Patent US904687A successfully refreshed from Google Patents.
Patent US5410585A successfully refreshed from Google Patents.
US4620443A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low frequency acoustic microscope
Assignee: Leland Stanford Junior University
•
Filing: 1984-12-13
•
Granted: 1986-11-04
•
Expires: 2004-12-13
Abstract
Abstract A scanning acoustic microscope is disclosed for the detection and location of near surface flaws, inclusions or voids in a solid sample material. A focused beam of acoustic energy is directed at the sample with its focal plane at the subsurface flaw, inclusion or void location. The sample is scanned with the beam. Detected acoustic energy specularly reflected and mode converted at the surface of the sample and acoustic energy reflected by subsurface flaws, inclusions or voids at the focal plane are used for generating an interference signal which is processed and forms a signal indicative of the subsurface flaws, inclusions or voids.
Inventors
- 👤 Butrus T. Khuri-Yakub
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:37
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/04; G01N29/06
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
94 words
The method of detecting and isolating near-surface flaws, inclusions or voids in a solid sample which comprises: directing a focused beam of acoustic energy at the sample with its focal plane at the subsurface flaw, inclusion or void location; scanning the sample with the beam; detecting acoustic energy specularly reflected and mode converted at the surface of the sample and acoustic energy reflected by subsurface flaws, inclusions or voids at the focal plane and generating an interference signal; and processing said signal and forming a signal indicative of the subsurface flaws, inclusions or voids.
Claim 2
Independent Claim
94 words
The method of detecting and isolating near-surface flaws, inclusions or voids in a solid sample which comprises: directing a focused beam of acoustic energy at the sample with its focal plane at the subsurface flaw, inclusion or void location; scanning the sample with the beam; detecting acoustic energy specularly reflected and mode converted at the surface of the sample and acoustic energy reflected by subsurface flaws, inclusions or voids at the focal plane and generating an interference signal; and processing said signal and forming a signal indicative of the subsurface flaws, inclusions or voids.
Claim 3
Dependent Claim
18 words
The method as in claim 1 in which the processing includes detecting the amplitude of the interference signal.
Claim 4
Dependent Claim
16 words
The method as in claim 1 in which the beam is scanned by moving the sample.
Claim 5
Dependent Claim
21 words
The method as in claim 1 including the additional step of forming a display showing the subsurface flaws, inclusions or voids.
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) | 1989-11-03 | 1990-05-05 | 1990-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-03 | 1994-05-05 | 1994-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-03 | 1998-05-05 | 1998-11-04 | $7700.00 | Window Closed / Lapsed |