Patent ID: 7545255

Claim:
An electronic key system for use in a vehicle comprising: a terminal installed in the vehicle to process predetermined information; a plurality of electronic keys, each storing an identification code and transmitting the identification code to the vehicle, wherein the electronic keys include a master key and a sub-key, and wherein the identification codes include a master identification code stored in the master key and a sub-identification code stored in the sub-key; a comparing means arranged in the vehicle and storing a plurality of verification codes associated with the identification codes, wherein the comparing means retrieves the identification code of one of the electronic keys and compares the retrieved identification code with an associated one of the verification codes; and a control means for generating access right information that restricts activation of the terminal when the retrieved identification code is the sub-identification code and providing the terminal with the access right information, wherein the control means enables starting of an engine of the vehicle or unlocking doors of the vehicle when the retrieved identification code matches with the associated one of the verification codes; wherein the terminal is one of a plurality of terminals, and the control means generates the access right information that corresponds to the sub-identification code and selectively restricts the usage of each terminal in accordance with the sub-identification code when the sub-identification code matches with the associated one of the verification codes and starting of an engine or unlocking doors of the vehicle is enabled, and wherein the control means generates the access right information that corresponds to the master identification code and permits the usage of all of the plurality of terminals when the master identification code matches with the associated one of the verification codes and starting of an engine of the vehicle or unlocking doors of the vehicle is enabled, and wherein when each of the plurality of terminals receives the access right information generated from the sub-identification code from the control means, each terminal interprets the access right information generated from the sub-identification code to determine operation of a terminal that is to be restricted and that differs from that of other terminals in accordance with the access right information.