Patent ID: 7176783
Filing Date: 2007-02-13
Classification: B60R,G07C

Abstract:
1. A device for identifying authentic information and enabling an action, comprising: a) a base unit and a key unit transmitting information to the base unit, the base unit detecting the information and comparing it with predetermined information, the base unit enabling the action when the detected information matches the predetermined information; b) the base unit and the key unit include respective accurately-timed digital generators running essentially synchronously with respect to one another and generating digital output information that changes at predetermined time intervals; c) the key unit combining the digital information of the key unit digital generator with a stored identification code in accordance with a predetermined coding rule to form a coded information item, the key unit including: d) the base unit using the predetermined coding rule to code the predetermined information with the digital information of the base unit digital generator to form a predetermined coded information item, and comparing the predetermined coded information item with the coded information item communicated by the key unit, the base unit enabling the action when the coded information item communicated matches the predetermined coded information item; e) the base unit transmitting a radio-frequency carrier signal; f) the key unit including a controllable electronic switch switching an antenna between an essentially matched state and a mismatched state in accordance with the coded information item, and the antenna reflecting the received radio-frequency carrier signal in accordance with the time changing digital coded information; and g) the base unit receiving and evaluating the reflected signal.