| 摘要 |
A damping member is disposed between a motor cover attached near a rotary polygon mirror drive motor so as to cover a rotary polygon mirror and an optical cover attached to an optical box so as to cover the motor cover and a (f - &thetas;) optical lens group. The damping member can absorb a vibration generated in the motor cover when the rotary polygon mirror and the rotary polygon mirror drive motor are driven to thereby alleviate a transmission of a vibration to the optical cover. Furthermore, a heat generated from the rotary polygon mirror drive motor is radiated from the optical cover through the damping member to thereby prevent a heat from being filled in the inside of the optical cover. In this way, it is possible to avoid the vibration and the heat from affecting the (f - &thetas;) lens group or the like as much as possible. Thus, the light beam can be focused on the photosensitive material under satisfactory condition. <MATH> |
