Angular displacement encoder with photoelectric pickoffs at different radial and angular positions

Claim 1

A ROTARY DIGITAL ENCODER COMPRISING A CYLINDRICAL HOUSING, A PLURALITY OF PHOTO-ELECTRIC DEVICES SUPPORTED IN SAID HOUSING IN INDIVIDUAL RADIAL ARRAY WITH RESPECT TO THE ENCODER AXIS, A MASK SECURED IN THE HOUSING CONTAINING A LIGHT TRANSMITTING APERTURE OPPOSITE EACH OF SAID DEVICES, A LAMP MOUNTED ADJACENT EACH OF SAID APERTURES FOR DIRECTING A BEAM OF LIGHT TOWARDS EACH OF SAID DEVICES, AND A CODE DISC ROTATABLE BETWEEN SAID DEVICES AND THEIR RESPECTIVE LAMPS AND CONTAINING ALTERNATED OPAQUE AND TRANSPARENT INDIVIDUAL ANNULAR ZONES IN PREDETERMINED CODED RELATION TO PRODUCE A DIGITAL ELECTRICAL SIGNAL IN SAID DEVICES IN ACCORDANCE WITH THE ANGULAR POSITION OF SAID CODE DISC; EACH OF SAID LIGHT SOURCES, TOGETHER WITH AN ASSOCIATED PHOTO-ELECTRIC DEVICE, BEING AT DIFFERENT ANGULAR POSITIONS AROUND SAID RADIAL ARRAY; SAID PHOTO-ELECTRIC DEVICES TOGETHER WITH THEIR ASSOCIATED MASK APERTURES EACH HAVING DIFFERENT RADIAL POSITIONS AT SUBSTANTIALLY EQUAL INCREMENTS WITH RESPECT TO THE ENCODER AXIS AS WELL AS DIFFERENT ANGULAR ORIENTATIONS ABOUT THE AXIS, AND THE CODED ANNULAR ZONES FOR THE RESPECTIVE DEVICES BEING ANGULARLY ROTATED BY AN AMOUNT EQUAL TO PROVIDE READ-OUT DIGITAL THEIR ASSOCIATED LIGHT SOURCE TO PROVIDE READ-OUT DIGITAL SIGNALS IN THE DEVICES EQUIVALENT TO AN IN-LINE ORIENTATION THEREOF.