Plural track shaft angle encoding system using exclusive or logic

Claim 1

AN ENCODING SYSTEM COMPRISING CODE MEANS IN THE FORM OF AN ARRAY INCLUDING FIRST TRACK MEANS AND SECOND TRACK MEANS, SENSING MEANS IN THE FORM OF AN ARRAY INCLUDING FIRST PHOTOCELL MEANS AND SECOND PHOTOCELL MEANS, SAID CODE MEANS AND SAID SENSING MEANS BEING CONSTRAINED FOR RELATIVE MOVEMENT WITH SAID FIRST TRACK MEANS AND SAID FIRST PHOTOCELL MEANS IN REGISTRATION AND SAID SECOND TRACK MEANS AND SAID SECOND PHOTOCELL MEANS IN REGISTRATION, ILLUMINATION MEANS FOR DIRECTING RADIATION TO SAID TRACK MEANS, EACH OF SAID TRACK MEANS HAVING FIRST REGIONS AND SECOND REGIONS FOR DIFFERENTLY ASSOCIATING SAID RADIATION WITH SAID PHOTOCELL MEANS REGISTERED THEREWITH, SAID FIRST PHOTOCELL MEANS GENERATING A FIRST PLURALITY OF PREDETERMINEDLY DIFFERENT SIGNALS REPRESENTING RELATIVE POSITIONS OF SAID CODE MEANS AND SAID SENSING MEANS, SAID SECOND PHOTOCELL MEANS GENERATING A SECOND PLURALITY OF PREDETERMINEDLY DIFFERENT SIGNALS REPRESENTING RELATIVE POSITIONS OF SAID CODE MEANS AND SAID SENSING MEANS, FIRST LOGIC MEANS FOR REPRESENTING SAID FIRST PLURALITY OF PREDETERMINEDLY DIFFERENT SIGNALS AS A FIRST PLURALITY OF DIGITS, SECOND LOGIC MEANS FOR REPRESENTING SAID SECOND PLURALITY OF PREDETERMINEDLY DIFFERENT SIGNALS AS A SECOND PLURALITY OF DIGITS, AND CARRY-OVER MEANS FOR CONTROLLING SAID SECOND PLURALITY OF SIGNALS IN RESPONSE TO SAID FIRST PLURALITY OF SIGNALS, SAID LOGIC MEANS PERFORMING EXCLUSIVE-OR OPERATIONS.