Acoustic holography apparatus
US4070643A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 22, 1976 |
| Grant date | Jan 24, 1978 |
| Priority date | — |
| Expiry date | Jun 22, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S15/897
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus and method for forming acoustic hologram patterns, comprising a receiver transducer for detecting acoustic waves scattered by an object, a scanning system for moving the receiver relative to the object, a sampling system for taking samples of a signal derived from the receiver transducer at selected instants relative to the phase of the acoustic signals at the transmitter, the selected instants being determined according to the phase of a chosen notional reference wave at the position of the receiver transducer relative to the phase of the chosen notional reference wave at a datum point, and a system for plotting the samples versus the displacement of the receiver transducer so as to form a graphical diagram representing an acoustic hologram of the object. The receiver signals are preferably applied to a phase-locked frequency-multiplier circuit and the samples taken from the output of this circuit. The sampling system may include a switch circuit arranged to apply a series of predetermined voltages in sequence to a comparator controlling a sampling gate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.