| 摘要 |
PURPOSE:To offer an image forming device equipped with a rotary polygon mirror which can be produced without damaging a mirror surface. CONSTITUTION:By arranging the rotary polygon mirror 32 whose plane tilt angle of respective mirror surfaces is theta so that the rotary shaft of the mirror 32 may be orthogonally crossed with a horizontal scanning plane, the respective mirror surfaces having the plane tilt angle theta are inclined by the angle theta with respect to the horizontal scanning plane A. The incident angle of a light beam from a semiconductor laser 30 on the mirror surface of the mirror 32 is shifted by 2theta with respect to the plane A. Thus, the rotary polygon mirror whose light reflection mirror surface is not damaged is easily produced and the reliable image forming device equipped with the rotary polygon mirror is obtained. |
