US Patent No. 9,395,687

ELECTROPHOTOGRAPHIC APPARATUS AND PROCESS CARTRIDGE


Patent No. 9,395,687
Issue Date July 19, 2016
Title Electrophotographic Apparatus And Process Cartridge
Inventorship Hiroyuki Tomono, Numazu (JP)
Yota Ito, Mishima (JP)
Daisuke Miura, Tokyo (JP)
Takashi Anezaki, Hiratsuka (JP)
Harunobu Ogaki, Suntou-gun (JP)
Assignee Canon Kabushiki Kaisha, Tokyo (JP)

Claim of US Patent No. 9,395,687

1. An electrophotographic apparatus comprising:
a cylindrical electrophotographic photosensitive member for carrying a toner image;
a charging unit contacting the electrophotographic photosensitive member; and
a transfer unit for transferring the toner image carried on the electrophotographic photosensitive member onto a transfer
material,

wherein the electrophotographic photosensitive member includes a charge-generating layer and a surface layer on the charge-generating
layer and

the electrophotographic apparatus satisfies the following formulae (1) and (4):
L1 L1>L4>L2  (4)
where L1 represents a range (mm) from the center of an image-forming region of the electrophotographic photosensitive member to an
end of a charged region of the electrophotographic photosensitive member in a longitudinal direction of the electrophotographic
photosensitive member,

L2 represents a range (mm) from the center of the image-forming region to an end of a transfer region of the electrophotographic
photosensitive member in the longitudinal direction of the electrophotographic photosensitive member,

L3 represents a range (mm) from the center of the image-forming region to an end of a region where the surface layer is placed
in the longitudinal direction of the electrophotographic photosensitive member, and

L4 represents a range (mm) from the center of the image-forming region to an end of a region where the charge-generating layer
is placed in the longitudinal direction of the electrophotographic photosensitive member.