| 摘要 |
<p>PURPOSE:To miniaturize a photosensitive drum, and also to maintain a distance between the drum and an exposure means with accuracy by effectively using a stator and a rotor for a motor and firmly fixing the stator on the exposure means, and the rotor on the photosensitive drum respectively. CONSTITUTION:An ultrasonic motor 40 is constituted of the stator 4a constituted of two piezoelectric ceramics 42 and an elastic body 43, and the rotor 4b constituted of a lining material 44 and a rotary body 45, and by impressing an AC voltage whose phase is shifted by 90 deg. in terms of time on the piezoelectric ceramic 42, a progressive wave is excited on the elastic body 43 so as to rotate the rotary body 45 in a direction reverse to that of the progressive wave through the lining material 44. A fixing table having a shaft fit-in part 41 on its center is attached on the end surface side of the piezoelectric ceramic 42 so as to fit and fix a unit shaft 3 in the shaft fit-in part 41. On the other hand, a disk- like supporting ring body 46 whose outside diameter is set equal to the inside diameter of the drum 1 is attached on the end surface on the side of the rotary body 45, and the inside diameter of the drum 1 is made to fit in the outer circumferential surface of the supporting ring body 46 so as to be fixed.</p> |
