Patent US5358349A successfully refreshed from Google Patents.
EP0346844A2
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EP
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Optical head apparatus
Assignee: NEC Corp
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Filing: 1989-06-13
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Granted: —
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Expires: 2009-06-13
Abstract
Abstract In an optical head apparatus, a minute light beam spot is formed on a recording medium (6) by a focusing lens (5). The focusing lens focuses light radiated from a light source (1) to provide the minute light beam spot. Between the light source and the focusing lens, a light intensity or phase distribution converter (3) is provided, so that the minute light beam spot will be a super resolved light beam spot.
Inventors
- 👤 Yutaka C/O Nec Corporation Hirose
- 👤 Yutaka C/O Nec Corporation Yamanaka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 03:55
CPC Classifications
B; B82; B82Y; B82Y10/00; G; G11; G11B; G11B7/00; G11B7/004; G11B7/005; G11B7/12; G11B7/125; G11B7/128; G11B7/135; G11B7/1365; G11B7/1381
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
108 words
An optical head apparatus, comprising: a light focusing system for focusing light radiated from a light source on a recording medium to form a minute light beam spot on said recording medium by means of a focusing lens; an information reading-out system for reading-out information stored in said recording medium in accordance with the receiving of light reflected from said recording medium; and a light intensity distribution converter for reducing a light intensity of a central portion of said light radiated from said light source relatively to a light intensity of a peripheral portion of said radiated light in a cross-section of light incident to said focusing lens.
Claim 2
Dependent Claim
108 words
An optical head apparatus, comprising: a light focusing system for focusing light radiated from a light source on a recording medium to form a minute light beam spot on said recording medium by means of a focusing lens; an information reading-out system for reading-out information stored in said recording medium in accordance with the receiving of light reflected from said recording medium; and a light intensity distribution converter for reducing a light intensity of a central portion of said light radiated from said light source relatively to a light intensity of a peripheral portion of said radiated light in a cross-section of light incident to said focusing lens.
Claim 3
Dependent Claim
45 words
An optical head apparatus, according to claim 1: wherein said light intensity distribution converter, includes: a light shielding means for passing light in a central region of said cross-section and shielding light of adjacent regions on both sides of said central portion in said cross-section.
Claim 4
Dependent Claim
33 words
An optical head apparatus, according to claim 1 or 2, wherein said light intensity distribution converter, includes: a light dividing means for dividing said radiated light into plural and parallel light beam fluxes.
Claim 5
Dependent Claim
50 words
An optical head apparatus, according to any of claims 1 to 3, wherein said light intensity distribution converter, provides: a light intensity distribution in which a light amount is maximum at a peripheral portion of said focusing lens and is reduced towards a central portion of said focusing lens moderately.
Claim 6
Dependent Claim
58 words
An optical head apparatus, according to any of claims 1 to 4, wherein said information reading-out system, includes: a light focusing system for focusing said reflected light by means of a focusing lens; and a means selected from an aperture and a slit, said means being positioned at a focus of said focusing lens for said reflected light.
Claim 7
Dependent Claim
97 words
An optical head apparatus, comprising: a light focusing system for focusing light radiated from a light source on a recording medium to form a minute light beam spot on said recording medium by means of a focusing lens; an information reading-out system for reading- out information stored in said recording medium in accordance with the receiving of light reflected from said recording medium; and a light phase distribution converter for shifting a light phase of a central portion of said light radiated from said light source in a cross section of light incident to said focusing lens.
Claim 8
Dependent Claim
97 words
An optical head apparatus, comprising: a light focusing system for focusing light radiated from a light source on a recording medium to form a minute light beam spot on said recording medium by means of a focusing lens; an information reading-out system for reading- out information stored in said recording medium in accordance with the receiving of light reflected from said recording medium; and a light phase distribution converter for shifting a light phase of a central portion of said light radiated from said light source in a cross section of light incident to said focusing lens.
References Cited (Backward Citations)
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