US3220814A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of treating quartz for optical use
Assignee: US Philips Corp
•
Filing: 1961-04-14
•
Granted: 1965-11-30
•
Expires: 1981-04-14
Abstract
No abstract record available.
Inventors
- 👤 Haven Ijsbrand
- 👤 Kats Adriaan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:16
CPC Classifications
C; C03; C03C; C03C23/00; C03C23/007
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
40 words
A METHOD OF TREATING QUARTZ TO REDUCE ABSORPTIONS OF INFRA-RED RADIATION UP TO 3 1/2 U COMPRISING HEATING THE QUARTZ BETWEEN ABOUT 900*C. AND 1200*C. IN AN ATMOSPHERE CONTAINING CARBON MONOXIDE FOR ABOUT 24 HOURS FOR EACH MILLIMETER OF THICKNESS.
Claim 2
Independent Claim
40 words
A METHOD OF TREATING QUARTZ TO REDUCE ABSORPTIONS OF INFRA-RED RADIATION UP TO 3 1/2 U COMPRISING HEATING THE QUARTZ BETWEEN ABOUT 900*C. AND 1200*C. IN AN ATMOSPHERE CONTAINING CARBON MONOXIDE FOR ABOUT 24 HOURS FOR EACH MILLIMETER OF THICKNESS.
References Cited (Backward Citations)
US2612726A
Cited
US2897126A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-11-29 | 1969-05-31 | 1969-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-29 | 1973-05-31 | 1973-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-29 | 1977-05-31 | 1977-11-30 | $7700.00 | Window Closed / Lapsed |