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US3255665A
Expired / Lapsed
US
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Article of manufacture for controlling light transmittance
Assignee: 3M Co
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Filing: 1964-05-21
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Granted: 1966-06-14
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Expires: 1984-05-21
Abstract
No abstract record available.
Inventors
- 👤 Richard L Weiher
- 👤 William C Tait
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:55
CPC Classifications
F; F21; F21S; F21S11/00; F21V; F21V13/00; F21V13/02; F21V13/04; F21V5/00; F21V5/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
155 words
A SHEET MATERIAL FOR CONTROLLING LIGHT TRANSMITTANCE COMPRISING A LAYER OF LIGHT TRANSMITTING SUBSTANCE HAVING A FLAT SURFACE ON ONE SIDE AND A SERIES OF ALTERNATING FIRST AND SECOND PRISM FACES ON THE OTHER SIDE, A MEDIUM ADJACENT SAID FIRST PRISM FACES HAVING AN INDEX OF REFRACTION LESS THAN THE INDEX OF REFRACTION OF SAID SUBSTANCE, SAID FIRST PRISM FACES AT AN ANLGE TO THE FLAT SURFACE EQUAL TO THE DIFFERENCE BETWEEN THE CRITICAL ANGLE OF INCIDENCE AT THE FIRST PRISM FACES AND THE ANGLE OF REFRACTION AT SAID FLAT SURFACE OF A RAY STRIKING SAID SHEET MATERIAL AT A PREDETERMINED ANGLE OF INCIDENCE BEYOND WHICH IT IS DESIRED TO PREVENT LIGHT RAYS FROM PASSING THROUGH THE SHEET MATERIAL AND SAID SECOND PRISM FACES COMPRISING MEANS THAT REPELS SUBSTANTIALLY ALL OF SAID LIGHT RAYS UPON THEIR STRIKING SAID SECOND PRISM FACES AND TO CAUSE SAID REPELLED RAYS TO LEAVE SAID LAYER THROUGH SAID FLAT SURFACE.
Claim 2
Dependent Claim
155 words
A SHEET MATERIAL FOR CONTROLLING LIGHT TRANSMITTANCE COMPRISING A LAYER OF LIGHT TRANSMITTING SUBSTANCE HAVING A FLAT SURFACE ON ONE SIDE AND A SERIES OF ALTERNATING FIRST AND SECOND PRISM FACES ON THE OTHER SIDE, A MEDIUM ADJACENT SAID FIRST PRISM FACES HAVING AN INDEX OF REFRACTION LESS THAN THE INDEX OF REFRACTION OF SAID SUBSTANCE, SAID FIRST PRISM FACES AT AN ANLGE TO THE FLAT SURFACE EQUAL TO THE DIFFERENCE BETWEEN THE CRITICAL ANGLE OF INCIDENCE AT THE FIRST PRISM FACES AND THE ANGLE OF REFRACTION AT SAID FLAT SURFACE OF A RAY STRIKING SAID SHEET MATERIAL AT A PREDETERMINED ANGLE OF INCIDENCE BEYOND WHICH IT IS DESIRED TO PREVENT LIGHT RAYS FROM PASSING THROUGH THE SHEET MATERIAL AND SAID SECOND PRISM FACES COMPRISING MEANS THAT REPELS SUBSTANTIALLY ALL OF SAID LIGHT RAYS UPON THEIR STRIKING SAID SECOND PRISM FACES AND TO CAUSE SAID REPELLED RAYS TO LEAVE SAID LAYER THROUGH SAID FLAT SURFACE.
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) | 1969-06-13 | 1969-12-13 | 1970-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-06-13 | 1973-12-13 | 1974-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-06-13 | 1977-12-13 | 1978-06-14 | $7700.00 | Window Closed / Lapsed |