Patent ID: 6115345
Filing Date: 2000-09-05
Classification: B82Y,G06K,G11B

Abstract:
A super-resolution optical head apparatus comprising:a first coherent light source for emitting a first coherent beam serving as a primary beam;a second coherent light source for emitting a second coherent beam which has a wavelength different from a wavelength of said first coherent beam;a phase plate for receiving said second coherent beam and emitting a subsidiary beam which has an intensity distribution in which peak values are placed at least on both sides of a center thereof on a plane perpendicular to an optical axis and a principal portion thereof is equal, or almost equal, in size to a principal portion of said primary beam;a focusing means for superimposing the primary beam emitted from said first coherent light source and the subsidiary beam emitted from said phase plate upon each other and focusing them onto an information storage surface having an optical information storage carrier;a control means for controlling said focusing means such that a light beam composed of said primary beam and said subsidiary beam being superimposed upon each other performs focusing and tracking with respect to the optical information storage carrier of said information storage surface;a wavelength separating means for receiving the light beam reflected from said information storage surface, separating said light beam into the primary beam and the subsidiary beam through wavelength separation, and emitting them;an optical detecting means for individually detecting an intensity of the primary beam and an intensity of the subsidiary beam and outputting a light intensity signal; anda calculating means for calculating, based on the light intensity signal outputted from said optical detecting means, a super-resolution scanning signal and outputting it.