Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
235 words
An inductive reading device for reading data in the form of metallic information elements located in a predetermined arrangement on a nonconductive card-shaped data carrier, said reading device comprising: at least one reading unit, each unit including transmitting coil means for generating an alternating magnetic field and two receiving coil means spatially arranged so that said transmitting coil means induces voltages of substantially the same amplitudes and phases in said two receiving coil means, said transmitting coil means located opposite said two receiving coil means with a gap therebetween through which said data carrier elements are passed, said two receiving coil means electrically coupled to bridge circuit means which is tuned to generate a substantially zero magnitude output signal when a ferromagnetic metallic element is not between said transmitting and said receiving coil means, said bridge circuit means generating an output signal of a finite magnitude when a ferromagnetic metallic element is placed between said transmitting and said receiving coil means offset toward one of said two receiving coil means by, said magnetic field causing a short-circuit current to flow in said element to induce voltages of unequal amplitudes or phases in said two receiving coil means by increasing the amplitude of the voltage in one of said two receiving coil means and decreasing the amplitude of the voltage in the other one of said two receiving coil means to detune said bridge circuit means.
Claim 2
Dependent Claim
235 words
An inductive reading device for reading data in the form of metallic information elements located in a predetermined arrangement on a nonconductive card-shaped data carrier, said reading device comprising: at least one reading unit, each unit including transmitting coil means for generating an alternating magnetic field and two receiving coil means spatially arranged so that said transmitting coil means induces voltages of substantially the same amplitudes and phases in said two receiving coil means, said transmitting coil means located opposite said two receiving coil means with a gap therebetween through which said data carrier elements are passed, said two receiving coil means electrically coupled to bridge circuit means which is tuned to generate a substantially zero magnitude output signal when a ferromagnetic metallic element is not between said transmitting and said receiving coil means, said bridge circuit means generating an output signal of a finite magnitude when a ferromagnetic metallic element is placed between said transmitting and said receiving coil means offset toward one of said two receiving coil means by, said magnetic field causing a short-circuit current to flow in said element to induce voltages of unequal amplitudes or phases in said two receiving coil means by increasing the amplitude of the voltage in one of said two receiving coil means and decreasing the amplitude of the voltage in the other one of said two receiving coil means to detune said bridge circuit means.
Claim 3
Dependent Claim
97 words
A reading device as claimed in claim 1 further including: a multiple number of said reading units spatially arranged next to one another, said transmitting and receiving coil means of each unit having a central axis with each pair of receiving coil means having their axes offset substantially equidistant from said transmitting coil means axis, said data carrier elements being passed between the coil means of each unit one at a time; and control means to actuate said reading units in a predetermined time sequence to scan the information content of a series of said information elements.
Claim 4
Dependent Claim
78 words
A data carrier to be inductively read by coupling a magnetic field across the carrier, said carrier comprising: a nonconductive layer of material; a multiple number of ring-shaped electromagnetic metallic elements arranged on said nonconductive material, one element in each data location; and two inductively readable orientation marks spatially arranged on said carrier both laterally and longitudinally offset from one another for making the particular one of four possible positions of said carrier recognizable when being inductively read.
Claim 5
Dependent Claim
78 words
A data carrier to be inductively read by coupling a magnetic field across the carrier, said carrier comprising: a nonconductive layer of material; a multiple number of ring-shaped electromagnetic metallic elements arranged on said nonconductive material, one element in each data location; and two inductively readable orientation marks spatially arranged on said carrier both laterally and longitudinally offset from one another for making the particular one of four possible positions of said carrier recognizable when being inductively read.
Claim 6
Dependent Claim
39 words
A data carrier as claimed in claim 3 wherein: each of said ring-shaped elements includes a narrow cross-bar portion adapted to be easily removed to separate said ring; and said elements are arranged in a multiple number of rows.
Claim 7
Dependent Claim
39 words
A data carrier as claimed in claim 4 further including: two control tracks arranged substantially parallel to said element rows, each of said tracks including means for making the moving direction of said carrier recognizable when being inductively read.