HANDS-FREE UNIT HAVING A SYSTEM FOR LIMITING A USAGE OF A PORTABLE TELEPHONE, SPECIALLY IN REFERENCE TO PROHIBITING A USER FROM USING THE PORTABLE TELEPHONE WITHOUT THE HANDS-FREE UNIT WHILE A USER IS DRIVING

摘要

PURPOSE: A hands-free unit having a system for limiting a usage of a portable telephone is provided to restore a pressurized spring into an original state to turn on a frequency cut-off unit when a user separates a portable telephone from a hands-free unit, so that the frequency cut-off unit can generate an interference propagation, thereby prohibiting the user from using the telephone without the hands-free unit. CONSTITUTION: A hands-free body(22) is mounted on a predetermined position in a car, and comprises a mounting portion(22a) where a portable telephone(30) is detachable therefrom. A frequency cut-off unit(23) is disposed on the hands-free body(22), and cuts off a receiving frequency transmitted to the portable telephone(30) and a transmission frequency received from the portable telephone(30). A switch(24) is mounted on one side of the hands-free body(22), and turns on/off the frequency cut-off unit(23).