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US5710430A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for terahertz imaging

Assignee: Nokia of America Corp
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Filing: 1996-09-10
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Granted: 1998-01-20
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Expires: 2016-09-10
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Abstract

Abstract Certain material and objects can be characterized by a frequency-dependent absorption, dispersion, and reflection of terahertz transients in signals which pass illuminate the material or object. The present terahertz imaging system analyses that frequency dependence in the time-domain by collecting that transmitted signal propagating through the object and then processing the information contained in those signals for every point or "pixel" on that object. This is a non-invasive imaging technique that is capable of differentiating between different materials, chemical compositions, or environments.

Inventors

  • 👤 Martin C. Nuss

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 02:24
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/35; G01N21/3581; G01N21/3586; G01N21/47; G01N21/49; G01R; G01R31/00; G01R31/28; G01R31/302; G01R31/308

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 107 words
A method of inspecting a medium having one or more absorptive, dispersive, or reflective constituents, comprising the steps of: directing a pulsed sequence of electromagnetic signals that are in the frequency range between 100 GHz to 20 THz at said medium, wherein the pulsed sequence is selected so as to permit observation of frequency dependent variations in the absorption, dispersion, or reflectivity of at least one constituent of the medium; and detecting the directed pulse signals following propagation through the medium, the detected pulse signals being characterized by temporal distortions related to said frequency dependent variations, to thereby obtain spectral information about said constituents in real time.
Claim 2
Independent Claim 107 words
A method of inspecting a medium having one or more absorptive, dispersive, or reflective constituents, comprising the steps of: directing a pulsed sequence of electromagnetic signals that are in the frequency range between 100 GHz to 20 THz at said medium, wherein the pulsed sequence is selected so as to permit observation of frequency dependent variations in the absorption, dispersion, or reflectivity of at least one constituent of the medium; and detecting the directed pulse signals following propagation through the medium, the detected pulse signals being characterized by temporal distortions related to said frequency dependent variations, to thereby obtain spectral information about said constituents in real time.
Claim 3
Dependent Claim 24 words
The method according to claim 1, further including a step of: analyzing the temporal distortions in the time domain to obtain said spectral information.
Claim 4
Dependent Claim 26 words
The method according to claim 2, further including a step of: creating an image of said medium based on spectral information obtained during said analyzing step.
Claim 5
Dependent Claim 28 words
The method according to claim 2, further including a step of: identifying at least one constituent of the medium based on spectral information obtained during said analyzing step.
Claim 6
Dependent Claim 29 words
The method according to claim 4, wherein said identifying step includes comparing spectral information obtained during said analyzing step with stored spectral information associated with a plurality of compositions.
Claim 7
Dependent Claim 27 words
The method according to claim 1, wherein said directing step includes causing said electromagnetic signals to propagate along a plurality of spatiaily distinct paths through said medium.
Claim 8
Dependent Claim 39 words
The method according to claim 1, wherein said directing step includes causing said electromagnetic signals to propagate along a plurality of spatially distinct paths so as to be incident on a plurality of spatially distinct areas of the medium.
Claim 9
Independent Claim 123 words
An apparatus for inspecting a medium having one or more absorptive, dispersive, or reflective constituents, comprising: a transmitter for directing a pulsed sequence of electromagnetic signals that are in the frequency range between 100 GHz to 20 THz at said medium, wherein the pulsed sequence is selected so as to permit observation of frequency dependent variations in the absorption, dispersion, or reflectivity of at least one constituent of the medium; and a detector for detecting the pulsed sequence following propagation through the medium, the detected pulsed sequence being characterized by temporal distortions related to said frequency dependent variations in the absorption, dispersion, or reflectivity of at least one constituent of the medium, to thereby obtain spectral information about said constituents in real time.
Claim 10
Independent Claim 123 words
An apparatus for inspecting a medium having one or more absorptive, dispersive, or reflective constituents, comprising: a transmitter for directing a pulsed sequence of electromagnetic signals that are in the frequency range between 100 GHz to 20 THz at said medium, wherein the pulsed sequence is selected so as to permit observation of frequency dependent variations in the absorption, dispersion, or reflectivity of at least one constituent of the medium; and a detector for detecting the pulsed sequence following propagation through the medium, the detected pulsed sequence being characterized by temporal distortions related to said frequency dependent variations in the absorption, dispersion, or reflectivity of at least one constituent of the medium, to thereby obtain spectral information about said constituents in real time.
Claim 11
Dependent Claim 26 words
The apparatus according to claim 8, further including means for causing said electromagnetic signals to propagate along a plurality of spatially distinct paths through said medium.
Claim 12
Dependent Claim 38 words
The apparatus according to claim 8, further including means for causing said electromagnetic signals to propagate along a plurality of spatially distinct paths so as to be incident on a plurality of spatially distinct areas of the medium.
Claim 13
Dependent Claim 25 words
The apparatus according to claim 10, further including analyzing means coupled to the detector for analyzing the temporal distortions to thereby obtain said spectral information.
Claim 14
Dependent Claim 44 words
The apparatus according to claim 11, further including means for storing spectral information relating to a plurality of compositions and wherein said analyzing means comprises means for comparing obtained spectral information with said stored spectral information to thereby identify a constituent of the medium.

References Cited (Backward Citations)

US5148022A Cited
US5441054A Cited
US5371368A Cited
US5477051A Cited
US5623145A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-01-19 2001-07-21 2002-01-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-01-19 2005-07-21 2006-01-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-01-19 2009-07-21 2010-01-20 $7700.00 Window Closed / Lapsed

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