JPH03269563A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an inexpensive miniature device by insulating parts of nonphotosensitive material not coated with a photosensitive material to dispense with insulation of parts of a developing machine possible to come into contact with the nonphotosensitive layer. CONSTITUTION:After a raw aluminum drum 1 is washed, and both ends of the drum 1 is deposited on the surface of the drum 1 except both parts 3 to form a photosensitive layer 2. This layer 2 is uniformly electrically charged and imagewise exposed to light to form an electrostatic latent image, and developed with a reversely charged toner containing a fine carbon powder, thus permitting all the surface of the photosensitive body to be insulated in the dark and bias voltage not to drop even when the surface comes into contacts with a developing machine through a iron powder, accordingly the parts of the developing machine possible contact with the nonphotosensitive parts to be made unnecessary to be insulated, and the inexpensive small device to be obtained.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a photoreceptor used in electrophotographic devices such as copying machines and optical printers.

[Conventional technology]

As is well known, a method (Carlson method) of forming an image with a colored resin on recording paper by utilizing the photoconductivity of a photoreceptor is widely used in electrophotographic devices such as copying machines and optical printers. A photoreceptor that forms an image using light is an important device in an electrophotographic apparatus. FIG. 4 is a partial sectional view showing a conventional electrophotographic photoreceptor disclosed in, for example, Kokai Technical Report No. 86-4746. In the figure, 1 is a drum tube having flanges 1a at both ends; A photoreceptor material layer made of selenium alloy or the like is applied to the central outer surface of the tube 1 by vapor deposition, and a flange 1a provided on the drum tube 1 prevents the photoreceptor material layer 2 from being scratched. Next, the operation will be explained. The electrophotographic photoreceptor is made by cleaning a drum tube 1, which is, for example, an aluminum tube, and then depositing a selenium alloy on its surface to form a photoreceptor material layer 2. A developing section that converts the electrostatic latent image formed on the electrophotographic photoreceptor into an image using toner, which is colored plastic particles, and a portion of the drum tube 1 on which the photoreceptor material layer 2 is not applied are connected. If they come into contact for some reason, the DC bias applied to the developing section will be short-circuited through the drum tube 1, resulting in so-called bias drop, and the density of the recorded image will be extremely reduced. One of the causes of this bias drop is that iron powder from the developer accumulates at the end of the developing device and comes into contact with the end of the drum tube 1, causing a short circuit in the developing bias.

[Problem to be solved by the invention]

Since the conventional electrophotographic photoreceptor is constructed as described above, the photoreceptor material layer 2 of the developing machine and the drum pipework that serves as the base material is
If the non-photoreceptor material layer that is not coated comes into contact with the non-photoreceptor material part for some reason, the developing bias will be short-circuited, and the length of the photoreceptor material layer may be made longer than necessary, and there is a possibility that the photoreceptor material layer may come into contact with the non-photoreceptor material part. Since certain parts of the developing machine must be insulated, there are problems in that the electrophotographic apparatus becomes larger and more expensive. This invention was made in order to solve the above-mentioned problems, and it shortens the length of the photoreceptor material layer, which is a factor that increases the depth of an electrophotographic device, and also shortens the length of the photoreceptor material layer, which makes it possible to contact the non-photoreceptor material layer. To provide an electrophotographic photoreceptor which makes it possible to obtain an inexpensive and small-sized electrophotographic device by eliminating the need for insulation at the parts of a developing machine that are sensitive to heat.

[Means to solve the problem]

The electrophotographic photoreceptor according to the present invention has a photoreceptor material layer applied to the center of the surface of the base material, and a non-photoreceptor material portion on which no photoreceptor material is applied at the edge of the surface of the base material. This is an i-precept in which the body material part is an insulating part.

[Effect]

In the electrophotographic photoreceptor according to the present invention, insulation is applied to the surface end portion that is likely to come into contact with the developing machine, so that there is no need to insulate the developing machine part that is likely to come into contact with the electrophotographic photoreceptor. The manufacturing cost of the electrophotographic device can be reduced.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a partial cross-sectional view showing one embodiment of the present invention, and the configuration in FIG. 1 is different from the conventional example shown in FIG. That's true. In the electrophotographic photoreceptor shown in FIG. 1, after cleaning the drum tube 1, both ends of the drum tube 1 are treated with oxidized alumite to form an insulating part 3, and then the drum tube 1 is placed in the center of its surface. The photoreceptor material layer 2 is formed by vacuum-depositing a selenium alloy. Next, the operation will be explained. For example, when an electrophotographic photoreceptor is used as a copying machine, the electrophotographic photoreceptor is charged to the same charge as the original image pattern to be copied, and then a finely powdered carbon toner charged with the opposite polarity is used to create a static image. Develop the electrolatent image. In this way, since the photoreceptor material layer 2 is formed at both ends of the drum tube 1 with the insulating portion 3 in the center, the entire surface of the electrophotographic photoreceptor becomes an insulating surface in the dark area, and the developing machine and the electrophotographic photoreceptor surface Bias drop does not occur even if there is contact with iron powder from the developer. Therefore, there is no need to insulate parts of the developing machine that are likely to come into contact with the electrophotographic photoreceptor, and the manufacturing cost of the electrophotographic apparatus can be reduced. Furthermore, by forming an electrophotographic photoreceptor in which an insulating section 3 is provided at the end of the drum tube 1, the distance between the electrophotographic photoreceptor 4 and the developing rotating sleeve 5 can be kept constant as shown in FIG. The electrophotographic photoreceptor 4 is attached to the developing section to maintain the
By using the metal roller 6 in this way, it is possible to improve the spacing accuracy between the electrophotographic photoreceptor 4 and the developing rotary sleeve 5. Quality can be stabilized. In the above embodiment, after the end of the drum tube 1 is treated with oxidized alumite, a selenium alloy is vacuum-deposited to form the photoreceptor material layer 2.
The electrophotographic photoreceptor shown in FIG. 3 has a structure in which a photoreceptor material layer 2 is formed by vacuum-depositing a selenium alloy on the entire surface of a drum tube 1, and then a flange that has been previously insulated is 7 fitted to both ends of the drum tube 1,
Manufacturing of electrophotographic photoreceptors becomes easier. In the above embodiments, a selenium alloy is used as the photoreceptor material, but any material such as amorphous silicone, an organic optical semiconductor, or a dispersed system of an inorganic optical semiconductor such as zinc oxide or cadmium sulfide may be used. Further, in the above embodiment, the insulating part is formed by an oxidized alumite treatment, but the insulator is not limited to this, and any inorganic or organic insulator may be used as long as it is stable against ozone oxidation. . Further, in the above embodiment, an aluminum drum tube was used as the base material, but any shape including the material may be used, such as a belt shape or a sheet shape.

【Effect of the invention】

As described above, according to the present invention, insulation is applied to the surface of the electrophotographic photoreceptor on which the photoreceptor material is not applied, so even if the developing machine and the electrophotographic photoreceptor come into contact for some reason, the developing bias will not be short-circuited. Therefore, there is no need to insulate the parts of the developing machine that may come into contact with the electrophotographic photoreceptor, resulting in an inexpensive and compact product.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view showing an electrophotographic photoreceptor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing an electrostatic copying machine in which the electrophotographic photoreceptor of FIG. 1 is used, and FIG. is a partial cross-sectional view showing an electrophotographic photoreceptor according to another embodiment of the present invention,
FIG. 4 is a partial sectional view showing an example of a conventional electrophotographic photoreceptor. 1 is a base material (drum tube), 2 is a photoreceptor material layer, and 3 is an insulating part. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. (2 others) 1st m5 (B) 3rd WJ

Claims (1)

[Claims] In an electrophotographic photoreceptor having a base material in which a photoreceptor material layer is applied to the center of the surface and a non-photoreceptor material portion on which no photoreceptor material is applied at the edge of the surface, the non-photoreceptor material portion is formed as an insulating portion. An electrophotographic photoreceptor characterized by: