US4378699A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scanning acoustic microscope
Assignee: National Research Development Corp UK
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Filing: 1980-05-15
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Granted: 1983-04-05
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Expires: 2000-05-15
Abstract
Abstract A scanning acoustic microscope comprises transducer means (10, 12, 14) to provide a convergent beam of acoustic radiation; means (20, 22) to cause relative movement in the focal plane of the focus of the beam and a sample (16); transducer means (10, 12, 14) to receive acoustic radiation modulated by the sample near the beam focus; and means (30) to supply a pressurized gas to a volume surrounding the transducer means and the sample.
Inventors
- 👤 Hemantha K. Wickramasinghe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:52
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/04; G01N29/06; G01N29/0654; G01N29/0681
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
71 words
A scanning acoustic mircoscope comprising: transducer means for providing a convergent beam of acoustic radiation; means for causing relative movement in the focal plane of the focus of said beam and a sample under investigation; transducer means for receiving acoustic radiation modulated by the sample near the beam focus; and means for supplying a gas at higher than atmospheric pressure to a volume between surrounding the transducer means and the sample.
Claim 2
Dependent Claim
71 words
A scanning acoustic mircoscope comprising: transducer means for providing a convergent beam of acoustic radiation; means for causing relative movement in the focal plane of the focus of said beam and a sample under investigation; transducer means for receiving acoustic radiation modulated by the sample near the beam focus; and means for supplying a gas at higher than atmospheric pressure to a volume between surrounding the transducer means and the sample.
Claim 3
Dependent Claim
21 words
A scanning acoustic microscope according to claim 1 in which the gas is at a pressure of at least 10 atmospheres.
Claim 4
Dependent Claim
19 words
A scanning acoustic microscope according to claim 1 or claim 2 in which the gas is a monatomic gas.
Claim 5
Dependent Claim
16 words
A scanning acoustic microscope according to claim 3 in which the gas is argon or xenon.
Claim 6
Dependent Claim
40 words
A scanning acoustic microscope according to claim 1 and operable in a reflection mode in which a transmitting/receiving transducer (10) both provides a convergent beam of acoustic radiation and senses acoustic radiation modulated by the sample near the beam focus.
Claim 7
Dependent Claim
47 words
A scanning acoustic microscope according to claim 5 in which the transmitting/receiving transducer (10) comprises a rod-shaped crystal having at one end a flat face which carries a piezoelectric transducer (12) and at the other end a concave face (14) which carries an impedance matching layer (77).
Claim 8
Dependent Claim
39 words
A scanning acoustic microscope according to claim 6 comprising a sapphire crystal (10) carrying on its concave face (14) an impedance matching layer (77) consisting of a quarter-wave layer of polythylene, the gas being argon at 130 atmospheres pressure.
Claim 9
Dependent Claim
41 words
A scanning acoustic microscope according to claim 6 comprising a sapphire crystal (10) carrying on its concave face (14) an impedance matching layer (77) consisting of successive quarter-wave layers of aluminium, platinum and aluminium, the gas being argon at 250 atmospheres.
Claim 10
Dependent Claim
37 words
A scanning acoustic microscope according to claim 6 comprising a quartz crystal (10) carrying on its concave face (14) an impedance matching layer (77) consisting of a quarter-wave layer of platinum and a quarter-wave layer of aluminium.
Claim 11
Dependent Claim
53 words
A scanning acoustic microscope according to claim 5 in which the transmitting/receiving transducer comprises a crystal (78) of conical form having a concave face (80) at the cone apex and a convex face (82) at the opposite end, the faces being confocal, and a piezoelectric transducer (84) in contact with the convex face.
Claim 12
Dependent Claim
98 words
A scanning acoustic mircoscope system comprising a scanning acoustic microscope according to claim 1 and further comprising circuit means (74, 76) for providing an exciting signal to the transducer means which provides a convergent beam of acoustic radiation, for receiving an information signal from the transducer means which senses acoustic radiation modulated by the sample near the beam focus, for decoding the information signal, and for supplying a signal to a visual display unit; and means (66, 68, 70) for causing relative movement between the focal plane and the sample in a direction transverse to the focal plane.
Claim 13
Dependent Claim
23 words
A scanning acoustic microscope according to any one of claims 1 through 11 in which the pressurised gas is an approximately ideal gas.
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) | 1986-04-04 | 1986-10-04 | 1987-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-04 | 1990-10-04 | 1991-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-04 | 1994-10-04 | 1995-04-05 | $7700.00 | Window Closed / Lapsed |