Method and apparatus for image forming capable of effectively adjusting image shifts
AssigneeRicoh Company, Ltd.
InventorsJoh Ebara, Toshiyuki Uchida
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Abstract
An image forming apparatus includes a plurality of image bearing members configured to bear respective images, an optical writing unit configured to write the respective images on the plurality of image bearing members by deflecting a laser beam on a polygon mirror, a transfer unit configured to transfer the respective images onto an image receiving member, and a controlling unit configured to perform an adjustment of a difference in phase of respective rotation speeds between the plurality of image bearing members at a timing of one of non-image forming operations during a series of image forming operations performed by the plurality of image bearing members, the optical writing unit, and the transfer unit.
Claims29
An image forming apparatus, comprising:
- a plurality of image bearing members configured to bear respective images;
- an optical writing unit configured to write the respective images on the plurality of image bearing members by deflecting a laser beam off a polygon mirror;
- a transfer unit configured to transfer the respective images onto an image receiving member;
- and
- a controlling unit configured to perform an adjustment of a difference in phase of respective rotation speeds between the plurality of image bearing members at a timing of one of non-image forming operations during a series of image forming operations performed by the plurality of image bearing members, the optical writing unit, and the transfer unit.
An image forming apparatus, comprising:
- bearing means for bearing images;
- writing means for writing the images on the bearing means by deflecting a laser beam off a polygon mirror;
- transferring means for transferring the images onto receiving means the images;
- and
- controlling means for controlling an adjustment of a difference in phase of respective rotation speeds between the bearing means at a timing of one of non-image forming operations during a series of image forming operations performed by the bearing means, the writing means, and the transferring means.
A method of adjusting an image shift, comprising the steps of:
- forming respective images on a plurality of image bearing members by deflecting a laser beam off a polygon mirror in an optical writing unit;
- transferring the respective images onto an image receiving member of a transferring unit;
- reading the respective images formed on the image receiving member;
- calculating an amount of shift in the respective images based on a result of the reading step;
- adjusting respective rotation speeds of the plurality of image bearing members so that an amount of an image shift smaller than an amount of a pitch in a sub-scanning direction of consecutive main scanning lines of the laser beam is reduced;
- detecting respective rotation positions of the plurality of image bearing members;
- calculating an amount of a difference in phase of respective rotation speeds between the plurality of image bearing members based on a result of the detecting step;
- adjusting the phase difference according to the calculation result;
- and
- controlling an adjustment of the phase difference at a timing of one of non-image forming operations during a series of image forming operations.
Dependencies are inferred from the claim text.