US3659922A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Symmetrical half-lens optical system
Assignee: Xerox Corp
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Filing: 1971-02-25
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Granted: 1972-05-02
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Expires: 1991-02-25
Abstract
Abstract A two component Split-Dagor type lens is herein disclosed utilizing a reflecting surface at the stop position to reverse the light rays passing through the system thus simulating a conventional symmetrical Split-Dagor system.
Inventors
- 👤 George L Mccrobie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:16
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
106 words
An optical objective including a first component comprised of a positive element and a negative element in contiguous release joined to form a doublet and a second component positive element separated from the negative element by an air gap and a reflecting surface position on the other side of said negative element at the stop position constructed substantially according to the following specifications: E.F.L. 7.47 f/4.5 - f/11.0 Lens Radii Thickness Spaces Nd Vd R1 2.145 S1 13.280 I t1 0.687 1.613 58.6 -R2 11.606 II t2 - 0.253 1.541 47.2 R3 1.524 S2 0.114 R4 2.273 III t3 0.289 1.541 47.2 R5 3.641 S3 0.306
Claim 2
Dependent Claim
106 words
An optical objective including a first component comprised of a positive element and a negative element in contiguous release joined to form a doublet and a second component positive element separated from the negative element by an air gap and a reflecting surface position on the other side of said negative element at the stop position constructed substantially according to the following specifications: E.F.L. 7.47 f/4.5 - f/11.0 Lens Radii Thickness Spaces Nd Vd R1 2.145 S1 13.280 I t1 0.687 1.613 58.6 -R2 11.606 II t2 - 0.253 1.541 47.2 R3 1.524 S2 0.114 R4 2.273 III t3 0.289 1.541 47.2 R5 3.641 S3 0.306
References Cited (Backward Citations)
GB1008952A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-02 | 1975-11-01 | 1976-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-02 | 1979-11-01 | 1980-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-02 | 1983-11-01 | 1984-05-02 | $7700.00 | Window Closed / Lapsed |