| 摘要 |
PROBLEM TO BE SOLVED: To make a gap between an electrifying roller and a photoreceptor drum almost uniform even when an electrifying roller is rotated, via a transmis sion gear, by a driving gear on the photoreceptor drum side. SOLUTION: Urging force of a press spring 19a on the side of the transmission gear 62, which urges the electrifying roller 14 to the photoreceptor drum 5, is made greater than urging force of a press spring 19b. Thus, even in the case the transmission gear 62 is rotated by a driving gear 61 which rotates as the photoreceptor drum 5 rotates, and consequently a component force Fa in a direction away from the driving gear 61 acts on the transmission gear 62, movement of the transmission gear 62 in the direction of the component force is hindered by the press spring 19a having greater urging force. Hence, the gap between the electrifying roller 14 and the photoreceptor drum 5 is made almost uniform over the entire area in which electrification is effective. |
