Patent ID: 7283765

Claim:
A developing device for an electrophotographic image forming apparatus, the developing device comprising: a developing roller configured and positioned to develop an electrostatic latent image formed on an electrophotographic photosensitive member; a magnet provided on an inner side of said developing roller and having a plurality of local maximum magnetic flux density positions in each of which a magnetic flux density is a local maximum on a peripheral surface of said magnet; a developing container supporting said developing roller; a seal member provided at an end portion in an axial direction of said developing roller, configured and positioned to prevent a developer supplied to said developing roller from leaking out of said developing container in the axial direction of said developing roller; a developer regulating member configured and positioned to regulate an amount of developer on the peripheral surface of said developing roller, said developer regulating member having an elastic portion abutting said developing roller and a supporting portion formed of a metal material and supporting said elastic portion; and a scraping member abutting said developing roller at an end portion in the axial direction of said developing roller, configured and positioned to collect the developer on the peripheral surface of said developing roller toward an inner side of said developing container in the axial direction, wherein, when said developing device is seen along the axial direction of said developing roller, said scraping member abuts said developing roller between a first position where the peripheral surface of said developing roller is crossed by a line which connects the supporting portion to the local maximum magnetic flux density position of the plurality of local maximum magnetic flux density positions that is nearest to said supporting portion, and a third position which is between the first position and a second position where said developing roller develops the electrostatic latent image and at which a line connecting a center of said developing roller and a local minimum magnetic flux density position crosses the peripheral surface of said developing roller, the local minimum magnetic flux density position being a position where the magnetic flux density is a minimum on the peripheral surface of said magnet.