Inductive coin validation system and payphone using such system
First Claim
1. Coin validation apparatus comprising:
- a) a coin guide for guiding an input coin along a predetermined coin path with one face of the input coin resting on a side wall of the coin guide;
b) at least one inductive sensor arranged to generate a magnetic field at a position along the coin path, for detecting a dimension of the input coin by interaction with the input coin;
c) circuit means for detecting an effect of the input coin on an inductance of the inductive sensor and making a decision whether the input coin is a predetermined coin or one of a predetermined set of coins;
d) at least a part of the side wall of the coin guide comprising a circuit board bearing at least one set of contact pads for surface-mounting a component thereto, and electrically conductive tracks for connecting the contact pads to one of other components on the circuit board and connection points for electrical connection to components not on the circuit board; and
e) the inductive sensor comprising an inductor surface-mounted to the at least one set of contact pads.
4 Assignments
0 Petitions
Accused Products
Abstract
A coin validation arrangement, usable for example in pay telephones, uses one or more inductive sensors having a small effective magnetic field so that the inductive sensor responds only to the material of a strip across the coin. Preferably a plurality of inductive sensors are used, mounted at different heights above the floor of a coin guide, at different positions along the coin path. At each position along the coin path there may be either one or a plurality of inductive sensors. Preferably the inductive sensors are surface mount inductors on a printed circuit board which forms part of one wall of the coin guide. Such arrangements are particularly useful for recognizing coins having an outer ring made of a different material from the central disc, and for distinguishing such coins from uniform composition coins.
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Citations
49 Claims
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1. Coin validation apparatus comprising:
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a) a coin guide for guiding an input coin along a predetermined coin path with one face of the input coin resting on a side wall of the coin guide;
b) at least one inductive sensor arranged to generate a magnetic field at a position along the coin path, for detecting a dimension of the input coin by interaction with the input coin;
c) circuit means for detecting an effect of the input coin on an inductance of the inductive sensor and making a decision whether the input coin is a predetermined coin or one of a predetermined set of coins;
d) at least a part of the side wall of the coin guide comprising a circuit board bearing at least one set of contact pads for surface-mounting a component thereto, and electrically conductive tracks for connecting the contact pads to one of other components on the circuit board and connection points for electrical connection to components not on the circuit board; and
e) the inductive sensor comprising an inductor surface-mounted to the at least one set of contact pads. - View Dependent Claims (2, 3, 4, 5, 6, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 43, 44, 45)
a) wherein the size of the effective magnetic field of the inductive sensor is defined as a maximum distance, in a height direction of the coin guide, between points in a plane of measurement where the magnetic field has a strength which falls to 50% of its maximum field strength within the plane of measurement, b) wherein the height direction of the coin guide is defined as a direction perpendicular to a direction of the coin path and parallel to the plane of measurement, and c) wherein the plane of measurement is defined as a plane of the one face of the input coin which rests on said side wall of the coin guide. -
5. Coin validation apparatus according to claim 1, in which the effective magnetic field of the inductive sensor has a width which is no more than 12 mm, and
a) wherein the width of the effective magnetic field is defined as a maximum distance, in a direction along the coin path, between points in a plane of measurement where the magnetic field has a strength which falls to 50% of its maximum field strength within the plane of measurement. -
6. Coin validation apparatus according to claim 1, in which the effective magnetic field of the inductive sensor has a size which is less than half of a diameter of the predetermined coin or of a smallest coin of the predetermined set of coins,
a) wherein the size of the effective magnetic field of the inductive sensor is defined as a maximum distance, in a height direction of the coin guide, between points in a plane of measurement where the magnetic field has a strength which falls to 50% of its maximum field strength within the plane of measurement, b) wherein the height direction of the coin guide is defined as a direction perpendicular to a direction of the coin path and parallel to the plane of measurement, and c) wherein the plane of measurement is defined as a plane of the one face of the input coin which rests on said side wall of the coin guide. -
21. Coin validation apparatus according to claim 1, in which there are a plurality of said inductive sensors arranged to generate respective magnetic fields at different positions in a height direction of the coin guide from one other and at different positions along the coin path from one another.
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22. Coin validation apparatus according to claim 1, in which there are a plurality of said inductive sensors arranged to generate respective magnetic fields at different positions in a height direction of the coin guide from one other and at the same position along the coin path as one another.
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23. Coin validation apparatus according to claim 1, in which the inductive sensor is mounted on said side wall of the coin guide.
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24. Coin validation apparatus according to claim 1, in which the coin guide comprises a second side wall, on the other side of the coin path from the first-mentioned side wall, and at least one further said inductive sensor is mounted on said second side wall.
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25. Coin validation apparatus according to claim 1, further comprising an insertion slot through which input coins are input to the coin path, and at least one said inductive sensor being arranged to generate its magnetic field at a position spaced above a floor of the coin guide in a height direction by no more than 90% of a diameter of the largest diameter input coin which can be inserted through the insertion slot and guided along the coin path.
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26. Coin validation apparatus according to claim 25, in which said position is spaced above the floor of the coin guide by no more than 80% of said diameter.
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27. Coin validation apparatus according to claim 25, in which said position is spaced above the floor of the coin guide by no more than 70% of said diameter.
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28. Coin validation apparatus according to claim 25, in which said position is spaced above the floor of the coin guide by at least 10% of said diameter.
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29. Coin validation apparatus according to claim 25, in which said position is spaced above the floor of the coin guide by at least 20% of said diameter.
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30. Coin validation apparatus according to claim 25, in which said position is spaced above the floor of the coin guide by at least 30% of said diameter.
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31. Coin validation apparatus according to claim 1, in which the circuit means comprises means for causing an electric current in the inductive sensor to oscillate at an oscillation frequency, and thereby to cause the magnetic field to oscillate.
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32. Coin validation apparatus according to claim 31, in which the oscillation frequency, in the absence of the input coin, is greater than 100 kHz.
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33. Coin validation apparatus according to claim 31, in which the oscillation frequency, in the absence of the input coin, is less than 75 kHz.
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34. Coin validation apparatus according to claim 31, in which the oscillation frequency, in the absence of the input coin, is less than 20 kHz.
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35. Coin validation apparatus according to claim 31, in which the oscillation frequency, in the absence of the input coin, is about 10 kHz.
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36. Coin validation apparatus according to claim 31, in which the circuit means comprises an oscillator connected to the inductive sensor so that a change in the inductance of the inductive sensor causes a change in the oscillation frequency of the oscillator, and the circuit means further comprises an analysis circuit for detecting and analyzing changes in the oscillation frequency in order to make said decision.
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37. Coin validation apparatus according to claim 36 in which the analysis circuit is operative for counting a number of oscillations of the oscillator occurring in a predetermined period of time, or measuring the time taken for a predetermined number of oscillations of the oscillator to occur.
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38. Coin validation apparatus according to claim 36, in which
a) at least one capacitive sensor having a capacitance is provided to interact with the input coin, so as to affect the capacitance, at a position along the coin path, b) the oscillator is operative for outputting a first oscillating signal at the oscillation frequency, c) a second oscillator is provided for outputting a second oscillating signal, the second oscillator being connected to the at least one capacitive sensor so that a change in the capacitance of the capacitive sensor causes a change in the oscillation frequency of the second oscillating signal, the oscillation frequency of the second oscillating signal in the absence of the input coin being greater than the oscillation frequency of the first oscillating signal in the absence of the input coin, and d) the analysis circuit comprises: -
i) a first counter for counting repeatedly a predetermined number of oscillations of the first oscillating signal to determine durations of a plurality of sample periods;
ii) a second counter for counting a number of oscillations of the second oscillating signal occurring in each said sample period to obtain count values; and
iii) decision means for making the decision on the basis of the count values counted by the second counter.
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43. Coin validation apparatus according to claim 1, in which the circuit means measures a peak change in the inductance of the inductive sensor caused by the input coin, and compares the peak change with a pre-stored table of reference values in order to make said decision.
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44. Coin validation apparatus according to claim 1, in which the circuit means measures a parameter of a shape of a curve of the inductance of the inductive sensor against time, caused by the effect of the input coin on the inductive sensor, and compares the parameter with a table of pre-stored values in order to make said decision.
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45. Coin validation apparatus according to claim 1, in which the circuit means comprises a neural network for making said decision.
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7. Coin validation apparatus comprising:
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a) a coin guide for guiding an input coin along a predetermined coin path with one face of the input coin resting on a side wall of the coin guide;
b) at least one inductive sensor arranged to generate a magnetic field at a position along the coin path, for detecting a dimension of the input coin by interaction with the input coin;
c) circuit means for measuring a magnitude of an effect of the input coin on an inductance of the inductive sensor and making a decision whether the input coin is a predetermined coin or one of a predetermined set of coins;
d) the effective magnetic field of the inductive sensor having a size which is no more than 12 mm;
e) the size of the effective magnetic field of the inductive sensor being defined as a maximum distance, in a height direction of the coin guide, between points in a plane of measurement where the magnetic field has a strength which falls to 50% of its maximum field strength within the plane of measurement;
f) the height direction of the coin guide being defined as a direction perpendicular to a direction of the coin path and parallel to the plane of measurement; and
g) the plane of measurement being defined as a plane of the one face of the input coin which rests on said side wall of the coin guide. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
wherein the width of the effective magnetic field is defined as the maximum distance, in the direction along the coin path, between the points in the plane of measurement where the magnetic field strength falls to 50% of its maximum field strength within the plane of measurement. -
12. Coin validation apparatus according to claim 11, in which the width of the effective magnetic field of the inductive sensor is no more than 8 mm.
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13. Coin validation apparatus according to claim 11, in which the width of the effective magnetic field of the inductive sensor is no more than 6 mm.
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14. Coin validation apparatus according to claim 11, in which the width of the effective magnetic field of the inductive sensor is no more than 5 mm.
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15. Coin validation apparatus comprising:
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a) a coin guide for guiding an input coin along a predetermined coin path with one face of the input coin resting on a side wall of the coin guide;
b) at least one inductive sensor arranged to generate a magnetic field at a position along the coin path, for detecting a dimension of the input coin by interaction with the input coin;
c) circuit means for measuring a magnitude of an effect of the input coin on an inductance of the inductive sensor and making a decision whether the input coin is a predetermined coin or one of a predetermined set of coins;
d) the effective magnetic field of the inductive sensor having a size which is less than half of a diameter of the predetermined coin or of the smallest coin of the predetermined set of coins;
e) the size of the effective magnetic field of the inductive sensor being defined as a maximum distance, in a height direction of the coin guide, between points in a plane of measurement where the magnetic field has a strength which falls to 50% of its maximum field strength within the plane of measurement;
f) the height direction of the coin guide being defined as a direction perpendicular to a direction of the coin path and parallel to the plane of measurement; and
g) the plane of measurement being defined as the plane of the one face of the input coin which rests on said side wall of the coin guide. - View Dependent Claims (16, 17, 18, 19, 20)
a) wherein the width of the effective magnetic field is defined as the maximum distance, in the direction along the coin path, between the points in the plane of measurement where the magnetic field strength falls to 50% of its maximum field strength within the plane of measurement. -
19. Coin validation apparatus according to claim 18, in which the width of the effective magnetic field is less than a third of said diameter.
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20. Coin validation apparatus according to claim 18, in which the width of the effective magnetic field is less than a quarter of said diameter.
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39. Coin validation apparatus comprising:
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a) a coin guide for guiding an input coin along a predetermined coin path;
b) at least one inductive sensor having an inductance arranged to generate an oscillating magnetic field, for interaction with the input coin, at a first position along the coin path;
c) at least one capacitive sensor having a capacitance arranged to interact with the input coin, so as to affect the capacitance, at a second position along the coin path; and
d) circuit means for responding to an effect of the input coin on the inductance of the at least one inductive sensor and the capacitance of the at least one capacitive sensor and making a decision whether the input coin is a predetermined coin or one of a predetermined set of coins, the circuit means comprising;
i) a first oscillator circuit, connected to the at least one inductive sensor for passing an alternating current therethrough, and for outputting a first oscillating signal having a frequency which varies with variation in the inductance of the at least one inductive sensor, ii) an analysis circuit for counting oscillations of the first oscillating signal and for making the decision, iii) a second oscillator circuit, connected to the at least one capacitive sensor for passing an alternating current therethrough and for outputting a second oscillating signal having a frequency which varies with variation in the capacitance of the at least one capacitive sensor, the frequency of the second oscillating signal in the absence of the input coin being greater than the frequency of the first oscillating signal in the absence of the input coin, and iv) the analysis circuit comprising;
(a) a first counter for counting repeatedly a predetermined number of oscillations of the first oscillating signal to determine durations of a plurality of sample periods;
(b) a second counter for counting a number of oscillations of the second oscillating signal occurring in each said sample period to obtain count values; and
(c) decision means for making the decision on the basis of the count values counted by the second counter. - View Dependent Claims (40, 41, 42)
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46. A pay telephone, comprising:
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a coin validation apparatus including a) a coin guide for guiding an input coin along a predetermined coin path with one face of the input coin resting on a side wall of the coin guide;
b) at least one inductive sensor having an inductance and arranged to generate a magnetic field at a position along the coin path, for detecting a dimension of the input coin by interaction with the input coin;
c) circuit means for detecting an effect of the input coin on the inductance of the inductive sensor and making a decision whether the input coin is a predetermined coin or one of a predetermined set of coins;
d) at least a part of the side wall of the coin guide comprising a circuit board bearing at least one set of contact pads for surface-mounting a component thereto, and electrically conductive tracks for connecting the contact pads to one of other components on the circuit board and connection points for electrical connection to components not on the circuit board; and
e) the inductive sensor comprising an inductor surface-mounted to the at least one set of contact pads.
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47. A pay telephone, comprising;
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a coin validation apparatus including a) a coin guide for guiding an input coin along a predetermined coin path with one face of the input coin resting on a side wall of the coin guide;
b) at least one inductive sensor having an inductance and arranged to generate a magnetic field at a position along the coin path, for detecting a dimension of the input coin by interaction with the input coin;
c) circuit means for measuring a magnitude of an effect of the input coin on the inductance of the inductive sensor and making a decision whether the input coin is a predetermined coin or one of a predetermined set of coins;
d) the effective magnetic field of the inductive sensor having a size which is no more than 12 mm;
e) the size of the effective magnetic field of the inductive sensor being defined as a maximum distance, in a height direction of the coin guide, between points in a plane of measurement where the magnetic field has a strength which falls to 50% of its maximum field strength within the plane of measurement;
f) the height direction of the coin guide being defined as a direction perpendicular to a direction of the coin path and parallel to the plane of measurement; and
g) the plane of measurement being defined as a plane of the one face of the input coin which rests on said side wall of the coin guide.
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48. A pay telephone, comprising:
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a coin validation apparatus including a) a coin guide for guiding an input coin along a predetermined coin path with one face of the input coin resting on a side wall of the coin guide;
b) at least one inductive sensor having an inductance and arranged to generate a magnetic field at a position along the coin path, for detecting a dimension of the input coin by interaction with the input coin;
c) circuit means for measuring a magnitude of an effect of the input coin on the inductance of the inductive sensor and making a decision whether the input coin is a predetermined coin or one of a predetermined set of coins;
d) the effective magnetic field of the inductive sensor having a size which is no more than 12 mm;
e) the size of the effective magnetic field of the inductive sensor being defined as a maximum distance, in a height direction of the coin guide, between points in a plane of measurement where the magnetic field has a strength which falls to 50% of its maximum field strength within the plane of measurement;
f) the height direction of the coin guide being defined as a direction perpendicular to a direction of the coin path and parallel to the plane of measurement; and
g) the plane of measurement being defined as a plane of the face of the one input coin which rests on said side wall of the coin guide.
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49. A pay telephone, comprising:
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a coin validation apparatus including a) a coin guide for guiding an input coin along a predetermined coin path;
b) at least one inductive sensor having an inductance and arranged to generate an oscillating magnetic field, for interaction with the input coin, at a first position along the coin path;
c) at least one capacitive sensor having a capacitance and arranged to interact with the input coin, so as to affect the capacitance, at a second position along the coin path;
d) circuit means for responding to an effect of the input coin on the inductance of the at least one inductive sensor and the capacitance of the at least one capacitive sensor and making a decision whether the input coin is a predetermined coin or one of a predetermined set of coins, the circuit means comprising;
i) a first oscillator circuit, connected to the at least one inductive sensor for passing an alternating current therethrough, and for outputting a first oscillating signal having a frequency which varies with variation in the inductance of the at least one inductive sensor, ii) an analysis circuit for counting oscillations of the first oscillating signal and for making the decision, iii) a second oscillator circuit, connected to the at least one capacitive sensor for passing an alternating current therethrough, and for outputting a second oscillating signal having a frequency which varies with variation in the capacitance of the at least one capacitive sensor, and iv) the frequency of the second oscillating signal in the absence of the input coin being greater than the frequency of the first oscillating signal in the absence of the input coin; and
v) the analysis circuit comprising;
(a) a first counter for counting repeatedly a predetermined number of oscillations of the first oscillating signal to determine durations of a plurality of sample periods;
(b) a second counter for counting the number of oscillations of the second oscillating signal occurring in each said sample period to obtain count values; and
(c) decision means for making the decision on the basis of the count values counted by the second counter.
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Specification