KEY-LESS ENTRY CONTROL SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a key-less entry control system at a low cost and in a precisely tuning structure. SOLUTION: The receiving portion 1a of a receiver 1 constructed of a super heterodyne type includes a sweeping means 2b for sweeping the oscillation frequency of a local oscillator 104 and a sweep control means 2a for controlling it. The sweep control means 2a searches a received wave signal in accordance with the intensity of a received signal detected by a received signal intensity detecting means 111 and stops sweeping at a tuning point. An unmodulated wave is sent from a transmitter 4a to search and tune the received wave signal for better S/N receiving and more precise tuning. The transmitter 4a with a vibrator 4031, if not so stable and inexpensive, can be surely tuned.