Patent ID: 6052355
Filing Date: 2000-04-18
Classification: G11B

Abstract:
An optical pickup apparatus for reading information from one of different kinds of optical information recording medium, each having a transparent base board in different thickness, or for recording information onto one of said different kinds of optical information recording medium, comprising:a laser light source;a light converging optical system for converging luminous flux from said laser light source through said transparent base board of said optical information recording medium onto an information recording surface of said optical information recording medium;a changing means for changing an optical path of said luminous flux, being reflected on said information recording surface, to be different from an optical path of said luminous flux, being emitted from said laser light source;an photo-detecting means for detecting said luminous flux being reflected on said information recording surface; anda compensation means, provided between said changing means and said photo-detecting means, for correcting spherical aberration of said luminous flux, being reflected on said information recording surface and passed through said changing means, when one of said different kinds of optical information recording medium is subjected to recording or reading information.