Hitachi Koki Co., Ltd.

Hitachi, Ltd.

Akira Terakado

Yasushi Hashimoto

Teruaki Mitsuya

Yasuyuki Tsuji

Koji Kato

Akira Arimoto

Shinya Kobayashi

Yasuro Hori

Makoto Nakura

Takao Kumasaka

Yasuo Kikuchi

Yuzuru Simazaki

Isamu Komatsu

Minoru Seino

Masato Miwa

Shigetaka Fujiwara

Takashi Nakamura

Jun Ogino

Tatsuya Shiraishi

Yoshihiro Gunji

Kazuo Sakaki

Tatsuo Matsuda

Michio Endou

Yasushi Kimiwada

In order to provide a miniature full-color recorder having an excellent color reproducibility and to provide a full-color recorder having a wider color reproduction range beyond the range of subtraction color mixing of three primary colors, first and second potential split developing processes are continuously arranged for one recording medium.

Full-color recorder using potential split developing process

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 sheet carrying apparatus (,) includes: a sheet receiving means (,) for receiving a sheet ejected from a sheet output device (,); a first carrying path (,) for guiding the sheet; a second carrying path (,) branched out of the first carrying path; a carrying path switching means (,) provided in a branching portion between the first and second carrying paths; a first receiving device attachment portion (,) for detachably holding a first receiving device (,) for receiving the sheet ejected from the first carrying path; and a second receiving device attachment portion (,) for detachably holding a second receiving device (,) for receiving the sheet ejected from the second carrying path.

Sheet carrying apparatus

An air flow path switching device for a printing apparatus includes a sheet hopper which holds a plurality of sheets, a sheet switchback device for inverting the sheets so that both sides of the sheets can be printed on, sheet pickup devices associated, respectively, with the sheet hopper and the sheet switchback device for picking up sheets, and a blower device for supplying pressurized suction and discharge air to the sheet pickup devices. An air flow resistance existing in the sheet switchback device, when the sheet pickup device associated with the sheet hopper is connected to the blower, and an air flow resistance existing in the sheet switchback device, when the sheet pickup device associated with the sheet hopper is disconnected from the blower, are substantially equivalent.

Air flow path switching device for printing apparatus

An electrophotographic charger of the type in which a plurality of corona wires extend in the axial direction adjacent to and separated from the surface of a photosensitive drum in order to charge the surface. A plate-like etching grid is interposed between the corona wires and the drum to ensure the charge is uniformly placed on the drum. The grid is divided into a number of individual removable grids so that the distance between each grid and the adjacent corona wire, and the distance between each grid and the drum surface is substantially uniform.

Charger for electrophotography having a grid assembly

In a heat roll consisting of a mandrel and a surface layer, this invention comprises a fixing apparatus and a recording apparatus, wherein a thickness of the surface layer is formed not exceeding the thickness determined by a square root of the product of a heat diffusion rate of the surface material and a nip time required for a form to pass a nip zone, and a thickness of the mandrel is formed not less than the thickness determined by a square root of the product of a heat diffusion rate of the mandrel material and a one rotational period of the mandrel. Since the surface layer and the mandrel are so specified for the thickness as mentioned, a quantity of heat flowing from the mandrel into the surface layer multiplies, and thus a high fixing strength is obtainable. The fixing apparatus and the recording apparatus are provided further with a cleaning device high in cleaning capacity.

Fixing apparatus and recording apparatus

An electrophotographic image transfer member of bias-roller transfer type is capable of pressing a recording medium into contact with a toner image. The image transfer member has a rotatable supporting member, an elastic member provided around the supporting member, and a conductive resin layer formed on the surface of the elastic member. An electrical path is formed to enable supply of a bias voltage to the conductive resin layer. An image transfer device has the image transfer member and a cleaner capable of removing toner from the image transfer member upon frictional contact therewith. An electrophotographic apparatus has an image transfer member for bringing the recording medium into pressure contact with the toner image and for applying the bias voltage, and a mechanism for bringing the image transfer member towards and away from the photosensitive member in response to a signal indicative of execution of one of several basic steps of the electrophotographic process.

Electrophotographic image transfer member, electrophotographic image

A feeder for a electrophotographic printer to feed photo-sensitive paper onto the drum of the printer. Sheets of photo-sensitive paper are adhered to release paper. The sheets are separated from the release paper by rolling the sheets adhered to the release paper over a positioning roll, where separation occurs, and rolling the photo-sensitive sheets onto the drum and the release paper onto a take-up roll. The sheets are clamped at their front end to the drum the drum is rotated and the sheets are clamped at their rear end to the drum. The take-up roll is rotated by the driving force of a stepping motor and the frequency of the driving force is controlled to coincide with the rotational speed of the drum.

Feeder of sheet-like photo-sensitive material

Cut paper electrophotographic printers with continuous paper feed mechanisms including a pickup roll, a photosensitive drum, a charging unit, an optical unit, a host controller, a developing unit, a transfer unit and fixing rolls. Further included are first and second branch passages for providing alternate feeding paths to continuously feed cut paper sheets to the photosensitive drum.

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Hitachinaka, Japan

Akira Terakado