US 11,720,037 B2
Image forming apparatus
Kazuaki Nogami, Saitama (JP); Akinori Mitsumata, Tokyo (JP); and Takeo Kawanami, Kanagawa (JP)
Assigned to Canon Kabushiki Kaisha, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Oct. 4, 2021, as Appl. No. 17/493,669.
Claims priority of application No. 2020-170748 (JP), filed on Oct. 8, 2020.
Prior Publication US 2022/0113651 A1, Apr. 14, 2022
Int. Cl. G03G 21/08 (2006.01); G03G 15/04 (2006.01)
CPC G03G 15/04036 (2013.01) [G03G 21/08 (2013.01); G03G 2221/1684 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An image forming apparatus comprising:
a photosensitive conductor configured to be rotated;
a charging roller configured to charge a surface of the photosensitive conductor;
an exposure unit configured to form an electrostatic latent image on the surface of the photosensitive conductor charged by the charging roller;
a developing roller configured to develop the electrostatic latent image formed by the exposure unit with toner to form a toner image;
a transfer roller configured to transfer the toner image formed on the surface of the photosensitive conductor by the developing roller to a transfer-receiving member;
an irradiation unit having a light source provided at a first end of the irradiation unit in a rotation axial direction of the photosensitive conductor and a light guide configured to guide a light emitted from the light source in the rotation axial direction, wherein the irradiation unit is configured to irradiate the surface of the photosensitive conductor with the light after the toner image is transferred to the transfer-receiving member by the transfer roller; and
a light shield configured to block the light irradiated from the irradiation unit in the rotation axial direction,
wherein the light shield is configured so that a quantity of blocking the light irradiated from the irradiation unit is different in the rotation axial direction,
wherein the light guide includes a first portion near the first end of the irradiation unit, a second portion away from the first end of the irradiation unit in the rotation axial direction of the photosensitive conductor, and a Fresnel portion dispersing the light for irradiating of the photosensitive conductor,
wherein the quantity of blocking the light irradiated from the irradiation unit by the light shield is greater at the first portion than at the second portion in the rotation axial direction, and
wherein a width in a direction perpendicular to a longitudinal direction of the light guide of the Fresnel portion at the second portion is wider than a width in the direction perpendicular to the longitudinal direction of the light guide of the Fresnel portion at the first portion.