Sharp Kabushiki Kaisha Corporation

Sharp Kabuhsiki Kaisha

Fumio Satoh

Yasuhiro Takai

Yoichi Shimazawa

Kenichi Morimoto

Kazuo Takahashi

Takashi Sugitou

Katsumi Nakanishi

An image forming apparatus includes a voltage generating section for generating one of an AC voltage and a voltage obtained by superposing an AC voltage on a DC voltage; an image carrier; and a contact charger for receiving the voltage generated by the voltage generating section and giving a surface potential corresponding to the received voltage to the image carrier by contact. Further, it includes a latent image forming section for forming a latent image by scanning the image carrier with a predetermined scanning period, and a control section for controlling the voltage generating section and the latent image forming section. The control section controls the voltage generating section and the latent image forming section so that a period of an AC component of the voltage generated by the voltage generating section is N times or 1/N times as long as the scanning period, where N is a natural number.

Image forming apparatus and method for removing fringe patterns

A fixing means for an electrophotographic copier includes a first roller and a second roller which are compressed against each other and serve to fix toner images on an image transferring medium passed therebetween. A control means is programmed to operate the rollers such that the heating of the second roller is continued for a predetermined length of time or until the surface temperature of the second roller reaches a certain predetermined temperature level after the surface temperature of the first roller reaches another predetermined temperature level such that the second roller is prevented from cooling down suddenly after the fixing operation is started. In another aspect of the present invention, the size of the image transferring medium passed between the rollers is detected and the heaters for the rollers are controlled accordingly such that temperature variations on the roller surfaces can be reduced and hence the roller lifetimes can be improved.

Fixing means for electrophotographic copier

Disclosed is a copying machine provided with a device for detecting a jammed original in the original-conveying path and a device that first discharges copying papers during image-transference process from the copying mechanism upon detection of paper jamming and then causes the value of the copied-paper counter to return to the value displayed before the jamming.

Copying machine with automatic original feeding device

Growing community of inventors

Habikino, Japan

Fumio Satoh