US 12,117,743 B2
Exposure head and image forming apparatus
Shunsaku Kondo, Ibaraki (JP)
Assigned to Canon Kabushiki Kaisha, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Dec. 8, 2022, as Appl. No. 18/077,321.
Claims priority of application No. 2021-201844 (JP), filed on Dec. 13, 2021.
Prior Publication US 2023/0185212 A1, Jun. 15, 2023
Int. Cl. G03G 15/04 (2006.01); B41J 2/00 (2006.01); B41J 2/447 (2006.01); B41J 2/45 (2006.01); G06K 15/00 (2006.01); G06K 15/12 (2006.01)
CPC G03G 15/04054 (2013.01) [B41J 2/447 (2013.01); B41J 2/451 (2013.01); G03G 15/04063 (2013.01); G06K 15/1252 (2013.01); G06K 15/1261 (2013.01); G03G 15/04036 (2013.01); G03G 2215/0409 (2013.01); G03G 2215/0412 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An exposure head configured to form an electrostatic latent image by exposing a charged surface of an image bearing member that is movable in a first direction, the exposure head comprising:
a plurality of light emitting boards each including a plurality of light emitting elements disposed side by side in a second direction intersecting with the first direction, the plurality of light emitting boards being disposed along the second direction and alternately in the first direction, the plurality of light emitting boards being divided into a first light emitting board group and a second light emitting board group, the first light emitting board group being disposed on a first side in the first direction, the second light emitting board group being disposed on a second side in the first direction;
a first lens array configured to condense light emitted from the plurality of light emitting elements disposed on the first light emitting board group onto the surface of the image bearing member; and
a second lens array configured to condense light emitted from the plurality of light emitting elements disposed on the second light emitting board group onto the surface of the image bearing member,
wherein a distance in the first direction between the first light emitting board group and the second lens array is set such that a light amount entering the second lens array is equal to or less than 20% of a light amount emitted from the plurality of light emitting elements disposed on the first light emitting board group,
wherein a distance in the first direction between the second light emitting board group and the first lens array is set such that a light amount entering the first lens array is equal to or less than 20% of a light amount emitted from the plurality of light emitting elements disposed on the second light emitting board group, and
wherein the light emitting elements are organic electroluminescence elements.