Hitachi Koki Co., Ltd.

Hitachi, Ltd.

Hitachi Koki

Yasuyuki Tsuji

Shuuho Yokokawa

Hiroshi Ueno

Kunitomo Takahashi

Youji Hirose

Isao Nakajima

Susumu Saito

Junichi Matsuno

Tsukasa Onose

Koji Doi

Muneyoshi Akai

Youichi Takeuchi

Yoshio Ogura

Akira Arimoto

Keiji Kataoka

Takeshi Mochizuki

Masataka Kawauchi

Yukio Otome

Isao Watanabe

Tsuyoshi Ogasawara

Akira Terakado

Kazutoshi Obara

Yoshihiko Sano

Takeshi Terakado

Satoshi Aita

Masaru Kawamoto

Koutaro Yamada

Teruaki Mitsuya

Masayasu Anzai

Sho Sawahata

Shuho Yokokawa

Yasuo Takuma

Yasushi Hashimoto

Kazuhiro Akatsu

Shigeru Obata

Yasuo Kikuchi

Tsuneki Kobayashi

Minoru Seino

Tomio Sugaya

Osamu Namikawa

Hidefumi Ohtsuka

Katsuhiko Suzuki

Hidenori Iwanaga

Kazuyuki Kubo

Katsuhiro Akinaga

Minoru Ohshima

Shigeo Nemoto

Tsukasa Ogawa

Yoshihiro Gunji

Takao Chikuzenya

Osamu Nishino

Yoji Hirose

Kimio Nakamura

Hiroshi Hakuta

Motoji Kurobane

Kouji Doi

Rikio Ohtani

Masaaki Akutsu

Katsuhiro Shinohara

Akira Takizawa

Masami Yamaki

Kazuo Takano

Syou Sawahata

Takehiro Honda

Koutara Yamada

Katsuhito Komoda

An exposure device of an electrophotographic apparatus which includes a rotary polyhedral mirror for scanning a plurality of laser beams on a photosensitive body, a beam interval adjusting member for adjusting an interval between the laser beams, a rotating mechanism for rotating the beam interval adjusting member, and an optical path position deciding device disposed on the side of the rotary polyhedral mirror in a laser beam advancing direction at the time of adjustment of the laser beam interval, the beam interval adjusting member being rotated so that the optical paths of the laser beams are decided by the optical path position deciding device. The optical path position deciding device may include a plate-like member with boresights or a CCD sensor and a CRT display.

Exposure device of electrophotographic apparatus with optical path

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 includes a feed roller mechanism disposed downstream of a transfer corotron 412 constituting a transfer section and composed of driven rollers 506 located on both edges of a continuous recording medium 100 which are outside an image transfer area and a drive roller 508 extending over the whole width of the continuous recording medium 100, so that when transferring a toner image from an image recording member 402, on which the toner image is to be formed, to the continuous recording medium 100, friction by the rollers achieves reliable conveyance against an attraction between the image recording member 402 and the continuous recording medium 100 without disturbing an unfixed image on the continuous recording medium 100. The image forming apparatus further includes a line sensor 43 for detecting a position where a reference edge of the recording medium is present, a line sensor output device which judges a position of the recording medium reference edge in cooperation with the line sensor to send a recording medium reference edge position signal or mask 61 adjustable in position for shielding a portion of a detection window of the line sensor, a recording medium position correction device 11 which finds a recording medium position correction value from an output of the line sensor for carrying out feedback control, and a guide 38 for preventing rising of the recording medium.

Continuous recording medium friction-conveying mechanism in image

An electrophotographic apparatus system or an electrophotographic apparatus provided according to the present invention has the discrepancy of printing speed between tandem and single printing removed. The electrophotographic apparatus system or the electrophotographic apparatus is provided with printing speed changeover means 23a, 23b, 24 not only to select a printing speed applicable for the case where printing is effected with a plurality of electrophotographic apparatus A, B operatively linked together and another printing speed serviceable for the case where printing is implemented with each of plural electrophotographic apparatus put into separate run independently of one another, but also to shift the printing speeds from one to another, whereby the electrophotographic apparatus system or the electrophotographic apparatus may provide normal performance in each of the respective formations of printing.

Electrophotographic printing system including a plurality of

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

A developing device in an electrophotographic apparatus, wherein a pole c.sub.1 which is a delivering magnetic pole of the second developing roll for delivering the developer to the first developing roll and a pole d.sub.1 which is a receiving magnetic pole of the second developing roll for receiving the developer from the first developing roll are set so as to be the same in polarity, whereas a pole a.sub.2 which is a receiving magnetic pole of the first developing roll for receiving the developer from the second developing roll and a pole g.sub.2 which is a delivering magnetic pole of the first developing roll for delivering the developer to the second developing roll are set to be equal in polarity, wherein each of an angle between the poles c.sub.1 and d.sub.1 and an angle between the poles a.sub.2 and g.sub.2 is set so as to be in a range of from 70.degree. to 120.degree., and wherein the magnetic flux density of each of a reaction pole induced between the poles c.sub.1 and d.sub.1 and a reaction pole induced between the poles a.sub.2 and g.sub.2 is set so as to be less than or equal to 0.015 tesla.

Developing device in electrophotographic apparatus including developing

Regulating parts E, F, of a developing agent regulating member 6, are arranged opposite to a photosensitive drum 7 with respect to a line connecting the centers of a developing roll 5 having a sleeve rotating in the direction of a and a developing roll 8 having a sleeve rotating in the direction of b. Holding members 10 which are slidable on the side plate of a developing apparatus are respectively provided at both ends of the developing agent regulating member. Developing agent is supplied from developing roll 5 to developing roll 8 through a back surface of the developing agent regulating member 6.

Developing apparatus having developer regulating member

A development process and a fixing process are carried out on a front side of a recording paper. The paper recorded on the first side is transported toward a returning transportation device. The development process and the fixing process are then carried out on a back side of the paper. A nozzle for blowing out an air flow, an inverter roll for inverting the paper and the returning transportation device are arranged between the fixing station and a reversal station. The paper is deformed by the local cooling due to the air for peeling by the nozzle, the inverter roll and the returning transportation device. The portions (working regions) which receive the local cooling are arranged such that at most two of the working regions occur at any point of the recording medium paper. The inferiority of the local images in the defects in transfer and the local lowering degree in the density of the images are decreased.

Recording apparatus for printing both faces of a recording medium using

A developing device for use in an electrophotographic apparatus includes a casing for storing a developer including a toner and a carrier therein; a photosensitive drum having a surface on which an electrostatic latent image is formed; a carrying magnetic roll for drawing up the developer stored in said casing; a developing magnetic roll for forming a magnetic brush out of the developer fed by the carrying magnetic roll to develop the electrostatic latent image; and a developer mixing chamber including an impeller interposed between the carrying and developing magnetic rolls, for mixing the toner and carrier contained in the developer with each other, which is drawn up by the carrying magnetic roll, to supply the mixed developer to the developing magnetic roll.

Developing device having a developer mixing chamber for use in

In a multi-stage roll magnetic brush type of developing device, at least two opposite direction rotation rolls which rotate in an opposite rotation direction to that of a photosensitive body are arranged adjacently and oppositely to a photosensitive body, and at least one same direction rotation developing roll which rotates in the same rotation direction as that of the photosensitive body is arranged adjacently, oppositely to the photosensitive body and upstream of the opposite direction rotation developing rolls in the rotation direction of the photosensitive body. Thus, the path of carrying the developer by the same direction rotation developing roll and the opposite direction rotation developing rolls can be optimized. In the wide area printing at high speed, an image with stabilized printing quality can be obtained without an increase in the production cost.

Developing device for electrophotograph-type printer

A method of optically recording original information supplied from information generating device on an optical recording material in an optical recording apparatus, comprising the steps of: generating, from the original information, interpolating information which is to be interpolated in a sub-scanning direction of the optical recording material; and optically recording the interpolating information in the sub-scanning direction by a plurality of laser beams.

Optical recording apparatus and method for adding information in a

A toner density detection method for an electrophotographic apparatus in which driving of a rotary roll provided at an outlet of a special vessel is continued for a predetermined period of time (e.g., several seconds) after the operation of the electrophotographic apparatus is stopped. All or substantially all of the developing agent is thus exhausted or removed from the special vessel after the electrophotographic apparatus is stopped, so that the true permeability of the developing agent can be detected by a permeability sensor when the operation of the electrophotographic apparatus is restarted. As a result, the toner density of the developing agent can be controlled and kept normal, so that the printing quality can be stabilized.

Toner density detection method for electrophotographic apparatus

An apparatus for printing on opposite surfaces of a strip of printing paper using two electrophotographic printing units wherein each printing operation is of high quality and thermal damage to the printing is minimized. The apparatus includes a first electrophotographic printing unit for printing on the front surface of the printing paper, a buffer unit for temporarily holding the printing paper discharged outside of the first electrophotographic printing unit, a turn unit for turning over the printing paper, and a second electrophotographic printing unit for printing the reverse surface of the printing paper. A toner having a low melting temperature is employed for each of the first and second electrophotographic printing units so that developing treatment is conducted only with the aid of a heat roll but without any use of a preheating plate. A back-up roll adapted to cooperate with the heat roll is coated with a tetrafluoroethylene-based synthetic resin. The second electrophotographic printing unit is provided with a paper presser for squeezing the printing paper against a photosensitive drum only within the printing width range. A retract mechanism is operatively connected to the paper presser.

Apparatus for printing on opposite surfaces of a strip of printing paper

To adjust the posture of a sheet being conveyed, movable checker members provided adjacent to the conveyance path for the sheet are once driven in the direction of conveyance of the sheet before the members touch the sheet and are subsequently decelerated, the members being caused to abut against the front end of the sheet during the deceleration, thereby checking the sheet and thus correcting any skew thereof. Further, for positioning the sides of the sheet, the sheet is taken out of a hopper by way of a separating device and is guided and fed in such a manner that its front corner will not be caused to abut against a side registration guide, and subsequently the sheet is conveyed toward the guide by way of obliquely extending conveyer belt devices and one side of the sheet is brought into contact with the guide for positioning after a front corner of the sheet has passed at least the edge of the guide.

Method and apparatus for adjusting posture of sheets

A method of controlling print positioning comprises the steps of: detecting the time which elapses until a sheet of paper reaches a given position; predicting the time which would elapse until the paper reaches an image transfer position on the basis of the time detected in the detection step; calculating the time difference between the predicted time and an elapse time calculated on the basis of a paper carrying speed pattern which is previously stored and has at least two speeds; and controlling the paper carrying speed so that the calculated time difference becomes zero, thereby preventing any misregistration between a toner image and the paper.

Sheet registration method and apparatus for calculation of delay time

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Ibaraki, Japan

Yasuyuki Tsuji