Light beam scanning apparatus.

摘要

At least one plane diffraction grating (3) is formed on a rotatable plate (1), and a light beam (7) is made to impinge upon the plane diffraction grating (3) so that the plane of incidence is a plane in which the rotation axis (2) of the rotatable plate (1) lies. The light beam (8a) diffracted by the plane diffraction grating (3) is reflected at least by use of a plane reflection surface and guided again (9, 10) to the plane diffraction grating (3). The light beam (11a) diffracted again by the plane diffraction grating (3) is focused by a focusing lens (13) onto a scanning surface (14), so that the scanning surface (14) is scanned with the focused light spot along a bow-free straight scan line (15) as the rotatable plate (1) is rotated.