OPTICAL PICKUP AND OPTICAL ELEMENT USED THEREFOR

Title:

OPTICAL PICKUP AND OPTICAL ELEMENT USED THEREFOR

Document Type and Number:

WIPO Patent Application WO/1997/031371

Kind Code:

A1

Abstract:

A diffraction grating pattern is formed on a region other than a desired region provided in a substantially central portion of a double refraction plate, and this diffraction grating pattern comprises ion exchange regions having predetermined width, length and thickness and formed cyclically, and dielectric films formed on the upper surfaces of the ion exchange regions. The thickness of the ion exchange region and the thickness of the dielectric films are set so that ordinary rays of light advancing toward the double refraction plate pass through the diffraction grating pattern with a zero-order diffracted wave of extraordinary rays of light interrupted by the diffraction grating pattern. This enables an optical pickup contributing to the miniaturization of a reproducer and capable of being handled easily, and an optical element used therefor to be provided.

Inventors:

FUJITA MITSURU (JP)

Application Number:

PCT/JP1997/000464

Publication Date:

August 28, 1997

Filing Date:

February 20, 1997

Export Citation:

Click for automatic bibliography generation Help

Assignee:

TOYO COMMUNICATION EQUIP (JP)
FUJITA MITSURU (JP)

International Classes:

G02B5/04; G02B5/18; G02B5/30; G02B27/28; G02B27/40; G11B7/125; G11B7/1353; G11B7/1365; G11B7/139; G11B7/00; (IPC1-7): G11B7/135; G02B5/18; G02B5/30

Foreign References:

JPH02156205A	1990-06-15
JPH0331803A	1991-02-12
JPH05196813A	1993-08-06
JPH05120720A	1993-05-18
JPH06124477A	1994-05-06
JPH0765407A	1995-03-10
JPH0950648A	1997-02-18

Other References: