JPH0117573B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor with excellent development characteristics.

Conventionally, as a photoreceptor used for electrophotography, a functionally separated photoreceptor is known, which has high sensitivity to long wavelength light such as a semiconductor laser as an exposure light source, and as shown in Figure 1, it is a functionally separated photoreceptor. transport layer 1
(Se), a charge generation layer 2 (SeTe), and a conductive substrate 3. Since the SeTe layer 2 on the surface side has a high Te concentration to increase exposure sensitivity, the resistance value of this SeTe layer 2 is low, and the development bias voltage is
The developer was not effectively applied to the SeTe layer 2, and the developer was not sufficiently attached to the surface of the SeTe layer 2, making it impossible to obtain a clear reproduced image.

The present invention has been made in view of the above, and an object of the present invention is to provide an electrophotographic photoreceptor that has excellent developability and can provide clear reproduced images.

This purpose includes: a conductive substrate; a first charge transport layer made of selenium formed on the conductive substrate; and a charge generation layer made of selenite formed on the first charge transport layer. , an electrophotographic photoreceptor in which reversal development involving uniform charging, negative exposure, and application of a developing bias voltage is performed, wherein a second film made of simple selenium and having a thickness of 10 μm or less is formed on the charge generation layer. This is achieved by an electrophotographic photoreceptor having the following five characteristics: a charge transport layer is formed thereon.

Preferred embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a configuration diagram of an embodiment of the present invention, in which the same parts as in FIG. 1 are given the same reference numerals. In FIG. 2, 4 is a second charge transport layer (insulating layer). This insulating layer 4 must have a high resistance so that a bias voltage can be applied effectively during development, and must be able to efficiently transport both electrons and holes, which are light carriers generated during exposure. is necessary. A material that meets these requirements has good energy matching at the interface with the underlying SeTe layer, has almost the same transport properties for electrons and holes, and is resistant to short wavelength light (wavelength of 550 μm or less). The most suitable material is selenium (Se), which has excellent charge generation ability.

Figures 3a and 3b show Se, which is the material of the insulating layer 4, respectively.
This shows the optical attenuation characteristics under positive and negative corona charging of the material layer. As is clear from the figure, it has the same photoconductivity regardless of whether it has positive or negative polarity, which indicates that it has the ability to effectively transport both electrons and holes. show.

FIG. 4 shows the layer thickness dependence of the half-reduced exposure sensitivity of the insulating layer 4, and the subscript number indicates the layer thickness of the insulating layer 4. As is clear from the figure, when the layer thickness is less than 5 μm, He−Ne
When the layer thickness is 10 μm or less with respect to laser light, the exposure sensitivity to semiconductor laser light is hardly impaired.

Using the photoreceptor shown in FIG. 2, negative exposure was performed using a semiconductor laser as an exposure source, and reversal development was performed. As a result, a high quality reproduced image without background smear was obtained.

As is clear from the above description, in the electrophotographic photoreceptor according to the present invention, the photoreceptor surface layer, which is uniformly charged before exposure, has an excellent charge retention function, and the insulating layer, which is the photoreceptor surface layer, Since electrical charges are well preserved on the surface, it is possible to perform reversal development after negative exposure, reducing optical fatigue of the photoreceptor.
This has the advantage that the light emission time of the laser light source, which is the exposure source, can be shortened, and the repeatability characteristics can be stabilized and the lifespan can be extended.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the configuration of a conventional photoreceptor, Fig. 2 is a diagram showing the configuration of an embodiment of the present invention, and Figs. 3a and b are diagrams showing the light attenuation characteristics under positive and negative corona charging of the selenium layer. , FIG. 4 is a diagram showing the layer thickness dependence of the half-reduced exposure sensitivity of the insulating layer. 1: First charge transport layer, 2: Charge generation layer, 3:
Conductive substrate, 4: second charge transport layer.

Claims (1)

[Claims] 1. A conductive substrate 3; a first charge transport layer 1 made of selenium formed on the conductive substrate 3; and a first charge transport layer 1 made of selenium formed on the first charge transport layer 1. An electrophotographic photoreceptor comprising: a charge generation layer 2 consisting of a charge generation layer 2; the electrophotographic photoreceptor is subjected to uniform charging, negative exposure by laser irradiation, and reversal development involving application of a developing bias voltage; A photoreceptor for electrophotography, comprising: a second charge transport layer 4 made of simple selenium with a diameter of 10 μm or less.