US2728731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making electroluminescent phosphors
Assignee: GTE Sylvania Inc
•
Filing: 1952-09-09
•
Granted: 1955-12-27
•
Expires: 1972-09-09
Abstract
No abstract record available.
Inventors
- 👤 Keith H Butler
- 👤 Alden B Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:39
CPC Classifications
H; H05; H05B; H05B33/00; H05B33/12; H05B33/14; H05B33/145
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
85 words
THE METHOD OF MAKING AN ELECTROLUMINESCENT PHOSPHOR CONTAINING A SMALL AMOUNT OF LEAD, WHICH METHOD COMPRISES MIXING WITH ACTIVATING COMPOUNDS OF COPPER AND LEAD A SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF ZINC SULFIDE, CADMIUM SULFIDE, ZINC SELENIDE, CADMIUM SELENIDE, FIRING THE RESULTANT MIXTURE IN THE TEMPERATURE RANGE BETWEEN 1200*F. AND 1800*F., RESTRICTING THE VENTILATION DURING FIRING SUFFICIENTLY TO FORM A BLACK SURFACE LAYER FROM THE FIRED MIXTURE, REMOVING SAID BLACK SURFACE LAYER, AND THEN REMOVING THE REMAINDER OF THE FIRED MIXTURE FROM THE CRUCIBLE.
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) | 1958-12-26 | 1959-06-27 | 1959-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-12-26 | 1963-06-27 | 1963-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-12-26 | 1967-06-27 | 1967-12-27 | $7700.00 | Window Closed / Lapsed |