Patent ID: 11934131
Assignee: CANON KABUSHIKI KAISHA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An image forming apparatus comprising:
an image forming unit comprising:
a photosensitive member;
a charging unit configured to uniformly charge the photosensitive member;
an exposure unit configured to form an electrostatic latent image on the photosensitive member by scanning the charged photosensitive member with laser light; and
a developing device configured to develop the electrostatic latent image to form an image on the photosensitive member;

a reading unit configured to read a test image, which is formed by the image forming unit, for detecting an image density of the image; and
a controller configured to:
control the image forming unit to form the test image;
detect periodic fluctuation of the image density based on a detection result of the test image which is acquired by controlling the reading unit to read the test image;

correct an image forming condition to suppress the detected fluctuation;
generate, based on the periodic fluctuation of the image density, a first correction bias for correcting a charging bias for charging the photosensitive member by the charging unit;
generate, based on the periodic fluctuation of the image density, a second correction bias for correcting a development bias for development by the developing device;
generate, in a state where a total of an amplitude of the first correction bias and an amplitude of the second correction bias exceeds a predetermined threshold, a laser power correction signal for correcting an amount of the laser light from the exposure unit based on the periodic fluctuation of the image density; and
control the image forming unit to form an image with the image forming condition in which a driving signal of the exposure unit is corrected with the laser power correction signal.