Patent ID: 8213067
Filing Date: 2012-07-03
Classification: G02B,H04N

Abstract:
1. An optical scanning device that scans a scanning surface via a light flux, the optical scanning device comprising: a light source that emits a light flux; a pre optical system that is located on an optical path of the light flux from the light source and that includes at least one diffractive optical element having a diffractive surface on at least one side; a deflecting unit that deflects the light flux output from the pre optical system; and at least one scanning lens that focuses the light flux deflected by the deflecting unit on the scanning surface, wherein when an overall temperature of the optical scanning device rises during operation thereof, a temperature rise of the light source is smaller than a temperature rise of a scanning lens that is closest to the deflecting unit, and wherein a power of the diffractive surface is set such that if the temperature rise of the light source and the temperature rise of the scanning lens are assumed to be equal, a deviation amount of an in-focus position of the light flux via the diffractive optical element caused by the overall temperature rise is larger than a deviation amount of an in-focus position of the light flux via the scanning lens caused by the overall temperature rise.