US4619529A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interferometric contact-free measuring method for sensing motional surface deformation of workpiece subjected to ultrasonic wave vibration
Assignee: Nippon Steel Corp
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Filing: 1983-01-04
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Granted: 1986-10-28
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Expires: 2003-01-04
Abstract
Abstract An interferometric contact-free measuring method for sensing, by a laser beam, motional surface deformation of a workpiece subject to an ultrasonic vibration, comprising splitting the laser beam into a measuring beam incident upon a measuring point on the workpiece and a reference beam incident upon a reference point close to the measuring point, and bringing the two beams, after reflection, into a common optical detector.
Inventors
- 👤 Tohru Iuchi
- 👤 Fumio Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:08
CPC Classifications
G; G01; G01H; G01H9/00; G01N; G01N29/00; G01N29/22; G01N29/24; G01N29/2418; G01N2291/00; G01N2291/02; G01N2291/028; G01N2291/02854; G01N2291/04; G01N2291/042; G01N2291/0421
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
168 words
In interferometric contact-free measuring method for sensing motional surface deformation of a workpiece subject to ultrasonic vibration comprising the steps of: impinging a first pulse laser beam on a surface of the workpiece to induce an ultrasonic wave in the workpiece, longitudinal ultrasonic pulses induced in a thickness of the workpiece generating echoes, generating a second laser beam, splitting the second laser beam into a measuring beam and a reference beam, causing the measuring beam to impinge upon the measuring point on the workpiece surface, causing the reference beam to impinge upon a reference beam point on the workpiece surface separate and distinct from the measuring point, the distance between the measuring and reference points being such that an echo of a second pulse of said laser beam reaches the measuring point before a first pulse reaches the reference point, and causing the measuring and reference beams reflected from the workpiece surface at the measuring point and the reference point, respectively, to impinge upon the same optical detector.
Claim 2
Dependent Claim
168 words
In interferometric contact-free measuring method for sensing motional surface deformation of a workpiece subject to ultrasonic vibration comprising the steps of: impinging a first pulse laser beam on a surface of the workpiece to induce an ultrasonic wave in the workpiece, longitudinal ultrasonic pulses induced in a thickness of the workpiece generating echoes, generating a second laser beam, splitting the second laser beam into a measuring beam and a reference beam, causing the measuring beam to impinge upon the measuring point on the workpiece surface, causing the reference beam to impinge upon a reference beam point on the workpiece surface separate and distinct from the measuring point, the distance between the measuring and reference points being such that an echo of a second pulse of said laser beam reaches the measuring point before a first pulse reaches the reference point, and causing the measuring and reference beams reflected from the workpiece surface at the measuring point and the reference point, respectively, to impinge upon the same optical detector.
Claim 3
Dependent Claim
32 words
A method according to claim 1 wherein the step of causing the reference beam to impinge comprises the step of reflecting the reference beam toward the reference point on the workpiece surface.
Claim 4
Dependent Claim
19 words
A method according to claim 1, further comprising the step of modulating at least one of the split beams.
Claim 5
Dependent Claim
54 words
A method according to claim 1 wherein the step of causing the reflected measuring and reference beams to impinge on the same optical detector comprises the step of combining the measuring beam and the reference beam reflected from the measuring point and the reference point, respectively, to bring them into the common optical detector.
Claim 6
Dependent Claim
103 words
An interferometric contact-free measuring method for sensing motional surface deformation of a workpiece caused by a longitudinal wave applied thereto comprising the steps of: generating the laser beam, splitting the laser beam into a measuring beam and a reference beam, causing the measuring beam to impinge upon a measuring point on the workpiece surface, causing the reference beam to impinge upon a reference point on the workpiece surface separate and distinct from the measuring point, and causing the measuring and reference beams reflected from the workpiece surface at the measuring point and the reference point, respectively, to impinge upon the same optical detector.
Claim 7
Dependent Claim
103 words
An interferometric contact-free measuring method for sensing motional surface deformation of a workpiece caused by a longitudinal wave applied thereto comprising the steps of: generating the laser beam, splitting the laser beam into a measuring beam and a reference beam, causing the measuring beam to impinge upon a measuring point on the workpiece surface, causing the reference beam to impinge upon a reference point on the workpiece surface separate and distinct from the measuring point, and causing the measuring and reference beams reflected from the workpiece surface at the measuring point and the reference point, respectively, to impinge upon the same optical detector.
Claim 8
Dependent Claim
121 words
An interferometric contact-free measuring method for sensing motional surface deformation of a workpiece caused by an ultrasonic wave comprising the steps of: generating the laser beam, splitting the laser beam into a measuring beam and a reference beam, causing the measuring beam to impinge upon a measuring point on a workpiece surface, causing the reference beam to impinge upon a reference point on the workpiece surface separate and distinct from the measuring point, causing the measuring and reference beams reflected from the workpiece surface at the measuring point and the reference point, respectively, to impinge upon the same optical detector, and temporarily increasing the magnitude of the measuring beam only when the ultrasonic wave to be detected exists in the workpiece.
Claim 9
Dependent Claim
121 words
An interferometric contact-free measuring method for sensing motional surface deformation of a workpiece caused by an ultrasonic wave comprising the steps of: generating the laser beam, splitting the laser beam into a measuring beam and a reference beam, causing the measuring beam to impinge upon a measuring point on a workpiece surface, causing the reference beam to impinge upon a reference point on the workpiece surface separate and distinct from the measuring point, causing the measuring and reference beams reflected from the workpiece surface at the measuring point and the reference point, respectively, to impinge upon the same optical detector, and temporarily increasing the magnitude of the measuring beam only when the ultrasonic wave to be detected exists in the workpiece.
Claim 10
Dependent Claim
138 words
An interferometric contact-free measuring method for sensing motional surface deformation of a workpiece caused by a laser beam applied to a measuring point on the workpiece surface and inducing an ultrasonic wave therein comprising the steps of: impinging a first pulse laser beam on a surface of the workpiece to induce an ultrasonic wave in the workpiece, generating a second laser beam, splitting the second laser beam into a measuring beam and a reference beam, causing the measuring beam to impinge upon the measuring point on the workpiece surface, causing the reference beam to impinge upon a reference beam point on the workpiece surface separate and distinct from the measuring point, and causing measuring and reference beams reflected from the workpiece surface at the measuring point and the reference point, respectively, to impinge upon the same optical detector.
Claim 11
Dependent Claim
138 words
An interferometric contact-free measuring method for sensing motional surface deformation of a workpiece caused by a laser beam applied to a measuring point on the workpiece surface and inducing an ultrasonic wave therein comprising the steps of: impinging a first pulse laser beam on a surface of the workpiece to induce an ultrasonic wave in the workpiece, generating a second laser beam, splitting the second laser beam into a measuring beam and a reference beam, causing the measuring beam to impinge upon the measuring point on the workpiece surface, causing the reference beam to impinge upon a reference beam point on the workpiece surface separate and distinct from the measuring point, and causing measuring and reference beams reflected from the workpiece surface at the measuring point and the reference point, respectively, to impinge upon the same optical detector.
Claim 12
Dependent Claim
22 words
A method according to claim 7, wherein the motional surface deformation of the workpiece is caused by a surface wave applied thereto.
Claim 13
Dependent Claim
22 words
A method according to claim 7, wherein the motional surface deformation of the workpiece is caused by a transversal wave applied thereto.
Claim 14
Dependent Claim
137 words
An interferometric contact-free measuring method for sensing motional surface deformation of a workpiece caused by a laser beam applied to a point opposite to a measuring point on the workpiece surface, comprising the steps of: impinging a first pulse laser beam on a surface of the workpiece to induce an ultrasonic wave in the workpiece, generating a second laser beam, splitting the second laser beam into a measuring beam and a reference beam, causing the measuring beam to impinge upon the measuring point on the workpiece surface, causing the reference beam to impinge upon a reference beam point on the workpiece surface separate and distinct from the measuring point, and causing the measuring and reference beams reflected from the workpiece surface at the measuring point and the reference point, respectively, to impinge upon the same optical detector.
Claim 15
Dependent Claim
137 words
An interferometric contact-free measuring method for sensing motional surface deformation of a workpiece caused by a laser beam applied to a point opposite to a measuring point on the workpiece surface, comprising the steps of: impinging a first pulse laser beam on a surface of the workpiece to induce an ultrasonic wave in the workpiece, generating a second laser beam, splitting the second laser beam into a measuring beam and a reference beam, causing the measuring beam to impinge upon the measuring point on the workpiece surface, causing the reference beam to impinge upon a reference beam point on the workpiece surface separate and distinct from the measuring point, and causing the measuring and reference beams reflected from the workpiece surface at the measuring point and the reference point, respectively, to impinge upon the same optical detector.
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