Patent ID: 7075689
Filing Date: 2006-07-11
Classification: G02B

Abstract:
1. A scanning lens unit, which is disposed between an optical deflector for deflecting an incident laser light beam to a predetermined deflection direction at a constant angular speed and a surface to be scanned, and which includes plural lenses, wherein, when a reflective surface of said optical deflector is given by S wherein, when said laser light beam includes plural laser light components having different wavelengths and a wavelength of a j-th laser light component counted in ascending order from a first laser light component having a shortest wavelength, of said plural laser light components is denoted by λ is satisfied and centers of said lenses in a lens height direction are aligned with one another, where d assume that θ j denotes an angle of said laser light component having said wavelength λ j relative to a plane perpendicular to a rotational shaft of said optical deflector, and φ denotes a maximum value of a deflective surface tilt amount, which is a surface tilt amount relative to an ideal reflective surface, including tolerance in considerations of surface tilt of said reflective surface of said optical deflector and shaft tilt of said rotational shaft of said optical deflector.