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Title:
OPTICAL PICKUP AND OPTICAL DISK DEVICE
Document Type and Number:
Japanese Patent JP3697875
Kind Code:
B2
Abstract:

PROBLEM TO BE SOLVED: To constitute a small-sized and inexpensive pickup and to perform a precise servo.
SOLUTION: A light separation means of an optical pickup l is a hologram element 22, and the hologram element 22 is provided with a first diffraction grating 25 and an optical path branch part 26 consisting of plural surfaces having normal vectors different from each other on its light source side surface, and is provided with a second diffraction grating 27 consisting of a continuous area on its optical disk side, and is constituted so that the first diffraction grating 25 divides the light from the light source to a main beam and a side beam, and the second diffraction grating 27 passes the light from the light source through, and diffracts the return light from the optical disk toward the optical path branch part 26. Further, the optical path branch part 26 divides the return light from the optical disk to lead it to respective light receiving parts 24a (A-D), B, F of a photodetector 24.


Inventors:
今井 聡
遊馬 嘉人
Application Number:
JP1997000357372
Publication Date:
September 21, 2005
Filing Date:
December 25, 1997
Export Citation:
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Assignee:
ソニー株式会社
International Classes:
G11B7/123; G11B7/131; G11B7/135; G11B7/1353; G11B7/1356; G11B7/1381; G11B7/12; G11B7/13; (IPC1-7): G11B7/135
Domestic Patent References:
JP1146143A
JP64055752A
JP64004926A
JP57105832A
JP4102239A
JP9027139A
JP61189416U
Attorney, Agent or Firm:
小池 晃
田村 榮一
伊賀 誠司