| 摘要 |
<p>PROBLEM TO BE SOLVED: To avoid a noise and a resonance frequency caused by abrasion and vibration even in either mode, and prevent the deterioration of image quality and the jitters by changing the gear ratio to transmit motive power to a roller at normal rotation time and reverse rotation time of a driving motor. SOLUTION: A swing gear 4 to which a swing arm 3 is connected as a transmission switching means, meshes with a two-stage reduction gear 2 to receive transmission of motive power of a stepping motor 1, and in a normal mode, the stepping motor 1 normally rotates, and the reduction gear 2 reversely rotates, and the swing gear 4 connected by the swing arm 3 turns upward, and meshes with a large gear of a first driving speed reduction gear 6. In a fine mode, the stepping motor 1 reversely rotates, and the reduction gear 2 normally rotates, and the swing gear 4 turns downward, and meshes with a large gear of a second driving speed reduction gear 13. The gear ratio of a gear set in the fine mode is changed from the gear ratio of a gear set in the normal mode, and rotating speed to the stepping motor 1 and step control are the same.</p> |
