US5715347A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High efficiency prism light guide with confocal parabolic cross section
Assignee: University of British Columbia
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Filing: 1995-10-12
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Granted: 1998-02-03
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Expires: 2015-10-12
Abstract
Abstract A hollow light guide with opposed first and second parallel sections having confocal, parabolic cross-sectional shape. The light guide may be a prism light guide, or other hollow light guide such as a metallic mirror light guide or a multi-layer dielectric light guide. The cross-sectional shapes have vertices separated by a distance which does not exceed about three times (preferably, about 2.5 times) the focal length of the shapes.
Inventors
- 👤 Lorne A. Whitehead
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:35
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/032; Y; Y10; Y10S; Y10S385/00; Y10S385/901
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
41 words
A hollow light guide comprising opposed first and second parallel sections, said sections having substantially confocal, substantially parabolic cross-sectional shape overlappingly enclosing a light guiding region, said shape having substantially constant cross-sectional area in any plane transverse to said parallel sections.
Claim 2
Dependent Claim
41 words
A hollow light guide comprising opposed first and second parallel sections, said sections having substantially confocal, substantially parabolic cross-sectional shape overlappingly enclosing a light guiding region, said shape having substantially constant cross-sectional area in any plane transverse to said parallel sections.
Claim 3
Dependent Claim
17 words
A light guide as defined in claim 1, wherein said light guide is a prism light guide.
Claim 4
Dependent Claim
31 words
A light guide as defined in claim 2, wherein said cross-sectional shapes have vertices separated by a distance which does not exceed about three times the focal length of said shapes.
Claim 5
Dependent Claim
21 words
A light guide as defined in claim 3, wherein said first and second sections are joined along one or more seams.
Claim 6
Dependent Claim
31 words
A light guide as defined in claim 2, wherein said cross-sectional shapes have vertices separated by a distance which does not exceed about 2.5 times the focal length of said shapes.
Claim 7
Dependent Claim
21 words
A light guide as defined in claim 5, wherein said first and second sections are joined along one or more seams.
Claim 8
Dependent Claim
21 words
A light guide as defined in claim 2, wherein said first and second sections are joined along one or more seams.
Claim 9
Independent Claim
79 words
A method of making a hollow light guide, said method comprising the steps of: (a) forming light guide wall material into first and second light guide sections, each of said sections having substantially parabolic cross-sectional shape, said shape having substantially constant cross-sectional area in any plane transverse to said sections; and, (b) joining said first and second light guide sections together to overlappingly enclose a light guiding region while maintaining said parabolic cross-sectional shapes substantially confocal with one another.
Claim 10
Independent Claim
79 words
A method of making a hollow light guide, said method comprising the steps of: (a) forming light guide wall material into first and second light guide sections, each of said sections having substantially parabolic cross-sectional shape, said shape having substantially constant cross-sectional area in any plane transverse to said sections; and, (b) joining said first and second light guide sections together to overlappingly enclose a light guiding region while maintaining said parabolic cross-sectional shapes substantially confocal with one another.
Claim 11
Dependent Claim
36 words
A method as defined in claim 8, further comprising, during said joining step, maintaining between parabolic vertices of said shapes a separation distance which does not exceed about three times the focal length of said shapes.
Claim 12
Dependent Claim
24 words
A method as defined in claim 9, wherein said light guide is a prism light guide and said wall material is prismatic wall material.
Claim 13
Dependent Claim
36 words
A method as defined in claim 8, further comprising, during said joining step, maintaining between parabolic vertices of said shapes a separation distance which does not exceed about 2.5 times the focal length of said shapes.
Claim 14
Dependent Claim
24 words
A method as defined in claim 11, wherein said light guide is a prism light guide and said wall material is prismatic wall material.
Claim 15
Dependent Claim
24 words
A method as defined in claim 8, wherein said light guide is a prism light guide and said wall material is prismatic wall material.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-02-02 | 2001-08-04 | 2002-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-02-02 | 2005-08-04 | 2006-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-02-02 | 2009-08-04 | 2010-02-03 | $7700.00 | Window Closed / Lapsed |