Patent US3357775A successfully refreshed from Google Patents.
US3357775A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Projection objective affording variable magnification
Assignee: 3M Co
•
Filing: 1965-10-24
•
Granted: 1967-12-12
•
Expires: 1985-10-24
Abstract
No abstract record available.
Inventors
- 👤 Roger H Appeldorn
- 👤 David C Gilkeson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:10
CPC Classifications
G; G02; G02B; G02B15/00; G02B15/14; G02B15/145; G02B15/1451; G02B15/145113; G02B15/143
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
143 words
A LENS SYSTEM COMPRISING SIX AIR SPACED LENS ELEMENTS, ONE OF SAID ELEMENTS BEING A TRIANGULAR PRISM INTEGRATED IN SAID SYSTEM AND POSITIONED BETWEEN OTHER OF SAID ELEMENTS FOR CHANGING THE DIRECTION OF THE OPTIC AXIS OF THE LENS SYSTEM, THE OTHER FIVE OF SAID ELEMENTS BEING OPTICALLY ALIGNED ALONG SAID OPTIC AXIS FROM FRONT TO REAR, THE FIRST OF SAID FIVE ELEMENTS BEING A POSITIVE LENS, THE SECOND BEING A NEGATIVE LENS POSITIONED ADJACENT SAID FIRST ELEMENT AND ADJACENT ONE SIDE OF THE PRISM, THE THIRD BEING A POSITIVE LENS POSITIONED ADJACENT ANOTHER SIDE OF SAID PRISM, THE FOURTH BEING A POSITIVE LENS, THE FIFTH BEING A NEGATIVE LENS, AND SAID FIRST AND FIFTH OF SAID OTHER FIVE ELEMENTS BEING MOVABLE ALONG THE OPTIC AXIS FOR CHANGING THE MAGNIFICATION VALUE AND THE EQUIVALENT FOCAL LENGTH OF THE LENS SYSTEM AND FOR FOCUSING.
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) | 1970-12-11 | 1971-06-12 | 1971-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-12-11 | 1975-06-12 | 1975-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-12-11 | 1979-06-12 | 1979-12-12 | $7700.00 | Window Closed / Lapsed |