Super-directional loudspeaker using ultrasonic wave

A super-directional loudspeaker comprising:

• a continuous supporting member having a concave surface;
• electro-acoustic transducer elements fixed to said supporting member;
• said elements being designed to receive an electrical input signal and to produce acoustic vibrations according to said electrical input signal thus received, thereby emitting directional ultrasonic waves in the air;
• said elements being arranged along said concave surface of said supporting member in such a way that said directional ultrasonic waves emitted by said elements propagate in the air to converge on a listening point in front of said concave surface;
• wherein said electro-acoustic transducer elements are arranged circularly around the center of said concave surface of said supporting member.

A super-directional loudspeaker comprising:

• a supporting member having a concave surface;
• electro-acoustic transducer elements fixed to said supporting member;
• said elements being designed to receive an electrical input signal and to produce acoustic vibrations according to said electrical input signal thus received, thereby emitting directional ultrasonic waves in the air;
• said elements being arranged circularly along said concave surface of said supporting member in such a way that said directional ultrasonic waves emitted by said elements propagate in the air to converge on a listening point in front of said concave surface;
• and
• a listener position recognizer and a curvature controller;
• wherein said listener position recognizer recognizes a listener position and outputs a position signal;
• and
• wherein said curvature controller controls a curvature of said concave surface of said supporting member according to said position signal from said listener position recognizer so that said listening point is overlapped with said recognized listener position.

A super-directional loudspeaker comprising:

• a supporting member having a concave surface;
• electro-acoustic transducer elements fixed to said supporting member;
• said elements being designed to receive an electrical input signal and to produce acoustic vibrations according to said electrical input signal thus received, thereby emitting directional ultrasonic waves in the air;
• said elements being arranged circularly along said concave surface of said supporting member in such a way that said directional ultrasonic waves emitted by said elements propagate in the air to converge on a listening point in front of said concave surface;
• wherein said concave surface of said supporting member is formed by sector-shaped blades that are movable around the center of the concave surface.