US 12,085,869 B2
Light-emitting device and image forming apparatus
Daisuke Akagi, Tokyo (JP)
Assigned to Canon Kabushiki Kaisha, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on May 17, 2023, as Appl. No. 18/319,289.
Claims priority of application No. 2022-086486 (JP), filed on May 27, 2022; application No. 2022-117428 (JP), filed on Jul. 22, 2022; application No. 2022-132719 (JP), filed on Aug. 23, 2022; and application No. 2023-059526 (JP), filed on Mar. 31, 2023.
Prior Publication US 2023/0384706 A1, Nov. 30, 2023
Int. Cl. G03G 15/043 (2006.01); G03G 15/04 (2006.01); G06K 15/00 (2006.01); G06K 15/12 (2006.01)
CPC G03G 15/043 (2013.01) [G03G 15/04036 (2013.01); G06K 15/1228 (2013.01); G06K 15/408 (2013.01); G03G 2215/0412 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An image forming apparatus to form an image on a recording medium, the image forming apparatus comprising:
a photosensitive drum;
a light-emitting chip including a light-emitting portion configured to emit light for exposing a surface of the photosensitive drum based on supply of a driving current to the light-emitting portion according to an image signal, and including a driving portion configured to drive the light-emitting portion;
a substrate on which a plurality of light emitting chips are mounted; and
a controller configured to control the driving portion by transmitting a signal to the light-emitting chip and to output a digital signal corresponding to a target amount of light of the light-emitting portion to the light-emitting chip,
wherein the light-emitting chip further includes:
a voltage source configured to output a reference voltage,
a digital-to-analog (D/A) converter configured to convert the digital signal into a voltage corresponding to the digital signal based on the reference voltage output from the voltage source, and
a switch configured to switch, based on a control signal from the controller, a connection state between the voltage source and the D/A converter to a first state where the voltage source and the D/A converter are connected to each other and the voltage source supplies the reference voltage to the D/A converter, and a second state where an electrical connection between the voltage source and the D/A converter is disconnected.