Canon Kabushiki Kaisha

Youhei Suzuki

Takashi Kuwata

Michio Uchida

Hideki Ohta

Keisuke Mitsuhashi

Takamichi Matsuo

Kenji Abe

Tomonori Shida

Shoichi Zensai

Takuro Mita

Toshiaki Sako

Tetsuya Yamamoto

Tomoaki Nakai

Takeshi Shinji

Kiyoharu Yoshioka

Hisayuki Tomura

Takao Nada

Hidetoshi Yamashita

Takuma Abe

An image forming apparatus includes a sheet feed unit which feeds a sheet to an image forming unit forming an image on the sheet, a re-transport roller which reverses the sheet with a toner image fixed on the sheet and re-transports the sheet to the image forming unit, and a control unit which controls a sheet feed operation of the sheet feed unit for feeding the sheet. As the temperature of the re-transport roller sensed by the temperature sensing unit is decreased, the control unit retards the timing at which the sheet feed unit starts the sheet feed operation when a duplex image formation in which the image is formed on both sides of the sheet is performed after a one-side image formation is completed.

Image forming apparatus

An image forming apparatus includes: a sheet feed unit that feeds a sheet to an image forming unit forming a toner image on the sheet; a fixing unit that fixes the toner image formed in the image forming unit to the sheet; and a control unit that controls the sheet feed unit, when starting duplex image formation for forming both sides of the sheet after an one-side image formation, the control unit retards a timing to cause the sheet feed unit to start the sheet feed operation as the number of sheet with an image formed on one side thereof in the one-side image formation is greater.

The speed at which transfer-material enters a transfer region is controlled to prevent a phenomenon in which a toner image on an intermediate transfer belt is scraped by the leading edge of the transfer-material when the toner image is transferred onto the transfer-material. While the conveying speed of the transfer-material in a transfer nip coincides with the speed of the intermediate transfer belt, the transfer-material is conveyed at a speed lower than the peripheral speed of the intermediate transfer belt when the leading edge of the transfer-material comes into contact with the intermediate transfer belt, and the conveying speed of the transfer-material is increased by the time when the transfer-material enters the transfer nip.

A compact image forming apparatus is provided in which stains on the back of a transfer material can be prevented. In particular, in a marginless print mode in which a toner image can be formed to the edge of a transfer material, a large amount of toner adheres to a transfer-material bearing member. The image forming apparatus includes a collecting member that can temporarily collect the toner adhering to the transfer-material bearing member. The toner that is temporarily collected by the collecting member is transferred to an intermediate transfer member and is cleaned by a cleaning unit.

The image forming apparatus has a discharge device, an air blow device and a detection device, wherein an amount of blown air by the air blow device when the height of the recording materials detected by the detection device is higher than a preset first detection position is smaller than an amount of blown air by the air blow device when the detected height of the recording materials is lower than the first detection position. Thereby, there is provided an image forming apparatus which is improved in the alignment of the recording materials on the stacking portion.

The image forming apparatus includes a fixing apparatus capable of restraining offset of a toner in multifarious types of sheets and in a variety of environments at low costs. The fixing apparatus has a rotary fixing member and a nip forming member which forms a fixing nip portion by coming into contact with the rotary member. A recording material bearing an unfixed toner image is conveyed while being pinched by the nip portion. The fixing apparatus fixes a toner image onto the recording material. The fixing apparatus further has a bias applying means which applies a bias to the nip forming member. The bias applying means, before the recording material reaches the nip portion, applies a first bias to the nip forming member so that a surface of a rotary member is charged with electricity, and applies a second bias to the nip forming member while the recording material is conveyed by the nip portion.

Image forming apparatus with power supply for charging nip forming member and rotary fixing member

The image forming apparatus, includes a conveyor belt for bearing a recording material, capable of suppressing an image blur caused by a separating discharge at the separation of the recording material from the conveyor belt. To fix record materials on a transportation belt, the recording material is charged by a adhering member to electrically adhere the recording material to the conveyor belt. When the recording material is separated from the conveyor belt, a separating discharge occurs between the recording material and the conveyor belt, as the recording material is charged. In order to reduce the faulty of the toner image on the recording material caused by the separating discharge, the voltage applied to the adhering member is controlled for example according to a current which the recording material receives at the transfer position to mutually cancel the charge received at the transfer position by the adhering member.

Growing community of inventors

Suntou-gun, Japan

Youhei Suzuki