REPRODUCTION PREVENTION KEY AND PRODUCTION METHOD THEREOF

摘要

PURPOSE: The key and the production method thereof which is impossible to reproduce using a fine pattern of a bar code shape and spreading lusterless opaque resin. CONSTITUTION: The installation of a key composed of an insulation has the steps of:forming a groove(440) for guiding so a key(410) as to be accurately inserted into a lock and withdrawn from the lock at the center part of the key(410); spreading a conductive metal by electric gilding on the 1st surface(412) and the 2nd face(414) placed in the opposite direction of the 1st face(412) to form a metal thin film(420,430); generating a magnetic field by an eddy current induction at a conduction unit(424) if the magnetic field is fed to the key(410); not generating the magnetic field because the eddy current is not induced at the insulation unit(422); setting a code by a reaction difference of the magnetic field of the conduction unit(424) and the insulation unit(422).