US2624240A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Infrared band pass filter
Assignee: Polaroid Corp
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Filing: 1949-03-10
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Granted: 1953-01-06
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Expires: 1969-03-10
Abstract
No abstract record available.
Inventors
- 👤 Elkan R Blout
- 👤 Richard S Corley
- 👤 Patricia L Snow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:09
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/22; G02B5/223; G02B5/206; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/256
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
142 words
A NARROW BAND PASS FILTER SHOWING RELATIVELY HIGH TRANSMISSION TO INFRARED RADIATION IN THE WAVE BAND BETWEEN 3.5 AND 5.5 MICRONS AND COMPRISING A SHEET COMPRISING PARTIALLY DEHYDROHALOGENATED MATERIAL FROM THE CLASS CONSISTING OF POLYVINYL CHLORIDE AND POLYVINYLIDENE CHLORIDE WHICH HAS BEEN IMBIBED IN A BATH COMPRISING A SWELLING AGENT, A CONVERSION AGENT AND A DILUENT AND THEREAFTER HEATED UNTIL THE CHLORINE CONTENT OF SAID SHEET HAS BEEN REDUCED BY FROM ONE-FIFTH TO ONE-THIRD, AND A HIGHLY CONCENTARATED, THIN COATING ON SAID SHEET OF A MULTIPLICITY OF MINUTE PARTICLES OF A METALLIC OXIDE OF MEANS LINEAR PARTICLE SIZE BETWEEN .25 AND .5 MICRON, SAID FILTER BEING SUBSTANTIALLY OPAQUE TO ALL RADIATION IN THE VISIBLE AND IN THE NEAR-INFRARED BELOW ABOUT 1 MICRON AND SHOWING VARY LOW TRANSMISSION, OF THE ORDER OF NOT MORE THAN 5%, FOR RADIATION BETWEEN 1 AND 3.5 MICRONS.
Claim 2
Dependent Claim
142 words
A NARROW BAND PASS FILTER SHOWING RELATIVELY HIGH TRANSMISSION TO INFRARED RADIATION IN THE WAVE BAND BETWEEN 3.5 AND 5.5 MICRONS AND COMPRISING A SHEET COMPRISING PARTIALLY DEHYDROHALOGENATED MATERIAL FROM THE CLASS CONSISTING OF POLYVINYL CHLORIDE AND POLYVINYLIDENE CHLORIDE WHICH HAS BEEN IMBIBED IN A BATH COMPRISING A SWELLING AGENT, A CONVERSION AGENT AND A DILUENT AND THEREAFTER HEATED UNTIL THE CHLORINE CONTENT OF SAID SHEET HAS BEEN REDUCED BY FROM ONE-FIFTH TO ONE-THIRD, AND A HIGHLY CONCENTARATED, THIN COATING ON SAID SHEET OF A MULTIPLICITY OF MINUTE PARTICLES OF A METALLIC OXIDE OF MEANS LINEAR PARTICLE SIZE BETWEEN .25 AND .5 MICRON, SAID FILTER BEING SUBSTANTIALLY OPAQUE TO ALL RADIATION IN THE VISIBLE AND IN THE NEAR-INFRARED BELOW ABOUT 1 MICRON AND SHOWING VARY LOW TRANSMISSION, OF THE ORDER OF NOT MORE THAN 5%, FOR RADIATION BETWEEN 1 AND 3.5 MICRONS.
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) | 1956-01-06 | 1956-07-07 | 1957-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-01-06 | 1960-07-07 | 1961-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-01-06 | 1964-07-07 | 1965-01-06 | $7700.00 | Window Closed / Lapsed |