Patent US3501224A successfully refreshed from Google Patents.
US3501224A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zoom lens having four lens groups
Assignee: Pentax Corp
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Filing: 1967-01-24
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Granted: 1970-03-17
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Expires: 1987-01-24
Abstract
No abstract record available.
Inventors
- 👤 Yasuo Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:22
CPC Classifications
G; G02; G02B; G02B15/00; G02B15/14; G02B15/144; G02B15/1441
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
18 words
15<F1/F6<0.65 N10-N11 <0.1 0.12< R16 / F3 <0.2 N9>1.62 0.2< R21 / F4 <0.3 N12>1.62 0.45>R7/F F1 >0.28
References Cited (Backward Citations)
GB975309A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-03-16 | 1973-09-15 | 1974-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-03-16 | 1977-09-15 | 1978-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-03-16 | 1981-09-15 | 1982-03-17 | $7700.00 | Window Closed / Lapsed |