Patent ID: 6195421
Filing Date: 2001-02-27
Classification: H04M

Abstract:
A caller ID device with a power saving function, electrically coupled to a pair of telephone lines together with a telephone, comprising:a CAS receiver for receiving a CAS signal from the pair of the telephone lines and then transmitting a CAS detecting signal in response to the received CAS signal after the CAS receiver is activated at an off-hook state;a current limiting circuitry having an input end electrically coupled to the telephone and an output end electrically coupled to the CAS receiver for directing an operating current from the pair of telephone lines to the CAS receiver through the telephone at the off-hook state;an FSK receiver for receiving and demodulating an FSK modulated signal from the pair of the telephone lines into an FSK demodulated signal after the FSK receiver is activated;a controller for activating the CAS receiver when the controller detects the telephone is at the off-hook state, for activating the FSK receiver when receiving the CAS detecting signal from the CAS receiver, for receiving the FSK demodulated signal from the FSK receiver and for inactivating the activated FSK receiver once the controller detects no FSK demodulated signal received or already receives the FSK demodulated signal;a display for displaying the FSK demodulated signal output from the controller; anda battery having a positive polarity electrically coupled to the FSK receiver and the controller for power supply and a negative polarity electrically coupled to ground.