Currency discrimination system and method

Abstract

According to some embodiments of the invention, a magnetic sensor having a track width of greater than about 50 millimeters is provided. The magnetic sensor is adapted to detect a magnetic feature and produce a linear, analog output in response to the magnetic feature. The analog output is along a single data channel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a is a perspective view of an integrated scan head, according to one embodiment of the present invention.

FIG. 1 b is an exploded perspective view of the integrated scan head of FIG. 1a.

FIG. 2 illustrates a banknote including an intermittent-magnetic thread having magnetic and nonmagnetic segments, according to one embodiment of the present invention.

FIG. 3 is a perspective view of a single-pocket currency processing device incorporating the scan head of FIG. 1, according to one embodiment of the present invention.

FIG. 4 is a perspective view of a two-pocket currency processing device incorporating the scan head of FIG. 1, according to another embodiment of the present invention.

FIG. 5 is a side view of the internal compartment of the single-pocket currency processing device of FIG. 3 incorporating the scan head of FIG. 1, according to one embodiment of the present invention.

FIG. 6 a is a functional block diagram of a currency processing device, according to one embodiment of the present invention.

FIG. 6 b is a functional block diagram of a currency processing device, according to another embodiment of the present invention.

FIG. 7 is a flow chart describing the operation of a currency processing device, according to one embodiment of the present invention.

FIGS. 8 a-d illustrate a digitization method for an analog magnetic signal generated by a magnetic sensor sensing a magnetic element, according to one embodiment of the present invention.

FIGS. 9 a-e illustrate a digitization method for an analog magnetic signal generated by a magnetic sensor sensing a magnetic element, according to another embodiment of the present invention.

Claims

1. A document processing device for processing a plurality of documents having a magnetic feature, the document processing device comprising: a magnetization member adapted to create a magnetic field of sufficient strength to magnetize a magnetic feature of each of a plurality of documents;a magnetic sensor having a continuous track width of greater than about 50 millimeters, the magnetic sensor being adapted to produce a linear, analog output signal in response to the plurality of magnetic features moving past the magnetic sensor;a transport mechanism adapted to move the plurality of documents past the magnetization member and the magnetic sensor, the transport mechanism including an encoder adapted to provide positional data;at least one comparator adapted to detect when the analog output of the magnetic sensor exceeds a threshold value; andat least one digital circuit adapted to record the positional data provided by the encoder, the at least one digital circuit recording the positional data in response to the analog output signal of the magnetic sensor exceeding the threshold value.

2. The document processing device of claim 1, wherein the magnetization member is a permanent magnet.

3. The document processing device of claim 1, wherein the magnetization member is an electromagnetic device.

4. The document processing device of claim 1, wherein the magnetization member is adapted to create a constant magnetic field.

5. The document processing device of claim 1, wherein the magnetization member is adapted to create an alternating magnetic field.

6. The document processing device of claim 5, wherein the magnetization member is adapted to encode a pattern on the magnetic feature.

7. The document processing device of claim 6, further comprising a bandpass filter tuned to recognize a frequency of the pattern encoded by the magnetization member into the magnetic feature.

8. The document processing device of claim 1, wherein the magnetic sensor is a magneto-resistive field sensor.

9. The document processing device of claim 1, wherein the magnetic sensor includes a nonmagnetic substrate having a thin-film sensing element deposited thereon.

10. The document processing device of claim 1, wherein the magnetization member is located upstream from the magnetic sensor.

11. The document processing device of claim 1, wherein the magnetic feature is a magnetic thread.

12. The document processing device of claim 1, wherein the magnetic feature is an intermittent-magnetic thread.

13. The document processing device of claim 1, wherein the plurality of documents is a plurality of currency bills.

14. The document processing device of claim 13, wherein the positional data for the magnetic feature is utilized to denominate the currency bills.

15. The document processing device of claim 13, wherein the positional data for the magnetic feature is utilized to authenticate the currency bills.

16. A method for processing a plurality of documents having at least one magnetic feature, the method comprising the acts of: magnetizing the at least one magnetic feature;sensing a flux of each of the plurality of documents, the flux being sensed by a magnetic sensor;generating an analog signal along a single channel, the analog signal being generated by the magnetic sensor as the plurality of documents are in close proximity to the magnetic sensor, the analog signal being representative of the sensed flux;monitoring the generated analog signal along the single channel with at least one comparator to determine whether a threshold voltage has been exceeded; anddigitizing the analog signal by generating an output voltage in response to the threshold voltage being exceeded, the output voltage being independent of the analog signal, the analog signal being digitized without the use of an analog-to-digital converter.

17. The method of claim 16, wherein the magnetizing creates an alternating magnetic field encoding a pattern on the at least one magnetic features.

18. The method of claim 16, wherein the magnetic sensor is a magneto-resistive field sensor.

19. The method of claim 16, wherein the magnetic sensor includes a nonmagnetic substrate having a thin-film sensing element deposited thereon.

20. The method of claim 16, wherein the magnetic feature is a magnetic thread.