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US 9,310,706 B2Granted
Image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorsKeisuke Ishizumi, Shinsuke Kobayashi, Ken Nakagawa
Life of this patent
Estimating the term…
Abstract
Test patches are formed such that lengths of the test patches in a rotational direction of the intermediate transfer member are shorter than a length of the intermediate transfer member from a primary transfer portion located in the lowermost stream among the plurality of primary transfer portions to the secondary transfer portion.
Claims18
An image forming apparatus comprising:
- a plurality of image bearing members on which electrostatic latent images are formed;
- a plurality of developing units configured to develop each of the electrostatic latent images formed on the image bearing members as a toner image;
- an intermediate transfer member;
- a primary transfer unit configured to transfer, as primary transfer, the plurality of toner images developed by the developing units to the intermediate transfer member in a plurality of primary transfer portions;
- a secondary transfer unit configured to transfer, as secondary transfer, the plurality of toner images which have been transferred as the primary transfer to the intermediate transfer member to a recording material in a secondary transfer portion;
- a supply unit configured to supply a common transfer current, to be used for the primary transfer and the secondary transfer, to the primary transfer unit and the secondary transfer unit;
- a forming unit configured to form a first test patch and a second test patch formed consecutively thereafter and next to the first test patch with no other test patches formed therebetween, the first and second test patches for correcting color misregistration or color density;
- and
- a detecting unit configured to detect the first test patch and the second test patch formed on the intermediate transfer member,
- wherein a length of the intermediate transfer member in a rotational direction thereof from a rear end of the first test patch to a front end of the second test patch which is formed subsequently to the first test patch with no other test patches formed therebetween the rear end of the first test patch and the front end of the second test patch, is longer than a length of the intermediate transfer member from a primary transfer portion located in the lowermost stream among the plurality of primary transfer portions to the secondary transfer portion.
7 more elements
An image forming apparatus, comprising:
- a plurality of image bearing members on which electrostatic latent images are formed;
- a plurality of developing units configured to develop each of the electrostatic latent images formed on the image bearing members as a toner image;
- an intermediate transfer member;
- a primary transfer unit configured to transfer, as primary transfer, the plurality of toner images developed by the developing units to the intermediate transfer member in a plurality of primary transfer portions;
- a secondary transfer unit configured to transfer, as secondary transfer, the plurality of toner images which have been transferred as the primary transfer to the intermediate transfer member to a recording material in a secondary transfer portion;
- a supply unit configured to supply a common transfer current, to be used for the primary transfer and the secondary transfer, to the primary transfer unit and the secondary transfer unit used for the transfer;
- a forming unit configured to form a first test patch and a second test patch formed consecutively thereafter and next to the first test patch with no other test patches formed therebetween, the first and second test patches for correcting color misregistration or color density;
- and
- a detecting unit configured to detect the first test patch and the second test patch formed on the intermediate transfer member,
- wherein lengths of the first test patch and the second test patch in a rotational direction of the intermediate transfer member are shorter than a length of the intermediate transfer member from a primary transfer portion located in the lowermost stream among the plurality of primary transfer portions to the secondary transfer portion, and a length of the intermediate transfer member in the rotational direction thereof from a rear end of the first test patch to a front end of the second test patch which is formed subsequently to the first test patch with no other test patches formed therebetween the rear end of the first test patch and the front end of the second test patch, is longer than the length of the intermediate transfer member from the primary transfer portion located in the lowermost stream among the plurality of primary transfer portions to the secondary transfer portion.
7 more elements
Dependencies are inferred from the claim text.