The invention relates to a method for evaluating multiple received signals (6, 8, 11), wherein the method has the following steps: sending a transmission signal (3) receiving a first signal (6), which contains the transmission signal via a first receiver (5) and receiving a second signal (8), which contains the transmission signal via a second receiver (7), characterized in that to evaluate the received signals (6, 8), the received signals (6, 8) are compared with one another, wherein the comparison comprises determination of a time difference and/or phase difference between the first signal (6) and the second signal (8).

The invention relates to a method for evaluating multiple received signals (6, 8, 11), wherein the method has the following steps: sending a transmission signal (3) receiving a first signal (6), which contains the transmission signal via a first receiver (5) and receiving a second signal (8), which contains the transmission signal via a second receiver (7), characterized in that to evaluate the received signals (6, 8), the received signals (6, 8) are compared with one another, wherein the comparison comprises determination of a time difference and/or phase difference between the first signal (6) and the second signal (8).

A method for detecting movements of a plurality of points (P) of a surface (21), comprising a measuring step during which an incident ultrasonic wave is emitted into the air towards the surface and an ultrasonic wave reflected into the air by the surface (21) is detected. During the measuring step, each measuring point is illuminated by the incident ultrasonic wave at a multiplicity of angles of incidence, and the reflected ultrasonic wave is detected by a network of receiving transducers (3) comprising a plurality of ultrasonic receiving transducers (3a). The movements of the surface are determined at a measuring point by determining a delay and/or a phase shift between two beam-forming signals for said measuring point.

A method for detecting movements of a plurality of points (P) of a surface (21), comprising a measuring step during which an incident ultrasonic wave is emitted into the air towards the surface and an ultrasonic wave reflected into the air by the surface (21) is detected. During the measuring step, each measuring point is illuminated by the incident ultrasonic wave at a multiplicity of angles of incidence, and the reflected ultrasonic wave is detected by a network of receiving transducers (3) comprising a plurality of ultrasonic receiving transducers (3a). The movements of the surface are determined at a measuring point by determining a delay and/or a phase shift between two beam-forming signals for said measuring point.

A plurality of control points (10) are defined which each have a known spatial relationship relative to an array of transducers. An amplitude is assigned to each control point (12). A matrix (16) is produced containing elements which represent, for each of the control points, the effect that producing a modeled acoustic field having the assigned amplitude with a particular phase at the control point has on the consequential amplitude and phase of the modeled acoustic field, at the other control points (14). Eigenvectors of the matrix (18) are determined, each eigenvector representing a set of phases and relative amplitudes of the modeled acoustic field at the control points. One of the sets (20) is selected and the transducer array is operated to cause one or more of the transducers to output an acoustic wave each having an initial amplitude and phase such that the phases and amplitudes of the resultant acoustic field at the control points correspond to the phases and relative amplitudes of the selected set (22, 24).

A plurality of control points (10) are defined which each have a known spatial relationship relative to an array of transducers. An amplitude is assigned to each control point (12). A matrix (16) is produced containing elements which represent, for each of the control points, the effect that producing a modeled acoustic field having the assigned amplitude with a particular phase at the control point has on the consequential amplitude and phase of the modeled acoustic field, at the other control points (14). Eigenvectors of the matrix (18) are determined, each eigenvector representing a set of phases and relative amplitudes of the modeled acoustic field at the control points. One of the sets (20) is selected and the transducer array is operated to cause one or more of the transducers to output an acoustic wave each having an initial amplitude and phase such that the phases and amplitudes of the resultant acoustic field at the control points correspond to the phases and relative amplitudes of the selected set (22, 24).

One example includes an ultrasonic ranging system. The system includes an ultrasonic transducer configured to transmit an ultrasonic signal and to receive reflected ultrasonic signal paths having been reflected from a plurality of target objects during a ranging operation. The system also includes a ranging processor configured to detect a location associated with the plurality of target objects based on monitoring phase information associated with the reflected ultrasonic signal paths.

One example includes an ultrasonic ranging system. The system includes an ultrasonic transducer configured to transmit an ultrasonic signal and to receive reflected ultrasonic signal paths having been reflected from a plurality of target objects during a ranging operation. The system also includes a ranging processor configured to detect a location associated with the plurality of target objects based on monitoring phase information associated with the reflected ultrasonic signal paths.

The present invention concerns a method and apparatus for the modulation of an acoustic field for providing tactile sensations. A method of creating haptic feedback using ultrasound is provided. The method comprises the steps of generating a plurality of ultrasound waves with a common focal point using a phased array of ultrasound transducers, the common focal point being a haptic feedback point, and modulating the generation of the ultrasound waves using a waveform selected to produce little or no audible sound at the haptic feedback point.

The present invention concerns a method and apparatus for the modulation of an acoustic field for providing tactile sensations. A method of creating haptic feedback using ultrasound is provided. The method comprises the steps of generating a plurality of ultrasound waves with a common focal point using a phased array of ultrasound transducers, the common focal point being a haptic feedback point, and modulating the generation of the ultrasound waves using a waveform selected to produce little or no audible sound at the haptic feedback point.