US 12,242,208 B2
Light-emitting chip including plurality of light-emitting portions, and image-forming apparatus
Daisuke Akagi, Tokyo (JP)
Assigned to CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Jul. 13, 2023, as Appl. No. 18/351,721.
Claims priority of application No. 2022-117429 (JP), filed on Jul. 22, 2022.
Prior Publication US 2024/0027932 A1, Jan. 25, 2024
Int. Cl. G03G 15/00 (2006.01); G03G 15/04 (2006.01); G03G 15/043 (2006.01); G06K 15/00 (2006.01); G06K 15/02 (2006.01); G06K 15/12 (2006.01)
CPC G03G 15/043 (2013.01) [G03G 15/04054 (2013.01); G06K 15/1228 (2013.01); G06K 15/1247 (2013.01); G06K 15/1261 (2013.01); G06K 15/1898 (2013.01); G03G 2215/0409 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A light-emitting chip mounted on a long circuit board, the light-emitting chip comprising:
a plurality of light-emitting portions arranged along a longitudinal direction of the circuit board, the plurality of light-emitting portions emitting light for exposing a photosensitive member;
a first electrical pad configured to receive image data for controlling the plurality of light-emitting portions on and off;
a second electrical pad configured to receive the image data; and
a drive circuit including:
a plurality of image-data transferring units provided so as to correspond one-to-one with the plurality of light-emitting portions and each outputting, based on the image data, a drive signal for controlling drive of a corresponding one of the plurality of light-emitting portions, the plurality of image-data transferring units including:
a first image-data transferring unit configured to output the drive signal to a first light-emitting portion;
a second image-data transferring unit configured to output the drive signal to a second light-emitting portion that is adjacent to the first light-emitting portion on one side in the longitudinal direction of the circuit board;
a third image-data transferring unit configured to output the drive signal to a third light-emitting portion that is adjacent to the second light-emitting portion on the one side in the longitudinal direction of the circuit board, and output, to one of the first and second image-data transferring units, a start signal that is an instruction to start outputting the drive signal; and
a fourth image-data transferring unit configured to output the drive signal to a fourth light-emitting portion that is adjacent to the third light-emitting portion on the one side in the longitudinal direction of the circuit board, and output, to one of the second and third image-data transferring units, a start signal that is an instruction to start outputting the drive signal;
a first signal line connected to the first and third image-data transferring units, the first signal line configured to transmit the image data received via the first electrical pad;
a second signal line configured to transmit the image data received via the second electrical pad;
a first switch circuit configured to switch between a first state in which the start signal output by the fourth image-data transferring unit is output to the second image-data transferring unit and the start signal output by the third image-data transferring unit is output to the first image-data transferring unit, and a second state in which the start signal output by the fourth image-data transferring unit is output to the third image-data transferring unit and the start signal output by the third image-data transferring unit is output to the second image-data transferring unit; and
a second switch circuit configured to switch between a third state in which the first and third image-data transferring units and the first signal line are connected, and the first and third image-data transferring units and the second signal line are not connected, and a fourth state in which the first and third image-data transferring units and the second signal line are connected, and the first and third image-data transferring units and the first signal line are not connected.