A NEW OPTICAL PATTERN RECOGNITION SYSTEM WHICH PERFORMS COMPARISONS OF IMAGE SEGMENTS IN FREE SPACE IS DESCRIBED. THE SCIENTIFIC AND PRACTICAL HISTORY OF THE OPTICAL CORRELATOR TECHNOLOGY IS REVIEWED. SEVERAL APPLICATIONS ARE DISCUSSED AND EXPLAINED. THESE INCLUDE HIGH-SPEED ALPHANUMERIC INSPECTION AND IDENTIFICATION, FOOD PACKAGE EVALUATION, AND PART INSPECTION. THE MASSIVELY PARALLEL PROCESSING NATURE, AND INPUT POSITIONAL INVARIANCE ARE EXPLAINED. ONE RESULT OF THE PROCESSING NATURE IS THE CAPABILITY OF THE SYSTEM TO PERFORM MORE THAN 250 FULL IMAGE COMPARISONS PER SECOND (15,000 COMPARISONS PER MINUTE).