Patent US3598477A successfully refreshed from Google Patents.
US3598477A
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Lens having one spheric and one aspheric surface
Assignee: GTE Sylvania Inc
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Filing: 1969-06-09
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Granted: 1971-08-10
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Expires: 1989-06-09
Abstract
Abstract An automobile headlight lamp having an elliptical reflector, a light source at one focus of the ellipse and an aperture at the other, with a lens in front of the aperture, the lens having one focus at the focus of the ellipse. The lens has one spheric and one aspheric surface, the latter conforming to a stated mathematical equation in order to reduce aberrations, including the chromatic.
Inventors
- 👤 Robert E Levin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:48
CPC Classifications
G; G02; G02B; G02B3/00; G02B3/02; G02B3/04; F; F21; F21S; F21S41/00; F21S41/20; F21S41/25; F21S41/255
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
168 words
A lens for projecting a beam of light from a real object substantially at one conjugate stigmatic point, the other stigmatic point being at infinity, said real object being at substantially the second focus of an ellipsoid having a light source substantially at its first focus, said lens having one spheric and one aspheric surface at opposite sides, the aspheric surface conforming to the equation where and where psi is given in parametric form as and where X is measured along the optical axis and Y is measured normal to said axis, with the origin of coordinates being taken on said axis at the apex of the spheric surface, E is the thickness of the lens along said axis, Mu is the index of refraction for the material of the lens, R is the radius of the spheric surface, D is the distance on said axis from the second focus of said ellipsoid to the apex of the spheric surface, and sigma and Alpha function as dummy variables.
Claim 2
Dependent Claim
168 words
A lens for projecting a beam of light from a real object substantially at one conjugate stigmatic point, the other stigmatic point being at infinity, said real object being at substantially the second focus of an ellipsoid having a light source substantially at its first focus, said lens having one spheric and one aspheric surface at opposite sides, the aspheric surface conforming to the equation where and where psi is given in parametric form as and where X is measured along the optical axis and Y is measured normal to said axis, with the origin of coordinates being taken on said axis at the apex of the spheric surface, E is the thickness of the lens along said axis, Mu is the index of refraction for the material of the lens, R is the radius of the spheric surface, D is the distance on said axis from the second focus of said ellipsoid to the apex of the spheric surface, and sigma and Alpha function as dummy variables.
Claim 3
Dependent Claim
14 words
The lens of claim 1, in which the material of the lens is glass.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-09 | 1975-02-08 | 1975-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-09 | 1979-02-08 | 1979-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-09 | 1983-02-08 | 1983-08-10 | $7700.00 | Window Closed / Lapsed |