Hitachi Koki Co., Ltd.

Hitachi, Ltd.

Ricoh Printing Systems, Ltd.

Masato Miwa

Takashi Suzuki

Takao Umeda

Yoshitaka Fujinuma

Teruaki Mitsuya

Masayasu Anzai

Hiroyuki Mabuchi

Yasuo Takuma

Hirobumi Ooyoshi

Keisuke Kubota

Junichi Matsuno

Tatsuo Igawa

Yasushi Hashimoto

Shigeru Obata

Yasuo Kikuchi

Kenichi Kugai

Takashi Nishimura

Ryuuichi Shimizu

Akira Terakado

Tsutomu Nakagawa

Masami Takeshita

Kazuo Uno

Katsuya Kawai

Yosuke Saito

Osamu Nishino

Hideki Ando

Takasi Suzuki

Eita Sakaba

Masafumi Shimizu

Takao Takuma

Tetuya Nagata

Yousuke Saito

Kenji Nakamura

A fixing device wherein supposing that the total load given to a heating roller and a pressure roller is W (kgf) and the area of the pressure contact portion of the heating roller with respect to the pressure roller (nip area) is S (cm), the nip pressure (=W/S) is 2.7 kgf/cmor more and the length of the pressure contact portion in the direction parallel to the direction of conveyance of a recording material is defined to be 14 mm or more.

Fixing device including heating roller and pressure roller

A cleaning device is disposed substantially vertical above a photosensitive drum for the purpose of constructing a compact electrophotographic printer. The cleaning device includes a housing that accommodates an auxiliary toner conveying part and a sheet-like resilient member. A cleaning brush is also disposed in the housing so that a gap of 1-3 mm is formed between the cleaning brush and the auxiliary toner conveying part and resilient member. During an image forming operation, toner accumulates between the cleaning blade and the cleaning brush and is conveyed upward through the gap between the cleaning brush and the auxiliary toner conveying part and resilient member. The toner drops onto the cleaning brush near the top thereof and is conveyed by the cleaning brush to a screw. The screw discharges the toner from the cleaning device.

Cleaning device for image forming apparatus

To ensure stable feed of transfer material when a paper back vacuuming feed mechanism is employed in the path from a transfer section to a fixing section in an image forming apparatus, the image forming apparatus is such that the transfer section is arranged on the upper surface of the intermediate transfer unit; a transfer material feed apparatus is provided for vacuum feeding transfer material from the transfer section to the fixing apparatus; a guide tilted by a predetermined angle downward of the transfer material feed surface is provided at the outlet of the fixing apparatus of the transfer material feed apparatus; the nip portion of a fixing roller pair of the fixing apparatus is positioned downward of the extension line of the guide; and the tangent with respect to the nip portion of the fixing roller is tilted by a predetermined angle downward of the transfer material feed surface.

Image forming apparatus

A cleaning device for a fixing unit includes a winding shaft for holding a cleaning web and a sensor for detecting a trailing end of a cleaning web. A notched portion is formed in a winding shaft at a position opposing a detecting position of said sensor.

Cleaning device for a fixing unit

In an image forming apparatus, a length of a transporting passage between an induction roller pair and a reversal roller pair and a length of a transporting passage between the reversal roller pair and a feed roller pair are respectively set smaller than the smallest length in the transporting direction of a sheet used in an image forming apparatus. A time till the rotation of the reversal roller pair is switched to the forward rotation after a rear end of the sheet having a length in the transporting passage of 8.5 inch after reversal has passed through the reversal roller pair can be set shorter than a time when a leading end of a succeeding sheet inducted into a pull-in passage reaches the reversal roller pair.

Image forming apparatus having a sheet reversing device

A transfer belt for use in an electrophotographic apparatus for transporting an image support onto which a toner image formed on a surface of a photoconductor containing a photoconductive layer is transferred, and the transfer belt includes a surface layer formed from a coating liquid containing: a solvent; at least one kind of inorganic or organic fine particles dispersible in the solvent; and at least one kind of organic compound dissolved in the solvent. Also disclosed is an electrophotographic apparatus using the transfer belt.

Transfer belt and electrophotographic apparatus

A bias cleaning system has an electrically conductive brush roller for collecting toner which has to adhered a transfer belt by scrubbing the toner off the transfer belt under a condition in which a direct current voltage of the opposite polarity to the charge of the toner is applied to the brush roller. A corona charger is also provided for decreasing the amount of charge on the toner on the transfer belt in a region of the belt up-stream of the electrically conductive brush roller in the moving direction of the transfer belt.

Bias cleaning system and electrostatic printing apparatus therewith and

An imaging apparatus such that residual toner on a transfer/conveyer mechanism such as a transfer belt and an intermediate transfer material is effectively removable. High-tension voltage opposite in magnetic polarity (plus) to the charged toner and a photosensitive drum is applied to a discharger 15 provided ahead of a drive member 12 for driving a transfer belt 6. The residual toner on the transfer belt 6 is removed by a brush 21, and the residual foreign substances come in contact with the photosensitive drum 1 and move onto the photosensitive drum 1 before a printing operation is started. The foreign substances are then removed by a photosensitive drum cleaner.

Imaging apparatus and method for cleaning transfer/conveyer means

A belt-type transfer device which includes an endless belt rotating in contact with a photosensitive drum, with the belt being electrically charged by a corona discharger in a region of contact between the belt and the drum. A plate is provided for shielding the belt from the corona discharging in a vicinity of an outlet of the contact area to reduce electrostatic traction forces between the drum and the sheet in a vicinity of the outlet. The corona discharger may be located near an inlet of the region of contact with respect to a center thereof or a dielectric or electrically conductive film may be provided on an inner surface of the corona discharger on the contact area outlet side to increase the electrical charge of the belt at the inlet and the central portion of the region of contact. A control system detects an electric resistance value of the sheet and changes the corona discharging intensity in accordance with a detected value to stabilize an electrical charge of the belt or, a control system may be provided for slightly lowering a moving speed of the sheet as compared with a rotational speed of the drum at an outlet of the region of contact. Surface roughness of the belt is 5 .mu.m or less and the sheet delivery guides are provided having a volume resistivity of 10.sup.11 .OMEGA.cm or less, which reduces electrical charge caused on the sheet due to frictional contact.

Belt type transfer device for electrophotographic apparatus

Image forming apparatus capable of preventing the winding on the image

Growing community of inventors

Ibaraki, Japan

Masato Miwa