US4781455A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for measuring optical strain and apparatus therefor
Assignee: Carl Zeiss AG
•
Filing: 1986-05-08
•
Granted: 1988-11-01
•
Expires: 2006-05-08
Abstract
Abstract A method and an apparatus for optical strain measurement are disclosed. Prior to the deformation or loading of the object to be tested, the latter is provided with a thin transparent film which adheres well to the object and has a thickness between 3 and 20 μm. After the deformation or during loading, the wavelength-dependent intensity course developed because of the interference of the portion of the beam of light reflected and superimposed at the boundary surfaces of the transparent film is measured and evaluated by a computer.
Inventors
- 👤 Meinrad Machler
- 👤 Harry Schlemmer
- 👤 Ursula Rager
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:56
CPC Classifications
G; G01; G01L; G01L1/00; G01L1/24; G01B; G01B11/00; G01B11/16; G01B11/18
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
144 words
A method for optically measuring strain in transparent and opaque objects comprising the steps of: placing a transparent film upon the object to define boundary layers and to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; directing a bundle of optical rays onto said film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby a wavelength-dependent intensity course develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said transparent film; and, measuring and evaluating said intensity course.
Claim 2
Independent Claim
144 words
A method for optically measuring strain in transparent and opaque objects comprising the steps of: placing a transparent film upon the object to define boundary layers and to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; directing a bundle of optical rays onto said film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby a wavelength-dependent intensity course develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said transparent film; and, measuring and evaluating said intensity course.
Claim 3
Dependent Claim
19 words
The method of claim 1, said transparent film having a thickness in the range of 3 to 20 μm.
Claim 4
Independent Claim
167 words
A method for optically measuring strain in transparent and opaque objects comprising the steps of: placing a transparent film upon the object to define boundary layers and to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; said transparent film being made of a metal protecting lacquer, and said lacquer being applied to said object by spraying the same thereon; directing a bundle of optical rays onto said film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby a wavelength-dependent intensity course develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said transparent film; and, measuring and evaluating said intensity course.
Claim 5
Independent Claim
167 words
A method for optically measuring strain in transparent and opaque objects comprising the steps of: placing a transparent film upon the object to define boundary layers and to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; said transparent film being made of a metal protecting lacquer, and said lacquer being applied to said object by spraying the same thereon; directing a bundle of optical rays onto said film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby a wavelength-dependent intensity course develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said transparent film; and, measuring and evaluating said intensity course.
Claim 6
Independent Claim
173 words
A method for optically measuring strain in transparent and opaque objects comprising the steps of: placing a transparent film upon the object to define boundary layers and to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; said transparent film being made of a metal protecting lacquer, and said lacquer being applied by dipping said object into the same and allowing excess lacquer to drip therefrom; directing a bundle of optical rays onto said film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby a wavelength-dependent intensity course develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said transparent film; and, measuring and evaluating said intensity course.
Claim 7
Independent Claim
173 words
A method for optically measuring strain in transparent and opaque objects comprising the steps of: placing a transparent film upon the object to define boundary layers and to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; said transparent film being made of a metal protecting lacquer, and said lacquer being applied by dipping said object into the same and allowing excess lacquer to drip therefrom; directing a bundle of optical rays onto said film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby a wavelength-dependent intensity course develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said transparent film; and, measuring and evaluating said intensity course.
Claim 8
Dependent Claim
19 words
The method of claim 1, said transparent layer being a foil which is held on said object by adhesive.
Claim 9
Dependent Claim
17 words
The method of claim 1, said transparent layer being a foil which is melted onto said object.
Claim 10
Independent Claim
172 words
An apparatus for optically measuring strain in transparent and opaque objects comprising: a transparent film formed on said object so as to define boundary layers and to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; optical ray source means arranged so as to be adjacent said transparent film for supplying and directing a bundle of optical rays of continuously adjustable wavelength onto said transparent film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby an intensity develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said film; and, measuring means for measuring said intensity to obtain a measurement of the strain present in said object.
Claim 11
Independent Claim
172 words
An apparatus for optically measuring strain in transparent and opaque objects comprising: a transparent film formed on said object so as to define boundary layers and to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; optical ray source means arranged so as to be adjacent said transparent film for supplying and directing a bundle of optical rays of continuously adjustable wavelength onto said transparent film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby an intensity develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said film; and, measuring means for measuring said intensity to obtain a measurement of the strain present in said object.
Claim 12
Dependent Claim
77 words
The apparatus of claim 7, comprising: a Y-shaped light conductor having a common trunk and two branches extending from said trunk, said optical ray source means being connected to one of said branches; said measuring means including receiver means connected to said other one of said branches for measuring the rays of said component beam; and, measuring head means connected to said trunk for directing said bundle of optical rays onto said film in a predetermined manner.
Claim 13
Dependent Claim
12 words
The apparatus of claim 8, said receiver means comprising a diode-array spectrometer.
Claim 14
Dependent Claim
22 words
The apparatus of claim 8, comprising computer means connected to said receiver means for evaluating the measurements made in said measuring means.
Claim 15
Dependent Claim
48 words
The apparatus of claim 10, said measuring head means comprising a mechanical scanning arrangement operatively connected to said computer means so as to be controllable by the latter; and, said computer means being programmed for making a position-dependent measurement and display of the mechanical strain in said object.
Claim 16
Dependent Claim
25 words
The apparatus of claim 11, said mechanical scanning arrangement being adapted for movement in three spatial coordinates and for tilting about two mutually perpendicular angles.
Claim 17
Dependent Claim
19 words
The apparatus of claim 7, said transparent film having a thickness in the range of 3 to 20 μm.
Claim 18
Independent Claim
175 words
An apparatus for optically measuring strain in transparent and opaque objects comprising: a transparent film formed on said object so as to define boundary layers and to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; said transparent film being made of a metal protecting lacquer, and said lacquer being applied to said object by spraying the same thereon; optical ray source means for supplying and directing a bundle of optical rays of continuously adjustable wavelength onto said transparent film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby an intensity develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said film; and, measuring means for measuring said intensity.
Claim 19
Independent Claim
175 words
An apparatus for optically measuring strain in transparent and opaque objects comprising: a transparent film formed on said object so as to define boundary layers and to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; said transparent film being made of a metal protecting lacquer, and said lacquer being applied to said object by spraying the same thereon; optical ray source means for supplying and directing a bundle of optical rays of continuously adjustable wavelength onto said transparent film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby an intensity develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said film; and, measuring means for measuring said intensity.
Claim 20
Independent Claim
181 words
An apparatus for optically measuring strain in transparent and opaque objects comprising: a transparent film formed on said object so as to define boundary layers and to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; said transparent film being made of a metal protecting lacquer, and said lacquer being applied by dipping said object into the same and allowing excess lacquer to drip therefrom; optical ray source means for supplying and directing a bundle of optical rays of continuously adjustable wavelength onto said transparent film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby an intensity develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said film; and, measuring means for measuring said intensity.
Claim 21
Independent Claim
181 words
An apparatus for optically measuring strain in transparent and opaque objects comprising: a transparent film formed on said object so as to define boundary layers and to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; said transparent film being made of a metal protecting lacquer, and said lacquer being applied by dipping said object into the same and allowing excess lacquer to drip therefrom; optical ray source means for supplying and directing a bundle of optical rays of continuously adjustable wavelength onto said transparent film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby an intensity develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said film; and, measuring means for measuring said intensity.
Claim 22
Dependent Claim
19 words
The apparatus of claim 7, said transparent layer being a foil which is held on said object by adhesive.
Claim 23
Dependent Claim
17 words
The apparatus of claim 7, said transparent layer being a foil which is melted onto said object.
Claim 24
Independent Claim
176 words
An apparatus for optically measuring strain in transparent and opaque objects comprising: a transparent film formed on said object so as to define boundary layers, said film being selected so as to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; continuous radiation source means arranged so as to be adjacent said transparent film for supplying and directing a bundle of optical rays onto said transparent film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby a wavelength-dependent intensity course develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said film; and, measuring means for measuring said intensity course to obtain a measurement of the strain present in said object.
Claim 25
Independent Claim
176 words
An apparatus for optically measuring strain in transparent and opaque objects comprising: a transparent film formed on said object so as to define boundary layers, said film being selected so as to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; continuous radiation source means arranged so as to be adjacent said transparent film for supplying and directing a bundle of optical rays onto said transparent film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby a wavelength-dependent intensity course develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said film; and, measuring means for measuring said intensity course to obtain a measurement of the strain present in said object.
Claim 26
Dependent Claim
77 words
The apparatus of claim 18, comprising: a Y-shaped light conductor having a common trunk and two branches extending from said trunk, said continuous radiation source means being connected to one of said branches; said measuring means including receiver means connected to said other one of said branches for measuring the rays of said component beam; and, measuring head means connected to said trunk for directing said bundles of optical rays onto said fibers in a predetermined manner.
Claim 27
Dependent Claim
12 words
The apparatus of claim 19, said receiver means comprising a diode-array spectrometer.
Claim 28
Dependent Claim
22 words
The apparatus of claim 19, comprising computer means connected to said receiver means for evaluating the measurements made in said measuring means.
Claim 29
Dependent Claim
48 words
The apparatus of claim 21, said measuring head means comprising a mechanical scanning arrangement operatively connected to said computer means so as to be controllable by the latter; and, said computer means being programmed for making a position-dependent measurement and display of the mechanical strain in said object.
Claim 30
Dependent Claim
25 words
The apparatus of claim 22, said mechanical scanning arrangement being adapted for movement in three spatial coordinates and for tilting about two mutually perpendicular angles.
Claim 31
Dependent Claim
19 words
The apparatus of claim 18, said transparent film having a thickness in the range of 3 to 20 μm.
Claim 32
Independent Claim
179 words
An apparatus for optically measuring strain in transparent and opaque objects comprising: a transparent film formed on said object so as to define boundary layers, said film being selected so as to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; said transparent film being made of a metal protecting lacquer, and said lacquer being applied to said object by spraying the same thereon; continuous radiation source means for supplying and directing a bundle of optical rays onto said transparent film so as to cause a portion of said rays to be reflected therefrom and defined a component beam whereby a wavelength-dependent intensity course develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said film; and, measuring means for measuring said intensity course.
Claim 33
Independent Claim
179 words
An apparatus for optically measuring strain in transparent and opaque objects comprising: a transparent film formed on said object so as to define boundary layers, said film being selected so as to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; said transparent film being made of a metal protecting lacquer, and said lacquer being applied to said object by spraying the same thereon; continuous radiation source means for supplying and directing a bundle of optical rays onto said transparent film so as to cause a portion of said rays to be reflected therefrom and defined a component beam whereby a wavelength-dependent intensity course develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said film; and, measuring means for measuring said intensity course.
Claim 34
Independent Claim
185 words
An apparatus for optically measuring strain in transparent and opaque objects comprising: a transparent film formed on said object so as to define boundary layers, said film being selected so as to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermine value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; said transparent film being made of a metal protecting lacquer, and said lacquer being applied by dipping said object into the same and allowing excess lacquer to drip therefrom; continuous radiation source means for supplying and directing a bundle of optical rays onto said transparent film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby a wavelength-dependent intensity course develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said film; and, measuring means for measuring said intensity course.
Claim 35
Independent Claim
185 words
An apparatus for optically measuring strain in transparent and opaque objects comprising: a transparent film formed on said object so as to define boundary layers, said film being selected so as to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermine value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; said transparent film being made of a metal protecting lacquer, and said lacquer being applied by dipping said object into the same and allowing excess lacquer to drip therefrom; continuous radiation source means for supplying and directing a bundle of optical rays onto said transparent film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby a wavelength-dependent intensity course develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said film; and, measuring means for measuring said intensity course.
Claim 36
Dependent Claim
19 words
The apparatus of claim 18, said transparent layer being a foil which is held onto said object by adhesive.
Claim 37
Dependent Claim
17 words
The apparatus of claim 18, said transparent layer being a foil which is melted onto said object.
Claim 38
Dependent Claim
27 words
The apparatus of claim 21, comprising adjusting means for continuously adjusting the wavelength of said optical rays; and, said computer means being connected to said adjusting means.
Claim 39
Independent Claim
218 words
An apparatus for optically measuring strain in transparent and opaque objects comprising: a transparent film formed on said object so as to define boundary layers and to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; optical ray source means for supplying and directing a bundle of optical rays of continuously adjustable wavelength onto said transparent film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby an intensity develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said film; light conducting means for conducting said component beam away from said transparent film; polarizer means rotatably mounted between said film and said light conducting means; receiver means for receiving said component beam and measuring the wavelength-dependent course of the intensity arising from the interference of the light of said component beam; and, computer means connected to said receiver means for processing the output of the latter to compute the strain in said object.
Claim 40
Independent Claim
218 words
An apparatus for optically measuring strain in transparent and opaque objects comprising: a transparent film formed on said object so as to define boundary layers and to adhere well to said object to ensure that the strains on the surface of the latter are transmitted to said film; said film having a thickness selected so as to be less than a predetermined value below which the formation of strain gradients in said film in the direction of the film thickness are precluded; optical ray source means for supplying and directing a bundle of optical rays of continuously adjustable wavelength onto said transparent film so as to cause a portion of said rays to be reflected therefrom and define a component beam whereby an intensity develops because of the interference of said component beam which is superposed and reflected at said boundary layers of said film; light conducting means for conducting said component beam away from said transparent film; polarizer means rotatably mounted between said film and said light conducting means; receiver means for receiving said component beam and measuring the wavelength-dependent course of the intensity arising from the interference of the light of said component beam; and, computer means connected to said receiver means for processing the output of the latter to compute the strain in said 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) | 1991-11-01 | 1992-05-02 | 1992-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-01 | 1996-05-02 | 1996-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-01 | 2000-05-02 | 2000-11-01 | $7700.00 | Window Closed / Lapsed |