| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress the occurrence of fogging in a white portion increased at the setting of an image forming mode, in which the circumferential speed of a photoreceptor drum is made low. <P>SOLUTION: In a plain paper mode, the circumferential speed of the photoreceptor drum is 160 mm/sec, the circumferential speed of a developing sleeve is 240 mm/sec, and the ratio of the circumferential speed of both of them is 1.5. In an OHT mode or the like, when the circumferential speed of the photoreceptor drum is set to 1/2, that is, 80 mm/sec, the ratio of the circumferential speed is set to 3 and is doubled, by using 2 being the invert of 1/2, and further it is set to 2.1 to 3.9, which is ±30% of 3. Thus, the ratio of the circumferential speed of the developing sleeve to the photoreceptor drum is made larger than that in the ordinary image forming mode, and the fogging in the white portion is maintained at an equal level to that in the plain paper mode. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
