Ricoh Company, Ltd.

Eiji Shimojo

Takeshi Uchitani

Masanori Kawasumi

Masahiko Satoh

Eisaku Murakami

Yoshiyuki Kimura

Shunichi Hashimoto

Shin Kayahara

Hideki Zemba

Yuji Suzuki

Hirokazu Ishii

Satoshi Takano

Hiroshi Saitoh

Itaru Matsuda

Ryoh Tanoue

Noboru Onodera

Hidenori Nihei

Yuji Arai

Hiroshi Ono

Masami Tomita

Toshio Koike

Ken Amemiya

Takatsugu Fujishiro

Haruji Mizuishi

Takuzi Yoneda

Yutaka Narita

Tokuya Ojimi

An image forming apparatus in which a visible image is transferred to a transfer material includes a pre-transfer exposing unit that makes only a portion of a latent image carrier that corresponds to a leading edge of the transfer material expose, and a transfer-bias applying unit that applies a bias for transferring the visible image. The transfer-bias applying unit starts applying the bias to the transfer material, at least step-by-step, when a predetermined time is passed from a point of time at which the leading edge of the transfer material comes into a contact with the latent image carrier by controlling the pre-transfer exposing unit and a bias applying timing of the transfer-bias applying unit.

Image forming apparatus with improved separability of transfer material

A transfer device is provided for an image forming apparatus designed such that toner images formed on a plurality of image bearing members are transferred one over another on a transfer body disposed in contact with each of the image bearing members with predetermined pressure and thus a toner image in two or more colors is formed on the transfer body. The transfer device includes a pressure varying mechanism which is capable of separating the transfer body from at least some of the image bearing members, and capable of varying transfer pressure between the image bearing members and the transfer body in contact with said image bearing members.

Transfer device and image forming apparatus

A method and an apparatus of controlling a charge voltage including the steps of applying, charging, detecting, and determining. The applying step applies an application voltage having a direct-current voltage and an alternating-current voltage superimposed onto the direct-current voltage to a charge-applying member to charge a charge carrier. The changing step charges the alternating-current voltage of the application voltage. The detecting step detects an alternating current flowing through the charge carrier when the charge-applying member applies the application voltage to the charge carrier. The determining step determines a value of the alternating-current voltage of the application voltage based on at least two alternating currents detected by the alternating-current detector.

Method and apparatus for image forming capable of effectively performing a charging process

A conductive member, including a long conductive supporting body, an electrical resistance adjusting layer, disposed on the outer circumferential surface of the conductive supporting body and having a reduced diameter section at either end, and a pair of gap maintaining members which are respectively fitted onto said reduced diameter sections of the electrical resistance adjusting layer. The outer circumferential surfaces of the gap maintaining members have a height differential with respect to the outer circumferential surface of the electrical resistance adjusting layer, in such a manner that when abutted against an image carrier, a prescribed gap is formed between the outer circumferential surface of the image carrier and the outer circumferential surface of the electrical resistance adjusting layer. An interval between the end faces of the electrical resistance adjusting layer and the faces of the gap maintaining members opposing the end faces satisfies a predetermined relationship.

Conductive member, and charging roller, process cartridge and image forming apparatus using same

A charging member, which can be provided in a process cartridge and/or in an image forming apparatus, includes a conductive supporting member, an electrical resistance control layer formed on an outer circumferential surface of the conductive supporting member, and a nonconductive gap retaining member configured to retain a gap between the conductive supporting member and an image carrying member closely disposed to each other to have a constant distance. At least a portion of the nonconductive gap retaining member is mounted on the electrical resistance control layer at both ends of the conductive supporting member, and a circumference of the nonconductive gap retaining member projects from the electrical resistance control layer. An amount of projection of the gap retaining member from the electrical resistance control layer decreases as the gap retaining member tapers in a direction toward a center of an image formation region.

Charging member, process cartridge including the same, and image forming apparatus including the same

A charge apparatus charges by uniformly superimposing an alternate current bias voltage with a fixed frequency over a direct current bias voltage as the charge bias voltage on a photosensitive member. An exposure apparatus exposes the surface of the charged photosensitive member based on image data, and writes a latent image, and a developing apparatus supplies toner to and makes visible the latent image formed on the surface of the photosensitive member. A transfer apparatus transfers the visible image on the photosensitive member to a transfer medium, and a cleaning apparatus cleans the surface of the photosensitive member after transfer.

Image forming apparatus that charges a photosensitive member by superimposing an alternate current bias voltage on a direct current bias voltage as the charge bias voltage

Image forming apparatus with improved separatability of transfer material

Growing community of inventors

Tokyo, Japan

Eiji Shimojo