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US 2010/0247121 A1Published application
Image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorTakeshi Shimba
Life of this patent
Estimating the term…
Abstract
An image forming apparatus is configured to control the timing to switch a development unit by a development rotary after forming an image, based on the size of the image to be formed. Accordingly, if the switching of the development unit is completed within a time period corresponding to a trailing edge margin of an image area, a subsequent color image can be formed without idling an intermediate transfer member, so that the image forming apparatus can suppress or reduce degradation of the throughput.
Claims8
An image forming apparatus comprising:
- an image bearing member;
- a plurality of development units configured to form an image on the image bearing member;
- a development rotary configured to serially switch each of the plurality of development units to an image forming position at which an image is formed on the image bearing member;
- an intermediate transfer member on which the image formed on the image bearing member is transferred;
- and
- a control unit configured to give an instruction to start forming of the image if a mark that is a reference of starting the forming of the image and is provided on the intermediate transfer member, is detected,
- wherein the control unit is configured to compare a first time period, which is a time from start of switching of the development unit to detection of the mark, with a second time period, which is a time taken for switching the development unit, and if the second time period is shorter than the first time period, configured to start switching to a subsequent development unit by moving the subsequent development unit to the image forming position after the image is completely formed by the development unit existing at the image forming position.
4 more elements
An image forming apparatus comprising:
- an image bearing member;
- a plurality of development units configured to form an image on the image bearing member;
- a development rotary configured to serially switch each of the plurality of development units to an image forming position at which an image is formed on the image bearing member;
- an intermediate transfer member on which the image formed on the image bearing member is transferred;
- and
- a mark that is provided on the intermediate transfer member and is a reference of starting forming of the image;
- a control unit configured to give an instruction to start forming of the image if the mark is detected,
- wherein the control unit is configured to execute control for starting moving of a subsequent development unit to the image forming position so that the moving of the subsequent development unit to the image forming position is completed before image forming on the image bearing member by the subsequent development unit is started when the mark on the intermediate transfer member is detected.
5 more elements
An image forming apparatus comprising:
- an image bearing member;
- a plurality of development units configured to form an image on the image bearing member;
- a development rotary configured to serially switch each of the plurality of development units to an image forming position at which an image is formed on the image bearing member;
- an intermediate transfer member on which the image formed on the image bearing member is transferred;
- and
- a control unit configured to give an instruction to start forming of the image if a mark that is a reference of starting forming of the image and is provided on the intermediate transfer member, is detected,
- wherein the control unit is configured, if a length of the formed image is shorter than a first threshold value, to execute control for starting switching of the subsequent development unit to the image forming position.
4 more elements
Dependencies are inferred from the claim text.