Patent US4334253A successfully refreshed from Google Patents.
Patent US4179936A successfully refreshed from Google Patents.
US4179936A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic image recorders
Assignee: National Research Development Corp UK
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Filing: 1978-05-18
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Granted: 1979-12-25
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Expires: 1998-05-18
Abstract
Abstract A method of sensing changes in an object comprising irradiating the object with a focused beam of acoustic radiation excited by a first alternating electric signal; receiving a beam of acoustic radiation modulated in phase and amplitude by the object in the vicinity of the focus and deriving a second alternating electric signal therefrom; providing a reference electric signal derived from the first alternating electric signal and at a known phase; mixing coherently the second signal and the reference signal to derive a first in-phase signal; mixing the second signal with the reference signal altered in phase by between 80° and 100° to provide a first quadrature signal; storing the first in-phase and first quadrature signals; after an interval of time receiving a beam of acoustic radiation modulated by the same part of the object and deriving a third alternating electric signal therefrom and similarly deriving second in-phase and second quadrature signals; and combining the stored first and the second signals so as to sense any change in the object.
Inventors
- 👤 Simon D. Bennett
- 👤 Eric A. Ash
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:18
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/04; G01N29/06; G01H; G01H3/00; G01H3/10; G01H3/12; G01H3/125; G01S; G01S15/00; G01S15/88; G01S15/89; G01S15/8906; G01S15/8965; G01S15/8968
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
170 words
A method of sensing changes in an object comprising irradiating the object with a focused beam of acoustic radiation excited by a first alternating electric signal; receiving a beam of acoustic radiation modulated in phase and amplitude by the object in the vicinity of the focus and deriving a second alternating electric signal therefrom; providing a reference electric signal derived from the first alternating electric signal and at a known phase; mixing coherently the second signal and the reference signal to derive a first in-phase signal; mixing the second signal with the reference signal altered in phase by between 80° and 100° to provide a first quadrature signal; storing the first in-phase and first quadrature signals; after an interval of time receiving a beam of acoustic radiation modulated by the same part of the object and deriving a third alternating electric signal therefrom and similarly deriving second in-phase and second quadrature signals; and combining the stored first and the second signals so as to sense any change in the object.
Claim 2
Independent Claim
170 words
A method of sensing changes in an object comprising irradiating the object with a focused beam of acoustic radiation excited by a first alternating electric signal; receiving a beam of acoustic radiation modulated in phase and amplitude by the object in the vicinity of the focus and deriving a second alternating electric signal therefrom; providing a reference electric signal derived from the first alternating electric signal and at a known phase; mixing coherently the second signal and the reference signal to derive a first in-phase signal; mixing the second signal with the reference signal altered in phase by between 80° and 100° to provide a first quadrature signal; storing the first in-phase and first quadrature signals; after an interval of time receiving a beam of acoustic radiation modulated by the same part of the object and deriving a third alternating electric signal therefrom and similarly deriving second in-phase and second quadrature signals; and combining the stored first and the second signals so as to sense any change in the object.
Claim 3
Dependent Claim
18 words
A method according to claim 1 in which the beam of acoustic radiation is transmitted through the object.
Claim 4
Dependent Claim
18 words
A method according to claim 1 in which the beam of acoustic radiation is reflected by the object.
Claim 5
Dependent Claim
84 words
A method according to claim 1 further comprising causing relative movement in the focal plane of the object and the focus of the acoustic beam; deriving a first in-phase and a first quadrature signal at each of a plurality of relative positions; storing each first in-phase and first quadrature signal; after said interval of time repeating the movement and deriving a second in-phase and a second quadrature signal at each said position; and combining for each position the stored first and the second signals.
Claim 6
Dependent Claim
121 words
Apparatus for use in sensing a change in an object comprising means for irradiating the object with a focused beam of acoustic radiation excited by a first alternating electric signal; means for receiving a beam of acoustic radiation modulated in phase and amplitude by the object in the vicinity of the focus and for deriving a second alternating electric signal therefrom; means for providing a reference electric signal derived from the first alternating electric signal and at a known phase; and mixing means for mixing coherently the second signal and the reference signal to derive an in-phase signal and for mixing the second signal and the reference signal altered in phase by between 80° and 100° to derive a quadrature signal.
Claim 7
Dependent Claim
121 words
Apparatus for use in sensing a change in an object comprising means for irradiating the object with a focused beam of acoustic radiation excited by a first alternating electric signal; means for receiving a beam of acoustic radiation modulated in phase and amplitude by the object in the vicinity of the focus and for deriving a second alternating electric signal therefrom; means for providing a reference electric signal derived from the first alternating electric signal and at a known phase; and mixing means for mixing coherently the second signal and the reference signal to derive an in-phase signal and for mixing the second signal and the reference signal altered in phase by between 80° and 100° to derive a quadrature signal.
Claim 8
Dependent Claim
75 words
Apparatus according to claim 5 further comprising scanning means arranged to cause relative movement in the focal plane of the object and the focus of the acoustic beam; storage means connected to the mixing means to store an in-phase signal and a quadrature signal corresponding to each of a plurality of relative positions of the object; and combination means for combining for each position of the object the stored signals with the successively provided signals.
Claim 9
Dependent Claim
37 words
Apparatus according to claim 6 in which the scanning means moves the object stepwise in the focal plane in a repeatable pattern; and at each step in the movement an in-phase and a quadrature signal are derived.
Claim 10
Dependent Claim
186 words
Apparatus for sensing changes in an object comprising: means for irradiating the object with a focused beam of acoustic radiation excited by a first alternating electric signal; means for receiving a beam of acoustic radiation modulated in phase and amplitude by the object in the vicinity of the focus and deriving a second alternating electric signal therefrom; means for providing a reference electric signal derived from the first alternating electric signal and at a known phase; means for mixing coherently the second signal and the reference signal to derive a first in-phase signal; means for mixing the second signal with the reference signal altered in phase by between 80° and 100° to provide a first quadrature signal; means for storing the first in-phase and first quadrature signals; means operative after an interval of time for receiving a beam of acoustic radiation modulated by the same part of the object and deriving a third alternating electric signal therefrom and similarly deriving second in-phase and second quadrature signals; and means for combining the stored first and the second signals so as to sense any change in the object.
Claim 11
Dependent Claim
186 words
Apparatus for sensing changes in an object comprising: means for irradiating the object with a focused beam of acoustic radiation excited by a first alternating electric signal; means for receiving a beam of acoustic radiation modulated in phase and amplitude by the object in the vicinity of the focus and deriving a second alternating electric signal therefrom; means for providing a reference electric signal derived from the first alternating electric signal and at a known phase; means for mixing coherently the second signal and the reference signal to derive a first in-phase signal; means for mixing the second signal with the reference signal altered in phase by between 80° and 100° to provide a first quadrature signal; means for storing the first in-phase and first quadrature signals; means operative after an interval of time for receiving a beam of acoustic radiation modulated by the same part of the object and deriving a third alternating electric signal therefrom and similarly deriving second in-phase and second quadrature signals; and means for combining the stored first and the second signals so as to sense any change in the object.
Claim 12
Dependent Claim
94 words
Apparatus according to claim 8 further comprising: means for causing relative movement in the focal plane of the object and the focus of the acoustic beam; means for deriving a first in-phase and a first quadrature signal at each of a plurality of relative positions; means for storing each first in-phase and first quadrature signal; means operative after said interval of time for repeating the movement and deriving a second in-phase and a second quadrature signal at each said position; and means for combining for each position the stored first and the second signals.
Claim 13
Independent Claim
108 words
A method for sensing change in an object comprising: irradiating the object with a focused beam of acoustic radiation excited by a first alternating electric signal; receiving a beam of acoustic radiation modulated in phase and amplitude by the object in the vicinity of the focus and for deriving a second alternating electric signal therefrom; providing a reference electric signal derived from the first alternating electric signal and at a known phase; mixing coherently the second signal and the reference signal to derive an in-phase signal; and mixing the second signal and the reference signal altered in phase by between 80° and 100° to derive a quadrature signal.
Claim 14
Independent Claim
108 words
A method for sensing change in an object comprising: irradiating the object with a focused beam of acoustic radiation excited by a first alternating electric signal; receiving a beam of acoustic radiation modulated in phase and amplitude by the object in the vicinity of the focus and for deriving a second alternating electric signal therefrom; providing a reference electric signal derived from the first alternating electric signal and at a known phase; mixing coherently the second signal and the reference signal to derive an in-phase signal; and mixing the second signal and the reference signal altered in phase by between 80° and 100° to derive a quadrature signal.
Claim 15
Dependent Claim
63 words
A method according to claim 10 further comprising: scanning to cause relative movement in the focal plane of the object and the focus of the acoustic beam; storing an in-phase signal and a quadrature signal corresponding to each of a plurality of relative positions of the object; and combining for each position of the object the stored signals with the successively provided signals.
Claim 16
Dependent Claim
41 words
A method according to claim 11 in which the said scanning includes moving the object stepwise in the focal plane in a repeatable pattern and said method includes deriving at each step in the movement an in-phase and a quadrature signal.
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) | 1982-12-24 | 1983-06-25 | 1983-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-24 | 1987-06-25 | 1987-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-24 | 1991-06-25 | 1991-12-25 | $7700.00 | Window Closed / Lapsed |