| 摘要 |
PROBLEM TO BE SOLVED: To obtain highly accurate rotation of a polygon motor by guiding vertical air flow generated with the rotation of the polygon motor and reducing pressure fluctuation affecting the polygon motor, in a light beam scanner using a polygon mirror. SOLUTION: A first air flow guiding means is provided covering the upper part of the polygon mirror and having an opening each on the upper and the lower face. The opening on the lower face opens with an annular wall prepared in the entire circumferential direction of the polygon mirror, providing an air flow route in which the air flow can circulate between the upper face opening and the lower face opening. COPYRIGHT: (C)2007,JPO&INPIT |
