Patent US3205774A successfully refreshed from Google Patents.
US3205774A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermally compensated plastic triplet lens
Assignee: Eastman Kodak Co
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Filing: 1961-07-24
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Granted: 1965-09-14
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Expires: 1981-07-24
Abstract
No abstract record available.
Inventors
- 👤 Cameron B Estes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:00
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/02; G02B7/028; G02B13/00; G02B7/022
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
123 words
A THERMALLY COMPENSATED OBJECTIVE COMPRISING TWO POSITIVE LENS ELEMENTS OF POLYMETHYLMETHYLMETHACRYLATE AXIALLY ALIGNED AND SPACED ON OPPOSITE SIDES OF A NEGATIVE LENS ELEMENT OF ACRYLONITRILE-STYRENE COPOLYMER, THE FOCAL LENGTH MEASURED FROM THE OUTER REAR SURFACE OF THE REAR POSITIVE ELEMENT BEING SUBSTANTIALLY INDEPENDENT OF CHANGES IN TEMPERATURE, MEANS FOR SUPPORTING THE NEGATIVE ELEMENT SPACED FROM THE REAR POSITIVE ELEMENT BY A MEMBER MADE OF POLYMETHYLMETHACRYLATE AND MEANS FOR SUPPORTING THE FRONT POSITIVE ELEMENT SPACED FROM THE REAR POSITIVE ELEMENT BY A SPACER OF A MATERIAL HAVING A THERMAL COEFFICIENT OF LINEAR EXPANSION IN THE RANGE 15X10**-5/*C. TO 30X10**-5/*C., THE AXIAL LENGTH OF SAID SPACER BEING GREATER THAN ONCE, AND LESS THAN TWICE, THE AXIAL DISTANCE BETWEEN THE CENTERS OF THE TWO POSITIVE ELEMENTS.
Claim 2
Dependent Claim
123 words
A THERMALLY COMPENSATED OBJECTIVE COMPRISING TWO POSITIVE LENS ELEMENTS OF POLYMETHYLMETHYLMETHACRYLATE AXIALLY ALIGNED AND SPACED ON OPPOSITE SIDES OF A NEGATIVE LENS ELEMENT OF ACRYLONITRILE-STYRENE COPOLYMER, THE FOCAL LENGTH MEASURED FROM THE OUTER REAR SURFACE OF THE REAR POSITIVE ELEMENT BEING SUBSTANTIALLY INDEPENDENT OF CHANGES IN TEMPERATURE, MEANS FOR SUPPORTING THE NEGATIVE ELEMENT SPACED FROM THE REAR POSITIVE ELEMENT BY A MEMBER MADE OF POLYMETHYLMETHACRYLATE AND MEANS FOR SUPPORTING THE FRONT POSITIVE ELEMENT SPACED FROM THE REAR POSITIVE ELEMENT BY A SPACER OF A MATERIAL HAVING A THERMAL COEFFICIENT OF LINEAR EXPANSION IN THE RANGE 15X10**-5/*C. TO 30X10**-5/*C., THE AXIAL LENGTH OF SAID SPACER BEING GREATER THAN ONCE, AND LESS THAN TWICE, THE AXIAL DISTANCE BETWEEN THE CENTERS OF THE TWO POSITIVE ELEMENTS.
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) | 1968-09-13 | 1969-03-15 | 1969-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-09-13 | 1973-03-15 | 1973-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-09-13 | 1977-03-15 | 1977-09-14 | $7700.00 | Window Closed / Lapsed |