Title:
光ピックアップ装置及び対物レンズ
Document Type and Number:
Japanese Patent JP4595184
Kind Code:
B2
Abstract:
An optical pickup apparatus for first and second optical information recording medium, comprises first and second light sources to emit first and second light flux; a single objective lens made and a diaphragm having an aperture. The pitch of a plurality of ring-shaped diffractive zones provided on the objective lens, becomes gradually small from the optical axis to a point h and the pitch increases at the point h. At the time of conducting recording or reproducing information of the second optical information recording medium, the second light flux has a spherical aberration discontinuous portion at the point h where a spherical aberration-stepped amount is 7 mum to 40 mum, and a spherical aberration of a light ray of the second light flux having passed through the outermost portion of the aperture of the diaphragm is 7 mum to 40 mum.
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Inventors:
Shinichiro Saito
Katsuya Sakamoto
Katsuya Sakamoto
Application Number:
JP2000302749A
Publication Date:
December 08, 2010
Filing Date:
October 02, 2000
Export Citation:
Assignee:
Konica Minolta Holdings Co., Ltd.
International Classes:
G02B5/18; G02B13/00; G11B7/135; G02B13/18; G11B7/125; G11B7/1275; G11B7/1353; G11B7/1374; G11B7/1392; G11B7/00
Domestic Patent References:
| JP2001249273A | ||||
| JP2001235676A | ||||
| JP2002074725A |