Patent ID: 11955938
Assignee: THE UNIVERSITY OF TOKYO
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 3:
4. An acoustic output device comprising:
a loudspeaker array with a plurality of loudspeakers arranged in a two-dimensional plane; and
an amplifier array with a plurality of amplifiers, the amplifier array controlling the amplitude and phase of a drive signal for each loudspeaker according to eigenvectors of a predetermined radiation mode of the loudspeaker array,
wherein the distance between a point and each loudspeaker, the upper limit of the frequency range, and the allowable time delay for the drive signals are predetermined so that the deviation in the phase difference from 180° in sound waves generated by two loudspeakers driven at substantially the same amplitude so that the phase difference determined from the eigenvectors is 180° and limited to a predetermined angular range at the point, which is a predetermined distance from the center of the loudspeaker array on the normal of the two-dimensional plane.