US5029975A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Despeckling screen utilizing optical fibers and method of reducing interference using same
Assignee: Mitre Corp
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Filing: 1990-01-24
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Granted: 1991-07-09
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Expires: 2010-01-24
Abstract
Abstract The invention comprises a method and apparatus for decohering coherent light projected onto a screen by transmitting the coherent light through a series of light conducting optical fibers, preferably of varying length.
Inventors
- 👤 Richard W. Pease
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:20
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/48
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
97 words
Means for altering the coherent properties of light emitted from a laser along a first direction comprising; a multiplicity of light conducting, optical fibers arranged in a mutually parallel array with said fibers oriented to receive light at a first end from said laser and to emit light conducted by said fibers from a second end, said fibers having a high fiber length to fiber width ratio and lengths that vary, thereby inducing phase differences between the light emitted from the said second ends of different ones of said fibers thereby avoiding the creation of interference patterns.
Claim 2
Dependent Claim
97 words
Means for altering the coherent properties of light emitted from a laser along a first direction comprising; a multiplicity of light conducting, optical fibers arranged in a mutually parallel array with said fibers oriented to receive light at a first end from said laser and to emit light conducted by said fibers from a second end, said fibers having a high fiber length to fiber width ratio and lengths that vary, thereby inducing phase differences between the light emitted from the said second ends of different ones of said fibers thereby avoiding the creation of interference patterns.
Claim 3
Dependent Claim
33 words
The apparatus of claim 1 wherein said first ends of said fibers are positioned perpendicular to and directly against the surface of a light transmitting substrate oriented generally traverse to said first direction.
Claim 4
Dependent Claim
17 words
The apparatus of claim 1 wherein said fiber length to fiber width ratio is at least 40:1.
Claim 5
Dependent Claim
16 words
The apparatus of claim 1 wherein said fibers have a diameter of less than 0.1 mm.
Claim 6
Dependent Claim
18 words
The apparatus of claim 1 wherein the length of said fibers ranges from 5 mm. to 10 mm.
Claim 7
Dependent Claim
20 words
The apparatus of claim 1 wherein the length of said fibers varies randomly within a range not more than 15%.
Claim 8
Dependent Claim
12 words
The apparatus of claim 1 wherein said fibers are made of plastic.
Claim 9
Dependent Claim
48 words
The apparatus of claim 1 wherein the ends of said fibers are neither optically smooth nor not optically rough, thereby allowing moderate dispersion of light as it enters said first end of said fibers and moderate diffusion of light as it exits said second end of said fibers.
Claim 10
Dependent Claim
17 words
The apparatus of claim 2 wherein said substrate is comprised of a transparent material having flat surfaces.
Claim 11
Dependent Claim
13 words
The apparatus of claim 9 wherein said substrate means is made of plexiglass.
Claim 12
Independent Claim
70 words
A method of reducing interference or speckle patterns caused by the diffusion of coherent light onto a screen by altering the coherent properties of said light at the screen surface, said method comprising the steps of transmitting said coherent light through a multiplicity of light conducting optical fibers, said fibers lying adjacent to and parallel with each other, having a high length to width ratio, and having lengths that vary.
Claim 13
Independent Claim
70 words
A method of reducing interference or speckle patterns caused by the diffusion of coherent light onto a screen by altering the coherent properties of said light at the screen surface, said method comprising the steps of transmitting said coherent light through a multiplicity of light conducting optical fibers, said fibers lying adjacent to and parallel with each other, having a high length to width ratio, and having lengths that vary.
Claim 14
Dependent Claim
41 words
The method of claim 11 wherein prior to transmitting said coherent light through said multiplicity of light conducting optical fibers, said coherent light is dispersed on a piece of transparent substrate which is optically coupled to said multiplicity of optical fibers.
Claim 15
Independent Claim
86 words
A method of reducing interference or speckle patterns caused by the diffusion of coherent light onto a screen by altering the coherent properties of said light at the screen surface, said method comprising the steps of projecting said coherent light onto a piece of transparent substrate, and transmitting said coherent light through a multiplicity of light-conducting optical fibers, said fibers lying adjacent to and parallel with one another optically coupled to said transparent substrate, having a high length to width ratio, and having lengths that vary.
Claim 16
Independent Claim
86 words
A method of reducing interference or speckle patterns caused by the diffusion of coherent light onto a screen by altering the coherent properties of said light at the screen surface, said method comprising the steps of projecting said coherent light onto a piece of transparent substrate, and transmitting said coherent light through a multiplicity of light-conducting optical fibers, said fibers lying adjacent to and parallel with one another optically coupled to said transparent substrate, having a high length to width ratio, and having lengths that vary.
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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) | 1994-07-08 | 1995-01-07 | 1995-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-08 | 1999-01-07 | 1999-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-08 | 2003-01-07 | 2003-07-09 | $7700.00 | Window Closed / Lapsed |