US3649855A
Expired / Lapsed
US
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Method of and apparatus for optically controlling piezoelectric coupling
Assignee: Leland Stanford Junior University
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Filing: 1970-03-06
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Granted: 1972-03-14
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Expires: 1990-03-06
Abstract
Abstract A method of and apparatus for controlling piezoelectric coupling by directing light in variable fashions against photoconductive material associated with a piezoelectric medium so that a modulation of the conversion of acoustical to electrical energy or vice versa is achieved.
Inventors
- 👤 Bertram A Auld
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:42
CPC Classifications
B; B06; B06B; B06B1/00; B06B1/02; B06B1/06
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
90 words
The method of optically controlling piezoelectric coupling which comprises the steps of associating a photoconductive material with a piezoelectric medium, establishing acoustic energy in said piezoelectric medium, and directing light with variations in space, time, or magnitude against said photoconductive material to modify the electric field distribution in and around the associated piezoelectric medium, thus to vary the coupling between the established acoustic energy and electrical energy in the piezoelectric medium, the directed light being in the form of a beam moved across the photoconductive material in a predetermined fashion.
Claim 2
Independent Claim
90 words
The method of optically controlling piezoelectric coupling which comprises the steps of associating a photoconductive material with a piezoelectric medium, establishing acoustic energy in said piezoelectric medium, and directing light with variations in space, time, or magnitude against said photoconductive material to modify the electric field distribution in and around the associated piezoelectric medium, thus to vary the coupling between the established acoustic energy and electrical energy in the piezoelectric medium, the directed light being in the form of a beam moved across the photoconductive material in a predetermined fashion.
Claim 3
Dependent Claim
42 words
The method of claim 1 which comprises the steps of, applying electrical energy to the piezoelectric medium to generate acoustic energy, and the light is scanned in the form of a narrow beam across the photoconductive medium to establish an acoustic beam.
Claim 4
Dependent Claim
23 words
The method of claim 2 wherein, the light beam is more intense than the surrounding light to produce a negative acoustic beam (hole).
Claim 5
Dependent Claim
22 words
The method of claim 2 wherein, the light beam is less intense than the surrounding light to produce a positive acoustic beam.
Claim 6
Dependent Claim
23 words
The method of claim 2 which comprises the additional step of, scanning the acoustic beam across an object to effect acoustic sensing thereof.
Claim 7
Independent Claim
94 words
The method of optically controlling piezoelectric coupling which comprises the steps of, associating a photoconductive material with a piezoelectric medium, establishing acoustic energy in said piezoelectric medium, directing light with variations in space, time, or magnitude against said photoconductive material to modify the electric field distribution in and around the associated piezoelectric medium, thus to vary the coupling between the established acoustic energy and electrical energy in the piezoelectric medium, and moving the light in the form Of a beam along the photoconductive material to sense the acoustic energy at the position of illumination.
Claim 8
Independent Claim
94 words
The method of optically controlling piezoelectric coupling which comprises the steps of, associating a photoconductive material with a piezoelectric medium, establishing acoustic energy in said piezoelectric medium, directing light with variations in space, time, or magnitude against said photoconductive material to modify the electric field distribution in and around the associated piezoelectric medium, thus to vary the coupling between the established acoustic energy and electrical energy in the piezoelectric medium, and moving the light in the form Of a beam along the photoconductive material to sense the acoustic energy at the position of illumination.
Claim 9
Independent Claim
107 words
The method of optically controlling piezoelectric coupling which comprises the steps of, associating a photoconductive material with a piezoelectric medium, establishing acoustic energy in said piezoelectric medium, and directing light with variations in space, time, or magnitude against said photoconductive material to modify the electric field distribution in and around the associated piezoelectric medium, thus to vary the coupling between the established acoustic energy and electrical energy in the piezoelectric medium, the acoustic energy being established by applying electrical energy to the piezoelectric medium, the light being directed in a pattern having the form of a series of circular rings which effect focusing of the acoustic energy.
Claim 10
Independent Claim
107 words
The method of optically controlling piezoelectric coupling which comprises the steps of, associating a photoconductive material with a piezoelectric medium, establishing acoustic energy in said piezoelectric medium, and directing light with variations in space, time, or magnitude against said photoconductive material to modify the electric field distribution in and around the associated piezoelectric medium, thus to vary the coupling between the established acoustic energy and electrical energy in the piezoelectric medium, the acoustic energy being established by applying electrical energy to the piezoelectric medium, the light being directed in a pattern having the form of a series of circular rings which effect focusing of the acoustic energy.
Claim 11
Dependent Claim
24 words
The method of claim 7 which comprises the additional step of, varying the circular ring pattern of light to vary the acoustic focal point.
Claim 12
Independent Claim
116 words
The method of optically controlling piezoelectric coupling which comprises the steps of, associating a photoconductive material with a piezoelectric medium, establishing acoustic energy in said piezoelectric medium, and directing light with variations in space, time, or magnitude against said photoconductive material to modify the electric field distribution in and around the associated piezoelectric medium, thus to vary the coupling between the established acoustic energy and electrical energy in the piezoelectric medium, generating electric energy in the piezoelectric material by placing an acoustic propagating structure thereagainst and directing the light in a linear separated pattern of one-half a predetermined acoustic wavelength against the photoconductive medium thus to create a constructive interference pattern at a predetermined acoustic frequency.
Claim 13
Independent Claim
116 words
The method of optically controlling piezoelectric coupling which comprises the steps of, associating a photoconductive material with a piezoelectric medium, establishing acoustic energy in said piezoelectric medium, and directing light with variations in space, time, or magnitude against said photoconductive material to modify the electric field distribution in and around the associated piezoelectric medium, thus to vary the coupling between the established acoustic energy and electrical energy in the piezoelectric medium, generating electric energy in the piezoelectric material by placing an acoustic propagating structure thereagainst and directing the light in a linear separated pattern of one-half a predetermined acoustic wavelength against the photoconductive medium thus to create a constructive interference pattern at a predetermined acoustic frequency.
Claim 14
Dependent Claim
55 words
Optical control apparatus for piezoelectric coupling which comprises, a photoconductive, piezoelectric transducer, means for applying electric fields to said transducer to generate acoustic energy, means for directing a beam of light against said transducer to vary the piezoelectric coupling and control the acoustic output, and means for scanning the beam of light across the transducer.
Claim 15
Dependent Claim
55 words
Optical control apparatus for piezoelectric coupling which comprises, a photoconductive, piezoelectric transducer, means for applying electric fields to said transducer to generate acoustic energy, means for directing a beam of light against said transducer to vary the piezoelectric coupling and control the acoustic output, and means for scanning the beam of light across the transducer.
Claim 16
Dependent Claim
66 words
Optical control apparatus for piezoelectric coupling which comprises, a photoconductive, piezoelectric transducer, means for applying electric fields to said transducer to generate acoustic energy, means for directing light against said transducer to vary the piezoelectric coupling and control the acoustic output, and a mask having a light-transmitting pattern in the form of a sequence of circular rings disposed between said light directing means and said transducer.
Claim 17
Dependent Claim
66 words
Optical control apparatus for piezoelectric coupling which comprises, a photoconductive, piezoelectric transducer, means for applying electric fields to said transducer to generate acoustic energy, means for directing light against said transducer to vary the piezoelectric coupling and control the acoustic output, and a mask having a light-transmitting pattern in the form of a sequence of circular rings disposed between said light directing means and said transducer.
Claim 18
Dependent Claim
32 words
Optical control apparatus according to claim 11 which comprises, an optical imaging system between said mask and said transducer to vary the dimensions of the circular ring light pattern on said transducer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-14 | 1975-09-13 | 1976-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-14 | 1979-09-13 | 1980-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-14 | 1983-09-13 | 1984-03-14 | $7700.00 | Window Closed / Lapsed |