Image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorYoshihisa Nomura
Life of this patent
Estimating the term…
Abstract
In an image forming apparatus, a CPU can perform in a normal mode and a low mode in which a photoconductive drum rotates at a rate m/n times the rotational rate in the normal mode, and lower than the rotational rate in the normal mode. In the low mode, the CPU causes a synchronizing signal generation portion to generate a line synchronizing signal at a cycle 1/m times the cycle of the line synchronizing signal generated in the normal mode, and causes a chip data conversion portion to transmit, to an exposure head, the same image data signal m times and transmit, to the exposure head, an image data signal that brings a light-emitting portion into no light emission n-m times, in synchronization with n number of line synchronizing signals.
Claims5
An image forming apparatus comprising:
- a photoconductive drum;
- an exposure head including a plurality of light-emitting portions arranged along in a rotational-axis direction of the photoconductive drum, the plurality of light-emitting portions each being configured to emit light, based on an image data signal, for exposure of the photoconductive drum;
- a control signal generation portion configured to generate, at a predetermined cycle, a control signal that controls a timing of light emission of each of the plurality of light-emitting portions;
- an image data signal transmission portion configured to transmit the image data signal to the exposure head, in synchronization with the control signal, for light emission of each of the plurality of light-emitting portions based on the image data signal;
- and
- a controller configured to control the control signal generation portion, the image data signal transmission portion, and a rotational rate of the photoconductive drum, wherein
- the controller is configured to perform in a first mode in which the photoconductive drum rotates at a first rotational rate and a second mode in which the photoconductive drum rotates at a second rotational rate m/n times the first rotational rate, and lower than the first rotational rate, and
- in the second mode, for exposure for forming an image for one line onto a sheet, the controller causes the control signal generation portion to generate the control signal at a cycle 1/m times a cycle of the control signal generated in the first mode, and causes the image data signal transmission portion to transmit, to the exposure head, the same image data signal m times and transmit, to the exposure head, the image data signal that brings the plurality of light-emitting portions into no light emission n-m times, in synchronization with n number of the control signals.
Dependencies are inferred from the claim text.