US5513533A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Detection of vibrational energy via optical interference patterns
Assignee: United States Department of the Navy
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Filing: 1993-04-15
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Granted: 1996-05-07
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Expires: 2013-04-15
Abstract
Abstract A method and apparatus for sensing and measuring vibrational energy in a structure subject to vibrations is described. The method comprises the steps of applying a thin transparent film material having a thickness to a structure subject to vibrations and measuring the vibrational energy within the structure by measuring changes in the thickness of the thin transparent film material resulting from vibrations within the structure being transmitted to the thin transparent film material. The apparatus for sensing and measuring the vibrational energy comprises a light source for generating a coherent light beam, the thin transparent film material, and a detector for receiving reflected light rays from the top and bottom surfaces of the film material.
Inventors
- 👤 Bradford A. Wheeler
- 👤 Antonio L. Deus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:43
CPC Classifications
G; G01; G01H; G01H9/00
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
64 words
A method for sensing and measuring vibrational energy in a structure comprising the steps of: applying a thin transparent film material having a thickness to a structure subject to vibrations; and measuring said vibrational energy within said structure by optically measuring changes in the thickness of said thin transparent film material resulting from vibrations within said structure transmitted to said thin transparent film material.
Claim 2
Independent Claim
64 words
A method for sensing and measuring vibrational energy in a structure comprising the steps of: applying a thin transparent film material having a thickness to a structure subject to vibrations; and measuring said vibrational energy within said structure by optically measuring changes in the thickness of said thin transparent film material resulting from vibrations within said structure transmitted to said thin transparent film material.
Claim 3
Dependent Claim
65 words
The method of claim 1 wherein said measuring step comprises: illuminating surfaces of said thin transparent film material; and monitoring said changes in the thickness of said thin transparent film material by measuring the phase differences between a first beam reflected by a first one of said surfaces and a second beam reflected by a second one of said surfaces caused by said thickness changes.
Claim 4
Dependent Claim
38 words
The method of claim 1 wherein said applying step comprises: providing a thin film of oil positioned between two layers of transparent plastic material; and coupling a bottom one of said layers of plastic material to said structure.
Claim 5
Dependent Claim
36 words
The method of claim 1 wherein said applying step comprises: providing a thin film dielectric material having reflective top and bottom surfaces; and coupling said bottom surface of said thin film dielectric material to said structure.
Claim 6
Independent Claim
106 words
A method for sensing and measuring vibrational energy in a structure comprising the steps of: applying a thin transparent film material having a thickness to a structure subject to vibrations; measuring said vibrational energy within said structure by measuring changes in the thickness of said thin transparent film material resulting from vibrations within said structure transmitted to said thin transparent film material; illuminating surfaces of said thin film material with a light beam; and monitoring changes in a resulting fringe pattern in said thin film material caused by said changes in the thickness of said thin transparent film material to obtain data about said vibrational energy.
Claim 7
Independent Claim
106 words
A method for sensing and measuring vibrational energy in a structure comprising the steps of: applying a thin transparent film material having a thickness to a structure subject to vibrations; measuring said vibrational energy within said structure by measuring changes in the thickness of said thin transparent film material resulting from vibrations within said structure transmitted to said thin transparent film material; illuminating surfaces of said thin film material with a light beam; and monitoring changes in a resulting fringe pattern in said thin film material caused by said changes in the thickness of said thin transparent film material to obtain data about said vibrational energy.
Claim 8
Dependent Claim
19 words
The method of claim 5 wherein said illuminating step comprises illuminating said surfaces with a beam of coherent light.
Claim 9
Dependent Claim
17 words
The method of claim 5 wherein said illuminating step comprises illuminating said surfaces with a laser beam.
Claim 10
Independent Claim
116 words
A method for sensing and measuring vibrational energy in a structure comprising the steps of: applying a thin transparent film material having a thickness to a structure subject to vibrations; measuring said vibrational energy within said structure by measuring changes in the thickness of said thin transparent film material resulting from vibrations within said structure transmitted to said thin transparent film material; providing at least one optical fiber for detecting said changes in thickness of said thin transparent film material, said measuring step further including illuminating surfaces of said thin film material with a light beam; and providing at least one lens to focus light reflected by said surfaces onto said at least one optical fiber.
Claim 11
Independent Claim
116 words
A method for sensing and measuring vibrational energy in a structure comprising the steps of: applying a thin transparent film material having a thickness to a structure subject to vibrations; measuring said vibrational energy within said structure by measuring changes in the thickness of said thin transparent film material resulting from vibrations within said structure transmitted to said thin transparent film material; providing at least one optical fiber for detecting said changes in thickness of said thin transparent film material, said measuring step further including illuminating surfaces of said thin film material with a light beam; and providing at least one lens to focus light reflected by said surfaces onto said at least one optical fiber.
Claim 12
Dependent Claim
39 words
The method of claim 8 further comprising: coupling a photodiode to said at least one optical fiber to detect said changes in thickness of said thin transparent film material by measuring changes in said light reflected by said surfaces.
Claim 13
Independent Claim
64 words
An apparatus for sensing and measuring vibrational energy in a structure which comprises: a thin transparent film material having a thickness coupled to a structure subject to vibrations; and means for optically measuring the vibrational energy within said structure by measuring changes in the thickness of said thin transparent film material resulting from vibrations within said structure transmitted to said thin transparent film material.
Claim 14
Independent Claim
64 words
An apparatus for sensing and measuring vibrational energy in a structure which comprises: a thin transparent film material having a thickness coupled to a structure subject to vibrations; and means for optically measuring the vibrational energy within said structure by measuring changes in the thickness of said thin transparent film material resulting from vibrations within said structure transmitted to said thin transparent film material.
Claim 15
Dependent Claim
68 words
The apparatus of claim 10 wherein said measuring means comprises: means for illuminating surfaces of said thin transparent film material; and means for monitoring changes in the thickness of said thin transparent film material by measuring the phase differences between a first beam reflected by a first one of said surfaces and a second beam reflected by a second one of said surfaces caused by said thickness changes.
Claim 16
Dependent Claim
23 words
The apparatus of claim 10 wherein said thin transparent film material comprises a thin film of oil located within a transparent plastic material.
Claim 17
Dependent Claim
53 words
The apparatus of claim 12 further comprising: an optically transmissive epoxy material positioned adjacent a bottom surface of said transparent plastic material; a light reflective material positioned adjacent said epoxy material; and a stiff epoxy material positioned adjacent said light reflective material for bonding said thin transparent film material to said vibrating structure.
Claim 18
Dependent Claim
55 words
The apparatus of claim 10 wherein said thin transparent film material comprises: a dielectric thin film material having a top reflective surface and a lower surface; a metallic reflector adjacent said lower surface; and a layer of stiff epoxy material adjacent said metallic reflector for coupling said thin transparent film material to said vibrating structure.
Claim 19
Independent Claim
154 words
An apparatus for sensing and measuring vibrational energy in a structure which comprises: a thin transparent film material having a thickness coupled to a structure subject to vibrations; means for measuring the vibrational energy within said structure by measuring changes in the thickness of said thin transparent film material resulting from vibrations within said structure transmitted to said thin transparent film material; means for illuminating surfaces of said thin transparent film material; and means for monitoring changes in a resulting fringe pattern in said thin film material caused by said changes in the thickness of said thin transparent film material to obtain data about said vibrational energy; means for monitoring changes in the thickness of said thin transparent film material by measuring the phase differences between a first beam reflected by a first one of said surfaces and a second beam reflected by a second one of said surfaces caused by said thickness changes.
Claim 20
Independent Claim
154 words
An apparatus for sensing and measuring vibrational energy in a structure which comprises: a thin transparent film material having a thickness coupled to a structure subject to vibrations; means for measuring the vibrational energy within said structure by measuring changes in the thickness of said thin transparent film material resulting from vibrations within said structure transmitted to said thin transparent film material; means for illuminating surfaces of said thin transparent film material; and means for monitoring changes in a resulting fringe pattern in said thin film material caused by said changes in the thickness of said thin transparent film material to obtain data about said vibrational energy; means for monitoring changes in the thickness of said thin transparent film material by measuring the phase differences between a first beam reflected by a first one of said surfaces and a second beam reflected by a second one of said surfaces caused by said thickness changes.
Claim 21
Dependent Claim
18 words
The apparatus of claim 15 wherein said illuminating means comprises means for generating a coherent beam of light.
Claim 22
Dependent Claim
16 words
The apparatus of claim 15 wherein said illuminating means comprises means for generating a laser beam.
Claim 23
Independent Claim
147 words
An apparatus for sensing and measuring vibrational energy in a structure which comprises: a thin transparent film material having a thickness coupled to a structure subject to vibrations; means for measuring the vibrational energy within said structure by measuring changes in the thickness of said thin transparent film material resulting from vibrations within said structure transmitted to said thin transparent film material; said means for measuring vibrational including at least one optical fiber for detecting said changes in said thickness of said transparent film material; and said means for measuring vibrational energy further comprising means for illuminating surfaces of said thin film material with a light beam and at least one lens for focussing light reflected by said surfaces onto said at least one optical fiber; a layer of stiff epoxy material adjacent said metallic reflector for coupling said thin transparent film material to said vibrating structure.
Claim 24
Independent Claim
147 words
An apparatus for sensing and measuring vibrational energy in a structure which comprises: a thin transparent film material having a thickness coupled to a structure subject to vibrations; means for measuring the vibrational energy within said structure by measuring changes in the thickness of said thin transparent film material resulting from vibrations within said structure transmitted to said thin transparent film material; said means for measuring vibrational including at least one optical fiber for detecting said changes in said thickness of said transparent film material; and said means for measuring vibrational energy further comprising means for illuminating surfaces of said thin film material with a light beam and at least one lens for focussing light reflected by said surfaces onto said at least one optical fiber; a layer of stiff epoxy material adjacent said metallic reflector for coupling said thin transparent film material to said vibrating structure.
Claim 25
Dependent Claim
40 words
The apparatus of claim 18 further comprising: a photodiode coupled to said at least one optical fiber to detect said changes in said thickness of said thin transparent film material by measuring changes in the light reflected by said surfaces.
Claim 26
Dependent Claim
39 words
A detector for use in an apparatus optically measuring vibrational energy in a structure subject to vibrations, said detector comprising: a thin film of oil contained within a transparent plastic containment pouch, said pouch having top and bottom surfaces.
Claim 27
Dependent Claim
39 words
A detector for use in an apparatus optically measuring vibrational energy in a structure subject to vibrations, said detector comprising: a thin film of oil contained within a transparent plastic containment pouch, said pouch having top and bottom surfaces.
Claim 28
Dependent Claim
15 words
The detector of claim 20 further comprising: a metallic reflector bonded to said bottom surface.
Claim 29
Dependent Claim
19 words
The detector of claim 20 further comprising: means for coupling said containment pouch to said structure subject to vibrations.
Claim 30
Dependent Claim
83 words
A detector for use in an apparatus optically measuring vibrational energy in a structure subject to vibrations, said detector comprising a thin film dielectric material having top and bottom surfaces which are reflective, said dielectric material being transparent so as to allow light to pass through said dielectric material and reflect off said bottom surface, and said dielectric material having at least one of said surfaces in contact with said structure so that vibrations in said structure are transmitted to said dielectric material.
Claim 31
Dependent Claim
83 words
A detector for use in an apparatus optically measuring vibrational energy in a structure subject to vibrations, said detector comprising a thin film dielectric material having top and bottom surfaces which are reflective, said dielectric material being transparent so as to allow light to pass through said dielectric material and reflect off said bottom surface, and said dielectric material having at least one of said surfaces in contact with said structure so that vibrations in said structure are transmitted to said dielectric material.
Claim 32
Dependent Claim
20 words
The detector of claim 23 wherein said thin film material comprises a magnesium fluoride sputtered onto a thin metallic sheet.
Claim 33
Dependent Claim
23 words
The detector of claim 23 wherein the bottom reflective surface of said thin film material is formed by a layer of aluminum material.
Claim 34
Dependent Claim
14 words
The detector of claim 23 wherein said thin film dielectric material comprises magnesium fluoride.
Claim 35
Dependent Claim
18 words
The detector of claim 23 further comprising: means for coupling said thin film dielectric material to said structure.
Claim 36
Dependent Claim
26 words
The detector of claim 27 wherein said coupling means comprises an epoxy material which is stiff relative to the stiffness of said thin film dielectric material.
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) | 1999-05-07 | 1999-11-06 | 2000-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-05-07 | 2003-11-06 | 2004-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-05-07 | 2007-11-06 | 2008-05-07 | $7700.00 | Window Closed / Lapsed |