公开(公告)号：US20200228897A1

公开(公告)日：2020-07-16

申请号：US16254680

申请日：2019-01-23

Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE

Inventor： Chi Hoon CHOI ,  Ji Eun CHOI ,  Young Jun LEE ,  Heesun PARK ,  Young Hyoun KWON ,  Sae-Hoon JU ,  Kyung-Hoon LEE

IPC: H04R3/00

Abstract: An apparatus and method for preventing an electronic device from recording. The apparatus includes a control unit for generating a first modulation signal and controlling the components of the apparatus; a first modulation unit for modulating the first modulation signal to an FM signal; an ultrasonic signal generation unit for generating an ultrasonic signal, the frequency of which is adjusted by changing the value of at least one of a variable resistor and a variable capacitor depending on the magnitude of the FM signal; an amplification unit for increasing or decreasing the magnitude of the ultrasonic signal; a resonance unit for increasing the voltage to be applied to a transducer by generating resonance; and an ultrasound output unit for converting electrical signals into ultrasonic signals using the transducer and radiating a recording prevention signal, converted into the ultrasonic signal, to the microphone of an electronic device.