Patent US3706965A successfully refreshed from Google Patents.
US3706965A
Expired / Lapsed
US
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Real-time acoustic imaging system
Assignee: Zenith Electronics LLC
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Filing: 1971-08-04
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Granted: 1972-12-19
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Expires: 1991-08-04
Abstract
Abstract To produce an acoustic image or hologram of an object irradiated by acoustic waves, a system includes a sheet of elasto-optically anisotropic material that responds to the acoustic waves by exhibiting unequal strain-optic coefficients in orthogonal directions related to the path of the acoustic waves. A linearly polarized monochromatic beam of light is projected toward a point in the sheet, while a detector responds to light reflected from the sheet and develops a signal that represents variations caused by the sheet. Disposed in the light path is a quarter-waveplate that converts the original linear polarization into circular polarization. A polarization analyzer, disposed in the light path beyond the sheet and between the quarter-waveplate and the detector, is oriented to select a polarization component of the light that exhibits an amplitude modulation component at the frequency of the acoustic waves.
Inventors
- 👤 Adrianus Korpel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:31
CPC Classifications
G; G03; G03H; G03H3/00; G02; G02F; G02F1/00; G02F1/01; G02F1/11
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
164 words
A system productive of information representative of an object irradiated by acoustic waves, comprising: a sheet of elasto-optically anisotropic material responsive to acoustic waves received along a predetermined path for exhibiting unequal strain-optic coefficients in orthogonal Directions related to the direction of said path; means for launching said acoustic waves toward said sheet along said path; a medium in which said object is immersed in said path and propagative of said acoustic waves; Means for directing linearly polarized monochromatic light toward a point in said sheet; detector means, responsive to a portion of said light reflected from said sheet, for developing a signal representative of variations in said light effected by action of said sheet; a quarter-waveplate disposed in the light path for converting said linear polarization to circular polarization; and a polarization analyzer disposed in the light path beyond said sheet between said quarter-waveplate and said detector means and oriented to select a polarization component modulated at the frequency of said acoustic waves.
Claim 2
Independent Claim
164 words
A system productive of information representative of an object irradiated by acoustic waves, comprising: a sheet of elasto-optically anisotropic material responsive to acoustic waves received along a predetermined path for exhibiting unequal strain-optic coefficients in orthogonal Directions related to the direction of said path; means for launching said acoustic waves toward said sheet along said path; a medium in which said object is immersed in said path and propagative of said acoustic waves; Means for directing linearly polarized monochromatic light toward a point in said sheet; detector means, responsive to a portion of said light reflected from said sheet, for developing a signal representative of variations in said light effected by action of said sheet; a quarter-waveplate disposed in the light path for converting said linear polarization to circular polarization; and a polarization analyzer disposed in the light path beyond said sheet between said quarter-waveplate and said detector means and oriented to select a polarization component modulated at the frequency of said acoustic waves.
Claim 3
Dependent Claim
86 words
A system as defined in claim 1 wherein, with reference to an X axis defined as normal to said sheet, said directing means projects and light along a course at an acute angle with respect to said X axis, said launching means orients the path of said acoustic waves at least generally in the direction of the X axis, and said analyzer is oriented to pass selectively components of said light instaneously polarized in a direction forming an acute angle with respect to said X axis.
Claim 4
Dependent Claim
50 words
A system as defined in claim 1 in which said sheet is transparent to said light, in which a film reflective of said light is disposed on the surface of said sheet facing said medium, and in which said directing means projects said light through said sheet to said film.
Claim 5
Dependent Claim
39 words
A system as defined in claim 1 in which said sheet is optically isotropic and in which said directing means projects and said light toward said sheet at an acute angle with respect to a normal to said sheet.
Claim 6
Dependent Claim
31 words
A system as defined in claim 1 in which said sheet effectively is optically non-isotropic and in which said directing means projects said light in a direction perpendicular to said sheet.
Claim 7
Dependent Claim
15 words
A system as defined in claim 2 in which said acute angles are substantially 45*.
Claim 8
Dependent Claim
26 words
A system as defined in claim 1 in which said sheet has a thickness not greater than one-half wavelength of the acoustic waves in said sheet.
Claim 9
Dependent Claim
122 words
A system as defined in claim 5 wherein, with reference to tri-coordinate axes having an X axis normal to said sheet and Y and Z axes lying in said sheet and being chosen with respect to the crystallographic axes of said material, said directing means projects said light substantially along said X axis and orients the polarization of said light at an acute angle with respect to the Y or Z axes, said launching means orients the path of said acoustic waves at least generally in a direction opposite that of said light, and said analyzer is oriented to pass selectively components of said light instantaneously polarized in a direction forming an acute angle with respect to the Y or Z axes.
References Cited (Backward Citations)
US3585848A
Cited
US3633407A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-19 | 1976-06-19 | 1976-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-19 | 1980-06-19 | 1980-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-19 | 1984-06-19 | 1984-12-19 | $7700.00 | Window Closed / Lapsed |