Patent US3554629A successfully refreshed from Google Patents.
US3554629A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adapter lens for minimizing chromatic aberration in the infrared range
Assignee: Pentax Corp
•
Filing: 1968-03-27
•
Granted: 1971-01-12
•
Expires: 1988-03-27
Abstract
Abstract AS ADAPTER LENS SYSTEM IS MOUNTED ON THE FRONT OF A PHOTOGRAPHIC OBJECT LENS HAVING A FOCAL LENGTH BETWEEN 135 MM. AND 300 MM. AND INCLUDES A FLUORITE LENS OF A FOCAL LENGTH BETWEEN 350 MM. AND 500 MM. AND A NEGATIVE LENS OF GREATER REFRACTIVE INDEX, THE ADAPTER LENS SYSTEM HAVING A FOCAL LENGTH OF INFINITY. THE ADAPTER LENS REDUCES CHROMATIC ABERRATION OF THE LENS SYSTEM IN THE INFRARED RANGE.
Inventors
- 👤 Yasuo Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 00:46
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/14
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-11 | 1974-07-13 | 1975-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-11 | 1978-07-13 | 1979-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-11 | 1982-07-13 | 1983-01-12 | $7700.00 | Window Closed / Lapsed |