Patent ID: 11953840
Assignee: CANON KABUSHIKI KAISHA
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 0:
1. An image forming apparatus comprising:
a first photosensitive drum configured to be rotationally driven;
a first exposure head including a first plurality of light-emitting portions arranged in a direction along an axis of rotation of the first photosensitive drum, and configured to form an image corresponding to a first color on a surface of the first photosensitive drum by light emitted from the first plurality of light-emitting portions;
a second photosensitive drum configured to be rotationally driven;
a second exposure head including a second plurality of light-emitting portions arranged in a direction along an axis of rotation of the second photosensitive drum, and configured to form an image corresponding to a second color on a surface of the second photosensitive drum by light emitted from the second plurality of light-emitting portions;
a transfer unit configured to transfer a toner image corresponding to the first color and a toner image corresponding to the second color to a first surface of a sheet;
a fixing unit configured to fix to the first surface of the sheet the toner image corresponding to the first color and the toner image corresponding to the second color transferred to the first surface of the sheet by the transfer unit;
a conveyance unit configured to invert the first surface and a second surface of the sheet on which the images have been fixed to the first surface and convey the sheet to the transfer unit, the second surface being a surface on an opposite side of the first surface; and
at least one processor configured to:
generate a first synchronization signal at a period corresponding to a resolution of an image in a direction corresponding to a direction of rotation of the first photosensitive drum, and generate a second synchronization signal at a period corresponding to a resolution of an image in a direction corresponding to a direction of rotation of the second photosensitive drum, a period at which the first synchronization signal is generated in a case where the first exposure head forms the image to be fixed to the second surface of the sheet being shorter than a period at which the first synchronization signal is generated in a case where the first exposure head forms the image to be fixed to the first surface of the sheet, and a period at which the second synchronization signal is generated in a case where the second exposure head forms the image to be fixed to the second surface of the sheet being shorter than a period at which the second synchronization signal is generated in a case where the second exposure head is to form the image to be fixed to the first surface of the sheet; and
cause the first exposure head to form one line of the image corresponding to the first color along the axis of rotation of the first photosensitive drum based on the first synchronization signal, and cause the second exposure head to form one line of the image corresponding to the second color along the axis of rotation of the second photosensitive drum based on the second synchronization signal, the second exposure head forming an image to be fixed to the first surface of the sheet on the surface of the second photosensitive drum at a timing at which the first exposure head starts forming an image to be fixed to the second surface of the sheet on the surface of the first photosensitive drum.