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US3506342A
Expired / Lapsed
US
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Instrument for the measurement of visual acuity and the astigmatic axis
Assignee: United States Department of the Air Force
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Filing: 1967-10-05
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Granted: 1970-04-14
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Expires: 1987-10-05
Abstract
No abstract record available.
Inventors
- 👤 Robert E Van Patten
- 👤 Paul W Lappin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 06:44
CPC Classifications
A; A61; A61B; A61B3/00; A61B3/02; A61B3/028; A61B3/036
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1270830A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-04-13 | 1973-10-13 | 1974-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-04-13 | 1977-10-13 | 1978-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-04-13 | 1981-10-13 | 1982-04-14 | $7700.00 | Window Closed / Lapsed |