| 摘要 |
PURPOSE:To prevent color slippage and image jitters with simple structure and in an inexpensive method by driving a transfer drum and a photosensitive belt with independent motors and mechanical reduction gears, respectively and composing the mechanical reduction gear of a specific helical gear. CONSTITUTION:When a photosensitive belt 2, a transfer drum 4, a developing unit 3, and a fed paper fixing unit 15, are driven by the independent motors and the mechanical reduction gears, respectively, an action so as not to apply the vibrations of the developing unit 3 and the the fed paper fixing unit 15, to the photosensitive belt 2 and transfer drum 4, which require performance for low rotational irregularities, is obtained. On the other hand, as the gears 29, 30, 32, and 33 of the mechanical reduction gear driving the photosensitive belt 2, and the transfer drum 4, the helical gear is used, and the rate of the engagement of the helical gear is set <=1.0. Thus, irregularities in a rotation caused by the engagement of the tooth of the gears are reduced, and the performance for the low rotational irregularities, equal to that of a direct driving system, or more, can be obtained. |
