JP2002162826A - Developing device, developing cartridge, process cartridge and electrophotographic image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably obtain the electrified quantity of toner on a developing roller under various environments. SOLUTION: As for the developing device which is provided with the developing roller 12 for carrying developer, developing bearings 30 and 31 for holding the developing roller 12 so that the roller 12 may be freely rotated, and which is prepared for developing a latent image formed on a photoreceptor drum 1 by the developer, the device is provided with an electrifying roller 14 for applying a charge on the developer carried by the developing roller 12 by an applied voltage in contact with the developing roller 12, the voltage is applied on the electrifying roller 14 from the direction of the rotary axis of the developing roller 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device and a developing cartridge for developing a latent image formed on an electrophotographic photosensitive member when an image is formed by an electrophotographic method.
The present invention relates to a process cartridge and an electrophotographic image forming apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, as a configuration of an apparatus for forming an image by an electrophotographic method, a drum-shaped electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) uniformly charged by a charging device is selectively used. A latent image is formed by exposure, and the latent image is visualized with a developer (hereinafter, referred to as toner) by a developing device, and an image formed by transferring the toner image to a recording medium is recorded.

FIG. 12 shows an example of such a developing device.
Has been proposed and put to practical use. In this conventional developing device, a developing roller 120 as a developer carrier is placed in a developing container 120 containing a non-magnetic one-component toner.
2. A developing blade 116 as a developer regulating member and an application roller 119 as a developer application member are provided. Here, the application roller 119 is connected to the developing blade 116.
Roller 11 than the contact position of the developing roller 11
2 is arranged so as to be in contact with the developing roller 112 on the upstream side in the rotation direction, and supplies toner onto the developing roller 112 by rotating in the direction of R2 in the figure.

The toner supplied to the developing roller 112 is
As the developing roller 112 rotates, it is sent to a contact portion with the developing blade 116. Here, the toner on the developing roller 112 is formed into a uniform thin layer (toner coat) by the developing blade 116, and at the same time, charge is applied by friction with the developing blade 116.

A developing bias is applied to the developing roller 112, and the toner on the developing roller 112 moves in accordance with the electrostatic latent image formed on the photosensitive drum 101, and the toner on the photosensitive drum 101 It is visualized as an image.

[0006]

However, in a developing device using a non-magnetic toner, the charge amount of the toner on the developing roller is not sufficient depending on the environment (temperature, humidity, etc.) where the developing device is placed. It is likely to be stable and may adversely affect image quality. Conventionally, in order to reduce the influence of the environment, the developing bias value is adjusted according to the environment so that the image quality is constant.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to stably obtain a charge amount of toner on a developing roller even in various environments. .

[0008]

In order to achieve the above object, a representative configuration of the present invention is a developer carrying member for carrying a developer, and a holding member for rotatably holding the developer carrying member. A developing device that visualizes a latent image formed on the image carrier by the developer, the developing device being in contact with the developer carrier, and being carried on the developer carrier by an applied voltage. A developer charging means for applying a charge to the developer is provided, and a voltage is applied to the developer charging means from the rotation axis direction of the developer carrier.

In the above construction, the amount of charge on the developer carrier is made constant by the developer charging means irrespective of environmental conditions, and a power supply section for the developer charging means is provided in the longitudinal direction of the developing device. The cross-sectional shape of the developing device can be reduced.

Further, the developer charging means is constituted by a rotating member which is in contact with the outer peripheral surface of the developer carrying member, so that the thinned developer on the developer carrying member can be uniformly dispersed without being disturbed. Charging becomes possible.

Also, an elastic member having conductivity is provided so as to contact one end surface in the longitudinal direction of the rotation axis of the developer charging means, and the conductive elastic member is connected to the developer charging means through the elastic member. By applying the voltage, it is possible to reliably apply the voltage.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. However,
The dimensions, materials, shapes, relative arrangements, and the like of the components described in the following embodiments should be appropriately changed depending on the configuration of the apparatus to which the present invention is applied and various conditions, and in particular, Unless otherwise described, the scope of the present invention is not intended to be limited to them.

[First Embodiment] A developing device (developing cartridge), a process cartridge, and an image forming apparatus using the same according to an embodiment of the present invention will be described.

In the following description, the longitudinal direction is a direction substantially perpendicular to the recording material conveyance direction and substantially parallel to the surface of the recording material.

First, a schematic configuration of the image forming apparatus according to the present embodiment will be described. FIG. 1 is a side view of a color laser beam printer which is an embodiment of an image forming apparatus for forming a color image by an electrophotographic method.

An electrophotographic photosensitive member as a drum-shaped image carrier rotating at a constant speed (hereinafter, referred to as a photosensitive drum)
1 is uniformly charged by the charging means 2. Then, the photosensitive drum 1 is irradiated with laser light corresponding to the image information from the exposure means 3 to form an electrostatic latent image, and the latent image is formed into four developing cartridges Dm, Dc, Dy, and Db (collectively D (Development device).

The color image is transferred from the feeding section to the conveying means 5.
Recording material P (for example, recording paper, OHP
(A sheet or the like) by the transfer means 6. And
The recording material P is conveyed to the fixing unit 7 to fix the color image, and is discharged to the discharge unit 8 on the upper surface of the apparatus.

Next, the configuration of each section will be specifically described.

The photosensitive drum 1 serves as a cleaning unit U as a process cartridge for removing toner remaining on the photosensitive drum 1 after transferring an image of a developer (hereinafter, referred to as toner) to the intermediate transfer unit 4. Of the cleaning means 9 is integrally formed with the container-shaped frame 9a.

The cleaning unit U is removably mounted on the main body 100 of the image forming apparatus.
The user can replace the photosensitive drum 1 according to the life thereof.

The photosensitive drum 1 is formed by coating an organic photoconductive layer on the outside of an aluminum cylinder having a diameter of about 50 mm, and is rotatable around a container-like frame 9a of a cleaning means 9 which also serves as a holder for the photosensitive drum 1. It is supported by.

Around the photosensitive drum 1, a cleaning blade 9b for scraping and removing the toner remaining on the photosensitive drum 1 and a charging means 2 are provided.

Therefore, in this embodiment, the photosensitive drum 1, the cleaning means 9, and the charging means 2 constitute a cleaning unit U as a process cartridge which can be integrally attached to and detached from the apparatus main body 100.

The photosensitive drum 1 rotates counterclockwise in FIG. 1 according to an image forming operation by transmitting a driving force of a driving motor (not shown).

The charging means 2 according to the present embodiment uses a so-called contact charging method, and applies a voltage to a conductive roller serving as a charging member which rotates in contact with the surface of the photosensitive drum 1. Thus, the surface of the photosensitive drum 1 is uniformly charged.

When an image signal is given to a laser diode (not shown), the exposure means 3 for exposing the charged photosensitive drum 1 irradiates the polygon mirror 3a with image light corresponding to the image signal. .

The polygon mirror 3a is rotated at high speed by a scanner motor 3b, and selects the surface of the photosensitive drum 1 on which the image light reflected by the polygon mirror 3a rotates at a constant speed via the imaging lens 3c and the reflection mirror 3d. Exposure to form an electrostatic latent image.

The latent image is stored in a developing cartridge (developing device).
D is developed for each color. The configuration of the developing cartridge D will be described later.

The toner image developed by the developing cartridge D is transferred to the intermediate transfer unit 4. The intermediate transfer unit 4 as a second image carrier is a photosensitive drum 1
, A plurality of toner images that are sequentially primary-transferred and superimposed sequentially are collectively secondary-transferred onto the recording material P.

The intermediate transfer unit 4 has an intermediate transfer belt 4a running in the direction of arrow R4. The intermediate transfer belt 4a of the present embodiment is a belt having a circumference of about 440 mm, and is stretched over three rollers: a driving roller 4b, a secondary transfer facing roller 4c, and a driven roller 4d.

There is provided a pressing roller 4j which retreats so as to take a position where the intermediate transfer belt 4a is pressed against the photosensitive drum 1 close to the driven roller 4d and a position where the intermediate transfer belt 4a is separated from the photosensitive drum 1.

The intermediate transfer belt 4a runs in the direction of arrow R4 by the rotation of the driving roller 4b. Further, a cleaning unit 4e is provided at a predetermined position outside the intermediate transfer belt 4a so as to be able to contact and separate from the surface of the intermediate transfer belt 4a. Remove the toner.

The cleaning unit 4e brings the charging roller 4f into contact with the intermediate transfer belt 4a to give the toner a charge opposite to that at the time of transfer. The toner to which the opposite charge has been applied is electrostatically attached to the photosensitive drum 1 and then collected by a cleaning unit 9 for the photosensitive drum 1 described later.

The toner remaining on the surface of the photosensitive drum 1 after transferring the toner image to the intermediate transfer belt 4a is removed by the cleaning means 9. That is, the toner is scraped off by the cleaning blade 9b as a cleaning member that has come into contact with the surface of the photosensitive drum 1, and is stored in the removed toner container 9c. The removed toner container 9c is formed of a cleaning frame 9a.

The amount of the removed toner stored in the removed toner container 9c is such that the removed toner container 9c is not filled earlier than the life of the photosensitive drum 1. When the cleaning unit U is replaced when the life of the photosensitive drum 1 has expired, the cleaning process is integrally performed.

The transfer means 6 for transferring the toner image multiplex-transferred to the intermediate transfer unit 4 onto the recording material P has a transfer roller as a transfer member in the present embodiment. Is wound with a medium-resistance foam elastic body, and is provided so as to be movable in the vertical direction in FIG.

While the transfer roller 6 is forming a four-color toner image on the intermediate transfer unit 4, that is, while the intermediate transfer unit 4 is rotated a plurality of times, the transfer roller 6 does not disturb the toner image as shown in FIG. As shown by the solid line, it is located below and separated from the intermediate transfer unit 4.

Then, after the toner image is multiplex-transferred onto the intermediate transfer unit 4 to form a color toner image, the transfer roller 6 is moved by a cam (not shown) in accordance with the timing of transferring the color toner image onto the recording material P. FIG.
Move to the upper position as shown by the one-dot chain line.

As a result, the transfer roller 6 is pressed against the intermediate transfer unit 4 via the recording material P with a predetermined pressure.
At the same time, a bias voltage is applied to the transfer roller 6,
The toner image on the intermediate transfer unit 4 is transferred to the recording material P.

The conveying means 5 for conveying the recording material P includes, for example, as shown in FIG. 1, a paper feed cassette 5a containing a plurality of recording materials P, a pickup roller 5b, a feed roller 5c1, and a double feed prevention. Roller 5c2, transport roller pair 5d, registration roller pair 5e, discharge roller pair 5f
And a transport guide 5g.

At the time of image formation, the pickup roller 5b is driven and rotated in accordance with the image forming operation, and separates and feeds the recording materials P in the sheet cassette 5a one by one. Then, the recording material P sent out from the paper feed cassette 5a is transported by the transport guide 5
g, and reaches the registration roller pair 5e via the conveyance roller pair 5d.

During the image forming operation, the registration roller pair 5e
Is a non-rotational operation that causes the recording material P to stand still,
Is carried out in a predetermined sequence, the image is transferred to the intermediate transfer unit 4 in a predetermined sequence, the image in the next transfer step is aligned with the recording material P, and the color toner image is transferred by the transfer means described above. Is done.

Recording material P on which color toner image has been transferred
Is transported to the fixing means 7 to fix the toner image.
The fixing means 7 includes a fixing roller 7a for applying heat to the recording material P and a pressure roller 7b for pressing the recording material P against the fixing roller 7a. Both rollers 7a and 7b are hollow rollers. Are each driven to rotate with a heater inside. Then, the toner image is fixed on the recording material P by being conveyed while applying heat and pressure to the recording material P.

Then, the recording material P on which the toner has been fixed is discharged by a discharge roller pair 5f constituting the conveying means 5 to a discharge section 8f.
Is discharged to

Next, the structure of a developing cartridge (developing device) for developing a latent image formed on the photosensitive drum 1 will be described.

This image forming apparatus has four developing cartridges D (Dm, Dc, Dy, Db) for enabling development of each color of magenta, cyan, yellow, and black in order to form a full-color image. . As shown in FIG. 1, the developing cartridge D is detachably mounted on a rotary unit 11 that rotates about a shaft 10.

During image formation, each developing cartridge D is rotated about the shaft 10 while being held by the rotary unit 11. Then, the developing cartridge D containing the predetermined color toner stops at a position facing the photosensitive drum 1. Further, after a developing roller described later is positioned with respect to the photosensitive drum 1, toner is supplied corresponding to the electrostatic latent image on the photosensitive drum 1 to develop the latent image.

At the time of forming a color image, the rotary unit 11 rotates each time the intermediate transfer unit 4 rotates, and a magenta developing cartridge Dm containing magenta toner and a cyan developing cartridge Dc containing cyan toner. The developing process is performed in the order of the yellow developing cartridge Dy containing the yellow toner and the black developing cartridge Db containing the black toner.

As shown in FIG. 2 and FIG.
The cartridge frame denoted by reference numeral 0 is
a, toner container 20b, developing bearing 3 as a holding member
0, 31 and a side cover 32.

As shown in FIG. 2, the developing frame 20a and the toner container 20b are provided with flanges 21 and 22 provided along the longitudinal direction on both short sides of the developing frame 20a.
And the coupling surfaces 23 and 24 provided on the toner container 20b are coupled by means such as ultrasonic welding.

As shown in FIG. 3, developing bearings 30 and 31 are screwed to both ends of the developing frame 20a and the toner container 20b in the longitudinal direction, which are connected by the above-described method. It is screwed to 31. As a result, all the frames become an integral cartridge frame 20.

The developing frame 20a is a photosensitive drum 1
Developing roller 12 as a developer carrier for developing the latent image formed on the toner, a toner supply roller 19 for supplying toner to an outer peripheral portion of the developing roller 12, and a thin layer of toner to the developing roller 12. It has a developing blade 16 as a developer regulating member for coating, and a charging roller 14 as a rotating member as developer charging means.

Next, the attachment of the toner supply roller 19 and the developing blade 16 to the developing frame 20a will be described.

FIG. 4 shows the developing frame 20a on the opposite side (non-driving side) of the developing cartridge D from the apparatus main assembly. A notch 25 for incorporating the toner supply roller 19 is provided in the developing frame 20a.

The toner supply roller 19 is connected to the developing frame 2
The shaft 19 b (not shown) on the side (drive side) of the developing cartridge D receiving drive from the apparatus main assembly is connected to the developing frame 20.
After passing through a through hole (not shown) provided on the drive side a, the shaft 19a at the other end is dropped into the notch 25 of the developing frame 20a to be incorporated into the developing frame 20a.

Thereafter, in order to seal the notch 25 of the developing frame 20a, a bush 26 having a shape fitted to the notch 25 is attached. Further, a packing 27 for sealing the rotation direction of the shaft is attached to the shafts 19a and 19b of the toner supply roller 19.

Seal seat surfaces 28 and 29 are provided at both ends and the longitudinal direction of the opening 20c of the developing frame 20a. After the toner supply roller 19 is assembled, seal members 33 and 34 are attached to these seating surfaces to prevent toner leakage from the developing frame opening 20c. After attaching these seals, the base plate 57, the developing blade 16 and the pressing plate 58 are attached to the blade seating surfaces 20a1 and 20a2 as shown in FIGS.

FIG. 8 shows the developing bearing 30 on the non-driving side. The developing bearing 30 has a shape that covers the longitudinal end surface of the cartridge frame 20, and is provided with a mounting surface 35 with the developing frame 20 a.

On the mounting surface 35, the developing frame 20
a positioning holes 60a, 6
0b (see FIG. 4).
The developing frame 20a is fixed to the developing frame 20a by tightening small screws (not shown) through the outer holes 35c and 35d at positions corresponding to the female screws 60c and 60d of the developing frame 20a.

FIG. 6 shows the developing bearing 31 on the driving side. The developing bearing 31 on the driving side is positioned and fixed to the developing frame 20a in the same manner as the developing bearing 30 on the non-driving side.

As shown in FIG. 6 and FIG.
A shaft 31a for supporting the drive input member 51 and a shaft 31b for supporting an idler gear 53 meshing with a toner carrying gear 52 provided coaxially with the toner carrying member 13 are also provided.

In the drive-side developing bearing 31, the shafts 12b and 19b of the developing roller 12 and the toner supply roller 19 penetrate, and the end portions 12c and 1 of each roller are provided.
Drive gears 54 and 55 are attached to 9c, respectively. By attaching these drive input members and gears, a drive input is made to the developing cartridge D.

A method of attaching the developing roller 12 of the developing device and the charging roller 14 as a developer charging means, which are main parts of the present invention, will be described below.

As shown in FIG. 8, the developing bearing 30 includes a developing roller bearing 30a, a toner supply roller bearing 30b,
And a charging roller bearing 30c. The charging roller bearing portion 30c extends in a direction connecting the center of the charging roller 14 and the center of the developing roller 12 with a substantially U-shaped guide groove (in a direction in which the charging roller 14 urges the developing roller 12 through a curved portion from an open end. Guides the shaft 14a of the charging roller 14)
It has become.

FIG. 10 is a diagram showing a cross section taken along line AA of FIG. An electrode plate 61 for applying a voltage to the charging roller 14 is attached to a longitudinally outer side (one end) of the charging roller bearing 30c as a conductive elastic member that supplies power to the charging roller 14. ing. This electrode plate 61
Is made of a material such as a phosphor bronze plate or a stainless steel plate, and has a leaf spring shape.

The attachment of the developing roller 12 and the charging roller 14 to the developing frame 20a is performed in the following procedure. Here, a description will be given of the non-driving side, but a similar configuration is adopted on the driving side.

As shown in FIGS. 4 and 8, the side surface of the developing frame 20a is a mounting surface (seat surface) 60 for mounting the developing bearing 30, and a positioning hole (reference) for positioning with the developing bearing 30. Holes) 60a and 60b are provided. Here, the positioning hole 60a is a round hole, and the positioning hole 60b is a long hole long in a direction connecting the centers of both holes. The mounting surface 60 is provided with female screws 60c and 60d for fixing the developing bearing. Developing frame 2
When the developing bearings 30 and 31 are attached to the side surface of Oa,
Therefore, since the central axis of the developing roller 12 is determined, the both sides of the developing frame 20a are parallel to each other, and the components are arranged so as to be in a normal direction to a tangent line when the developing blade 16 and the developing roller 12 abut. Dimensions are controlled.

Toner supply roller 19, developing blade 1
6. On the developing frame 20a having the seals attached,
The developing roller 12 is placed at a predetermined position, and the developing bearings 30 (and 31) are attached from both sides in alignment with the positioning holes 60a and 60b, and at the same time, the developing roller 12 is connected to the bearing portion 30a.
To fit. The developing bearing 30 is mounted on the developing frame 20a.
At this point, fastening with screws is performed, and the developing roller 12 is rotatably attached to the developing frame 20a.

As shown in FIG. 9, the developing bearing 30 (and 3
When 1) is attached to the developing frame 20a,
The non-drive-side developing bearing 3 is provided at both ends of the developing frame 20a.
The bearing portion for the charging roller 14 is formed by the zero charging roller bearing portion 30c and the charging roller bearing portion 30c of the developing bearing 31 on the driving side. The charging roller 14 is assembled along the bearing portion formed in this manner until it comes into contact with the developing roller 12. At this time, as shown in FIG. 10, the position in the longitudinal direction is regulated by the driving side end surface 14c of the charging roller 14 and the charging roller bearing portion 30c of the driving side developing bearing 31, and the non-driving side end surface 14b is 61, the electrode plate 61 and the charging roller 14 are electrically connected in the longitudinal direction. Here, the electrode plate 61 is a power supply path from the apparatus main body, whereby power can be supplied from the apparatus main body to the charging roller 14.

The charging roller 14 is held at one end in the longitudinal direction by the electrode plate 61 (the non-driving side end surface 14).
By being pressed from b) toward the other end, the position in the longitudinal direction is regulated. As described above, the electrode plate 61 as the conductive elastic member also has a role of regulating the position of the charging roller 14 in the longitudinal direction.

In this embodiment, a torsion coil spring 56 is provided to further urge the charging roller 14 toward the developing roller 12. As shown in FIG.
Is mounted on a boss 30d provided on the developing bearing 30, and then one end 56a is hung on the stopper 30e and the other end 56b is hung on the shaft 14a of the charging roller. As a result, the charging roller 14 is pressed against the developing roller 12, and the assembly of the charging roller 14 is completed.

Since the bearing 30a of the developing roller and the bearing 30c of the charging roller are provided on the same part (developing bearing 30), the center axis of the developing roller 12 is shifted from the center axis of the charging roller 14. Is less likely to occur. Further, the charging roller bearing (guide groove) 30 of the developing bearing 30
The direction of the open end of c is changed at an angle α in FIG. 8 in the middle thereof, which not only enhances the workability when the charging roller 14 is mounted, but also increases the charging roller 14 due to vibration during transportation. It has a role to prevent coming off.

As described above, according to the present embodiment, the power supply to the charging roller 14 is performed from the longitudinal direction of the charging roller 14 so that the power supply to the charging roller 14 can be reliably performed. As a result, a uniform charge amount can be given to the toner on the surface 12, and the assembling is easy and the cross-sectional direction of the apparatus can be reduced.

Further, the voltage is applied to the charging roller 14 through an electrode plate 61 which is an elastic member having conductivity, which is disposed so as to contact one end face in the longitudinal direction of the charging roller shaft 14a. By doing so, reliable voltage application becomes possible.

[Second Embodiment] Next, a second embodiment of the present invention will be described. FIG. 11 is an enlarged view of a main part showing a second embodiment of the present invention. Here, FIG.
FIG. 2 shows a cross section A and shows the periphery of a charging roller bearing.

In this embodiment, the electrode plate 62 is attached to the longitudinal end 30f of the charging roller bearing 30c of the developing bearing 30. Further, a portion having a smaller outer diameter than the sliding surface with the charging roller bearing 30c (small diameter portion 14d) is provided at the non-driving side end of the charging roller 14.

Further, in the configuration of the present embodiment, after the developing roller 12 and the developing bearing 30 are mounted on the developing frame 20a in the same manner as in the first embodiment, the small diameter portion 14d of the charging roller 14 is formed.
The unit to which the coil spring 63 is fitted is assembled along the charging roller bearing 30c.

At this time, the driving side end surface 1 of the charging roller 14
4c (see FIG. 10) and the charging roller bearing portion 30c of the drive-side developing bearing 31, the longitudinal direction is regulated, while the coil spring 63 is compressed and pressed against the electrode plate 62. Here, the coil spring 63 is made of a conductive elastic material such as a stainless steel wire, and the electrode plate 62 and the charging roller 14 are electrically connected in the longitudinal direction via the coil spring 63. The electrode plate 62 is a member that receives power supply from the apparatus main body, whereby the charging roller 14 is in a state in which power supply from the apparatus main body is possible.

Further, in the configuration of this embodiment, the torsion coil spring 56 is attached in the same manner as in the first embodiment, and the charging roller 14 is urged toward the developing roller 12 (see FIG. 9).

As described above, also according to the present embodiment,
As in the above-described first embodiment, power supply to the charging roller 14 can be reliably performed, a uniform charge amount can be given to the toner on the developing roller 12, and assembly can be performed easily. Can be reduced in cross-sectional direction.

An electrode plate 62 and a coil spring 63 which constitute the elastic member having conductivity are provided so as to apply a voltage to the charging roller 14 so as to contact one end face of the charging roller shaft 14a in the longitudinal direction. , It is possible to reliably apply a voltage. Needless to say, the electrode plate 62 may be a member having no elasticity.

[Other Embodiments] In the above embodiment,
The case where four detachable developing cartridges (developing devices) are used for the image forming apparatus main body has been exemplified, but the number of used is not limited, and may be appropriately set as needed.

In the above-described embodiment, the process cartridge is detachable from the image forming apparatus main body.
Although a process cartridge has been exemplified in which a photosensitive drum and a charging unit and a cleaning unit as process units acting on the photosensitive drum are illustrated, the invention is not limited to this. For example, in addition to the photosensitive drum, A process cartridge integrally including one of the charging unit and the cleaning unit, or a photosensitive drum and a developing device, and further including a charging unit and a cleaning unit.
It may be a process cartridge having any one unitarily.

Further, in the above-described embodiment, the configuration in which the developing cartridge including the developing device and the process cartridge including the photosensitive drum are detachable from the main body of the image forming apparatus is exemplified. However, the present invention is not limited to this. For example, an image forming apparatus in which each component such as a developing device is incorporated, or an image forming apparatus in which each component such as a developing device is detachable.

In the above-described embodiment, a printer is exemplified as an image forming apparatus. However, the present invention is not limited to this. For example, another image forming apparatus such as a copying machine or a facsimile apparatus, An image forming apparatus may be used in which a transfer conveyance belt is used as a body and toner images of respective colors are sequentially superimposed and transferred onto a transfer medium such as a recording sheet carried on the transfer conveyance belt. Similar effects can be obtained by applying the invention.

[0086]

As described above, according to the present invention,
By supplying power to the developer charging unit from the longitudinal direction of the developer charging unit, power can be reliably supplied to the developer charging unit, and uniform charging of the toner on the developer carrying member is achieved. In addition to being able to provide an amount, it is easy to assemble and the cross-sectional direction of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating a schematic configuration of an entire image forming apparatus.

FIG. 2 is a cross-sectional view illustrating a configuration of a frame of the developing cartridge.

FIG. 3 is a perspective view illustrating a configuration of a frame of the developing cartridge.

FIG. 4 is an exploded perspective view of a developing device (non-driving side).

FIG. 5 is an exploded perspective view of the developing device.

FIG. 6 is an exploded perspective view of a developing device (drive side).

FIG. 7 is a schematic sectional view of a developing device.

FIG. 8 is a perspective view of a non-driving side developing bearing of the developing device according to the first embodiment of the present invention.

FIG. 9 is a perspective view of the periphery of the non-driving side of the developing device according to the first embodiment of the present invention.

FIG. 10 is a sectional view of a main part of a charging roller unit of the developing device according to the first embodiment of the present invention;

FIG. 11 is an enlarged sectional view of a main part of a charging roller unit of a developing device according to a second embodiment of the present invention.

FIG. 12 is a sectional view showing a conventional developing device.

[Explanation of symbols]

 Dm, Dc, Dy, Db ... developing cartridge P ... recording material U ... cleaning unit 1 ... photosensitive drum 2 ... charging means 3 ... exposure means 3a ... polygon mirror 3b ... scanner motor 3c ... imaging lens 3d ... reflection mirror 4 ... Intermediate transfer unit 4a ... Intermediate transfer belt 4b ... Drive roller 4c ... Next transfer opposing roller 4d ... Driving roller 4e ... Cleaning unit 4f ... Charge roller 4j ... Pressing roller 5 ... Conveying means 5a ... Paper feeding cassette 5b ... Pickup roller 5c1 ... Supply Feed roller 5c2 Retard roller 5d Transport roller pair 5e Registration roller pair 5f Discharge roller pair 5g Transport guide 6 Transfer unit 7 Fixing unit 7a Fixing roller 7b Pressure roller 8 Discharge unit 9 Cleaning unit 9a ... Frame 9b ... Cleani Blade 9c ... removed toner container 10 ... shaft 11 ... rotary unit 12 ... developing roller 12b ... shaft 12c ... end 13 ... toner transport member 14 ... charging roller 14a ... shaft 14b ... non-drive side end surface 14c ... drive side end surface 14d ... small diameter Part 16: developing blade 19: toner supply rollers 19a, 19b: shaft 19c: end 20: cartridge frame 20a: developing frame 20a1, 20a2: blade seating surface 20b: toner container 20c: opening 21, 22, ... flanges 23, 24 ... Coupling surface 25 ... Notch 26 ... Bushing 27 ... Packing 28,29 ... Seal seat 30,31 ... Development bearing 30a ... Development roller bearing 30b ... Toner supply roller bearing 30c ... Charge roller bearing 30d ... Boss 30e ... Stopper 30f ... Longitudinal Direction end portions 31a, 31b ... shaft 32 ... side covers 33, 34 ... seal members 35 ... mounting surfaces 35a, 35b ... positioning bosses 35c, 35d ... outer holes 51 ... drive input members 52 ... toner transport gears 53 ... idler gears 54, 55 ... gear 56 ... coil springs 56a, 56b ... one end 57 ... base plate 58 ... holding plate 60 ... mounting surface 60a, 60b ... positioning holes 60c, 60d ... female screws 61, 62 ... electrode plate 63 ... coil spring 100 ... image forming apparatus body

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Koji Hashimoto 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H071 DA08 DA15 DA34 2H077 AD02 AD13 AE10 BA08 EA15

Claims (9)

[Claims] 1. A developer carrying member for carrying a developer, and a holding member for rotatably holding the developer carrying member,
In a developing device for visualizing a latent image formed on an image carrier by the developer, the developer is brought into contact with the developer carrier, and the developer carried on the developer carrier by an applied voltage. A developing device comprising: a developer charging means for applying a charge; and a voltage is applied to the developer charging means from the direction of the rotation axis of the developer carrier. 2. The developing device according to claim 1, wherein the developer charging unit is a rotating member that contacts an outer peripheral surface of the developer carrier. 3. An electroconductive elastic member is provided so as to be in contact with one end face in the longitudinal direction of a rotation axis of the developer charging means, and the developer is supplied to the developer charging means through the electroconductive elastic member. 2. A voltage application is performed.
3. The developing device according to claim 1. 4. The developing device according to claim 3, wherein the elastic member having conductivity also serves to regulate a position of the developer charging unit in a longitudinal direction. 5. A developing cartridge comprising at least the developing device according to claim 1, wherein the developing cartridge is detachable from an image forming apparatus. 6. An electrophotographic photosensitive member and at least one of processing means acting on the electrophotographic photosensitive member.
A process cartridge comprising the developing device according to any one of the preceding claims, and detachable from an image forming apparatus. 7. An electrophotographic photosensitive member, and at least one of processing means acting on the electrophotographic photosensitive member.
An electrophotographic image forming apparatus, comprising the developing device according to any one of the preceding claims. 8. An electrophotographic image forming apparatus comprising the developing cartridge according to claim 5. 9. An electrophotographic image forming apparatus comprising the process cartridge according to claim 6.