Hitachi Koki Co., Ltd.

Ricoh Company, Ltd.

Hitachi Printing Solutions, Ltd.

Ricoh Printing Solutions, Ltd.

Yoshihiko Sano

Nobuyuki Furuya

Yasuyuki Tsuji

Kazutoshi Obara

Takeshi Terakado

Masaru Kawamoto

Susumu Saito

Shinya Kobayashi

Takeshi Uchida

Sadanori Kobashi

Teruaki Mitsuya

Nobuyoshi Hoshi

Shinichi Akatsu

Shunichi Oohara

Hisao Okada

Satoshi Ueda

Takayuki Muneyasu

Satoru Tao

Yoshinori Kawaai

Kiyomi Tsuchiya

Yoshimichi Ikeda

A belt-conveyor device includes a detecting unit that detects a belt position in a width direction of the endless belt for a plurality of times within more than a cycle of the endless belt, the width direction being a direction orthogonal to direction of travel of the endless belt; an average calculating unit that calculates an average belt position from the belt positions detected by the detecting unit; a storing unit that stores therein a plural sets of correction values and belt positions; and a meander correcting unit that corrects meander of the endless belt based on a correction value that corresponds with the average belt position in the storing unit.

Belt-conveyor device and image forming apparatus

A belt conveyor includes: an endless belt that is looped over a plurality of rollers, the plurality of rollers including a drive roller and a meandering correction roller; a drive unit that rotates the drive roller to drive the endless belt; a meandering correction unit that adjusts an inclination of the meandering correction roller to correct meandering of the endless belt in a width direction thereof; a plurality of position detection units that detect positions of the endless belt in the width direction thereof and output detection signals; and a meandering correction control unit that selectively uses the detection signals from the plurality of detection units to control the meandering correction unit.

Belt conveyor and image forming apparatus to detect and correct meandering of a belt

An electrophotographic apparatus is equipped with one or more printing sections including a photoreceptor, a charger that electrically charges the surface of the photoreceptor, an optical scanning section that optically scans the surface of the charged photoreceptor with a laser beam, a developer that develops image areas formed by optical scanning, a toner hopper that supplies toner to the developer, and an image transfer unit that transfers the developed image to a recording member. In this apparatus, the developer and toner hopper can be mounted and demounted separately and a plurality of toner hoppers and developers are changeable according to the kinds of toner colors to be used. Thus, of the developers and toner hoppers is equipped with a device that outputs electric signals to detect the correspondences of the toner hoppers and the developers.

Electrophotographic apparatus

In a printing apparatus in which a sheet handling device for conducting plural kinds of post processing is connected to a subsequent stage of an image forming device, a plurality of sheet feeding apparatuses disposed in the sheet handling device have a sheet residual amount detecting sensor and a sheet exhaustion detecting sensor. When the sheet residual amount detecting sensor detects that the number of sheets in an inserter is smaller than a predetermined number, the image forming device transports a sheet after it is confirmed by the sheet exhaustion detecting sensor that a sheet remains in the inserter.

Printing apparatus

In an electrophotographic apparatus, regions having at least three different potential levels Vc, Vw, and Vr are formed on a photosensitive member by using an exposing device, and developing processes respectively using colored particles of different kinds are performed by normal development and reversal development on two potential levels Vc and Vr excluding the intermediate potential level Vw. The apparatus has an auxiliary exposing unit for forming a fringe development preventing potential in an edge of an image forming region in order to prevent fringe development from occurring. The auxiliary exposing unit sets an auxiliary exposure amount by performing pulse-width modulation on a laser driver.

Electrophotographic apparatus having a fringe development preventing mechanism

In an image forming unit system, a sheet handling unit having a fixed sheet carrying-in rate is connected to an image forming unit having a sheet ejection rate controlled variably so that stable sheet carrying can be achieved. The sheet carrying rate (VF) of a sheet carrying-in roller pair (26) provided in a sheet handling unit (2) is defined to be higher than the sheet carrying rate (VU and VD) of a sheet ejection roller pair (16) provided in an image forming unit (1). The pressing force (F2) between the rollers of the sheet carrying-in roller pair is defined to be smaller than the pressing force (F1) between the rollers of the sheet ejection roller pair.

Image forming unit system

A printed paper sheet, on which plural pages of image are formed, is cut by detecting the position of conveying, the dimension of paper width and the amount of skew of the printed paper sheet, and by controlling the position of a slitter for cutting the printed paper sheet based on the detected result. The plural sheets of the cut printed paper sheets are divided so as to pass through plural routes to pile them in order of page.

Printing apparatus with movable slitter for printed paper sheet

An image forming apparatus for forming images of plurality of pages on one cut sheet, includes: a sheet cutting mechanism for cutting a cut sheet on which images of a plurality of pages have been formed into smaller sheets the number of which corresponds to the number of the pages; a sheet arranging mechanism for arranging the smaller sheets thus provided; and a sheet stacking mechanism for stacking the smaller sheets thus arranged. Hence, it is unnecessary for the apparatus to have a sheet post-processing apparatus.

Image forming apparatus and sheet arranging method for the apparatus

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Ibaraki, Japan

Yoshihiko Sano