Patent ID: 6473215
Filing Date: 2002-10-29
Classification: G02B

Abstract:
An optical scanner comprising:light deflector which scans by deflecting a light beam from a light source; and scanning lens optics for focusing the deflected light beam on a medium to be scanned; wherein said scanning lens optics includes more than one lens element, the angle of the line dropped normal to a first face of the lens element positioned the closest to the medium to be scanned which is directed to said light deflecting means at the point where the principal ray of a light beam incident at the scan start end crosses said first face is generally equal to the angle of the line dropped normal to the second face of said lens element which is directed to the medium to be scanned at the point where said principal ray crosses said second face, and the angle of the line dropped normal to said first face at the point where the principal ray of a light beam incident at the scan finishing end crosses said first face is generally equal to the angle of the line dropped normal to said second face at the point where said principal ray crosses said second face; wherein|P10/P|<0.02 and|P20/P|<0.02 where P10 is the axial power of said first lens face in the main scanning direction, P20 is the axial power of said second lens face in the main scanning direction, and P is the axial power of the scanning optics in the main scanning direction.