US3748048A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of detecting changes of a specular surface
Assignee: Motors Liquidation Co
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Filing: 1971-11-01
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Granted: 1973-07-24
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Expires: 1991-11-01
Abstract
Abstract A method of detecting small dimensional surface changes in a specular object or of comparing two nearly identical specular objects comprises illuminating a holographic plate by a plane reference wave and by an object wave produced by specularly reflecting a plane illuminating wave from the object and then illuminating the developed halogram with the conjugate of the reference wave so that the real object image is formed on the object. The light specularly reflected from the object will be a plane wave except to the extent that changes in the object surface have taken place. The nearly planar reflected wave is compared to a plane wave to detect the surface changes. Preferably, the object is originally illuminated by a patterned plane wave so that the final wave reflected from the object during reconstruction can be compared to a negative transparency of the pattern whereby surface changes are readily apparent.
Inventors
- 👤 J Upatnieks
- 👤 A Arbor
- 👤 P Mohan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:31
CPC Classifications
G; G01; G01B; G01B9/00; G01B9/02; G01B9/021; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
125 words
The method of comparing one specular surface with another nearly identical specular surface comprising the steps of illuminating one specular surface with a simple wave of coherent light, constructing a hologram by illuminating a holographic plate with a simple reference wave of coherent light and with light specularly reflected from the surface. developing the hologram, reconstructing the surface image by illuminating the hologram with the conjugate of the reference wave so that the real surface image is directed onto the other surface and reflected therefrom to produce a wave identical to the original surface illuminating wave to the extent the two surfaces are identical, and analyzing the reflected wave to determine its deviation from the original illuminating wave to therefore detect differences in the surface.
Claim 2
Independent Claim
125 words
The method of comparing one specular surface with another nearly identical specular surface comprising the steps of illuminating one specular surface with a simple wave of coherent light, constructing a hologram by illuminating a holographic plate with a simple reference wave of coherent light and with light specularly reflected from the surface. developing the hologram, reconstructing the surface image by illuminating the hologram with the conjugate of the reference wave so that the real surface image is directed onto the other surface and reflected therefrom to produce a wave identical to the original surface illuminating wave to the extent the two surfaces are identical, and analyzing the reflected wave to determine its deviation from the original illuminating wave to therefore detect differences in the surface.
Claim 3
Independent Claim
121 words
The method of detecting surface deformation of a specular object comprising the steps of illuminating a specular object prior to deformation with a plane wave of coherent light, constructing a hologram by illuminating a holographic plate with a plane reference wave of coherent light and with light specularly reflected from the object, developing the hologram, after object deformation reconstructing the object image by illuminating the hologram with the conjugate of the reference wave so that the real object image is directed onto the deformed object and reflected therefrom to produce a wave which is planar to the extent the object surface has not changed since the time of hologram construction, and analyzing the reflected wave to determine its in the object.
Claim 4
Independent Claim
121 words
The method of detecting surface deformation of a specular object comprising the steps of illuminating a specular object prior to deformation with a plane wave of coherent light, constructing a hologram by illuminating a holographic plate with a plane reference wave of coherent light and with light specularly reflected from the object, developing the hologram, after object deformation reconstructing the object image by illuminating the hologram with the conjugate of the reference wave so that the real object image is directed onto the deformed object and reflected therefrom to produce a wave which is planar to the extent the object surface has not changed since the time of hologram construction, and analyzing the reflected wave to determine its in the object.
Claim 5
Independent Claim
146 words
The method of detecting surface deformation of a specular object comprising the steps of superimposing a pattern on a plane wave of coherent light, illuminating a specular object prior to deformation with the plane wave bearing the superimposed pattern, constructing a hologram by illuminating a holographic plate with a plane reference wave of coherent light and with light specularly reflected from the object, developing the hologram, after object deformation reconstructing the object image by illuminating the hologram with the conjugate of the reference wave so that the real object image is directed onto the object and reflected therefrom to produce a resultant patterned wave identical to the original patterned wave to the extent the object surface has not changed since the time of hologram construction, and comparing the pattern carried by the resultant patterned wave with the original pattern to detect surface changes in the object.
Claim 6
Independent Claim
146 words
The method of detecting surface deformation of a specular object comprising the steps of superimposing a pattern on a plane wave of coherent light, illuminating a specular object prior to deformation with the plane wave bearing the superimposed pattern, constructing a hologram by illuminating a holographic plate with a plane reference wave of coherent light and with light specularly reflected from the object, developing the hologram, after object deformation reconstructing the object image by illuminating the hologram with the conjugate of the reference wave so that the real object image is directed onto the object and reflected therefrom to produce a resultant patterned wave identical to the original patterned wave to the extent the object surface has not changed since the time of hologram construction, and comparing the pattern carried by the resultant patterned wave with the original pattern to detect surface changes in the object.
Claim 7
Independent Claim
182 words
The method of detecting surface deformation of a specular object comprising the steps of superimposing a pattern on a plane wave of coherent light, illuminating a specular object prior to deformation with the plane wave bearing the superimposed pattern, constructing a hologram by illuminating a holographic plate with a plane reference wave of coherent light and with light specularly reflected from the object, developing the hologram, after object deformation reconstructing the object image by illuminating the hologram with the conjugate of the reference wave so that the real object image is directed onto the object and reflected therefrom to produce a resultant patterned wave identical to the original patterned wave to the extent the object surface has not changed since the time of hologram construction, and comparing the pattern carried by the resultant patterned wave with the original pattern to detect surface changes in the object by projecting the resultant patterned wave onto a mask bearing a pattern which is the negative of the superimposed pattern so that only portions of the patterned wave corresponding to surface changes pass through the mask.
Claim 8
Independent Claim
182 words
The method of detecting surface deformation of a specular object comprising the steps of superimposing a pattern on a plane wave of coherent light, illuminating a specular object prior to deformation with the plane wave bearing the superimposed pattern, constructing a hologram by illuminating a holographic plate with a plane reference wave of coherent light and with light specularly reflected from the object, developing the hologram, after object deformation reconstructing the object image by illuminating the hologram with the conjugate of the reference wave so that the real object image is directed onto the object and reflected therefrom to produce a resultant patterned wave identical to the original patterned wave to the extent the object surface has not changed since the time of hologram construction, and comparing the pattern carried by the resultant patterned wave with the original pattern to detect surface changes in the object by projecting the resultant patterned wave onto a mask bearing a pattern which is the negative of the superimposed pattern so that only portions of the patterned wave corresponding to surface changes pass through the mask.
References Cited (Backward Citations)
US3619065A
Cited
US3668405A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |