Ricoh Company, Ltd.

Toshio Shimazaki

Hiromi Takada

Hideo Aoki

Keiji Okamoto

Hideaki Sugata

Hiroshi Hosokawa

Nobuyuki Satoh

Hideaki Mochimaru

Hiroshi Ono

Yoshiaki Tanaka

Nobuhiro Makita

Yasuhiro Sagawa

Takami Suzuki

Masayoshi Miyamoto

Hiroyuki Idenawa

Michihito Ohashi

Takeshi Motohashi

Tadaaki Kanno

Hajime Kanda

Takundo Isobe

Hisao Ishizu

Kohji Amanai

Kazuyuki Futami

Ken-ichirou Asada

Takanori Yamaki

Tetsuya Nakao

Takahiro Yagisita

Tomoo Sankoda

In an image forming apparatus of the present invention including a plurality of photoconductive drums arranged side by side, each photoconductive drum is configured to allow its opposite end portions in the main scanning direction to be adjusted in maximum eccentricity position in the direction of rotation independently of each other. The maximum eccentricity positions of the drums are capable of being matched in phase to each other in the direction of rotation at each of opposite end portions.

Photoconductive element unit including support portions configured to adjust eccentricity positions for an image forming apparatus

A color image forming apparatus for superimposing images formed on a plurality of photoconductive elements onto a copy sheet includes a sensor for reading a transfer member and a positional deviation detecting pattern formed on the transfer member, a memory for storing information relating to an area having no roughness, such as a scar, on the transfer member, a detector for detecting the area having no roughness on the basis of a signal read by the sensor and for causing the memory to store the information relating to the area, and a color deviation corrector for correcting color deviation on the basis of the signal generated by the sensor reading the positional deviation detecting pattern. The positional deviation detecting pattern is formed at an area of the transfer member having no roughness.

Color image forming apparatus with positional deviation detecting

An electrostatic photographic image forming apparatus for forming an electrostatic image on a photosensitive member by the light beam from a writing system and transferring to a transfer paper the image which has been made visible by a development apparatus. A shutter or a toner contamination preventive means is provided at the space defining an optical path extending between the photosensitive member and the lens of the writing system nearest to the photosensitive member.

Toner contamination preventive means

An electrostatic photographic apparatus includes a photosensitive drum and a fixing device composed of a pair of rollers pressure-contacted with each other over a predetermined nip width, in which a toner image formed on the photosensitive drum is transferred onto a lower surface of a transfer paper transported over an upper portion of the photosensitive drum while contacting therewith and is fixed by a nip portion of the rollers of the fixing device, an inlet end of the nip portion is disposed on a curve of a cross section of the transfer paper when the latter is warped with a radius of curvature smaller than a radius of curvature of cross section of a transfer paper having stiffness smallest among other transfer papers usable in the apparatus when the transfer paper of the smallest stiffness is supported at its rear end horizontally at a point at which the transfer paper leaves the photosensitve drum while allowing the other portion thereof to be drooped freely by gravity, a tangential line of the rollers at a center of the nip portion being substantially coincident with a tangential line of the curve, and guide member having a lower guide surface convexed upwardly is arranged along the curve between the separating point of the transfer paper from the photosensitive drum and the inlet end of the nip portion.

Transfer paper guide device for an electrostatic photographic apparatus

A laser printer or like electrostatic recording apparatus of the type developing an electrostatic latent image provided on a photoconductive drum by toner which is conveyed by a developing roller. Various devices of the apparatus including the photoconductive drum and developing roller are separated into an upper and a lower unit which are openable away from each other. A photoconductive drum assembly including the photoconductive element and a developing assembly including the developing roller are individually detachable from a body of the apparatus. Various measures are taken to enhance stable and safe operation, miniaturization, easy maintenance, operability, service life, and image quality.

Electrostatic recording apparatus

A compact laser printer has an up-side down arrangement of components within a machine housing. That is, an optical writing unit is disposed below a rotatably supported photosensitive drum and an image transferring unit is disposed above the photosensitive drum with a developing unit disposed substantially in a side-by-side relationship with the photosensitive drum. A paper feed cassette is located below the optical writing unit when detachably set in position and a paper transportation path extends from the supply end of the paper feed cassette around the developing unit generally in the shape of 'U.' The machine housing has a pivotally movable portion which may be pivotted open and closed. The photosensitive drum and/or one of a pair of registration rollers may be mounted on the pivotally movable portion.

Compact image recording apparatus having an up-side down structure

A recording head of a current application type serial printer is provided with two independent recording electrode groups on both sides of its tip. The angle of contact of the recording head with a platen of the printer is switched between a forward printing stroke and a backward printing stroke of a carrier so that, usually, the electrode group on the right-hand side of the recording head is used during the forward printing stroke, and the electrode group on the left-hand side during the backward printing stroke.

Head rotating mechanism for a printer

Growing community of inventors

Tokyo, Japan

Toshio Shimazaki