US 10,241,445 B2Granted

Image forming apparatus

AssigneeCanon Kabushiki Kaisha

InventorsShunsuke Mizukoshi, Takaaki Shinkawa, Jun Miura, Takahiro Ikeda, Yuji Kawaguchi

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Abstract

An image forming apparatus operable in a mode of forming an image using only a part of image forming stations. In the mode, a developing device contacts an image bearing member in a part of the image forming stations, and the developing device is spaced from the image bearing member in the rest of the image forming stations. The contact pressure between the image bearing member and a transferring device is made smaller in the rest than in the part. The image forming operation in the mode is executed while the image bearing members of the part and the rest are rotated. A controller is configured such that when the operation in the mode is continuously executed for a time period longer than a predetermined period, the contact pressure in the rest is made larger than the above-mentioned smaller contact pressure.

Claims14

Dependent claims

An image forming apparatus comprising:

a plurality of image forming stations, each including a rotatable image bearing member and a developing device configured to develop an image on said image bearing member with a developer, wherein said image forming apparatus is operable in a first mode in which the image is formed by only a part of said image forming stations and no image is formed by the rest of said image forming stations, and wherein an image forming operation in the first mode is executed by rotating said image bearing members of the part and the rest of said image forming stations;
a transferring device configured to transfer the images formed on said image bearing members of said image forming stations, wherein in the first mode, the part of said image forming stations is in a contacting state in which said image bearing members contact said transferring device;
a contacting/spacing device provided for the rest of said image forming stations and configured to enable the rest of said image forming stations to be in the contacting state or a spacing state in which said image bearing members are spaced from said transferring device;
and
a controlling device configured to control said contacting/spacing device such that the rest of said image forming stations is changed into the contacting state after the image forming operation has been executed for a predetermined period in the spacing state.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/868,106Filed 11 Jan 2018 · division
Priority: JP 2015-05004712 Mar 2015
Published: US 2018/0136591 A117 May 2018
Granted: 26 Mar 2019
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

G03G 15/1605
Of a toner pattern, e.g. a powder pattern , e.g. magnetic transfer: using at least one intermediate support
G03G 15/0136
For transferring a pattern to a second base: transfer member separable from recording member or vice versa, mode switching
G03G 15/1675
At least one of the recording member or the transfer member being rotatable during the transfer: with means for controlling the bias applied in…
G03G
Electrography

Family

Application15/067,659Parent of this division · filed 11 Mar 2016
US 2018/0136591 A1Pre-grant publication · published 17 May 2018
US 9,897,942 B2Parent of this division
US 2016/0266523 A1Published application
US 10,241,445 B2This patent

From the US filing history. Foreign family members aren’t listed.