Polygon mirror

A polygon mirror comprising:

• a plurality of reflecting surfaces each of which is rectangular,
• wherein following inequalities are satisfied:
• 0.02<|1−B/A|<0.10, and
• 0.2≤s/L≤0.8
• where A represents a reflectivity at a center of each of the plurality of reflecting surfaces with respect to a light flux which is incident at a predetermined incident angle, B represents the reflectivity at a predetermined point between the center and an end in a longitudinal direction of each of the plurality of reflecting surfaces with respect to the light flux which is incident at the predetermined incident angle, L represents a distance between the center and the end of each of the plurality of reflecting surfaces, and s represents a distance between the center and the predetermined point of each of the plurality of reflecting surfaces.

A light scanning apparatus comprising:

• a polygon mirror including a plurality of reflecting surfaces each of which is rectangular;
• and
• an optical system for guiding the light flux deflected by the polygon mirror to a scanned surface,
• wherein a following inequality is satisfied:
• 0.02<|1−B/A|<0.10
• where A represents a reflectivity at a center of each of the plurality of reflecting surfaces with respect to a light flux which is incident at a predetermined incident angle, and B represents the reflectivity at a predetermined point between the center and an end in a longitudinal direction of each of the plurality of reflecting surfaces with respect to the light flux which is incident at the predetermined incident angle, and
• wherein the predetermined point is a reflection point of a marginal ray of an outermost off-axis light flux most distant from the center in the longitudinal direction.