Money validation

Details Money validation Money validation

1996-02-12

1998-02-10

Bartuska, F. J.

Check-actuated control mechanisms

Including means to test validity of check

By testing material composition

G07D 508

Patent

active

057159262

DESCRIPTION:

BRIEF SUMMARY
FIELD OF THE INVENTION

This invention relates to a method of, and apparatus for, validating items of money (or like items of value); particularly, but not exclusively, to validating coins.


BACKGROUND OF THE INVENTION

It is known to validate items of money using an inductive sensor affected by an electromagnetic field, by measuring the effects on the sensor of a coin interacting with the field. The sensor may comprise a coil, and the field may be generated by the sensor coil or by another coil close thereto.
It is known to utilise measurements of the real and imaginary (i.e. the resistive and inductive) components of the inductance of the sensor as a basis for validating items of money; as described, for example, in U.S. Pat. No. 5,048,662 or U.S. Pat. No. 4,946,019.
In coin testing apparatus, as is generally known, a coin is subjected to one or more tests by passing it along a pathway in which it enters an oscillating magnetic field produced by an inductor, and measuring the degree of interaction between the coin and the field, the resulting measurement being dependent upon one or more characteristics of the coin. The resulting measurement is then processed (for example compared) with reference data, or each of a set of reference data, corresponding to the measurement obtained from one or more denominations of acceptable coin. It is common to apply more than one such test, the respective tests being responsive to respective different coin characteristics, and to judge the tested coin acceptable only if all the test results are appropriate to a single, acceptable, denomination of coin. An example of such apparatus is described in GB-A-2093620.
Our earlier application GB-A-2254948, and corresponding U.S. Pat. No. 5,213,190, describe a technique which is particularly useful for coin validation. In this technique, a measurement which is primarily sensitive to the coin material is derived by measuring the angle of displacement, in the impedance plane (that is, the plane in Which the reactive impedance and the resistive impedance of a circuit or inductor are represented as measurements or vectors along two mutually perpendicular axes in that plane), of the impedance as a coin passes through the field.


SUMMARY OF THE INVENTION

An object of the present invention is to provide an improved method and apparatus for making impedance plane measurements of a coin.
Another object of the invention is to provide a method and apparatus for impedance plane measurements of a coin using relatively simple and inexpensive hardware to provide an accurate result.
The present invention provides, in one aspect, a method of validating items of money using parameters relating to the real and/or imaginary components of impedance of an inductor affected by the interaction between a magnetic field and the item of money, by measuring the phase of the inductor output using a timer circuit.
In particular, two timing measurements are taken from different parts of the circuit including the inductor, and are combined to derive the real and imaginary components of impedance. Thus, digital timing circuitry may be employed to accurately measure both components of complex impedance, without requiring extensive analogue circuitry for amplitude, frequency or phase measurement.
Other aspects and preferred embodiments of the invention will be apparent from the following description and claims.
The invention will now be described, by way of example only, with reference to the accompanying drawings.


BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic vertical section through a coin validator;
FIG. 2 is a schematic block diagram indicating the electrical arrangement of a money validator according to an embodiment of the present invention;
FIG. 3 is an impedance plane diagram;
FIG. 4 is a block diagram showing in greater detail a part of a signal processing circuit forming part of the embodiment of FIG. 2;
FIG. 5 is a timing diagram showing the voltages at various points of the circuit of FIG. 4 over time;
FIG. 6 is a block diagram showing i

REFERENCES:
patent: 4349095 (1982-09-01), Lewis
patent: 5236071 (1993-08-01), Lee

Affiliated with

Also associated with

Rating

Money validation does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Money validation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Money validation will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2070584