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US3826751A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective optical filter and method of manufacture
Assignee: American Optical Corp
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Filing: 1972-08-15
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Granted: 1974-07-30
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Expires: 1992-08-15
Abstract
Abstract AN IMPROVED HIGH OPTICAL QUALITY, PLASTIC OPTICAL FILTER FOR RED AND NEAR INFRARED WAVELENGTHS HAS VERY LOW TRANSMITTANCE IN THE RED PORTION OF THE VISIBLE SPECTRUM, A REDUCED NEAR INFRARED TRANSMITTANCE, AND A HIGH ABRASION RESISTANCE. THE OPTICAL FILTER IS FORMED BY DISSOLVING A SUFFICIENT QUANTITY OF CUPRIC OR CUPROUS CHLORIDE IN A MIXTURE OF MONOPROPYLENE GLYCOL MONOMALEATE, AND ALLYL DIGLYCOL CARBONATE, MIXING THE SOLUTION WITH DIISOPROPYL PEROXYDICARBONATE INITIATOR, FILTERING THE RESULTANT MIXTURE, AND CASTING THE FILTERED MIXTURE.
Inventors
- 👤 N Laliberte
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:38
CPC Classifications
G; G02; G02C; G02C7/00; G02C7/10; G02C7/108
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) | 1977-07-29 | 1978-01-28 | 1978-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-29 | 1982-01-28 | 1982-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-29 | 1986-01-28 | 1986-07-30 | $7700.00 | Window Closed / Lapsed |