US4451730A
Expired / Lapsed
US
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Optical measuring apparatus for measuring force or pressure
Assignee: ABB Norden Holding AB
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Filing: 1983-05-09
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Granted: 1984-05-29
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Expires: 2003-05-09
Abstract
Abstract An optical measuring apparatus for measuring force or pressure, having at least one light source, at least one optical fiber for passing light from and to a sensor, and one detector system. The sensor includes a material having pressure- and force-dependent photo luminescence properties, the signal received in the detector system being dependent on the pressure or the force applied to the sensor.
Inventors
- 👤 Torgny Brogardh
- 👤 Olof Engstrom
- 👤 Christer Ovren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:23
CPC Classifications
G; G01; G01L; G01L11/00; G01L11/02; G01L1/00; G01L1/24
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
126 words
An optical measuring apparatus for measuring a force, comprising at least one light source, an optical fiber system comprising at least one optical fiber for conducting at least one frequency of light from and to a sensing means, and a detector system, wherein said sensing means comprises a material having force-dependent photo-luminescent properties, such that a wavelength shift of the entire spectrum of the emitted photo-luminescent light from said sensing means is produced within at least two different wavelength ranges as a function of the force applied to said sensing means, said optical fiber system directing said photo-luminescent light from said sensing means to said detector system, and said detector system including means for detecting said photo-luminescent light within said at least two different wavelength ranges.
Claim 2
Dependent Claim
126 words
An optical measuring apparatus for measuring a force, comprising at least one light source, an optical fiber system comprising at least one optical fiber for conducting at least one frequency of light from and to a sensing means, and a detector system, wherein said sensing means comprises a material having force-dependent photo-luminescent properties, such that a wavelength shift of the entire spectrum of the emitted photo-luminescent light from said sensing means is produced within at least two different wavelength ranges as a function of the force applied to said sensing means, said optical fiber system directing said photo-luminescent light from said sensing means to said detector system, and said detector system including means for detecting said photo-luminescent light within said at least two different wavelength ranges.
Claim 3
Dependent Claim
32 words
An optical measuring apparatus according to claim 1, wherein the detector system includes means for detecting light, for example excitation light from the said light source, reflected from the said sensing means.
Claim 4
Dependent Claim
19 words
An optical measuring apparatus according to claim 1, wherein said at least one light source comprises a lightemitting diode.
Claim 5
Dependent Claim
19 words
An optical measuring apparatus according to claim 1, wherein said at least one light source comprises a Schottky diode.
Claim 6
Dependent Claim
19 words
An optical measuring apparatus according to claim 1, wherein said at least one light source comprises a semiconductor laser.
Claim 7
Dependent Claim
26 words
An optical measuring apparatus according to claim 1, wherein said detector system includes at least two photo-detectors for receiving said photo-luminescent light from said sensing means.
Claim 8
Dependent Claim
15 words
An optical measuring apparatus according to claim 6, wherein said photo-detectors have non-identical spectral responses.
Claim 9
Dependent Claim
21 words
An optical measuring apparatus according to claim 6, wherein at least one of said photo-detectors is provided with an optical filter.
Claim 10
Dependent Claim
23 words
An optical measuring apparatus according to claim 6, wherein said optical fiber system is arranged to direct photo-luminescent light directly towards the photo-detectors.
Claim 11
Dependent Claim
27 words
An optical measuring apparatus according to claim 6, wherein optical lens means is arranged to focus optical signals from said optical fiber system on to said photo-detectors.
Claim 12
Dependent Claim
54 words
An optical measuring apparatus according to claim 6, wherein a partially transparent mirror is positioned so that one of said photo-detectors receives optical signals from said optical fiber system which pass through said mirror and the other of said photo-detectors receives optical signals from said optical fiber system which are reflected from said mirror.
Claim 13
Dependent Claim
42 words
An optical measuring apparatus according to claim 6, wherein interference means is provided for dividing said photo-luminescent light from said optical fiber system into partial signals within different wavelength ranges, the different partial signals being directed towards different ones of said photo-detectors.
Claim 14
Dependent Claim
40 words
An optical measuring apparatus according to claim 6, wherein said optical fiber system has at least two optical fiber end portions facing towards said detector system, each of said end portions being arranged adjacent a different one of said photo-detectors.
Claim 15
Dependent Claim
25 words
An optical measuring apparatus according to claim 1, wherein said detector system comprises a detector in the form of a demultiplexed structure having p-n junctions.
Claim 16
Dependent Claim
20 words
An optical measuring apparatus according to claim 6, wherein electrical signals from said photo-detectors are subsequently processed in function-generating means.
Claim 17
Dependent Claim
16 words
An optical measuring apparatus according to claim 15, wherein said function-generating means comprises a quotient-forming means.
Claim 18
Dependent Claim
30 words
An optical measuring apparatus according to claim 1, wherein said sensing means comprises a first material intended to be subjected to the force to be measured, and a second material.
Claim 19
Dependent Claim
21 words
An optical measuring apparatus according to claim 17, wherein said first material has different light absorption properties from said second material.
Claim 20
Dependent Claim
20 words
An optical measuring apparatus according to claim 17, wherein said first material has different luminescence properties from said second material.
Claim 21
Dependent Claim
83 words
An optical measuring apparatus according to claim 17, wherein two light sources are provided which are arranged to transmit light, along a common portion of said optical fiber system, to said sensing means, one of said first and second materials serving as an optical filter in the ray path to the other of the said first and second materials to enable light, emanating from said two light sources, to be absorbed to a different extent in each of said first and second materials.
Claim 22
Dependent Claim
31 words
An optical measuring apparatus according to claim 6, wherein one of said photo-detectors has a transmission response which is substantially linear relative to the photon-energy of the photo-luminescent light detected thereby.
Claim 23
Dependent Claim
45 words
An optical measuring apparatus according to claim 6, wherein one of said photo-detectors is provided with an optical filter, said one photo-detector and said optical filter having a transmission response which is substantially linear relative to the photon energy of the photo-luminescent light detected thereby.
Claim 24
Dependent Claim
60 words
An optical measuring apparatus according to claim 1, wherein an optical filter is arranged relative to said sensing means so that the photo-luminescent light emitted from said sensing means is arranged to pass through said optical filter, said optical filter having a transmission response which is temperature-dependent in at least substantially the same manner as that of said sensing means.
Claim 25
Dependent Claim
27 words
An optical measuring apparatus according to claim 23, wherein said sensing means comprises a first material which is the same material as that of said optical filter.
Claim 26
Dependent Claim
65 words
An optical measuring apparatus according to claim 23, wherein said at least one frequency of light comprises a first frequency and a second frequency and wherein there is provided means for transmitting said second frequency of light through said sensing means, said second frequency of light being transparent to said second frequency of light which is intended to be used for compensation of measuring errors.
Claim 27
Dependent Claim
18 words
An optical measuring apparatus according to claim 1, wherein said sensing means comprises at least one semiconductor material.
Claim 28
Dependent Claim
84 words
An optical measuring apparatus according to claim 26, wherein said at least one semiconductor material is selected from the group consisting of AlP, AlAs, GaP, GaAs, InP, InAs, In 1-x Al x P, In 1-x Ga x P, Ga 1-x Al x P, In 1-x Al x As, In 1-x Ga x As, Ga 1-x Al x As, InAs 1-y P y , GaAs 1-y P y , x and y being between 0 and 1, ZnTe, ZnSe, ZnS, ZnO, CdTe, CdSe and CdS.
Claim 29
Dependent Claim
24 words
An optical measuring apparatus according to claim 26, wherein said at least one semiconductor material comprises GaP doped with Zn and O 2 .
Claim 30
Dependent Claim
24 words
An optical measuring apparatus according to claim 26, wherein said at least one semiconductor material comprises GaP doped with Ce and O 2 .
Claim 31
Dependent Claim
22 words
An optical measuring apparatus according to claim 26, wherein said at least one semiconductor material comprises GaP doped with N 2 .
Claim 32
Dependent Claim
20 words
An optical measuring apparatus according to claim 26, wherein said at least one semiconductor material comprises ZnSe doped with Cu.
Claim 33
Dependent Claim
20 words
An optical measuring apparatus according to claim 26, wherein said at least one semiconductor material comprises ZnSe doped with Mn.
Claim 34
Dependent Claim
24 words
An optical measuring apparatus according to claim 26, wherein said at least one semiconductor material comprises Al x Ga 1-x As doped with Ge.
Claim 35
Dependent Claim
24 words
An optical measuring apparatus according to claim 26, wherein said at least one semiconductor material comprises Al x Ga 1-x As doped with Si.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1987-05-29 | 1987-11-28 | 1988-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-29 | 1991-11-28 | 1992-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-29 | 1995-11-28 | 1996-05-29 | $7700.00 | Window Closed / Lapsed |