US 11,988,976 B2
Image forming apparatus that scans photosensitive member using plurality of scan beams
Hiroyuki Fukuhara, Shizuoka (JP); Takashi Kawana, Tokyo (JP); and Chihiro Shirakawa, Shizuoka (JP)
Assigned to CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Feb. 21, 2023, as Appl. No. 18/112,070.
Claims priority of application No. 2022-025606 (JP), filed on Feb. 22, 2022.
Prior Publication US 2023/0266693 A1, Aug. 24, 2023
Int. Cl. G03G 15/043 (2006.01)
CPC G03G 15/043 (2013.01) 21 Claims
OG exemplary drawing
 
1. An image forming apparatus, comprising:
a photosensitive member;
a scan unit including at least a first light source and a second light source, the scan unit being configured to form an electrostatic latent image on the photosensitive member by emitting a first scan beam from the first light source and scanning a plurality of sections on the photosensitive member in a main scanning direction at an inconstant scan speed, and form an electrostatic latent image on the photosensitive member by emitting a second scan beam from the second light source and scanning the plurality of sections on the photosensitive member in the main scanning direction at an inconstant scan speed;
a detection unit configured to detect the first scan beam; and
a control unit,
wherein
the control unit:
performs first correction in which, in order to emit the first scan beam from the first light source, a light emission period of the first scan beam per pixel is changed in accordance with which section in the main scanning direction is scanned by the first scan beam,
performs second correction in which, in order to emit the first scan beam from the first light source, a light exposure amount by which the photosensitive member is exposed to light by the first scan beam is changed in accordance with which section in the main scanning direction is scanned by the first scan beam,
performs third correction in which, in order to emit the second scan beam from the second light source, a light emission period of the second scan beam per pixel is changed in accordance with which section in the main scanning direction is scanned by the second scan beam, and
performs fourth correction in which, in order to emit the second scan beam from the second light source, a light exposure amount by which the photosensitive member is exposed to light by the second scan beam is changed in accordance with which section in the main scanning direction is scanned by the second scan beam, and
based on a detection timing at which the detection unit has detected the first scan beam, the control unit controls scan start timings at which the first scan beam and the second scan beam start scanning of the photosensitive member.