Objective lens and optical pickup device
AssigneePanasonic Intellectual Property Management Co., Ltd.
InventorsKazuhiro Minami, Yasuhiro Tanaka
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Abstract
An objective lens capable of converging light of a used wavelength with a satisfactory aberration on a recording medium is provided. An objective lens for converging light of a predetermined wavelength λ on a recording medium satisfies the following condition: |CML|+|CMF|<0.03 λ, where CML is an amount of a generated third-order coma aberration per 1 degree of tilt of the objective lens, and CMF is an amount of a generated third-order coma aberration per 1 degree of tilt of off-axis light.
Claims7
An objective lens for converging light of a predetermined wavelength λ on a recording medium, the objective lens satisfying the following condition:
- |CMD|<0.02 λ
- 0.02 λ<|CML|<0.2 λ
- where
- CML is an amount of a generated third-order coma aberration per 1 degree of tilt of the objective lens, and
- CMD is an amount of a generated third-order coma aberration per 1 degree of tilt of the recording medium.
An optical pickup device including:
- a light source for emitting light of a predetermined wavelength λ;
- and
- an objective lens for converging the light on a recording medium, wherein:
- the objective lens satisfies the following condition:
- |CMD|<0.02 λ
- 0.02 λ<|CML|<0.2 λ
- where
- CML is an amount of a generated third-order coma aberration per 1 degree of tilt of the objective lens, and
- CMD is an amount of a generated third-order coma aberration per 1 degree of tilt of the recording medium.
Dependencies are inferred from the claim text.