| 摘要 |
PROBLEM TO BE SOLVED: To provide a mechanism for fixing on a frame a lens for focusing a laser beam deflected with a rotating polygon mirror onto the surface of a photoreceptor, the mechanism with which the lens is excellently mounted on the frame while eliminating an adverse effect in an assembly process. SOLUTION: A cylindrical lens 64b is formed with a recessed part 78b at the central part in a main scanning direction on the emitting face from which a laser beam is emitted in the non-transmissive region which is shifted to the casing side from the transmissive region in which the laser beam passes. The casing supporting a polygon mirror is provided with an engaging nail 74b fixed on the supporting face 80b. When the cylindrical lens 64b is fixed, the engaging nail 74b is engaged with the recessed part 78b, and the central part in the main scanning direction of the cylindrical lens 64b is fixed, thus, the central part in the main scanning direction of the cylindrical lens 64b is prevented from moving in a subscanning direction. COPYRIGHT: (C)2005,JPO&NCIPI |
