| 摘要 |
PURPOSE:To easily form a mirror which is not varied in film thickness in the upper stage and the lower stage by forming the upper and the lower reflecting parts of the polygon mirror as separated bodies, bring a reflecting material to vapor-deposition and forming the reflecting surface, and thereafter, coupling the upper and the lower reflecting parts. CONSTITUTION:The upper stage reflecting part 6b and the lower stage reflecting part 6a are formed as separated bodies, a reflecting material is brought to vapor-deposition to each of them and the reflecting surface is formed, and thereafter, by coupling them, a rotary polygon mirror 6 is assembled. In such a manner, the mirror is divided into the upper stage reflecting part 6b and the lower stage reflecting part 6a and each of them is brought to vapor- deposition, therefore, adhesion angles can be made almost the same, the film thickness becomes constant and the reflection characteristics is also equalized. At the time of assembling, the lower stage reflecting part 6a is fitted into the rotor 7a of a polygon motor 7, and subsequently, the upper stage reflecting part 6b is set thereon, and a plate spring 65 is clamped to a shaft 70 with a set screw 66 through a rubber seal 64, by which the upper and the lower reflecting parts 6a,6b are fixed to the rotor 7a. |
