DISTANCE SENSOR FOR DOOR LOCK SYSTEM

摘要

PURPOSE: A distance sensor for door lock system is provided to release automatically a locking state of a door by performing a communication operation between a wireless communication card and a main unit installed within a vehicle. CONSTITUTION: A distance sensor for door lock system includes an antenna(150), a demodulation circuit, a comparator(8), and a reference voltage generation circuit(16). The antenna(150) is used for receiving electric waves from an user's electric wave generator. The demodulation circuit is used for demodulating the received signal. The comparator(8) is used for comparing a demodulated signal of the demodulation circuit with the reference voltage. The comparator(8) outputs the first and the second outputs according to the compared results. The reference voltage generation circuit(16) is used for generating the reference voltage.