Invention Grant
US08995246B2 Optical head, objective lens, optical disc device, computer, optical disc player, and optical disc recorder 有权
光头,物镜,光盘装置,计算机,光盘播放器和光盘记录器

Optical head, objective lens, optical disc device, computer, optical disc player, and optical disc recorder
Abstract:
An objective lens (101) is configured to converge laser light of a first wavelength λ1 (390 [nm]≦λ1≦430 [nm]), laser light of a second wavelength λ2 (630 [nm]≦λ2≦680 [nm]), and laser light of a third wavelength λ3 (750 [nm]≦λ3≦810 [nm]) on an information recording surface of a first information recording medium, an information recording surface of a second information recording medium, and an information recording surface of a third information recording medium, and is configured such that the distance from a convergent point of normal diffracted order light, to a virtual collecting point formed by virtual diffracted order light between the convergent point of normal diffracted order light and a collecting point of unwanted diffracted order light is twice or more of the pull-in range of a focus error signal to be obtained in recording or reproducing information with respect to the third information recording medium.
Information query
Patent Agency Ranking
0/0