Back to results
US 2012/0269528 A1Published application
Image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorsYoshikuni Ito, Yoshihiro Shigemura, Ichiro Okumura, Seiji Hara
Life of this patent
Estimating the term…
Abstract
A rotational speed of an image bearing member on a downstream side is controlled so as to reduce a detection time difference between a leading end section of first electrostatic latent image indexes of an image bearing member and a leading end section of second electrostatic latent image indexes of a transfer medium in an area of a leading end margin preceding an effective image area.
Claims10
An image forming apparatus comprising:
- a movable intermediate transfer member;
- a first image forming unit that includes a rotatable first image bearing member, and that forms a toner image to be transferred to the intermediate transfer member on the first image bearing member;
- a second image forming unit that is arranged on a downstream side of the first image forming unit in a moving direction of the intermediate transfer member, that includes a rotatable second image bearing member, and that forms a toner image to be transferred to the intermediate transfer member on the second image bearing member;
- a first index forming means that forms a plurality of first electrostatic latent image indexes at positions adjacent to a toner image to be formed on a recording material in a width direction of the first image bearing member, the first electrostatic latent image indexes formed along the toner image to be formed on the recording material from a position on an upstream side of a leading end of the toner image to be formed on the recording material in a rotation direction of the first image bearing member, and a section of the first electrostatic latent image indexes which is formed on the upstream side of the leading end of the toner image, and which is formed so as to have larger index intervals than a section adjacent to the toner image;
- a transfer unit that transfers the first electrostatic latent image indexes formed on the first image bearing member to the intermediate transfer member;
- a second index forming means that forms a plurality of second electrostatic latent image indexes at positions adjacent to a toner image to be formed on the recording material in a width direction of the second image bearing member, the second electrostatic latent image indexes formed along the toner image to be formed on the recording material from a position on an upstream side of a leading end of the toner image to be formed on the recording material in a rotation direction of the second image bearing member, and a section of the second electrostatic latent image indexes which is formed on the upstream side of the leading end of the toner image, and which is formed so as to have larger index intervals than a section adjacent to the toner image;
- a control unit that controls an operation of at least the second image forming unit so as to maintain a set positional relationship between the first electrostatic latent image indexes and the second electrostatic latent image indexes transferred to the intermediate transfer member;
- and
- an operation start control unit that starts controlling the operation of at least the second image forming unit so as to maintain the set positional relationship between the sections of the first and second electrostatic latent image indexes with the larger index intervals.
6 more elements
An image forming apparatus comprising:
- a movable intermediate transfer member;
- a first image forming unit that includes a rotatable first image bearing member, and that forms a toner image to be transferred to the intermediate transfer member on the first image bearing member;
- a second image forming unit that is arranged on a downstream side of the first image forming unit in a moving direction of the intermediate transfer member, that includes a rotatable second image bearing member, and that forms a toner image to be transferred to the intermediate transfer member on the second image bearing member;
- a first index forming means that forms a plurality of first electrostatic latent image indexes at positions adjacent to a toner image to be formed on a recording material in a width direction of the first image bearing member, the first electrostatic latent image indexes formed along the toner image to be formed on the recording material from a position on an upstream side of a leading end of the toner image to be formed on the recording material in a rotation direction of the first image bearing member, and a section of the first electrostatic latent image indexes which is formed on the upstream side of the leading end of the toner image, and which is formed so as to have larger index intervals than a section adjacent to the toner image;
- a transfer unit that transfers the first electrostatic latent image indexes formed on the first image bearing member to the intermediate transfer member;
- a second index forming means that forms a plurality of second electrostatic latent image indexes at positions adjacent to a toner image to be formed on the recording material in a width direction of the second image bearing member, the second electrostatic latent image indexes formed along the toner image to be formed on the recording material from a position on an upstream side of a leading end of the toner image to be formed on the recording material in a rotation direction of the second image bearing member, and a section of the second electrostatic latent image indexes which is formed on the upstream side of the leading end of the toner image, and which is formed so as to have larger index intervals than a section adjacent to the toner image;
- a first detection unit that comes in contact with a surface of the intermediate transfer member opposite a surface of the intermediate transfer member facing the second image bearing member, and that detects the second electrostatic latent image indexes;
- a second detection unit that comes in contact with the surface of the intermediate transfer member opposite the surface of the intermediate transfer member facing the second image bearing member, and that detects the first electrostatic latent image indexes transferred to the intermediate transfer member;
- and
- a control unit that controls an operation of at least the second image forming unit so as to maintain a set positional relationship between the first electrostatic latent image indexes transferred to the intermediate transfer member and the second electrostatic latent image indexes based on detection results by the first detection unit and the second detection unit.
7 more elements
Dependencies are inferred from the claim text.