each image forming unit 30 includes: a photosensitive drum 31 that forms an electrostatic latent image while rotating in the direction of arrow A, a charging roller 32 that charges the surface of the photosensitive drum 31, a developer 33 that develops the electrostatic latent image formed on the photosensitive drum 31, and a drum cleaner 34 that removes colorant and the like on the surface of the photosensitive drum 31.

[0045] The image forming section 20 is provided with a laser exposure device 26 for exposing the photosensitive drum 31 of each image forming unit 30 to light using laser light.

[0046] The exposure of the photosensitive drum 31 by the laser exposure device 26 is not limited to the use of lasers. For example, a light source such as an LED (Light Emitting Diode) may be provided in each image forming unit 30, and the photosensitive drum 31 may be exposed using light emitted from the light source.

[0047] Each image forming unit 30 has the same configuration except for the toner stored in the developing device 33. The image forming units 30Y, 30M, 30C, and 30K form toner images of yellow (Y), magenta (M), cyan (C), and black (K), respectively.

[0048] The image forming units 30T and 30P form toner images using toner corresponding to corporate colors, foaming toner for Braille, fluorescent toner, gloss-enhancing toner, etc. In other words, the image forming units 30T and 30P form toner images using toner of special colors.

[0049] Here, the image forming units 30T and 30P are an example of an image forming unit that forms an image of a developer of one color on the surface of an image holding body, and the image forming units 30Y, 30M, 30C, and 30K are an example of another image forming unit that is located on the downstream side of the image forming unit and forms an image of a developer of another color on the surface of another image holding body. That is, the photosensitive drum 31 of the image forming units 30T and 30P is an example of an image holding body, and the developer of one color is the developer of the image forming units 30T and 30P. In addition, the photosensitive drum 31 of the image forming units 30Y, 30M, 30C, and 30K is an example of another image holding body, and the developer of another color is the developer of the image forming units 30Y, 30M, 30C, and 30K.

[0050] The image forming section 20 is provided with an intermediate transfer belt 41 that transfers the toner images of the respective colors formed on the photosensitive drums 31 of the respective image forming units 30 .

[0051] The image forming section 20 is provided with a primary transfer roller 42 that transfers the toner images of the respective colors of the image forming units 30 onto the intermediate transfer belt 41 at the primary transfer section T1 .

[0052] The image forming section 20 is provided with a secondary transfer roller 40 that transfers the toner image transferred onto the intermediate transfer belt 41 onto the paper P at the secondary transfer section T2 .

[0053] Furthermore, the image forming section 20 is provided with a belt cleaner 45 for removing toner and the like on the surface of the intermediate transfer belt 41 , and a fixing device 80 for fixing the secondarily transferred image on the paper P.

[0054] The image forming section 20 performs an image forming operation based on a control signal from the control section 21 .

[0055] Specifically, in the image forming unit 20 , first, image processing is performed by the image processing unit 22 on image data input from the image reading device 4 or the PC 5 , and the image data after the image processing is supplied to the laser exposure device 26 .

[0056] For example, in the image forming unit 30M for magenta (M), after the surface of the photosensitive drum 31 is charged by the charging roller 32 , the laser exposure device 26 irradiates the photosensitive drum 31 with laser light modulated by image data obtained from the image processing unit 22 .

[0057] Thus, an electrostatic latent image is formed on the photosensitive drum 31 .

[0058] The formed electrostatic latent image is developed by the developing device 33 , and a magenta toner image is formed on the photosensitive drum 31 .

[0059] Similarly, yellow, cyan, and black toner images are formed in the image forming units 30Y, 30C, and 30K, and special color toner images are formed in the image forming units 30T and 30P.

[0060] The toner images of each color formed in each image forming unit 30 are electrostatically transferred to the image forming units 30 in sequence by the primary transfer roller 42. Figure 1 A toner image superimposed on the intermediate transfer belt 41 is formed on the intermediate transfer belt 41 rotating in the direction of arrow C.

[0061] The superimposed toner images formed on the intermediate transfer belt 41 are conveyed to the secondary transfer portion T2 constituted by the secondary transfer roller 40 and the backup roller 49 as the intermediate transfer belt 41 moves.

[0062] On the other hand, the paper P is taken out from the first paper storage unit 11 by, for example, the delivery roller 15 , and then transported to the position of the registration roller 74 via the transport path.

[0063] When the superimposed toner images are conveyed to the secondary transfer portion T2 , the paper P is supplied from the registration roller 74 to the secondary transfer portion T2 in timing with the conveyance.

[0064] Then, in the secondary transfer portion T2 , the superimposed toner images are electrostatically transferred onto the paper P at once by the action of a transfer electric field formed between the secondary transfer roller 40 and the backup roller 49 .

[0065] Thereafter, the paper P to which the superimposed toner images are electrostatically transferred is conveyed to the fixing device 80 .

[0066] In the fixing device 80 , the paper P on which the unfixed toner image is formed is pressed and heated, and a fixing process of the toner image on the paper P is performed.

[0067] Then, the paper P subjected to the fixing process passes through the curl correcting section 81 provided in the paper discharge unit 1C, and is then conveyed to a paper loading section (not shown).

[0068] Figure 2 This is a diagram for explaining the developing device 33 of the image forming apparatus 1, and is Figure 1 The schematic front view of the developing device 33 is seen from the same direction as shown.

[0069] like Figure 2 As shown, the developing device 33 includes a storage portion 331 for storing a developer (not shown) therein. The storage portion 331 is composed of a resin storage frame 332. The developer is composed of a magnetic carrier and a colored toner, and is a so-called two-component developer.

[0070] The housing frame 332 of the developing device 33 is arranged along the direction from the image forming apparatus 1 (see Figure 1 )'s front side toward the rear side, that is, Figure 2 The structure is configured to extend in a direction perpendicular to the paper surface, and has a near-front part (not shown) on the front side and a back-side part (not shown) on the rear side.

[0071] In the storage frame 332, the photosensitive drum 31 (see Figure 1 ) is provided at a position opposite to the photosensitive drum 31. A developing roller 334 is provided at the opening 333 to attach the developer to the surface of the photosensitive drum 31. The developing roller 334 holds the developer supplied to the photosensitive drum 31. The position where the developer of the developing roller 334 is supplied to the photosensitive drum 31 is sometimes referred to as a developing position.

[0072] The developing roller 334 is formed in a cylindrical shape, and is arranged so as to extend in a direction from the front side to the rear side of the image forming apparatus 1. In other words, the developing roller 334 is arranged so as to extend along the longitudinal direction of the developing device 33.

[0073] The developing roller 334 is provided with a developing sleeve 334G which is composed of a cylindrical body and is driven to rotate, and a magnetic roller 334H which is arranged on the inner side of the developing sleeve 334G.

[0074] The developing sleeve 334G is made of metal such as SUS, etc. The developing sleeve 334G rotates in the direction of arrow D in the figure.

[0075] In the present embodiment, at the primary transfer portion T1 (see FIG. 1 ) between the developing roller 334 and the photosensitive drum 31, Figure 1 ) in the image processing apparatus, the developing sleeve 334G and the photosensitive drum 31 rotate so that the developing sleeve 334G and the photosensitive drum 31 move in the same direction.

[0076] The developing device 33 is provided with a layer regulating member 335 for regulating the layer thickness of the developer held by the developing roller 334 .

[0077] In addition, if Figure 2 As shown, the developer 33 is provided with a first conveying portion 336, a second conveying portion 337, and a third conveying portion 338 for conveying the developer. Hereinafter, the first conveying portion 336, the second conveying portion 337, and the third conveying portion 338 may be referred to as conveying portions 336 to 338.

[0078] The conveying sections 336 to 338 are provided at a position close to the photosensitive drum 31 (see FIG. Figure 1 ) is on the side opposite to the setting side.

[0079] The conveying parts 336 to 338 are respectively provided with rotating members 51, 52, 53 extending along the rotating shaft of the developing sleeve 334G which is driven to rotate, and rotate around the rotating members 51 to 53. That is, the conveying parts 336 to 338 are arranged to be close to the photosensitive drum 31 (see Figure 1 ) are roughly parallel.

[0080] Next, the rotation speeds of the developing roller 334 and the rotating members 51 to 53 of each developer 33 are described according to the case where a special color toner image is not formed and the case where a special color toner image is formed by the image forming unit 30. The rotation speed of the rotating members 51 to 53 is sometimes referred to as the speed of the conveying sections 336 to 338.

[0081] The following is a description of the implementation method.

[0082] Figure 3 1 is a diagram for explaining the periphery of the photosensitive drum 31 of the image forming apparatus 1. Figure 3 The photosensitive drum 31 shown is a component that each of the image forming units 30 has.

[0083] Around the photosensitive drum 31, the above-mentioned charging roller 32, developing roller 334, primary transfer roller 42, and drum cleaner 34 are arranged along the direction of arrow A. The drum cleaner 34 will be described in detail below.

[0084] The drum cleaner 34 cleans the surface 31a of the photosensitive drum 31 on the downstream side of the primary transfer portion T1 as indicated by the arrow A, and removes the toner and the like remaining on the surface 31a after the transfer. The drum cleaner 34 also collects the removed matter.

[0085] The drum cleaner 34 includes a main body 61 , a scraper 62 , a partition member 63 , a conveying member 64 , and a contact member 65 .

[0086] The main body 61 holds components such as the scraper 62 .

[0087] The scraper 62 is mounted on the main body 61 so as to be inclined in the direction opposite to the direction of arrow A with respect to the surface 31 a of the photosensitive drum 31 , and cleans the surface 31 a with the front end in contact with the surface 31 a .

[0088] The partition member 63 is located between the main body 61 and the surface 31 a of the photosensitive drum 31 , and forms a space S for storing the removed matter removed by the scraper 62 .

[0089] The transport member 64 is disposed in the space S and extends along the rotation axis of the photosensitive drum 31. The transport member 64 transports the removable objects by rotating, and thereby the removable objects are recovered.

[0090] The contact member 65 is arranged to cover the gap between the body 61 and the partition member 63 , forming a space S together with the partition member 63 .

[0091] More specifically, the contact member 65 is disposed from the main body 61 toward the surface 31 a of the photosensitive drum 31 .

[0092] To further describe, one end of the contact member 65 is attached to the main body 61 in a manner inclined in the direction of arrow A, and the other end, namely the front end 65a, contacts the surface 31a, and a part of it itself is deformed, for example, to follow the surface 31a.

[0093] More specifically, the toner and the like that have passed between the front end portion 65a of the contact member 65 and the surface 31a of the photosensitive drum 31 are distinguished from the toner and the like that have not passed between the front end portion 65a of the contact member 65 and the surface 31a of the photosensitive drum 31. That is, for each image forming unit 30, the degree of deformation based on the material or thickness of the contact member 65 and the gap between the front end portion 65a and the surface 31a are set according to conditions such as the amount of toner supplied from the developing roller 334 to the photosensitive drum 31.

[0094] Thus, the toner and the like on the photosensitive drum 31 remaining on the surface 31a after being conveyed passes between the surface 31a and the front end 65a of the contact member 65 and moves to the position of the scraper 62. Meanwhile, the removal objects stored in the space S are restricted from moving outside the main body 61.

[0095] The contact member 65 of the present embodiment may be made of, for example, a soft resin film.

[0096] Here, in the present embodiment, the arrow C (see FIG. 1 ) along the intermediate transfer belt 41 Figure 1 ) direction, that is, among the image forming units provided in a plurality of directions, the image forming units 30T and 30P using special color toner are arranged on the upstream side (refer to Figure 1 ). In addition, image forming units 30Y, 30M, 30C, and 30K using any one of YMCK colors are arranged on the downstream side of the image forming units 30T and 30P (see Figure 1 ) This corresponds to the requirement that the image of the toner of a special color is preferably formed on the uppermost stream when considering the background when a transparent recording medium such as a cell image is viewed from the back side.

[0097] In addition, the particle size of the special color toner is larger than that of the YMCK color toner. Therefore, in the image forming units 30T and 30P, the toner with a large particle size can pass between the surface 31a of the photosensitive drum 31 and the front end 65a of the contact member 65 and be stored in the space S. On the other hand, in the image forming units 30Y, 30M, 30C, and 30K, the toner with a small particle size can pass between the surface 31a and the front end 65a and be stored in the space S, and the toner with a large particle size cannot pass between the surface 31a and the front end 65a.

[0098] Therefore, among the image forming units 30Y, 30M, 30C, and 30K, when the special color toner of the image forming units 30T and 30P adheres to the surface 31a of the photosensitive drum 31 from the upstream side via the intermediate transfer belt 41, it may not pass between the surface 31a and the front end portion 65a and accumulate on the front end portion 65a.

[0099] The YMCK color toners are approximately spherical in shape, but the special color toners are different in shape from the YMCK color toners, so they tend to become larger and form lumps after being deposited on the front end portion 65a. When they become large lumps, the risk of falling from the front end portion 65a due to their own weight increases, and if they fall on the intermediate transfer belt 41, for example, it causes poor image quality.

[0100] Therefore, in the present embodiment, in order to prevent the special color toner accumulated on the contact member 65 from forming a lump, a control is adopted to perform a disintegration operation for disintegrating the special color toner accumulated on the contact member 65. In addition, the disintegration operation is an operation for removing the special color toner from the front end portion 65a, and can also be performed in a state where the special color toner is attached to the contact member 65, that is, in a state before the special color toner is accumulated.

[0101] The collapsing operation is described in detail below. The collapsing operation is an example of an operation for passing the image on the surface between the transferred surface and the front end of the contact member.

[0102] Figure 4 1 is a diagram showing a configuration example of hardware of the control unit 21 of the image forming apparatus 1. The control unit 21 provided in the image forming apparatus 1 is realized by a computer.

[0103] The control unit 21 includes a calculation processing unit 21 a that executes digital calculation processing according to a program and a secondary storage unit 21 g that stores information.

[0104] The secondary storage unit 21g is realized by an existing information storage device such as a HDD (Hard Disk Drive), a semiconductor memory, or a magnetic tape.

[0105] The calculation processing unit 21 a is provided with a CPU 21 b as an example of a processor.

[0106] The calculation processing unit 21 a is provided with a RAM 21 c used as a working memory or the like of the CPU 21 b , and a ROM 21 d storing programs or the like executed by the CPU 21 b .

[0107] The arithmetic processing unit 21a is provided with a nonvolatile memory 21e which is rewritable and can retain data even when power supply is interrupted, and an interface unit 21f which controls various units such as a communication unit connected to the arithmetic processing unit 21a.

[0108] The nonvolatile memory 21e is composed of, for example, a battery-backed SRAM or flash memory, etc. The secondary storage unit 21g stores not only files, but also programs executed by the arithmetic processing unit 21a.

[0109] In the present embodiment, the arithmetic processing unit 21 a reads the program stored in the ROM 21 d and the secondary storage unit 21 g to execute each process.

[0110] The program executed by the CPU 21b may be provided to the image forming apparatus 1 in a state in which it is stored in a computer-readable recording medium such as a magnetic recording medium (a magnetic tape, a magnetic disk, etc.), an optical recording medium (an optical disk, etc.), an optical magnetic recording medium, or a semiconductor memory. In addition, the program executed by the CPU 21b may be provided to the image forming apparatus 1 using a communication unit such as the Internet.

[0111] In this specification, the processor refers to a processor in a broad sense, including general-purpose processors (such as CPU: Central Processing Unit, central processing unit, etc.), special-purpose processors (such as GPU: Graphics Processing Unit, graphics processor, ASIC: Application Specific Integrated Circuit, application-specific integrated circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0112] In addition, the actions of the processors are not performed by only one processor, but may be performed by cooperation of multiple processors located in physically separate locations. In addition, the order of the actions of the processors is not limited to the order described in this embodiment, and may also be changed.

[0113] Figure 5 This is a block diagram for explaining the functional configuration of the control unit 21 .

[0114] exist Figure 5In the example shown, the control unit 21 includes a frequency information acquisition unit 91, a collapse action execution judgment unit 92, an execution content determination unit 93, and a collapse action control unit 94. The frequency information acquisition unit 91 and the like are controlled by the CPU 21b (see Figure 4 )accomplish.

[0115] The number information acquisition unit 91 acquires number information indicating the number of times the image forming units 30T and 30P have performed printing using a special color toner. The number information is the number of times printing has been performed after the collapse operation has been performed. The number information acquisition unit 91 is an example of a function for acquiring the number of times an image of a developer of a single color has been formed by a single image forming unit.

[0116] The collapse operation execution determination unit 92 determines whether the collapse operation is executed in the image forming units 30Y, 30M, 30C, and 30K based on the frequency information acquired by the frequency information acquisition unit 91 .

[0117] This disintegration action is performed at a preset frequency. Therefore, it is determined whether the execution period of the disintegration action has arrived based on whether the acquired frequency information has reached a value corresponding to the preset frequency.

[0118] To further explain, in addition to the case where the collapse operation is performed simultaneously in the image forming units 30Y, 30M, 30C, and 30K, it is also possible to consider the case where the image forming units 30Y, 30M, 30C, and 30K are individually executed. Therefore, in the former case, it is sufficient to judge any one of the image forming units 30Y, 30M, 30C, and 30K, for example, the image forming unit 30Y. In addition, in the latter case, the image forming units 30Y, 30M, 30C, and 30K are judged separately.

[0119] When the collapse action execution determination unit 92 determines that the collapse action is to be executed, the execution content determination unit 93 determines the content to be executed as the collapse action. The content may be the same for the image forming units 30Y, 30M, 30C, and 30K, or may be different for each image forming unit 30Y, 30M, 30C, and 30K.

[0120] The collapsing operation control unit 94 controls the collapsing operation so that the content determined by the execution content determination unit 93 is achieved. This control is performed on the surface 31a (refer to Figure 3 ) forms a toner image in accordance with the determined content, without the primary transfer section T1 (refer to Figure 3 ) is transferred to the intermediate transfer belt 41 (refer to Figure 3 ), but by contacting the front end portion 65a of the contact member 65 (refer to Figure 3The collapse action control unit 94 is an example of a function that performs an action.

[0121] Figure 6 66 is a diagram showing an example of an image 66 used for the collapse action. The image 66 is based on the execution content determination unit 93 (see Figure 5 ) determines the toner image of the content.

[0122] like Figure 6 As shown in the image 66, the band-shaped portion 67a of the toner image extending in the width direction W of the photosensitive drum 31 is arranged along the direction of arrow A. More specifically, Figure 6 The image 66 shown includes a plurality of unit regions 67 including a strip-shaped portion 67 a .

[0123] The unit area 67 includes a strip-shaped portion 67 a and a blank portion 67 b located between adjacent strip-shaped portions 67 a .

[0124] The length of the strip-shaped portion 67a of the unit area 67 in the direction of arrow A is, for example, 2 mm, and the interval between the strip-shaped portions 67a is, for example, 2 mm. That is, in this case, the length of the blank portion 67b in the direction of arrow A is 2 mm.

[0125] Here, the image 66 is an example of a preset image. The width direction W of the photosensitive drum 31 is an example of the axial direction of another image holding body, and the arrow A direction is an example of a direction intersecting the axial direction. In addition, the belt-shaped portion 67a is an example of a developer portion, and the blank portion 67b is an example of a non-developer portion.

[0126] When showing an example of the strip-shaped portion 67 a , for example, the density is 80%, the length in the width direction W is 300 mm in total width, and the length in the direction of arrow A is 2 mm.

[0127] In addition, the image 66 may be configured such that, for example, 30 unit areas 67 are arranged in the direction of arrow A.

[0128] Such concentration, length in the width direction W, length in the direction of arrow A, and number of unit areas 67 are examples, and other values ​​may be used. In addition, it is also conceivable to set different values ​​for each image forming unit 30Y, 30M, 30C, 30K.

[0129] Figure 7 This is a diagram for explaining the collapse operation performed by the image 66 .

[0130] like Figure 7As shown, when an image 66 is formed on the surface 31a of the photosensitive drum 31, the transfer potential is controlled so that the image 66 on the surface 31a is not transferred in the primary transfer section T1. Thus, the image 66 on the surface 31a remains on the surface 31a even if it passes through the primary transfer section T1 and passes between the front end portion 65a of the contact member 65.

[0131] To further explain, since the image 66 of the surface 31a passes between the front end 65a, the contact member 65 in contact with the concave-convex repeated shape of the image 66 vibrates. More specifically, when the strip-shaped portion 67a of the image 66 passes between it and the front end 65a, the space between the surface 31a and the front end 65a expands, and when the strip-shaped portion 67a passes, the front end 65a intends to return to its original position. This movement of the front end 65a also occurs when the next strip-shaped portion 67a passes, so the front end 65a moves the number of strip-shaped portions 67a. This movement also involves another part of the front end 65a of the contact member 65.

[0132] Therefore, by the above-mentioned action, the contact member 65 vibrates, and the toner of the specific color on the contact member 65 is removed.

[0133] Furthermore, in order to vibrate the entire width direction of the contact member 65 , the image 66 is formed over the entire width.

[0134] The vibration of the contact member 65 causes the special color toner on the contact member 65 to leave the contact member 65. The vibration increases the space between the surface 31a and the contact member 65, so that the special color toner leaving the contact member 65 and reaching the surface 31a is easily introduced into the space S.

[0135] Furthermore, the image 66 on the surface 31 a is removed by the scraper 62 , stored in the space S, and recovered by the transport member 64 together with the toner of the specific color.

[0136] Figure 8 This is a flowchart showing an example of a processing procedure for the collapse action.

[0137] exist Figure 8 In the example shown, when the frequency information acquisition unit 91 (refer to Figure 5 ) When the number of times information is obtained (step S101), the collapse action execution determination unit 92 (refer to Figure 5 ) Determine whether the acquired number of times information meets the pre-set execution conditions (step S102).

[0138] The execution condition mentioned here is a condition for judging whether it is time to perform the disintegration action according to the number of times based on the acquired frequency information, for example, it can be considered to use the information of the preset frequency described later. For example, in the case where the preset frequency is "once every 200 times", it is a condition based on whether the number of times information has reached 200 times.

[0139] To further explain, the execution conditions mentioned here may be changed according to the type of special color colorant possessed by the image forming units 30T, 30P, such as white, gold, silver, etc. In addition, it is also possible to consider a situation where the execution conditions do not change and are set to the same regardless of the type of special color colorant possessed by the image forming units 30T, 30P.

[0140] In addition, the execution condition mentioned here may be changed according to the toner usage of the special color, in addition to being the same regardless of the toner usage of the special color in the image forming units 30T and 30P. For example, the control of changing the frequency is performed using information indicating the image density, which is the toner amount per unit area calculated for each print job. That is, the frequency is increased when the image density is high, and the frequency is decreased when the image density is low.

[0141] The information indicating the image density of the special color mentioned here can be obtained by the frequency information acquisition unit 91 of the control unit 21 (see Figure 5 ) and reflected in the judgment of the execution condition (refer to Figure 8 The information indicating the image density of a specific color is an example of information indicating the usage amount of a developer of one color.

[0142] In the present embodiment, when a plurality of image forming units including special color toners such as the image forming units 30T and 30P are provided, a total value of the usage amounts of the special color toners may be calculated and the execution condition may be changed according to the total value.

[0143] When the acquired frequency information satisfies the preset execution condition ("Yes" in step S102), the execution content determination unit 93 (refer to Figure 5 ) determines the execution content of the collapse action (step S103).

[0144] In addition, when the acquired number of times information does not satisfy the preset execution condition ("No" in step S102), the process returns to step S101.

[0145] As the execution content of the collapse action mentioned here, the strip-shaped portion 67a in the image 66 (see Figure 6 ) as an example.

[0146] The execution content may be different for each of the image forming units 30Y, 30M, 30C, and 30K, or the same content may be the same for each of the image forming units 30Y, 30M, 30C, and 30K.

[0147] Then, the collapse operation control unit 94 (see Figure 5 ) according to the determined execution content, the control of the disintegration action is performed (step S104). In this way, the disintegration action can be implemented regularly.

[0148] This control can be considered to insert the image 66 (see Figure 6 ). That is, as the timing for executing the collapsing operation, for example, in addition to the case where the image 66 is formed between the printed image and the next printed image, the case where the image 66 is formed after the final image is formed can also be considered.

[0149] Fig. 9 1 is a table showing application examples of the collapse operation in each image forming unit 30, (a) showing the frequency of the collapse operation, and (b) showing the number of strip-shaped portions 67a of the image 66. The number of strip-shaped portions 67a mentioned here may also be referred to as the number of unit areas 67 (see Figure 6 ).

[0150] Fig. 9 The frequency shown in (a) is an example of a preset frequency, and the number of the belt-shaped portions 67a shown in (b) is an example of the number of developer portions.

[0151] Fig. 9 The frequency shown in (a) of FIG. 1 indicates that when printing is performed on paper P using a special color toner in the image forming units 30T and 30P, the image forming units 30Y, 30M, 30C, and 30K perform a disintegration operation every several sheets. In this case, the paper P (refer to Figure 1 ) size, for example, A4 size. In the case of other sizes, you can consider converting it to A4 size.

[0152] exist Fig. 9 In the first example of the frequency shown in (a), the image forming units 30Y, 30M, 30C, and 30K all perform the collapsing action at a frequency of "once every 200 sheets". That is, the image forming units 30Y, 30M, 30C, and 30K perform the collapsing action at the same frequency. In this case, "200 sheets" corresponds to a value corresponding to a preset frequency.

[0153] In the second example of frequency, the amount of toner of a special color decreases as it goes downstream, and the disintegration operation is performed at a different frequency than in the first example. That is, the frequency of the image forming unit 30Y is "once every 200 sheets", the frequency of the image forming unit 30M is "once every 300 sheets", the frequency of the image forming unit 30C is "once every 400 sheets", and the frequency of the image forming unit 30K is "once every 500 sheets". In this way, in the second example of frequency, the frequency is set to decrease as it goes downstream for each of the image forming units 30Y, 30M, 30C, and 30K.

[0154] More specifically, the image forming unit 30Y close to the image forming units 30T and 30P has the highest frequency, and the image forming unit 30K far from the image forming units 30T and 30P has the lowest frequency. The frequency is set according to the distance relative to the image forming units 30T and 30P. In other words, the frequency is increased in the image forming unit 30Y close to the image forming units 30T and 30P and to which the toner of the special color reaches the largest amount. In addition, the frequency is reduced in the image forming unit 30K far from the image forming units 30T and 30P and to which the toner of the special color reaches the smallest amount.

[0155] Thus, the frequency varies with the intermediate transfer belt 41 (refer to Figure 1 ) is pushed down toward the downstream side in the direction of arrow C. When the frequency is high, the toner consumption increases, and when the frequency is low, the toner consumption is suppressed. Therefore, in the second example, compared with the first example, the toner consumption of YMCK colors is suppressed, and the toner accumulation at the front end portion 65a (refer to Figure 6 )'s special color toner turns into large clumps.

[0156] In the second example, for example, the control of the other image forming units 30M, 30C, and 30K when only the image forming unit 30Y performs the collapsing operation is described. In this case, the image 66 described above is formed in the image forming unit 30Y, while the same image as the image 66 formed in the image forming unit 30Y is not formed in the other image forming units 30M, 30C, and 30K. However, in order to prevent the scraper 62 (see Figure 3 ), it is conceivable to control the formation of images whose number is less than the number of strip-shaped portions 67a (for example, 1) of the image 66 of the image forming unit 30Y.

[0157] Fig. 9 The number of the strip-shaped portions 67a shown in (b) is the number of the strip-shaped portions 67a included in the image 66 (see Figure 6 The larger the number of the contact parts, the greater the tip 65a (refer to Figure 6 )The longer the vibration time is, the more reliably the toner of a specific color is removed from the front end portion 65a.

[0158] exist Fig. 9 In the first example shown in (b), each of the image forming units 30Y, 30M, 30C, and 30K performs the collapsing operation on the image 66 having “30” strip-shaped portions 67 a.

[0159] On the other hand, in the second example, there are “30” belt-shaped portions 67 a in the image forming unit 30Y, “25” belt-shaped portions 67 a in the image forming unit 30M, “20” belt-shaped portions 67 a in the image forming unit 30C, and “15” belt-shaped portions 67 a in the image forming unit 30K.

[0160] Thus, the number of the belt-shaped portions 67a is set to decrease as the intermediate transfer belt 41 moves toward the downstream side in the direction of arrow C. Therefore, in the second example, compared with the first example, the consumption of the toner of the YMCK colors is suppressed and the accumulation of the toner on the front end portion 65a of the contact member 65 (see Figure 6 )'s special color toner turns into large clumps.

[0161] In addition, Fig. 9 In the example shown, the image forming units 30T and 30P do not perform the collapsing operation, but it is conceivable that the image forming units 30T and 30P also perform the collapsing operation.

[0162] In the present embodiment, the image forming units 30Y, 30M, 30C, and 30K for forming images of YMCK colors and the image forming units 30T and 30P for forming images of special colors are provided, but the present invention is not limited thereto. For example, a configuration may be considered in which only a part of the image forming units 30Y, 30M, 30C, and 30K for forming images of YMCK colors, such as the image forming unit 30K, is provided. In addition, a configuration may be considered in which only one of the image forming units 30T and 30P is provided.

[0163] <Note> (((1)))

[0165] An image forming device includes a plurality of image forming units along one direction for forming an image by attaching a developer to the surface of an image holding body and transferring the image to a recording medium. The image forming units include one image forming unit and another image forming unit. The one image forming unit forms an image of a developer of one color on the surface of the one image holding body. The other image forming unit is located on the downstream side of the one image forming unit and forms an image of a developer of another color on the surface of the other image holding body. The other image forming unit includes a contact member whose front end portion contacts the surface of the other image holding body after the transfer.

[0166] In the image forming device, the developer of the other color is attached to the surface of the other image retaining body to form a predetermined image, and the image on the surface is passed between the transferred surface and the front end of the contact member at a predetermined frequency. (((2)))

[0168] The image forming apparatus according to (((1))), wherein:

[0169] The other image forming units are a plurality of other image forming units that form images of the developers of YMCK colors as images of the developer of the other color. (((3)))

[0171] An image forming apparatus according to (((2))), wherein:

[0172] The preset frequency is set for each of the plurality of other image forming units. (((4)))

[0174] The image forming apparatus according to (((3))), wherein:

[0175] The preset frequency decreases in the plurality of another image forming units as progressing toward the downstream side. (((5)))

[0177] The image forming apparatus according to (((3))), wherein:

[0178] The preset frequency is set based on information indicating the usage amount of developer of one color. (((6)))

[0180] The image forming apparatus according to any one of (((1))) to (((5))), wherein:

[0181] The predetermined image includes a developer portion extending in the axial direction of the other image holding member and a non-developer portion provided between the developer portions separated from each other in a direction intersecting the axial direction. (((7)))

[0183] An image forming apparatus according to (((6))), wherein:

[0184] The number of the developer portion decreases as proceeding toward the downstream side in a case where the another image forming unit is a plurality of image forming units. (((8)))

[0186] The image forming apparatus according to any one of (((1))) to (((7))), wherein:

[0187] The one image forming unit does not form the preset image. (((9)))

[0189] A program that causes a processor controlling an image forming device to implement the following steps:

[0190] a step of acquiring the number of times an image of a developer of one color is formed by the one image forming unit; and

[0191] When the number of acquisitions satisfies a preset condition, the developer of the other color is attached to the surface of the other image holding body to form a preset image, and a process is performed to make the image on the surface pass between the front end portion of the contact member,

[0192] The image forming device includes a plurality of image forming units along one direction for making a developer adhere to the surface of an image retaining body to form an image and transfer the image to a recording medium. In the image forming device, as the image forming unit, there are one image forming unit and another image forming unit. The one image forming unit forms an image of a developer of one color on the surface of the one image retaining body, and the other image forming unit is located on the downstream side of the one image forming unit, forms an image of a developer of another color on the surface of the other image retaining body, and includes a contact component whose front end portion contacts the surface of the other image retaining body after transfer.

[0193] According to (((1))), the occurrence of poor image quality can be suppressed compared to a situation in which, in another image forming unit located on the downstream side of an image forming unit that forms an image of a developer of one color and having another image retaining body that forms an image of a developer of another color, the developer of one color is not prevented from accumulating and forming a lump at the front end portion of a contact member that contacts the surface of the other image retaining body after transfer.

[0194] According to (((2))), the other image forming units are a plurality of other image forming units that form images of the respective developers of YMCK colors as images of the developer of another color, and the occurrence of poor image quality can be suppressed compared to a case where this structure is not provided.

[0195] According to (((3))), a predetermined frequency is set for each of the plurality of other image forming units, and the occurrence of poor image quality can be suppressed compared to a case where this configuration is not provided.

[0196] According to (((4))), the preset frequency decreases as the frequency progresses toward the downstream side in the plurality of other image forming units, and consumption of the developer of the other color can be suppressed compared to a case where this configuration is not provided.

[0197] According to (((5))), the preset frequency is set based on the information indicating the usage amount of the developer of one color, and the occurrence of poor image quality can be suppressed compared to a case where this configuration is not provided.

[0198] According to (((6))), the pre-set image includes a developer portion extending along the axial direction of another image retaining body and a non-developer portion arranged between the developer portions separated from each other in a direction intersecting the axial direction, which can suppress the occurrence of poor image quality compared to a case without this structure.

[0199] According to (((7))), the amount of developer portion decreases as it proceeds toward the downstream side when the other image forming unit is a plurality of image forming units, and consumption of the developer of the other color can be suppressed compared to a case where this structure is not provided.

[0200] According to (((8))), one image forming unit does not form a preset image, and the consumption of developer of one color can be suppressed compared to a case where this configuration is not provided.

[0201] According to (((9))), the occurrence of poor image quality can be suppressed compared to a situation in which, in another image forming unit located on the downstream side of an image forming unit that forms an image of a developer of one color and having another image retaining body that forms an image of a developer of another color, the developer of one color is not prevented from accumulating and forming a lump at the front end portion of a contact member that contacts the surface of the other image retaining body after transfer.

Claims

1. An image forming device comprising a plurality of image forming units along one direction for forming an image by attaching a developer to a surface of an image holding member and transferring the image to a recording medium, characterized in that: The image forming unit includes an image forming unit and another image forming unit, wherein the image forming unit forms an image of a developer of one color on the surface of an image holding body, and the other image forming unit is located on the downstream side of the image forming unit, forms an image of a developer of another color on the surface of another image holding body, and includes a contact member whose front end portion contacts the surface of the other image holding body after transfer. In the image forming device, the developer of the other color is attached to the surface of the other image retaining body to form a predetermined image, and the image of the surface is passed between the transferred surface and the front end of the contact member at a predetermined frequency.

2. The image forming apparatus according to claim 1, wherein: The other image forming units are a plurality of other image forming units that form images of the developers of YMCK colors as images of the developer of the other color.

3. The image forming apparatus according to claim 2, wherein: The preset frequency is set for each of the plurality of other image forming units.

4. The image forming apparatus according to claim 3, wherein: The preset frequency decreases in the plurality of another image forming units as progressing toward the downstream side.

5. The image forming apparatus according to claim 3, wherein: The preset frequency is set based on information indicating the usage amount of developer of one color.

6. The image forming apparatus according to any one of claims 1 to 5, wherein: The predetermined image includes a developer portion extending in the axial direction of the other image holding member and a non-developer portion provided between the developer portions separated from each other in a direction intersecting the axial direction.

7. The image forming apparatus according to claim 6, wherein: The number of the developer portion decreases as proceeding toward the downstream side in a case where the another image forming unit is a plurality of image forming units.

8. The image forming apparatus according to any one of claims 1 to 7, wherein: The one image forming unit does not form the preset image.

9. A computer-readable medium storing a program for causing a computer controlling an image forming apparatus to execute a process, the image forming apparatus comprising a plurality of image forming units along one direction for causing a developer to adhere to a surface of an image retaining body to form an image and transfer the image to a recording medium, the image forming units comprising one image forming unit and another image forming unit, the one image forming unit forming an image of a developer of one color on the surface of the one image retaining body, the other image forming unit being located on the downstream side of the one image forming unit, forming an image of a developer of another color on the surface of the other image retaining body, and comprising a contact member having a front end portion in contact with the surface of the other image retaining body after the transfer, the computer-readable medium being characterized in that the process comprises: a step of acquiring the number of times an image of a developer of one color is formed by the one image forming unit; and When the acquired number of times satisfies a preset condition, the developer of the other color is attached to the surface of the other image retaining member to form a preset image, and a process is performed to make the image on the surface pass between the front end portion of the contact member.

10. An image forming method, which is an image forming method of an image forming device, wherein the image forming device has a plurality of image forming units along one direction for causing a developer to adhere to a surface of an image retaining body to form an image and transfer the image to a recording medium, and as the image forming units, the image forming unit and the other image forming unit are provided, wherein the one image forming unit forms an image of a developer of one color on the surface of the one image retaining body, and the other image forming unit is located on the downstream side of the one image forming unit, forms an image of a developer of another color on the surface of the other image retaining body, and includes a contact member whose front end portion contacts the surface of the other image retaining body after the transfer, wherein the image forming method is characterized in that: The developer of the other color is attached to the surface of the other image holding member to form a predetermined image, and the image on the surface is passed between the transferred surface and the front end of the contact member at a predetermined frequency.

Images