US3561840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Projection screen
Assignee: Hitachi Ltd
•
Filing: 1968-06-03
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Granted: 1971-02-09
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Expires: 1988-06-03
Abstract
Abstract PARALLEL TRANSPARENT RODS ARE BONDED TO EACH OTHER AND TO A TRANSPARENT FILM. THE FILM''S OTHER SIDE IS BONDED TO A DIFFUSED REFLECTION SHEET BUT IS SEPARATED BY A MICROSCOPIC AIR GAP. PASTE DOT BETWEEN THE FILM AND THE REFLECTING SHEET PROVIDE THE GAP.
Inventors
- 👤 Takeo Seki
- 👤 Masuo Fukumura
- 👤 Hajime Fukke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:01
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/12; G02B5/126; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/60; G03B21/602
Claims Analysis
Total Claims: 0
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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) | 1974-02-08 | 1974-08-10 | 1975-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-08 | 1978-08-10 | 1979-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-08 | 1982-08-10 | 1983-02-09 | $7700.00 | Window Closed / Lapsed |