JP2003162179A - Electrifier, process cartridge and image forming apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent defective electrification and defective recovery due to such effects that toner melts and sticks on an image carrier and an electrifying roller is soiled by the toner, and to prevent the toner on the image carrier from dropping by stabilizing the contact state of a brush for an electrifier which is equipped with sheet-like brush members 3g and 3h arranged facing the image carrier 2 and whose leading ends come into contact with the surface of the image carrier 2, in a cleaner-less type image forming apparatus. <P>SOLUTION: Ribs 11a1 and 11a3 and a sheet are arranged in press contact with the brushes 3g and 3h and on the upstream side of the brushes 3g and 3h in the image carrier moving direction so as to incline the brushes 3g and 3h toward the image carrier moving direction. Members 11a2 and 11a1 and a sheet for controlling the tilt of the bristles of the brushes 3g and 3h are arranged adjacent to the brushes 3g and 3h on the downstream side of the brushes 3g and 3h in the image carrier moving direction. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device, a process cartridge and an image forming apparatus using the same.

More specifically, a charging device (including static eliminator) having a plate-like brush member which is arranged so as to face a member to be charged and whose tip portion is in contact with the surface of the member to be charged, is used. Used process cartridge and electrophotographic method
The present invention relates to an image forming apparatus such as an electrostatic recording type copier or printer.

The electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming process. For example, an electrophotographic copying machine, an electrophotographic printer (LED printer, laser beam printer, etc.), an electrophotographic facsimile machine, and an electrophotographic word processor are included.

A process cartridge is a cartridge in which at least one of a charging means, a developing means, a cleaning means, and an electrophotographic photosensitive member which is an image bearing member are integrally formed as a cartridge.
This cartridge can be attached to and detached from the main body of the image forming apparatus.

The charging device has means for uniformly charging the electrophotographic photosensitive member to a predetermined polarity and potential.

[0006]

2. Description of the Related Art Conventionally, a process in which an electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum), a charging unit, a developing unit, a cleaning unit and the like are integrally formed into a cartridge, and the cartridge can be attached to and detached from an image forming apparatus main body. The cartridge system is adopted.

By this cartridge system, the operability is further improved, and the maintenance of the process means can be easily carried out by the user himself. Therefore, this cartridge system is widely used in the image forming apparatus main body.

Further, there has been realized a cartridge structure in which the process means is divided into one having a long life and one having a short life, each process means is made into a cartridge, and can be used in accordance with the life of the main process means. For example, a developing cartridge in which a toner accommodating portion and a developing unit are integrally configured, or a drum cartridge in which a photosensitive drum, a charging unit, and a cleaning unit are integrally configured is adopted.

Further, in recent years, an image forming process including a step of uniformly charging the photosensitive drum to a predetermined polarity and potential is applied to form a developer image corresponding to image information, and the developer image is formed. A cleaning device is used to transfer the image to the transfer material, output the image-formed product, and remove and collect the developer remaining on the photosensitive drum after the transfer process from the photosensitive drum by cleaning simultaneously with the developing means and reuse it. We have proposed the abolished cleanerless method and are trying to provide a downsized image forming apparatus body.

For example, the charge polarity of the transfer residual developer (hereinafter, referred to as transfer residual toner) remaining on the photosensitive drum after the transfer process, on the downstream side of the transfer means and the upstream side of the charging means in the rotation direction of the photosensitive drum. Is provided with a developer charge amount control unit (hereinafter, referred to as toner charge amount control unit) for adjusting the charge polarity to a regular charge polarity to prevent transfer residual toner adhesion stains on the contact charging member and generate a fog image due to poor charging. A cleanerless type image forming apparatus and a process cartridge which prevent the above-mentioned problems have been proposed (Japanese Patent Laid-Open No. 8-137336).
No. 8).

[0011]

The toner charge amount control means uses a brush-shaped member having an appropriate conductivity, and is arranged so as to face the center of the photosensitive drum. When the photosensitive drum rotates, the tip of the brush portion falls along the rotation direction, but if the tip portion falls down in the direction opposite to the rotation direction during assembly, etc., it will come into contact with the rotation of the photosensitive drum in a counter state. , The transfer residual toner on the photosensitive drum may be scraped off. Also, when the brush portion falls down from the root of the raised portion, the density and contact pressure of the bristles that are in contact with the photosensitive drum become low, and it becomes impossible to sufficiently charge the transfer residual toner, and transfer Since the residual toner cannot be sufficiently charged, there is a problem that the contact charging member is contaminated with the toner.

With the diversification of user needs in recent years, a large amount of transfer can be performed at a time by continuous printing operation of images with a high printing rate such as photographic images and multiple development system on the photosensitive drum with colorization. Due to the generation of residual toner,
It further exacerbates the above-mentioned problems.

In view of this, the present invention relates to a cleaner-less charging device, a process cartridge, and an electrophotographic image forming apparatus equipped with a brush-shaped member such as a developer charge amount control means. Prevents the brush member from scraping off the residual developer on the electrophotographic photosensitive member due to counter contact with the rotating direction of the electrophotographic photosensitive member. The contact pressure and the contact density are stably maintained, and the charge is favorably applied to the transfer residual toner, so that there is no charging failure or a defective image, and the merit of the cleanerless system can be fully utilized. , A charging device, a process cartridge, and an image forming apparatus.

[0014]

The present invention provides a charging device, a process cartridge, and an image forming apparatus using the same, which are characterized by the following configurations.

(1) In a charging device having a plate-like brush member which is disposed so as to face a member to be charged and whose tip portion is in contact with the surface of the member to be charged, the moving direction of the member to be charged is the width direction of the brush member. A charging device provided with a bristle collapse regulating member that regulates the brush member from collapsing from the brush root portion of the brush member in the moving direction due to the movement of the body to be charged on the downstream side.

(2) The bristling restraint member is a rib-shaped member that is close to the downstream side in the widthwise direction of the brush member in the moving direction of the charged body and is continuously long in the longitudinal direction of the brush member. The charging device according to (1).

(3) The charging device according to (2), wherein the rib-shaped member is longer than the brush member.

(4) The bristling restraint member is a flexible sheet, and the free end side tip of the flexible sheet is close to the downstream side surface of the brush member in the moving direction of the charged body in the width direction. The charging device according to (1), which is a flexible sheet that is continuously long in the longitudinal direction of the brush member.

(5) The charging device according to (4), wherein the flexible sheet is longer than the brush member.

(6) The brush member has conductivity,
The charging device according to any one of (1) to (5), which is a charging unit that uniformly charges the surface of the body to be charged.

(7) The charging device according to any one of (1) to (6), wherein the member to be charged is an image carrier that rotates such as an electrophotographic photosensitive member.

(8) The brush member has conductivity,
Positioned upstream of the charging means acting on the image bearing body, which is the member to be charged, in the moving direction of the image bearing body and downstream of the transfer means for transferring the developer image formed on the image bearing body to the transfer material. The developer charge amount control means for charging the residual developer remaining on the image carrier after the transfer step to a predetermined polarity, according to any one of (1) to (7). Charging device.

(9) The brush member has conductivity,
Positioned upstream of the charging means acting on the image bearing body, which is the member to be charged, in the moving direction of the image bearing body and downstream of the transfer means for transferring the developer image formed on the image bearing body to the transfer material. The charging device according to any one of (1) to (7), which is a residual developer image uniformizing means for uniformizing the residual developer image remaining on the image carrier after the transfer step. .

(10) The charging device according to (8) or (9), wherein the image bearing member is a rotating electrophotographic photosensitive member.

(11) In a charging device having a plate-like brush member which is arranged so as to face a member to be charged and whose tip portion is in contact with the surface of the member to be charged, the moving direction of the member to be charged is the width direction of the brush member. A charging device, characterized in that an inclining member for inclining the brush member in the moving direction of the body to be charged is provided on the upstream side.

(12) The tip of the inclined member is in pressure contact with the upstream side surface of the brush member in the width direction of the brush member in the moving direction of the charged body to incline the brush member in the moving direction of the charged body. The charging device according to (11), wherein the charging device is a rib-shaped member that is continuously long in the longitudinal direction.

(13) The charging device according to (12), wherein the rib-shaped member is longer than the brush member.

(14) The inclined member is a flexible sheet, and the free end side tip portion of the flexible sheet is in pressure contact with the upstream side surface in the widthwise direction of the brush member in the moving direction of the charged body. The charging device according to (11), wherein the member is a flexible sheet that is inclined in the moving direction of the member to be charged and is continuously long in the longitudinal direction of the brush member.

(15) The charging device according to (14), wherein the flexible sheet is longer than the brush member.

(16) The inclined member has its tip end pressed against the upstream side surface in the width direction of the brush member in the moving direction of the charged body to incline the brush member in the rotating direction of the charged body, so that the length of the brush member increases. A rib-shaped member that is continuously long in the direction, one end side is further fixed to the rib-shaped member, and the free end side tip portion is in pressure contact with the upstream side surface in the rotational direction of the body to be charged in the width direction of the brush member. The charging device according to (11), characterized in that the member comprises a flexible sheet member that is inclined in the rotation direction of the body to be charged and is continuously long in the longitudinal direction of the brush member.

(17) The charging device according to (16), wherein the rib-shaped member is longer than the brush member, and the flexible sheet member is longer than the brush member.

(18) The brush member has conductivity and is a charging means for uniformly charging the surface of the body to be charged. (11) to (17) Charging device.

(19) The charged body is a rotating image carrier such as an electrophotographic photoreceptor (11).
The charging device according to any one of (18) to (18).

(20) The brush member is electrically conductive, and is formed on the image bearing member upstream of the charging means acting on the image bearing member, which is the member to be charged, in the moving direction of the image bearing member. A developer charge amount control unit that is located on the downstream side of the transfer unit that transfers the developer image to the transfer material and that charges the residual developer remaining on the image carrier after the transfer process to a predetermined polarity. The charging device according to any one of (11) to (19).

(21) The brush member has conductivity, and is formed on the image bearing member upstream of the charging means acting on the image bearing member, which is the member to be charged, in the moving direction of the image bearing member. The residual developer image uniformizing means is located downstream of the transfer means for transferring the developer image to the transfer material and uniformizes the residual developer image remaining on the image carrier after the transfer step. The charging device according to any one of (11) to (19).

(22) The image bearing member is a rotating electrophotographic photosensitive member (20) or (2)
The charging device according to 1).

(23) In a charging device having a plate-like brush member which is disposed so as to face the member to be charged and whose tip portion is in contact with the surface of the member to be charged, the moving direction of the member to be charged is the width direction of the brush member. A bristle collapse regulating member that regulates the brush member on the downstream side from collapsing from the brush root portion of the brush member in the moving direction by the movement of the charged body, and the charged body moving direction in the width direction of the brush member. A charging device comprising an inclined member which is provided on the upstream side to incline the brush member in the moving direction of the body to be charged.

(24) The bristle collapse regulating member is a rib-shaped member that is close to the downstream side in the moving direction of the charged body in the width direction of the brush member and is continuously long in the longitudinal direction of the brush member. The charging device according to (23).

(25) The charging device according to (24), wherein the rib-shaped member is longer than the brush member.

(26) The bristling restraint member is a flexible sheet, and the free end side tip of the flexible sheet is close to the downstream side surface of the brush member in the width direction of the charged member, The charging device according to (23), which is a flexible sheet that is continuously long in the longitudinal direction of the brush member.

(27) The charging device according to (26), wherein the flexible sheet is longer than the brush member.

(28) The inclined member has a tip portion in pressure contact with an upstream side surface of the brush member in the width direction of the brush member in the moving direction of the charged body to incline the brush member in the moving direction of the charged body. The charging device according to (23), wherein the charging device is a rib-shaped member that is continuously long in the longitudinal direction.

(29) The charging device according to (28), wherein the rib-shaped member is longer than the brush member.

(30) The inclined member is a flexible sheet, and the free end side tip portion of the flexible sheet is in pressure contact with the upstream side surface in the moving direction of the charged body in the width direction of the brush member. The charging device according to (23), wherein the member is a flexible sheet that is inclined in the moving direction of the member to be charged and is continuously long in the longitudinal direction of the brush member.

(31) The charging device according to (30), wherein the flexible sheet is longer than the brush member.

(32) The inclined member has its tip end pressed against the upstream side surface in the width direction of the brush member in the moving direction of the charged body to incline the brush member in the moving direction of the charged body. A rib-shaped member that is continuously long in the direction, one end side of which is further fixed to the rib-shaped member, and the free end side tip portion is in pressure contact with the upstream side surface in the moving direction of the charged member in the width direction of the brush member. The charging device according to (23), wherein the charging member is inclined in the moving direction of the body to be charged and is composed of a flexible sheet member that is continuously long in the longitudinal direction of the brush member.

(33) The charging device according to (32), wherein the rib-shaped member is longer than the brush member and the flexible sheet member is longer than the brush member.

(34) The brush member is electrically conductive and is a charging means for uniformly charging the surface of the body to be charged. (23) to (33) Charging device.

(35) The charged body is a rotating image carrier such as an electrophotographic photoreceptor (23).
To (34) the charging device.

(36) The brush member is electrically conductive, and is formed on the image bearing member upstream of the charging means acting on the image bearing member, which is the member to be charged, in the moving direction of the image bearing member. A developer charge amount control unit that is located on the downstream side of the transfer unit that transfers the developer image to the transfer material and that charges the residual developer remaining on the electrophotographic photosensitive member after the transfer process to a predetermined polarity. The charging device according to any one of (23) to (35), characterized in that.

(37) The brush member has conductivity, and is formed on the image bearing member upstream of the charging means acting on the image bearing member, which is the member to be charged, in the moving direction of the image bearing member. It is a residual developer image homogenizing unit that is located downstream of the transfer unit that transfers the developer image to the transfer material and that homogenizes the residual developer image that remains on the image bearing optical body after the transfer process. The charging device according to any one of (23) to (35), which is characterized.

(38) The image bearing member is a rotating electrophotographic photosensitive member (36) or (3)
The charging device according to 7).

(39) At least an image bearing member, and a charging means having a plate-like brush member which is disposed so as to face the image bearing member and whose tip portion is in contact with the surface of the image bearing member. In the process cartridge that is attached to and detached from the main body of the forming apparatus, an inclination member for inclining the brush member in the image carrier moving direction is provided on the upstream side in the image carrier moving direction in the width direction of the brush member. And process cartridge.

(40) The inclined member has a tip portion pressed against an upstream side surface in the width direction of the brush member in the moving direction of the image carrier to incline the brush member in the moving direction of the image carrier. (39) The process cartridge according to (39), which is a rib-shaped member that is continuously long in the longitudinal direction.

(41) The process cartridge described in (40), wherein the rib-shaped member is longer than the brush member.

(42) The inclined member is a flexible sheet, and the free end side tip portion of the flexible sheet is pressed against the upstream side surface of the brush member in the moving direction of the image carrier in the width direction of the brush member. (39) The process cartridge according to (39), wherein the member is a flexible sheet which is inclined in the moving direction of the image carrier and is continuously long in the longitudinal direction of the brush member.

(43) The process cartridge according to (42), wherein the flexible sheet is longer than the brush member.

(44) The inclined member has its tip end pressed against the upstream side surface in the image carrier moving direction in the width direction of the brush member so as to incline the brush member in the image carrier moving direction, and thus the longitudinal direction of the brush member. A rib-shaped member that is continuously long in the direction, and one end side is further fixed to the rib-shaped member, and the free end side tip portion is in pressure contact with the upstream side surface in the image carrier moving direction in the width direction of the brush member. The process cartridge according to (39), characterized in that the flexible sheet member is inclined in the moving direction of the image carrier and is continuously long in the longitudinal direction of the brush member.

(45) The process cartridge according to (44), wherein the rib-shaped member is longer than the brush member, and the flexible sheet member is longer than the brush member.

(46) The brush member is electrically conductive and is a charging means for uniformly charging the surface of the image carrier. (39) to (45) Process cartridge.

(47) The brush member has conductivity, and the developer image formed on the image bearing member is upstream of the charging means acting on the image bearing member in the moving direction of the image bearing member. It is a developer charge amount control means which is located on the downstream side of the transfer means for transferring to the transfer material and charges the residual developer remaining on the image carrier after the transfer step to a predetermined polarity. The process cartridge according to any one of (39) to (45).

(48) The brush member has conductivity, and the developer image formed on the image bearing member is located upstream of the charging means acting on the image bearing member in the moving direction of the image bearing member. The residual developer image homogenizing means is located downstream of the transfer means for transferring to the transfer material and uniformizes the residual developer image remaining on the image carrier after the transfer step (39). ) To (45), the process cartridge.

(49) The process cartridge according to any one of (39) to (48), further comprising a developing device for visualizing the electrostatic latent image on the surface of the image carrier into a developer image.

(50) The image bearing member is a rotating electrophotographic photosensitive member (39) to (49)
The process cartridge according to any one of 1.

(51) At least an image carrier, and a charging means having a plate-like brush member which is arranged so as to face the image carrier and has a tip portion in contact with the surface of the image carrier. In the process cartridge that is attached to and detached from the main body of the forming apparatus, the brush member is moved downstream in the moving direction of the image carrier in the width direction of the brush member from the brush root of the brush member in the moving direction by the movement of the image carrier. A hair fall restricting member for restricting hair fall, and an inclination member for inclining the brush member in the image carrier moving direction on the upstream side in the image carrier moving direction in the width direction of the brush member, Process cartridge.

(52) The bristling restraint member is a rib-shaped member that is close to the downstream side in the moving direction of the image carrier in the width direction of the brush member and is continuously long in the longitudinal direction of the brush member. The process cartridge according to (51).

(53) The process cartridge according to (52), wherein the rib-shaped member is longer than the brush member.

(54) The hair collapse regulating member is a flexible sheet, and the free end side tip portion of the flexible sheet is close to the downstream side surface in the image carrier moving direction in the width direction of the brush member, (51) The process cartridge according to (51), which is a flexible sheet that is continuously long in the longitudinal direction of the brush member.

(55) The process cartridge according to (54), wherein the flexible sheet is longer than the brush member.

(56) The tip of the tilting member is pressed against the upstream side surface of the brush member in the width direction of the brush member in the moving direction of the image carrier to tilt the brush member in the moving direction of the image carrier. (51) The process cartridge according to (51), which is a rib-shaped member that is continuously long in the longitudinal direction.

(57) The process cartridge according to (56), wherein the rib-shaped member is longer than the brush member.

(58) The inclined member is a flexible sheet, and the free end side tip portion of the flexible sheet is in pressure contact with the upstream side surface in the moving direction of the image carrier in the width direction of the brush member. The process cartridge according to (51), wherein the member is inclined in the moving direction of the image carrier and is a flexible sheet which is continuously long in the longitudinal direction of the brush member.

(59) The tip end of the tilting member comes into pressure contact with the upstream side surface of the brush member in the width direction of the brush member so that the brush member is tilted in the moving direction of the image carrier. A rib-shaped member that is continuously long in the direction, and one end side is further fixed to the rib-shaped member, and the free end side tip portion is in pressure contact with the upstream side surface in the image carrier moving direction in the width direction of the brush member. The process cartridge according to (51), characterized in that the flexible sheet member is inclined in the moving direction of the image carrier and is continuously long in the longitudinal direction of the brush member.

(60) The process cartridge according to (59), wherein the rib-shaped member is longer than the brush member, and the flexible sheet member is longer than the brush member.

(61) The brush member is electrically conductive and is a charging means for uniformly charging the surface of the image bearing member. (51) to (59) Process cartridge.

(62) The brush member has conductivity, and the developer image formed on the image bearing member is upstream of the charging means acting on the image bearing member in the moving direction of the image bearing member. It is a developer charge amount control means which is located on the downstream side of the transfer means for transferring to the transfer material and charges the residual developer remaining on the image carrier after the transfer step to a predetermined polarity. The process cartridge according to any one of (51) to (60).

(63) The brush member has conductivity, and the developer image formed on the image carrier is upstream of the charging means acting on the image carrier in the moving direction of the image carrier. It is characterized in that it is a residual developer image homogenizing means which is located on the downstream side of the transfer means for transferring to the transfer material and uniformizes the residual developer image remaining on the image carrier after the transfer step (51). ) To (60), the process cartridge.

(64) The process cartridge according to any one of (51) to (63), further comprising a developing device for visualizing the electrostatic latent image on the surface of the image carrier into a developer image.

(65) The image carrier is a rotating electrophotographic photosensitive member (51) to (64).
The process cartridge according to any one of 1.

(66) In an image forming apparatus provided with an image carrier and a charging device having a plate-like brush member which is arranged so as to face the image carrier and whose tip portion is in contact with the surface of the image carrier, An image forming apparatus, wherein the charging device is the charging device according to any one of (1) to (38).

(67) Process cartridge In the detachable image forming apparatus, the process cartridge is (39)
An image forming apparatus, wherein the image forming apparatus is the process cartridge according to any one of (65) to (65).

(68) At least an electrophotographic photosensitive member which is an image bearing member, and a developing device which visualizes an electrostatic latent image on the surface of the electrophotographic photosensitive member into a developer image as a process means which acts on the electrophotographic photosensitive member. And a charging means having a plate-like brush member arranged toward the center of the electrophotographic photosensitive member and having a tip end in contact with the surface of the electrophotographic photosensitive member. In the widthwise direction of the electrophotographic photosensitive member on the downstream side in the rotation direction, the brush member is regulated by the rotation of the electrophotographic photosensitive member in the rotational direction to prevent the hair from falling from the brush root portion of the brush member, and And an inclination member for inclining the brush member in the rotation direction of the electrophotographic photosensitive member on the upstream side in the rotation direction of the electrophotographic photosensitive member in the width direction of the brush member. Mounting means for removably mounting process cartridge, mounting means for freely mounting process cartridge, driving means for driving the process cartridge, and transfer means for transferring the developer image formed on the image carrier to a recording medium. An image forming apparatus, comprising: and a conveying unit configured to convey the recording medium.

[0083]

BEST MODE FOR CARRYING OUT THE INVENTION A color electrophotographic image forming apparatus according to one embodiment will be described below with reference to the drawings. In the following description, the longitudinal direction is a direction orthogonal to the conveyance direction of the recording medium 52 and is the same as the axial direction of the electrophotographic photosensitive member (hereinafter, photosensitive drum) 2. The left and right are the recording medium 52
Left and right when viewed from the conveyance direction of. Furthermore, the upper and lower sides are the upper and lower sides in the mounted state of the cartridge.

[General Description of Image Forming Apparatus] First, the general structure of the color electrophotographic image forming apparatus will be schematically described with reference to FIG. FIG. 1 is a diagram illustrating the overall configuration of a color laser beam printer which is one form of a color toner image forming apparatus.

The image forming section of this color laser beam printer includes four process cartridges 1Y, 1M, 1C and 1K (yellow, magenta, cyan and black) having a photosensitive drum 2 as an image carrier. , Above the process cartridges 1Y, 1M, 1C and 1K, exposing means 51Y, 51M, 51C corresponding to the respective colors,
51K (laser beam optical scanning system) are arranged in parallel.

Below the image forming section, a recording medium 52 is provided.
For feeding the toner image formed on the photosensitive drum 2, and the toner image on the intermediate transfer belt 54a is transferred to the recording medium 52.
The next transfer roller 54d is arranged.

Further, the recording medium 5 on which the toner image is transferred
The fixing means for fixing the second recording medium 2 and the discharging means for discharging and stacking the recording medium 52 outside the apparatus are arranged.

Here, the recording medium 52 is, for example, paper, OHP sheet, cloth, or the like.

The image forming apparatus of this embodiment is a cleanerless system apparatus, in which the transfer residual toner remaining on the photosensitive drum 2 is taken into the developing means, and the exclusive cleaner for collecting and storing the transfer residual toner is in the process cartridge. Not placed in.

Next, the configuration of each part of the image forming apparatus will be sequentially described in detail.

[Paper Feeding Unit] The paper feeding unit feeds the recording medium 52 to the image forming unit, and includes a feeding cassette 53a in which a plurality of recording media 52 are stacked and stored, and a feeding roller 53.
b, retard roller 53c for preventing double feeding, feeding guide 53
d, the registration roller 53g.

The feeding roller 53b is driven and rotated in accordance with the image forming operation to separate and feed the recording media 52 in the feeding cassette 53a one by one. The recording medium 52 is a feeding guide 53.
It is guided by d and is conveyed to the registration roller 53g via the conveyance rollers 53e and 53f.

Immediately after the recording medium 52 is conveyed, the registration rollers 53g stop rotating, and the skew of the recording medium 52 is corrected by hitting the nip portion.

Registration roller 53g during image forming operation
Performs a non-rotational operation in which the recording medium 52 stands by in a stationary state and a rotational operation in which the recording medium 52 is conveyed toward the intermediate transfer belt 54a in a predetermined sequence. Positioning with the recording medium 52 is performed.

[Process Cartridge] The process cartridges 1Y, 1M, 1C and 1K are integrally formed by disposing the charging means and the developing means around the photosensitive drum 2 which is an image carrier. The process cartridge can be easily removed by the user from the apparatus main body, and is replaced when the photosensitive drum 2 reaches the end of its life.

In this embodiment, for example, the number of rotations of the photosensitive drum 2 is counted, and when the number of counts exceeds a predetermined number, the fact that the process cartridge has reached the end of its life is notified.

The photosensitive drum 2 of this example is a negatively charged organic photosensitive member, which has a photosensitive member layer which is usually used on an aluminum drum base having a diameter of about 30 mm, and a charge injection layer is provided on the outermost layer. ing. Then, it is rotationally driven at a predetermined process speed, in this example, about 117 mm / sec.

The charge injection layer is a binder of an insulating resin.
As the conductive fine particles, for example, SnO ₂Disperse ultrafine particles
It uses a coating layer of different materials.

As shown in FIG. 4, a drum flange 2b is fixed to the rear end of the photosensitive drum 2, and a non-driving flange 2d is fixed to the front end thereof. Drum flange 2
The drum shaft 2a passes through the centers of b and the non-driving flange 2d, and the drum shaft 2a, the drum flange 2b, and the non-driving flange 2d are integrally rotated. That is,
The photosensitive drum 2 is rotated about the axis of the drum shaft 2a.

The front end of the drum shaft 2a is rotatably supported by a bearing 2e, which is fixed to the bearing case 2c. The bearing case 2c is fixed to the frame of the process cartridge.

[Charging Means] The charging means 3 uses a contact charging method. In this example, the charging roller 3a is used as the charging member.

As shown in FIG. 2, the charging roller 3a rotatably holds both ends of a cored bar 3b by bearing members (not shown), and biases the charging roller 3a toward the photosensitive drum by a pressing spring 3d. The surface of the photosensitive drum 2 is pressed against the surface of the photosensitive drum 2 with a predetermined pressing force, and is rotated by the rotation of the photosensitive drum 2.

Reference numeral 3c is a charging roller cleaning member, which is a flexible cleaning film in this example. The cleaning film 3e is arranged in parallel to the longitudinal direction of the charging roller 3a, and has one end fixed to a support member 3f that reciprocates a certain amount in the longitudinal direction. Arranged to form a contact nip. The supporting member 3f is reciprocally driven in the longitudinal direction by a certain amount by a driving unit (not shown), and the surface of the charging roller is rubbed with the cleaning film 3e. As a result, the adhered substances (fine powder toner,
External additives, etc.) are removed.

[Cleanerless System] The outline of the cleanerless system in the image forming apparatus of this example will be described with reference to FIG. 2. The transfer residual toner on the photosensitive drum 2 after transfer is caused by the subsequent rotation of the photosensitive drum. Charging part a,
After passing through the exposure section b and carried to the development section c, the development device 4
The cleaning (recovery) is carried out simultaneously with the development.

Since the transfer residual toner on the surface of the photosensitive drum 2 passes through the exposure portion b, the exposure process is performed on the transfer residual toner. However, since the amount of transfer residual toner is small, a great influence does not appear.

However, the transfer residual toner includes a normal polarity toner, a reverse polarity toner (reversal toner), and a toner having a small charge amount, and the reverse toner and the toner having a low charge amount are included in the charging portion a. When the charging roller 3a adheres to the charging roller 3a when passing, the charging roller 3a undesirably contaminates the toner and causes charging failure.

Further, in order to effectively perform the simultaneous cleaning of the transfer residual toner on the surface of the photosensitive drum 2 by the developing device 4, the charging polarity of the transfer residual toner on the photosensitive drum 2 carried to the developing section c is set. -It is necessary that the polarity is such that the electrostatic latent image on the photosensitive drum 2 can be developed by the developing device 4. The reversal toner and the toner having an inappropriate charge amount cannot be removed / collected from the photosensitive drum 2 to the developing device 4, which causes a defective image.

With the diversification of user needs in recent years, a large amount of transfer residual toner is generated at one time due to continuous printing operation of images with a high printing rate such as photographic images, which further promotes the problems described above. I will let you.

Therefore, in this example, the photosensitive drum 2 is provided at a position downstream of the transfer portion d in the photosensitive drum rotation direction.
The transfer residual toner (residual developer image) uniformizing means 3g for uniformizing the transfer residual toner is provided. At the position on the upstream side of the drum rotation direction,
Toner (developer) charge control means 3h is provided for adjusting the charge polarity of the transfer residual toner to the negative polarity which is the normal polarity.

By providing the transfer residual toner equalizing means 3g, the pattern transfer residual toner carried on the photosensitive drum from the transfer portion d to the toner charging control means 3h is exposed even if the toner amount is large. Since the toner is not distributed on the drum surface and is not patterned, the toner is not concentrated on a part of the toner charging control means 3h, and the transfer residual toner is charged to the normal polarity as a whole by the toner charging control means 3h. The processing is always sufficiently performed to effectively prevent the transfer residual toner from adhering to the charging roller 3a. Further, generation of a ghost image of the transfer residual toner image pattern is also prevented.

In this example, the transfer residual toner uniformizing means 3g
The toner charging control means 3h is a brush-shaped member having an appropriate conductivity, and the brush portion is arranged in contact with the surface of the photosensitive drum.

Further, these means move (reciprocate) in the longitudinal direction of the photosensitive drum by a driving source (not shown). By doing so, the transfer residual toner equalizing means 3g and the toner charging control means 3h do not continue to be positioned at the same position on the photosensitive drum, and, for example, an overcharged portion or charging due to uneven resistance of the toner charging control means 3h occurs. Even if there is a shortage portion, it does not always occur on the same photosensitive drum surface portion, and therefore, a small amount of transfer residual toner overcharge causes fusion on the photosensitive drum, and insufficient charging results in charging roller 3a. The transfer residual toner is prevented or alleviated from adhering.

[Exposure Means] In this example, the exposure means 51Y, 51M, 51C and 51K for the photosensitive drum 2 are laser exposure means. That is, when an image signal is sent from the apparatus main body, the laser light L modulated corresponding to this signal is scanned and exposed on the uniformly charged surface of the photosensitive drum 2. Then, an electrostatic latent image corresponding to the image information is selectively formed on the surface of the photosensitive drum 2.

The laser exposure means is a solid-state laser element (not shown), a polygon mirror 51a, an imaging lens 51.
b, a reflection mirror 51c and the like. Based on the input image signal, the light emission signal generator (not shown) controls ON / OFF light emission of the solid-state laser element at a predetermined timing. The laser light L emitted from the solid-state laser element is converted into a substantially parallel light flux by a collimator lens system (not shown) and scanned by the polygon mirror 51a which rotates at high speed. Then, an image is formed in a spot shape on the photosensitive drum 2 via the imaging lens 51b and the reflection mirror 51c.

As described above, the surface of the photosensitive drum 2 is exposed in the main scanning direction by laser beam scanning and further in the sub-scanning direction by the rotation of the photosensitive drum 2, and the exposure distribution according to the image signal is obtained. can get. That is, the light portion potential whose surface potential has dropped due to the irradiation and non-irradiation of the laser light L,
Otherwise, a dark space potential is formed. Then, an electrostatic latent image corresponding to the image information is formed by the contrast between the light portion potential and the dark portion potential.

[Developing means] Developing device 4 which is a developing means
Is a two-component contact developing device (two-component magnetic brush developing device)
As shown in FIG. 2, the developer composed of the carrier and the toner is held on the developing sleeve 4a which is the developer carrying member including the magnet roller 4b. A restriction blade 4c is provided on the developing sleeve 4a with a predetermined gap, and a thin layer of developer is formed on the developing sleeve 4a as the developing sleeve 4a rotates in the arrow direction.

The developing sleeve 4a, as shown in FIG.
Spacers 4 are attached to the reduced diameter journal portions 4a1 on both sides thereof.
When k is rotatably fitted, it is arranged so as to have a predetermined gap with the photosensitive drum 2, and at the time of development, the developer formed on the developing sleeve 4a can be developed while being in contact with the photosensitive drum 2. Is set. The developing sleeve 4a is rotationally driven at a predetermined peripheral speed in the developing portion in a clockwise direction indicated by an arrow, which is a counter direction with respect to a rotating direction of the photosensitive drum 2.

The toner used in this example has an average particle size of 6
A negatively charged toner of μm was used, and a magnetic carrier having a saturation magnetization of 205 emu / cm ^{3 and} an average particle diameter of 35 μm was used. A mixture of toner and carrier in a weight ratio of 6:94 is used as a developer.

Developer storage section 4h in which the developer is circulated
Is divided into two by a longitudinal partition 4d except for both ends. The stirring screws 4eA and 4eB are arranged so as to sandwich the partition wall 4d.

As shown in FIG. 4, the toner replenished from the toner replenishing container 5 falls to the inner side of the stirring screw 4eB and is agitated while being sent to the front side in the longitudinal direction. Pass through. Then, it is further sent to the inner side in the longitudinal direction by the agitating screw 4eA, passes through the part without the partition wall 4d on the inner side, is agitated while being sent by the agitating screw 4eB, and repeats circulation.

The developing process for developing the electrostatic latent image formed on the photosensitive drum 2 by the two-component magnetic brush method using the developing device 4 and the developer circulation system will be described below.

With the rotation of the developing sleeve 4a, the developer in the developing container is pumped up to the surface of the developing sleeve 4a by the scooping pole of the magnet roller 4b and conveyed.

In the course of the transportation, the layer thickness of the developer is regulated by the regulating blade 4c arranged perpendicularly to the developing sleeve 4a, and the thin layer developer is formed on the developing sleeve 4a. When the thin layer developer is conveyed to the developing pole corresponding to the developing section, the magnetic force causes the formation of ears. The electrostatic latent image on the surface of the photosensitive drum 2 is developed as a toner image by the toner in the developer formed in the spike shape. In this example, the electrostatic latent image is reversely developed.

The thin layer developer on the developing sleeve 4a which has passed through the developing portion continues to enter the developing container with the rotation of the developing sleeve 4a, and is separated from the developing sleeve 4a by the repulsive magnetic field of the carrier pole to be stored in the developing container. It is returned to the developer pool.

Direct current (DC) voltage and alternating current (AC) voltage are applied to the developing sleeve 4a from a power source (not shown). In this example, a DC voltage of -500V and a frequency of 200
An AC voltage having a peak-to-peak voltage of 1500 V is applied at 0 Hz, and only the exposed portion of the photosensitive drum 2 is selectively developed.

Generally, in the two-component developing method, when an AC voltage is applied, the developing efficiency increases and the quality of the image becomes high, but on the contrary, there is a risk that fogging is likely to occur. Therefore, normally, by providing a potential difference between the DC voltage applied to the developing sleeve 4a and the surface potential of the photosensitive drum 2,
Achieved to prevent fogging. More specifically, a bias voltage having a potential between the potential of the exposed portion and the potential of the non-exposed portion of the photosensitive drum 2 is applied.

When the toner is consumed by the development, the toner density in the developer decreases. In this example, the sensor 4g for detecting the toner concentration is arranged at a position close to the outer peripheral surface of the stirring screw 4eB. When the sensor 4g detects that the toner concentration in the developer has dropped below a predetermined concentration level, an instruction to replenish the toner in the developing device 4 is issued from the toner replenishing container. By this toner supply operation, the toner concentration of the developer is always maintained and controlled at a predetermined level.

[Toner supply container] Toner supply container 5Y,
5M, 5C and 5K are process cartridges 1Y and 1
They are arranged in parallel above M, 1C and 1K and are mounted from the front of the apparatus main body 100.

As shown in FIG. 2, a stirring plate 5b fixed to a stirring shaft 5c and a screw 5a inside the toner supply container.
And a discharge opening 5f for discharging toner is formed on the bottom surface of the container. As shown in FIG. 5, both ends of the screw 5a and the stirring shaft 5c are rotatably supported by bearings 5d, and a drive coupling (concave) 5e is provided at one of the outermost ends.
Are arranged. The drive coupling (concave) 5e receives a drive transmission from the drive coupling (convex) 62b of the apparatus body and is rotationally driven. The outer shape of the screw 5a has a spiral rib shape, and the twisting direction of the spiral is reversed around the discharge opening 5f. The screw is rotated in a predetermined rotation direction by the rotation of the drive coupling (convex) 62b. Then, the toner is conveyed toward the discharge opening 5f, the toner is allowed to fall freely from the opening of the discharge opening 5f, and the toner is supplied to the developing device 4 of the process cartridge.

The tip of the stirring plate 5b in the direction of the radius of rotation is inclined, and when it comes into sliding contact with the wall surface of the toner supply container, the tip is abutted at an angle. In particular,
The tip side of the stirring plate 5b is twisted into a spiral state.
In this way, the tip end side of the stirring plate 5b is twisted and inclined to generate a conveying force in the axial direction, and the toner is sent in the longitudinal direction.

The toner replenishing container of this embodiment is not limited to the two-component developing method and can be replenished not only in the process cartridge or the developing cartridge using the one-component developing method, but also in the powder contained in the toner replenishing container. Is not limited to toner, but toner and magnetic carrier are mixed,
It goes without saying that it may be a so-called developer.

[Transfer Unit] The intermediate transfer unit 54, which is a transfer unit, collectively transfers a plurality of toner images, which are sequentially primary-transferred from the photosensitive drum 2 and superposed, onto the recording medium 52.
It is the next transcription.

The intermediate transfer unit 54 is provided with an intermediate transfer belt 54a which runs in the direction of the arrow, and runs in the clockwise direction of the arrow at a peripheral speed substantially the same as the peripheral speed of the photosensitive drum 2. This intermediate transfer belt 54a has a circumference of about 940 mm.
Is an endless belt and is wound around by three rollers of a driving roller 54b, a secondary transfer opposing roller 54g, and a driven roller 54c.

Further, in the intermediate transfer belt 54a, transfer charging rollers 54fY, 54fM, 54fC and 54fK are provided.
Are rotatably arranged at positions facing the photosensitive drums 2,
The pressure is applied toward the center of the photosensitive drum 2.

Transfer charging rollers 54fY, 54fM, 54
fC and 54fK are supplied with power from a high voltage power source (not shown), and are charged from the back side of the intermediate transfer belt 54a in the opposite polarity to the toner, and the toner images on the photosensitive drum 2 are sequentially transferred to the intermediate transfer belt 5.
Primary transfer is performed on the upper surface of 4a.

In the secondary transfer portion, a secondary transfer roller 54d as a transfer member is pressed against the intermediate transfer belt 54a at a position opposed to the secondary transfer counter roller 54g. The secondary transfer roller 54d can swing up and down in the drawing and can rotate. At this time, a bias is simultaneously applied to the intermediate transfer belt 54a, so that the toner image on the intermediate transfer belt 54a is transferred to the recording medium 52.

Here, the intermediate transfer belt 54a and the secondary transfer roller 54d are driven. When the recording medium 52 enters the secondary transfer portion, a predetermined bias is applied to the secondary transfer roller 54d, and the toner image on the intermediate transfer belt 54a is secondarily transferred to the recording medium 52.

At this time, the recording medium 5 sandwiched between them.
At the same time as the transfer step is performed, the sheet No. 2 is conveyed leftward in the drawing at a predetermined speed toward the fixing device 56 which is the next step.

At a predetermined position of the intermediate transfer belt 54a, which is the most downstream side of the transfer process, a cleaning unit which can be brought into contact with and separated from the surface of the intermediate transfer belt 54a is provided to remove the transfer residual toner remaining after the secondary transfer. To do.

In the cleaning unit 55, a cleaning blade 55a for removing the transfer residual toner is arranged. The cleaning unit 55 is attached so as to be swingable around a rotation center (not shown), and the cleaning blade 55a is in pressure contact with the intermediate transfer belt 54a in a direction in which it bites. The transfer residual toner taken into the cleaning unit 55 is transported to and stored in a waste toner tank (not shown) by the feed screw 55b.

Here, as the intermediate transfer belt 54a, one made of a polyimide resin can be used. Other materials are not limited to polyimide resins, but include polycarbonate resins, polyethylene terephthalate resins, polyvinylidene fluoride resins, polyethylene naphthalate resins, polyether ether ketone resins, polyether sulfone resins, polyurethane resins, and other plastics. Alternatively, fluorine-based or silicon-based rubber can be preferably used. [Fixing section] The toner image formed on the photosensitive drum 2 by the developing unit is transferred onto the recording medium 52 via the intermediate transfer belt 54a. . Then, the fixing device 56 uses the heat to transfer the toner image transferred onto the recording medium 52.
Fix it on.

As shown in FIG. 1, the fixing device 56 includes a fixing roller 56a for applying heat to the recording medium 52 and a pressure roller 56b for pressing the recording medium 52 to the fixing roller 56a. The roller is a hollow roller. Each has a heater (not shown) inside. Then, the recording medium 52 is simultaneously conveyed by being rotationally driven.

That is, the recording medium 52 holding the toner image is conveyed by the fixing roller 56a and the pressure roller 56b, and the toner image is fixed on the recording medium 52 by applying heat and pressure.

The recording medium 52 after fixing has a discharge roller 53.
It is discharged by h and 53j and loaded on the tray 57 on the apparatus main body 100.

[Mounting of Process Cartridge and Toner Supply Container] Next, the procedure of mounting the process cartridge and toner supply container will be described with reference to FIGS. 2, 3, 4 and 5. A front door 58 that can be opened and closed is arranged on the front surface of the apparatus main body 100. When the front door 58 is opened to the front, an opening for inserting a process cartridge and a toner supply container is exposed.

A rotatably supported centering plate 59 is arranged in the opening for inserting the process cartridge, and the process cartridge is inserted and removed after the centering plate 59 is opened.

A guide rail 60 for guiding the mounting of the process cartridge and a guide rail 61 for guiding the mounting of the toner supply container are fixed in the apparatus main body 100.

The mounting direction of the process cartridge and the toner supply container is parallel to the axial direction of the photosensitive drum 2, and the guide rails 60 and 61 are also arranged in the same direction. The process cartridge and toner supply container are
Once along the guide rails 60 and 61, the apparatus main body 1
It is slid and inserted from the front to the back in 00.

When the process cartridge is inserted all the way to the innermost part, the centering shaft 66 of the apparatus main body is inserted into the center hole 2f of the drum flange 2b, and the rotation center position on the inner side of the photosensitive drum 2 is relative to the apparatus main body. Can be decided At the same time, the drive transmission portion 2g formed on the drum flange 2b and the drive coupling (convex) 62a are connected to each other, and
Can be driven to rotate. Drive transmission unit 2g used in this example
Has a twisted triangular prism shape, and the driving force is transmitted from the main body to transmit the driving force.
The force that pulls in is generated. Further, a support pin 63 for positioning the process cartridge is arranged on the rear side plate 65, and the support pin 63 is inserted into the frame of the process cartridge to fix the position of the frame of the process cartridge.

A rotatable centering plate 59 is arranged on the front side of the apparatus main body 100, and the bearing case 2c of the process cartridge is supported and fixed to the centering plate 59. By this series of insertion operations, the photosensitive drum 2 and the process cartridge are positioned with respect to the apparatus main body.

On the other hand, when the toner supply container is inserted to the innermost part, it is fixed to the support pin 64 protruding from the rear side plate 65. At the same time, drive coupling (concave)
5e and the drive coupling (convex) 62b are connected, and the screw 5a and the stirring shaft 5c can be rotationally driven.

[Embodiment 1] Next, Embodiment 1 of the charging means will be described. 6 is a schematic perspective view of a charging means adopting a cleanerless system, FIG. 7 is a schematic sectional view of the charging means, FIG. 8 is a schematic front view of the charging means, and FIG. 9 is a schematic sectional view of a brush unit of the charging means. is there.

(Structure of Brush Unit of Charging Means) The transfer residual toner equalizing means 3g and the toner charge amount controlling means 3h
In the brush unit 3j, which is a unit, the transfer residual toner equalizing means 3g is fixedly supported on the brush base 11a, and the brush base 11a is fixed to the base frame 12 made of sheet metal by heat, screws, double-sided tape or the like. Similarly, the toner charge amount control means 3h is fixedly supported on the brush base 11b, and the brush base 11b is fixed to the base frame 12. Shafts 13a, 13b, 13c, 3d extend from both ends of the base frame 12, and the transmission arm member 1 is attached to the shafts 13a, 13b on one side (driving side).
4 is attached. Transfer residual toner equalizing means 3g
The toner charge amount control means 3h and the toner charge amount control means 3h are arranged at an angle so as to face the center of the photosensitive drum 2. As described above, in the brush unit 3j, the transfer residual toner equalizing means 3g and the toner charge amount control means 3h are attached to the base frame 12 and integrated, respectively, and the transfer residual toner equalizing means 3g and the toner charge amount control means are integrated. Reference numeral 3h is a unit used such that its tip end contacts the surface of the photosensitive drum 2.

(Drive Structure of Brush Unit) Charging Means 3
Has a coupling gear 15 as a drive transmission means and a reciprocating cam 16 on one end side in the longitudinal direction, and is rotatably fitted and supported by the frame 3k of the charging means 3. The reciprocating cam 16 is a cam gear 1 that meshes with the coupling gear 15.
6a and a cam 16b, and a cam gear 16a and a cam 16
The cam groove 16c is formed by b and is connected to rotate together. The protruding portion 14a of the transmission arm member 14 of the brush unit 3j is fitted in the cam groove 16c. When mounted on the main body of the image forming apparatus, a main body coupler (not shown) is fitted with the coupling gear 15 to transmit the rotational driving force,
The reciprocating cam 16 that meshes with the coupling gear 15 rotates.

When the reciprocating cam 16 rotates, the cam groove 1
The transmission arm member protruding portion 14a of the brush unit 3j fitted in 6c is moved in the longitudinal direction along the cam groove 16c, and reciprocates. In this example, the reciprocating motion is performed at a constant cycle within a range of about 0.5 to 2.5 seconds with a stroke of 5 mm.

(Brush Bristling Regulation and Inclination Structure) In the brush unit 3j described above, the transfer residual toner equalizing means 3g, which is a brush-like member, and the toner charge amount control means 3 are provided.
h is oriented toward the center of the photosensitive drum 2 with respect to the surface of the photosensitive drum 2. When the photosensitive drum 2 rotates in the direction of the arrow (counterclockwise) in the figure, the tip of the brush portion must fall along the rotation direction. If the tip portion falls in the direction opposite to the rotation direction and comes into contact with the rotation of the photosensitive drum 2 in a counter state, the transfer residual toner on the photosensitive drum 2 may be scraped off. Further, when the brush portion falls down from the root of the raised portion, the density and contact pressure of the bristles abutting at the abutting portion with the photosensitive drum 2 become low, and the transfer residual toner cannot be sufficiently charged, A good image cannot be obtained.

Therefore, in this example, the bristling restraint rib of the brush portion and the inclined rib for surely inclining the brush portion along the rotation direction of the photosensitive drum 2 are provided in the entire longitudinal direction.

The hair fall regulating rib 11a2 is provided on the brush base 11a.
Is provided on the downstream side of the transfer residual toner uniformizing means 3g, which is a brush member, in the direction of rotation of the photosensitive drum, and when the transfer residual toner uniformizing means 3g is tilted as the photosensitive drum 2 rotates, from the root of the raised portion. I keep it from falling.

In the transfer residual toner equalizing means 3g of this example, the length of the brush bristles is 5 mm, and 1 to 1 from the root of the brush raising portion.
The hair fall restriction rib 11a2 is used to suppress the portion up to 2 mm, so that the contact state (contact density / contact pressure) of the brush tip portion of the transfer residual toner equalizing means 3g with the photosensitive drum 2 is kept constant.

The inclined rib 11a1 is provided on the upstream side of the transfer residual toner uniformizing means 3g in the photosensitive drum rotation direction, and has a rib height such that a portion 1 to 2 mm from the root of the brush raising portion enters (cuts into) the brush. Then, the transfer residual toner uniformizing means 3g is forcibly tilted in one direction (photosensitive drum rotation direction) in the entire longitudinal direction.

Further, regarding the toner charging control means 3h, similarly to the above, the inclined ribs 11a3 and the hair collapse regulating ribs 11 are formed.
b1 is provided.

As a result, when the brush unit 3j and the photosensitive drum 2 are assembled, the transfer residual toner equalizing means 3g and the toner charge amount controlling means 3 are provided on the upstream side as shown in FIG.
It is prevented that the brush tip of h comes into contact with the photosensitive drum 2 in a state of being inclined with respect to the rotational direction of the photosensitive drum 2 and comes into contact with the photosensitive drum 2 in a counter state with respect to the rotational direction of the photosensitive drum 2. By controlling the collapse of the control means 3h, the brush contact state of the transfer residual toner equalizing means 3g and the toner charge amount control means 3h with respect to the photosensitive drum 2 is maintained in a predetermined state.

[Second Embodiment] Next, a second embodiment of the charging means will be described. FIG. 10 is a schematic sectional view of a brush unit of the charging means according to the second embodiment, and FIG. 11 is a schematic sectional view of the charging means according to the second embodiment.

In this example, the flexible bristle member is used for the brush bristling regulation and the inclination of the first embodiment.

The flexible sheet has a sheet shape such as urethane and PET resin. In the hair collapse regulation, one end side of the hair collapse regulation sheet 20a is fixed by adhering it to the brush base 11a, and the leading end side (free end side) of the transfer residual toner equalizing means 3
It is close to the side surface of the brush part g. Inclination is seat 20b
One end side of is fixed to the brush base 11a, and the tip side (free end side) is bent and pressed against the side surface of the brush portion of the transfer residual toner equalizing means 3g. The tip of the brush portion of the transfer residual toner equalizing means 3g is tilted in the direction of rotation of the photosensitive drum by the contact pressure of the sheet 20b.

Further, as for the toner charging control means 3h, the sheet 21b and the hair collapse regulating sheet 21a are also similarly to the above.
Is provided.

When the brush unit 3j and the photosensitive drum 2 are assembled, the sheet 20b on the upstream side, as shown in FIG.
21b prevents the transfer residual toner equalizing means 3g and the toner charge amount control means 3h from abutting in a state of being inclined in the rotational direction of the photosensitive drum 2 and abutting in a counter state with respect to the rotational direction of the photosensitive drum. The transfer residual toner equalizing means 3g and the toner charge amount control means 3h are inclined and contact the tips of the adjacent hair collapse regulating sheets 21a and 21b to regulate the hair collapse. The brush contact state of the charging unit 3g and the toner charge amount control unit 3h is maintained in a predetermined state.

[Third Embodiment] Next, a third embodiment will be described.
FIG. 12 is a schematic cross-sectional view of the brush unit of the charging means according to the third embodiment, and FIG. 13 is a schematic cross-sectional view of the charging means according to the third embodiment.

This example is a combination of the first and second embodiments in order to more reliably control the fall of the brush hair and the inclination.

The hair fall restricting rib 11a2 is provided on the brush base 11a.
Is provided on the downstream side of the transfer residual toner uniformizing means 3g, which is a brush member, in the direction of rotation of the photosensitive drum, and when the transfer residual toner uniformizing means 3g is tilted as the photosensitive drum 2 rotates, from the root of the raised portion. I keep it from falling.

The inclined rib 11a1 is provided on the upstream side of the transfer residual toner equalizing means in the photosensitive drum rotation direction, and has a rib height such that a portion 1 to 2 mm from the root of the brush raising portion enters (cuts into) the brush. The transfer residual toner equalizing means 3g is forcibly tilted in one direction (photosensitive drum rotation direction) in the entire longitudinal direction.

The seat 20b has an inclined rib 11a1 at one end thereof.
The end of the brush is pressed against the side surface of the brush, and the brush is tilted in the rotational direction of the photosensitive drum by the contact pressure of the sheet 20b.

Also, regarding the toner charging control means 3h, similarly to the above, the inclined ribs 11a3 and the hair collapse regulating ribs 11 are formed.
b1 and the sheet 21b are provided.

As a result, when the brush unit 3j and the photosensitive drum 2 are assembled, as shown in FIG. 12, the brush tips of the transfer residual toner equalizing means 3g and the toner charge amount controlling means 3h are in the rotational direction of the photosensitive drum 2 on the upstream side. Abutting in a tilted state prevents contact in a counter state with respect to the rotation direction of the photosensitive drum, and on the downstream side, the transfer residual toner equalizing means 3g and the toner charge amount control means 3h regulate the hair collapse, The brush contact state of the transfer residual toner uniformizing means 3g and the toner charge amount control means 3h with respect to the drum 2 is maintained in a predetermined state.

That is, as in the above example, ribs and sheets are provided on the upstream side of the brush member in the moving direction of the image carrier so as to be pressed against the brush member and inclined to the moving direction of the image carrier. Further, a rib is provided on the downstream side of the brush in the moving direction of the image carrier, the rib being close to the brush and restricting the collapse of the bristles of the brush. As a result, in the cleanerless-type image forming apparatus, the contact state of the brush of the charging device having the plate-shaped brush member that is disposed so as to face the image carrier and the tip of which is in contact with the surface of the image carrier is stabilized. It is possible to prevent charging failure and collection failure due to toner fusion to the image bearing member, toner contamination of the charging roller, and toner drop on the image bearing member.

[Others] 1) The charging device according to the present invention is not limited to the charging means such as the image carrier or the developer of the process cartridge or the image forming apparatus in the embodiment, and is widely arranged to face the charged body.
It is effective as an improvement device for a charging device having a plate-shaped brush member whose tip portion is in contact with the surface of the body to be charged.

2) The image carrier of the process cartridge or the image forming apparatus is not limited to the electrophotographic photosensitive member, but may be an electrostatic recording dielectric or the like in the electrostatic recording process.

3) The member to be charged (image bearing member) is not limited to the drum type rotation, and may be an endless belt member that is rotationally driven, a web-shaped member that is driven and moved, or a plate-shaped member.

[0179]

As described above, according to the present invention, there is provided a charging device having a plate-like brush member which is arranged so as to face a member to be charged and whose tip portion is in contact with the surface of the member to be charged. By contacting the upstream side of the moving direction of the charged body with the rib and the flexible sheet to incline in the moving direction of the charged body, it is possible to prevent counter-contact with the brush member moving direction of the charged body, For example, in a cleanerless system, a charging device provided with a brush-shaped member such as a developer charge amount control unit, a process cartridge, and an electrophotographic image forming apparatus, the residual developer on the image carrier is brushed. Scratch is prevented.

The ribs and the flexible sheet are brought into contact with the downstream side of the brush member in the moving direction of the charged body to regulate the hair collapse in the moving direction of the charged body. The contact state (contact pressure, contact density) with respect to is stably maintained, for example, a cleanerless system, a charging device provided with a brush-shaped member such as a developer charge amount control unit, a process cartridge, and an electrophotographic device. In the image forming apparatus, the charge is favorably applied to the residual developer.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an image forming apparatus main body according to an exemplary embodiment.

FIG. 2 is a sectional view of a process cartridge and a toner supply container according to an exemplary embodiment.

FIG. 3 is a schematic perspective view of an image forming apparatus main body according to an exemplary embodiment.

FIG. 4 is a longitudinal sectional view of a process cartridge according to an exemplary embodiment.

FIG. 5 is a longitudinal sectional view of the toner supply container according to the exemplary embodiment.

FIG. 6 is a schematic perspective view of a charging unit that employs a cleanerless system according to an exemplary embodiment.

FIG. 7 is a schematic cross-sectional view of charging means according to the first embodiment.

FIG. 8 is a schematic front view of the charging unit according to the first embodiment.

FIG. 9 is a schematic sectional view of the brush unit of the charging means according to the first embodiment.

FIG. 10 is a schematic cross-sectional view of a brush unit of charging means according to the second embodiment.

FIG. 11 is a schematic sectional view of a charging unit according to a second embodiment.

FIG. 12 is a schematic cross-sectional view of the brush unit of the charging means according to the third embodiment.

FIG. 13 is a schematic sectional view of a charging unit according to a third embodiment.

[Explanation of symbols]

1Y, 1M, 1C, 1K: process cartridge 1b: replenishing opening, 2: photosensitive drum 2a: drum shaft, 2b: drum flange, 2c: bearing case, 2d: non-driving flange, 2e: bearing, 2
f: center hole, 2g: drive transmission part 3: charging device 3a: charging roller, 3b: core metal, 3c: charging roller cleaning member, 3d: pressing spring, 3e: cleaning film, 3f: support member, 3g: transfer residue Toner equalizing means, 3h: toner charge amount control means, 3j: brush unit, 3k: frame 4: developing device 4a: developing sleeve, 4a1: journal portion, 4
b: magnet roller, 4c: regulating blade, 4d:
Partition wall, 4eA, 4eB: stirring screw, 4f: developing container, 4g: sensor, 4h: developer storage section, 4
j: bearing, 4k: spacers 5Y, 5M, 5C, 5K: toner supply container 5a: screw, 5b: stirring plate, 5c: stirring shaft,
5d: bearing, 5e: drive coupling (concave), 5
f: discharge opening 5f1: discharge port cover 5f2: pressing member 5f3: discharge port shutter 5f5: opening 5f6: sealing members 11a, 11b: brush bases, 11a1, 11a3: inclined ribs, 11a2, 11b1: bristling restriction ribs, 12 :
Base frame, 13a, 13b, 13c, 13d:
Shaft, 14: Transmission arm member, 14a: Projection part 15: Coupling gear, 16: Reciprocating cam, 16
a: cam gear, 16b: cam, 16c: cam groove, 1
8: compression coil spring, 20a, 20b, 21a, 2
1b: Sheets 51Y, 51M, 51C, 51K: Exposure means, 51a:
Polygon mirror, 51b: Imaging lens, 51c: Reflecting mirror L: Laser light 52: Recording medium 53: Feeding means 53a: Feeding cassette, 53b: Feeding roller, 53
c: retard roller, 53d: feeding guide, 53e,
53f: conveyance roller, 53g: registration roller, 53
h, 53j: discharge roller 54: intermediate transfer unit 54a: intermediate transfer belt, 54b: drive roller, 5
4c: driven roller, 54d: secondary transfer roller, 54f
Y, 54fM, 54fC, 54fK: transfer charging roller,
54g: Secondary transfer counter roller 55: Transfer cleaning unit 55a: Cleaning blade, 55b: Feed screw 56: Fixing device 56a: Fixing roller, 56b: Pressure roller 57: Tray 58: Front door 59: Centering plates 60, 61 : Guide rails 62a, 62b: Drive couplings 63, 64: Support pin 65: Rear plate 66: Centering shafts 67, 68: Convex part 100: Device body a: Charging part, b: Exposure part, c: Development part, d: transfer part

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenji Matsuda             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F-term (reference) 2H071 BA05 BA13 BA27 DA06 DA15                 2H134 JA05 JA11 MA02 MA09 MA11                       MA19

Claims (68)

[Claims] 1. A charging device having a plate-shaped brush member, which is disposed so as to face a member to be charged and whose tip portion is in contact with the surface of the member to be charged, in a width direction of the brush member, downstream in the moving direction of the member to be charged. 2. A charging device, wherein a brush collapse regulating member is provided on a side of the brush member for regulating the brush member from collapsing from a brush root portion of the brush member in a moving direction due to movement of the charged body. 2. The bristling restraint member is a rib-shaped member that is close to the downstream side in the widthwise direction of the brush member in the moving direction of the charged body and is continuously long in the longitudinal direction of the brush member. The charging device according to claim 1. 3. The charging device according to claim 2, wherein the rib-shaped member is longer than the brush member. 4. The bristling restraint member is a flexible sheet, and the tip end portion of the flexible sheet on the free end side is close to the downstream side surface of the brush member in the moving direction of the charged body, The charging device according to claim 1, which is a flexible sheet that is continuously long in the longitudinal direction of the brush member. 5. The charging device according to claim 4, wherein the flexible sheet is longer than the brush member. 6. The charging device according to claim 1, wherein the brush member is a charging unit having conductivity and uniformly charging the surface of the body to be charged. 7. The charging device according to claim 1, wherein the member to be charged is an image bearing member that rotates such as an electrophotographic photosensitive member. 8. The developing member formed on the image carrier, wherein the brush member has conductivity and is upstream of the charging means acting on the image carrier, which is a member to be charged, in the moving direction of the image carrier. It is a developer charge amount control unit that is located on the downstream side of the transfer unit that transfers the agent image to the transfer material and that charges the residual developer remaining on the image carrier after the transfer process to a predetermined polarity. The charging device according to claim 1, wherein the charging device is a charging device. 9. The developing member formed on the image carrier, wherein the brush member has conductivity and is upstream of the charging means acting on the image carrier, which is a member to be charged, in the moving direction of the image carrier. The residual developer image uniformizing means is located downstream of the transfer means for transferring the developer image to the transfer material and uniformizes the residual developer image remaining on the image carrier after the transfer step. The charging device according to any one of claims 1 to 7. 10. The charging device according to claim 8, wherein the image bearing member is a rotating electrophotographic photosensitive member. 11. A charging device comprising a plate-shaped brush member, which is disposed so as to face a member to be charged and whose tip portion is in contact with the surface of the member to be charged, in the width direction of the brush member, the upstream side in the moving direction of the member to be charged. A charging device, characterized in that an inclining member for inclining the brush member in the moving direction of the charged body is provided on the side. 12. The inclining member has a tip portion in pressure contact with an upstream side surface in the widthwise direction of the brush member in the moving direction of the charged body to incline the brush member in the moving direction of the charged body. The charging device according to claim 11, wherein the charging device is a rib-shaped member that is continuously long in the longitudinal direction. 13. The charging device according to claim 12, wherein the rib-shaped member is longer than the brush member. 14. The inclined member is a flexible sheet,
The free end side tip portion of the flexible sheet is in pressure contact with the upstream side surface of the brush member in the width direction of the brush member to incline the brush member in the charge member moving direction. The charging device according to claim 11, wherein the charging device is a flexible sheet that is continuously long in a direction. 15. The charging device according to claim 14, wherein the flexible sheet is longer than the brush member. 16. The tilt member tilts the brush member in the rotational direction of the charged member by contacting the tip end thereof with the upstream side surface of the brush member in the width direction of the brush member in the moving direction of the charged member. A continuously long rib-shaped member,
Further, one end side is fixed to the rib-shaped member, the free end side tip portion is pressed against the upstream side surface in the rotation direction of the charged body in the width direction of the brush member to incline the brush member in the rotational direction of the charged body, The charging device according to claim 11, comprising a flexible sheet member that is continuously long in the longitudinal direction of the brush member. 17. The charging device according to claim 16, wherein the rib-shaped member is longer than the brush member, and the flexible sheet member is longer than the brush member. 18. The charging device according to claim 11, wherein the brush member is a charging unit which has conductivity and uniformly charges the surface of the body to be charged. 19. The charging device according to claim 11, wherein the member to be charged is an image bearing member that rotates such as an electrophotographic photosensitive member. 20. The developing member formed on the image carrier, wherein the brush member has conductivity and is upstream of the charging means acting on the image carrier, which is a member to be charged, in the moving direction of the image carrier. It is a developer charge amount control unit that is located on the downstream side of the transfer unit that transfers the agent image to the transfer material and that charges the residual developer remaining on the image carrier after the transfer process to a predetermined polarity. 20. The charging device according to claim 11, wherein the charging device is a charging device. 21. The developing member formed on the image carrier, wherein the brush member has conductivity and is upstream of the charging means acting on the image carrier, which is a member to be charged, in the moving direction of the image carrier. The residual developer image uniformizing means is located downstream of the transfer means for transferring the developer image to the transfer material and uniformizes the residual developer image remaining on the image carrier after the transfer step. 20. The charging device according to claim 11, wherein 22. The charging device according to claim 20, wherein the image bearing member is a rotating electrophotographic photosensitive member. 23. In a charging device having a plate-like brush member which is arranged so as to face a member to be charged and whose tip portion is in contact with the surface of the member to be charged, in the width direction of the brush member, the charging member is downstream in the moving direction of the member to be charged. To the side, the brush member for regulating the brush member in the moving direction by the movement of the charged member in the moving direction from the brush root portion of the brush member, and the charged member moving direction upstream in the width direction of the brush member And a tilting member for tilting the brush member in the moving direction of the body to be charged. 24. The bristling restraint member is a rib-shaped member that is close to the downstream side in the moving direction of the charged body in the width direction of the brush member and is continuously long in the longitudinal direction of the brush member. The charging device according to claim 23. 25. The charging device according to claim 24, wherein the rib-shaped member is longer than the brush member. 26. The hair collapse regulating member is a flexible sheet, and a free end side tip portion of the flexible sheet is close to a downstream side surface in the moving direction of the charged body in the width direction of the brush member, The charging device according to claim 23, which is a flexible sheet that is continuously long in the longitudinal direction of the brush member. 27. The charging device according to claim 26, wherein the flexible sheet is longer than the brush member. 28. The inclination member has a tip portion in pressure contact with an upstream side surface of the brush member in the width direction of the brush member in the moving direction of the charged body to incline the brush member in the moving direction of the charged body. The charging device according to claim 23, which is a rib-shaped member that is continuously long in the longitudinal direction. 29. The charging device according to claim 28, wherein the rib-shaped member is longer than the brush member. 30. The tilting member is a flexible sheet,
The free end side tip portion of the flexible sheet is in pressure contact with the upstream side surface of the brush member in the width direction of the brush member to incline the brush member in the charge member moving direction. 24. The charging device according to claim 23, wherein the charging device is a flexible sheet that is continuously long in a direction. 31. The charging device according to claim 30, wherein the flexible sheet is longer than the brush member. 32. The tilt member tilts the brush member in the moving direction of the charged body by contacting the tip end thereof with the upstream side surface of the brush member in the width direction of the brush member in the moving direction of the charged body. A continuously long rib-shaped member,
Further, one end side is fixed to the rib-shaped member, the free end side tip portion is pressed against the upstream side surface in the width direction of the brush member in the moving direction of the charged body, and the brush member is inclined in the moving direction of the charged body. 24. The charging device according to claim 23, comprising a flexible sheet member that is continuously long in the longitudinal direction of the brush member. 33. The charging device according to claim 32, wherein the rib-shaped member is longer than the brush member, and the flexible sheet member is longer than the brush member. 34. The charging device according to claim 23, wherein the brush member is a charging unit having conductivity and uniformly charging the surface of the body to be charged. 35. The charging device according to claim 23, wherein the member to be charged is an image bearing member that rotates such as an electrophotographic photosensitive member. 36. The developing member formed on the image carrier, wherein the brush member has conductivity and is upstream of the charging means acting on the image carrier, which is a member to be charged, in the moving direction of the image carrier. A developer charge amount control unit that is located on the downstream side of the transfer unit that transfers the developer image to the transfer material and that charges the residual developer remaining on the electrophotographic photosensitive member after the transfer process to a predetermined polarity. 36. The charging device according to claim 23. 37. The developing member formed on the image carrier, wherein the brush member has conductivity and is upstream of the charging means acting on the image carrier, which is the member to be charged, in the moving direction of the image carrier. It is a residual developer image homogenizing means which is located on the downstream side of the transfer means for transferring the agent image to the transfer material and which homogenizes the residual developer image remaining on the image bearing optical body after the transfer step. The charging device according to claim 23. 38. The charging device according to claim 36, wherein the image bearing member is a rotating electrophotographic photosensitive member. 39. An image forming apparatus, comprising: at least an image carrier; and a charging unit having a plate-like brush member that is disposed so as to face the image carrier and has a tip portion in contact with the surface of the image carrier. In a process cartridge that is attached to and detached from the apparatus main body, an inclination member for inclining the brush member in the image carrier moving direction is provided on the upstream side in the width direction of the brush member in the image carrier moving direction. Process cartridge. 40. The inclination member has a tip portion in pressure contact with an upstream side surface in the image carrier moving direction in the width direction of the brush member to incline the brush member in the image carrier moving direction. 40. The process cartridge according to claim 39, which is a rib-shaped member that is continuously long in the longitudinal direction. 41. The process cartridge according to claim 40, wherein the rib-shaped member is longer than the brush member. 42. The tilting member is a flexible sheet,
The free end side tip of the flexible sheet is in pressure contact with the upstream side surface of the brush member in the width direction of the image carrier so as to incline the brush member in the image carrier moving direction. 40. The process cartridge according to claim 39, which is a flexible sheet that is continuously long in a direction. 43. The process cartridge according to claim 42, wherein the flexible sheet is longer than the brush member. 44. The slanting member has a tip portion in pressure contact with an upstream side surface in the width direction of the brush member in the image carrier moving direction to incline the brush member in the image carrier moving direction, and thereby the longitudinal direction of the brush member. A continuously long rib-shaped member,
Further, one end side is fixed to the rib-shaped member, the free end side tip portion is in pressure contact with the upstream side surface in the image carrier moving direction in the width direction of the brush member to incline the brush member in the image carrier moving direction, 40. The process cartridge according to claim 39, comprising a flexible sheet member which is continuously long in the longitudinal direction of the brush member. 45. The process cartridge according to claim 44, wherein the rib-shaped member is longer than the brush member, and the flexible sheet member is longer than the brush member. 46. The process cartridge according to claim 39, wherein the brush member is a charging unit having conductivity and uniformly charging the surface of the image carrier. 47. The brush member has conductivity, and transfers the developer image formed on the image carrier upstream of the charging means acting on the image carrier in the moving direction of the image carrier. It is a developer charge amount control means which is located on the downstream side of the transfer means for transferring to the material and charges the residual developer remaining on the image carrier after the transfer step to a predetermined polarity. Item 44. The process cartridge according to any one of items 39 to 45. 48. The brush member has conductivity, and transfers the developer image formed on the image carrier upstream from the charging means acting on the image carrier in the moving direction of the image carrier. 40. The residual developer image homogenizing means, which is located on the downstream side of the transfer means for transferring to the material and uniformizes the residual developer image remaining on the image carrier after the transfer step. 45. The process cartridge according to any one of 1 to 45. 49. The process cartridge according to claim 39, further comprising a developing device for visualizing an electrostatic latent image on the surface of the image carrier into a developer image. 50. The process cartridge according to claim 39, wherein the image bearing member is a rotating electrophotographic photosensitive member. 51. An image forming apparatus, comprising: at least an image carrier; and a charging unit having a plate-like brush member which is arranged to face the image carrier and has a front end abutting the surface of the image carrier. In the process cartridge that is attached to and detached from the apparatus main body, the brush member moves in the width direction of the brush member toward the downstream side in the moving direction of the image carrier from the brush root portion of the brush member in the moving direction by the movement of the image carrier. A hair fall restricting member that restricts falling, and an inclination member that inclines the brush member in the image carrier moving direction on the upstream side in the image carrier moving direction in the width direction of the brush member. Process cartridge. 52. The bristling restraint member is a rib-shaped member that is close to the downstream side in the moving direction of the image carrier in the width direction of the brush member and is continuously long in the longitudinal direction of the brush member. 52. The process cartridge according to claim 51. 53. The process cartridge according to claim 52, wherein the rib-shaped member is longer than the brush member. 54. The bristling restraint member is a flexible sheet, and the free end side tip portion of the flexible sheet is close to the downstream side surface in the image carrier moving direction in the width direction of the brush member, The process cartridge according to claim 51, which is a flexible sheet that is continuously long in the longitudinal direction of the brush member. 55. The process cartridge according to claim 54, wherein the flexible sheet is longer than the brush member. 56. The slanting member has a tip portion in pressure contact with an upstream side surface in the width direction of the brush member in the image carrier moving direction to incline the brush member in the image carrier moving direction. 52. The process cartridge according to claim 51, which is a rib-shaped member that is continuously long in the longitudinal direction. 57. The process cartridge according to claim 56, wherein the rib-shaped member is longer than the brush member. 58. The tilting member is a flexible sheet,
The free end side tip of the flexible sheet is in pressure contact with the upstream side surface of the brush member in the width direction of the image carrier so as to incline the brush member in the image carrier moving direction. 52. The process cartridge according to claim 51, which is a flexible sheet that is continuously long in a direction. 59. The tilt member tilts the brush member in the moving direction of the image bearing member by contacting the tip end thereof with the upstream side surface in the moving direction of the brush bearing member in the width direction of the brush member so as to tilt in the longitudinal direction of the brush member. A continuously long rib-shaped member,
Further, one end side is fixed to the rib-shaped member, the free end side tip portion is in pressure contact with the upstream side surface in the image carrier moving direction in the width direction of the brush member to incline the brush member in the image carrier moving direction, 52. The process cartridge according to claim 51, comprising a flexible sheet member that is continuously long in the longitudinal direction of the brush member. 60. The process cartridge according to claim 59, wherein the rib-shaped member is longer than the brush member, and the flexible sheet member is longer than the brush member. 61. The process cartridge according to any one of claims 51 to 59, wherein the brush member is a charging unit having conductivity and uniformly charging the surface of the image carrier. 62. The brush member has conductivity, and transfers the developer image formed on the image carrier upstream from the charging means acting on the image carrier in the moving direction of the image carrier. It is a developer charge amount control means which is located on the downstream side of the transfer means for transferring to the material and charges the residual developer remaining on the image carrier after the transfer step to a predetermined polarity. Item 61. The process cartridge according to any one of items 51 to 60. 63. The brush member has conductivity, and transfers a developer image formed on the image carrier upstream from the charging means acting on the image carrier in the moving direction of the image carrier. 52. A residual developer image uniformizing means, which is located on the downstream side of the transfer means for transferring to a material and uniformizes the residual developer image remaining on the image carrier after the transfer step. 61. The process cartridge according to any one of 1 to 60. 64. The process cartridge according to claim 51, further comprising a developing device for visualizing an electrostatic latent image on the surface of the image carrier into a developer image. 65. The process cartridge according to claim 51, wherein the image carrier is a rotating electrophotographic photosensitive member. 66. An image forming apparatus comprising: an image carrier; and a charging device having a plate-shaped brush member, which is disposed so as to face the image carrier and has a tip portion in contact with the surface of the image carrier. An image forming apparatus, wherein the charging device is the charging device according to any one of claims 1 to 38. 67. A process cartridge detachable image forming apparatus, wherein the process cartridge is the process cartridge according to any one of claims 39 to 65. 68. At least an electrophotographic photosensitive member which is an image bearing member, and a developing device which visualizes an electrostatic latent image on the surface of the electrophotographic photosensitive member as a developer image as a process means which acts on the electrophotographic photosensitive member. A charging means having a plate-shaped brush member arranged toward the center of the electrophotographic photosensitive member and having a tip portion in contact with the surface of the electrophotographic photosensitive member. A brush collapse restricting member that restricts the brush member on the downstream side in the rotation direction of the electrophotographic photosensitive member in the width direction from rotating from the brush root portion of the brush member in the rotating direction of the electrophotographic photosensitive member, and the brush. An inclined member for inclining the brush member in the rotation direction of the electrophotographic photosensitive member is provided on the upstream side in the rotation direction of the electrophotographic photosensitive member in the width direction of the member. Mounting means for removably mounting the cartridge, mounting means for freely mounting the cartridge, driving means for driving the process cartridge, and transfer means for transferring the developer image formed on the image carrier to a recording medium. An image forming apparatus, comprising: and a conveying unit configured to convey the recording medium.