Code reading method and apparatus

Claim 2

Code read-out apparatus comprising, in combination, a code carrier in the form a plate of non-magnetic material; clock indicia on one surface of said plate and in the form of uniformly spaced concentric bands of magnetic material; signal indicia on the other surface of said plate and in the form of selectively spaced concentric bands of magnetic material each opposite a different respective clock indicia; means providing a detection path for movement of said code carrier therealong; a pair of magnetic pick-up heads disposed at a point on said path in opposing relation to each other and aligned on the center locus of points generated by center of said concentric bands moving along said path, whereby each magnetic pick-up head is operable to scan across a respective opposite surface of said code carrier in any direction to detect indicia on the associated code carrier surface; and circuit means connected to both said pick-up heads and operable, responsive to simultaneous detection of indicia on both surfaces of said carrier by said pick-up heads, to provide an output pulse corresponding to the detected signal indicia.

Claim 3

Code read-out apparatus, as claimed in claim 5, in which said code carrier is circular plate of non-magnetic material; said clock indicia being in the form of concentric. uniformly spaced annular bands of magnetic material, and said signal indicia being in the form of concentric, selectively spaced annular bands of magnetic material each opposite a different respective clock indicia.

Claim 4

Code read-out apparatus, as claimed in claim 2, in which both surfaces of said plate are formed with concentric uniformly spaced annular channels; said bands of magnetic material being imbedded in said channels.

Claim 5

Code read-out apparatus, as claimed in claim 1, in which said circuit means comprises a pair of shaping circuits each having its input connected to a different respective one of said magnetic pick-up heads; and an AND circuit having its inputs each connected to a different respective one of said shaping circuits.

Claim 6

Code read-out apparatus, as claimed in claim 4, in which said circuit means includes an OR circuit having each of its inputs connected to a different respective one of said shaping circuits.

Claim 7

A code read-out method comprising the steps of providing a code carrier in the form of a plate of non-magnetic material; providing, on one surface of the plate, a number of clock indicia in the form of uniformly spaced concentric first bands of magnetic material having a permeability differing from that of the plate; providing, on the other surface of the plate, a lesser number of signal indicia in the form of selectively spaced concentric second bands of magnetic material, having a permeability differing from that of the plate, each opposite a different preselected respective first band; passing the code carrier bodily along an elongated detEction path; at a point on the path and aligned on the locus of points generated by the center of said concentric bands of magnetic material moving along said path, separately and independently magnetically scanning across both surfaces of the plate simultaneously, to detect successively only the presence or absence of magnetic material bands on the respective plate surfaces by detecting the difference in permeability between the plate and the bands; responsive only to simultaneous detection of aligned first and second magnetic material bands on opposite surfaces of the plate, providing output pulses each corresponding to a detected signal indicia second magnetic material band; and, responsive to detection of either a first or second magnetic material band, providing output clock pulses.

Claim 8

A code read-out method comprising the steps of providing a code carrier in the form of a plate of non-magnetic material; providing, on one surface of the plate, a number of clock indicia in the form of uniformly spaced concentric first bands of magnetic material having a permeability differing from that of the plate; providing, on the other surface of the plate, a lesser number of signal indicia in the form of selectively spaced concentric second bands of magnetic material, having a permeability differing from that of the plate, each opposite a different preselected respective first band; passing the code carrier bodily along an elongated detEction path; at a point on the path and aligned on the locus of points generated by the center of said concentric bands of magnetic material moving along said path, separately and independently magnetically scanning across both surfaces of the plate simultaneously, to detect successively only the presence or absence of magnetic material bands on the respective plate surfaces by detecting the difference in permeability between the plate and the bands; responsive only to simultaneous detection of aligned first and second magnetic material bands on opposite surfaces of the plate, providing output pulses each corresponding to a detected signal indicia second magnetic material band; and, responsive to detection of either a first or second magnetic material band, providing output clock pulses.

Claim 9

Code read-out apparatus comprising, in combination, a code carrier in the form of a plate of non-magnetic material; a number of clock indicia on one surface of said plate and in the form of uniformly spaced concentric first bands of magnetic material; having a permeability differing from that of the plate; a lesser number of signal indicia on the other surface of said plate and in the form of selectively spaced concentric second bands of magnetic material, having a permeability differing from that of the plate, each opposite a different respective preselected first band; means providing an elongated detection path for movement of said code carrier bodily therealong; a pair of magnetic pick-up heads disposed at a point on said path in opposing relation to each other and aligned on the the the locus of points generated by the center of said concentric bands moving along said path, each magnetic pick-up head being operable independently to scan a respective opposite surface of said code carrier to detect successively only the presence or absence of indicia bands on the associated code carrier surface, by detecting the difference in permeability between the plate and the bands; and circuit means connected to both said pick-up heads and operable, responsive only to simultaneous detection of aligned first and second bands on respective opposite surfaces of said carrier by said pick-up heads, to provide output pulses each corresponding to a detected signal indicia second band.

Claim 10

Code read-out apparatus comprising, in combination, a code carrier in the form of a plate of non-magnetic material; a number of clock indicia on one surface of said plate and in the form of uniformly spaced concentric first bands of magnetic material; having a permeability differing from that of the plate; a lesser number of signal indicia on the other surface of said plate and in the form of selectively spaced concentric second bands of magnetic material, having a permeability differing from that of the plate, each opposite a different respective preselected first band; means providing an elongated detection path for movement of said code carrier bodily therealong; a pair of magnetic pick-up heads disposed at a point on said path in opposing relation to each other and aligned on the the the locus of points generated by the center of said concentric bands moving along said path, each magnetic pick-up head being operable independently to scan a respective opposite surface of said code carrier to detect successively only the presence or absence of indicia bands on the associated code carrier surface, by detecting the difference in permeability between the plate and the bands; and circuit means connected to both said pick-up heads and operable, responsive only to simultaneous detection of aligned first and second bands on respective opposite surfaces of said carrier by said pick-up heads, to provide output pulses each corresponding to a detected signal indicia second band.

Claim 11

Code read-out apparatus, as claimed in claim 7, in which both surfaces of said plate are formed with uniformly spaced channels; said bands of magnetic material being imbedded in said channels.

Claim 12

Code read-out apparatus comprising, in combination, a code carrier in the form of a circular plate of non-magnetic material; a number of clock indicia on one surface of said plate and in the form of uniformly spaced concentric first annular bands of magnetic material having a permeability differing from that of the plate; a lesser number of signal indicia on the other surface of said plate and in the form of selectively spaced concentric second annular bands of magnetic material, having a permeability differing from that of the plate, each opposite a different respective preselected first annular band; means providing an elongated detection path for movement of said code carrier bodily therealong; a pair of magnetic pick-up heads disposed at a point on said path in opposing relation to each other and aligned on the the the locus of points generated by the center of said concentric bands moving along said path, each magnetic pick-up head being operable independently to scan a respective opposite surface of said code carrier to detect successively only the presence or absence of indicia bands on the associated code carrier surface, by detecting the difference in permeability between the plate and the bands; a pair one shaping circuits each having its input connected to a different respective ne of said magnetic pick-up heads; an AND circuit having its inputs each connected to a different respective one of said shaping circuits to provide, responsive only to simultaneous detection of aligned first and second bands on reSpective opposite surfaces of said carrier by said pick-up heads, to provide output pulses each corresponding to a detected signal indicia second band; and an OR circuit having each of its inputs connected to a different respective one of said shaping circuits and providing output clock pulses responsive to detection of either a first or second band by said pick-up heads.

Claim 13

Code read-out apparatus comprising, in combination, a code carrier in the form of a circular plate of non-magnetic material; a number of clock indicia on one surface of said plate and in the form of uniformly spaced concentric first annular bands of magnetic material having a permeability differing from that of the plate; a lesser number of signal indicia on the other surface of said plate and in the form of selectively spaced concentric second annular bands of magnetic material, having a permeability differing from that of the plate, each opposite a different respective preselected first annular band; means providing an elongated detection path for movement of said code carrier bodily therealong; a pair of magnetic pick-up heads disposed at a point on said path in opposing relation to each other and aligned on the the the locus of points generated by the center of said concentric bands moving along said path, each magnetic pick-up head being operable independently to scan a respective opposite surface of said code carrier to detect successively only the presence or absence of indicia bands on the associated code carrier surface, by detecting the difference in permeability between the plate and the bands; a pair one shaping circuits each having its input connected to a different respective ne of said magnetic pick-up heads; an AND circuit having its inputs each connected to a different respective one of said shaping circuits to provide, responsive only to simultaneous detection of aligned first and second bands on reSpective opposite surfaces of said carrier by said pick-up heads, to provide output pulses each corresponding to a detected signal indicia second band; and an OR circuit having each of its inputs connected to a different respective one of said shaping circuits and providing output clock pulses responsive to detection of either a first or second band by said pick-up heads.