Patent US5396079A successfully refreshed from Google Patents.
US5396079A
Expired / Lapsed
US
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Fiber optic detector and depth sensor and method for doing same
Assignee: Michigan Technological University
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Filing: 1993-07-06
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Granted: 1995-03-07
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Expires: 2013-07-06
Abstract
Abstract A fiber optic sensor for determining the presence and/or measuring the depth of a first substance capable of transmitting light. The fiber optic sensor includes a plurality of light receiving fibers, a plurality of light transmitting fibers surrounding the light receiving fibers and structure for refracting light from the light transmitting fibers at a predetermined angle for total internal reflection of the light from an interface of the first substance with a second substance.
Inventors
- 👤 Lawrence W. Evers
- 👤 Kenneth J. Jackson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:43
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/28; G01F23/284; G01F23/292; G01F23/2921; G01F23/2922; G01F23/2925; G01B; G01B11/00; G01B11/02; G01B11/06; G01N; G01N21/00; G01N21/84; G01N21/85; G01N21/8507; Y; Y10; Y10S; Y10S250/00; Y10S250/90; Y10S250/901; Y10S250/902; Y10S250/903
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
80 words
A fiber optic fluid depth sensor for measuring the depth a fluid interfacing with a second substance, said sensor comprising: a plurality of light receiving fibers; a plurality of light transmitting fibers; means for transmitting light to said light transmitting fibers; and means for refracting light from said light transmitting fibers at a predetermined angle so that light striking the interface of the fluid with the second substance will be totally internally reflected and received by said light receiving fibers.
Claim 2
Dependent Claim
80 words
A fiber optic fluid depth sensor for measuring the depth a fluid interfacing with a second substance, said sensor comprising: a plurality of light receiving fibers; a plurality of light transmitting fibers; means for transmitting light to said light transmitting fibers; and means for refracting light from said light transmitting fibers at a predetermined angle so that light striking the interface of the fluid with the second substance will be totally internally reflected and received by said light receiving fibers.
Claim 3
Dependent Claim
30 words
A fiber optic fluid depth sensor as set forth in claim 1 wherein said refracting means includes a reflector disposed between said light receiving fibers and said light transmitting fibers.
Claim 4
Dependent Claim
29 words
A fiber optic fluid depth sensor as set forth in claim 2 wherein said reflector includes an inclined surface with respect to an optical axis at said predetermined angle.
Claim 5
Dependent Claim
31 words
A fiber optic fluid depth sensor as set forth in claim 1 including means receiving the light from said light receiving fibers for producing a current proportional to the light received.
Claim 6
Dependent Claim
19 words
A fiber optic fluid depth sensor as set forth in claim 4 wherein said receiving means includes a photodiode.
Claim 7
Dependent Claim
25 words
A fiber optic fluid depth sensor as set forth in claim 1 including a sheath disposed about said light receiving fibers to form a bundle.
Claim 8
Dependent Claim
20 words
A fiber optic fluid depth sensor as set forth in claim 1 including a housing encompassing said light transmitting fibers.
Claim 9
Dependent Claim
21 words
A fiber optic fluid depth sensor as set forth in claim 7 wherein said housing includes a recess at one end.
Claim 10
Dependent Claim
19 words
A fiber optic fluid depth sensor as set forth in claim 8 including a cover disposed in said recess.
Claim 11
Independent Claim
127 words
A method of measuring the depth of a fluid using a fiber optic fluid depth sensor, said method comprising the steps of: surrounding a plurality of light receiving fibers with a plurality of light transmitting fibers in a fiber optic fluid depth sensor; disposing the fiber optic fluid depth sensor in a first fluid; transmitting light from a light source through the transmitting fibers; refracting light from the transmitting fibers at a predetermined angle toward an interface between the first fluid and a second fluid; reflecting light from the interface at an angle equal to or greater than a critical angle of the first and second fluids; and receiving the reflected light with the receiving fibers which receive the light by total internal reflection from the interface.
Claim 12
Independent Claim
127 words
A method of measuring the depth of a fluid using a fiber optic fluid depth sensor, said method comprising the steps of: surrounding a plurality of light receiving fibers with a plurality of light transmitting fibers in a fiber optic fluid depth sensor; disposing the fiber optic fluid depth sensor in a first fluid; transmitting light from a light source through the transmitting fibers; refracting light from the transmitting fibers at a predetermined angle toward an interface between the first fluid and a second fluid; reflecting light from the interface at an angle equal to or greater than a critical angle of the first and second fluids; and receiving the reflected light with the receiving fibers which receive the light by total internal reflection from the interface.
Claim 13
Dependent Claim
26 words
A method as set forth in claim 10 and further including the step of converting the light received by the receiving fibers into an electrical current.
Claim 14
Dependent Claim
22 words
A method as set forth in claim 11 and further including the step of converting said electrical current into an electrical voltage.
Claim 15
Dependent Claim
35 words
A method as set forth in claim 12 and further including the step of comparing said electrical voltage to a calibrated curve for voltage output versus depth to determine the depth of the first fluid.
Claim 16
Independent Claim
165 words
A method of measuring the depth of a fluid using a fiber optic fluid depth sensor, said method comprising the steps of: surrounding a means of light receiving fibers with a plurality of light transmitting fibers in a fiber optic fluid depth sensor; disposing fiber optic fluid depth sensor in a first fluid; transmitting light from a light source through the transmitting fibers; refracting light from the transmitting fibers at a predetermined angle toward an interface between the first fluid and a second fluid; reflecting light from the interface at an angle equal to or greater than a critical angle of the first and second fluids; and receiving the reflected light with the receiving fibers which transmit the light by total internal reflection; converting the light received by the receiving fibers into an electrical current; converting the electrical current into an electrical voltage; and comparing the electrical voltage to a calibrated curve for voltage output versus depth to determine the depth of the fluid measured.
Claim 17
Independent Claim
165 words
A method of measuring the depth of a fluid using a fiber optic fluid depth sensor, said method comprising the steps of: surrounding a means of light receiving fibers with a plurality of light transmitting fibers in a fiber optic fluid depth sensor; disposing fiber optic fluid depth sensor in a first fluid; transmitting light from a light source through the transmitting fibers; refracting light from the transmitting fibers at a predetermined angle toward an interface between the first fluid and a second fluid; reflecting light from the interface at an angle equal to or greater than a critical angle of the first and second fluids; and receiving the reflected light with the receiving fibers which transmit the light by total internal reflection; converting the light received by the receiving fibers into an electrical current; converting the electrical current into an electrical voltage; and comparing the electrical voltage to a calibrated curve for voltage output versus depth to determine the depth of the fluid measured.
Claim 18
Independent Claim
127 words
A method of determining the presence of a first substance on a surface using a fiber optic sensor, said method comprising the steps of: surrounding a plurality of light receiving fibers with a plurality of light transmitting fibers in a fiber optic sensor; disposing the fiber optic sensor in the surface; transmitting light from a light source through the transmitting fibers; refracting light from the transmitting fibers at a predetermined angle so that light strikes any interface that may be present between the first substance and a second substance at an angle equal to or greater than a critical angle for the first and second substances; reflecting light from the interface if the first substance is present; and receiving the reflected light with the light receiving fibers.
Claim 19
Independent Claim
127 words
A method of determining the presence of a first substance on a surface using a fiber optic sensor, said method comprising the steps of: surrounding a plurality of light receiving fibers with a plurality of light transmitting fibers in a fiber optic sensor; disposing the fiber optic sensor in the surface; transmitting light from a light source through the transmitting fibers; refracting light from the transmitting fibers at a predetermined angle so that light strikes any interface that may be present between the first substance and a second substance at an angle equal to or greater than a critical angle for the first and second substances; reflecting light from the interface if the first substance is present; and receiving the reflected light with the light receiving fibers.
Claim 20
Dependent Claim
86 words
A fiber optic sensor for detecting the presence of a first substance, said sensor comprising: a plurality of light receiving fibers; a plurality of light transmitting fibers; means for transmitting light to said light transmitting fibers; and means for refracting light from said light transmitting fibers at a predetermined angle toward any interface of the first substance and a second substance whereby if the first substance is present, light from the interface is totally internally reflected by the interface and received by the light receiving fibers.
Claim 21
Dependent Claim
86 words
A fiber optic sensor for detecting the presence of a first substance, said sensor comprising: a plurality of light receiving fibers; a plurality of light transmitting fibers; means for transmitting light to said light transmitting fibers; and means for refracting light from said light transmitting fibers at a predetermined angle toward any interface of the first substance and a second substance whereby if the first substance is present, light from the interface is totally internally reflected by the interface and received by the light receiving fibers.
Claim 22
Dependent Claim
18 words
A fiber optic sensor as set forth in claim 16 wherein said refracting means includes an inclined surface.
Claim 23
Dependent Claim
29 words
A fiber optic sensor as set forth in claim 16 including means receiving the light from said light receiving fibers for producing a current proportional to the light received.
Claim 24
Dependent Claim
17 words
A fiber optic sensor as set forth in claim 18 wherein said receiving means includes a photodiode.
Claim 25
Dependent Claim
82 words
A fiber optic depth sensor for measuring the depth of a first substance interfacing with a second substance, said sensor comprising: a plurality of light receiving fibers; a plurality of light transmitting fibers; means for transmitting light to said light transmitting fibers; and means for refracting light from said light transmitting fibers at a predetermined angle so that light striking the interface of the first substance with the second substance will be totally internally reflected and received by said light receiving fibers.
Claim 26
Dependent Claim
82 words
A fiber optic depth sensor for measuring the depth of a first substance interfacing with a second substance, said sensor comprising: a plurality of light receiving fibers; a plurality of light transmitting fibers; means for transmitting light to said light transmitting fibers; and means for refracting light from said light transmitting fibers at a predetermined angle so that light striking the interface of the first substance with the second substance will be totally internally reflected and received by said light receiving fibers.
Claim 27
Dependent Claim
29 words
A fiber optic depth sensor as set forth in claim 20 wherein said refracting means includes a reflector disposed between said light receiving fibers and said light transmitting fibers.
Claim 28
Dependent Claim
28 words
A fiber optic depth sensor as set forth in claim 21 wherein said reflector includes an inclined surface with respect to an optical axis at said predetermined angle.
Claim 29
Dependent Claim
30 words
A fiber optic depth sensor as set forth in claim 20 including means receiving the light from said light receiving fibers for producing a current proportional to the light received.
Claim 30
Dependent Claim
18 words
A fiber optic depth sensor as set forth in claim 23 wherein said receiving means includes a photodiode.
Claim 31
Independent Claim
108 words
A method of measuring the depth of a substance, said method comprising the steps: supplying a plurality of light transmitting fibers; supplying a plurality of light receiving fibers; transmitting light from a light source through the light transmitting fibers; refracting light exiting the light transmitting fibers at a predetermined angle; transmitting the refracted light through the depth of the substance; reflecting the light that travels through the substance when the light strikes an interface between the substance and a second substance; receiving the reflected light with the light receiving fibers; calculating the depth of the substance based upon the amount of light received by the light receiving fibers.
Claim 32
Independent Claim
108 words
A method of measuring the depth of a substance, said method comprising the steps: supplying a plurality of light transmitting fibers; supplying a plurality of light receiving fibers; transmitting light from a light source through the light transmitting fibers; refracting light exiting the light transmitting fibers at a predetermined angle; transmitting the refracted light through the depth of the substance; reflecting the light that travels through the substance when the light strikes an interface between the substance and a second substance; receiving the reflected light with the light receiving fibers; calculating the depth of the substance based upon the amount of light received by the light receiving fibers.
Claim 33
Dependent Claim
24 words
A fiber optic fluid depth sensor as set forth in claim 1 wherein said plurality of light transmitting fibers surrounds said light receiving fibers.
Claim 34
Dependent Claim
22 words
A fiber optic sensor as set forth in claim 16 wherein said plurality of light transmitting fibers surrounds said light receiving fibers.
Claim 35
Dependent Claim
23 words
A fiber optic depth sensor as set forth in claim 20 wherein said plurality of light transmitting fibers surround said light receiving fibers.
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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) | 1998-03-06 | 1998-09-05 | 1999-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-03-06 | 2002-09-05 | 2003-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-03-06 | 2006-09-05 | 2007-03-07 | $7700.00 | Window Closed / Lapsed |