Sharp Kabushiki Kaisha Corporation

Takayuki Ohno

Ayumu Oda

Norio Tomita

Toshio Yamanaka

Yoshikazu Harada

Fumio Shimazu

Yoshinobu Tateishi

Kiyoshi Toizumi

Hiroshi Tachiki

Nobuo Manabe

Yuhi Akagawa

Atsuyuki Katoh

Yasuhiro Ono

Takasumi Wada

Kouichi Yamauchi

Hiromu Yoshimoto

Takuya Abe

Mitsuyoshi Terada

Keizo Fukunaga

Atsushi Ueda

Kyosuke Taka

Hideaki Kadowaki

Masahiko Fujita

Osamu Fujimoto

Masaya Asakawa

Hirokazu Fujita

Hidenobu Mandai

Kouzou Yamaguchi

Masanobu Yamamoto

Hiroshi Yamamoto

Takahisa Narikiyo

Masaki Saka

Atsuo Nakao

Kenzo Ohkubo

An optical scanning device provided with a casing, a plurality of light sources, a deflection scanning unit that deflects and scans light beams from the plurality of light sources onto a plurality of bodies to be scanned, and a plurality of optical units arranged between the deflection scanning unit and the bodies to be scanned, in which optical unit supporting members that support the optical units are provided, the optical unit supporting members support the plurality of optical units arranged at predetermined intervals, and a thermal expansion coefficient of the optical unit supporting members is lower than a thermal expansion coefficient of the casing.

Optical scanning device and image forming device provided with optical scanning device

An optical scanning unit irradiates a polygon mirror with a plurality of light beams emitted from a light source according to image data, and scans and exposes a plurality of photoreceptors with the plurality of light beams as scanning lights. The optical scanning unit comprises a primary optical system unit including an optical system that emits the plurality of light beams, which are emitted from the light source toward the polygon mirror, and a secondary optical system unit including an optical system that emits the light beams, which are reflected by the polygon mirror toward the photoreceptors. The arrangement is such that the primary optical system unit is fitted removably to the secondary optical system unit, and that a combined unit of the primary optical system unit and the secondary optical system unit is removably fitted to an image forming apparatus having the photoreceptors.

Optical scanning unit and image forming apparatus

A laser scanning optical system converts a plurality of beams emitted from the laser diode (LD) into parallel light using a collimator lens, shapes the parallel light using an aperture, and executes exposure of a plurality of lines simultaneously on a photoreceptor drum. To cause a necessary emitting point interval d determined uniquely from the magnification of the optical system to coincide with an emitting point interval of the LD used, the LD is rotated by an angle &#x3b8; against the main optical axis plane thereof. In this case, a converting device that converts the aspect ratio of a profile of the light beam emitted from the LD is provided. A conversion characteristic of the converting device is adjusted such that the characteristic is matched with a condition within a predetermined region following a characteristic of the optical system.

Laser scanning optical system and image forming apparatus

A line sensor that detects the edge position of a recording paper is provided on the upstream side of a transfer point where an image formed on a first photosensitive drum is transferred to the recording paper. When performing borderless image formation, the size of the image on the first photosensitive drum to be transferred to the midstream of the recording paper after detection of its edge position is changed to a smaller size based on the detection results by the line sensor, and subsequent image formation to the recording paper continues to be performed according to this image on the photosensitive drum whose size has been changed.

Image forming apparatus capable of suppressing developer waste

A color image apparatus which has a cooling arrangement to help prevent a plurality of light-scanning units for respective colors therein from being adversely influenced by heat from a thermally fixing unit within the apparatus. In a space portion where all light-scanning units are housed, an air-exhausting fan is provided in the vicinity of the light-scanning unit nearest to the thermally fixing unit, and an air hole is formed at a position farthest from the thermally fixing unit. Additionally a temperature sensor is mounted on the light-scanning unit nearest to the thermally fixing unit. Rotation speed of the air-exhausting fan is controlled so that the temperature detected by the sensor does not exceed a predetermined temperature limit.

Color image forming apparatus with a cooling structure for cooling components therein

An object of the invention is to provide an image forming apparatus in which a unit can be attached to the apparatus body in a status where a correct positional correlation between a photoconductive drum and each of other process devices mounted on a unit is maintained. A photoconductive drum is positioned within a copier body by a rotating drive shaft, and the other process devices mounted on a process unit are positioned within a copier body by a boss and a locking member. The boss positions the rotating drive shaft within the copier body. Since the locking member is fitted onto a front-side end of the rotation drive shaft, the locking member is positioned within the copier body by the rotating drive shaft. The other process devices mounted on the process unit are positioned within the copier body by the rotating drive shaft via the boss and the locking member. Accordingly, the photoconductive drum and each of the other process devices, which should maintain a predetermined positional correlation with each other within the copier body, are both positioned within the copier body by the rotating drive shaft.

Image forming apparatus

An image forming apparatus of the present invention includes a photoreceptor drum on which a toner image is formed, a transfer drum for transferring the toner image formed to transfer paper by bringing the transfer paper into contact with the photoreceptor drum, and a pair of register rollers for supplying the transfer paper to the transfer drum at a predetermined time and for curling the transfer paper in an arc. The register rollers include first and second rollers pressed against each other, the first roller being a predetermined hardness and the second roller being a hardness larger than the first roller. The transfer drum is disposed on the same side as the second roller with respect to an imaginary tangent line touching the surface of the second roller at one end of a contact section between the first and second rollers. The image forming apparatus also includes transporting means for supplying the transfer paper to the register rollers so that a front edge of the transfer paper comes into contact with the second roller, temporarily stops, and then continues to the transfer drum. The image forming apparatus also includes a means for changing the pressure that the register rollers are pressed together. Paper type, quality, thickness, and size are detected and the pressure is adjusted accordingly. The means for changing pressure includes a resilient member for the pressing the second roller against the first, and a changing member for changing the amount of deformation of the resilient member.

Image forming apparatus equipped with register rollers for curling

An image forming apparatus of the present invention includes a photoreceptor drum on which a toner image is formed, a transfer drum for transferring the toner image to paper by bringing the paper into contact with the photoreceptor drum, the transfer drum having a dielectric layer, a semi-conductive layer and a conductive layer laminated in this order from the paper side, a power source which is connected to the conductive layer so as to apply a predetermined voltage to the conductive layer, and a conductive roller for pressing the paper against a surface of the dielectric layer so as to produce a potential difference between the conductive layer and the paper. The potential difference induces charges of the same polarity as the voltage applied to the conductive layer on the surface of the dielectric layer, and charges of the opposite polarity on a back surface of the paper pressed against the surface of the dielectric layer. Thus, the paper electrostatically adheres to the transfer drum in a satisfactory manner. Moreover, unlike charging by atmospheric discharge, since the surface potential of the transfer drum is stable, it is possible to prevent unsatisfactory transfers and improve the image quality.

Transfer device for an image forming apparatus

Growing community of inventors

Yamatokoriyama, Japan

Takayuki Ohno