Ultrasonic speaker system
AssigneePanasonic Corporation
InventorsKazuhisa KOTEGAWA, Fumiyasu KONNO, Katsu TAKEDA
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Abstract
An ultrasonic speaker system has a first variable gain block, a modulation block, a second variable gain block, an ultrasonic actuator, and a controller, wherein the controller controls gain of the first variable gain block so that a modulation degree of a modulated signal becomes a predetermined value, and when the controller raises the gain of the first variable gain block, the controller lowers the gain of the second variable gain block, while when the controller lowers the gain of the first variable gain block, the controller raises the gain of the second variable gain block.
Claims6
An ultrasonic speaker system comprising:
- a first variable gain block for receiving a speech signal outputted from a speech signal source;
- a modulation block for receiving the speech signal outputted from the first variable gain block;
- a second variable gain block for receiving a modulated signal generated in the modulation block based on the speech signal;
- an ultrasonic actuator that is driven by the modulated signal outputted from the second variable gain block, coverts the modulated signal to an acoustic wave of a finite amplitude level, and radiates the acoustic wave into a medium;
- and
- a controller that controls the first variable gain block and the second variable gain block,
- wherein the controller controls gain of the first variable gain block so that a modulation degree of the modulated signal becomes a predetermined value,
- when the controller raises the gain of the first variable gain block, the controller lowers gain of the second variable gain block, and
- when the controller lowers the gain of the first variable gain block, the controller raises the gain of the second variable gain block.
Dependencies are inferred from the claim text.