| 摘要 |
PROBLEM TO BE SOLVED: To simplify the structure of a theft-prevention key device and to enhance the reliability of the device. SOLUTION: An annular coil 6 which is operated and excited with a key set in a predetermined position is provided on the key hole side of a key cylinder 2, and an induction coil 8 produceable an induced electromotive force through the excitation, a capacitor charged by the electromotive force, and an infrared LED 9 transmitting an ID code prestored in a storage circuit are provided at a key handle part 1a. A photosensor 10a for receiving an infrared signal is provided in the key cylinder 2, and the signal received is checked with an ID signal prestored in a control unit 11 to determine whether or not the signal received is the correct one. An engine start permission signal is output to an external engine control circuit only when the signal is the correct one. Thus, dispensing with supplying electricity through the connection of a battery or a power terminal, the constitution of key device can be simplified, and reliability can be enhanced by eliminating contact parts. |
