Optical beam scanning device with hologram disc

摘要

A laser source and a converging lens are provided so that a laser beam emitted from the converging lens travels substantially parallel to the surface of a hologram disc. A incidence mirror is provided for causing the laser beam emitted from the lens to fall incident on the hologram disc at an angle of incidence of about 45 degrees. By merely moving or rotating the incidence mirror, the position of and the angle of incidence of laser beam to the hologram disc can be easily adjusted.