Patent ID: 7038822
Filing Date: 2006-05-02
Classification: B41J,G02B

Abstract:
1. An optical element for focusing an optical spot deflected by an optical deflector on a scanned surface in an optical scanner, comprising: a lens having a refractive index distribution, wherein: said lens, which serves as one component of an optical system in said optical scanner, is shaped in such a profile that misalignment of a focused position of said optical spot due to said refractive index distribution is corrected for image heights; said profile of the lens is configured to correct the misalignment of the focused position of the optical spot due to the refractive index distribution by decreasing a deviation of said misalignment of the focused position of the optical spot with respect to the image heights; and said lens is shaped such that a ratio F/W of deviation F (mm) of the misalignment of the focused position of the optical spot to an effective write width W (mm) scanned by said optical spot is less than or equal to 0.002.