JPS60203978A - Image forming device - Google Patents

Abstract

PURPOSE:To enable formation of an always good and stable image by irradiating light contg. UV light on a photosensitive material consisting of a prescribed material and forming a non-image part. CONSTITUTION:A non-image part is formed on a selenium-tellurium photosensitive body 1 when the body 1 is irradiated by the light including UV light by a mercury lamp 3 upon completion of an image forming process. Even if the tellurium oxide film on the surface of the body 1 is chipped by rubbing with a cleaning member, the growth of the tellurium oxide layer is accelerated by such irradiation, by which dropout of the image is prevented and the always good and stable image is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus of a type that charges and exposes a selenium-tellurium photoreceptor to form an electrostatic latent image and then develops it with a developer. - In Maki's image forming apparatus using a tellurium-based photoreceptor, when cleaning the photoreceptor, a cleaning member is used to remove residual developer on the photoreceptor, causing scratches on the surface of the photoreceptor. It has the disadvantage of being

An object of the present invention is to eliminate this drawback and provide an image forming apparatus of the above type that can always form good and stable images.

A feature of the present invention is that in this type of image forming apparatus using a selenium-tellurium photoreceptor, the photoreceptor is irradiated with light containing ultraviolet light when an image is not being formed.

FIG. 1 is a schematic sectional view of an embodiment in which the present invention is applied to an electrophotographic subject, in which 1 is a selenium-tellurium photoreceptor drum, 2 is a charging device, 3 is a low-pressure mercury lamp, and 4 is a developing device. , 5 is a transfer/separation device, 6 is a cleaning device for the photoconductor, 7 is a static eliminator, 8 is a transferred recording paper conveyance belt, 9 is a fixing device, 10 is a mirror for exposing the image to the photoconductor, 11.12 is a A paper feed roller, 13 is a paper feed cassette, and 14 is a paper discharge roller.

Except for the low-pressure mercury lamp 3, the configuration and operation of the copying machine described above are well known and will not be described in detail here.

A series of images l-F from each of these devices, excluding mercury lamp 3
? The ram 1 continues to rotate as it is, and the mercury lamp 3 lights up at this time. As a result, ultraviolet light emitted from the mercury lamp 3 is irradiated onto the photoreceptor. After this state is maintained for 30 seconds (unless the image forming process starts again), the mercury lamp 3 is turned off and the rotation of the photosensitive drum 1 is stopped. The mercury lamp 3 is turned on during the post-rotation of the photoconductor.Irradiation of the photoconductor with ultraviolet light in this manner eliminates white spots in the image that occur in areas corresponding to scratches on the surface of the photoconductor. It was found that the above configuration can prevent such white spots from occurring.The reason why ultraviolet light is effective against white spots is not clear. It is estimated as follows.

In other words, white spots occur because the tellurium oxide film on the surface of the Cele/-Tellurium photoreceptor is scraped off by the rubbing of the cleaning member against the photoreceptor, and the dark decay of the potential at that portion increases. It is thought that the growth of this tellurium oxide film is promoted by irradiation with ultraviolet light, thereby eliminating the white spots.

As another example, in a copying machine having the same configuration as above,
After pressing the copy button, the mercury lamp 3 is turned on as the photosensitive drum 1 rotates for a certain period of time (5 to 10 seconds) before the start of the image forming process, and then the image forming process is started. Good too. Finally, the mercury lamp 3 may be turned on during the pre-rotation of the photoreceptor drum.

As yet another embodiment, when image formation is performed several times in succession, the mercury lamp 3 may be turned on only at intervals between image formations. Instead of using the low-pressure mercury lamp 3 (preferably a light source containing ultraviolet light with an energy distribution ratio of 10 or more) as the ultraviolet light source, any light source containing ultraviolet light, such as a black light, may be used. The position of this ultraviolet light source is not limited to the position shown in FIG. 1, but may be any position where the light hits the photoreceptor.

As explained above, according to the present invention, by irradiating the selenium-tellurium photoreceptor with ultraviolet light during non-image formation, it is possible to prevent scratches caused by the photoreceptor in an image forming apparatus using the photoreceptor. The white spots that often occur are effective in preventing this phenomenon.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of an electrophotographic copying machine embodying the present invention. 1: Selenium-tellurium photoconductor drum, 2: Charging device, 3: Low pressure mercury lamp, 4: Developing device, 5 Transfer/separation device, 6: Cleaning device, 7: Static eliminator, 8: Conveying device, 9: Fixing Device, 10: Image exposure reflection mirror, 11: Registration roller, 12: Paper feed roller, 13: Transfer paper, 14: Paper discharge roller. Figure 1

Claims (1)

[Claims] 1. In an image forming apparatus that forms an electrostatic latent image using a selenium-tellurium photoreceptor and develops it with a developer, ultraviolet light is applied to the photoreceptor during non-image formation. An image forming apparatus characterized by irradiating. 2. The image forming apparatus according to claim 1, which irradiates light containing ultraviolet light with an energy fraction of 10 or more.