Optical scanner using rotating mirror - has narrow cylindrical surface on rotor and equally-spaced flat facets

摘要

The optical scanning device uses a rotating mirror (14). At the bottom of the mirror assembly there is a narrow cylindrical reflecting surface. Above this narrow reflecting surface there is a polygonal body which may have 6 flat sides or a larger number, eg. 12 flat sides. The light (10a) from a source of parallel light passes through a lens (11) which focusses it (12) onto the narrow mirror (13). Diverging light (10c) leaving the narrow mirror falls on a concave mirror (16). The focal length of this mirror is chosen to give a parallel beam (10d) which falls on the flat facets (17) of the polygonal mirror. As the mirror assembly (14) rotates, a series of beams scanning in one direction is produced.