| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device which always obtains high image quality when switching the circumferential speed of a photoreceptor. SOLUTION: The circumferential speed of the photoreceptor is switched to two or more kinds of circumferential speeds within a prescribed range. The sleeves of a same-direction developing roll whose sleeve's rotating direction is the same as that of the photoreceptor and a reverse-direction developing roll whose sleeve's rotating direction is reverse to that of the photoreceptor in the developing device are rotated by driving systems independent respectively and a motor whose revolving speed can be varied. When the circumferential speed of the sleeve of the same-direction developing roll is defined as Va (m/sec), the circumferential speed of the sleeve of the reverse-direction developing roll is defined as Vw (m/sec), and the circumferential speed of the photoreceptor is defined as Vp (m/sec), the circumferential speeds of the sleeves of the same-direction developing roll and the reverse-direction developing roll are individually changed respectively in response to switching of the circumferential speed of the photoreceptor so that Va, Vw and Vp may satisfy prescribed relation. COPYRIGHT: (C)2008,JPO&INPIT |
