OPTICAL SCANNER AND IMAGE FORMATION APPARATUS

摘要

PROBLEM TO BE SOLVED: To improve a dustproof performance without applying a strong force to a substrate.SOLUTION: A laser holder 50 is provided with a cylinder part for guiding a light beam emitted from a laser emission source 92. A cylinder part of the laser holder 50 is inserted into a seal member 67 which has a small diameter part 68 in contact with the cylinder part so as to surround an outer periphery of the inserted cylinder part and a large diameter part 69 having a larger opening area than the small diameter part 68, in contact with a laser substrate 54 to surround a mounting part on the laser substrate for a laser emission source 92, and connecting to the small diameter part 68. The large diameter part 69 includes a thin wall part 71 that intersects with a travelling direction of a light beam emitted from the laser emission source 92. The bending of the thin wall part 71 adjusts a distance between the small diameter part 68 and the large diameter part 69 to be a distance corresponding to that between the laser substrate 54 and the laser holder 50.