Minolta Camera Kabushiki Kaisha

Isao Iizaka

Toshio Yamamoto

Osamu Miyamoto

Takashi Hikosaka

Hiroshi Okamoto

Tetsuya Yamada

Shigemitsu Shimizu

Fumitoshi Atsumi

Shigemitu Shimizu

A photoreceptor charge control arrangement to be employed for electrophotographic copying apparatuses wherein a specific circumferential portion on a uniformly charged photoreceptor is first exposed by a referenced exposure source to a specific amount of exposure and successively, the surface potential of the circumferential portion mentioned above is detected either at the relative position immediately before a position for an imagewise light exposing station or at the position juxtaposing the position of the station mentioned above, so that the successive comparison of the surface potential thus detected with a fixed reference is capable of effectively providing an appropriate control signal which can be employed to compensate the amount of exposure of the exposure source, irrespective of the surface condition of the photoreceptor.

Electrophotographic density control

An electrostatic latent image transfer type copying apparatus which has a photoconductive member, a system for forming an electrostatic latent image on the photoconductive member, an image transfer system for conducting transfer material having an insulating dielectric layer coated over an electrically conductive layer into contact with the photoconductive member for transferring the latent image onto said transfer material, a transporter for the transfer material to transport it along a predetermined path to the image transfer system, a member such as a relatively sharp edge member like a cutter provided along the path and below which the insulating dielectric layer side of the transfer material passes, and an insulating member provided adjacent the sharp edge member for preventing the surface of transfer material from contacting the sharp edge member as the transfer material is transported, whereby the contact of the sharp edge member with the surface of transfer material which causes frictional charging on the transfer material is substantially prevented.

Electrostatic latent image transfer type copying apparatus

A liquid type developing apparatus includes a developing liquid chamber containing a developing liquid comprised of toner and an organic solution. A recording sheet having an electrostatic latent image on its surface passes between a pair of upper and lower electrically conductive electrode members arranged so that at least one of such members contacts the developing liquid. An electric power source is connected to one of the electrode members for impressing a bias voltage thereto, such one member being arranged in non-contacting relationship with the chamber, and the other of such members being arranged in electrically conductive relationship with the tank, whereby any leakage of the impressed voltage due to attraction of the toner to the members, the tank or to bearings provided for the members, is substantially avoided.

Liquid type developing apparatus

Apparatus for improving the quality of images obtained in an electrostatic latent image transfer type copier according to which there are provided electrical circuits permitting escape or neutralization of charges which may be produced in copy paper during its transport through a photocopying machine and could cause smudging or elimination of required image portions in developed copy paper carrying the image of a document or similar material. In the disclosed embodiment, the electrical circuits maintain each of the rollers of pairs of copy sheet transporting rollers at an equal potential.

A dielectric layer of copy paper is brought into contact with an electrostatic latent image bearing surface of a photosensitive plate by a first roller having an electric resistance value substantially higher than the rear face resistance value of the copy paper, the photosensitive plate having on its front face a dielectric layer for forming the latent image thereon and driven by a grounded roller. An electrically conductive lining element of the copy paper is substantially grounded by an electrically conductive second roller to transfer the electrostatic latent image by air breakdown discharge under the influence of the first and second rollers. The gap between the photosensitive plate and the copy paper has a width for air breakdown discharge according to Paschen's law.

Growing community of inventors

Shinshiro, Japan

Isao Iizaka