JPS6247684A - Image carrier drum - Google Patents

Abstract

PURPOSE:To obtain secure earth operation and to stop the leakage of toner by providing an image carrier drum, where waste toner is guided and stored, internally with a dish type earth member which contacts the entire periphery of the internal wall surface of the drum. CONSTITUTION:A cleaning device 2 is arranged closely to the cylindrical photosensitive drum 1 and toner which remains on the surface of the photosensitive drum 1 without being used for transfer is scraped off by the cleaning device 2, conveyed by a screw conveyor 4, and stored in the space in the photosensitive drum 1. In this case, a dish or cut type earth member 6 is provided on the internal wall surface of a flange 1a on the opposite side from the conveyor 4 and the peripheral part of the earth member 6 is allowed to contact the entire periphery of the internal wall surface of the photosensitive drum 1. Consequently, even if the photosensitive drum 1 swings, the contact between the photosensitive drum 1 and earth member 6 is uninterrupted and no toner leaks out.

Description

Detailed Description of the Invention (1) Purpose of the Invention (Field of Industrial Application) The present invention relates to an image forming apparatus that utilizes an electrostatic transfer process, such as an electrophotographic copying machine or a printer, and particularly relates to an image bearing drum thereof. be.

(Prior art and problems to be solved) Conductive materials formed in a cylindrical shape, an endless belt shape, etc. (a photoconductive layer is formed on the surface of the material, the layer is charged, an electrostatic latent image is formed, developed, and paper Image forming apparatuses that perform image forming operations such as transferring onto a sheet-like transfer material and separating the transfer material are conventionally well known.

In such image forming apparatuses, organic semiconductors have recently come into widespread use as photoconductive layers because they have various advantages such as non-pollution, high productivity, and low cost.

On the other hand, this type of photoconductive layer is sensitive to ultraviolet rays and easily damaged, so it has a limited lifespan and needs to be replaced periodically.

Furthermore, recently, in this type of image forming apparatus, an image bearing member (hereinafter referred to as a photoreceptor), -11? 2. Description of the Related Art Small-sized image forming apparatuses in which a plurality of image forming members such as electrical appliances, a developing device containing toner, and a cleaning device are housed integrally in a cartridge are increasingly being used.

In such a cartridge type, the entire cart is discarded when the toner is consumed.

Since these devices are usually disposable, it is preferable to use a photoreceptor with a long lifespan, as described above, as long as it is cost-permissible.

From this point of view, it has been proposed to use a cylindrical photoreceptor that uses an organic semiconductor for the photoconductive layer, and to have both sides of the photoreceptor, which do not directly contribute to image formation, made of a cost-effective resin material. ing.

By the way, as is well known, in the image forming process of this type of image forming apparatus, the photoconductive layer is uniformly charged and then a light image is irradiated onto it to remove unnecessary charges from the conductive base. Since the electrostatic latent image is formed by dissipating into the substrate, the substrate must be sufficiently grounded in order to form a good quality latent image.

In this case, in the case of a well-known photoreceptor in which at least one of both side surfaces from the portion overlapping the photoconductive layer is made of a conductor such as metal, grounding can be easily established using the rotating shaft. However, this method is not possible with a device whose side surfaces are made of insulating material such as resin or paper as described above, and for this reason, for example, as shown in FIG. No. 10 is known, in which no photoconductive layer is present and a grounding material 11 attached to an appropriate position of the main body is brought into contact with the exposed portion of the conductive base material 10a.

However, with this configuration, the base material itself is usually made of a relatively flexible material such as aluminum, and it is rotating and some movement is unavoidable, so it is necessary to ensure that it is properly grounded. In order to do this, it is necessary to firmly press the grounding material against the base material. Furthermore, toner and other particles are scattered inside the neck brace, and this tends to get between the ground material and the base material and prevent direct contact between the two, so from this point of view as well, it is necessary to press the ground material strongly. be.

As a result, the base material may be worn, and abrasion powder may adhere to the photoreceptor, leading to deterioration of image quality.

In order to cope with such a situation, the present invention provides a good grounding function by arranging a grounding material inside the photoconductor, and furthermore, in the above-mentioned compact image forming apparatus using a cartridge type, To save space,
It is an object of the present invention to provide an image bearing drum which is effective as a means for preventing leakage of toner containing a grounding material when configured to store toner collected by a cleaning means inside the image bearing drum. .

(2) Structure of the Invention (Technical Means for Solving the Problems and Their Effects) In order to achieve the above-mentioned object, the present invention includes a substantially plated plate that is provided inside the image bearing drum and is in contact with the wall surface of the photoreceptor over its entire circumference. It is characterized in that it is constructed by disposing a grounding material in the form of a shape.

With this configuration, the image J11 of the grounding material
Not only can the contact with the holding drum base material be ensured to provide a good grounding effect, but also the earthing material can effectively prevent the toner stored in the drum from leaking to the outside.

(Description of an Embodiment) FIG. 1 is a cross-sectional view of a main part of an embodiment showing a case where the present invention is applied to a photosensitive drum of a cartridge-type copying machine. The arranged cleaning device 2 is attached to the cartridge C,
This cartridge is located on the frame F of the main body of the I machine with a pin! , is held in place by the

The photosensitive drum l consists of a cylindrical base IC made of a conductive material with a photoconductive layer on its surface, and resin flanges la and lb attached to both sides of the base IC. A gear that meshes with a gear 5 connected to a drive source (not shown) is formed in 1a, and is thereby rotated.

Cleaning device: Inside the 1Vt2, a screw conveyor 4 is disposed, like a well-known one, for conveying and discharging the toner scraped from the photosensitive drum by the cleaning device to the outside. A gear (not shown) that meshes with the gear of the flange 1a is attached to the flange 1a, and is driven to rotate as the photoreceptor rotates. The other end of the screw conveyor 4 extends outward from the cleaning device, and this extension is housed within the pipe 3.
It is located at one shaft portion of the photoreceptor 1 and opens into its internal space. Therefore, the toner that does not contribute to transfer and remains on the surface of the photosensitive drum at a transfer site (not shown) and is removed by the cleaning device is then discharged by the screw conveyor 4, and further conveyed by this and stored in the space inside the photosensitive drum. Ru. For this reason, there is no need to provide a separate container for storing waste toner, which is advantageous.

In such a device, in the present invention, a substantially dish-shaped or pot-shaped grounding member 6 is provided on the inner wall surface of the flange 1a on the side opposite to the side where the screw conveyor is located inside the photoreceptor.

The peripheral portion of the ground member 6 is pressed against the inner wall surface of the conductive base material of the photoreceptor, and a bottle 6a is attached to the outer surface.
This engages with a bearing 7 that pivotally supports the photoreceptor, and the pin 6a is biased toward the bearing by a spring 8.

With this structure, the grounding member 6 can be easily grounded, and since the grounding member is inside, even if the photoconductor shakes during operation, it will not interfere with the photoconductor. Contact with the grounding member is not interrupted, and a reliable grounding effect can be ensured. Furthermore, since the grounding member 6 is in close contact with the inner surface of the cylindrical portion of the photoreceptor, it is possible to reliably prevent the waste toner stored in the internal space from leaking to the outside.

In addition to the photosensitive drum, an insulating drum having an insulating layer on its surface is also effective as the image bearing drum.

(3) Effects of the Invention Since the present invention has the above-described configuration, a reliable grounding effect can be obtained, especially in an image forming apparatus in which waste toner is guided and stored in a photoconductor, and the toner can be It is possible to prevent leakage, which greatly contributes to downsizing and cost reduction of the image forming apparatus.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an embodiment in which the present invention is applied to a cartridge-type copying machine, and FIG. 2 is a side view of a part of an example of a known grounding means. l...Sensitive photoreceptor, 2...Cleaning device, 3...
Pipe, 4/11e screw conveyor, 6... Earth member, 7... Bearing,

Claims (1)

[Claims] In an image carrying drum having both sides made of an insulating material and having toner collected by a cleaning means stored therein, a grounding member is provided on at least one inner wall surface of the insulating material, the grounding member being in contact with the entire circumference of the inner wall surface of the image carrying drum. An attached image-bearing drum.