Single-layer type electrophotosensitive material and image forming apparatus using the same

Abstract

The present invention provides a single-layer type electrophotosensitive material comprising a conductive substrate and a photosensitive layer formed on the conductive substrate, wherein the photosensitive layer contains a phthalocyanine compound as an electric charge generating material, a hole transferring material and an electron transferring material in a binder resin, and that a difference in absolute value between a plus polarity sensitivity and a minus polarity sensitivity measured under the conditions of an exposure wavelength of 780 nm and an exposure energy of 1.0 μJ / cm2 is not more than 500312 V, and a reversal development type digital image forming apparatus using the electrophotosensitive material, which does not include a charge neutralizing step.

Description

[0001]This application claims priority to Japanese Patent Application No. 1999-302914, filed on Oct. 25, 1999, the disclosure of which is incorporated by reference in its entirety.BACKGROUND OF THE INVENTION[0002]The present invention relates to a single-layer type electrophotosensitive material which is used in digital image forming apparatuses such as electrophotosensitive copying machine, facsimile and laser beam printer, and a digital image forming method using the same.[0003]More particularly, the present invention relates to a single-layer type electrophotosensitive material, which does not generate a memory image even when using in a reversal development type digital image forming apparatus including no charge neutralizing step, and a reversal development type digital image forming method using the same, which does not include a charge neutralizing step.[0004]Recently, an organic photosensitive material has widely been used because of its easy production, low cost, wide range...

AI Technical Summary

Benefits of technology

The solution effectively reduces exposure and transfer memories, preventing the generation of memory images even in systems without a charge neutralizing step, by ensuring balanced hole and electron transfer, thus improving image quality.

Problems solved by technology

However, the following problems such as generation of a memory image occur when using a conventional electrophotosensitive material in a reversal development type digital image forming apparatus.

However, on-off timing of the transfer voltage is very difficult and portion to be applied directly to the photosensitive material is often generated with respect to front / rear portions of the transfer medium.

However, in case where the sensitivity of the positively charging single-layer type photosensitive material to the negative polarity is drastically inferior (mobility of the electron transferring material is very small) or the photosensitive material is used in the image forming apparatus including no charge neutralizing step, negative space electric charges are not sufficiently neutralized and a reduction in potential is caused by an influence of space electric charges even if the photosensitive material is positively charged in the following charge step.

Furthermore, a difference in sensitivity appears in the development step, thus causing such problems that said portion turns into black in the image (memory image).

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