Kyocera Corporation

Other

Kazumasa Ohkawa

Hiroshi Ito

Takao Kawamura

Naooki Miyamoto

Hitoshi Takemura

Kokichi Ishibitsu

Hisashi Higuchi

Hiroshi Hayashi

Shoji Mayama

Yoichiro Shimono

The present invention relates to an improvement of an electrophotographic sensitive member comprising an amorphous silicon photoconductive layer and an amorphous silicon carbide surface layer formed on said amorphous silicon photoconductive layer. An electrophotographic sensitive member with amorphous silicon as a photoconductive layer has been already practically used and a quantity thereof produced has been on the increase year by year. In this sensitive member, as a rule, in order to increase a surface hardness, a surface layer formed of amorphous silicon carbide has been formed. An electrophotographic sensitive member with such two layers as the fundamental layer structure improved in charge acceptance, residual electric potential, photosensitivy and the like by forming a carrier blocking layer containing boron, oxygen, nitrogen and the like in a quantity within a desired range between a substrate for use in a sensitive member and the amorphous silicon photoconductive layer has been provided. However, the above described sensitive member has shown problems in that a sufficiently high initial electric potential can not be obtained yet and an electric potential decayed until the development from the charging by a corona discharge to give the initial electric potential to the surface, that is a dark decay, is large, so that the sufficiently high surface electric potential can not be obtained in the development. In view of the above described, it is an object of the present invention to provide an electrophotographic sensitive member which is improved in dark decay characteristics and capable of obtaining a high electric potential at a position where the development is conducted.

Layer electrophotographic sensitive member comprising morphous silicon

The present invention relates to an electrophotographic sensitive member, in particular to a divided function type electrophotographic sensitive member formed of amorphous silicon and amorphous silicon carbide capable of particularly widening an optical band gap range to heighten an optical sensitivity. Stabilized operation characteristics and durability are required for an electrophotographic sensitive member drum carried on instruments such as a high-speed copying machine and a laser beam printer. As for these requirements, hydrogenized amorphous silicon is being watched with interest from the viewpoints of superior abrasion resistance, heat resistance, anti-pollution property, optical sensitive characteristic and the like. However, even multi-layer type sensitive member and a divided function type sensitive member, which have been known as an electrophotographic sensitive member formed of hydrogenized amorphous silicon, have shown problems in that in the case where they are used in the high-speed copying, a residual image, in which the preceding image remains without being completely removed by an optical memory effect and appears again with the formation of the subsequent image, occurs, and an image exposure per one time of copying is reduced by the high-speediness, whereby the sufficient optical attenuation can not be obtained and the potentiality of the sensitive member corresponding to a shading contrast of a manuscript can not be sufficiently increased, so that a background smearing is produced. The present invention aims at the obtainment of an electrophotographic sensitive member capable of solving such problems and provides an electrophotographic sensitive member capable of heightening an optical sensitivity over a wide wavelength range to obtain sufficient optical attenuation characteristics, whereby being suitable for the high-speed copying.

Electrophotographic sensitive member

The present invention relates to an electrophotographic sensitive member, in particular to an electophotographic sensitive member, in which a residual potential is reduced and a background smearing is prevented from being produced, and further to an electrophotographic sensitive member capable of carrying out a high-speed copying suitable for a semiconductor laser beam printer. A photosensitive member used in instruments, such as super-high-speed coying machine and laser beam printer, is used for a long time at a high-speed, so that the stability and durability are required for the operation. To this requirement, amorphous silicon hydride has been watched with interest in view of heat-resistance, abrasion-resistance, anti-pollution, photosensitive characteristic and the like. However, also a multi-layer type photosensitive member or a separated function type photosensitive member, which has been known as an electrophotographic sensitive member formed of this amorphous silicon hydride, has shown a problem of residual image that the preceding image is not completely removed to be remained by an optical memory effect and appears again in the formation of the following image when it is used in the high-speed copying, a problem that the oscillation wavelength of laser beam is close to a near-infrared range, so that an amorphous silicon photosensitive member on the light-receiving side is inferior in photosensitive characteristic when the amorphous silicon photosensitive member is carried on the laser beam printer, and a problem that the surface potential is reduced. The present invention aims at the obtainment of an electrophotographic sensitive member from which the above described problems are eliminated.

Electrophotographic sensitive member with amorphous silicon carbide

Growing community of inventors

Yohkaichi, Japan

Kazumasa Ohkawa