Objective lens for optical disk system and optical head using th

Details Objective lens for optical disk system and optical head using th Objective lens for optical disk system and optical head using th

1989-04-26

1990-05-22

Dzierzynski, Paul M.

G02B 1318

Patent

active

049272470

ABSTRACT:
A lens controls the chromatic aberration of an objective lens for practical use in an optical disk system. The lens has first and second aspherical surfaces each providing a positive refractive power for focusing a light through a transparent plate and satisfies a condition: ##EQU1## where f.sub.L =focal length of the lens, d.sub.c =thickness of the transparent plate, n.sub.c =refractive index of the transparent plate, .lambda.=center wavelength of the light, NA=numerical apperture of the lens, .nu..sub.L =local dispersion of the lens, and .nu..sub.c =local dispersion of the transparent plate. The local dispersion of each element is expressed by: ##EQU2## where n.sub.80 is refractive index at a center wavelength .lambda. nm, n.sub..lambda. +5 a refractive index at .lambda.+5 nm, and n.sub..lambda. -5 a refractive index at .lambda.-5 nm.

REFERENCES:
patent: 4027952 (1977-06-01), Hugues
patent: 4449792 (1984-05-01), Arai et al.
patent: 4571034 (1986-02-01), Nakamura
patent: 4655556 (1987-04-01), Kajitani
patent: 4765723 (1988-08-01), Takamura
patent: 4768867 (1988-09-01), Suda
patent: 4842388 (1989-06-01), Tanaka et al.

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