JP2000131941A - Developing device, developing cartridge and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device and a developing cartridge and the like capable of excellently maintaining the sealing function of an end seal member over a long term and preventing the scattering of developer and the increase of the rotational torque of a developer carrier. SOLUTION: The end seal member 105 abuts on the peripheral surfaces of both ends of a developing roller 102 disposed in an opening 104 at one end of a frame body 101 constituting the developing container of the developing cartridge D so as to prevent toner from being leaked to a lateral direction in the longitudinal direction of the roller 102. The member 105 is made to get under a developing blade 103, and is constituted by flocking flexible fluff 114 such as nylon fiber on an elastic member 110 in order to prevent a gap from being formed between the roller 102 and the member 105 at the lower part of the blade 103 under the blade 103 in the member 105 brought into contact with the roller 102.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image on a recording medium, and more particularly to an improvement in a developing device and a developing cartridge.

[0002]

2. Description of the Related Art An image forming apparatus such as a printer using an electrophotographic process uniformly charges an electrophotographic photosensitive member as an image bearing member, for example, a photosensitive drum, and selectively exposes the photosensitive drum to an image. An electrostatic latent image is formed, the latent image is developed by a developing device using toner as a developer, the obtained toner image is transferred to a recording medium, and the transferred toner image is transferred to the recording medium by heat or pressure. Thus, an image is obtained on a recording medium.

[0003] Such an image forming apparatus involves replenishment of toner to a developing device and maintenance of various process means. As a method for facilitating the replenishment work and maintenance of the toner, a photosensitive drum, a charging means, a cleaning means and the like are used. A cartridge (process cartridge) in which a cartridge is detachably mounted on the main body of the image forming apparatus, and a cartridge (developing cartridge) of the developing device are put into practical use.

As shown in FIG. 4, the developing device in the form of a cartridge has a frame 101 having an opening 104 at one end, which constitutes a developing container for storing toner, and carries the toner to a photosensitive drum. Developing roller (developer carrier) 102 which is rotatably disposed in opening 104 for transporting
A developing blade (developer regulating member) 103 for regulating the amount of toner carried on the developing roller 102; and an end for preventing toner leakage in the longitudinal direction of the developing roller 102 at both ends of the opening 104. A part sealing member 105 and a flexible sheet member 106 for preventing toner from blowing out from gaps between the developing roller 102 and the end sealing member 105 below the opening 104 are provided.

The above-mentioned end seal members 105 are in contact with the peripheral surfaces of both ends of the developing roller 102 on the side of the developing frame 102,
Furthermore, the developing blade 103 is installed in contact with both ends of the developing blade 103.
As shown in FIGS. 4 and 5, the end seal member 105 and the developing blade 103 are overlapped with each other, and the end seal member 105 is developed at the overlapped portion. It is sunk under the blade 103.

[0006]

However, since the end seal member 105 has the elastic member 110 provided with the flexible member 112 such as felt, which is relatively rigid, the end seal member 105 is in close contact with the developing roller 102. End seal member 1
05, the developing roller 102 is positioned below the developing blade 103.
And a gap A is generated between them.

For this reason, in the case of using a toner having high fluidity, which is often used in recent years in pursuit of high image quality,
There is a problem that the toner easily enters the gap A along the path indicated by the arrow B shown in FIG.

When the toner enters the gap A, the sealing function of the end seal member 105 is lost, and not only the toner is scattered from the developing device but also the toner further enters the end seal member 105, Developing roller 102
Causes an increase in rotational torque.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sealing function of an end sealing member for a long period of time, and to prevent the developer from scattering and an increase in rotational torque of a developer carrying member. Developing device that enables
An object of the present invention is to provide a developing cartridge and an image forming apparatus.

[0010]

The above object is achieved by a developing device, a developing cartridge and an image forming apparatus according to the present invention. In summary, the present invention relates to a developing device used in an image forming apparatus using an electrophotographic method, wherein a developing container containing a developer having an opening at one end, and an image bearing member carrying the developer are provided. A developer carrier rotatably disposed in the opening, a regulating member for regulating the amount of developer carried on the developer carrier, and a periphery of both ends of the developer carrier. An end seal member that abuts against the surface and prevents the developer from leaking laterally in the longitudinal direction of the developer carrier, wherein the end seal member implants fluff on the elastic member. A developing device.

According to the present invention, preferably, the fluff is electrostatically planted on the elastic member. The length of the fluff is 0.3 to 3
mm. The fluff is made of a chemical fiber. The chemical fiber is nylon or rayon. The surface of the fluff was subjected to a silicone treatment.

Further, the present invention is a developing cartridge in which the above-mentioned developing device is configured to be detachable from an image forming apparatus main body. Further, the present invention is an image forming apparatus provided with the above-mentioned developing device. Still another aspect of the present invention is an image forming apparatus including the developing cartridge.

[0013]

Embodiments of the present invention will be described below in more detail with reference to the drawings.

FIG. 1 is an overall configuration diagram showing an embodiment of the image forming apparatus of the present invention. The present image forming apparatus is configured as a color laser printer that forms a color image by an electrophotographic method.

As shown in FIG. 1, the color laser printer has an electrophotographic photosensitive member (photosensitive drum) 1 rotating at a constant speed as an image carrier, and the surface of the photosensitive drum 1 is And a laser beam corresponding to the image information is emitted from the exposure unit 3 to form an electrostatic latent image on the photosensitive drum 1. This electrostatic latent image is formed by a developing device of a color corresponding to the latent image. It is developed and visualized as a toner image.

In this embodiment, a developing cartridge D in which developing devices for yellow, magenta, cyan, and black are detachably attached to the printer body, that is, a yellow developing cartridge Dy, a magenta developing cartridge Dm, a cyan developing cartridge Dc, and a black developing cartridge Db.

In this manner, the toner images of the respective colors sequentially formed on the photosensitive drum 1 are sequentially superimposedly transferred onto a belt-like intermediate transfer member, that is, the surface of the intermediate transfer belt 4a. A color image is formed thereon. The color image is transferred by the transfer unit 6 onto the surface of a recording medium (for example, a recording paper, an OHP sheet, etc.) P conveyed by the conveying unit 5 from the feeding unit. The recording medium P is sent to the fixing unit 7 to fix the color image, and is discharged to the discharge unit 8 on the upper surface of the printer.

The configuration of each section of the image forming apparatus will be described in detail.

The photosensitive drum 1, the charging means 2, and the cleaning means 9 are integrated into a drum unit U. The drum unit U is detachably supported by the printer main body 30, and the user can easily replace the cartridge U in accordance with the life of the photosensitive drum 1.

The photosensitive drum 1 has an organic photoconductor layer coated on the outer peripheral surface of an aluminum cylinder having a diameter of about 50 mm, and is rotatably supported by a container-like frame 9a of a cleaning means 9 also serving as a holder. ing. Photosensitive drum 1
Is rotated counterclockwise in FIG. 1 by a drive motor (not shown) in accordance with an image forming operation.

The charging means 2 is a conductive roller using a contact charging method. The conductive roller 2 is brought into contact with the photosensitive drum 1 and a voltage is applied to the conductive roller 2 so that the photosensitive roller 1 is charged. Charges the surface uniformly.

When an image signal is given to a laser diode (not shown), the exposure means 3 irradiates the polygon mirror 3a with image light corresponding to the image signal. The polygon mirror 3a is a scanner motor 3b
The image light that is rotated at a high speed and reflected by the polygon mirror 3a selectively exposes the surface of the photosensitive drum 1 that rotates at a constant speed through the imaging lens 3c and the reflecting mirror 3d, so that the surface of the photosensitive drum 1 is statically exposed. An electrostatic latent image is formed.

This latent image is developed for each color by a developing means, and the obtained toner image of each color is transferred to the surface of the intermediate transfer belt 4a.

The transfer residual toner remaining on the surface of the photosensitive drum 1 is removed by the cleaning blade 9 of the cleaning means 9.
a and is stored in the waste toner container 9c formed in the frame 9a. The capacity of the waste toner container 9c is
The waste toner stored therein is set so as not to fill the waste toner container 9c earlier than the life of the photosensitive drum 1. The waste toner in the waste toner container 9c is removed to one place by exchanging the process cartridge U when the photosensitive drum 1 reaches the end of its life.

The intermediate transfer belt 4a has a driving roller 4b, a secondary transfer opposing roller 4c, a driven roller 4d, and a pressing roller 4 near the driven roller 4d.
Together with j, the intermediate transfer device 4 is configured to be detachable integrally with the printer main body 30. In this embodiment, the intermediate transfer belt 4a has a circumference of 440 mm.

The intermediate transfer belt 4a is driven by the driving roller 4b to travel in the direction of arrow R4, and the toner images of the respective colors are sequentially superimposed on the photosensitive drum 1 in a primary transfer manner. It has a role as a second image carrier for collectively secondary transferring the images to the recording medium P.

The press roller 4j presses the intermediate transfer belt 4a against the photosensitive drum 1 during the primary transfer, and retreats to a position where the intermediate transfer belt 4a is separated from the photosensitive drum 1 after the primary transfer is completed.

The secondary transfer of the toner image onto the recording medium P from the intermediate transfer belt 4a is performed by a transfer roller 6 as a transfer unit. The transfer roller 6 has a metal shaft covered with a medium-resistance foamed elastic body, and is provided so as to be able to freely contact and separate from the intermediate transfer belt 4a.

During the primary transfer of the four-color toner image onto the intermediate transfer belt 4a, the transfer roller 6 is positioned below as shown by the solid line in FIG. 1 so as not to disturb the image. It is separated from the intermediate transfer belt 4a. The transfer roller 6 is moved by the cam mechanism in accordance with the transfer timing of the four-color toner image from the intermediate transfer belt 4a.
Then, the transfer roller 6 moves to an upper position as shown by a dashed line, and the transfer roller 6 is pressed against the intermediate transfer belt 4 via the recording material P with a predetermined pressure. At the same time, a bias voltage is applied to the transfer roller 6, and the four color toner images on the intermediate transfer belt 4 are transferred to the recording material P.

As shown in FIG. 1, the transport means 5 includes a paper feed cassette 5a containing a plurality of recording media P, a pickup roller 5b, a feed roller 5c1, a retard roller 5c2 for preventing double feed, and a pair of transport rollers. 5d, transport guide 5g,
It comprises a pair of registration rollers 5e, a conveyance guide 5g, and a discharge roller 5f.

At the time of image formation, the pickup roller 5b
Rotates according to the image forming operation, and separates and feeds the recording media P in the paper feed cassette 5a one by one. The recording material medium P sent out from the paper feed cassette 5a is guided by a conveyance guide 5g, and the recording medium P reaches a registration roller pair 5e via a conveyance roller pair 5d. During the image forming operation, a non-rotating operation in which the registration roller 5e keeps the recording medium P standing by and a rotating operation in which the recording medium P is transported toward the intermediate transfer belt 4 are performed in a predetermined sequence.

Outside the intermediate transfer belt 4a, a cleaning unit 4e is provided at a predetermined position on the downstream side of the secondary transfer section so as to be able to contact and separate from the surface of the intermediate transfer belt 4a. After the completion of the secondary transfer, the cleaning unit 4e brings the charging roller 4f into contact with the surface of the intermediate transfer belt 4a, and charges the secondary transfer residual toner remaining on the surface of the intermediate transfer belt 4a with a charge opposite to that at the time of transfer. give. As a result, the secondary transfer residual toner having the opposite charge is electrostatically attached to the photosensitive drum 1 and collected by the cleaning unit 9.

The method of cleaning the intermediate transfer belt 4a is not limited to the above-mentioned electrostatic cleaning, but may be a mechanical method such as a blade or a fur brush, or a combination of these methods.

The recording medium P on which the color image has been transferred is conveyed to the fixing means 7 and is subjected to fixing of the toner image. The fixing unit 7 includes: a fixing roller 7a that applies heat to the recording medium P;
Pressure roller 7b for pressing recording medium P against fixing roller 7a
It is provided with. The fixing roller 7a and the pressure roller 7b are formed as hollow rollers, and a heater is built in the hollow portion. Fixing roller 7a, pressure roller 7b
Is rotated at a predetermined speed, is conveyed while applying heat and pressure to the recording medium P, and fixes the toner image on the recording medium P.

The recording medium P on which the toner image has been fixed is discharged to the discharge section 8 by the discharge roller pair f of the conveying means 5.

The developing cartridge D according to the present embodiment will be described. As described above, according to the present invention, the developing devices D for each color are detachably attached to the printer main body.
(Dy to Db). These developing cartridges D are mounted on a cylindrical rotary 100, and each of the developing cartridges D is sequentially conveyed to a developing position facing the photosensitive drum 1 by rotation of the rotary 100 to be used for development. .

The basic structure of the developing cartridge D is the same as that of the conventional developing cartridge, and as shown in FIG. 4, a frame 101 constituting a developing container for storing a toner having an opening 104 at one end; A developing roller (developer carrying member) 102 rotatably disposed at the opening 104 for carrying the toner and transporting the toner to the photosensitive drum;
A developing blade (developer regulating member) 103 for regulating the amount of toner carried on the upper end; an end seal member 105 for preventing toner from leaking in the longitudinal direction of the developing roller 102 at both ends of the opening 104; And a flexible sheet member 106 for preventing toner from blowing out from gaps between the developing roller 102 and the end seal member 105 below the opening 104.

The above-mentioned end seal member 105 is similarly
The developing blade 102 of the end seal member 105 is installed in contact with the peripheral surfaces of both ends of the developing roller 102 on the side of the developing frame 102 and further in contact with both ends of the developing blade 103.
In order to facilitate the close mounting on the end of FIG.
As shown in FIG. 5, the end seal member 105 and the developing blade 103 overlap each other, and the end seal member 105 is sunk under the developing blade 103 at the overlapping portion.

However, conventionally, as shown in FIG. 5, the end seal member 105 is provided with a flexible member 112 such as felt which is relatively rigid in the elastic member 110. The developing roller 1 is attached to the end sealing member 105 which is in close contact with the lower portion of the developing blade 103.
02.

Therefore, in this embodiment, as shown in FIG. 2, a flexible fluff 114 is planted on the elastic member 110 to form the end sealing member 105. Elastic member 110
Specifically, a method of fixing the fluff 114 using high-voltage static electricity was used for flocking the fluff 114. The length of the fluff 114 is appropriately set in accordance with a gap formed between the lower part of the developing blade 103 and the developing roller 102.

As a result, the fluff 114 of the end seal member 105 which is in close contact with the developing roller 102 stands upright in the direction of the developing roller 102 below the developing blade 103 as shown in FIG. As a result, no gap is formed between the end seal member 105 and the developing roller 102 below the developing blade 103.

Therefore, even if toner having high fluidity for improving image quality is used for the developing cartridge D, there is still room for the problem that the toner itself enters the gap between the end seal member 105 and the developing roller 102. In addition, the sealing function of the end seal member 105 can be maintained satisfactorily for a long period of time, so that the toner does not scatter and the rotational torque of the developing roller 102 does not increase.

Embodiment 2 In this embodiment, the fixing using high-voltage static electricity
Fuzz 114 having a length of 0.3 to 3 mm was implanted in the elastic member 110 to form an end seal member 105.

When the end seal member 105 is brought into close contact with the developing roller 102, the fluff 114 of the end seal member 105 causes a gap between the end seal member 105 and the developing roller 102 below the developing blade 103. Can be prevented, and the end seal member 105 can be prevented for a long time.
By maintaining the sealing function satisfactorily, scattering of toner and an increase in the rotational torque of the developing roller 102 could be prevented.

Embodiment 3 According to the present invention, as the fluff 114 of the end seal member 105, a synthetic fiber such as a synthetic fiber such as nylon or a regenerated fiber such as rayon can be suitably used.

In this embodiment, the end sealing member 105 is formed by implanting nylon fibers having a length of 03 to 3 mm on the elastic member 110 by fixing using high-voltage static electricity.

According to this embodiment, the end seal member 10 is also provided.
5, the fluff 114 prevents the gap between the developing roller 102 and the developing roller 102 under the developing blade 103, maintains the sealing function of the end seal member 105 well for a long time, and scatters toner and rotates the developing roller 102. An increase in torque was prevented.

Embodiment 4 According to the present invention, the feather 114 of the end sealing member 105 can be subjected to a smoothing treatment such as a silicone treatment on the fiber surface.

In this embodiment, the elastic member 110 is implanted with rayon fibers having a length of 03 to 3 mm by fixing using high-voltage static electricity, and then the nylon fibers are coated with a silicone resin. 105.

According to this embodiment, the end sealing member 10 is also provided.
The fluff 114 of No. 5 can prevent the gap between the developing roller 102 and the developing roller 103 below the developing blade 103, and can maintain the sealing function of the end sealing member 105 well for a long time.
The scattering of the toner and the increase in the rotational torque of the developing roller 102 were prevented.

In each of the above embodiments, the developing device has been described with reference to the developing cartridge provided in the laser beam printer. However, the present invention can be applied to a developing device which does not employ a cartridge system. Further, the image forming apparatus can be applied not only to a printer but also to an image forming apparatus such as a copying machine, a facsimile machine, and a word processor.

[0052]

As described above, according to the present invention,
An end seal member that contacts the peripheral surfaces of both ends of the developer carrier of the developing device to prevent the developer from leaking laterally in the longitudinal direction of the developer carrier is provided by an elastic member made of a fiber such as nylon. Since a fluff having flexibility is planted, a gap is prevented from being formed between the end seal member and the developer carrier even under the developer regulating member, and the end seal member is formed for a long time. A good sealing function can be maintained, and it is possible to prevent scattering of the developer and an increase in the rotational torque of the developer carrier.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of an image forming apparatus of the present invention.

FIG. 2 is a sectional view showing an end seal member of a developing cartridge installed in the image forming apparatus of FIG. 1;

FIG. 3 is a cross-sectional view illustrating a state where the end seal member of FIG. 2 is disposed at an end of a developing roller of a developing cartridge.

FIG. 4 is a front view of the conventional developing cartridge viewed from the opening side.

5 is a cross-sectional view illustrating a state where an end seal member of the developing cartridge of FIG. 4 is disposed at an end of a developing roller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum 101 Developing frame 102 Developing roller 103 Developing blade 104 Opening 105 End seal member 110 Elastic member 114 Fluff D Developing cartridge

Claims (9)

[Claims] 1. A developing device for use in an image forming apparatus using an electrophotographic method, wherein a developing container containing a developer having an opening at one end, a developer carried thereon, and transported to an image carrier. A developer carrier rotatably disposed in the opening; a regulating member for regulating the amount of developer carried on the developer carrier; and a peripheral member at both ends of the developer carrier. An end seal member for preventing the developer from leaking laterally in the longitudinal direction of the developer carrying member, wherein the end seal member is formed by fuzzing an elastic member with fluff. Characteristic developing device. 2. The developing device according to claim 1, wherein said fluff is electrostatically implanted on said elastic member. 3. The developing device according to claim 1, wherein said fluff has a length of 0.3 to 3 mm. 4. The method according to claim 1, wherein said fluff is made of chemical fiber.
Item 3. The developing device according to any one of Items 3. 5. The developing device according to claim 4, wherein said chemical fiber is nylon or rayon. 6. The developing device according to claim 4, wherein a surface of said fluff is subjected to a silicone treatment. 7. A developing cartridge in which the developing device according to claim 1 is detachably attached to an image forming apparatus main body. 8. An image forming apparatus comprising the developing device according to claim 1. 9. An image forming apparatus comprising the developing cartridge according to claim 7.