Patent US 4,288,780

A pattern recognition system for protecting against the theft of automobiles, the unauthorized opening of doors, the unauthorized opening of other items such as brief cases and the like is disclosed. The system of this invention includes a matrix card having a matrix array, a card reader and a comparator. Elements of the array on the card are perforated to provide a coded pattern on the card. The reader senses these perforations and senses those elements of the array that are not perforated. The output of the reader is applied to the comparator which is pre-set according to the code on the matrix card. If the pre-set code in the comparator matches the code on the card, the comparator provides a positive recognition output signal.