Patent ID: 7391542
Filing Date: 2008-06-24
Classification: H04N

Abstract:
1. An optical scanning apparatus comprising: a deflecting unit comprised of a rotary polygon mirror for deflecting a light beam emitted from a light source unit; and a scanning optical system for guiding the light beam deflected by the deflecting unit to a surface to be scanned; wherein a condition written as: where D (mm) is a diameter of a circumscribed circle of the rotary polygon mirror, M is the number of deflecting facets of the rotary polygon mirror, {acute over (α)} (rad) is an incident angle of the light beam on the deflecting facet at the time when the light beam scans a scanning center, θ (rad) is a maximum swing angle of the deflecting facet at the time when an effective scanning range is scanned, and β is a magnification of the scanning optical system in a sub scanning section is satisfied.