Patent ID: 6266315
Filing Date: 2001-07-24
Classification: G11B

Abstract:
An optical focusing system for use with a light beam for forming a focused beam spot, the optical focusing system comprising:a refractive surface on one side of the optical focusing system and having a first radius of curvature;a first reflection surface on said one side, surrounding the refractive surface and having a second radius of curvature being different from the first radius of curvature;a transparent beam focusing surface on a side opposite said one side of the optical focusing system; anda second reflection surface on said side opposite said one side and surrounding the beam focusing surface,wherein the refractive surface refracts an incident light beam, the second reflection surface reflects light refracted by the refractive surface toward the first reflection surface, and the first reflection surface focuses light reflected from the second reflection surface on the beam focusing surface, as a focused beam spot.