JPH03140990A - Electrophotographic process - Google Patents

Abstract

PURPOSE:To maintain excellent image quality, to miniaturize a device and to accomplish low power consumption by using light having peak wavelength within a specified range as destaticizing light in an electrophotographic process in which a selenium photosensitive body is used. CONSTITUTION:The electrophotographic process is performed while rotating the photosensitive body 1 for electrophotography provided with a photosensitive layer made of selenium-based alloy on a conductive substrate, and destaticizion is performed with the light having the peak wavelength within the range of >=560nm and <=590nm by a destaticizing device 8. As a result, the complete destaticization is performed without causing large optical fatigue that is a problem in practical use on the selenium photosensitive body 1, and the variation of dark or the increase of residual potential is a little even when the electrophotographic process is repeated, then the electrostatic charging potential is a little, then the electrostatic charging potential at the time of developing is kept nearly constant. Thus, the excellent image quality is maintained, a necessary space is made small and the power consumption is made low.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electrophotographic process, and more specifically to an electrophotographic photoreceptor (hereinafter also simply referred to as a selenium photoreceptor) having a photosensitive layer made of a selenium alloy. This invention relates to optical charge removal in the electrophotographic process in electrophotographic devices such as electrophotographic copying machines, laser printers, and facsimile machines.

[Conventional technology]

In an electrophotographic apparatus, it is required that the obtained images maintain good image quality. During image formation, the photoreceptor is charged and exposed to at least two images.

Although the electrophotographic process consisting of development, transfer, cleaning, and photostatic discharge steps is repeated, there is no change in density.
In order to continuously obtain good images without background smudges, it is necessary that the charged potential during development be constant, and that the residual potential is sufficiently removed in the photostatic charge removal process so that it does not increase. It is important that dark decay does not change due to photofatigue caused by

For this reason, relatively short wavelength light (
For example, a method using a cold cathode tube with a wavelength of 540 nm,
Static eliminator with peak wavelength over 600nm and 6001m
A method (Japanese Unexamined Patent Publication No. 57-212458) is known in which a static eliminator having a peak wavelength is used in combination with the following.

[Problem to be solved by the invention]

When a cold cathode tube is used as a static elimination light source, there is a problem in that the wavelength of the static elimination light changes depending on the temperature, making it difficult to maintain appropriate and stable static elimination.

Further, since it requires accessory equipment such as a converter, the device becomes large-sized, consumes a large amount of power, and has the disadvantage of increasing running costs.

When using a combination of two static eliminators with different wavelengths, for example, an LED array with a wavelength of 550 m and an LED array with a wavelength of 600 m.
When using in combination with a nm to 700 nm LED array, it is difficult to select the light intensity of each to obtain the optimal static elimination effect, and space is required for two static elimination light sources, making the device large. is unavoidable.

This invention was made in view of the above points, and
In electrophotographic equipment that uses a selenium photoreceptor, it is possible to obtain a sufficient static elimination effect to maintain good image quality without any practical problems, and to contribute to the miniaturization and lower power consumption of electrophotographic equipment. The challenge is to provide a photographic process.

[Means to solve the problem]

According to the present invention, the above-mentioned problem can be solved by using an electrophotographic photoreceptor having a photosensitive layer made of a selenium alloy on a conductive substrate, which is charged with at least one image of exposure, development, transfer, cleaning, and photostatic discharge. This problem can be solved by using light having a peak wavelength within a range of 560 nm or more and 590 nm or less for the optical charge removal in an electrophotographic process that repeatedly performs the above.

[Effect]

By removing static electricity using light with a peak wavelength within the range of 560 nm or more and 590 nm or less, it is possible to perform sufficient static electricity removal without causing significant optical fatigue on the selenium photoreceptor, which would be a practical problem. Even if the process is repeated, there is little variation in dark decay or increase in residual potential, and the charged potential during development can be kept almost constant, making it possible to maintain good image quality. Furthermore, only one static eliminating light source is required, so the required space is small and power consumption is low.

〔Example〕

A photoreceptor was prepared by vacuum-depositing Se-hes alloy with an As concentration of 36% by weight to a thickness of 60 μm on the outer surface of an aluminum alloy tube.

An electrophotographic process is performed on this photoreceptor while rotating the photoreceptor 1 in the direction of the arrow in the arrangement shown in FIG. The dark decay up to the developing device 4 was measured. FIG. 1 shows the relationship between the wavelength of the static eliminating light, dark decay, and residual potential when the light intensity of the static eliminating light is set to 20 times the half-attenuation exposure amount of the photoreceptor 1, and the wavelength is varied from 500 nm to 700 nm.

As seen in FIG. 1, as the wavelength of the static eliminating light becomes shorter, the residual potential becomes larger, and as the wavelength becomes longer, the dark decay becomes larger. Therefore, in the case of reversal development, for example, the density of the image obtained decreases as the wavelength of the static eliminating light becomes shorter, and conversely, as the wavelength of the neutralizing light becomes longer, scumming occurs. As a result of investigating dark decay and residual potential to obtain images of good image quality with no practical problems, the dark decay was 30V or less and the residual potential was 3QV or less in both cases of normal development and 9 reversal development. . As a result, it can be seen from FIG. 1 that the optimum wavelength of the static eliminating light is between 560 nm and 590 nm. Based on this result, for the above selenium photoreceptor, L with a wavelength of 570 nm was used as the static elimination light.
Light from the ED array (the amount of light is 2 times the half-attenuation exposure of the photoreceptor)
When a continuous image output test was carried out using a copying machine using an electrophotographic process using 0x), no problems occurred in image quality over a wide environmental temperature range of 5°C to 40°C.

〔Effect of the invention〕

According to this invention, 560 nm or more 59
Light having a peak wavelength within a range of 0 nm or less is used. By using such an electrophotographic process using static-eliminating light,
It is possible to obtain an electrophotographic apparatus that can maintain good image quality without causing any practical problems even when images are repeatedly produced, and furthermore, the apparatus can be made smaller and consume less power.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between the wavelength of static eliminating light, dark decay, and residual potential, and FIG. 2 is a conceptual diagram showing an embodiment of the arrangement of the electrophotographic process according to the present invention. 1 photoreceptor, 2 charger, 3 exposure, 4 developer, 5 transfer device, blade, static eliminator.

Claims (1)

[Claims] 1) In an electrophotographic process in which an electrophotographic photoreceptor having a photosensitive layer made of a selenium-based alloy on a conductive substrate is repeatedly subjected to at least charging, image exposure, development, transfer, cleaning, and photostatic discharge, the photoreceptor is 560nm for static elimination
An electrophotographic process characterized by using light having a peak wavelength within a range of 590 nm or less.