US 7,321,740 B2
Developing cartridge and electrophotographic image forming apparatus employing the same
Sam-Seok Choi, Suwon-si (Korea, Republic of); and Dong-Hoon Park, Osan-si (Korea, Republic of)
Assigned to Samsung Electronics Co., Suwon-si, Gyeonggi-do (Korea, Republic of)
Filed on Oct. 04, 2005, as Appl. No. 11/242,080.
Claims priority of application No. 10-2005-0005401 (KR), filed on Jan. 20, 2005.
Prior Publication US 2006/0159487 A1, Jul. 20, 2006
Int. Cl. G03G 21/18 (2006.01)
U.S. Cl. 399—113 16 Claims
OG exemplary drawing
 
1. An image forming apparatus comprising:
a photosensitive drum, on which an electrostatic latent image is formed;
at least one developing cartridge including a developing roller which develops a toner image by supplying a developer to the electrostatic latent image; and
a transfer unit which transfers the toner images onto a print medium,
wherein the at least one developing cartridge comprises:
a first frame on which the photosensitive drum is arranged;
a second frame which is pivotably coupled to the first frame and coupled to the developing roller;
a first elastic element which provides an elastic force biasing the second frame in the direction towards the first frame; and
gap maintaining elements which limit the pivoting of the second frame so that a developing gap is maintained, and
the developing roller and the gap maintaining elements are arranged on the second frame to move in a direction opposite to a pivoting direction of the second frame.