JPS62150258A - Apparatus for producing electrophotographic selenium photosensitive body - Google Patents

Abstract

PURPOSE:To reduce the generation of a problem about quality of a crystalline of the photosensitive layer by inserting a spacer between a supporting body and a substrate, thereby rapidly controlling the temperature of the substrate with a narrow controlling range while depositing the photosensitive layer on the substrate. CONSTITUTION:The depositing material 2 for example the pure selenium is filled in an evaporating source 1 which is provided with the vacuum vessel. The photosensitive layer is vacuum- deposited on the surface of the cylindrical aluminium substrate 5 interposing the spacer 6 between the supporting axis 4 and the substrate 5 by heating the depositing material with a heater 3. The spacer 6 is a hollow body which is sealed tightly. The heating medium 7 is sealed in the hollow body. The heat transmission to the supporting axis 4 from the substrate 5 while depositing is effected between the substrate 5 and the spacer 6, and between the supporting axis 4 and the spacer 6 by conduction respectively, and is effected in the hollow of the spacer by convection. As the contact surfaces among the supporting axis 4, the spacer 6 and the substrate 5 are pressed from the spacer side by a pressure of about 1atm, thereby sticking them with each other, the heat conduction among them is very good, whereby the heat transfer is rapidly effected between the supporting axis 4 and the substrate 5, and enable to the good temperature control which has a good heat responsibility.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to an apparatus for manufacturing a selenium photoreceptor for electrophotography.

[Prior art and its problems]

Selenium photoreceptors for electrophotography are generally formed by vacuum deposition of a photoconductive material such as amorphous selenium, selenium-tellurium alloy, selenium-arsenic alloy, etc. on a cylindrical conductive substrate made of aluminum alloy. This forms a photosensitive layer. In an amorphous state, a selenium-based substance has a very high resistance in the dark, so it has high charging ability and excellent photoconductivity, but when crystallized, the resistance becomes low and there is almost no photoconductivity. Therefore, it is essential that the selenium-based material forming the photosensitive layer of an electrophotographic photoreceptor be in an amorphous state, and if it crystallizes, it will lose its function as a photosensitive layer.

The state of the selenium-based substance forming the photosensitive layer is practically determined by the temperature of the substrate during vacuum deposition to form the photosensitive layer. That is, in the case of pure selenium or a selenium-tellurium alloy, such crystallization becomes a problem when the substrate temperature during vapor deposition is about 80° C. or higher. On the other hand, when the substrate temperature of these substances falls below about 60° C., the photosensitivity of these materials deteriorates as a photoreceptor, which poses a practical problem. Therefore, when pure selenium or a selenium-tellurium alloy is used for a photoreceptor, when vacuum-depositing these materials as a photosensitive layer, the substrate temperature must be kept at 60°C to 80°C, which is considerably lower than the deposition source temperature. , and must be controlled within a narrow temperature range, which poses a major problem when mass producing photoreceptors. Therefore, controlling the substrate temperature during vapor deposition is very important in the production of photoreceptors.

In conventional electrophotographic selenium photoreceptor manufacturing equipment,
Temperature control of the substrate was performed via a support shaft to which the substrate was attached. During vacuum evaporation, a large amount of heat is transferred from the evaporation source to the evaporation material through the evaporation material, but since the heat accumulated through this transfer is in a vacuum, it is transferred from the substrate to the support shaft without relying on convection. released to the outside by However, although the inner surface of the cylindrical base body and the outer surface of the support shaft are mounted so that they are in full contact with each other, it is difficult to achieve complete surface contact, and only partial surface or point contact occurs. As a result, the heat input to the substrate cannot be sufficiently released, and the heat is accumulated in the substrate, raising the substrate temperature and causing crystallization of the selenium-based material in the formed photosensitive layer. Ta. Furthermore, even when the maximum amount of heat is input to the substrate during intense evaporation, lowering the support shaft temperature to such an extent that the substrate temperature does not reach a temperature that may cause crystallization may result in the substrate temperature becoming too low. This is a problem because it occurs.

[Purpose of the invention]

The present invention has been made in view of the problems described above, and an object of the present invention is to provide an apparatus for manufacturing a selenium photoreceptor for electrophotography that can quickly control the temperature of a substrate during vacuum deposition in a narrow control range. purpose.

[Key points of the invention]

An object of the present invention is to attach a cylindrical conductive substrate to a temperature-controllable support shaft provided in a vacuum chamber, and apply selenium or a selenium alloy to the substrate, which is controlled at a predetermined temperature via the support shaft, under vacuum. In the production equipment for electrophotographic selenium photoreceptors that use vapor deposition to form a photosensitive layer, the selenium is hermetically sealed in the atmosphere between the base and the support shaft, and expands due to the pressure difference when the surrounding area is evacuated. This is achieved by using a manufacturing device in which a hollow spacer having a deformable structure is interposed so as to fill the gap between the two.

[Embodiments of the invention]

FIG. 1 is a conceptual cross-sectional view of the inside of a vacuum chamber of an apparatus according to an embodiment of the present invention, in which an evaporation source L disposed in the vacuum chamber is filled with evaporation material 2, such as pure selenium, and a heater 3 A photosensitive layer is formed by vacuum deposition on the surface of the cylindrical aluminum substrate 5, which is deposited on the support shaft 4 with a spacer 6 interposed therebetween. The spacer 6 is hollow and hermetically sealed, and a heat medium 7 is sealed in the hollow space. When the inside of the vacuum chamber is evacuated, the spacer 6 expands due to the pressure difference between the inside and outside of the spacer, and the contact surface between the inner support shaft 4 and the outer base 5 deforms to match the shape of the other surface. Completely in contact with the other person's face. Heat transfer from the substrate to the support shaft during vapor deposition is carried out by conduction between the substrate 5 and the spacer 6 and between the support shaft 4 and the spacer 6, and by convection in the spacer space. 4, the spacer 6, and the base 5 are pressed from the spacer side with a pressure of about 1 atm and are in close contact with each other, so the heat conduction between them is very good, and the heat transfer between the support shaft 4 and the base 5 is very good. is carried out quickly, making it possible to control temperature with good thermal responsiveness. Figure 2 shows the substrate temperature at each point in time during vapor deposition when a carrier transport layer, a carrier generation layer, and a surface coating layer were sequentially formed on a substrate by vacuum vapor deposition, and the solid line indicates the temperature of the substrate at that time. This is the case using the example device, and the dotted line is the case using the conventional device. In either case, the substrate temperature begins to rise at time A when the heater of the evaporation source is turned on, and at time B when carrier transport layer evaporation begins.
The heat of evaporation of the vapor deposition material is also added, and the temperature rises rapidly.

The substrate temperature reached its maximum at time C, when the carrier transport layer had finished evaporating and the carrier generation layer had begun to evaporate, but in the case of conventional devices, the temperature at this point reached 90° C. or higher, which caused many problems. On the other hand, in the case of the apparatus of the present example, although the initial temperature at the start of the vapor deposition operation was 10° C. higher than the conventional temperature, it was able to be maintained at 80° C. or lower. Increasing the temperature of the substrate at the initial stage of vapor deposition is preferable because it makes it possible to strengthen the adhesion between the substrate and the selenium layer.

〔Effect of the invention〕

According to the present invention, in an apparatus for manufacturing a selenium photoreceptor for electrophotography using vacuum evaporation, the temperature of the layer during vacuum evaporation can be quickly controlled within a narrow control range by interposing a spacer between the support and the substrate. This made it possible to reduce the occurrence of quality problems such as crystals in the photosensitive layer. Additionally, it has become possible to use small-diameter, thin-walled aluminum tubes with low heat capacity in the photoreceptor, contributing to cost reduction. moreover,
By changing the thickness of the spacer, great effects can be obtained, such as making it possible to manufacture photoreceptors of various diameters without replacing the support shaft.

4. Detailed Description of the Invention Fig. 1 is a conceptual cross-sectional view of the inside of a vacuum chamber of an apparatus according to an embodiment of the present invention, and Fig. 2 shows various views during vacuum evaporation in an apparatus according to an embodiment of the present invention and a conventional example. FIG. 3 is a diagram showing the relationship between time and substrate temperature.

4... Support shaft, 5... Cylindrical conductive base, 6
・・・S Figure 1 Figure 2

Claims (1)

[Claims] 1) A cylindrical conductive substrate is mounted on a temperature-controllable support shaft provided in a vacuum chamber, and a cylindrical conductive substrate is placed on the cylindrical conductive substrate whose temperature is controlled to a predetermined temperature via the support shaft. In an apparatus for manufacturing a selenium photoreceptor for electrophotography in which a photosensitive layer is formed by vacuum-depositing at least one of selenium and a selenium alloy, an air is formed between the cylindrical conductive substrate and the support shaft at atmospheric pressure. Manufacture of a selenium photoreceptor for electrophotography characterized by interposing a hollow spacer with a deformable structure that expands due to a pressure difference when the surroundings are sealed and evacuated to fill the gap between the two. Device. 2) A manufacturing apparatus for a selenium photoreceptor for electrophotography according to claim 1, wherein a heating medium is enclosed in a hollow spacer.