US3791736A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus utilizing the phase velocity difference of light rays for measuring the velocity of a moving object
Assignee: United States Department of the Air Force
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Filing: 1972-04-28
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Granted: 1974-02-12
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Expires: 1992-04-28
Abstract
Abstract Light transmitted through an optical birefringent retardation plate emerges as ordinary (O) and extraordinary (E) rays having a phase velocity difference characteristic of the plate material and thickness. Retardation plate motion introduces an additional phase velocity difference between the E- and O-rays that is a measure of the velocity of such motion. Velocity of a moving object is measured by affixing an optical retardation plate to the moving object, detecting the E- and O-ray phase velocity difference of coherent light transmitted through the moving plate, and converting the phase velocity difference values so obtained to linear and angular velocity values.
Inventors
- 👤 R Newburg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:22
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/36; G01P3/366
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
118 words
The method of measuring the velocity of a moving object comprising the steps of obtaining the phase velocity difference between the E- and Orays of light transmitted through a given stationary optical birefringent retardation plate by a given stationary coherent light source, affixing said retardation plate to said moving object, projecting light through the moving retardation plate with said stationary coherent light source, obtaining the phase velocity difference between the E- and Orays of the light transmitted through the moving retardation plate, subtracting the E- and O-ray phase velocity difference obtained from the starionary retardation plate from the E and O-ray phase velocity difference obtained from the moving retardation plate, and converting the resultant value into velocity measure.
Claim 2
Independent Claim
118 words
The method of measuring the velocity of a moving object comprising the steps of obtaining the phase velocity difference between the E- and Orays of light transmitted through a given stationary optical birefringent retardation plate by a given stationary coherent light source, affixing said retardation plate to said moving object, projecting light through the moving retardation plate with said stationary coherent light source, obtaining the phase velocity difference between the E- and Orays of the light transmitted through the moving retardation plate, subtracting the E- and O-ray phase velocity difference obtained from the starionary retardation plate from the E and O-ray phase velocity difference obtained from the moving retardation plate, and converting the resultant value into velocity measure.
Claim 3
Dependent Claim
146 words
Apparatus for measuring the velocity of a moving object comprising an optical birefringent retardation plate affixed to the moving object, a stationary remotely located coherent light source positioned to transmit light through said retardation plate, means for detecting the phase velocity difference values between the E- and O-rays of the light transmitted through the moving retardation plate, and a logic circuit connected to receive the output of said means for detecting phase velocity difference values, said logic circuit having the phase velocity difference value between the E- and O-rays of coherent light transmitted through said retardation plate in a stationary condition written into its memory circuits, Said logic circuit being adapted to convert the phase velocity difference value stored in its memory circuits and the phase velocity difference values received from said means for detecting the phase velocity difference values into linear and angular velocity values.
Claim 4
Dependent Claim
146 words
Apparatus for measuring the velocity of a moving object comprising an optical birefringent retardation plate affixed to the moving object, a stationary remotely located coherent light source positioned to transmit light through said retardation plate, means for detecting the phase velocity difference values between the E- and O-rays of the light transmitted through the moving retardation plate, and a logic circuit connected to receive the output of said means for detecting phase velocity difference values, said logic circuit having the phase velocity difference value between the E- and O-rays of coherent light transmitted through said retardation plate in a stationary condition written into its memory circuits, Said logic circuit being adapted to convert the phase velocity difference value stored in its memory circuits and the phase velocity difference values received from said means for detecting the phase velocity difference values into linear and angular velocity values.
Claim 5
Dependent Claim
25 words
Apparatus for measuring the velocity of a moving object as defined in claim 2 wherein said optical birefringent retardation plate comprises a calcite crystal plate.
Claim 6
Dependent Claim
29 words
Apparatus for measuring the velocity of a moving object as defined in claim 3 wherein said means for detecting phase velocity difference between E- and O-rays comprises a polarimeter.
References Cited (Backward Citations)
US3506362A
Cited
US3692385A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |