Title:
DIFFRACTIVE ELEMENT AND LIGHT PICKUP DEVICE
Document Type and Number:
WIPO Patent Application WO/2011/065277
Kind Code:
A1
Abstract:
Disclosed is a light pickup device using a light source wherein three semiconductor lasers are contained within one package. A light pickup device uses a diffractive element wherein even if an offset occurs between a light emitting point of a beam of a wavelength λ1 and light emitting points of beams of wavelengths λ2 and λ3, in order to allow each beam to impinge upon a suitable location of a light receiving surface of a light detector, the beam of the wavelength λ1 in an optical path is allowed to pass unmodified, while for the beam of the wavelength λ2 and the beam of the wavelength λ3, a diffraction groove is formed wherein the laser receiving locations shift from P2 and P3 to P2' and P3' according to a relative distance from the light detector.
Inventors:
KIMURA TOHRU (JP)
Application Number:
PCT/JP2010/070553
Publication Date:
June 03, 2011
Filing Date:
November 18, 2010
Export Citation:
Assignee:
KONICA MINOLTA OPTO INC (JP)
KIMURA TOHRU (JP)
KIMURA TOHRU (JP)
International Classes:
G11B7/125; G11B7/135; G11B7/13
Foreign References:
| JPH11134702A | 1999-05-21 | |||
| JP2005327387A | 2005-11-24 | |||
| JP2008041234A | 2008-02-21 | |||
| JP2008052826A | 2008-03-06 |
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