| 摘要 |
PURPOSE: To reduce the number of parts of a supporting mechanism for a rotary polygon mirror in a rotary shaft by fitting the rotary polygon mirror to a rotary member between an engaging part of one end side of the rotary member and a receiving member of another end side, engaging an inside projection part of an elastic member with the engaging part and pressing the rotary polygon mirror to the receiving member by an outside projection part. CONSTITUTION: The rotary shaft 2 is exposed from a housing case 3 to the outside, and a recessed part 4 being the engaging part is formed near the top end of the shaft 3. Further, the rotary polygon mirror 6 is fitted to the rotary shaft 2 so as o be come into contact with the upper surface of the receiving member 5. By fitting a part projecting inward among a curve part of an elastic wire rod 7 being the elastic member to the recessed part 4 provided on the rotary shaft 2 is the state pushing and spreading the part, the elastic wire rod 7 is held by the rotary shaft 2 with the elastic force of the elastic wire rod 7. Simultaneously, the part projecting outward in the elastic wire rod 7 is pushed to the upper part of the rotary polygon mirror 6, so that the rotary polygon mirror 6 is pressed on the receiving member 5 by the elastic force of the elastic wire rod 7. |
