Patent ID: 6266314
Filing Date: 2001-07-24
Classification: G11B

Abstract:
An optical pickup device for recording information onto and/or reading out information from an optical recording medium that is positioned at a recording medium positioning area of an optical recording and/or reproducing apparatus, said device comprising:a first light beam source for emitting a first light beam to impinge upon and be reflected by a recording medium positioned at the recording medium positioning area,a second light beam source for emitting a second light beam to impinge upon and be reflected by a recording medium positioned at the recording medium positioning area,a light beam detector for receiving at least one of the first and second light beams after being reflected by a recording medium at the recording medium positioning area so that the information is read from the at least one of the first and second light beams after being reflected,a light beam diameter changing rate adjusting member to adjust a changing rate of a diameter of either of the first and second light beams, wherein the light beam diameter changing rate adjusting member has an exposed surface through which the either of the first and second light beams passes, and a refractive index of a substance contacting the exposed surface is smaller than that of the light beam diameter changing rate adjusting member.