Light beam scanning apparatus.

摘要

In a light beam scanning apparatus using a hologram rotator (1), a post-hologram (9) is provided forfurther diffracting a light beam diffracted by the hologram rotatorto a direction opposite to that in which the light beam was first diffracted. By combining the kinds of wave fronts used for forming the holograms of the hologram rotator (1) and the post-hologram, the light beam scanning apparatus reduces deviation of the light beam scanning position caused by mode hopping of a laser diode, and an improved linear scanning of the light beam and/or image focusing characteristic is obtained.