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US 4,639,904 AGranted
Sonic transmitters
AssigneeRichard Wolf GmbH
InventorRainer Riedlinger
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AssigneeRichard Wolf GmbH
InventorRainer Riedlinger
Estimating the term…
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 lesser amplitude.
In a sound transmitter for generation of transient acoustic pulses, comprising a spatially curved focussing emitter surface which is represented by the area of at least one emitter, provided that where a plurality of emitters are used they are matched in respect of their period of operation and amplitude, the pulses generated in the focussed volume being engendered by a substantially unipolar and chronologically limited pulse on the emitter surface, an improvement characterised in that the emitter surface deviates from an ideal focussing emitter surface in such a way that as a consequence of the differences in the periods of operation caused by the areal deviation, the chronological rise and fall in the region of the focus of the velocity potential .phi.(t) calculable by means of the Rayleigh integral differ in speed in the region of the focus and that the bipolar pressure pulse p(t) determined by derivation based on time from the substantially unipolar evolution of the velocity potential comprises a brief pulse of high amplitude and an adjacent longer pulse of lower amplitude.
Dependencies are inferred from the claim text.