| 摘要 |
PURPOSE:To reduce windage loss, to reduce heat and noise generation, and to improve motor efficiency by making a screw, which fixes the polygon mirror, not project from the surface of a rotary body. CONSTITUTION:A balance correction groove 16 is formed along the inner peripheral surface of a mirror presser 19 which holds a polygon mirror 5, and a screw hole wherein a fitting screw 7 for fixing the mirror presser 19 to a hollow rotary shaft 3 is fitted is formed in the top surface. An annular projection 20 which has a back facing hole 191 wherein the head part 71 of the fitting screw 7 can all be fitted, above said screw hole is formed on the top surface of the mirror presser 19. |
