Hitachi, Ltd.

Kazuyoshi Matsuo

Akira Sasaki

Nobuaki Fukasawa

Masahiko Saito

Isamu Terashima

Hiroyuki Tadokoro

Makoto Otaka

Shinichi Hosaka

Hideyuki Haragakiuchi

Masashi Okuhama

Katuyoshi Onose

In an electrophotographic device, a method is provided in which laser power is regulated at two predetermined points of gradation. More specifically, a first laser power regulating means which regulates the magnitude of a laser power output and a second laser power regulating means which regulates the slope of laser power gradation characteristic are provided. Thereby, stabilization of the laser power output value is realized at any stage of the gradation, and an electrophotographic device can be provided which reduces variability in image quality between electrophotographic devices.

Laser beam emission control for electrophotographic device

An electrophotographic image forming apparatus is capable of restriction or elimination of the occurrence of a density fluctuation, such as a lateral stripe, and thereby can enhance the image quality. The electrophotographic image forming apparatus includes a photosensitive body, exposure device for forming an electrostatic latent image on the photosensitive body, at least two developers for developing the electrostatic image in mutually distinct colors for respectively forming toner images of mutually distinct colors, a transfer device for transferring the toner images of mutually distinct colors on a printing medium in an overlapping manner, and a fixing device for fixing the toner images transferred onto the printing medium. When one of the developers is maintained inoperative, that developer is forcedly operated for a reset operation thereof.

Electrophotographic image forming apparatus

The disclosure is concerned with an electrophotographic apparatus comprising a toner image supporting member on which a toner image developed on an electrostatic latent image is formed, transferring means for transferring the toner image on said toner image supporting member to a recording medium, conveying means for bringing the recording medium into contact with the image supporting member, a fixing roller and a compression roller in contact with each other to fix the toner image on the recording medium, heating means disposed inside at least one of the fixing roller and the compression roller, wherein there are provided temperature detection means for detecting the surface temperature of the fixing roller and state detection means for detecting the state of the fixing apparatus before starting of the fixing apparatus.

Electrophotographic apparatus and electrophotographic method

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Hitachi, Japan

Kazuyoshi Matsuo