JP2012150174A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfactorily clean developer remaining outside of a sheet-form range of a cleaning object member.SOLUTION: An image forming device includes the cleaning object member (an intermediate transfer belt 12) for carrying the developer, a developer diffusion member (a toner diffusion member 33) for diffusing the developer remaining on the cleaning object member, and a cleaning member (a cleaning brush 36) for removing the developer diffused by the developer diffusion member onto the cleaning object member from the cleaning object member. The developer diffusion member is arranged at a position upstream from the cleaning member, and installed while inclining from a conveyance direction of the cleaning object member.

Description

  The present invention relates to an image forming apparatus that forms an image on a recording medium, and more particularly to an image forming apparatus that satisfactorily cleans a developer remaining at a position outside a sheet range on a member to be cleaned.

  2. Description of the Related Art Conventionally, in an image forming apparatus (particularly, an electrophotographic image forming apparatus), there is an apparatus that cleans a developer remaining on a member to be cleaned by a brush cleaning mechanism (see, for example, Patent Document 1). The brush cleaning mechanism is a mechanism that uses a cleaning brush as a cleaning member in order to achieve a long life of the cleaning member.

JP 2006-91554 A

  However, when a conventional image forming apparatus using a brush cleaning mechanism performs borderless printing, a large amount of developer remains at a position outside the sheet range on the member to be cleaned. There was a problem that it could not be cleaned well. “Borderless printing” means an operation of printing an image on the entire surface of a recording medium without providing a margin.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus that satisfactorily cleans a developer remaining at a position outside a sheet range on a member to be cleaned. To do.

  In order to achieve the object, the present invention is diffused by a member to be cleaned carrying a developer, a developer diffusing member that diffuses the developer remaining on the member to be cleaned, and the developer diffusing member. A cleaning member for removing the developer on the member to be cleaned from the member to be cleaned, the developer diffusing member being disposed at a position upstream of the cleaning member, and further It is set as the structure arrange | positioned so that it may incline with respect to the conveyance direction of a member.

  In general, in an image forming apparatus, when borderless printing is performed, a large amount of developer remains concentrated at the same location on the member to be cleaned (particularly around the outer shape of the recording medium). Therefore, in the image forming apparatus, the cleaning member comes into contact with the developer for a long time at the same location, and this reduces the cleaning efficiency of the cleaning member.

  On the other hand, this image forming apparatus has a developer diffusing member for diffusing the developer remaining on the member to be cleaned at a position upstream of the cleaning member. Moreover, the developer diffusing member is disposed so as to be inclined with respect to the conveying direction of the member to be cleaned. In this image forming apparatus, the developer diffusing member diffuses the developer remaining on the member to be cleaned until the developer reaches the cleaning member. Therefore, the image forming apparatus can satisfactorily clean the developer remaining at a position outside the sheet range on the member to be cleaned.

  According to the present invention, it is possible to provide an image forming apparatus that satisfactorily cleans the developer remaining at a position outside the sheet range on the member to be cleaned.

1 is a cross-sectional view illustrating a configuration of an image forming apparatus according to a first embodiment. FIG. 3 is a diagram illustrating a configuration of a developer diffusing member used in Embodiment 1. 6 is a diagram illustrating a configuration of a modified example of the developer diffusing member used in Embodiment 1. FIG. 1 is a block diagram illustrating a configuration of an image forming apparatus according to a first embodiment. FIG. 6 is a distribution diagram illustrating a residual state of residual developer during borderless printing. FIG. 3 is a diagram (1) showing a relationship between the length of residual developer and cleaning efficiency. FIG. 6 is a diagram (2) showing a relationship between the length of residual developer and cleaning efficiency. FIG. 3 is a distribution diagram illustrating a state of diffusion of residual developer in the image forming apparatus according to the first embodiment. FIG. 4 is a cross-sectional view illustrating a configuration of an image forming apparatus according to a second embodiment. FIG. 4 is a block diagram illustrating a configuration of an image forming apparatus according to a second embodiment. FIG. 10 is a diagram illustrating a moving range of a toner detection sensor used in Embodiment 2. 6 is a schematic diagram illustrating a configuration of a toner detection sensor used in Embodiment 2. FIG. FIG. 6 is a diagram illustrating a relationship between a remaining developer remaining amount and an output voltage of a toner detection sensor used in the second exemplary embodiment.

  Hereinafter, an embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings. Each figure is only schematically shown so that the present invention can be fully understood. Therefore, the present invention is not limited to the illustrated example. Moreover, in each figure, the same code | symbol is attached | subjected about the common component and the same component, and those overlapping description is abbreviate | omitted.

[Embodiment 1]
<Configuration of image forming apparatus>
The configuration of the image forming apparatus according to the first embodiment will be described below with reference to FIGS. FIG. 1 is a cross-sectional view illustrating the configuration of the image forming apparatus according to the first embodiment. FIG. 2 is a diagram showing the configuration of the developer diffusing member used in the first embodiment. FIG. 3 is a diagram illustrating a configuration of a modified example of the developer diffusing member used in the first embodiment. FIG. 4 is a block diagram illustrating a configuration of the image forming apparatus according to the first embodiment.

  The image forming apparatus 1 according to the first embodiment is an apparatus that forms an image on a recording medium by an electrophotographic process based on print data input from a host device such as a host computer (not shown). Examples of the image forming apparatus 1 include a printer, a facsimile machine, a copier, and an MFP. Note that “MFP” is an abbreviation for Multi Function Peripheral, and is an apparatus in which a facsimile function, a scanner function, a copy function, and the like are added to a printer.

  Here, the image forming apparatus 1 is assumed to be a tandem type intermediate transfer color printer. Hereinafter, the image forming apparatus 1 is referred to as “printer 1”. Here, a description is given assuming that the printer 1 prints a color image. Further, “upstream” and “downstream” described below are based on the conveyance direction of the paper P or the traveling (conveyance) direction of the intermediate transfer belt 12.

  In the configuration shown in FIG. 1, the intermediate transfer belt 12, the secondary transfer roller 22, the toner diffusing member 33, the cleaning brush 36, and the collection roller 38 are each “the member to be cleaned” described in the claims. ”,“ Transfer member ”,“ developer diffusion member ”,“ cleaning member ”, and“ collecting member ”.

(Configuration of mechanism of image forming apparatus)
First, the structure of the mechanism system of the printer 1 will be described with reference to FIGS.
As shown in FIG. 1, the printer 1 has a stacker 31 at the top of the housing. The stacker 31 is a stacking unit that stacks printed sheets P. Further, the printer 1 includes a conveyance path 14, a paper feed mechanism Me1, a printing mechanism Me2, a transfer mechanism Me3, a fixing mechanism Me4, and a cleaning mechanism Me5 inside the casing.

  The conveyance path 14 is a path through which the paper P as a recording medium is conveyed. The conveyance path 14 is configured by a substantially flat surface of the guide 19. The guide 19 is a member that guides the paper P to a predetermined position. In the example illustrated in FIG. 1, the guide 19 includes three types of guides 19A, 19B, and 19C. The guide 19A is provided between the pinch roller 17 and the secondary transfer counter roller 23, and between the registration roller 18 and the secondary transfer roller 22. The guide 19B is provided between the secondary transfer roller 22 and the pressure roller 27. The guide 19 </ b> C is provided between the heat roller 26 and the stacker 31 and between the pressure roller 27 and the stacker 31.

  The paper feed mechanism Me1 is a mechanism that supplies the paper P to the transfer mechanism Me3. Here, “paper P” is described as a recording medium onto which a developer image is finally transferred. The paper feed mechanism Me1 includes a paper storage cassette 15, a hopping roller 16, a pinch roller 17, a registration roller 18, a guide 19A, and a paper feed sensor 21.

The paper storage cassette 15 is a storage unit that stores the paper P.
The hopping roller 16 is a member that feeds the paper P from the paper storage cassette 15 to the transport path 14. The hopping roller 16 is provided at a position directly above the paper feed opening of the paper storage cassette 15. The hopping roller 16 is driven to rotate by a hopping motor 45 (see FIG. 4).

  The pinch roller 17 is a member that corrects the skew of the paper P when the paper P is skewed. Note that “skew” means a state in which the paper P is fed obliquely. The pinch roller 17 is provided on the downstream side of the hopping roller 16.

  The registration roller 18 is a member that feeds the paper P to the secondary transfer roller 22. The registration roller 18 is provided on the downstream side of the hopping roller 16 so as to face the pinch roller 17 through the conveyance path 14. The registration roller 18 is driven to rotate by a registration motor 46 (see FIG. 4).

The guide 19 </ b> A is a member that guides the paper P to the secondary transfer roller 22.
The paper feed sensor 21 is a sensor for monitoring whether or not the paper P has reached between the pinch roller 17 and the registration roller 18. The paper feed sensor 21 is provided at a position immediately before the paper P in the transport direction with respect to the pinch roller 17 and the registration roller 18.

  In the paper feed mechanism Me1, the hopping roller 16 feeds the paper P from the paper storage cassette 15 to the transport path 14 during printing. A paper feed sensor 21 is provided on the downstream side of the hopping roller 16. The paper feed sensor 21 monitors whether or not the paper P has reached between the pinch roller 17 and the registration roller 18. When the paper P reaches between the pinch roller 17 and the registration roller 18, the pinch roller 17 corrects the skew of the paper P. Then, the registration roller 18 feeds the paper P to the guide 19 </ b> A and transports the paper P to the positions of the secondary transfer roller 22 and the secondary transfer counter roller 23.

  The printing mechanism Me2 is an image forming process unit that forms an image with a developer. The printing mechanism Me2 is configured to be freely attached to and detached from the printer 1. The printing mechanism Me2 includes a charging roller 3, a photosensitive drum 4, a developing roller 5, a developing blade 6, a supply roller 7, a static elimination light source 8, a toner cartridge 9, and an LED head 11. However, the LED head 11 may be an independent component separate from the printing mechanism Me2.

The charging roller 3 is a member that uniformly charges the surface of the photosensitive drum 4. The charging roller 3 rotates with the photosensitive drum 4.
The photosensitive drum 4 is an image carrier that carries an image. The photosensitive drum 4 has a configuration in which a cylindrical photosensitive member layer (not shown) made of an organic optical semiconductor is provided on the surface of a cylindrical shaft (not shown). The photosensitive drum 4 is driven to rotate by a drum motor 48 (see FIG. 4). At this time, the surface of the photosensitive drum 4 is uniformly charged by the charging roller 3 and then partially exposed by the LED head 11. Thereby, an electrostatic latent image is formed on the surface of the photosensitive drum 4.

  The developing roller 5 is a member that develops an electrostatic latent image formed on the photosensitive drum 4 as a developer image (hereinafter referred to as “toner image”) with a developer (hereinafter referred to as “toner TN”). is there. The developing roller 5 constitutes a developing unit together with the developing blade 6 and the supply roller 7.

The developing blade 6 is a member that adjusts the layer thickness of the toner TN supplied to the developing roller 5 by the supply roller 7 to be constant. The developing blade 6 is formed by polishing a metal such as stainless steel, and is provided along the axial direction of the developing roller 5 so that the tip is in contact with the developing roller 5 in parallel.
The supply roller 7 is a member that supplies the toner TN to the developing roller 5.

The static elimination light source 8 is an exposure unit that eliminates static electricity by exposing the surface of the photosensitive drum 4.
The toner cartridge 9 is a storage unit that stores the toner TN supplied to the development unit (the development roller 5, the development blade 6, and the supply roller 7). The toner TN supplied to the developing unit is supplied to the developing roller 5 by the supply roller 7 and adheres to the surface of the developing roller 5. The toner TN adhering to the surface of the developing roller 5 is adjusted to a constant layer thickness by the developing blade 6.

  The LED head 11 partially exposes the surface of the photosensitive drum 4 according to image data acquired from print data input from a host device such as a host computer (not shown), and electrostatic latent image is formed on the surface of the photosensitive drum 4. An exposure apparatus for forming an image. The LED head 11 includes an LED array (not shown), a drive IC, a substrate, and a selfoc lens array. The LED array is exposure means in which light emitting elements are integrated. The drive IC is a driving unit that drives the LED array. The substrate is a member on which a register group that holds image data is mounted. The Selfoc lens array is a member that collects the light from the LED array.

  The LED head 11 receives an image data signal of a corresponding color among color image data signals acquired from print data by the command / image processing unit 42 (see FIG. 4). The LED head 11 emits the LED array corresponding to the input image data signal, and irradiates the surface of the photosensitive drum 4 with light. As a result, the LED head 11 forms an electrostatic latent image on the photosensitive drum 4.

  In the example shown in FIG. 1, the printing mechanism Me2 rotates the photosensitive drum 4 in the clockwise direction and the charging roller 3, the developing roller 5, and the supply roller 7 in the counterclockwise direction during printing.

  At this time, in the printing mechanism Me2, the charging roller 3 uniformly charges the surface of the photosensitive drum 4, and then the LED head 11 partially covers the surface of the photosensitive drum 4 according to the image data acquired from the print data. Exposure. As a result, the printing mechanism Me <b> 2 forms an electrostatic latent image on the surface of the photosensitive drum 4. At this time, the supply roller 7 supplies the toner TN to the developing roller 5, the developing blade 6 adjusts the layer thickness of the toner TN adhered to the developing roller 5, and the developing roller 5 The toner TN is supplied to the photosensitive drum 4. Accordingly, the printing mechanism Me2 develops the electrostatic latent image formed on the surface of the photosensitive drum 4 as a toner image.

  The toner image on the photosensitive drum 4 is primarily transferred to the intermediate transfer belt 12 by the primary transfer roller 10 of the transfer mechanism Me3. Thereafter, the neutralizing light source 8 neutralizes the surface of the photosensitive drum 4 by exposing it.

  The printer 1 configured as a tandem intermediate transfer type color printer has four printing mechanisms Me2. The four printing mechanisms Me2 are independent from each other and are arranged side by side on the intermediate transfer belt 12 along the traveling direction of the intermediate transfer belt 12. Each of the four printing mechanisms Me2 uses, for example, toner TN of each color of black (K), yellow (Y), magenta (M), and cyan (C) to transfer a toner image corresponding to each color to a photosensitive drum. 4 is formed.

  The four printing mechanisms Me2 have the same configuration except that the color of the toner TN housed in the toner cartridge 9 is different. Hereinafter, when distinguishing components corresponding to each color of black (K), yellow (Y), magenta (M), and cyan (C), an alphabetic character is added at the end of the code given to each component. The description will be given with any one of “(K)”, “(Y)”, “(M)”, and “(C)”.

  The transfer mechanism Me3 is a mechanism that transfers the toner image formed on the photosensitive drum 4 of the printing mechanism Me2 to the paper P. The transfer mechanism Me3 includes a primary transfer roller 10, an intermediate transfer belt 12, a drive roller 13, a secondary transfer roller 22, a secondary transfer counter roller 23, a paper monitoring sensor 24, a cleaning blade 63, and a waste toner tank 64. ing.

  The primary transfer roller 10 is a member that transfers a toner image formed on the photosensitive drum 4 of the printing mechanism Me2 from the photosensitive drum 4 onto the intermediate transfer belt 12. The primary transfer roller 10 rotates with the photosensitive drum 4. The printer 1 has four primary transfer rollers 10 corresponding to the four printing mechanisms Me2. Each primary transfer roller 10 is provided on the inner peripheral side of the intermediate transfer belt 12 and at a position facing each photosensitive drum 4.

  In addition to the primary transfer roller 10, the transfer mechanism Me3 includes a secondary transfer roller 22 as a transfer roller for transferring a toner image. Hereinafter, when the transfer operation by the primary transfer roller 10 and the transfer operation by the secondary transfer roller 22 are distinguished, the transfer operation by the primary transfer roller 10 is referred to as “primary transfer”, and the transfer by the secondary transfer roller 22 is performed. The operation is referred to as “secondary transfer”.

  The intermediate transfer belt 12 is an intermediate transfer medium for finally transferring each toner image formed on the photosensitive drum 4 of the printing mechanism Me2 onto the paper P. The intermediate transfer belt 12 is formed into a seamless endless shape by a high-resistance semiconductive plastic film.

  The intermediate transfer belt 12 is disposed between the photosensitive drum 4 and the primary transfer roller 10, between the secondary transfer roller 22 and the secondary transfer counter roller 23, between the pre-charging brush 34 and the metal plate 35, and cleaning. It is stretched between the brush 36 and the cleaning brush facing roller 37. In addition, the intermediate transfer belt 12 is stretched by a driving roller 13, a secondary transfer counter roller 23, and a cleaning brush counter roller 37 so as to freely run.

The intermediate transfer belt 12 travels in the direction of arrow a as the driving roller 13 is rotationally driven by a belt motor 47 (see FIG. 4). At that time, the toner images formed on the four photosensitive drums 4 are primarily transferred onto the intermediate transfer belt 12 by being superposed on the surface by the primary transfer roller 10. As a result, a color toner image is formed on the intermediate transfer belt 12.
The intermediate transfer belt 12 becomes an image carrier that carries a color toner image, and conveys the color toner image to the secondary transfer roller 22. Thereafter, the color toner image is secondarily transferred from the intermediate transfer belt 12 to the paper P by the secondary transfer roller 22.

  For example, the intermediate transfer belt 12 is pressed against the four photosensitive drums 4 by the four primary transfer rollers 10. Thus, the surface of the intermediate transfer belt 12 is in contact with each photosensitive drum 4, and a transfer nip portion (hereinafter referred to as “primary transfer nip portion”) N <b> 1 is formed between each intermediate drum and each photosensitive drum 4. . The printer 1 applies a predetermined DC voltage for primary transfer (hereinafter, referred to as “primary transfer voltage”) to each transfer roller 10 from a primary transfer voltage generator 57 (see FIG. 4). Accordingly, the printer 1 performs primary transfer by sequentially superimposing the toner images on the photosensitive drums 4 from the photosensitive drums 4 onto the intermediate transfer belt 12.

  The intermediate transfer belt 12 is pressed against the secondary transfer counter roller 23 by the secondary transfer roller 22. Thus, the surface of the intermediate transfer belt 12 is in contact with the secondary transfer roller 22 to form a transfer nip portion (hereinafter referred to as “secondary transfer nip portion”) N2. The printer 1 applies a predetermined DC voltage for secondary transfer (hereinafter referred to as “secondary transfer voltage”) to the secondary transfer roller 22 from the secondary transfer voltage generator 58 (see FIG. 4). As a result, the printer 1 secondarily transfers the toner image on the intermediate transfer belt 12 from the intermediate transfer belt 12 to the paper P.

  The drive roller 13 is a member that causes the intermediate transfer belt 12 to travel. The drive roller 13 is driven and rotated by a belt motor 47 (see FIG. 4), thereby causing the intermediate transfer belt 12 to travel in the direction of arrow a.

  The secondary transfer roller 22 is a member that transfers the toner image on the intermediate transfer belt 12 to the paper P. The secondary transfer roller 22 is provided on the downstream side of the pinch roller 17 and the registration roller 18 and on the outer peripheral side of the intermediate transfer belt 12. The secondary transfer roller 22 is driven and rotated by a secondary transfer motor 49 (see FIG. 4), thereby causing the intermediate transfer belt 12 to travel and conveying the paper P.

  The secondary transfer counter roller 23 is a member that supports the intermediate transfer belt 12 so as to run freely. The secondary transfer counter roller 23 is provided at a position downstream of the pinch roller 17 and registration roller 18 and on the inner peripheral side of the intermediate transfer belt 12 so as to face the secondary transfer roller 22 with the intermediate transfer belt 12 interposed therebetween. It has been. The secondary transfer counter roller 23 rotates with the secondary transfer roller 22.

  The paper monitoring sensor 24 is a sensor for monitoring the winding of the paper P around the secondary transfer roller 22 and the failure of separation of the paper P from the intermediate transfer belt 12. The sheet monitoring sensor 24 is provided on the downstream side of the secondary transfer roller 22.

The cleaning blade 63 is a member that scrapes off the toner TN adhering to the surface of the secondary transfer roller 22 to the waste toner tank 64. The cleaning blade 63 is made of a flexible rubber material or plastic material, and is provided along the axial direction of the secondary transfer roller 22 so that the tip thereof is in parallel with the secondary transfer roller 22. .
The waste toner tank 64 is a storage unit that stores the toner TN scraped off by the cleaning blade 63.

  In the example shown in FIG. 1, in the transfer mechanism Me3, the secondary transfer roller 22 rotates clockwise during printing, and the primary transfer roller 10, the driving roller 13, and the secondary transfer counter roller 23 are counterclockwise. Rotate around.

  At this time, in the transfer mechanism Me3, the four primary transfer rollers 10 corresponding to the respective colors draw the toner images on the corresponding photosensitive drums 4, and the toner images are superimposed on the intermediate transfer belt 12 to perform the primary transfer. To do. Thereafter, in the transfer mechanism Me3, the secondary transfer roller 22 draws the toner image on the intermediate transfer belt 12 and secondarily transfers the toner image onto the paper P.

  For example, the printer 1 configured as a tandem-type intermediate transfer type color printer has toners of each color of black (K), yellow (Y), magenta (M), and cyan (C) based on print data. Using TN, toner images corresponding to the respective colors are formed on the respective photosensitive drums 4 of the four printing mechanisms Me2. Then, the printer 1 performs primary transfer by sequentially superimposing the toner images formed on the four photosensitive drums 4 from the photosensitive drums 4 onto the intermediate transfer belt 12 by the primary transfer roller 10 of the transfer mechanism Me3. To do. As a result, the printer 1 forms a color toner image on the intermediate transfer belt 12. Thereafter, the printer 1 aligns the paper P with the color toner image on the intermediate transfer belt 12, and the secondary transfer roller 22 of the transfer mechanism Me3 transfers the color toner image from the intermediate transfer belt 12 to the paper P. Secondary transfer to.

  The paper P that has passed through the secondary transfer roller 22 is separated from the intermediate transfer belt 12 and conveyed to a guide 19B that guides the paper P to the fixing mechanism Me4.

  By the way, the toner TN partially adheres to the surface of the secondary transfer roller 22 and partially remains on the intermediate transfer belt 12 after the secondary transfer. Therefore, the printer 1 cleans the secondary transfer roller 22 and the intermediate transfer belt 12. Cleaning of the secondary transfer roller 22 is performed by the cleaning blade 63 scraping off the toner TN adhering to the surface of the secondary transfer roller 22 to the waste toner tank 64. The intermediate transfer belt 12 is cleaned by the toner diffusion member 33 diffusing the toner remaining on the intermediate transfer belt 12 (hereinafter referred to as “residual toner RTN”), and then the cleaning mechanism Me5 removing the residual toner RTN. Is done by doing.

  The fixing mechanism Me4 is a mechanism for fixing the toner image transferred to the paper P to the paper P. The fixing mechanism Me4 heats and pressurizes the paper P to melt the toner image transferred to the paper P, thereby fixing the toner image on the paper P. The fixing mechanism Me4 includes a heat roller 26, a pressure roller 27, a heater 28, a thermistor 29, and a discharge sensor 30.

  The heat roller 26 is a member that transfers heat to the paper P. The heat roller 26 is configured to incorporate a heater 28. The heat roller 26 is provided on the downstream side of the secondary transfer counter roller 23. The heat roller 26 is driven by a heat roller motor 50 (see FIG. 4) and rotates to convey the paper P.

  The pressure roller 27 is a member that presses the paper P by pressing the paper P against the heat roller 26. The pressure roller 27 is provided on the downstream side of the secondary transfer roller 22 so as to face the heat roller 26 via the conveyance path 14. The pressure roller 27 is rotated by the heat roller 26.

The heater 28 is a heat source for heating the paper P. The heater 28 is constituted by, for example, a halogen lamp.
The thermistor 29 is a sensor for monitoring the temperature of the heat roller 26.
The discharge sensor 30 is a sensor for monitoring the jam of the paper P and the winding of the paper P around the heat roller 26 in the fixing mechanism Me4.

  The fixing mechanism Me4 heats and presses the paper P while conveying the paper P toward the stacker 31 by the heat roller 26 and the pressure roller 27 during printing, and melts the toner image on the paper P. The toner image is fixed on the paper P. A thermistor 29 is provided near the surface of the heat roller 26. The thermistor 29 monitors the temperature of the heat roller 26. A discharge sensor 30 is provided on the downstream side of the heat roller 26. The discharge sensor 30 monitors jamming of the paper P and winding of the paper P around the heat roller 26 in the fixing mechanism Me4. A guide 19 </ b> C for guiding the paper P to the stacker 31 is provided on the downstream side of the discharge sensor 30. When the toner image is fixed on the paper P, the fixing mechanism Me4 conveys the printed paper P toward the stacker 31 by the heat roller 26 and the pressure roller 27, and discharges the paper P to the stacker 31.

  The cleaning mechanism Me5 is a mechanism for removing the residual toner RTN remaining on the intermediate transfer belt 12 and cleaning the intermediate transfer belt 12 after the secondary transfer. The cleaning mechanism Me5 is provided at a position downstream of the secondary transfer roller 22 and the secondary transfer counter roller 23 and upstream of the printing mechanism Me2 (K). The cleaning mechanism Me5 includes a pre-charging brush 34, a metal plate 35, a cleaning brush 36, a cleaning brush facing roller 37, a collection roller 38, a cleaning blade 39, and a waste toner tank 40.

  The pre-charging brush 34 is a member that aligns the charging polarity of the toner TN remaining on the intermediate transfer belt 12 to an arbitrary polarity. The pre-charging brush 34 includes a brush portion 34a that is a contact portion with the intermediate transfer belt 12, and a brush holding portion 34b that holds the brush portion 34a. In addition, the brush part 34a is comprised by the brush shape with the electroconductive member. The pre-charging brush 34 is in the state where the brush part 34a is in the middle while a predetermined DC voltage for pre-charging (hereinafter referred to as “pre-charging voltage”) is applied from the pre-charging voltage generator 59 (see FIG. 4). By contacting the transfer belt 12, the charging polarity of the residual toner RTN on the intermediate transfer belt 12 is made to be an arbitrary polarity.

  The metal plate 35 is a member that supports the intermediate transfer belt 12 so as to run freely. The metal plate 35 is provided so as to face the pre-charging brush 34 with the intermediate transfer belt 12 interposed therebetween, and is connected to the ground.

  The cleaning brush 36 is a member that cleans the intermediate transfer belt 12. The cleaning brush 36 has a roller-like configuration in which a brush cloth 36b is spirally wound around a metal core 36a. The cleaning brush 36 is provided to face the cleaning brush facing roller 37 through the intermediate transfer belt 12 so as to push the intermediate transfer belt 12 into the cleaning brush facing roller 37 by a predetermined amount.

  The cleaning brush 36 is driven in a direction opposite to the traveling direction of the intermediate transfer belt 12 by a brush motor 51 (see FIG. 4). Further, the cleaning brush 36 is used for cleaning the intermediate transfer belt 12 from the cleaning voltage generator 60 (see FIG. 4). A predetermined DC voltage (hereinafter referred to as “cleaning voltage”) is applied, and the residual toner RTN is removed from the intermediate transfer belt 12 by mechanical and electrical forces. Hereinafter, the residual toner RTN removed from the intermediate transfer belt 12 is referred to as “removed toner rtn (not shown)”.

  The cleaning brush facing roller 37 is a member that supports the intermediate transfer belt 12 so as to run freely. The cleaning brush facing roller 37 is provided to face the cleaning brush 36 with the intermediate transfer belt 12 interposed therebetween.

  The collection roller 38 is a member that collects the removed toner rtn that has been removed from the intermediate transfer belt 12 by the cleaning brush 36 and adhered to the cleaning brush 36. The collection roller 38 is provided in a state where it is pushed into the cleaning brush 36 by a predetermined amount. The collection roller 38 is driven in the same direction as the rotation direction of the cleaning brush 36 by the collection motor 52 (see FIG. 4), and further, a predetermined voltage for collecting the removed toner rtn is collected from the collection voltage generator 61 (see FIG. 4). A DC voltage (hereinafter referred to as “collection voltage”) is applied, and the removed toner rtn is collected from the cleaning brush 36 by an electric force.

The cleaning blade 39 is a member that scrapes off the removed toner rtn adhering to the recovery roller 38 to the waste toner tank 40. The cleaning blade 39 is made of a flexible rubber material or plastic material, and is provided along the axial direction of the collection roller 38 so that the tip thereof is in parallel with the collection roller 38.
The waste toner tank 40 is a storage unit that stores the removed toner rtn scraped off by the cleaning blade 39.

  In the example shown in FIG. 1, in the cleaning mechanism Me5, the cleaning brush 36, the cleaning brush facing roller 37, and the recovery roller 38 all rotate counterclockwise during printing.

  At this time, the cleaning mechanism Me5 is in contact with the intermediate transfer belt 12 during printing in a state where the brush portion 34a of the pre-charging brush 34 is applied with the pre-charging voltage from the pre-charging voltage generator 59 (see FIG. 4). As a result, the charging polarity of the residual toner RTN on the intermediate transfer belt 12 is set to an arbitrary polarity. Then, the brush cloth 36b of the cleaning brush 36 comes into contact with the intermediate transfer belt 12 in a state where the cleaning voltage is applied from the cleaning voltage generator 60 (see FIG. 4). Residual toner RTN is removed from the transfer belt 12. Thereafter, when the recovery roller 38 is in contact with the cleaning brush 36 in a state where the recovery voltage is applied from the recovery voltage generator 61 (see FIG. 4), the removal toner rtn is removed from the cleaning brush 36 by electric force. to recover. Then, the cleaning blade 39 scrapes the removed toner rtn from the collection roller 38 into the waste toner tank 40.

  As shown in FIG. 1, the printer 1 having such a configuration includes a toner diffusion member 33 that is a characteristic member of the present invention between the secondary transfer roller 22 and the cleaning mechanism Me5. The toner diffusion member 33 is a member that diffuses the residual toner RTN on the intermediate transfer belt 12.

  The toner diffusion member 33 is formed in a long bar shape. The toner diffusing member 33 includes a brush portion 33a that is a contact portion with the intermediate transfer belt 12 and a brush holding portion 33b that holds the brush portion 33a on the surface facing the conveyance surface of the intermediate transfer belt 12. ing. The tip portion of the brush portion 33a is formed in a substantially flat shape, and constitutes a contact surface S1 (see FIG. 2) that contacts the transport surface of the intermediate transfer belt 12 in parallel. The contact surface S <b> 1 is provided to extend in a direction that is inclined and intersects with the traveling (conveying) direction of the intermediate transfer belt 12. Here, the description will be made assuming that the contact portion with the intermediate transfer belt 12 is constituted by a brush-like member. However, the contact portion with the intermediate transfer belt 12 is not limited to this, for example, felt. It may be configured by a cloth such as.

  The toner diffusion member 33 is disposed at a position upstream of the cleaning brush 36 (see FIG. 1). The toner diffusing member 33 is inclined with respect to the traveling (conveying) direction of the intermediate transfer belt 12 such that the central portion in the longitudinal direction is the upstream side and the end portion in the longitudinal direction is the downstream side.

  For example, in the example shown in FIG. 2, the two toner diffusing members 33 are divided and provided on the left and right end portions with respect to the center in the transport direction of the intermediate transfer belt 12. Hereinafter, when the toner diffusion member 33 provided on the right side is distinguished from the toner diffusion member 33 provided on the left side, the toner diffusion member 33 provided on the right side is referred to as “toner diffusion member 33R” and provided on the left side. The toner diffusion member 33 thus obtained is referred to as “toner diffusion member 33L”. In the example shown in FIG. 2, the longitudinal direction of the intermediate transfer belt 12 (intermediate transfer belt 12) is such that the toner diffusion member 33 </ b> R and the toner diffusion member 33 </ b> L having a length L open from the upstream side toward the downstream side. With respect to the traveling direction) with an acute inclination angle θ1 and symmetrically inclined. Note that the toner diffusing member 33R and the toner diffusing member 33L have an obtuse inclination angle θ2 with respect to the traveling (conveying) direction of the intermediate transfer belt 12, and the left and right They are provided symmetrically. Here, the inclination angle θ2 has a relationship of “inclination angle θ1 + 90 °”.

  The length L of the toner diffusing member 33, the inclination angles θ1 and θ2, and the attachment position on the intermediate transfer belt 12 are the minimum paper width Lmin of the paper P that can be printed by the printer 1 and the printing speed of the printer 1. Determined based on V.

  Further, the toner diffusing member 33 is not limited to the configuration shown in FIG. 2 but can be modified to various configurations. An example of the configuration is shown in FIG. In the example shown in FIG. 3A, the toner diffusing member 33 has two toner diffusing members 33R and two toner diffusing members 33L. Note that the numbers of the toner diffusing member 33R and the toner diffusing member 33L can be arbitrarily changed, and can be different from each other. In the example shown in FIG. 3B, the toner diffusing member 33 has a configuration in which the toner diffusing member 33R is formed longer than the toner diffusing member 33L and is alternately overlapped in the transport direction. The toner diffusing member 33 may be configured by connecting the toner diffusing member 33R and the toner diffusing member 33L as one member.

(Configuration of control system of image forming apparatus)
Next, the configuration of the control system of the printer 1 will be described with reference to FIG.
The printer 1 includes a host interface unit 41, a command / image processing unit 42, an LED head interface unit 43, a mechanism control unit 44, a high voltage control unit 53, a charging voltage generation unit 54, a supply voltage generation unit 55, a development voltage generation unit 56, A primary transfer voltage generator 57, a secondary transfer voltage generator 58, a pre-charge voltage generator 59, a cleaning voltage generator 60, and a recovery voltage generator 61 are included.

  The host interface unit 41 is a functional unit that serves as a physical layer interface with a host device such as a host computer (not shown). The host interface unit 41 includes a connector and a communication chip.

  The command / image processing unit 42 is a functional unit that controls the operation of the entire printer 1. The command / image processing unit 42 performs processing for interpreting commands and print data transmitted from the host device, processing for developing image data based on the print data into bitmap memory as bitmap data, and the like. The command / image processing unit 42 includes a microprocessor, a RAM, special hardware for developing image data, and the like.

  The LED head interface unit 43 is a functional unit that controls light emission of the LED head 11. The LED head interface unit 43 converts the bitmap data developed in the bitmap memory by the command / image processing unit 42 to the interfaces of the LED heads 11 (K), 11 (Y), 11 (M), and 11 (C) for each color. The data is processed according to the above, and the light emission of the LED head 11 is controlled. The LED head interface unit 43 includes a semi-custom LSI and a RAM.

  The mechanism control unit 44 is a functional unit that controls the operation of the main part of the printer 1. The mechanism control unit 44 controls the operation of the components of the printing system (specifically, referring to the state of the output signal output from each sensor 21, 24, 30 in accordance with an instruction from the command / image processing unit 42. Is a high-voltage power supply unit (specifically, a charging voltage generation unit 54, a supply voltage generation) via a drive control of each motor (circuit) 45 to 52, a temperature control of the heater 28, etc.) and a high-voltage control unit 53. 55, development voltage generator 56, primary transfer voltage generator 57, secondary transfer voltage generator 58, precharge voltage generator 59, cleaning voltage generator 60, and recovery voltage generator 61). I do. The mechanism control unit 44 includes a microprocessor and a RAM.

  Each motor (circuit) 45 to 52 includes various motors for moving each printing mechanism Me2, the secondary transfer roller 22, the heat roller 26, and the like, and a driver for driving the motors. Here, the heater 28 is configured by a halogen lamp and is provided in the heat roller 26. The mechanism controller 44 controls the temperature of the heater 28 based on the output signal of the thermistor 29 provided near the surface of the heat roller 26.

  The high voltage control unit 53 includes a high voltage power supply unit (specifically, a charging voltage generation unit 54, a supply voltage generation unit 55, a development voltage generation unit 56, a primary transfer voltage generation unit 57, a secondary transfer voltage generation unit 58, This is a functional means for controlling the operation of the charging voltage generator 59, the cleaning voltage generator 60, and the recovery voltage generator 61). The high voltage control unit 53 controls the operation of the high voltage power supply unit in accordance with an instruction from the mechanism control unit 44. The high voltage control unit 53 is configured by a microprocessor, a custom LSI, or the like.

The charging voltage generator 54 applies predetermined DC for charging the photosensitive drum 4 to be applied to the charging rollers 3 (K), 3 (Y), 3 (M), and 3 (C) in accordance with an instruction from the high voltage controller 53. A high-voltage power supply unit that generates and stops a voltage (hereinafter referred to as “charging voltage”).
The supply voltage generator 55 supplies toner TN to the developing roller 5 that is applied to the supply rollers 7 (K), 7 (Y), 7 (M), and 7 (C) in accordance with instructions from the high voltage controller 53. The high-voltage power supply unit generates and stops a predetermined DC voltage (hereinafter referred to as “supply voltage”).
The developing voltage generator 56 applies a predetermined voltage for developing the electrostatic latent image to be applied to the developing rollers 5 (K), 5 (Y), 5 (M), and 5 (C) in accordance with an instruction from the high voltage controller 53. A high-voltage power supply unit that generates and stops a DC voltage (hereinafter referred to as “development voltage”).

The primary transfer voltage generation unit 57 is used for primary transfer of the toner TN to be applied to the transfer rollers 10 (K), 10 (Y), 10 (M), and 10 (C) in accordance with an instruction from the high voltage control unit 53. A high-voltage power supply unit that generates and stops a predetermined DC voltage (hereinafter referred to as “primary transfer voltage”).
The secondary transfer voltage generator 58 applies a predetermined DC voltage (hereinafter referred to as “secondary transfer voltage”) for secondary transfer of the toner TN to be applied to the secondary transfer roller 22 in accordance with an instruction from the high voltage controller 53. It is a high-voltage power supply unit that generates and stops.

The pre-charging voltage generator 59 generates a predetermined DC voltage (hereinafter referred to as “pre-charging voltage”) for precharging the residual toner RTN to be applied to the pre-charging brush 34 in accordance with an instruction from the high-voltage controller 53. And a high voltage power supply unit for stopping.
The cleaning voltage generator 60 generates and stops a predetermined DC voltage for cleaning the intermediate transfer belt 12 (hereinafter referred to as “cleaning voltage”) to be applied to the cleaning brush 36 in accordance with an instruction from the high voltage controller 53. A high-voltage power supply unit.
The recovery voltage generator 61 generates and stops a predetermined DC voltage (hereinafter referred to as “recovery voltage”) for recovering the removed toner rtn to be applied to the recovery roller 38 in accordance with an instruction from the high voltage controller 53. It is a power supply part.

<Operation of Image Forming Apparatus>
Hereinafter, the operation of the printer 1 during printing will be described with reference to FIGS. FIG. 5 is a distribution diagram showing the remaining state of the residual developer during borderless printing. FIGS. 6 and 7 are diagrams showing the relationship between the length of the residual developer and the cleaning efficiency, respectively. 6 and 7 show the relationship between the toner length of the residual toner RTN entering the same location in the longitudinal direction of the cleaning brush 36 and the cleaning efficiency of the cleaning brush 36, respectively. FIG. 8 is a distribution diagram showing a diffusion state of the residual developer of the image forming apparatus according to the first embodiment.

When the printer 1 receives print data from the host device, the printer 1 forms a toner image as follows.
First, in the printer 1, the command / image processing unit 42 outputs a warm-up start instruction for the fixing mechanism Me 4 to the mechanism control unit 44, and performs image data expansion processing based on the print data. Bitmap data is generated for each color.

  Here, when a warm-up start instruction is input from the command / image processing unit 42 to the mechanism control unit 44, the mechanism control unit 44 refers to the state of the output signal output from the thermistor 29 while referring to the heat roller 26. Is adjusted to ON / OFF of the heater 28 so that the temperature of the heat roller 26 is adjusted. The “fixing temperature” means a temperature at which the toner image on the paper P can be fixed on the paper P. When the temperature of the heat roller 26 reaches a predetermined fixing temperature, the printer 1 starts a printing operation.

  Next, the mechanism control unit 44 controls the driving of the belt motor 47, the drum motor 48, the secondary transfer motor 49, the brush motor 51, and the collection motor 52 to drive the drive roller 13 and each printing mechanism Me2 (K). , Me2 (Y), Me2 (M), Me2 (C), the secondary transfer roller 22, the cleaning brush 36, and the recovery roller 38 are driven.

  At the same time, the mechanism control unit 44 outputs a voltage generation instruction to the high voltage control unit 53. In response to this, the high voltage control unit 53 causes the charging voltage generation unit 54, the supply voltage generation unit 55, and the development voltage generation unit 56 to apply voltages to the corresponding components.

  As a result, the charging voltage generator 54 applies preset charging voltages to the charging rollers 3 of the four printing mechanisms Me2 (K), Me2 (Y), Me2 (M), and Me2 (C). The supply voltage generator 55 applies a preset supply voltage to the supply rollers 7 of the four printing mechanisms Me2 (K), Me2 (Y), Me2 (M), and Me2 (C). Similarly, the development voltage generator 56 applies a preset development voltage to the development rollers 5 of the four printing mechanisms Me2 (K), Me2 (Y), Me2 (M), and Me2 (C).

  Here, the toner image forming operation of the printing mechanism Me2 will be described using the black (K) printing mechanism Me2 (K). The operations of the yellow (Y), magenta (M), and cyan (C) printing mechanisms Me2 (Y), Me2 (M), and Me2 (C) are the same as those of the printing mechanism Me2 (K). Therefore, here, a duplicate description is omitted.

  For example, the charging voltage generator 54 applies a charging voltage of about −1100 V to the charging roller 3 (K). As a result, the charging roller 3 (K) uniformly charges the surface of the photosensitive drum 4 (K) to about −600V.

  The supply voltage generator 55 applies a supply voltage of about −250 V to the supply roller 7 (K), for example, and the development voltage generator 56 applies a development voltage of about −200 V, for example, to the development roller 5 ( K). As a result, an electric field in the direction from the developing roller 5 (K) toward the supply roller 7 (K) is formed in the vicinity of the nip portion between the developing roller 5 (K) and the supply roller 7 (K).

  The toner cartridge 9 (K) of the printing mechanism Me2 (K) contains black (K) toner TN. The toner cartridge 9 (K) supplies the toner TN to the supply roller 7 (K). The toner TN supplied to the supply roller 7 (K) is strongly rubbed by the developing roller 5 (K) and the supply roller 7 (K). As a result, the toner TN is frictionally charged. In the first embodiment, the toner TN includes developing rollers 5 (K), 5 (Y), 5 (M), and 5 (C), and supply rollers 7 (K), 7 (Y), and 7 (M). , 7 (C), the battery is negatively charged.

  The negatively charged toner TN adheres to the surface of the developing roller 5 (K) by the Coulomb force received from the electric field directed from the developing roller 5 (K) toward the supply roller 7 (K).

  The developing roller 5 (K) rotates to convey the toner TN attached to the surface to a contact portion between the developing roller 5 (K) and the developing blade 6 (K). The developing blade 6 (K) adjusts the toner TN attached to the surface of the developing roller 5 (K) to a constant layer thickness. As a result, a toner layer having a uniform thickness is formed on the developing roller 5 (K). Thereafter, the developing roller 5 (K) further rotates to convey the toner TN adhered to the surface to the nip portion between the developing roller 5 (K) and the photosensitive drum 4 (K).

  On the other hand, the command / image processing unit 42 outputs bitmap data for each page to the LED head interface unit 43. The LED head interface unit 43 causes the LED of the LED head 11 (K) to blink corresponding to the bitmap data, and partially exposes the surface of the photosensitive drum 4 (K). As a result, the surface of the photosensitive drum 4 (K) is partially neutralized to about −50V. As a result, the surface of the photosensitive drum 4 (K) is in a state where an exposed portion (hereinafter referred to as “exposed portion”) is neutralized to about −50 V, and a portion that is not exposed (hereinafter referred to as “non-exposed portion”). Will be charged to about -600V. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 4 (K).

  The photosensitive drum 4 (K) rotates to convey the electrostatic latent image formed on the surface to the nip portion between the photosensitive drum 4 (K) and the developing roller 5 (K). In the nip portion, electric fields having different directions are formed. For example, in the exposure portion on the photosensitive drum 4 (K), since the exposure portion is neutralized to about −50 V, an electric field in the direction from the photosensitive drum 4 (K) toward the developing roller 5 (K) is formed. On the contrary, in the non-exposed portion on the photosensitive drum 4 (K), the non-exposed portion is not neutralized and is charged to about −600 V, so the direction from the developing roller 5 (K) toward the photosensitive drum 4 (K). Is formed. The toner TN on the developing roller 5 (K) is selectively only from the toner layer on the developing roller 5 (K) to the exposed portion on the photosensitive drum 4 (K) because the toner TN is negatively charged. Adhere to. As a result, the electrostatic latent image on the photosensitive drum 4 (K) is developed as a toner image.

Next, the printer 1 performs a primary transfer operation and a secondary transfer operation as follows.
As described above, the intermediate transfer belt 12 has four photosensitive drums 4 (K), 4 (Y), and four primary transfer rollers 10 (K), 10 (Y), 10 (M), and 10 (C). 4 (M) and 4 (C). Thereby, the surface of the intermediate transfer belt 12 is in contact with the photosensitive drums 4 (K), 4 (Y), 4 (M), 4 (C), and the photosensitive drums 4 (K), 4 (Y). , 4 (M), 4 (C), a primary transfer nip portion N1 (see FIG. 1) is formed.

  The mechanism control unit 44 transfers the toner images formed on the four photosensitive drums 4 (K), 4 (Y), 4 (M), and 4 (C) to the primary transfer nip portion N1 (see FIG. 1). An instruction to generate a primary transfer voltage is output to the high-voltage control unit 53 in accordance with the sequential arrival timing. In response to this, the high voltage controller 53 applies a primary transfer voltage to the transfer rollers 10 (K), 10 (Y), 10 (M), and 10 (C) to the primary transfer voltage generator 57. Let As a result, the primary transfer voltage generator 57 applies a predetermined primary transfer voltage to each of the transfer rollers 10 (K), 10 (Y), 10 (M), and 10 (C).

  In the first embodiment, it is assumed that the primary transfer voltage value is about + 2000V, for example. At this time, at the primary transfer nip portion N1, the transfer rollers 10 (K), 10 (Y), 10 (M), 10 (C) to the photosensitive drums 4 (K), 4 (Y), 4 (M ), 4 (C). Since the toner images formed on the photosensitive drums 4 (K), 4 (Y), 4 (M), and 4 (C) are charged with negative polarity, the photosensitive drums 4 (K) and 4 (K) Y), 4 (M), and 4 (C) are overlaid on the intermediate transfer belt 12 and primarily transferred. As a result, a color toner image is formed on the intermediate transfer belt 12.

  The mechanism control unit 44 drives the hopping motor 45 to rotate the hopping roller 16 before the toner image primarily transferred onto the intermediate transfer belt 12 reaches the secondary transfer nip N2 (see FIG. 1). Let Accordingly, the hopping roller 16 feeds one sheet P from the sheet storage cassette 15 between the pinch roller 17 and the registration roller 18.

  The mechanism control unit 44 monitors the output signal of the paper feed sensor 21 and stops driving the hopping motor 45 when detecting that the leading edge of the paper P has reached between the pinch roller 17 and the registration roller 18.

  Next, the mechanism control unit 44 drives the registration motor 46 in accordance with the timing at which the toner image primarily transferred onto the intermediate transfer belt 12 reaches the secondary transfer nip N2 (see FIG. 1). The paper P between the pinch roller 17 and the registration roller 18 is conveyed to the guide 19A. As a result, the sheet P is guided by the guide 19A and reaches the secondary transfer nip portion N2.

  In addition, the mechanism control unit 44 gives an instruction to generate a secondary transfer voltage in accordance with the timing at which the toner image primarily transferred onto the intermediate transfer belt 12 reaches the secondary transfer nip N2, and the high voltage control unit 53 Output to. In response to this, the high-voltage controller 53 causes the secondary transfer voltage generator 58 to apply the secondary transfer voltage to the secondary transfer roller 22. As a result, the secondary transfer voltage generator 58 applies a predetermined secondary transfer voltage to the secondary transfer roller 22.

  In this embodiment, it is assumed that the secondary transfer voltage is about + 2000V, for example. At this time, an electric field in the direction from the secondary transfer roller 22 to the secondary transfer counter roller 23 is formed in the secondary transfer nip portion N2. Since the toner image primarily transferred onto the intermediate transfer belt 12 is negatively charged, it is secondarily transferred from the intermediate transfer belt 12 onto the paper P. At this time, in the case of borderless printing, the toner TN adheres to the secondary transfer roller 22, but the toner TN attached to the secondary transfer roller 22 is scraped off to the waste toner tank 64 by the cleaning blade 63. It is.

  The sheet P on which the toner image is transferred is separated from the intermediate transfer belt 12, guided by the guide 19B, and conveyed to the fixing mechanism Me4. In the fixing mechanism Me4, the heat roller 26 has already reached the fixable temperature. When the paper P reaches the fixing mechanism Me4, the heat roller 26 and the pressure roller 27 sandwich and convey the paper P. As a result, the heat roller 26 and the pressure roller 27 heat and press the paper P to melt the toner image on the paper P. As a result, the toner image is fixed on the paper P.

  The paper P on which the toner image is fixed is guided by the guide 19C and discharged to the stacker 31. The printer 1 runs the intermediate transfer belt 12 in parallel with the fixing process of the toner image onto the paper P. As a result, the residual toner RTN on the intermediate transfer belt 12 passes through the position where the toner diffusion member 33 is disposed and is conveyed to the cleaning mechanism Me5.

  At this time, the toner diffusion member 33 diffuses the residual toner RTN on the intermediate transfer belt 12. The residual toner RTN is generated in a large amount only for borderless printing for the following reason.

  That is, it is preferable that the borderless printing originally forms a toner image having the same size as the size of the paper P and transfers the toner image to the paper P. However, it is difficult for the printer 1 to transfer a toner image having the same size as the size of the paper P in accordance with a predetermined position on the paper P in terms of mechanism and control.

  Therefore, the printer 1 performs borderless printing by forming a toner image larger than the size of the paper P and transferring the toner image to the paper P.

  However, the toner TN remains on the intermediate transfer belt 12 as the residual toner RTN even after the toner image is transferred to the paper P. At this time, as shown in FIG. 5, the residual toner RTN has a sheet on the intermediate transfer belt 12 that is located on the inner side of the size of the sheet P on the intermediate transfer belt 12 (hereinafter referred to as “within the sheet range”). A large amount remains in an area outside the size of P (hereinafter referred to as “out of paper range”). FIG. 5 shows the distribution of residual toner RTN when borderless printing is performed.

  For example, the printer 1 determines the size of the toner image in the vertical and horizontal directions from the size of the paper P with the horizontal width and the vertical width W1 and W2, respectively, from the relationship of accuracy of alignment between the toner image and the paper P. The size (for example, 10 mm in the vertical and horizontal directions) is increased.

  Most of the toner TN constituting the toner image formed in the sheet range is transferred to the sheet P. Therefore, the residual toner RTN within the paper range (hereinafter referred to as “paper residual toner RTNin”) has a very small amount of toner.

  On the other hand, all of the toner TN constituting the toner image formed outside the sheet range is not transferred to the sheet P. Therefore, the residual toner RTN outside the sheet range (hereinafter referred to as “outside sheet residual toner RTNout”) has a very large amount of toner.

  Accordingly, the residual toner RTN is formed in a rectangular shape on the paper P. Therefore, as the residual toner RTNout outside the paper range, as shown in the areas A to D shown in FIG. A large amount remains on the ring.

  Therefore, the printer 1 causes the intermediate transfer belt 12 to travel and convey the residual toner RTN on the intermediate transfer belt 12 in the direction of the cleaning brush 36 (see FIG. 1). Then, the printer 1 brings the cleaning brush 36 into contact with the residual toner RTN. At this time, the cleaning brush 36 removes the residual toner RTN from the intermediate transfer belt 12 and cleans the intermediate transfer belt 12.

  At this time, since the residual toner RTNout outside the paper area on the areas A and B is successively conveyed toward the cleaning brush 36, the cleaning brush 36 contacts the residual toner RTN for a long time at the same location. When the cleaning brush 36 is in contact with the residual toner RTN at the same location for a long time, the cleaning efficiency decreases. This is configured such that the printer 1 collects the removed toner rtn (not shown) removed from the intermediate transfer belt 12 by the cleaning brush 36 from the cleaning brush 36 by the collection roller 38 as the collected toner. The collection roller 38 cannot collect the removed toner rtn from the cleaning brush 36, and the removed toner rtn accumulates in the cleaning brush 36. As a result, the cleaning brush 36 removes the residual toner RTN on the intermediate transfer belt 12. It is because it becomes impossible. Therefore, the cleaning brush 36 may not be able to remove the residual toner RTN from the intermediate transfer belt 12 satisfactorily. If the cleaning brush 36 cannot remove the residual toner RTN from the intermediate transfer belt 12 satisfactorily, the printing quality is naturally deteriorated.

  FIG. 6 shows the relationship between the toner length of the residual toner RTN entering the same position in the longitudinal direction of the cleaning brush 36 and the cleaning efficiency of the cleaning brush 36 when borderless full-surface printing is performed at a predetermined printing density A. FIG. The “toner length of the residual toner RTN entering the same location” means the length of the residual toner RTNout outside the paper range remaining along the transport direction of the intermediate transfer belt 12, and specifically, This means the length of the residual toner RTNout outside the paper range on the area A and the area B.

  In the first exemplary embodiment, it is assumed that the amount of toner per unit area that adheres to the intermediate transfer belt 12 during printing at a printing density A is the maximum amount. Accordingly, the “Δ” mark shown in FIG. 6 indicates the toner length of the residual toner RTN and the cleaning brush when printing is performed at the print density A at which the toner amount per unit area adhering to the intermediate transfer belt 12 is maximum. The relationship with the cleaning efficiency of 36 is shown.

In the first embodiment, the print density is defined by the toner amount. The print density A is the density when the residual toner RTN is the maximum amount. The residual toner RTN becomes the maximum amount when three colors of yellow (Y), magenta (M), and cyan (C) are overlapped. Therefore, in the printer 1 according to the first embodiment, when the toner amount per unit area is 0.50 mg / cm ² for each color, the print density A is the residual toner RTN (0.50 × 3) = 1.50 mg / cm ² .

  As indicated by “Δ” in FIG. 6, when printing is performed at a print density A, the cleaning efficiency of the cleaning brush 36 decreases as the toner length of the residual toner RTN entering the same location becomes longer. This is because the collection roller 38 (see FIG. 1) cannot collect the removed toner rtn from the cleaning brush 36, and the removed toner rtn accumulates on the cleaning brush 36. As a result, the cleaning brush 36 is placed on the intermediate transfer belt 12. This is because the residual toner RTN cannot be removed. As a result of experiments, it has been found that when the cleaning efficiency is 95% or less, it becomes a level at which a cleaning defect can be recognized on the toner image.

  Therefore, when printing is performed at the printing density A, the cleaning brush 36 remains in parallel with the transport direction of the intermediate transfer belt 12 like the out-of-paper residual toner RTNout on the areas A and B. If it is in contact with the toner RTN for a long time, the cleaning efficiency is lowered.

  Here, FIG. 7 shows the relationship between the toner length of the residual toner RTN that enters the same position in the longitudinal direction of the cleaning brush 36 and the cleaning efficiency of the cleaning brush 36 when full border printing is performed at a predetermined printing density B. Show the relationship.

  In the first exemplary embodiment, the amount of toner per unit area that adheres to the intermediate transfer belt 12 when printing at the printing density B is used as the amount of toner per unit area that adheres to the intermediate transfer belt 12 when printing at the printing density A. The amount is ½ of the (maximum amount). Therefore, the mark “◯” shown in FIG. 7 indicates the residual toner RTN when printing is performed at a printing density B where the amount of toner per unit area attached to the intermediate transfer belt 12 is ½ of the maximum amount. The relationship between the toner length and the cleaning efficiency of the cleaning brush 36 is shown. The “Δ” mark shown in FIG. 7 is the same as the “Δ” mark shown in FIG. 6 between the toner length of the residual toner RTN and the cleaning efficiency of the cleaning brush 36 when printing is performed at the print density A. Showing the relationship.

Note that the printing density B is a density when the residual toner RTN is ½ the printing density A. Therefore, for each color, when the toner amount per unit area is 0.50 mg / cm ² , the printing density B is (1.50 / 2) = 0.75 mg / cm ² for the residual toner RTN.

  As indicated by a mark “◯” in FIG. 7, when printing is performed at a print density B, the cleaning brush 36 performs cleaning when the toner amount of the residual toner RTN entering the same location is ½ of the maximum amount. It can be seen that the reduction in efficiency can be greatly reduced.

  In addition, like the out-of-paper residual toner RTNout on the regions C and D, the out-of-paper residual toner RTNout in the direction perpendicular to the conveyance direction of the intermediate transfer belt 12 is the same in the longitudinal direction with respect to the cleaning brush 36. Enter the point. The toner length is about 0 to 20 mm. Therefore, as can be seen from FIGS. 6 and 7, the cleaning brush 36 can satisfactorily remove the out-of-paper area residual toner RTNout on the regions C and D.

  From the above viewpoint, in the first embodiment, the toner diffusing member 33 is provided in the printer 1 in order to reduce the residual toner RTN that enters the same position in the longitudinal direction of the cleaning brush 36.

  FIG. 8 is a diagram showing a diffusion state of the external residual toner RTN entering the same position in the longitudinal direction of the cleaning brush 36 by the toner diffusing member 33. As shown in FIG. 8, the toner diffusing member 33 contacts the out-of-paper area residual toner RTNout that enters the same location in the longitudinal direction of the cleaning brush 36, and the out-of-paper area residual toner RTNout follows the toner flows Fa and Fb. Diffuse. As a result, the residual toner RTNout outside the sheet range becomes the diffusion residual toner RTNd in which the toner amount per unit area is reduced. Therefore, the toner diffusing member 33 can diffuse out-of-paper residual toner RTNout entering the same position in the longitudinal direction of the cleaning brush 36, for example, to about ½ of the maximum amount.

  In the first embodiment, for example, it is assumed that the pre-charging voltage, the cleaning voltage, and the recovery voltage are about −1200 V, about +800 V, and about +1200 V, respectively. In the first embodiment, the toner TN is charged to a negative polarity by the printing mechanism Me2. However, the residual toner RTN on the intermediate transfer belt 12 includes a large amount of residual toner RTN charged to a positive polarity due to the influence of the electric field of the secondary transfer nip portion N2 (see FIG. 1).

  For this reason, the mechanism control unit 44 uses the pre-charging brush 34 to adjust the charging polarity of the residual toner RTN on the intermediate transfer belt 12 to a negative polarity, and rotates the cleaning brush 36 that rotates in the direction opposite to the conveyance direction of the intermediate transfer belt 12. Residual toner RTN is removed from the intermediate transfer belt 12 by mechanical and electrical forces. At this time, the residual toner RTN removed from the intermediate transfer belt 12 adheres to the cleaning brush 36 as removed toner rtn.

  Therefore, the mechanism control unit 44 collects the removed toner rtn from the cleaning brush 36 by the electric force of the collection roller 38. The toner TN collected from the cleaning brush 36 by the collecting roller 38 is scraped off to the waste toner tank 40 by the cleaning blade 39.

  When all the processes are completed, the mechanism control unit 44 stops the belt motor 47, the drum motor 48, the secondary transfer motor 49, the brush motor 51, and the recovery motor 52, and at the same time, gives an instruction to stop the voltage application to a high voltage. Output to the controller 53. In response to this, the high-voltage control unit 53 causes the charging voltage generation unit 54, the development voltage generation unit 56, and the supply voltage generation unit 55 to stop applying voltages to the corresponding components.

  As a result, the precharge voltage generator 59 stops applying the precharge voltage to the precharge brush 34. Further, the cleaning voltage generator 60 stops applying the cleaning voltage to the cleaning brush 36. Further, the recovery voltage generator 61 stops applying the recovery voltage to the recovery roller 38. Thereby, the printer 1 completes the printing operation.

  As described above, the printer 1 has the toner diffusion member 33, and the toner diffusion member 33 causes the intermediate transfer belt 12 to remain in the conveyance direction that remains on the intermediate transfer belt 12 when borderless printing is performed. On the other hand, only the residual toner RTNout outside the sheet range in the parallel direction can be diffused. For this reason, the printer 1 reduces the load on driving the intermediate transfer belt 12 and reduces the wear due to the rubbing against the intermediate transfer belt 12, and the paper remaining on the intermediate transfer belt 12 when performing borderless printing. The out-of-range residual toner RTNout can be diffused before reaching the cleaning mechanism Me5. Therefore, the printer 1 can prevent the residual toner RTN from remaining in a large amount at the same location on the intermediate transfer belt 12. Therefore, the printer 1 can avoid the cleaning brush 36 from coming into contact with the residual toner RTN at the same place for a long time, and thereby, it is possible to suppress a reduction in the cleaning efficiency of the cleaning brush 36. As a result, the printer 1 can satisfactorily clean the out-of-paper residual toner RTNout for a long period of time.

  As described above, according to the printer 1 according to the first embodiment, the developer remaining outside the paper range on the member to be cleaned (intermediate transfer belt 12) (residual toner RTNout outside the paper range) is cleaned well. be able to.

[Embodiment 2]
Hereinafter, the configuration of the image forming apparatus according to the second embodiment will be described with reference to FIGS. 9 and 10. FIG. 9 is a diagram illustrating a configuration of a mechanical system of the image forming apparatus according to the second embodiment. FIG. 10 is a diagram illustrating a configuration of a control system of the image forming apparatus according to the second embodiment.

  Compared with the printer 1 according to the first embodiment, the printer 1B as the image forming apparatus according to the second embodiment has (1) a toner detection sensor 65 (see FIG. 9), and (2) Instead of the mechanism control unit 44 (see FIG. 4), a difference is that a mechanism control unit 66 (see FIG. 10) including a toner detection determination unit 67 and a storage unit 68 is provided. Since the printer 1B has the same configuration as that of the printer 1 according to the first embodiment, the description thereof is omitted here.

  The toner detection sensor 65 is a sensor for detecting the removal result of the residual toner RTN. The toner detection sensor 65 corresponds to a “developer detector” recited in the claims. As shown in FIG. 9, the toner detection sensors 65 are provided at two locations on the downstream side of the cleaning mechanism Me5 and on both ends in the longitudinal direction of the cleaning brush 36 so as to face the intermediate transfer belt 12.

  As shown in FIG. 11, the toner detection sensor 65 is provided so as to be movable in the longitudinal direction of the cleaning brush 36 (longitudinal direction of the toner diffusing member 33). FIG. 11 is a diagram illustrating a moving range of the toner detection sensor used in the second embodiment. The movement range of the toner detection sensor 65 is a detection range of the residual toner RTN removal result. In the second embodiment, the movement range of the toner detection sensor 65 is between the minimum paper width Lmin of the paper P that can be printed by the printer 1B and the maximum paper width Lmax of the paper P that can be printed by the printer 1B. It has become.

  The toner detection sensor 65 is used to measure the intensity of reflected light on the intermediate transfer belt 12 and detect the removal result of the residual toner RTNout outside the sheet range on the intermediate transfer belt 12. FIG. 12 is a schematic diagram illustrating a configuration of a toner detection sensor used in the second embodiment. Here, the toner detection sensor 65 will be described as a reflection type optical sensor having one light emitting mechanism and one light receiving mechanism.

  In the example shown in FIG. 12, the toner detection sensor 65 includes an infrared LED 65a and a phototransistor 65b. The infrared LED 65 a is a light emitting unit that emits infrared light toward the intermediate transfer belt 12. The phototransistor 65b is a transistor that allows a collector current to flow according to the amount of light received. In the toner detection sensor 65, the infrared LED 65a emits infrared light toward the intermediate transfer belt 12, the phototransistor 65b receives the infrared light specularly reflected by the intermediate transfer belt 12, and a collector corresponding to the amount of light. Apply current.

  FIG. 13 is a diagram illustrating the relationship between the remaining amount of residual developer and the output voltage of the toner detection sensor used in the second embodiment. As shown in FIG. 13, when the amount of residual toner RTNout outside the sheet range on the intermediate transfer belt 12 is small, the toner detection sensor 65 increases the intensity of reflected light received by the phototransistor 65b. The output voltage increases. Conversely, if the amount of residual toner RTNout outside the paper range on the intermediate transfer belt 12 is large, the phototransistor 65b has a low intensity of reflected light received by the phototransistor 65b, so the output voltage of the phototransistor 65b becomes small. .

  The mechanism control unit 66 is a functional unit that controls the operation of the main part of the printer 1, similarly to the mechanism control unit 44 (see FIG. 4) of the first embodiment. However, the mechanism control unit 66 can move the toner detection sensor 65 to a predetermined position in accordance with an instruction from the command / image processing unit 42. The mechanism control unit 66 can monitor the output signal of the toner detection sensor 65.

  The toner detection determination unit 67 is a functional unit for determining the removal result of the residual toner RTN. The toner detection determination unit 67 compares the output signal of the toner detection sensor 65 monitored by the mechanism control unit 66 with the toner detection threshold voltage value Vtn (see FIG. 13) stored in advance in the storage unit 68. The comparison result is notified to the mechanism control unit 66.

  The storage unit 68 is a storage unit that stores a toner detection threshold voltage value Vtn (see FIG. 13) in advance.

  Hereinafter, the operation of the printer 1B according to the second embodiment will be described. Here, the operation different from that of the printer 1 according to the first embodiment will be mainly described. Regarding the same operation as that of the printer 1 according to the first embodiment, the operation of the printer 1 according to the first embodiment will be described. Detailed description of the operation of the printer 1B according to 2 will be omitted.

When the printer 1B receives print data from the host device, the printer 1B operates as follows.
First, the command / image processing unit 42 notifies the mechanism control unit 66 of the width information of the paper P used for printing based on the print data.

  The mechanism control unit 66 moves the toner detection sensor 65 to a predetermined position based on the notified width information of the paper P. In the second embodiment, the mechanism control unit 66 moves the toner detection sensor 65 to a position on the area A and the area B outside the sheet range shown in FIG.

  Next, the mechanism control unit 66 controls the driving of the belt motor 47, the drum motor 48, the secondary transfer motor 49, the brush motor 51, and the collection motor 52 to drive the drive roller 13 and each printing mechanism Me2 (K). , Me2 (Y), Me2 (M), Me2 (C), the secondary transfer roller 22, the cleaning brush 36, and the recovery roller 38 are driven.

  At the same time, the mechanism control unit 66 outputs a voltage generation instruction to the high voltage control unit 53. In response to this, the high voltage control unit 53 includes a charging voltage generation unit 54, a supply voltage generation unit 55, a development voltage generation unit 56, a primary transfer voltage generation unit 57, a secondary transfer voltage generation unit 58, and a precharge voltage generation. The unit 59, the cleaning voltage generation unit 60, and the recovery voltage generation unit 61 apply voltages to the corresponding components. As a result, the driving roller 13, the printing mechanisms Me2 (K), Me2 (Y), Me2 (M), Me2 (C), the secondary transfer roller 22, the cleaning brush 36, and the collection roller 38 are driven.

  When the intermediate transfer belt 12 starts running, the mechanism control unit 66 notifies the toner detection determination unit 67 of the output voltage value of the toner detection sensor 65 being monitored.

  The toner detection determination unit 67 compares the notified output voltage value of the toner detection sensor 65 with the toner detection threshold voltage value Vtn stored in the storage unit 68 in advance. In the second exemplary embodiment, the toner detection threshold voltage value Vtn is an output voltage value of the toner detection sensor 65 with a toner amount at a level at which a cleaning failure cannot be recognized as an image.

  When the notified output voltage value of the toner detection sensor 65 is equal to or lower than the toner detection threshold voltage value Vtn, the toner detection determination unit 67 generates an image abnormality due to the residual toner RTNout outside the paper range on the intermediate transfer belt 12. And outputs an instruction to re-execute the toner detection operation to the mechanism control unit 66.

  When the mechanism control unit 66 receives an instruction to re-execute the toner detection operation from the toner detection determination unit 67, the mechanism control unit 66 executes the toner detection operation again. At this time, the cleaning brush 36 of the cleaning mechanism Me5 continues to clean the intermediate transfer belt 12. Therefore, the toner amount of the residual toner RTNout outside the sheet range on the intermediate transfer belt 12 is smaller than that at the first toner detection.

  On the other hand, if the notified output voltage value of the toner detection sensor 65 exceeds the toner detection threshold voltage value Vtn, the toner detection determination unit 67 determines that the residual toner RTNout outside the sheet range does not exist on the intermediate transfer belt 12. Determine and start the printing operation. Since the printing operation is the same as that in the first embodiment, the description thereof is omitted here.

  Thus, the printer 1B repeatedly performs the toner detection operation until the notified output voltage value of the toner detection sensor 65 exceeds the toner detection threshold voltage value Vtn. For this reason, the printer 1B can remove the residual toner RTNout outside the sheet range on the intermediate transfer belt 12 to a level where a defective cleaning cannot be recognized as an image.

  Thus, since the printer 1B has the toner detection sensor 65, the collection roller 38 (see FIG. 9) cannot collect the removed toner rtn from the cleaning brush 36 by the previous printing operation, and the removed toner rtn. Is accumulated in the cleaning brush 36, and as a result, even if the cleaning efficiency of the cleaning brush 36 is reduced, this is detected and the residual toner RTNout outside the paper range is removed. Therefore, the printer 1B can automatically return to the recovered state from the state in which the cleaning efficiency of the cleaning brush 36 has decreased.

As described above, according to the printer 1B according to the second embodiment, even when the cleaning efficiency of the cleaning brush 36 is lowered, this is detected and the residual toner RTNout outside the paper range is removed, and thus the cleaning brush It is possible to return to the recovered state from the state where the cleaning efficiency of 36 is lowered.

  The present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the gist of the present invention.

  For example, in this embodiment, the latent image forming means is an LED head, but a laser light source or the like may be used, and the present invention is not limited to this embodiment.

  For example, in the present embodiment, the apparatus having four printing mechanisms Me2 has been described, but the number of printing mechanisms Me2 is not limited to four.

  Further, for example, in the present embodiment, the intermediate transfer type image forming apparatus 1 has been described, but a direct transfer type image forming apparatus may be used, and the present invention is not limited to this embodiment. When the image forming apparatus is configured as a direct transfer type apparatus, a conveyance belt as a recording medium conveyance body serves as a member to be cleaned instead of the intermediate transfer belt 12. Therefore, in this case, the toner diffusing member 33 as the developer diffusing member is provided in contact with the conveying belt in order to diffuse the developer attached to the surface of the conveying belt. In this case, the cleaning brush 36 as a cleaning member is provided in contact with the transport belt in order to remove the developer attached to the surface of the transport belt.

  Further, for example, the present invention can be used not only in a printer but also in an image forming apparatus such as a facsimile machine, a copying machine, and an MFP.

1,1B Image forming device (printer)
DESCRIPTION OF SYMBOLS 3 Charging roller 4 Photosensitive drum 5 Developing roller 6 Developing blade 7 Supply roller 8 Static electricity source 9 Toner cartridge 10 Primary transfer roller 11 LED head 12 Intermediate transfer belt (member to be cleaned)
Reference Signs List 13 Drive roller 14 Conveyance path 15 Paper storage cassette 16 Hopping roller 17 Pinch roller 18 Registration roller 19 (19A, 19B, 19C) Guide 21 Paper feed sensor 22 Secondary transfer roller (transfer member)
23 Secondary transfer counter roller 24 Paper monitoring sensor 26 Heat roller 27 Pressure roller 28 Heater 29 Thermistor 30 Discharge sensor 31 Stacker 33 Toner diffusion member (developer diffusion member)
33a Brush part 33b Brush holding part 34 Pre-charging brush 34a Brush part 34b Brush holding part 35 Metal plate 36 Cleaning brush (cleaning member)
36a Metal core 36b Brush cloth 37 Cleaning brush counter roller 38 Collection roller (collection member)
39, 63 Cleaning blade 40, 64 Waste toner tank 41 Host interface unit 42 Command / image processing unit 43 LED head interface unit 44 Mechanism control unit 45 Hopping motor 46 Registration motor 47 Belt motor 48 Drum motor 49 Secondary transfer motor 50 Heat roller Motor 51 Brush motor 52 Recovery motor 53 High voltage controller 54 Charging voltage generator 55 Supply voltage generator 56 Development voltage generator 57 Primary transfer voltage generator 58 Secondary transfer voltage generator 59 Precharge voltage generator 60 Cleaning voltage generator 60 Unit 61 Recovery voltage generation unit 65 Toner detection sensor 65a Infrared LED
65b Phototransistor 66 Mechanism control unit 67 Toner detection determination unit 68 Storage means θ1, θ2 Inclination angle L Length of toner diffusion member Lmin Minimum paper width Lmax Maximum paper width Me1 Paper feed mechanism Me2 Printing mechanism (image forming process unit)
Me3 transfer mechanism Me4 fixing mechanism Me5 cleaning mechanism N1 primary transfer nip N2 secondary transfer nip P paper (recording medium)
S1 contact surface TN toner (developer)
RTNin Residual toner within paper range RTNout Residual toner outside paper range RTNd Diffusion residual toner V Printing speed Vtn Toner detection threshold voltage value

Claims (14)

A member to be cleaned carrying a developer;
A developer diffusing member for diffusing the developer remaining on the member to be cleaned;
A cleaning member for removing the developer on the member to be cleaned diffused by the developer diffusing member from the member to be cleaned;
The image forming apparatus, wherein the developer diffusing member is disposed at a position upstream of the cleaning member, and is further inclined with respect to a conveying direction of the member to be cleaned. . The image forming apparatus according to claim 1.
In the developer diffusing member, a central portion in the longitudinal direction of the member to be cleaned is an upstream side and an end portion in the longitudinal direction of the member to be cleaned is a downstream side with respect to the conveying direction of the member to be cleaned. The image forming apparatus is arranged as described above. The image forming apparatus according to claim 1, wherein:
The image forming apparatus, wherein the developer diffusing member is divided into left and right parts with respect to a center of the member to be cleaned in a conveyance direction. The image forming apparatus according to claim 3.
The member to be cleaned is a member that contacts a recording medium,
The developer diffusing member divided into the right and left sides of the member to be cleaned and the recording medium, each including an upstream end including a position on a boundary where the member to be cleaned and the recording medium are in contact with each other. An image forming apparatus, wherein the image forming apparatus is disposed at a position within a contact range, and an end on the downstream side is disposed at a position outside the contact range between the member to be cleaned and the recording medium. The image forming apparatus according to claim 3 or 4, wherein:
2. The image forming apparatus according to claim 1, wherein a plurality of the developer diffusing members divided into right and left are arranged on one or both of the left and right sides. The image forming apparatus according to any one of claims 3 to 5,
2. The image forming apparatus according to claim 1, wherein the developer diffusing member divided into right and left is formed such that one of the left and right sides is longer than the other side. The image forming apparatus according to any one of claims 1 to 6,
The image forming apparatus, wherein the developer diffusing member is in contact with the member to be cleaned. The image forming apparatus according to any one of claims 1 to 7,
The cleaning member is configured as a cleaning brush,
The image forming apparatus further comprises a recovery member for recovering the developer from the cleaning brush. The image forming apparatus according to any one of claims 1 to 8,
The image forming apparatus, wherein the member to be cleaned is an image carrier. The image forming apparatus according to any one of claims 1 to 8,
The image forming apparatus, wherein the member to be cleaned is an intermediate transfer medium. The image forming apparatus according to any one of claims 1 to 8,
The image forming apparatus, wherein the member to be cleaned is a recording medium conveyance body. The image forming apparatus according to any one of claims 1 to 11,
The image forming apparatus according to claim 1, further comprising a developer detector that detects a result of removing the developer from the member to be cleaned by the cleaning member on a downstream side of the cleaning member. The image forming apparatus according to claim 12.
The image forming apparatus, wherein the developer detector detects at least a removal result in a range from a minimum width to a maximum width of a recording medium. The image forming apparatus according to claim 12 or 13,
The image forming apparatus, wherein the developer detector is movable in a direction intersecting with a conveying direction of the member to be cleaned.

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