| US 7,573,800 B2 | ||
| Optical pickup and optical disk apparatus | ||
| Masaharu Fukakusa, Kobayashi (Japan); Mitsuhiro Matsumoto, Arao (Japan); Jiro Mimasa, Tamana (Japan); Hiroshi Tanigawa, Kumamoto (Japan); Hiroshi Kamei, Tamana (Japan); Toshiharu Kimura, Tamana (Japan); Mitsugu Adachi, Tamana (Japan); Hiroshi Iwabuchi, Oonojou (Japan); and Eiichiro Nakao, Kurume (Japan) | ||
| Assigned to Panasonic Corporation, Osaka (Japan) | ||
| Filed on Jan. 28, 2005, as Appl. No. 11/44,633. | ||
| Claims priority of application No. P2004-021088 (JP), filed on Jan. 29, 2004; application No. P2004-022896 (JP), filed on Jan. 30, 2004; application No. P2004-030338 (JP), filed on Feb. 06, 2004; application No. P2004-030339 (JP), filed on Feb. 06, 2004; application No. P2004-103803 (JP), filed on Mar. 31, 2004; application No. P2004-131006 (JP), filed on Apr. 27, 2004; and application No. P2004-147452 (JP), filed on May 18, 2004. | ||
| Prior Publication US 2005/0169151 A1, Aug. 04, 2005 | ||
| Int. Cl. G11B 7/00 (2006.01) | ||
| U.S. Cl. 369—112.19 [369/44.12] | 5 Claims |
| 1. An optical pickup comprising:
a light source emitting plural light beams of mutually different wavelengths;
a diffraction member that diffracts said light beams;
a beam splitter that receives diffracted light beams from said diffraction member and that reflects some of the diffracted
light beams and transmits some of the diffracted light beams;
a light-receiving element that receives the reflected light beams from said beam splitter; and
a coupling base having a penetrating hole and supporting the light source, the diffraction member and the light-receiving
element,
wherein the beam splitter is spaced apart from the penetrating hole of the coupling base and the diffraction member,
wherein the plural light beams emitted from the light source enter the diffraction member and the beam splitter through the
penetrating hole,
wherein a light entering the beam splitter from the exterior enters the light-receiving element through the beam splitter,
and
wherein:
the beam splitter guides the plural light beams from the light source toward an optical disk and a light reflected from the
optical disk to the light-receiving element;
the beam splitter includes therein at least first and second inclined faces, inclined to an incident direction of the light
to the beam splitter;
the first inclined face has a first polarizing beam-splitting portion;
the second inclined face has a second polarizing beam-splitting portion;
the first polarizing beam-splitting portion has a polarizing property to a light of a short wavelength;
the second polarizing beam-splitting portion has a polarizing property to a light of a long wavelength;
within lights of a short wavelength and a long wavelength emitted from the light source, a P-wave component is transmitted
in the first and second polarizing beam-splitting portions and guided toward the optical disk;
within the light of the long wavelength reflected from the optical disk, an S-wave component is reflected by the second polarizing
beam-splitting portion to reach the light-receiving element;
within the light of the short wavelength reflected from the optical disk, an S-wave component is transmitted by the second
polarizing beam-splitting portion; and
within the light of the short wavelength transmitted by the second polarizing beam-splitting portion, an S-wave component
is reflected by the first polarizing beam-splitting portion to reach the light-receiving element.
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