Patent ID: 6529465
Filing Date: 2003-03-04
Classification: G11B

Abstract:
An optical system of an optical disk drive that at least one of reads data from an optical disk and writes data to the optical disk, comprising:a light source that emits a parallel laser beam; a deflector that has a rotatable mirror surface, said parallel laser beam emitted by said light source being incident on said rotatable mirror surface, said parallel laser beam being deflected from said rotatable mirror surface; an objective lens system that faces the optical disk; and a relay lens system provided between said deflector and said objective lens system, such that said rotatable mirror surface and a front principal plane of said objective lens system have a substantially conjugate relationship, wherein said relay lens system comprises a first relay lens group and a second relay lens group, said first relay lens group and said second relay lens group being arranged such that a front focal point of said first relay lens group is located in a vicinity of a central portion of said rotatable mirror surface on which said laser beam is incident, a rear focal point of said first relay lens group coinciding with a front focal point of said second relay lens group, and a rear focal point of said second relay lens group coincides with a front principal point of said objective lens system.