Hitachi, Ltd.

Michio Sumiyoshi

Akira Sasaki

Isamu Terashima

Hiroyuki Tadokoro

Akira Shimizu

Takeshi Kato

Junichi Matsuno

Masaru Nakano

Nobuaki Fukasawa

Satoshi Narita

Yoshio Ohuchi

Kiminori Takada

In order to provide a color electrophotography apparatus satisfying a power-saving specification fully by turning off the power supply to various parts so as to reduce the watt consumption when the parts are unnecessary, such as in a power-saving mode, the duplexer, which is optional to the color electrophotography apparatus, has a unit to indicate to the control device of the color electrophotography apparatus whether or not the electric power is to be fed from an electric power supply in the color electrophotography apparatus.

Power-saving type electrophotography apparatus suitable for use with optional unit having exclusive power supply

A double-surface printing apparatus, which is small-sized and has a simple construction to make it impossible to take out a sheet, of which one surface has been subjected to printing, from outside. The apparatus includes a paper discharge tray, to which sheets having been subjected to printing are discharged; a sheet reversing mechanism including a reversal/temporary storage unit for guiding a sheet in a direction different from a discharge direction toward the paper discharge tray, once exposing the sheet outside of the apparatus, and rotating conveying rollers in an opposite direction to thereby reverse the sheet; and a protective cover, which covers the sheet conveyed to the reversal/temporary storage unit so that a sheet, of which one-surface has been subjected to printing, cannot be taken out from outside.

Double-surface printing apparatus

A unit exclusive use power source is provided for a duplexer printing unit which is coupled to a color printer main body of an electrophotography apparatus. The unit exclusive use power source has a circuit for presenting an &ldquo;on&rdquo; state and &ldquo;off&rdquo; state of a supply of electric power to respective constituting components in the duplexer printing unit in accordance with an indication of a controlling device. When the color laser printer main body is in an electric power saving mode and when an abrupt duplex printing after release of the electric power saving mode is unnecessary, the controlling device enables an &ldquo;off&rdquo; state of the unit exclusive power source. Since an operation of the coupled duplexer printing unit is unnecessary, such as in the electric power saving mode time, the power source of the duplexer printing unit is presented to the &ldquo;off&rdquo; state. Thereby, the electrophotography apparatus satisfies electric power regulation value therefor.

Electrophotography apparatus

An intermediate transcription drum is supported so as to be driven in contacting relationship with a photosensitive belt. The rotating speed of the photosensitive belt driving motor is controlled by a control unit such that one rotation cycle of the intermediate transcription drum becomes a given cycle. An adjustment of the speed control data for the photosensitive belt driving motor is performed in the interval between electrostatic latent image forming. Thereby, a speed difference between the photosensitive belt and the intermediate transcription drum does not occur, and a plurality of the toner images can be transferred and accurately superposed onto the outer surface of the intermediate transcription drum.

Color printer with transfer and superposition of different color toner

An outer peripheral length of an intermediate transfer drum of a color laser beam printer is constituted in which a number of a beam detection signal obtained by one rotation of the transfer drum is formed as an integral number of a face number of a polygon mirror. A passing-through detection means detects the passing-through of a specified position mark on a photosensitive body belt and is provided on the photosensitive body drum at predetermined position. An image data requirement signal generating means controls a generating timing of an image data requirement signal for forming a toner image by the passing-through detection signal. A scanning line at a raster direction based on the beam detection signal after the transfer drum has rotated at one rotation returns and overlapped on a scanning line position formed on the first beam detection signal as a standard. A plural toner images having a different color each are formed on the transfer drum without color offset.

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Hitachi, Japan

Michio Sumiyoshi