Hitachi, Ltd.

Tetsuro Akasaki

Masahiko Saito

Isamu Terashima

Junichi Matsuno

Masaru Nakano

Shoji Ukei

Tomio Hayano

Motoyuki Suzuki

Masahiro Kimura

Akira Sasaki

Kazuhiro Wakamatsu

Toru Miyasaka

Tadashi Okano

Hiroyuki Tadokoro

Masashi Yamamoto

Akira Shimada

Taisaku Seino

Mitsuo Suzuki

Seiichi Hayashi

Shogo Matsumoto

Masafumi Suzaki

Keiji Kamio

Shoji Takeya

Kazushige Oonishi

Yasushi Kinoshita

Shigetaka Furukawa

Akira Mori

Hidenobu Takahashi

Masahiro Nakano

Toshiya Sato

Koichi Niwa

Tomiyoshi Sato

Jin Sawahata

An image forming apparatus in which a distance along a photosensitive belt from a cleaning unit to an exposing position is set to be shorter than a distance from the rear end of a print image to the front end of the following print image, so that a latent image is not formed by an exposing unit when a joint of the photosensitive belt passes the cleaning unit.

Image forming apparatus with reduced latent image vibration caused by photosensitive belt joint

An ion flow recording apparatus performs recording making density modulation every pixel. When developing on a fine grain toner is to be performed using a liquid developer for an electrostatic latent image, a developing unit (developing roller) is disposed to face a direction of gravity. Namely, a control valve is provided on a pipe for application of a developer to the developing roller or on a joint portion between the pipe and a developer tank, developing units of different two colors are joined to their developer tank portions, and a rotary shaft is provided on the joint portion to be positioned at a point of symmetry to provide alternate use of the two developing units upon turning them. Therefore, developing for a plurality of colors can be simply performed, and such turning of the developing units enables prevention of the toner from deposition in the liquid developer during developing, thereby making it possible to perform a clear recording.

Ion flow recording apparatus and liquid developing method

Registration controlling methods are provided for a color electrophotographic apparatus capable of forming an image without color registration errors and uneven color. This is accomplished by preventing a photosensitive medium from being undesirably moved in the direction perpendicular to the transportation direction caused by an electrostatic attractive force between the photosensitive medium and an intermediate transfer device, even if there is a twist between the fixed axis of the member supporting the photosensitive medium and the axis of the member supporting the intermediate transfer device. With these methods, a fur brush cleaner made of a conductive brush is detached from the intermediate transfer device during the time period after the start of driving the photosensitive medium and until the front edge of the photosensitive medium reaches the intermediate transfer device. A small amount of toner therefore always exists between the intermediate transfer device and the photosensitive medium during the transportation of the photosensitive medium, thereby reducing the electrostatic attractive force between the intermediate transfer device and the photosensitive medium and preventing the photosensitive medium from being undesirably moved in the direction perpendicular to the transportation direction. Also during this time period, the photosensitive medium is irradiated by a fade lamp to reduce electric charges on the photosensitive medium.

Electrophotographic apparatus having an intermediate transfer device and

A developing apparatus includes toner powder in the form of fine colored powder, a toner carrier, and a frictional controlling member for contacting under a pressure with the toner carrier under pressure to frictionally charge the toner powder and form a thin toner layer on the toner carrier. The toner carrier on which the thin toner layer is formed is rotated so as to transport the thin toner layer to an opposing location on a toner image carrier on which an electrostatic latent image is formed to convert the electrostatic latent image into a visible image. The developing apparatus includes a toner supply roller disposed in rotating contact with the toner carrier at a side of the toner carrier, the frictional controlling member being provided at a position in contact with the toner carrier downstream of the toner supply roller; and a rotatable toner scraping member is provided in a neighboring relationship below the toner supply roller and the frictional controlling member.

Image forming apparatus having improved toner carrier arrangement

An intermediate transfer unit is constructed by covering a conductive cylindrical base member of drum-shape with an elastic member of belt-shape, the elastic member of belt-shape being adhesively fixed to the base member with an adhesive agent, grooves or pits being provided on the surface of the cylindrical base member, the elastic member of belt-shape being adhesively fixed by the adhesive agent filled in the grooves or pits. The adhesive agent has a resistivity smaller than at least the resistivity of the elastic member of belt-shape. By doing so, it is possible to construct and keep the uniform distribution of resistivity without change by environment and deterioration with age, and to realize proper transferring. Furthermore, since the diametrical change of the drum due to uneven application of the adhesive agent can be minimized, the effect on misalignment in color can be minimized.

Image transfer element in a color image forming apparatus

The present invention relates to a desk-top type color electro-photographic apparatus which is easy in use, small in size and light in weight, wherein maintenance such as changing its photosensitive member can be performed by a user and color adjustment is performed with high accuracy of less than 100 .mu.m. Developing units for four colors are placed in a rank, a single endless-belt-shaped photosensitive member being placed below them to form an approximately oval shape, the photosensitive member being touched with a transfer member on its major axis side to transfer each color of images. In addition to this, the photosensitive member is employed a cartridge type for easiness of user's maintenance and constructed such that highly accurate positioning between the body of apparatus and the cartridge can be performed. Effect of the eccentricity of pulleys is decreased by means of making the pulleys wrapped with the photosensitive member have the identical diameter and making the diameter of the transfer member integer times as large as that of the pulley.

Color electro-photographic apparatus with endless-belt-shaped

A first control mark pattern, extending continuously in the scan direction of dots written onto a photo sensitive drum in a printer and cut in pieces in the direction perpendicular to the scan direction, and composed of lines is formed at a predetermined position on the photosensitive drum. Similarly, a second control mark pattern composed of a pattern including components in the direction perpendicular to the scan direction is formed on a second predetermined position on the photosensitive drum. The print density is controlled so as to be a desired one in accordance with the first control mark pattern formed. The widths of lines printed in accordance with the second control mark pattern formed are controlled so as to be the same in both the scan direction and the direction perpendicular to the scan direction.

Data printer

A mechanism for moving a magnetic head of a type at least having a chassis, a motor mounted on the chassis, a lead screw driven by the motor either in a normal rotational direction or in a reverse rotational direction, guide shafts mounted on the chassis, and a carriage carrying a magnetic head thereon and slidably mounted on the guide shafts. A connecting cam body is provided to convert the rotational movements of the lead screw into a reciprocating movement of the carriage, and the carriage is forced to one direction by the connecting cam body.

Mechanism for moving a magnetic head

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Hitachinaka, Japan

Tetsuro Akasaki