| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an objective lens for optical disk in accordance with a double-sided aspheric single lens having numerical aperture NA of ≥0.75 and superior in axial aberration, off-axis aberration, and eccentricity aberration between both sides. <P>SOLUTION: The objective lens for optical disk is the single lens having aspheric both sides and numerical aperture NA of ≥0.75, and has the optical characteristics in which an angle u1' defined by the optical axis and a light ray having the maximum height inside the lens satisfies expressions of (1-D)sin(K)<sin(u1')<(1+D)sin(K), K=(0.60866-0.11t/f-0.1272d/f)(0.83+0.2NA)NA/0.85, where f is the focal length of the lens, t is the thickness of the center of the lens, d is the thickness of a transmission layer of the optical disk which is irradiated with the light through the lens, and D is 0.06. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
