Patent ID: 6617959
Filing Date: 2003-09-09
Classification: G07C

Abstract:
A non-contact chip lock and a battery-free key thereof, said key comprising an insertion portion in which an internal circuit composed of a microprocessor, a residual magnetism eraser, an inductive choke, a current-rectifying and voltage-stabilizing unit, and an electric pulse counting unit is provided; said lock comprising a cylindrical body in which an internal circuit composed of a microcontroller, a comparator, a transmitting coil unit, a position switch, and an unlocking unit is provided; whereby when said insertion portion of said key is inserted into said cylindrical body of said lock, said inductive choke in said key is induced by a magnetic field generated by said transmitting coil unit in said lock and together with said transmitting coil unit to form a flyback transformer; and said key to operate normally without any battery and to modulate and demodulate special signals for encrypted data to be bi-directionally transmitted between said key and said lock, wherein said encrypted data is transmitted from said lock to said key through the flyback transformer so that said key reads said encrypted data and transmits a data to said lock through the flyback transformer, and wherein said comparator and said microcontroller of said lock reads and compares said data and if said data transmitted by said key is compatible with said encrypted data of said lock, said microcontroller of said lock outputs an unlocking signal to unlock said lock, while said key is non-directionally inserted into said lock without the need of turning said key to any specific position in said lock.