Patent ID: 7224955
Filing Date: 2007-05-29
Classification: H04M

Abstract:
1. An apparatus for sending an emergency rescue signal using a mobile communication terminal, comprising: a keypad having a rescue requesting button; a modem unit for requesting emergency rescue by engaging the rescue requesting button and controlling transmission of an emergency rescue signal according to a remote control signal received from an emergency rescuer; an emergency rescue signal sending unit for sending the emergency rescue signal and for detecting an exact position of a rescue requester according to controlling of a modem unit; wherein the emergency rescue signal sending unit comprises an ultrasonic wave module for generating an ultrasonic signal for detecting the exact position of the rescue requested, according to controlling of the modem unit, and a power supply unit for supplying power to the ultrasonic wave module according to controlling of the modem unit; wherein the ultrasonic wave module comprises: an oscillator for oscillating a signal of a predetermined frequency; a counter for dividing the frequency signal from the oscillator into a predetermined number of different division ratios; a multiplexer for multiplexing a predetermined number of counting signals outputted from the counter; a pre-amplifying unit for amplifying the multiplexed predetermined number of counting signals using a predetermined number of corresponding pre-amplifiers each having a different amplifying gain; an analog switch for selectively outputting a signal among signals outputted from the pre-amplifying unit; a power amplifier for amplifying the signal outputted from the analog switch, and outputting the power-amplified signal to a speaker; and a micro-computer for controlling multiplexing of the pre-determined number of counting signals and controlling the analog switch, according to controlling of the modem unit.