Sonic transmitters
US4639904A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 29, 1986 |
| Grant date | Jan 27, 1987 |
| Priority date | — |
| Expiry date | Jan 29, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/387
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sound transmitter for generation of transient acoustic pulses, comprising a spatially curved focussing emitter surface which is represented by the area of a single active or passive emitter or by the areas of several emitters matched in respect of their period of operation and amplitude. The pulses occurring in the region of the focus are generated by a substantially unipolar and chronologically limited pressure and/or velocity evolution at the emitter surface. So that a substantially unipolar pressure pulse may equally be generated at the focus of an emitter surface of this nature, the emitter surface deviates in a specified manner from an ideally focussing emitter surface so that as a result of the differences in period of operation caused by a real deviation in the region of the focus, the chronological increase and decrease of the velocity potential in the focal region calculable by means of the Rayleigh integral differ in speed, so that the pressure evolution determined from the substantially unipolar evolution of the velocity potential by derivation based on time has a brief pulse of high amplitude at the beginning or end, which is followed or preceded by a longer pulse of …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.