Coded arrangement of inductively detectable electrical conducting segments

Claim 2

In a system for reading an encoded record, comprising: a plurality of nonmagnetic electrically conductive segments for conducting eddy currents, each of said segments being electrically separate, said segments being positioned in a coded arrangement; electrical insulating means for holding said segments in said coded arrangement; means for detecting the coded arrangement of saId segments, said detecting means including a coil for inducing eddy currents in said segments, said detecting means being responsive to said eddy currents for indicating the presence of a segment; and magnetic flux shielding means between said coil and said segments, said shielding means defining a window through which flux from said coil extends to said segments.

Claim 3

The system of claim 1 wherein said plurality of segments are metallic foil, and said insulating means is a backing to which said segments are secured.

Claim 4

The system of claim 2 wherein said insulating means and metalic foil are secured between opaque electrical insulation laminae for visibly obscuring said segments.

Claim 5

The system of claim 1 wherein said magnetic flux shielding means is nonmagnetic electrically conducting foil.

Claim 6

In a system for reading an encoded record, comprising: a plurality of nonmagnetic electrically conductive segments for conducting eddy currents, each of said segments being electrically separate, said segments being positioned in a coded arrangement; electrical insulating means for holding said segments in said coded arrangement; means for detecting the coded arrangement of said segments, said detecting means including means for inducing eddy currents in said segments, said inducing means being responsive to said eddy currents for indicating the presence of a segment, said inducing means including an oscillator circuit having a coil for inducing eddy currents in said segments, said oscillator circuit being responsive to said eddy currents for reducing the oscillating power in said oscillator circuit; and magnetic flux shielding means between said coil and said segments, said shielding means defining a window through which flux from said coil extends to said segments.

Claim 7

In a system for reading an encoded record, comprising: a plurality of nonmagnetic electrically conductive segments for conducting eddy currents, each of said segments being electrically separate, said segments being positioned in a coded arrangement; electrical insulating means for holding said segments in said coded arrangement; means for detecting the coded arrangement of said segments, said detecting means including means for inducing eddy currents in said segments, said inducing means being responsive to said eddy currents for indicating the presence of a segment, said inducing means including an oscillator circuit having a coil for inducing eddy currents in said segments, said oscillator circuit being responsive to said eddy currents for reducing the oscillating power in said oscillator circuit; and magnetic flux shielding means between said coil and said segments, said shielding means defining a window through which flux from said coil extends to said segments.

Claim 8

The system of claim 5 wherein said magnetic flux shielding means is nonmagnetic electrically conducting foil.

Claim 9

In a system for reading an encoded record, comprising: a plurality of nonmagnetic electrically conductive segments for conducting eddy currents, each of said segments being electrically separate, said segments being positioned in a coded arrangement; electrical insulating means for holding said segments in said coded arrangement; and means for detecting the coded arrangement of said segments, said detecting means including means for inducing eddy currents in said segments, said eddy-current-inducing means including an oscillator circuit having a first coil for successively inducing eddy currents in successive ones of said segments, said oscillator being operable for normally producing oscillations of a constant amplitude; said detecting means being responsive to said eddy currents for generating a first series of pulses corresponding to the coding of said segments, each of said pulses originating in said first coil.

Claim 10

In a system for reading an encoded record, comprising: a plurality of nonmagnetic electrically conductive segments for conducting eddy currents, each of said segments being electrically separate, said segments being positioned in a coded arrangement; electrical insulating means for holding said segments in said coded arrangement; and means for detecting the coded arrangement of said segments, said detecting means including means for inducing eddy currents in said segments, said eddy-current-inducing means including an oscillator circuit having a first coil for successively inducing eddy currents in successive ones of said segments, said oscillator being operable for normally producing oscillations of a constant amplitude; said detecting means being responsive to said eddy currents for generating a first series of pulses corresponding to the coding of said segments, each of said pulses originating in said first coil.

Claim 11

The system of claim 7 wherein said detecting means further includes a rectifier connected to said oscillator for producing a first voltage level responsive to normal oscillations in said oscillator and for producing a second voltage level responsive to oscillations of reduced power when one of said segments is adjacent to said coil.

Claim 12

The system of claim 8, wherein said detecting means further includes means for transmitting said first and second voltage levels of said rectifier over a single line to a means for comparing said voltage levels with stored information and transmitting an output signal responsive to the comparison of said voltage levels and said stored information, and means actuated by said output signal.

Claim 13

The system of claim 7 wherein said segments are arranged in a column, said coil is aligned with said segments, said detecting means being responsive to movement of each segment past said coil for generating a corresponding output pulse, a series of asynchronous pulses being generated upon movement of all said segments part said coil, said coil being driven by said oscillator at a frequency that provides a plurality of pEriods of oscillation during movement of each segment past said coil.

Claim 14

The system of claim 10 wherein the frequency of said oscillations are in the range of 2 MHz.

Claim 15

The system of claim 7 further including a second plurality of electrically conductive segments, said detecting means including a second coil for successively inducing eddy currents in successive ones of said second plurality of segments, said detecting means being responsive to eddy currents in said second plurality of segments for generating a second series of pulses corresponding to the coding of said second plurality of segments, each pulse of said second series originating in said second coil.

Claim 16

The system of claim 2 wherein said detecting means includes means for applying said first and second series of pulses to a single line for transmission to a utilization device.