Optical encoder

Claim 1

AN OPTICAL ENCODER COMPRISING A LIGHT SOURCE, A CODE DISC ROTATABLY MOUNTED CONFRONTING THE LIGHT SOURCE HAVING A PLURALITY OF CIRCULAR COAXIAL TRACKS WITH ALTERNATE OPAQUE AND TRANSPARENT SECTORS, EACH TRACK HAVING TWO COAXIAL PORTIONS, ONE OF SAID PORTIONS BEING A RADIALLY INWARD PORTION COMPRISING A PLURALITY OF OPAQUE AND TRANSPARENT SECTORS DISPOSED BETWEEN RADII OF THE DISC SEPARATED BY EQUAL ANGLES AND THE OTHE OF SAID PORTIONS BEING A RADIALLY OUTWARD PORTION COMPRISING A PLURALITY OF ALTERNATE TRANSPARENT AND OPAQUE SECTORS DISPOSED BETWEEN THE SAME RADII OF THE DISC, EACH TRANSPARENT SECTOR OF EACH PORTION OF TRACK BEING DISPOSED IN THE SAME RADIAL SECTOR OF THE CODE DISC AS AN OPAQUE SECTOR OF THE OTHER PORTION OF THE TRACK, A PAIR OF LIGHT RESPONSIVE CELLS MOUNTED ON THE SIDE OF THE CODE DISC OPPOSITE THE SOURCE CONFRONTING EACH TRACK OF THE CODE DISC, EACH OF SAID CELLS CONFRONTING THE DISC WITH ONE OF THE CELLS CONFRONTING A TRTANSPARENT SECTOR AND THE OTHER AN OPAQUE SECTOR, AN OPAQUE MEMBER DEFINING A TRANSPARENT SLIT PARALLEL TO A RADIUS OF THE CODE DISC DISPOSED BETWEEN EACH OF THE CELLS AND THE CODE DISC,THE WIDTH OF THE SLIT BEING GREATER THAN ONE-HALF THE LENGTH OF THE SMALLEST RADIAL SECTOR OF THE TRACK OF THE CODE DISC CONFRONTING SAID SLIT, WHEREIN THE PHOTOCELLS ARE DISPOSED ON AN AXIS AND COMPRISE AN ASSEMBLY HAVING A BASE PLATE OF ELECTRICALLY INSULATING MATERIAL, A FIRST AND A SECOND ELECTRICALLY CONDUCTING STRIP DISPOSED ON THE BASE PLATE ON OPPOOSITE SIDES OF THE AXIS OF THE PHOTOCELLS, AND SPACED FROM EACH OTHER, EACH PAIR OF PHOTOCELLS CONFRONTING A TRACK OF THE CODE DISC, A FIRST LEG OF ELECTRICALLY CONDUCTING MATERIAL DISPOSED ON THE BASE PLATE, EXTENDING FROM THE FIRST STRIP, AND TERMINATING ADJACENT TO THE AXIS OF THE PHOTOCELLS, A SECOND LEG OF ELECTRICALLY CONDUCTING MATERIAL DISPOSED ON THE BASE PLATE, EXTENDING FROM THE SECOND STRIP, AND TERMINATING ADJACENT TO THE AXIS OF THE PHOTOCELLS, THE SECOND LEG BEING SPACED FROM THE FIRST LEG ALONG THE AXIS BY THE DISTANCE BETWENE THE PAIR OF CONFRONTING TRACKS OF THE CODE DISC, AN ELECTRICALLY CONDUCTING TERMINAL MEMBER DISPOSED ON THE BASE PLATE HAVING A FIRST PORTION DISPOSED ON THE SIDE OF THE PHOTOCELL AXIS OPPOSITE THE FIRST LEG AND CONFRONTINGLY SPACED THEREFROM, A SECOND PORTION DISPOSED ON THE SIDE OF THE PHOTOCELL AXIS OPPOSITE THE SECOND LEG AND CONFRONTINGLY SPACED THEREFROM, AND AN ELECTRICALLY CONDUCTING BAR EXTENDING BETWEEN THE FIRST AND SECOND PORTIONS AND ACROSS THE AXISBETWEN THE FIRST AND SECOND LEGS, AMASS OF SEMI-CONDUCTING MATERIAL DISPOSED BETWEEN THE FIRST LEG AND THE FIRST PORTION OF THE TERMINAL MEMBER, A SECOND MASS OF SEMICONDUCTING MATERIAL DISPOSED BETWEEN THE SECOND LEG AND THE SECOND PORTION OF THE TERMINAL MEMBER, AND MEANS FOR SAMPLING THE POSITION OF THE CODE DISC DURING A TIME PERIOD SHORT COMPAARED WITH THE MINIMUM TIME REQUIRED FOR A SECTOR OF THE CODE DISC TO ROTATE PAST THE SLIT INCLUDING AN ELECTRICALLY RESPONSIVE DEVICE HAVING A TRIGGERING THRESHOLD AND AN INPUT CIRCUIT COUPLED TO EACH OF THE CELLS.