US4349249A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compound lens
Assignee: United States Department of Energy
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Filing: 1980-05-21
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Granted: 1982-09-14
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Expires: 2000-05-21
Abstract
Abstract The disclosure relates to at least one calcium fluoride optical element used in combination with at least two ordinary crown glass lens elements to greatly reduce secondary spectrum in optical systems.
Inventors
- 👤 Berlyn B. Brixner
- 👤 Morris M. Klein
- 👤 Max A. Winkler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:46
CPC Classifications
G; G02; G02B; G02B13/00; G02B1/00; G02B1/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
63 words
A compound lens comprising: at least one optical element comprising calcium fluoride; at least two optical elements comprising ordinary crown glass having an index of refraction with sodium light between about 1.500 and about 1.540 and an Abbe number of between about 56.5 and about 61.0; and wherein the secondary spectrum is less than about 1 part in 50,000 in the C-F range.
Claim 2
Dependent Claim
63 words
A compound lens comprising: at least one optical element comprising calcium fluoride; at least two optical elements comprising ordinary crown glass having an index of refraction with sodium light between about 1.500 and about 1.540 and an Abbe number of between about 56.5 and about 61.0; and wherein the secondary spectrum is less than about 1 part in 50,000 in the C-F range.
Claim 3
Dependent Claim
21 words
The invention of claim 1 wherein said ordinary crown glass has an index of refraction between about 1.515 and about 1.525.
Claim 4
Dependent Claim
21 words
The invention of claim 1 wherein said ordinary crown glass has an Abbe number of between about 58.5 and about 60.5.
Claim 5
Dependent Claim
31 words
The invention of claim 1 wherein said ordinary crown glass has an index of refraction between about 1.515 and about 1.525 and an Abbe number between about 58.5 and about 60.5.
Claim 6
Dependent Claim
21 words
The invention of claim 1 wherein said ordinary crown glass is selected from the group consisting of 518590, 522595 and 518603.
Claim 7
Dependent Claim
25 words
The invention of claim 1 wherein said optical elements are positioned to provide for said lens a field of view of less than about 12°.
Claim 8
Dependent Claim
25 words
The invention of claim 1 wherein said optical elements are positioned to provide for said lens a field of view of less than about 10°.
Claim 9
Dependent Claim
25 words
The invention of claim 1 wherein said optical elements are positioned to provide for said lens a field of view of less than about 7°.
Claim 10
Dependent Claim
23 words
The invention of claim 1 wherein said optical elements are positioned to provide an F/number for said lens between about F/5 and F/64.
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) | 1985-09-13 | 1986-03-15 | 1986-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-13 | 1990-03-15 | 1990-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-13 | 1994-03-15 | 1994-09-14 | $7700.00 | Window Closed / Lapsed |