Patent ID: 7277659

Claim:
An electrophotographic image forming apparatus for forming an image on a recording material, comprising: a) a main assembly to which a cartridge is detachably mountable, the cartridge including: a developer accommodating portion configured to accommodate a developer for developing an electrostatic latent image formed on an electrophotographic photosensitive member; a developing roller configured and positioned to develop an electrostatic latent image with the developer; a developer supply opening configured and positioned to supply the developer to the developing roller from the developer accommodating portion; and a sealing member configured and positioned to unsealably seal the developer supply opening over a range from one longitudinal end to the other longitudinal end of the developer supply opening, with respect to a longitudinal direction of the developing roller; b) first developer detecting means for detecting whether the amount of the developer deposited on a member to be detected is less than a predetermined level adjacent to the one longitudinal end; c) second developer detecting means for detecting whether the amount of the developer deposited on a member to be detected is less than a predetermined level adjacent to the other longitudinal end; and d) discriminating means for descriminating a state of the sealing member on the basis of a result of detection of said first developer detecting means and said second developer detecting means.