| 摘要 |
PURPOSE:To give magnetic action from the outside of casign and make possible manual rotation by using a non-magnetic hermetic casing and beforehand equipping magnets or the like to the rotating portions which rotate integrally with the revolving shaft of a rotary polyhedral mirror so as not to break balance. CONSTITUTION:A casing 7 is a perfect hermetic structure composed of non-magnetic material. Inside is supported a rotary polyhedral mirror 8 by a bearing 10 and the mirror is driven by a motor 11. The rotary polyhedral mirror 8 consists of a mirror mounting body 8a of regular octagonal columnar form and the mirrors 8b mounted on the peripheral surfaces of the side thereof. Small pieces 15, 16 composed of magnets or magnetic materials are buried in the mirror mounting body 8a. These small pieces 15, 16 are made to the same weight and same shape by taking the balance in the rotation of the mirror mounting body 8a into consideration. On the other hand, a pin 21 is beforehand secured to the part right above the revolving shaft 9 of the top face 7a of the casing 7. Manual rotating of the rotary polyhedral mirror 8 is accomplished by fitting the hole 23 of the magnetized manual turning piece 22 onto this pin 21 and turning the manual turing piece 22 by hand. Then, magnetical force acts between the small pieces 15, 16 and the manual turning piece 22 and the rotary polyhedral mirror 8 turns together with the manual turning piece 22. |
