Patent ID: 9019333
Filing Date: 2015-04-28
Classification: G02B

Abstract:
1. An optical scanning apparatus, comprising: a light source; and a rotational polygon mirror having N reflecting surfaces, the rotational polygon mirror being configured to reflect a light flux emitted from the light source so that a scanning surface is scanned along a main-scanning direction with the light flux reflected from the rotational polygon mirror, wherein a width of the light flux incident on the rotational polygon mirror in a direction corresponding to the main-scanning direction is smaller than a width of each reflecting surface of the rotational polygon mirror in the direction corresponding to the main-scanning direction, and is satisfied in a plane orthogonal to a rotational axis of the rotational polygon mirror, where R is a radius of a circumscribing circle of the rotational polygon mirror, d in is a width of the light flux incident on the rotational polygon mirror in the direction corresponding to the main-scanning direction, θ in is an incident angle of the light flux with respect to a reference axis direction, the reference axis direction being orthogonal to the rotational axis of the rotational polygon mirror, where θ s is an angle of view at a scanning start position, and θ e is an angle of view at a scanning end position in a scanning region.