Retroreflective addressing technique

Claim 1

An optical addressing system for providing location identifications to a controlled vehicle upon alignment of the controlled vehicle with a particular location along a predetermined path of vehicle travel comprising: a plurality of address strips mounted adjacent predetermined locations of the predetermined path with each of said strips comprising a plurality of selectively coated code positions indicative of said predetermined locations along the predetermined path, said code positions being mounted adjacent each other to form a linearly extending array, retroreflective material coating said selectively coated code positions of said address strips, a retroreflectively coated material strip mounted at each end of said array of code positions and offset therefrom to provide a pair of positioning indicators for the controlled vehicle at each of said plurality of address strips; collimated light means carried by the controlled vehicle allowing collimated light to be incident on both said offset positioning indicators and on said address strip when the vehicle is at a predetermined location, first photoelectric means carried by said vehicle for sensing when the controlled vehicle is in an aligned position with one of said address strip locations by sensing when both strips of said pair of positioning indicators are aligned with said first photoelectric means, said first Photoelectric means serving to emit a control signal indicative of the alignment of the controlled vehicle, and second photoelectric means carried by said vehicle for sensing one of said address strips in response to said control signal by sensing said collimated light reflected by said code positions whenever said first photoelectric means senses the aligned position of the controlled vehicle with said pair of positioning indicators, said second photoelectric means serving to emit an electrical signal indicative of said sensed predetermined location in response to sensing of said light.