US3572903A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spherically corrected fresnel lenses
Assignee: Jenoptik AG
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Filing: 1969-06-06
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Granted: 1971-03-30
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Expires: 1989-06-06
Abstract
Abstract The optically effective face of a Fresnel lens is so shaped that two separate points in its optical axis are imaged without spherical aberration. Said face carries the Fresnel echelons. If there are echelons on both sides of the Fresnel lens, both echelon carrying faces have a form which is defined by an equation.
Inventors
- 👤 Christian Hofmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:25
CPC Classifications
G; G02; G02B; G02B3/00; G02B3/02; G02B3/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
45 words
A Fresnel lens for producing an aberrationless image of any two points of its optical axis, comprising two optically active faces and a Fresnel system at each of said faces, the meridional section of each of said faces having a form defined by the equation
Claim 2
Dependent Claim
45 words
A Fresnel lens for producing an aberrationless image of any two points of its optical axis, comprising two optically active faces and a Fresnel system at each of said faces, the meridional section of each of said faces having a form defined by the equation
References Cited (Backward Citations)
GB660352A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-29 | 1974-09-28 | 1975-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-29 | 1978-09-28 | 1979-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-29 | 1982-09-28 | 1983-03-30 | $7700.00 | Window Closed / Lapsed |