ELECTROPHOTOGRAPHIC IMAGE FORMING DEVICE AND DEVELOPING CARTRIDGE

摘要

PROBLEM TO BE SOLVED: To make the direction in which the electrode of a magnet faces an electrophotograhic photoreceptor drum stay almost the same by regulating the direction of the magnet when a developing device has shifted a developing position. SOLUTION: Nearly in the middle of a connection arm 7a connected with the magnet, a slide hole 19 is made along the arm 7a. The connection projection 20 of a support arm 7b is connected with the slide hole 19 by being fitted in it. The rotation center of the connection arm 7a and the rotation center P of the magnet are identical. The external edge 21 of the free end of the connection arm 7a is on a straight line La passing through the rotation center P of the magnet and highly accurately coincides with the straight line La forming a set angle Z with the direction extending toward a developing pole from the point P. The connection arm 7a strikes against a position reference pin 8 fixed to a device main body on the straight line La on the external part 21. In the case, the position of the developing pole of the magnet is set so as to be matched with the direction extending toward the rotation center O of the photoreceptor drum 3 from the point P.