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Patent US3538503A successfully refreshed from Google Patents.
US3538503A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic information retrieval system
Assignee: Japan Science and Technology Agency
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Filing: 1967-09-14
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Granted: 1970-11-03
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Expires: 1987-09-14
Abstract
No abstract record available.
Inventors
- 👤 Takuji Jitsukawa
- 👤 Yasuo Ikeda
- 👤 Yoshiharu Harada
- 👤 Yasunori Murayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:34
CPC Classifications
G; G11; G11B; G11B27/00; G11B27/10; G11B27/102; G11B27/107
Claims Analysis
Total Claims: 0
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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) | 1973-11-02 | 1974-05-04 | 1974-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-02 | 1978-05-04 | 1978-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-02 | 1982-05-04 | 1982-11-03 | $7700.00 | Window Closed / Lapsed |