Patent ID: 8000630

Claim:
A developing cartridge detachably mountable to an image forming apparatus main body having main body side guide portions and a developing cartridge mounting portion to which the developing cartridge is detachably mountable, the developing cartridge comprising: a developer containing portion for containing a developer; a developing roller for forming a developer image using the developer; first developing cartridge side guide portions provided at one end and the other end, respectively, in a longitudinal direction of the developing roller, for engaging with the main body side guide portions to regulate a movement locus of the developing cartridge when the developing cartridge is mounted to the image forming apparatus main body; and protruding portions provided at the one end and the other end, respectively, in the longitudinal direction of the developing roller, wherein the developing cartridge is mounted to the image forming apparatus main body in a mounting direction intersecting with the longitudinal direction of the developing roller with the developing roller being a leading edge, and wherein the protruding portions protrude on a downstream side further than the developing roller in the mounting direction, and the protruding portions are second developing cartridge side guide portions for engaging with the main body side guide portions to regulate the movement locus of the developing cartridge when the developing cartridge is mounted to the developing cartridge mounting portion.