| 摘要 |
<P>PROBLEM TO BE SOLVED: To properly remove foreign matter adhering to the circumferential surface of a positioning roller. <P>SOLUTION: A developing device 20 configured so that developer is supplied to a photoreceptor drum 121, arranged so as to face a second developing roller 42 by the rotation of the second developing roller 42 around a second roller shaft 421 is provided with the positioning roller 60, which is externally fitted to both end portions of the second roller shaft 421 to be concentric and relatively rotatable, and whose diameter is larger than that of the second developing roller 42; a cleaning film 82, which is provided to a housing 21 and whose top edge portion faces the circumferential surface of the positioning roller 60; and a contact and separation mechanism 70 which changes the position of the second developing roller 42, in between a close position T1, where the second developing roller 42 comes close to the photoreceptor drum 121 to bring the circumferential surface of the positioning roller 60 into contact with the circumferential surface of the photoreceptor drum 121, and simultaneously into contact with the top edge portion of the cleaning film 82 and a separated position T2, where the second developing roller 42 is away from the photoreceptor drum 121 to eliminate the contact of the circumferential surface of the positioning roller 60 with the cleaning film 82. <P>COPYRIGHT: (C)2008,JPO&INPIT |
