Patent US4366380A successfully refreshed from Google Patents.
US4366380A
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Method and apparatus for structural analysis
Assignee: Individual
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Filing: 1981-03-12
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Granted: 1982-12-28
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Expires: 2001-03-12
Abstract
Abstract Apparatus for the non-destructive structural analysis of a solid object, the apparatus comprising: a laser pulse generating device to generate a laser beam pulse at a selected frequency for application to an input surface of an object to be analyzed to generate an elastic wave pattern in the object; a scanning electron microscope for scanning at a frequency which is a multiple of the laser beam pulse frequency, the generated wave pattern over an output surface of the object to provide an output signal; a control device for controlling operation of the scanning electron microscope in relation to the laser beam pulse to progressively vary the phase difference between the scanning frequency and the laser beam pulse frequency, and a processing device for processing such an output signal to allow generation of a representative signal representative of such a wave pattern at a preselected time instant; generating means for generating a composite signal from such a representative signal and from a reference signal derived from the laser pulse frequency; and a digital computer for processing such a composite signal to provide reconstruction means in the form of a digital hologram for reconstructing a representation of the object. The invention further extends to a corresponding method.
Inventors
- 👤 George Mirkin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:22
CPC Classifications
G; G03; G03H; G03H3/00; G01; G01N; G01N29/00; G01N29/22; G01N29/24; G01N29/2418; G01N2291/00; G01N2291/04; G01N2291/042; G01N2291/0426
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
147 words
A method for the non-destructive structural analysis of a solid object, the method comprising: applying a wave-generating laser beam pulse at a selected frequency to an input surface of the object to generate an elastic wave pattern in the object; scanning the generated wave pattern over an output surface of the object with an electron beam scanning device in an evacuated chamber at a frequency which is a multiple of the wave-generating pulse frequency, to provide an output signal; controlling operation of the scanning device in relation to the wave-generating pulse and processing the output signal to generate a representative signal representative of the wave pattern at a preselected time instant; generaing a composite signal from the representative signal and from a reference signal related to the wave-generating pulse; and processing the composite signal to provide reconstruction means for the reconstruction of a representation of the object.
Claim 2
Independent Claim
147 words
A method for the non-destructive structural analysis of a solid object, the method comprising: applying a wave-generating laser beam pulse at a selected frequency to an input surface of the object to generate an elastic wave pattern in the object; scanning the generated wave pattern over an output surface of the object with an electron beam scanning device in an evacuated chamber at a frequency which is a multiple of the wave-generating pulse frequency, to provide an output signal; controlling operation of the scanning device in relation to the wave-generating pulse and processing the output signal to generate a representative signal representative of the wave pattern at a preselected time instant; generaing a composite signal from the representative signal and from a reference signal related to the wave-generating pulse; and processing the composite signal to provide reconstruction means for the reconstruction of a representation of the object.
Claim 3
Dependent Claim
47 words
A method according to claim 1, in which the representative signal is generated by progressively varying the phase difference between the scanning frequency and the wave-generating pulse frequency, and by periodically processing the output signal at a constant time interval in relation to the wave-generating pulse frequency.
Claim 4
Dependent Claim
30 words
A method according to claim 1 or claim 2, in which the composite signal is processed to provide reconstruction means in the form of an optical hologram of the object.
Claim 5
Dependent Claim
36 words
A method according to claim 1 or claim 2, in which the composite signal is processed by means of a computer programmed to provide reconstruction means in the form of a computer hologram of the object.
Claim 6
Dependent Claim
20 words
A method according to claim 4, in which the computer is programmed to provide a digital hologram of the object.
Claim 7
Dependent Claim
27 words
A method according to claim 5, in which a display module is associated with the computer to provide a holograph of the object from the digital hologram.
Claim 8
Dependent Claim
35 words
A method according to claim 1 or claim 2, which includes the step of coating the output surface of the object with a coating layer to reduce interference resulting from imperfections in the output surface.
Claim 9
Dependent Claim
25 words
A method according to claim 7, in which the output surface is coated with a material selected from the group consisting of metals and semi-metals.
Claim 10
Dependent Claim
45 words
A method according to claim 1 or claim 2, which includes the step of associating an electrostatic layer with the output surface, the electrostatic layer being capable of responding electrostatically to the wave pattern to facilitate sensing of the wave pattern by the scanning device.
Claim 11
Dependent Claim
28 words
A method according to claim 1 or claim 2, in which the scanning device is in the form of a scanning electron microscope housed within an evacuation chamber.
Claim 12
Dependent Claim
15 words
A method according to claim 10, in which the object is sealed within the chamber.
Claim 13
Dependent Claim
34 words
A method according to claim 11, in which the laser beam pulse is transmitted to the input surface by means of a beam conducting fibre which passes sealingly through a wall defining the chamber.
Claim 14
Dependent Claim
179 words
Apparatus for the non-destructive structural analysis of a solid object, the apparatus comprising: a laser pulse generating device to generate a laser beam pulse at a selected frequency for application to an input surface of an object to be analysed to generate an elastic wave pattern in the object; an electron beam scanning device for scanning in an evacuated chamber at a frequency which is a multiple of a generated pulse frequency, a generated wave pattern over an output surface of such an object to provide an output signal; a control device for controlling operation of the the scanning device in relation to the pulse generating device, and a processing device for processing such an output signal to allow generation of a representative signal representative of such a wave pattern at a preselected time instant; generating means for generating a composite signal from such a representative signal and from a reference signal related to a generated pulse frequency; and processing means for processing such a composite signal to provide reconstruction means for reconstructing a representation of such an object.
Claim 15
Dependent Claim
179 words
Apparatus for the non-destructive structural analysis of a solid object, the apparatus comprising: a laser pulse generating device to generate a laser beam pulse at a selected frequency for application to an input surface of an object to be analysed to generate an elastic wave pattern in the object; an electron beam scanning device for scanning in an evacuated chamber at a frequency which is a multiple of a generated pulse frequency, a generated wave pattern over an output surface of such an object to provide an output signal; a control device for controlling operation of the the scanning device in relation to the pulse generating device, and a processing device for processing such an output signal to allow generation of a representative signal representative of such a wave pattern at a preselected time instant; generating means for generating a composite signal from such a representative signal and from a reference signal related to a generated pulse frequency; and processing means for processing such a composite signal to provide reconstruction means for reconstructing a representation of such an object.
Claim 16
Dependent Claim
71 words
Apparatus according to claim 13, in which the control device is adapted to control operation of the scanning device in relation to the pulse generating device by progressively varying the phase difference between the scanning frequency and the pulse frequency, and in which the processing device is adapted to generate a representative signal by processing such an output signal periodically at a constant time interval in relation to the pulse frequency.
Claim 17
Dependent Claim
28 words
Apparatus according to claim 13 or claim 14, in which the processing means comprises optical processing means to provide reconstruction means in the form of an optical hologram.
Claim 18
Dependent Claim
28 words
Apparatus according to claim 13 or claim 14, in which the processing means comprises a computer programmed to provide reconstruction means in the form of a computer hologram.
Claim 19
Dependent Claim
16 words
Apparatus according to claim 16, in which the computer is programmed to provide a digital hologram.
Claim 20
Dependent Claim
17 words
Apparatus according to claim 17, including a display module to provide a holograph from the digital hologram.
Claim 21
Dependent Claim
27 words
Apparatus according to claim 13 or claim 14, in which the scanning device is in the form of a scanning electron microscope housed within an evacuation chamber.
Claim 22
Dependent Claim
24 words
Apparatus according to claim 19, in which the evacuation chamber includes a support for supporting an object to be analysed within the evacuation chamber.
Claim 23
Dependent Claim
30 words
Apparatus according to claim 20, in which the apparatus includes a beam conducting fibre which extends sealingly through a wall defining the evacuation chamber, and which extends to the support.
References Cited (Backward Citations)
US3745812A
Cited
US4109966A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-27 | 1986-06-28 | 1986-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-27 | 1990-06-28 | 1990-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-27 | 1994-06-28 | 1994-12-28 | $7700.00 | Window Closed / Lapsed |