Patent US3828126A successfully refreshed from Google Patents.
US3828126A
Expired / Lapsed
US
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Real time interferometry
Assignee: American Express Investment Management Co
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Filing: 1973-04-13
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Granted: 1974-08-06
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Expires: 1993-04-13
Abstract
Abstract A real time holographic interferometer for measuring deformation of objects. Four independent holographic interference patterns are formed with on-axis object and reference beams. The first two interference patterns are of the object in a first physical state, e.g., in its first state of stress, or of a reference plane, and the second two interference patterns are of the object in a second physical state, e.g., in its second state of stress. The phase of the reference beam is shifted 90* for each exposure. A storage-type television camera is employed for generating output signals that contain information from the four interference patterns. The first three output signals of the camera are stored in video recorders and are retrieved synchronously with the fourth camera output signals. Two signal pairs each consisting of a signal of the first and second states of stress of the object are combined and subtracted to form difference signals which are thereafter electronically squared and summed to generate a processed signal that contains the desired deformation information. The processed signal is utilized such as for driving a cathode ray tube.
Inventors
- 👤 S Ramsey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:00
CPC Classifications
G; G01; G01B; G01B9/00; G01B9/02; G01B9/021; Y; Y10; Y10S; Y10S359/00; Y10S359/90; Y10S359/902
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
223 words
Apparatus for measuring small dimensional changes in an object by real time hologram interferometry comprising: means for sequentially illuminating a surface of a first object at least twice to form first and second scattered and reflected object beams respectively; means for sequentially illuminating a surface of a second object at least twice to sequentially form third and fourth scattered and reflected object beams; means for generating a reference light beam; means for shifting the phase of the reference light beam by equal increments to form a number of phase shifted reference beams equal to the number of object beams; means for sequentially combining the first through fourth scattered and reflected object beams with the phase shifted reference light beams to form individual first through fourth interference patterns; a storage-type television camera tube having a visual input and for converting the visual input to an electrical output positioned to receive as an input said interference patterns and to generate therefrom first through fourth electrical output signals; means for storing at least the first three electrical output signals of the television camera tube; means for combining the first through fourth electrical output signals of the television camera tube to form a processed signal containing position deformation information of the first and second object surfaces; and means for utilizing the processed signal containing position deformation informAtion.
Claim 2
Dependent Claim
223 words
Apparatus for measuring small dimensional changes in an object by real time hologram interferometry comprising: means for sequentially illuminating a surface of a first object at least twice to form first and second scattered and reflected object beams respectively; means for sequentially illuminating a surface of a second object at least twice to sequentially form third and fourth scattered and reflected object beams; means for generating a reference light beam; means for shifting the phase of the reference light beam by equal increments to form a number of phase shifted reference beams equal to the number of object beams; means for sequentially combining the first through fourth scattered and reflected object beams with the phase shifted reference light beams to form individual first through fourth interference patterns; a storage-type television camera tube having a visual input and for converting the visual input to an electrical output positioned to receive as an input said interference patterns and to generate therefrom first through fourth electrical output signals; means for storing at least the first three electrical output signals of the television camera tube; means for combining the first through fourth electrical output signals of the television camera tube to form a processed signal containing position deformation information of the first and second object surfaces; and means for utilizing the processed signal containing position deformation informAtion.
Claim 3
Dependent Claim
42 words
Apparatus according to claim 1 wherein the means for phase shifting comprises an electro-optic crystal through which the reference beam is passed, and including means for varying the voltage applied to the crystal to thereby shift the phase of the reference beam.
Claim 4
Dependent Claim
19 words
Apparatus according to claim 1 including means for storing the fourth electrical output signal from the television camera tube.
Claim 5
Dependent Claim
19 words
Apparatus according to claim 1 wherein the first and second objects comprise identical articles in first and second states.
Claim 6
Dependent Claim
35 words
Apparatus according to claim 4 wherein the article in the first state is in a state of relatively lesser stress and the article in the second state is in a state of relatively greater stress.
Claim 7
Dependent Claim
29 words
Apparatus according to claim 1 wherein the phase shifting means comprises means for shifting the phase by a factor 2 pi divided by the number of generated object beams.
Claim 8
Dependent Claim
11 words
Apparatus according to claim 6 wherein the factor is pi /2.
Claim 9
Dependent Claim
44 words
Apparatus according to claim 1 wherein the storing means comprises a video signal recorder for each storage camera output signal but the last output signal, and including means for retrieving the stored output signals in synchronism with the generation of the last output signal.
Claim 10
Dependent Claim
16 words
Apparatus according to claim 8 wherein the means for applying the signals comprises a synch generator.
Claim 11
Dependent Claim
35 words
Apparatus according to claim 1 wherein the means for utilizing the signal containing position deformation information comprises a limiter for removing original picture information and a spectrum analyzer for analyzing the remaining position deformation information.
Claim 12
Dependent Claim
43 words
Apparatus according to claim 10 wherein the combining means comprises means for subtracting said signals from each other to form difference signals, means for electronically squaring the difference signals, and means for adding the squared difference signals to thereby generate the processed signal.
Claim 13
Dependent Claim
16 words
Apparatus according to claim 1 wherein the surface of the first article comprises a reference surface.
Claim 14
Dependent Claim
13 words
Apparatus according to claim 12 wherein the reference surface is a flat surface.
Claim 15
Dependent Claim
21 words
Apparatus according to claim 12 wherein the reference surface is a regular surface different from the surface of the second object.
Claim 16
Dependent Claim
33 words
Apparatus according to claim 1 wherein the combining means comprises means for generating electric difference signals between the third and the first interference patterns and between the fourth and the second interference patterns.
Claim 17
Dependent Claim
13 words
Apparatus according to claim 15 including electronic means for squaring the difference signals.
Claim 18
Dependent Claim
20 words
Apparatus according to claim 16 including electronic summer means for adding the squared signals and thereby generating the processed signal.
Claim 19
Dependent Claim
17 words
Apparatus according to claim 17 wherein the utilizing means comprises a cathode ray tube for visual inspection.
Claim 20
Dependent Claim
237 words
Apparatus for measuring small dimensional changes in an object by real time hologram interferometry comprising: a. means for sequentially illuminating an object twice each in first and second states to form two first and two second scattered and reflected object beams, respectively; b. means for generating a reference light beam; c. phase shifting means for sequentially changing the phase of the reference beam by 90*; d. a storage television camera tube having a visual input and adapted to convert visual information to an electrical output; e. means for sequentially combining the four scattered and reflected object beams with the four phase shifted reference beams to form first through fourth individual interference patterns, respectively, the interference patterns each being stored as a visual input by the storage television camera tube; f. means for scanning the storage television camera tube sequentially producing four output signals of the four interference patterns; g. means for storing the first three of the four output signals; h. means for processing the four ouTput signals into a processed signal containing image information of the object and position deformation information about the objects between their two states, the processing means including means for combining output signals from interference patterns of the object in one state with output signals from interference patterns of the object in its other state; and i. inspecting means inspecting the processed signal to derive position deformation information about the object therefrom.
Claim 21
Dependent Claim
237 words
Apparatus for measuring small dimensional changes in an object by real time hologram interferometry comprising: a. means for sequentially illuminating an object twice each in first and second states to form two first and two second scattered and reflected object beams, respectively; b. means for generating a reference light beam; c. phase shifting means for sequentially changing the phase of the reference beam by 90*; d. a storage television camera tube having a visual input and adapted to convert visual information to an electrical output; e. means for sequentially combining the four scattered and reflected object beams with the four phase shifted reference beams to form first through fourth individual interference patterns, respectively, the interference patterns each being stored as a visual input by the storage television camera tube; f. means for scanning the storage television camera tube sequentially producing four output signals of the four interference patterns; g. means for storing the first three of the four output signals; h. means for processing the four ouTput signals into a processed signal containing image information of the object and position deformation information about the objects between their two states, the processing means including means for combining output signals from interference patterns of the object in one state with output signals from interference patterns of the object in its other state; and i. inspecting means inspecting the processed signal to derive position deformation information about the object therefrom.
Claim 22
Dependent Claim
286 words
Apparatus for measuring small dimension surface height contours of an object by real time hologram interferometry comprising: means for illuminating a standard reference surface at least twice to form first and second scattered and reflected object beams anf for illuminating the object whose surface height contours are to be measured at least twice to form third and fourth scattered and reflected object beams; means for generating a reference light beam; means for changing the reference light beam into at least four phase shifted reference light beams, each such phase shifted reference light beam having its phase shifted by equal increments to form a number of phase shifted reference beams equal to the number of object beams; a storage television camera tube for receiving a visual input and for converting the visual input to an electrical output; means for combining the first and second object beams scattered and reflected from the standard reference surface with the first two phase shifted reference light beams to form first and second interference patterns which are received by the storage camera tube, and for combining the third and fourth object beams scattered and reflected from the object surface with the third and fourth phase shifted reference light beams to form third and fourth interference patterns which are received by the storage camera tube; means for storing at least the first three output signals of the storage tube corresponding to the first three interference patterns; means for synchronously combining the output signals from the reference surface interference patterns with the output signals of the object surface interference patterns; and means for generating from the combined signals processed signals containing surface position height information about the object surface relative to the standard surface.
Claim 23
Dependent Claim
286 words
Apparatus for measuring small dimension surface height contours of an object by real time hologram interferometry comprising: means for illuminating a standard reference surface at least twice to form first and second scattered and reflected object beams anf for illuminating the object whose surface height contours are to be measured at least twice to form third and fourth scattered and reflected object beams; means for generating a reference light beam; means for changing the reference light beam into at least four phase shifted reference light beams, each such phase shifted reference light beam having its phase shifted by equal increments to form a number of phase shifted reference beams equal to the number of object beams; a storage television camera tube for receiving a visual input and for converting the visual input to an electrical output; means for combining the first and second object beams scattered and reflected from the standard reference surface with the first two phase shifted reference light beams to form first and second interference patterns which are received by the storage camera tube, and for combining the third and fourth object beams scattered and reflected from the object surface with the third and fourth phase shifted reference light beams to form third and fourth interference patterns which are received by the storage camera tube; means for storing at least the first three output signals of the storage tube corresponding to the first three interference patterns; means for synchronously combining the output signals from the reference surface interference patterns with the output signals of the object surface interference patterns; and means for generating from the combined signals processed signals containing surface position height information about the object surface relative to the standard surface.
Claim 24
Dependent Claim
13 words
Apparatus according to claim 20 wherein the standard surface is a plane surface.
Claim 25
Dependent Claim
14 words
Apparatus according to claim 20 wherein the standard surface comprises a smooth regular surface.
Claim 26
Dependent Claim
13 words
Apparatus according to claim 20 wherein the standard surface comprises a curved surface.
Claim 27
Dependent Claim
15 words
Apparatus according to claim 20 including means for utilizing the signal containing position height information.
Claim 28
Dependent Claim
14 words
Apparatus according to claim 24 wherein the utilizing means comprises a cathode ray tube.
Claim 29
Independent Claim
335 words
A method for measuring small dimension surface height contours on an object by real time hologram interferometry comprising: illuminating a standard reference surface to form a first scattered and reflected object beam; generating a first reference light beam; combining the first object beam with the first reference light beam to form a first interference pattern and projecting the first interference pattern on a storage television camera tube as a visual input; storing the resulting first electrical output of the television tube; generating a second reference light beam having a 90* phase shift with respect to the first light beam; combining the first object beam with the second reference light beam to form a second interference pattern and projecting the second interference pattern on the storage television camera tube as a visual input; storing the resulting second electrical output of the television camera tube; illuminating the object whose surface contours are to be measured to form a second scattered and reflected object beam; generating a third reference ligHt beam having a 180* phase shift relative to the first light beam; combining the second object beam with the third reference light beam to form a third interference pattern and projecting the third interference pattern on the storage television camera tube as a visual input; storing the resulting third electrical output of the television camera; generating a fourth reference light beam having a phase shift relative to the first reference light beam of 270*; combining the second scattered and reflected object beam with the fourth reference light beam to form a fourth interference pattern and projecting the fourth interference pattern on the storage television camera tube as a visual input; retrieving the stored first through third electrical outputs in synchronism with the generation of the fourth electrical output of the storage television camera tube; combining the third and fourth output signals with the first and second output signals; and generating therefrom a processed signal containing surface position height information about the object surface relative to the standard surface.
Claim 30
Independent Claim
335 words
A method for measuring small dimension surface height contours on an object by real time hologram interferometry comprising: illuminating a standard reference surface to form a first scattered and reflected object beam; generating a first reference light beam; combining the first object beam with the first reference light beam to form a first interference pattern and projecting the first interference pattern on a storage television camera tube as a visual input; storing the resulting first electrical output of the television tube; generating a second reference light beam having a 90* phase shift with respect to the first light beam; combining the first object beam with the second reference light beam to form a second interference pattern and projecting the second interference pattern on the storage television camera tube as a visual input; storing the resulting second electrical output of the television camera tube; illuminating the object whose surface contours are to be measured to form a second scattered and reflected object beam; generating a third reference ligHt beam having a 180* phase shift relative to the first light beam; combining the second object beam with the third reference light beam to form a third interference pattern and projecting the third interference pattern on the storage television camera tube as a visual input; storing the resulting third electrical output of the television camera; generating a fourth reference light beam having a phase shift relative to the first reference light beam of 270*; combining the second scattered and reflected object beam with the fourth reference light beam to form a fourth interference pattern and projecting the fourth interference pattern on the storage television camera tube as a visual input; retrieving the stored first through third electrical outputs in synchronism with the generation of the fourth electrical output of the storage television camera tube; combining the third and fourth output signals with the first and second output signals; and generating therefrom a processed signal containing surface position height information about the object surface relative to the standard surface.
Claim 31
Dependent Claim
33 words
A method according to claim 26 wherein the step of combining comprises the step of forming difference signals by subtracting the first and second output signals from the third and fourth output signals.
Claim 32
Dependent Claim
31 words
A method according to claim 27 wherein the step of generating the processed signal comprises the steps of electronically squaring the difference signals and thereafter electronically summing the squared difference signals.
Claim 33
Dependent Claim
15 words
A method according to claim 26 including the step of utilizing the processed output signal.
Claim 34
Dependent Claim
36 words
A method according to claim 29 wherein the step of utilizing comprises the step of forming a display of the object and surface position height information on a cathode ray tube, and visually observing the display.
Claim 35
Dependent Claim
25 words
A method according to claim 29 wherein the step of utilizing comprises the step of driving with the processed signal an automatic object reject-acceptance device.
Claim 36
Independent Claim
329 words
A method for measuring small dimension changes in an object by real time hologram interferometry comprising: illuminating the object in a first state to form a first scattered and reflected object beam; generating a first reference light beam; combining the first object beam with the first reference light beam to form a first interference pattern and projecting the first interference pattern on a storage television camera tube as a visual input; storing the resulting first electrical output of the television tube; generating a second reference light beam having a 90* phase shift with respect to the first light beam; combining the first object beam with the second reference light beam to form a second interference pattern and projecting the second interference pattern on the storage television camera tube as a visual input; storing the resulting second electrical output of the television camera tube; illuminating the object in a second state to form a second scattered and reflected object beam; generating a third reference light beam having a 180* phase shift relative to the first light beam; combining the second object beam with the third reference light beam to form a third interference pattern and projecting the third interference pattern on the storage television camera tube as a visual input; storing the resulting third electrical output of the television camera; generating a fourth reference light beam having a phase shift relative to the first reference light beam of 270*; combining the second scattered and reflected object beam with the fourth reference light beam to form a fourth interference pattern and projecting the fourth interference pattern on the storage television camera tube as a visual input; retrieving the stored first through third electrical outputs in synchronism with the generation of the fourth eLectrical output of the storage television camera tube; combining the third and fourth output signals with the first and second output signals; and generating therefrom a processed signal containing position deformation information of the object in its two states.
Claim 37
Independent Claim
329 words
A method for measuring small dimension changes in an object by real time hologram interferometry comprising: illuminating the object in a first state to form a first scattered and reflected object beam; generating a first reference light beam; combining the first object beam with the first reference light beam to form a first interference pattern and projecting the first interference pattern on a storage television camera tube as a visual input; storing the resulting first electrical output of the television tube; generating a second reference light beam having a 90* phase shift with respect to the first light beam; combining the first object beam with the second reference light beam to form a second interference pattern and projecting the second interference pattern on the storage television camera tube as a visual input; storing the resulting second electrical output of the television camera tube; illuminating the object in a second state to form a second scattered and reflected object beam; generating a third reference light beam having a 180* phase shift relative to the first light beam; combining the second object beam with the third reference light beam to form a third interference pattern and projecting the third interference pattern on the storage television camera tube as a visual input; storing the resulting third electrical output of the television camera; generating a fourth reference light beam having a phase shift relative to the first reference light beam of 270*; combining the second scattered and reflected object beam with the fourth reference light beam to form a fourth interference pattern and projecting the fourth interference pattern on the storage television camera tube as a visual input; retrieving the stored first through third electrical outputs in synchronism with the generation of the fourth eLectrical output of the storage television camera tube; combining the third and fourth output signals with the first and second output signals; and generating therefrom a processed signal containing position deformation information of the object in its two states.
Claim 38
Dependent Claim
33 words
A method according to claim 32 wherein the step of combining comprises the step of forming difference signals by subtracting the first and second output signals from the third and fourth output signals.
Claim 39
Dependent Claim
31 words
A method according to claim 33 wherein the step of generating the processed signal comprises the steps of electronically squaring the difference signals and thereafter electronically summing the squared difference signals.
Claim 40
Dependent Claim
15 words
A method according to claim 32 including the step of utilizing the processed output signal.
Claim 41
Dependent Claim
36 words
A method according to claim 35 wherein the step of utilizing comprises the step of forming a display of the object and surface position height information on a cathode ray tube, and visually observing the display.
Claim 42
Dependent Claim
25 words
A method according to claim 35 wherein the step of utilizing comprises the step of driving with the processed signal an automatic object reject-acceptance device.
Claim 43
Dependent Claim
17 words
A method according to claim 32 including the step of transforming the object between the two states.
Claim 44
Dependent Claim
24 words
A method according to claim 38 wherein the transforming step comprises the step of changing the relative stress to which the object is subjected.
Claim 45
Dependent Claim
21 words
A method according to claim 38 wherein the transforming step comprises the step of changing the relative temperature of the object.
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) | 1977-08-05 | 1978-02-04 | 1978-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-05 | 1982-02-04 | 1982-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-05 | 1986-02-04 | 1986-08-06 | $7700.00 | Window Closed / Lapsed |