Image forming apparatus, control method thereof, and computer readable medium

Abstract

An image forming apparatus, a method of controlling the same, and a computer readable medium perform a first operation of forming an image by a first developer held by a first developer holding body and a second operation of forming an image by a second developer held by a second developer holding body, the first developer is a developer of one color conveyed by the first conveying unit, the second developer is a developer of another color conveyed by the second conveying unit, and the rotational speed of the first developer holding body and the rotational speed of the second developer holding body are first rotational speed. A conveying speed at which the first conveying unit conveys the first developer and a conveying speed at which the second conveying unit conveys the second developer are a first conveying speed, a rotation speed of the first developer holding body and a rotation speed of the second developer holding body are smaller than the first rotation speed, and the conveying speed at which the first conveying unit conveys the first developer is smaller than the first conveying speed. A conveying speed at which the second conveying unit conveys the second developer is greater than the second conveying speed.

Description

Technical Field

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

[0002] For example, Japanese Patent Gazette No. 2010-151974 discloses an image forming device, which is characterized in that it comprises: an image carrier that is rotationally driven and has an electrostatic latent image corresponding to image information formed on its surface; a color developing unit that develops the electrostatic latent image formed on the image carrier while stirring a two-component developer consisting of a colored toner and a carrier by a stirring unit; and a transparent developing unit that develops the electrostatic latent image formed on the image carrier while stirring the two-component developer consisting of a transparent toner and a carrier by a stirring unit whose stirring capacity is set smaller than that of the color developing unit. Summary of the invention

[0003] Here, an image forming apparatus is provided, which is capable of performing a first action of forming an image by a first developer held by a rotating first developer holding body and a second action of forming an image by a second developer held by a rotating second developer holding body, the first developer being a developer of one color conveyed by a first conveying unit and the second developer being a developer of another color conveyed by a second conveying unit, wherein a structure is considered in which the rotation speed of the first developer holding body and the rotation speed of the second developer holding body are lowered than those in the first action in the second action. In the case where the conveying speed of the first conveying unit and the conveying speed of the second conveying unit are lowered than those in the first action as the rotation speed is lowered in the second action, when the second developer is more difficult to charge than the first developer, the second developer in a state of low charge amount may be supplied to the second developer holding body.

[0004] An object of the present invention is to suppress the reduction in the charge amount of the second developer, compared to a situation where the rotational speed of the first developer retaining body and the rotational speed of the second developer retaining body in the second action are lower than those in the first action, and thus the conveying speed of the second conveying unit for conveying the second developer is lower than that in the first action.

[0005] According to a first aspect of the present invention, there is provided an image forming apparatus capable of performing a first action of forming an image by a first developer held by a rotating first developer holding body and a second action of forming an image by a second developer held by a rotating second developer holding body, the first developer being a developer of one color conveyed by a first conveying unit and the second developer being a developer of another color conveyed by a second conveying unit, the image forming apparatus being characterized in that:

[0006] In the first action, the rotation speed of the first developer holding body and the rotation speed of the second developer holding body are the first rotation speed, the conveying speed of the first conveying unit conveying the first developer and the conveying speed of the second conveying unit conveying the second developer are the first conveying speed,

[0007] In the second action, the rotational speed of the first developer retaining body and the rotational speed of the second developer retaining body are second rotational speeds smaller than the first rotational speed, the conveying speed of the first developer conveyed by the first conveying unit is a second conveying speed smaller than the first conveying speed, and the conveying speed of the second developer conveyed by the second conveying unit is a conveying speed greater than the second conveying speed.

[0008] According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the conveyance of the second developer by the second conveying unit is performed by a driving source different from a driving source for rotating the second developer holding body.

[0009] According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, a conveying speed at which the second conveying unit conveys the second developer in the second operation is determined based on the first conveying speed.

[0010] According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, a conveying speed at which the second conveying unit conveys the second developer in the second operation is the same as the first conveying speed.

[0011] According to a fifth aspect of the present invention, in the image forming apparatus according to the third aspect, a conveying speed at which the second conveying unit conveys the second developer in the second operation is lower than the first conveying speed.

[0012] According to a sixth aspect of the present invention, in the image forming apparatus according to the third aspect, a conveying speed at which the second conveying unit conveys the second developer in the second operation is greater than the first conveying speed.

[0013] According to the seventh aspect of the present invention, in the image forming device based on any one of the third to sixth aspects, the conveying speed of the first conveying unit and the conveying speed of the second conveying unit do not change during the period from the start to the stop of the rotation of the first developer retaining body and the second developer retaining body.

[0014] According to an eighth aspect of the present invention, in the image forming apparatus according to the first or second aspect, a conveying speed at which the second conveying unit conveys the second developer in the second operation is determined according to the second developer.

[0015] According to a ninth aspect of the present invention, in the image forming apparatus according to the eighth aspect, a conveying speed at which the second conveying unit conveys the second developer in the second operation is determined based on information indicating ease of charging the second developer.

[0016] According to a tenth aspect of the present invention, there is provided a computer-readable medium storing a program for causing a computer controlling an image forming device to execute processing, wherein the image forming device is capable of performing a first action of forming an image by a first developer held by a rotating first developer holding body and a second action of forming an image by a second developer held by a rotating second developer holding body, the first developer being a developer of one color conveyed by a first conveying unit, and the second developer being a developer of another color conveyed by a second conveying unit, the computer-readable medium being characterized in that the processing has the following steps: in the first action, control is performed such that: the rotation speed of the first developer holding body and the rotation speed of the second developer holding body are a first rotation speed, and the conveying speed of the first conveying unit conveying the first developer and the conveying speed of the second conveying unit conveying the second developer are a first conveying speed; and in the second action, control is performed such that: the rotation speed of the first developer holding body and the rotation speed of the second developer holding body are a second rotation speed smaller than the first rotation speed, the conveying speed of the first conveying unit conveying the first developer is a second conveying speed smaller than the first conveying speed, and the conveying speed of the second conveying unit conveying the second developer is a conveying speed greater than the second conveying speed.

[0017] According to the eleventh aspect of the present invention, there is provided a method for controlling an image forming device, wherein the image forming device is capable of performing a first action of forming an image by a first developer held by a rotating first developer holding body and a second action of forming an image by a second developer held by a rotating second developer holding body, wherein the first developer is a developer of one color conveyed by a first conveying unit, and the second developer is a developer of another color conveyed by a second conveying unit, and the method for controlling the image forming device is characterized in that it has the following steps: in the first action, control is performed such that: the rotation speed of the first developer holding body and the rotation speed of the second developer holding body are a first rotation speed, and the conveying speed of the first conveying unit conveying the first developer and the conveying speed of the second conveying unit conveying the second developer are a first conveying speed; and in the second action, control is performed such that: the rotation speed of the first developer holding body and the rotation speed of the second developer holding body are a second rotation speed smaller than the first rotation speed, the conveying speed of the first conveying unit conveying the first developer is a second conveying speed smaller than the first conveying speed, and the conveying speed of the second conveying unit conveying the second developer is a conveying speed greater than the second conveying speed.

[0018] (Effect)

[0019] According to the first and eleventh aspects, the reduction in the charge amount of the second developer can be suppressed compared to the situation where the rotational speed of the first developer retaining body and the rotational speed of the second developer retaining body in the second action are lower than those in the first action, and the conveying speed of the second conveying unit for conveying the second developer is lower than that in the first action.

[0020] According to the second aspect, the structure can be simplified compared to a case where the second developer conveying unit does not have a structure in which conveying of the second developer is performed by a driving source different from a driving source for rotating the second developer holding member.

[0021] According to the third aspect, control can be simplified compared to a case where the conveying speed of the second developer conveyed by the second conveying unit in the second operation is not determined based on the first conveying speed.

[0022] According to the fourth aspect, the structure can be simplified compared to a case where the structure in which the conveying speed of the second developer conveyed by the second conveying unit in the second operation is equal to the first conveying speed.

[0023] According to the fifth aspect, the charge amount of the second developer can be ensured compared to a case where the second conveying unit in the second operation conveys the second developer at a speed lower than the first conveying speed.

[0024] According to the sixth aspect, compared with a case where the second developer is not transported at a higher speed than the first transport speed by the second transport unit in the second operation, the charge amount of the second developer can be ensured.

[0025] According to the seventh aspect, compared with a structure in which the conveying speed of the first conveying unit and the conveying speed of the second conveying unit do not change during the period from the start of rotation to the stop of the first developer retaining body and the second developer retaining body, uneven existence of the first developer in the first conveying unit and the second developer in the second conveying unit can be prevented.

[0026] According to the eighth aspect, compared with a case where the conveying speed of the second developer conveyed by the second conveying unit in the second operation is not determined according to the second developer, the charge amount of the second developer can be ensured.

[0027] According to the ninth aspect, the charged amount of the second developer can be ensured compared to a case where the conveying speed of the second developer conveyed by the second conveying unit in the second operation is not determined based on information indicating the ease of charging the second developer.

[0028] According to the tenth aspect, the reduction in the charge amount of the second developer can be suppressed compared to a situation where the rotational speed of the first developer retaining body and the rotational speed of the second developer retaining body in the second action are lower than those in the first action, and the conveying speed of the second conveying unit for conveying the second developer is lower than that in the first action. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a diagram for explaining the image forming apparatus.

[0030] Figure 2 This is a diagram for explaining a developing device of an image forming apparatus.

[0031] Figure 3 These are diagrams for explaining the developing unit of the image forming apparatus according to the first embodiment, wherein (a) shows a developing unit and (b) shows another developing unit.

[0032] Figure 4 It is a diagram showing a configuration example of hardware of a control unit of the image forming apparatus.

[0033] Figure 5 This is a block diagram for explaining the functional configuration of the control unit according to the first embodiment.

[0034] Figure 6 This is a flowchart showing an example of a processing procedure for controlling the speed of the conveying portion of the developing device when a print job is received in the first embodiment.

[0035] Figure 7 This is a table showing an example of the speed in the developing device according to the first embodiment.

[0036] Figure 8 These are diagrams for explaining a developing unit of an image forming apparatus according to a second embodiment, wherein (a) shows a developing unit and (b) shows another developing unit.

[0037] Fig. 9 This is a block diagram for explaining the functional configuration of the control unit according to the second embodiment.

[0038] Fig.10 This is a flowchart showing an example of a processing procedure for controlling the conveying portion of the developing device and the speed of the conveying portion of the developing device when a print job is received in the second embodiment.

[0039] Fig.11 This is a table showing an example of the speed in the developing device according to the second embodiment. DETAILED DESCRIPTION

[0040] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0041] Figure 1 It is a diagram for explaining the image forming apparatus 1 .

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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 .

[0046] 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 .

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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 .

[0055] 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 .

[0056] 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 .

[0057] 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.

[0058] The developing device 33 is an example of a developing unit, the intermediate transfer belt 41 is an example of a transfer unit, and the fixing device 80 is an example of a fixing unit.

[0059] The image forming section 20 performs an image forming operation based on a control signal from the control section 21 .

[0060] 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 .

[0061] 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 .

[0062] Thus, an electrostatic latent image is formed on the photosensitive drum 31 .

[0063] The formed electrostatic latent image is developed by the developing device 33 , and a magenta toner image is formed on the photosensitive drum 31 .

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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 .

[0070] Thereafter, the paper P to which the superimposed toner images are electrostatically transferred is conveyed to the fixing device 80 .

[0071] 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.

[0072] 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).

[0073] 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.

[0074] like Figure 2 As shown, the developer 33 has a storage section 331 for storing a developer (not shown) therein. The storage section 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. In addition, it is also conceivable to set the developer as a single-component developer.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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 .

[0082] In addition, if Figure 2 As shown in FIG. 1 , a first conveying portion 337 and a second conveying portion 338 for conveying the developer are provided in the developing device 33. Hereinafter, the first conveying portion 337 and the second conveying portion 338 may be referred to as conveying portions 337 to 338.

[0083] The conveying sections 337 to 338 are provided at a position close to the photosensitive drum 31 (see Figure 1 ) is on the side opposite to the setting side.

[0084] The conveying parts 337 to 338 are respectively provided with rotating members 52 and 53 extending along the rotating shaft of the developing sleeve 334G which is driven to rotate, and rotate around the rotating members 52 to 53. That is, the conveying parts 337 to 338 are arranged to be close to the photosensitive drum 31 (see Figure 1 ) are roughly parallel.

[0085] The rotating member 52 is a so-called Admix auger that stirs the developer, and the rotating member 53 is a so-called Supply auger that supplies the developer to the developing roller 334 .

[0086] Next, the rotation speeds of the developing roller 334 and the rotating members 52 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 52 to 53 is sometimes referred to as the speed of the conveying sections 337 to 338.

[0087] Next, a first embodiment and a second embodiment will be described.

[0088] <First Embodiment>

[0089] First, the first embodiment will be described.

[0090] Figure 31 and 12 are diagrams for explaining the developing devices 33A and 33B of the image forming apparatus 1 according to the first embodiment. (a) shows the developing device 33A, and (b) shows the other developing device 33B.

[0091] In addition, the basic structure of the developers 33A and 33B is the same, but for the sake of convenience, symbols are used to indicate which of the developers 33A and 33B the structure belongs to. That is, the structure of the developer 33A is marked with "A" at the end of the symbol, and the structure of the developer 33B is marked with "B" at the end of the symbol. Figure 3 In Figure 2 The structures described in the figure are sometimes omitted from illustration and description.

[0092] Figure 3 The developing device 33A shown in (a) includes the above-mentioned image forming units 30Y, 30M, 30C, 30K, 30P, and 30T (see Figure 1 ) in the image forming units 30Y, 30M, 30C, and 30K, forming yellow, magenta, cyan, and black toner images. Figure 3 The developing device 33B shown in (b) includes image forming units 30P and 30T, and forms a toner image of a specific color.

[0093] To further explain, Figure 3 As shown in (a) of FIG. 8 , in the developer 33A, the developing sleeve 334G of the developing roller 334A and the rotating members 52A and 53A of the conveying portions 337A and 338A are rotationally driven by a driving source 61 .

[0094] In addition, if Figure 3 As shown in (b), in the developer 33B, the developing sleeve 334G of the developing roller 334B is rotationally driven by a driving source 61, and on the other hand, the rotating parts 52B and 53B of the conveying parts 337B and 338B are rotationally driven by a driving source 62 different from the driving source 61.

[0095] Therefore, the developing roller 334A and the rotating members 52A to 53A of the conveying sections 337A to 338A of the developing device 33A rotate at different speeds but at a preset ratio from the developing roller 334B of the developing device 33B. In addition, the rotating members 52B to 53B of the conveying sections 337B to 338B of the developing device 33B can rotate at a different ratio from the rotating members 52A to 53A of the conveying sections 337A to 338A of the developing device 33A.

[0096] Here, Figure 3 The driving source 61 shown in (b) drives the developing roller 334B and is an example of a driving source for rotating the second developer holding member. Figure 3The driving source 62 shown in (b) drives the rotating members 52B to 53B of the transmission units 337B to 338B and is an example of another driving source that drives the second rotating member.

[0097] In the first embodiment, the developer 33B is provided with two drive sources 61 and 62, but the drive source 62 for driving the rotating members 52B to 53B may be omitted and the rotating members 52B to 53B may be driven by the drive source 61. That is, the drive source 61 may be configured to drive the rotating members 52B to 53B by changing the speed through a reduction gear, for example.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] The calculation processing unit 21 a is provided with a CPU 21 b as an example of a processor.

[0102] 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 .

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] In this specification, the processor refers to a processor in a broad sense, including general-purpose processors (such as CPU: Central Processing Unit, etc.), special-purpose processors (such as GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0108] 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.

[0109] Figure 5 This is a block diagram for explaining the functional configuration of the control unit 21 according to the first embodiment.

[0110] exist Figure 5 In the example shown, the control unit 21 includes a special color printing determination unit 91, a speed determination unit 92, and drive source control units 93 and 94. The special color printing determination unit 91 and the like are controlled by a CPU 21b (see Figure 4 )accomplish.

[0111] In addition, Figure 5 The driving sources 61 and 62 located outside the control unit 21 are the above-mentioned Figure 3 The driving sources 61 and 62 of (a) and (b) are shown in FIG.

[0112] The special color printing determination unit 91 determines whether the print job received by the image forming apparatus 1 is a job for forming a toner image of a special color. That is, the special color printing determination unit 91 determines, based on the print job, whether only toner images of yellow (Y), magenta (M), cyan (C), and black (K) are formed without forming a toner image of a special color, or whether toner images of yellow (Y), magenta (M), cyan (C), and black (K) and a toner image of a special color are formed.

[0113] The speed determination unit 92 determines the speed of the rotating members 52B to 53B of the conveying units 337B to 338B in the developing unit 33B according to whether the printing is special color printing using special color toner. The speed is a speed corresponding to the upper limit of the number of sheets output per minute (ppm), that is, a processing speed, but is not limited to this, and may also be a specific rotation speed of the rotating members 52B to 53B.

[0114] More specifically, for example, in ROM 21d (see Figure 4 ) stores information indicating a preset speed for special color printing, when the judgment result of the special color printing judgment unit 91 is special color printing, the speed determination unit 92 reads the information indicating the speed from ROM 21d as the determined speed.

[0115] In addition, the speed of the conveying units 337B to 338B when not printing in special colors is not determined by the speed determination unit 92 but is a normal speed set in advance, but the present invention is not limited to this and a method determined by the speed determination unit 92 is also conceivable.

[0116] Incidentally, the speed of the developing roller 334A and the conveying parts 337A to 338A of the developing unit 33A and the speed of the developing roller 334B of the developing unit 33B are set to the same speed in advance in both the case of special color printing and the case of special color printing, and are not determined by the speed determination unit 92, but the present invention is not limited to this. That is, in the case where the speeds of the developing rollers 334A, 334B and the conveying parts 337A to 338A are different depending on whether special color printing is performed, it is also conceivable that the speed determination unit 92 determines the speeds depending on whether special color printing is performed.

[0117] The driving source control section 93 is a control section that controls the driving source 61. That is, the driving source control section 93 controls the driving source 61 so that the developing rollers 334A and 334B and the conveying sections 337A to 338A reach a preset speed.

[0118] The driving source control unit 94 is a control unit that controls the driving source 62. That is, the driving source control unit 94 controls the driving source 62 so that the conveying units 337B to 338B reach the speed determined by the speed determination unit 92.

[0119] Figure 6 This is a flowchart showing an example of a processing procedure for controlling the speed of the conveying units 337B to 338B of the developing device 33B when a print job is received in the first embodiment.

[0120] exist Figure 6 In the example shown, when a print job is received in the image forming apparatus 1 (step 101), the special color printing determination unit 91 (see Figure 4) Determine whether it is special color printing using special color toner (step 102).

[0121] If the received print job is special color printing (Yes in step 102), the speed determination unit 92 (see Figure 4 ) determines the conveying parts 337B to 338B of the developing device 33B (refer to Figure 3 (b)) speed (step 103).

[0122] By starting the image forming unit 20 after the determination (see Figure 1 ) action, the developing rollers 334A, 334B and the conveying parts 337A to 338A, 337B to 338B start to rotate. At this time, the driving source control unit 94 controls the driving of the driving source 62 so that the speed of the conveying parts 337B to 338B reaches the determined speed (step 104). The speed of the conveying parts 337B to 338B does not change until the printing job is completed. In other words, during the period from the start of the rotation of the developing rollers 334A, 334B to the stop, the speed of the conveying parts 337B to 338B does not change.

[0123] When the print job is not special color printing (No in step 102 ), the drive source control unit 94 controls the drive of the drive source 62 so that the conveying units 337B to 338B of the developer 33B reach a preset speed (step 104 ).

[0124] Figure 7 This is a table showing an example of the rotation speed and the conveying speed in the developing devices 33A and 33B according to the first embodiment.

[0125] exist Figure 7 The table shown is divided into the case of YMCK colors and the case of K color, and each is separated into special color printing and non-special color printing, and each rotation speed and each conveying speed in the developers 33A and 33B are shown.

[0126] The rotation speed of the developing roller 334A in the developing device 33A is synonymous with the rotation speed of the photosensitive drum 31 supplied with developer from the developing roller 334A, and the rotation speed of the developing roller 334B in the developing device 33B is synonymous with the rotation speed of the photosensitive drum 31 supplied with developer from the developing roller 334B.

[0127] The transport speed of the transport parts 337A to 338A in the developing device 33A is synonymous with the rotation speed of the rotating members 52A to 53A, and the transport speed of the transport parts 337B to 338B in the developing device 33B is synonymous with the rotation speed of the rotating members 52B to 53B.

[0128] like Figure 7As shown in FIG. 1 , the rotation speed is divided into "high speed" and "low speed", and the transmission speed is divided into "high speed" and "low speed". The "high speed" and "low speed" of the rotation speed mentioned here indicate the magnitude of the speed, and similarly, the "high speed" and "low speed" of the transmission speed indicate the magnitude of the speed. In showing an example of the rotation speed, when "high speed" is 85ppm, which means the output upper limit number of sheets per minute is 85 sheets, "low speed" is, for example, 40ppm.

[0129] In addition, the rotation speed "high speed" and the transmission speed "high speed" may be the same speed or different speeds. Similarly, the rotation speed "low speed" and the transmission speed "high speed" may be the same speed or different speeds.

[0130] When printing in YMCK colors and not special colors, the rotation speed of the developing roller 334A of the developer 33A and the conveying speed of the conveying parts 337A to 338A, and the rotation speed of the developing roller 334B of the developer 33B and the conveying speed of the conveying parts 337B to 338B are all high speed.

[0131] On the other hand, in the case of special color toners, such as gold toners containing aluminum alloy flakes, silver toners, and white toners that require a large amount of developer, it is necessary to increase the fixing temperature in order to cope with glossiness. Therefore, in the case of YMCK colors and special colors, the speeds of the developing rollers 334A, 334B and the conveying units 337A to 338A are low to ensure a high fixing temperature, whereas the speed of the conveying units 337B to 338B is high. In other words, in the image forming units 30T and 30P having the developer 33B, when performing special color printing, even if the photosensitive drum 31 (see Figure 1 ) and the developing roller 334B (refer to Figure 3 (b)) is decelerated compared to the case where special color printing is not performed, and the rotating parts 52B to 53B of the conveying parts 337B to 338B are not decelerated either.

[0132] Therefore, it is possible to suppress the charge amount of the developer containing the special color toner stirred and conveyed by the conveying portions 337B to 338B of the developer 33B from decreasing as the conveying speed of the conveying portions 337B to 338B becomes low.

[0133] That is, when performing special color printing, even if the rotation speeds of the developing roller 334A and the developing roller 334B are reduced, the reduction in the charge amount of the special color developer can be suppressed by reducing the transport speed of the transport section 337B~338B that transports the special color developer less than the reduction in the rotation speed of the developing roller 334B.

[0134] In the case of K color, when it is not a special color printing, the rotation speed of the developing rollers 334A, 334B and the conveying speed of the conveying parts 337A to 338A, 337B to 338B are high speeds, as in the case of YMCK colors. In the case of special color printing, the rotation speed of the developing rollers 334A, 334B and the conveying speed of the conveying parts 337A to 338A are low speeds, as in the case of YMCK colors, while the conveying speed of the conveying parts 337B to 338B is high speeds.

[0135] exist Figure 7 In the case of special color printing, the speed of the rotating parts 52B to 53B when the developing roller 334B rotates at a low speed is high, which is higher than the speed of the rotating parts 52A to 53A when the developing roller 334A rotates at a low speed, that is, the low speed.

[0136] In addition, Figure 7 In the figure, the rotating parts 52B to 53B rotate at high speed when the developing roller 334B rotates at high speed when printing a non-special color. That is, the rotating speed of the rotating parts 52B to 53B when the developing roller 334B rotates at high speed for printing a non-special color, i.e., the high speed, is the same as the rotating speed of the rotating parts 52B to 53B when the developing roller 334B rotates at low speed for printing a special color.

[0137] Here, in Figure 3 In the figure, the developing roller 334A of the developing device 33A is an example of a rotating first developer holding body, and the developing roller 334B of the developing device 33B is an example of a rotating second developer holding body. The conveying parts 337A to 338A of the developing device 33A are an example of a first conveying unit, and the conveying parts 337B to 338B of the developing device 33B are an example of a second conveying unit. In addition, the developer of YMCK color is an example of a first developer of one color, and the developer of a special color is an example of a second developer of another color.

[0138] Furthermore, the driving source 61 is an example of a driving source for rotating the second developer holding member, and the driving source 62 is an example of another driving source.

[0139] Figure 7 The "high speed" in the rotation speed is an example of the first rotation speed, and the "low speed" in the rotation speed is an example of the second rotation speed. Figure 7 The “high speed” of the transmission speed in is an example of the first transmission speed, and the “low speed” of the transmission speed is an example of the second transmission speed.

[0140] <Second Embodiment>

[0141] Next, the second embodiment will be described. In the second embodiment, the configurations of the image forming units 30Y, 30M, 30C, and 30K are similar to those of the first embodiment (see Figure 3 (a)) is the same as that of the first embodiment. On the other hand, the configurations of the image forming units 30T and 30P are the same as those of the first embodiment (see Figure 3 The following is a detailed description.

[0142] In addition, in the second embodiment, since there are common structures and controls with the first embodiment, their description may be omitted.

[0143] Figure 8 The drawings are for explaining the developing devices 33C and 33D of the image forming apparatus 1 according to the second embodiment, wherein (a) shows the developing device 33C, and (b) shows the other developing device 33D. Figure 8 The first embodiment is described Figure 3 The corresponding figure.

[0144] In the second embodiment, the developing device 33A described in the first embodiment (see Figure 3 (a)), but the developing device 33C and 33D are provided instead of the developing device 33B described in the first embodiment. That is, in the second embodiment, the developing devices 33A, 33C, and 33D are provided.

[0145] The basic structure of the developing devices 33C and 33D is similar to that of the developing device 33B (see Figure 3 (b)) is the same as that of the developing device 33C, but for the sake of convenience, symbols are used to indicate which of the developing devices 33C and 33D the structure belongs to. That is, the structure of the developing device 33C is marked with "C" at the end of the symbol, and the structure of the developing device 33D is marked with "D" at the end of the symbol.

[0146] Figure 8 The developing device 33C shown in (a) includes an image forming unit 30P, which forms a toner image of a special color. Figure 8 The developing device 33D shown in (b) includes an image forming unit 30T and forms a toner image of a specific color.

[0147] When further explaining, Figure 8 As shown in (a), in the developer 33C, the developing sleeve 334G of the developing roller 334C is rotationally driven by a driving source 61, and on the other hand, the rotating parts 52C and 53C of the conveying parts 337C and 338C are rotationally driven by a driving source 63 different from the driving source 61.

[0148] In addition, if Figure 8As shown in (b), in the developer 33D, the developing sleeve 334G of the developing roller 334D is rotationally driven by a driving source 61, and on the other hand, the rotating parts 52D and 53D of the conveying parts 337D and 338D are rotationally driven by a driving source 64 different from the driving source 61.

[0149] Therefore, the developing roller 334C of the developing device 33C and the developing roller 334D of the developing device 33D rotate at the same speed. The speed is the same as that of the developing roller 334A of the developing device 33A and the rotating members 52A to 53A of the conveying sections 337A to 338A (see Figure 3 The speed of (a) is the same.

[0150] In addition, the rotating members 52C to 53C of the conveying parts 337C to 338C of the developing device 33C can be connected to the rotating members 52A to 53A of the developing device 33A (see Figure 3 (a)) rotating at different speeds.

[0151] In addition, the rotating members 52D to 53D of the conveying sections 337D to 338D of the developing device 33D can be connected to the rotating members 52A to 53A of the developing device 33A (see Figure 3 (a)) and can rotate at a speed different from that of the rotating members 52C to 53C of the developing device 33C.

[0152] Here, Figure 8 The driving source 63 shown in (a) drives the rotating members 52C to 53C of the transmission parts 337C to 338C, and is an example of another driving source for driving the second rotating member. Figure 8 The driving source 64 shown in (b) drives the rotating members 52D to 53D of the conveying units 337D to 338D and is an example of another driving source that drives the second rotating member.

[0153] Fig. 9 is a block diagram for explaining the functional structure of the control unit 21 of the second embodiment, which is similar to the block diagram for explaining the first embodiment. Figure 5 The corresponding figure, sometimes omitted Figure 5 Description of the common structure.

[0154] exist Fig. 9 In the illustrated example, the control section 21 includes a special color printing determination section 91 , a special color toner information storage section 95 , a speed determination section 92 , and drive source control sections 93 , 96 , and 97 .

[0155] In addition, Fig. 9 The driving sources 63 and 64 located outside the control unit 21 are the above-mentioned Figure 8 The driving sources 63 and 64 of (a) and (b) are shown in FIG.

[0156] The special color toner information storage unit 95 stores special color toner information which is information indicating special color toners included in the developers 33C and 33D of the image forming units 30P and 30T.

[0157] The special color toner information is information required for the speed determination unit 92 to determine the speed. To further explain, the special color toner information is information for specifying which type of toner the special color toner of each of the developers 33C and 33D is, for example, gold toner, silver toner, white toner, etc. By using the special color toner information, the speeds of the rotating members 52C to 53C and 52D to 53D are determined according to the toner.

[0158] In addition, as special color toner information, information indicating physical property values ​​of toner components may be included in place of or together with specific toner names. The information indicating physical property values ​​is an example of information indicating charging ease. In addition, measurement values ​​obtained by pre-measurement may be used in place of information indicating physical property values.

[0159] The special color toner information mentioned here may be information stored in a storage medium (not shown) included in the developers 33C and 33D of the image forming units 30P and 30T.

[0160] The driving source control unit 96 is a control unit that controls the driving source 63. That is, the driving source control unit 96 controls the driving source 63 so that the conveying units 337C to 338C reach a preset speed.

[0161] The driving source control unit 97 is a control unit that controls the driving source 64. That is, the driving source control unit 97 controls the driving source 64 so that the conveying units 337D to 338D reach a preset speed.

[0162] Here, in Fig. 9 In the figure, the developing roller 334C of the developing device 33C and the developing roller 334D of the developing device 33D are examples of the second developer holding member that rotates. The conveying parts 337C to 338C of the developing device 33C and the conveying parts 337D to 338D of the developing device 33D are examples of the second conveying unit. In addition, the driving sources 63 and 64 are examples of another driving source.

[0163] Fig.11 "V11" in is an example of the first speed, and "V13" is an example of the second speed. Fig.11 "V21" in is an example of the first transmission speed, and "V23" is an example of the second transmission speed. Fig.11“V22” in FIG. 1 is an example of a conveyance speed of the second developer that is lower than the first conveyance speed, and “V20” is an example of a conveyance speed of the second developer that is higher than the first conveyance speed.

[0164] Fig.10 This is a flowchart showing an example of a processing procedure for controlling the speed of the transport units 337C to 338C of the developer 33C and the transport units 337D to 338D of the developer 33D when a print job is received in the second embodiment. Fig.10 This is the same as that described in the first embodiment. Figure 6 The corresponding figure, sometimes omitted Figure 6 Description of the common structure.

[0165] exist Fig.10 In the example shown, the special color printing determination unit 91 (see Fig. 9 ) Determine whether the accepted print job is a special color print using a special color toner (steps 201, 202).

[0166] When it is determined to be special color printing (YES in step 202 ), special color toner information stored in the special color toner information storage section 95 is read as information on special color toner used for special color printing (step 203 ).

[0167] The speed determination unit 92 (see Fig. 9 ) Based on the special color toner information read out, the conveying sections 337C to 338C of the developing device 33C are determined (see Figure 8 (a)) and the conveying parts 337D to 338D of the developing device 33D (refer to Figure 8 Then, the drive source control units 96 and 97 control the drive sources 63 and 64 so that the conveying units 337C to 338C and the conveying units 337D to 338D reach the determined speeds, respectively (step 205).

[0168] When the print job is not special color printing (No in step 202), the drive source control units 96 and 97 control the drive sources 63 and 64 so that the conveying units 337C to 338C and the conveying units 337D to 338D reach a preset speed (step 205).

[0169] Fig.11 This is a table showing an example of the speed in the developing devices 33A, 33C, and 33D of the second embodiment, which is similar to the table described in the first embodiment. Figure 7 The corresponding figure. Fig.11 In the text, the rotation speed and transmission speed are expressed as "high speed" and "low speed". Figure 7Different, V11 and V13 are used to represent the rotation speed, and V20, V21, V22, and V23 are used to represent the transmission speed. The magnitude relationship is V11>V13, V20>V21>V22>V23. For example, V20 corresponds to 85ppm, V11 and V21 correspond to 80ppm, V22 corresponds to 75ppm, and V13 and V23 correspond to 40ppm.

[0170] Fig.11 The special color P shown is a color based on the special color toner included in the developer 33C, and the special color T is a color based on the special color toner included in the developer 33D.

[0171] exist Fig.11 In the table shown, for YMCK colors, the speeds of the developers 33A, 33C, and 33D are shown for the cases where special color printing including special colors P and T is performed and the cases where special color printing is not performed.

[0172] To be specific, when printing in YMCK colors and not in special colors, the rotational speeds of the developing roller 334A of the developer 33A, the developing roller 334C of the developer 33C, and the developing roller 334D of the developer 33D are all speed V11, and the conveying speeds of the conveying parts 337A to 338A of the developer 33A, the conveying parts 337C to 338C of the developer 33C, and the conveying parts 337D to 338D of the developer 33D are all speed V21.

[0173] On the other hand, in the case of YMCK colors and special colors P and T, the rotation speed of the developing rollers 334A, 334C, and 334D is a speed V13 that is smaller than the speed V11 (V11>V13), and the conveying speed of the conveying parts 337A~338A is a speed V23 that is smaller than the speed V21 (V21>V23).

[0174] In contrast, the transmission speed of the transmission units 337C to 338C is a speed V20 greater than the transmission speed V21 (V20>V21), and the transmission speed of the transmission units 337D to 338D is a speed V22 less than the speed V21 and greater than the speed V23 (V21>V22>V23). In this way, the transmission speeds V20 of the transmission units 337C to 338C and the transmission speeds V22 of the transmission units 337D to 338D are determined based on the speed V21.

[0175] Thus, in the second embodiment, the conveying speed of the conveying parts 337C to 338C of the developing device 33C and the conveying speed of the conveying parts 337D to 338D of the developing device 33D are set to be different from each other. That is, by changing the speed of stirring the special color toner according to the type of the special color toner, the charge amount of the special color toner of the developing device 33C and the charge amount of the special color toner of the developing device 33D are ensured.

[0176] In addition, Fig.11 , the case of YMCK colors and special colors P and T is shown, but the present invention is not limited to this, and in other cases, namely, the case of YMCK colors and special color P, and the case of YMCK and special color T, it is also considered to set the same speed.

[0177] <Note> (((1)))

[0179] An image forming device capable of performing a first action of forming an image by a first developer held by a rotating first developer holding body and a second action of forming an image by a second developer held by a rotating second developer holding body, wherein the first developer is a developer of one color conveyed by a first conveying unit and the second developer is a developer of another color conveyed by a second conveying unit, the image forming device being characterized in that:

[0180] In the first action,

[0181] The rotation speed of the first developer holding body and the rotation speed of the second developer holding body are a first rotation speed,

[0182] A conveying speed at which the first conveying unit conveys the first developer and a conveying speed at which the second conveying unit conveys the second developer are a first conveying speed,

[0183] In the second action,

[0184] The rotation speed of the first developer holding member and the rotation speed of the second developer holding member are second rotation speeds that are smaller than the first rotation speed.

[0185] The first conveying unit conveys the first developer at a second conveying speed that is smaller than the first conveying speed, and the second conveying unit conveys the second developer at a conveying speed that is larger than the second conveying speed. (((2)))

[0187] The image forming apparatus according to (((1))) is characterized in that:

[0188] The conveyance of the second developer by the second conveying unit is performed by a driving source different from a driving source that rotates the second developer holding body. (((3)))

[0190] The image forming apparatus according to (((1))) or (((2))), characterized in that:

[0191] A conveying speed at which the second conveying unit conveys the second developer in the second operation is determined based on the first conveying speed. (((4)))

[0193] The image forming device according to (((3))) is characterized in that:

[0194] A conveying speed at which the second developer is conveyed by the second conveying unit in the second operation is the same as the first conveying speed. (((5)))

[0196] The image forming device according to (((3))) is characterized in that:

[0197] A conveying speed at which the second conveying unit conveys the second developer in the second operation is lower than the first conveying speed. (((6)))

[0199] The image forming device according to (((3))) is characterized in that:

[0200] The second conveying unit in the second operation conveys the second developer at a speed faster than the first conveying speed. (((7)))

[0202] The image forming apparatus according to any one of (((3))) to (((6))), characterized in that:

[0203] The conveying speed of the first conveying unit and the conveying speed of the second conveying unit do not change during a period from when the first developer holding member and the second developer holding member start to when they stop rotating. (((8)))

[0205] The image forming apparatus according to (((1))) or (((2))), characterized in that:

[0206] A conveying speed at which the second conveying unit conveys the second developer in the second operation is determined according to the second developer. (((9)))

[0208] The image forming device according to (((8))) is characterized in that:

[0209] A conveying speed at which the second conveying unit conveys the second developer in the second operation is determined based on information indicating ease of charging the second developer. (((10)))

[0211] A program is executed by a processor controlling an image forming apparatus, the image forming apparatus being capable of performing a first operation of forming an image by a first developer held by a rotating first developer holding body and a second operation of forming an image by a second developer held by a rotating second developer holding body, the first developer being a developer of one color conveyed by a first conveying unit and the second developer being a developer of another color conveyed by a second conveying unit, the program causing the processor to implement the following steps:

[0212] In the first action, the control is:

[0213] The rotation speed of the first developer holding body and the rotation speed of the second developer holding body are a first rotation speed,

[0214] A conveying speed at which the first conveying unit conveys the first developer and a conveying speed at which the second conveying unit conveys the second developer are first conveying speeds; and

[0215] In the second action, the control is:

[0216] The rotation speed of the first developer holding member and the rotation speed of the second developer holding member are second rotation speeds that are smaller than the first rotation speed.

[0217] The first conveying unit conveys the first developer at a second conveying speed that is smaller than the first conveying speed, and the second conveying unit conveys the second developer at a conveying speed that is larger than the second conveying speed.

[0218] According to (((1))), the reduction in the charge amount of the second developer can be suppressed compared to a case where the rotational speed of the first developer retaining body and the rotational speed of the second developer retaining body in the second action are lower than those in the first action, and the conveying speed of the second conveying unit that conveys the second developer is lower than that in the first action.

[0219] According to (((2))), the structure can be simplified compared to a case where the second developer conveying unit does not have a structure in which conveying of the second developer is performed by a driving source different from a driving source for rotating the second developer holding member.

[0220] According to (((3))), control can be simplified compared to a case where the conveying speed of the second developer conveyed by the second conveying unit in the second operation is not determined based on the first conveying speed.

[0221] According to (((4))), the structure can be simplified compared to a case where the structure in which the conveying speed of the second developer conveyed by the second conveying unit in the second operation is equal to the first conveying speed is not provided.

[0222] According to (((5))), the charge amount of the second developer can be ensured compared to a case where the second conveying unit in the second operation conveys the second developer at a speed lower than the first conveying speed.

[0223] According to (((6))), the charge amount of the second developer can be ensured compared to a case where the second conveying unit in the second operation conveys the second developer at a speed faster than the first conveying speed.

[0224] According to (((7))), compared with a case where the conveying speed of the first conveying unit and the conveying speed of the second conveying unit do not change during the period from the start of rotation to the stop of the first developer retaining body and the second developer retaining body, uneven existence of the first developer in the first conveying unit and the second developer in the second conveying unit can be prevented.

[0225] According to (((8))), the charge amount of the second developer can be ensured compared to a case where the conveying speed of the second developer conveyed by the second conveying unit in the second operation is not determined according to the second developer.

[0226] According to (((9))), the charge amount of the second developer can be ensured compared to a case where the conveying speed of the second developer conveyed by the second conveying unit in the second operation is not determined based on information indicating the ease of charging of the second developer.

[0227] According to (((10))), the reduction in the charge amount of the second developer can be suppressed compared to a case where the rotational speed of the first developer retaining body and the rotational speed of the second developer retaining body in the second action are lower than those in the first action, and the conveying speed of the second conveying unit that conveys the second developer is lower than that in the first action.

Claims

1. An image forming device capable of performing a first action of forming an image by a first developer held by a rotating first developer holding body and a second action of forming an image by a second developer held by a rotating second developer holding body, the first developer being a developer of one color conveyed by a first conveying unit and the second developer being a developer of another color conveyed by a second conveying unit, the image forming device being characterized in that: In the first action, The rotation speed of the first developer holding body and the rotation speed of the second developer holding body are a first rotation speed, A conveying speed at which the first conveying unit conveys the first developer and a conveying speed at which the second conveying unit conveys the second developer are first conveying speeds, In the second action, The rotation speed of the first developer holding body and the rotation speed of the second developer holding body are second rotation speeds which are smaller than the first rotation speed. The first conveying unit conveys the first developer at a second conveying speed that is smaller than the first conveying speed, and the second conveying unit conveys the second developer at a conveying speed that is larger than the second conveying speed.

2. The image forming apparatus according to claim 1, wherein: The conveyance of the second developer by the second conveying unit is performed by a driving source different from a driving source that rotates the second developer holding body.

3. The image forming apparatus according to claim 1 or 2, wherein: A conveying speed at which the second conveying unit conveys the second developer in the second operation is determined based on the first conveying speed.

4. The image forming apparatus according to claim 3, wherein: A conveying speed at which the second developer is conveyed by the second conveying unit in the second operation is the same as the first conveying speed.

5. The image forming apparatus according to claim 3, wherein: A conveying speed at which the second conveying unit conveys the second developer in the second operation is lower than the first conveying speed.

6. The image forming apparatus according to claim 3, wherein: The second conveying unit in the second operation conveys the second developer at a speed faster than the first conveying speed.

7. The image forming apparatus according to any one of claims 3 to 6, wherein: The conveying speed of the first conveying unit and the conveying speed of the second conveying unit do not change during a period from when the first developer holding member and the second developer holding member start to when they stop rotating.

8. The image forming apparatus according to claim 1 or 2, wherein: A conveying speed at which the second conveying unit conveys the second developer in the second operation is determined according to the second developer.

9. The image forming apparatus according to claim 8, wherein: A conveying speed at which the second conveying unit conveys the second developer in the second operation is determined based on information indicating ease of charging the second developer.

10. A computer-readable medium storing a program for causing a computer controlling an image forming apparatus to execute processing, the image forming apparatus being capable of performing a first action of forming an image by a first developer held by a rotating first developer holding body and a second action of forming an image by a second developer held by a rotating second developer holding body, the first developer being a developer of one color conveyed by a first conveying unit and the second developer being a developer of another color conveyed by a second conveying unit, the computer-readable medium being characterized in that: The process has the following steps: In the first action, the control is: The rotation speed of the first developer holding body and the rotation speed of the second developer holding body are a first rotation speed, A conveying speed at which the first conveying unit conveys the first developer and a conveying speed at which the second conveying unit conveys the second developer are first conveying speeds; and In the second action, the control is: The rotation speed of the first developer holding body and the rotation speed of the second developer holding body are second rotation speeds which are smaller than the first rotation speed. The first conveying unit conveys the first developer at a second conveying speed that is smaller than the first conveying speed, and the second conveying unit conveys the second developer at a conveying speed that is larger than the second conveying speed.

11. A method for controlling an image forming apparatus, the image forming apparatus being capable of performing a first action of forming an image by a first developer held by a rotating first developer holding body and a second action of forming an image by a second developer held by a rotating second developer holding body, the first developer being a developer of one color conveyed by a first conveying unit and the second developer being a developer of another color conveyed by a second conveying unit, the method for controlling an image forming apparatus being characterized by comprising: In the first action, the control is: The rotation speed of the first developer holding body and the rotation speed of the second developer holding body are a first rotation speed, A conveying speed at which the first conveying unit conveys the first developer and a conveying speed at which the second conveying unit conveys the second developer are first conveying speeds; and In the second action, the control is: The rotation speed of the first developer holding body and the rotation speed of the second developer holding body are second rotation speeds which are smaller than the first rotation speed. The first conveying unit conveys the first developer at a second conveying speed that is smaller than the first conveying speed, and the second conveying unit conveys the second developer at a conveying speed that is larger than the second conveying speed.

Images