JP2616485B2 - Process cartridge and image forming apparatus to which the process cartridge can be attached and detached - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process cartridge and an image forming apparatus to which the process cartridge can be attached and detached.

Here, the image forming apparatus is an electrophotographic copying machine, a laser beam printer or the like.

[0003]

2. Description of the Related Art In recent years, in an image forming apparatus such as an electrophotographic copying machine or a laser beam printer, a conventional corona discharger has been used as a means for applying a charge to a photoconductor as an image carrier in order to form an electrostatic latent image. A roller charging system in which a roller (hereinafter, referred to as a charging roller) to which a bias is applied instead of an electric appliance is brought into contact with a photosensitive member has been proposed.

[0004] This method is different from the method using corona discharge,
. The device can be downsized. It does not require a high voltage power supply as large as a corona discharger. This has the advantage that there is no contamination on the photoreceptor by the corona product.

[0005]

However, such a roller charging system also requires means for removing dirt on the surface of the charging roller. That is, there is no chance that foreign matter such as scattering of the developer from the developing unit or dust and dirt from the outside adheres to the charging roller, and when they adhere to the charging roller, only the portion on the photoconductor is charged. May not be applied, thus resulting in a non-uniform image.

[0006] On the other hand, in this type of image forming apparatus, in order to improve reliability, operability and ease of maintenance, the photoreceptor and the image forming means around the photoreceptor are integrally formed and integrated from the apparatus main body. There is known a process cartridge system which can be freely attached and detached.

The use of the above-described roller charging method as the charging means in such a process cartridge has the above-mentioned advantages, and greatly improves the performance.

However, the charging roller in the process cartridge also has the above-mentioned problem of the adhesion of foreign matter, and therefore some kind of cleaning means (cleaning means) for the surface of the charging roller is required. Incorporation together with the process cartridge complicates the configuration of the process cartridge, increases the size of the process cartridge, and impairs the advantages of roller charging. Further, when it is desired to make the process cartridge ultra-small, it is difficult to secure a space for disposing the cleaning means.

Accordingly, the present invention provides a process cartridge and an image forming apparatus to which the process cartridge can be attached and detached, in which a roller charging means is used as a photosensitive member charging means incorporated in the process cartridge without increasing the size of the process cartridge. Moreover, it is an object of the present invention to make it possible to easily clean the charging roller provided in the cartridge.

[0010]

SUMMARY OF THE INVENTION The present invention is a process cartridge having the following configuration and an image forming apparatus to which the process cartridge can be attached and detached.

(1) A process cartridge detachable from the main body of an image forming apparatus, comprising: a photoreceptor; a roller charging means for charging the photoreceptor; Is provided along the longitudinal direction of the roller in the portion of the process cartridge frame corresponding to the roller charging means, in which the roller charging means cleaning means disposed on the image forming apparatus main body enters when the apparatus is mounted on the image forming apparatus. A process cartridge characterized by having been made.

(2) The process cartridge according to (1), wherein the process cartridge has an opening / closing shutter member for holding the opening closed when the process cartridge is detached from the image forming apparatus.

(3) The process cartridge according to (1), wherein the process cartridge has a developing device for developing a latent image formed on a photosensitive member.

(4) The process cartridge according to (1), wherein the process cartridge has a cleaning device for cleaning a photosensitive member.

(5) The process cartridge according to (1), wherein the image forming apparatus is an electrophotographic copying machine.

(6) The process cartridge according to (1), wherein the image forming apparatus is a laser beam printer.

(7) In an image forming apparatus capable of mounting a process cartridge and forming an image on a recording medium, a photoreceptor, a roller charging means for charging the photoreceptor, and a frame body incorporating these components Mounting means for mounting a process cartridge having an opening along the length of the roller at a portion corresponding to the roller charging means of the process cartridge frame, and provided on the image forming apparatus main body side. Cleaning means for cleaning the roller charging means, which enters the process cartridge from the opening of the process cartridge frame and comes into contact with the roller charging means when the process cartridge is mounted on the image forming apparatus main body; An image forming apparatus comprising: a conveying unit that conveys a recording medium.

(8) The image forming apparatus according to (7), wherein the process cartridge has a developing device for developing a latent image formed on a photosensitive member.

(9) The image forming apparatus according to (7), wherein the process cartridge has a cleaning device for cleaning a photosensitive member.

(10) The image forming apparatus according to (7), wherein the image forming apparatus is an electrophotographic copying machine.

(11) The image forming apparatus according to (7), wherein the image forming apparatus is a laser beam printer.

[0022]

[Action] That is, the means for cleaning the roller charging means in the process cartridge is not provided on the process cartridge side, but is provided on the image forming apparatus main body side, and a portion corresponding to the roller charging means is provided on the process cartridge frame along the roller length. When the process cartridge is mounted on the image forming apparatus main body with the opening provided, the cleaning means provided on the image forming apparatus main body side enters the process cartridge from the opening of the process cartridge frame. With the configuration in which the roller charging unit is brought into contact with the roller charging unit, the cleaning of the roller charging unit is performed by the above-described contact cleaning unit with the rotation of the roller charging unit due to the operation of the image forming apparatus, so that a good and stable image is always obtained. Becomes possible.

[0023] Since the process cartridge itself is not provided with a cleaning means for the roller charging means, it is possible to prevent the process cartridge from becoming complicated and large, and to avoid an increase in cost, thereby increasing the degree of freedom in designing a very small process cartridge.

That is, no roller cleaning means, which causes the process cartridge to become complicated and large, and to increase the cost, is not incorporated, and the occurrence of an image defect due to the surface contamination of the roller can be easily and easily dealt with.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment described below, at least a photosensitive member and a roller-shaped contact charging means (roller charging means, charging roller) for charging the photosensitive member surface are incorporated in a process cartridge frame to form an image. The process cartridge is detachable from the apparatus main body, and has an opening along the roller length at a portion corresponding to the charging roller of the process cartridge frame to clean the surface of the charging roller in the process cartridge. When the process cartridge is mounted on the image forming apparatus main body side, the roller charging means which enters the process cartridge from the opening of the process cartridge frame and comes into contact with the roller charging means is cleaned. Cleaning means.

FIG. 1 is a longitudinal sectional view of an electrophotographic copying apparatus as an image forming apparatus according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the image forming apparatus with a process cartridge removed.

In FIG. 1, reference numeral 1 denotes a process cartridge, in which a photosensitive drum 2 as an image carrier, a charging roller 3 as a roller charging means, a developing device 4 and a cleaning device 5 are incorporated. 4a is a hopper for storing the developer T, and 4b is a hopper for storing the developer T on the photosensitive drum 2.
The rotating body for supplying the Reference numeral 21 denotes an opening provided in a portion corresponding to the charging roller 3 of the process cartridge frame along the length of the roller. Reference numerals 34 and 35 denote an opening / closing shutter for the opening 21 and an opening / closing shutter for the image exposure opening 36 provided on the process cartridge side. When the process cartridge 1 is detached from the image forming apparatus main body A as shown in FIG. 2, these shutters 34 and 35 close the opening 21 and the image exposure opening 36, respectively, to close the light of the photosensitive drum 2. Prevent fatigue.

In this embodiment, the process cartridge 1 is detachably mounted to the image forming apparatus main body A in the lateral direction (in the directions indicated by arrows c and d in FIG. 2) from the cartridge mounting / dismounting opening 25 as shown in FIG. Things. Reference numeral 26 denotes an opening / closing door for closing the opening 25 for attachment / detachment. When the cartridge 1 is loaded into the main assembly A of the apparatus, the shutters 34 and 35 are automatically opened by hooks and the like (not shown) (see FIG. 2).
(Fig. 1).

In FIG. 1, reference numeral 8 denotes a document table which is made of a transparent member and reciprocates in the direction indicated by an arrow a in the figure. Reference numeral 10 denotes a lamp for illuminating the original O, and reference numeral 11 denotes a short-focus optical element array for forming and exposing the reflected light from the original O illuminated by the lamp to the surface of the photosensitive drum 2.

The photosensitive drum 2 is rotated at a predetermined peripheral speed in a direction indicated by an arrow b in the drawing, is uniformly charged to a predetermined polarity by the charging roller 3, and is sequentially subjected to image exposure by the optical element array 11. Thus, a latent image corresponding to the original image is formed on the drum surface. The latent image is developed by the developing device 4 to form a developed image to be transferred onto a transfer material on the drum surface, and the latent image moves toward the transfer corona discharger 12 as a transfer portion by the subsequent rotation of the drum 2.

On the other hand, the transfer material P is transported from the paper feed tray 13 to the transfer section by the transport roller 14 and the timing roller 15, and the developed image is transferred by the transfer corona discharger 12. The transfer material P having completed the transfer is transferred to the separator 1
After being separated from the drum surface by 6, it is sent to a fixing device 18 via a conveyance path 17 and is fixed, and is sent out onto a discharge tray 20 by a discharge roller 19. The developer remaining on the photosensitive drum surface is removed by the cleaning device 5, and the above-described image forming process is repeatedly performed.

In the present embodiment, the charging roller 3 has a configuration in which a conductive rubber 3b such as EPDM is coated around a metal shaft 3a, and rotates while contacting the photosensitive drum 2. A power supply is connected to the charging roller 3 through a contact (not shown) or the like, and a DC voltage or a DC voltage on which an AC voltage is superimposed is applied, and a charge is applied to the photosensitive drum 2 by contact with the photosensitive drum 2. It is.

Reference numeral 30 denotes a cleaning means (cleaning means) for cleaning the surface of the charging roller 3, which is provided on the image forming apparatus main body A side. As described above, when the cartridge 1 is loaded into the apparatus main body A, the shutters 34 and 35 are automatically opened by hooks and the like (not shown), and when the cartridge 1 is properly mounted in the apparatus main body A, As shown in FIG.
From the cleaning means 30 on the side of the image forming apparatus main body A
Enters the cartridge 1 and the process cartridge 1
It is configured to be in a state of being pressed against the surface of the charging roller 3 along the longitudinal direction.

In the cleaning means 30, a felt holding member 32 is attached via a spring 31 in the vicinity of the process cartridge mounting portion in the apparatus main assembly A in the case of the drawing, and a pad-like felt 33 is attached to the holding member 32. Here is an example. The felt 33 of the cleaning means 21 is pressed against the charging roller 3 by a spring 31 at a predetermined pressure. As a result, foreign matter attached to the peripheral surface of the charging roller 3 is automatically cleaned and removed by the rotation of the charging roller 3 accompanying the operation of the image forming apparatus.

The cleaning means 30 may be configured such that a film-like material such as a polyester film or a polyethylene film is brought into contact with the charging roller 3 in order to scrape foreign matters, or may be a brush-like material.

The cleaning means 30 is simply a charging roller 3
It is sufficient to remove only the above coarse dust and the like, and since the roller 3 is usually not so dirty, there is no concern that excessively accumulated foreign matter will be accumulated in the cleaning means, or that the cleaning means will be excessively worn or fatigued. . Therefore, it is possible to sufficiently maintain the performance of the process cartridge until the life of the process cartridge (several thousand to 10,000) comes.

Since the process cartridge 1 itself is not provided with the cleaning means 30 for the charging roller 3,
The process cartridge 1 can be prevented from becoming complicated and large, and the cost can be prevented from increasing, and the degree of freedom in designing a very small process cartridge can be increased.

Although the above embodiment has been described by taking an electrophotographic copying apparatus as an example, the present invention can be applied to various image forming apparatuses such as a laser beam printer.

In the illustrated example, the process cartridge 1 includes the photosensitive drum 2, the charging roller 3, the developing device 4, and the cleaning device 5, but any one or both of the developing device 4 and the cleaning device 5 may be used. Not including,
Alternatively, the present invention can also be applied to an apparatus provided with auxiliary exposure means and auxiliary charging means.

[0040]

As described above, according to the present invention, a process cartridge including a roller charging means and an image forming apparatus to which the process cartridge can be attached / detached without increasing the size of the process cartridge. Can be cleaned. In other words, the roller cleaning means, which causes the process cartridge to become complicated and large, and raises the cost, is not incorporated in the process cartridge, and the roller charging means can be sufficiently cleaned without any problem of surface contamination of the roller charging means. , Fully utilizing the features of the roller charging means,
There are effects that a good and stable image can always be obtained, and that the process cartridge can be reduced in size and cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the image forming apparatus with a process cartridge removed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Process cartridge 2 Photoconductor (photosensitive drum) 3 Roller charging means (charging roller) 21 Opening 30 Charging roller cleaning means (cleaning means)

Claims (11)

(57) [Claims] 1. A process cartridge detachable from a main body of an image forming apparatus, comprising: a photoreceptor; roller charging means for charging the photoreceptor; and a frame body having these incorporated therein. An opening, into which the roller charging means cleaning means disposed on the image forming apparatus main body side enters when mounted on the image forming apparatus, is provided along a longitudinal direction of the roller at a portion corresponding to the roller charging means of the process cartridge frame. A process cartridge. 2. The process cartridge according to claim 1, wherein said process cartridge has an opening / closing shutter member for holding said opening closed when said process cartridge is removed from said image forming apparatus. 3. The process cartridge according to claim 1, wherein said process cartridge has a developing device for developing a latent image formed on a photosensitive member. 4. The process cartridge according to claim 1, wherein the process cartridge has a cleaning device for cleaning a photosensitive member. 5. The process cartridge according to claim 1, wherein said image forming apparatus is an electrophotographic copying machine. 6. The process cartridge according to claim 1, wherein said image forming apparatus is a laser beam printer. 7. An image forming apparatus capable of mounting a process cartridge and forming an image on a recording medium, comprising: a photosensitive member; a roller charging means for charging the photosensitive member;
An image forming apparatus, comprising: a frame body incorporating these components; a process cartridge frame having an opening along the length of the roller at a portion corresponding to the roller charging means of the process cartridge frame; A roller charging unit that is provided on the main body side and that enters the process cartridge from the opening of the process cartridge frame and contacts the roller charging unit when the process cartridge is mounted on the image forming apparatus main body; An image forming apparatus comprising: a cleaning unit for cleaning; and a conveying unit for conveying the recording medium. 8. The image forming apparatus according to claim 7, wherein said process cartridge has a developing device for developing a latent image formed on a photosensitive member. 9. The image forming apparatus according to claim 7, wherein said process cartridge includes a cleaning device for cleaning a photosensitive member. 10. The image forming apparatus according to claim 7, wherein said image forming apparatus is an electrophotographic copying machine. 11. The image forming apparatus according to claim 7, wherein said image forming apparatus is a laser beam printer.