Vehicle ignition lock employing light conductor - has fibre optic conductor from key emitter to detector

摘要

The lock for car steering and ignition application, has a cavity into which a key is inserted. The key (52) incorporates a fibre-optic conductor (54) joining two positions on the key surface, the positions being displaced longitudinally on the key body and having an angular displacement on the circumference of the key cross-section. A light emitter (60) and a light detector (55) are located in the walls (51) of the cavity in positions corresponding to the ends of the light conductor. The longitudinal and angular position of the emitter, detector and conductor ends may be varied to attain a wide range of codes. Any electromagnetic signal may be used and frequency filters employed to increase security.