Polygonal mirror group for precision high-speed scanning device e.g. in laser printer - has polygonal mirror lying at centre of bearing with mirror surfaces symmetrical to axis defined by end faces

摘要

The polygonal mirror group has the mirror surfaces around its periphery lying symmetrical to an axis, defined by the end faces, at least one of which is in the shape of a skull cap. Pref. the polygonal mirror group has a polygonal mirror made of optical glass, a bearing and an electric motor drive, the polygonal mirror lying at the centre of the bearing. The end faces may be bi-convex, plano-convex, or plano-concave. The mirror surfaces pref. have interference coatings with different wavelengths. ADVANTAGE - Ensures high tolerances.