Patent EP0278406A2 successfully refreshed from Google Patents.
EP0278406A2
Expired / Lapsed
EP
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Optical pickup head
Assignee: Sony Corp
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Filing: 1988-02-04
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Granted: —
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Expires: 2008-02-04
Abstract
Abstract An optical pickup head comprising a substrate (1) on which an optical sensor (2) is formed, and an optical member (4) adhered on said optical sensor (2) on said substrate (1) by an adhesive (6) and including a semi-transmissive reflective film (3) adapted to reflect the ligth emitting from a laser source (10) and to transmit the light returned from a record medium (7) of a disk (12), characterized in that the refractive index of said optical member (4) is set so as to be larger than the refractive index of said adhesive (6).
Inventors
- 👤 Hidehiro C/O Sony Corporation Kume
- 👤 Yoshiyuki C/O Sony Corporation Matsumoto
- 👤 You C/O Sony Corporation Yoshitoshi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 14:51
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/135; G11B7/1365; G11B7/1381; G11B7/08; G11B7/09; G11B7/094; G11B7/1356; G11B7/0908; G11B7/0912
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
146 words
An optical pickup head which reads information recorded to a record medium (12) thereof by irradiating said record medium (12) with a light generated from a laser source (10) and receiving a return light therefrom by a light sensor, characterized by a substrate (1) on which the optical sensor (2) is formed; the laser source (10; and an optical member (4) adhered by an adhesive (6) on said optical sensor (2) on said substrate (1) and including a semitransmissive reflective film (3) adapted to reflect the light emitting from the laser source (10) and to transmit the light returned from the record medium (12), and characterized in that an unnecessary light directly entered from the laser source (10) into the optical sensor (2) on the substrate (1) is eliminated by differentiating the refractive index of said optical member (4) from the refractive index of said adhesive.
Claim 2
Dependent Claim
146 words
An optical pickup head which reads information recorded to a record medium (12) thereof by irradiating said record medium (12) with a light generated from a laser source (10) and receiving a return light therefrom by a light sensor, characterized by a substrate (1) on which the optical sensor (2) is formed; the laser source (10; and an optical member (4) adhered by an adhesive (6) on said optical sensor (2) on said substrate (1) and including a semitransmissive reflective film (3) adapted to reflect the light emitting from the laser source (10) and to transmit the light returned from the record medium (12), and characterized in that an unnecessary light directly entered from the laser source (10) into the optical sensor (2) on the substrate (1) is eliminated by differentiating the refractive index of said optical member (4) from the refractive index of said adhesive.
Claim 3
Dependent Claim
80 words
An optical pickup head according to claim 1, characterized in that the refractive index n1 of said optical member (4) and the refractive index n2 of said adhesive (6) is set such that a critical angle α (=sin⁻¹ n2/n1) calculated by the refractive indices n1, n2 of the optical member (4) and the adhesive (6) are smaller than an incident angle of the light introduced into the optical member (4) from the laser source (10) forwarding the optical sensor (2).
Claim 4
Dependent Claim
36 words
An optical pickup head according to claim 1 or 2, characterized in that the refractive index of said optical member (4) is set so as to be larger than the refractive index of said adhesive (6).
Claim 5
Dependent Claim
27 words
An optical pickup head according to any one of claims 1 to 3, characterized in that said optical member (4) is made of an optical glass material.
Claim 6
Dependent Claim
23 words
An optical pickup head according to any one of claims 1 to 4, characterized in that said adhesive (6) is a resin adhesive.
References Cited (Backward Citations)
No citation records indexed.
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