Abstract: A deflecting/scanning apparatus includes a deflector for deflecting/scanning a light beam from a light source unit, an optical system for focusing the light beam deflected/scanned by the deflector onto a surface, an optical box for accommodating the deflector and the optical system, and a cover for covering the optical box. An elastic member is disposed in the optical box so as to blocking flow of air entering therein. At least a portion of the elastic member is fitted in a recess portion formed on at least one of the optical box and the cover so that the elastic member is pressed by the cover.

Abstract: A cam sleeve for axially moving a lens as it rotates about an optical axis is provided with a pair of camming grooves that depict the same locus. And, a holding member for the lens to be guided by a guide member is provided with a pair of pins corresponding to the pair of camming grooves. These pins engage in the pair of camming grooves to achieve good stability of movement of the lens when the cam sleeve rotates.