Patent US3621231A successfully refreshed from Google Patents.
US3621231A
Expired / Lapsed
US
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Antiglare light box
Assignee: Individual
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Filing: 1969-03-10
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Granted: 1971-11-16
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Expires: 1989-03-10
Abstract
Abstract An antiglare light box is provided having a pair of right angularly disposed linear polarizers arranged in spaced relation over the lights of the light box. The material being viewed is positioned between the linear polarizers and printed on a base which either possesses optical activity such that it will rotate the planes of polarization of the lowermost polarizer 90* so that the light will then pass through the second polarizer, or is a depolarizer and depolarizes the light from the first polarizing screen so that it can pass through the second polarizing screen.
Inventors
- 👤 Dwin R Craig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:37
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/28; G02B27/281
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
183 words
An antiglare light box comprising a receptacle having an source of illumination therein; a linear-polarizing filter overlying an open top of said receptacle with light from said source of illumination being adapted to pass therethrough; a second linear-polarizing filter arranged in vertically space generally parallel relation to said first filter with the plane of polarization of said second filter extending perpendicularly to the plane of polarization of said first filter; and nonpolarizing means positioned between said first and said second filters for altering at least a portion of the light passing through said first filter to enable it to pass through said second filter; said last named means being either 1. a transparent optically active film having the property of rotating by 90* the plane of polarization of polarized light passing thErethrough, or 2. paper having the property of depolarizing polarized light passing therethrough, whereby light passing through said first polarizing filter then through said means passes through said second polarizing filter and light passing through said first polarizing filter but not passing through said means is intercepted by said second polarizing filter.
Claim 2
Dependent Claim
183 words
An antiglare light box comprising a receptacle having an source of illumination therein; a linear-polarizing filter overlying an open top of said receptacle with light from said source of illumination being adapted to pass therethrough; a second linear-polarizing filter arranged in vertically space generally parallel relation to said first filter with the plane of polarization of said second filter extending perpendicularly to the plane of polarization of said first filter; and nonpolarizing means positioned between said first and said second filters for altering at least a portion of the light passing through said first filter to enable it to pass through said second filter; said last named means being either 1. a transparent optically active film having the property of rotating by 90* the plane of polarization of polarized light passing thErethrough, or 2. paper having the property of depolarizing polarized light passing therethrough, whereby light passing through said first polarizing filter then through said means passes through said second polarizing filter and light passing through said first polarizing filter but not passing through said means is intercepted by said second polarizing filter.
Claim 3
Dependent Claim
49 words
paper having the property of depolarizing polarized light passing therethrough, whereby light passing through said first polarizing filter then through said means passes through said second polarizing filter and light passing through said first polarizing filter but not passing through said means is intercepted by said second polarizing filter.
Claim 4
Dependent Claim
49 words
paper having the property of depolarizing polarized light passing therethrough, whereby light passing through said first polarizing filter then through said means passes through said second polarizing filter and light passing through said first polarizing filter but not passing through said means is intercepted by said second polarizing filter.
Claim 5
Dependent Claim
16 words
A device as claimed in claim 1 wherein said optically active film is formed of polyester.
Claim 6
Dependent Claim
15 words
A device as claimed in claim 1 wherein the depolarizing filter is a tracing sheet.
References Cited (Backward Citations)
US3506333A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |