EP2960873A1

EP2960873A1 - In-coin passage coin sensing system

Info

Publication number: EP2960873A1
Application number: EP14173693.4A
Authority: EP
Inventors: Tien-Yuan Chien; Dong-Ying Yang; Ruei-Jia Huang
Original assignee: International Currency Technologies Corp
Current assignee: International Currency Technologies Corp
Priority date: 2014-06-24
Filing date: 2014-06-24
Publication date: 2015-12-30

Abstract

A coin acceptor includes a main body having a coin dispenser mounted therein, coin tube disposed at the bottom side of the coin dispenser, and a sensing device including a circuit module having a resonant circuit, sensing coils electrically connected to the resonant circuit and an insulation film sealing the sensing coils and bonded to the periphery of the coin tubes to hold each sensing coil in the periphery of one respective coin tube in such a manner that when one or multiple metal coins are dispensed by the coin dispenser into one coin tube, an alternating magnetic field generated by one respective sensing coil induces eddy currents in the metal coins in the respective coin tube, enabling the circuit module to calculate the quantity of the metal coins in the respective coin tube by measuring the energy loss and change in resonance frequency in the resonant circuit.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention:

The present invention relates to coin detecting technology and more particularly, to an in-coin passage coin sensing system for coin acceptor for use in an automatic vending machine or consumer service system, which uses sensing coils to work with a resonant circuit for enabling the circuit module to calculate the quantity of the metal coins in the respective coin tube by measuring the energy loss and change in resonance frequency in the resonant circuit subject to an equivalent parallel resonance impedance between the metal coins in the respective coin tube and the respective sensing coil.

2. Description of the Related Art:

Following fast development of social civilization and technology, people accelerate their pace of life and require a better quality of life. In consequence, various automatic vending machines are used everywhere to sell different products without serviceman, bringing convenience to people and helping suppliers save much labor cost. Following increasing of selling items, new automatic vending machines with added functions are created.
Further, regular automatic vending machines and game machines commonly use a coin acceptor for receiving coins so that a consumer can insert coins into the automatic vending machine or game machine to purchase commodities or to play games. The coin acceptor of a coin-operated machine generally comprises a recognition module for recognizing the authenticity and value of every inserted coin. Because different coins or tokens are used in different countries or different amusement parks, and because different coins/tokens have different sizes and values, a recognition module must be able to recognize the authenticity and values of different coins/tokens. A coin acceptor further comprises a coin dispenser adapted for sorting coins of different values into different coin tubes, a sensing device adapted for sensing the quantity of coins in each coin tube, and a coin hopper located at the bottom side of the coin tubes for outputting coins. When the quantity of coins in one coin tube reaches a predetermined high level, the sensing device gives a corresponding signal to the control circuit, prohibiting the coin dispenser from sorting any coin into this coin tube. On the contrary, when the quantity of coins in one coin tube reaches a predetermined low level, the sensing device gives a corresponding signal to the control circuit, prohibiting the hopper from outputting coins, ensuring the normal operation of the machine.
Conventional coin acceptors commonly use a non-contact displacement sensor to sense metal coins/tokens. Many different types of non-contact displacement sensors, such as ultrasonic sensors, optical sensors and electromagnetic sensors are commercially available. An ultrasonic sensor uses an ultrasonic transmitter to transmit an ultrasonic wave. When a metal coin passes across the ultrasonic wave, the metal coin absorbs the energy, causing an attenuation of the energy. Thus, the control circuit can calculate the location of the coin subject to the change in the energy. However, an ultrasonic sensor of this design has a large size and high cost. Further, the reflection signal intensity of the ultrasonic sensor is inversely proportional to the distance of the coin. For sensing coins in a relatively longer coin tube, the problems of scattering attenuation, excitation energy insufficiency and signal recognition difficulty can occur.
An optical sensor uses an optical transmitter to transmit light across the coin tube and an optical receiver to receive light that passes across the coin tubes. When coins are accumulated in the coin tube, they block a part of the light that falls upon the coin tubes. Subject to this shading effect, the control circuit can calculate the location of the coins in the coin tubes. An optical sensor has the advantage of low signal attenuation and is free from the interference of electronic noises or variation of coin tube sizes. However, an optical sensor can easily be contaminated by dust, affecting sensing accuracy. Further, the optical components wear quickly with use, lowering its performance and leading to recognition error.
Among conventional non-contact displacement sensors, an electromagnetic sensor is most popularly used for measuring coins in coin tubes in a close distance for the advantages of small size and operability under a high temperature environment or an environment having a high concentration of dust or pollutants. When a metal coin passes over a sensing coil of the electromagnetic sensor, the alternating magnetic field generated by the sensing coil induces an eddy current in the metal coil. Subject to the induced amount of the eddy current, the control circuit can calculate the location of the metal coin. However, the distance between the sensing coil and the metal coin, the geometric shape and magnetic permeability of the metal coin will cause a change in the eddy current and a change in the oscillation frequency of the resonant circuit. Thus, the sensing coil must be kept in close proximity to the periphery of the coin tube. However, the sensing coil is normally installed in a circuit board. The installation of the sensing coil is restricted to the thickness and configuration of the circuit board, and unable to be smoothly attached to the smoothly curved periphery of the coin tube to shorten its distance relative to the metal coin in the coin tube, and thereby affecting the sensing accuracy. If the excitation frequency of the sensing coil is increased for effectively sensing metal coins in the coin tube, the follow-up signal processing will be complicated, increasing the cost.
Therefore, it is desirable to provide a coin acceptor, which is inexpensive to manufacture and can greatly improve the coin detection reliability and accuracy.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is therefore an object of the present invention to provide an in-coin passage coin sensing system, which has the advantages of ease of installation, low cost and high detection accuracy.
To achieve these and other objects of the present invention, an in-coin passage coin sensing system of the present invention comprises a main body, one or multiple coin tubes, and a sensing device. The main body comprises a body shell, and a coin dispenser mounted in the body shell. The coin tubes are mounted in the main body and disposed at the bottom side of the coin dispenser. The sensing device comprises a circuit module having a resonant circuit, sensing coils electrically connected to the resonant circuit, and an insulation film sealing the sensing coils and bonded to the periphery of the coin tubes to hold each sensing coil in the periphery of one respective coin tube in such a manner that when one or multiple metal coins are dispensed by the coin dispenser into one coin tube, an alternating magnetic field generated by one respective sensing coil induces eddy currents in the metal coins in the respective coin tube, enabling the circuit module to calculate the quantity of the metal coins in the respective coin tube by measuring the energy loss and change in resonance frequency in the resonant circuit subject to an equivalent parallel resonance impedance between the metal coins in the respective coin tube and the respective sensing coil. Because the insulation film has the characteristic of thin thickness, high toughness, low cost, excellent insulation effect and interference prevention, and facilitates smooth bonding of the sensing coils to the periphery of the coin tubes to keep the respective sensing coils in proximity to the metal coins in the respective coin tubes, enhancing metal coin sensing accuracy. Thus, the in-coin passage coin sensing system of the invention has the advantages of low cost and high detection accuracy.
Further, the sensing coils can be sealed with one common insulation film. Alternatively, each sensing coil can be sealed with one respective insulation film. Further, the insulation film is bonded to the smoothly curved periphery of each coin tube to hold the sensing coils in such a manner that each sensing coil extends along the length direction of the respective coin tube over a distance corresponding to the stacked thickness of the maximum quantity of metal coins storable in the respective coin tube.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of an in-coin passage coin sensing system in accordance with the present invention.
FIG. 2 is an exploded view of the in-coin passage coin sensing system in accordance with the present invention.
FIG. 3 is a schematic perspective view of a part of the present invention, illustrating the sensing coils sealed with an insulation film and bonded to the periphery of the coin tubes.
FIG. 4 is a front view of FIG. 3.
FIG. 5 is a schematic drawing illustrating the structure of the sensing device of the in-coin passage coin sensing system in accordance with the present invention.
FIG. 6 is a circuit diagram of the sensing device of the in-coin passage coin sensing system in accordance with the present invention.
FIG. 7 is a waveform graph illustrating the relationship between the resonant impedance response and the quantity of metal coins in accordance with the present invention.
FIG. 8 is a waveform graph illustrating the relationship between the inductance frequency response and the quantity of metal coins in accordance with the present invention.
FIG. 9 is a schematic perspective view of a part of an alternate form of the present invention, illustrating the sensing coils individually sealed with a respective insulation film before bonding.
FIG. 10 corresponds to FIG. 9, illustrating the sensing coils bonded with respective insulation films to the periphery of the respective coin tubes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1-6, an in-coin passage coin sensing system in accordance with the present invention is shown. As illustrated, the coin acceptor comprises a main body 1, a plurality of coin tubes 2 and a sensing device 3.
The main body 1 comprises a body shell 11, a coin dispenser 12 located in a top side of the body shell 11, an accommodation chamber 10 defined in the body shell 11 at a bottom side relative to the coin dispenser 12 and adapted for accommodating the coin tubes 2, and a coin hopper 13 located in the body shell 11 in a bottom side of the accommodation chamber 10. The coin dispenser 12 comprises a recognition module 121 adapted for recognizing the authenticity and values of different metal coins 4, a coin inlet 120 located in a top side of the recognition module 121 for guiding each inserted metal coin 4 into the recognition module 121, and a coin sorter module 122 adapted for sorting each recognized metal coin 4 and guiding it into one corresponding coin tube 2.
The coin tubes 2 are mounted in the accommodation chamber 10 inside the body shell 11 and located at a top side of the coin hopper 13 so that the coin hopper 13 can push metal coins 4 out of the coin tubes 2 to perform an exchange or change function. The coin tubes 2 are round tubes of different diameters, each defining therein a cylindrical coin passage 20 for receiving metal coins 4 of a mating diameter.
The sensing device 3 is mounted in the body shell 11 of the main body 1, comprising a circuit module 31, and a plurality of sensing coils 32 electrically connected to the circuit module 31 by electrical wires or conductors (not shown). Further, the sensing coils 32 are sealed or encapsulated with an insulation film 321, for example, Mylar polyester film or flexible polymer film. By means of the insulation film 321, the sensing coils 32 are respectively adhered to the cylindrical outer surfaces of the coin tubes 2 along the length direction. The size of the sensing coils 32 in the length direction of the coin tubes 2 is adjustably determined subject to the total height of maximum numbers of metal coins 4 stackable in the respective coin tubes 2.
In the aforesaid preferred embodiment, the circuit module 31 is mounted at the bottom side of the coin dispenser 12. However, in actual application, the circuit module 31 can be selectively mounted in the coin dispenser 12 or any other suitable location in the body shell 11. The circuit module 31 comprises at least one circuit board 310, and a resonant circuit (LC-tank) 311 and multiple electronic components 312 mounted in the at least one circuit board 310. The resonant circuit 311 comprises an oscillator, a resistor [Rp(d)], a capacitor (C) and an inductor [L(d)]. The electronic components 312 of the circuit module 31 include passive components, such as resistor, capacitor, inductor, diode and etc., or active components, such as microprocessor, transistor, IC chip, and etc. The circuit module 31 works with the sensing coils 32 to detect metal coins 4 and to process detected signals. As the application and signal processing circuit design of the circuit module 31 can be variously embodied using the known techniques, no further detailed description in this regard will be necessary.
Further, the in-coin passage coin sensing system of the present invention can be used in an automatic vending machine, game machine or any of a variety of other consumer service systems capable of selling commodities or providing services to consumers. When a user inserted a metal coin 4 through the coin inlet 120 into the coin dispenser 12, the recognition module 121 is activated to recognize the authenticity and value of the inserted metal coin 4. If the metal coin 4 is a true coin, it will be sorted by the coin sorter module 122 subject to its value and then guided into the corresponding coin tube 2 for storage. On the contrary, if the metal coin 4 is a counterfeit, it will be sorted by the coin sorter module 122 into a coin-return passage (not shown) in the main body 1 toward a coin-return outlet (not shown) in the face panel of the main body 1.
When the coin dispenser 12 dispenses a metal coin 4 into one coin tube 2, the oscillator of the resonant circuit 311 of the circuit module 31 of the sensing device 3 generates an excitation signal at a predetermined oscillation frequency to induce the respective sensing coil 32, causing the respective sensing coil 32 to generate an alternating magnetic field for sensing metal coins (conductance of metal) 4. When one metal coin 4 is located in close proximity to the sensing coil 32, eddy currents will be induced in the metal coin 4, and thus an energy loss in the resonant circuit 311 can be measured. Subject to the equivalent parallel resonance impedance (Rs) between the metal coins 4 in each coin tube 2 and the respective sensing coil 32, the inductance [L(d)] of the energy loss and change in oscillation frequency in the resonant circuit 311 can be measured. Thus, circuit module 31 can calculate the quantity of metal coins 4 in each coin tube 2 by measuring the energy loss and change in oscillation frequency in the resonant circuit 311.
By means of the insulation film 321, the sensing coils 32 are smoothly clamped, bonded or adhered to the periphery of the respective coin tubes 2 for sensing metal coins 4 in the respective coin tubes 2 within a very short distance. The closer the metal coin is, the higher the sensing accuracy will be. Thus, the energy loss and change in the oscillation frequency in the resonant circuit 311 can be accurately measured by the circuit module 31, assuring a high level of reliability. Further, the insulation film 321 has the characteristic of thin thickness, high toughness, low cost, excellent insulation effect and interference prevention, and facilitates smooth bonding of the sensing coils 32 to the periphery of the coin tubes 2. Thus, the in-coin passage coin sensing system of the invention has the advantages of low cost and high detection accuracy.
Referring to FIGS. 7 and 8, waveform graphs respectively illustrating the relationship between the resonant impedance response and the quantity of metal coins and the relationship between the inductance response and the quantity of metal coins are shown. As illustrated, the circuit module 31 measures the energy loss and change in the oscillation frequency in the resonant circuit 311 subject to equivalent parallel resonance impedance between the quantity (for example, 1, 5, 9, 13, ... 65 and etc.) of metal coins 4 and the sensing coil 32 to make a reference data in resonant impedance response (ohm) and inductance frequency response (kHz). When one or multiple metal coins 4 enters one coin tube 2, the distance between the respective sensing coil 32 and the metal coins 4, the geometric shape (size and thickness) and magnetic permeability of the metal coins 4 will cause a change in the eddy current. Thus, the circuit module 31 can measure the energy loss and change in the oscillation frequency in the resonant circuit 311 and compare the measured data with predetermined reference data, thereby calculating the relative quantity of the metal coins 4 in the respective coin tube 2.
Referring to FIGS. 9 and 10 and FIGS. 2 and 4 again, in the embodiment shown in FIGS. 2-4, the sensing coils 32 of the sensing device 3 are sealed with one single piece of insulation film 321. Alternatively, as shown in FIGS. 9 and 10, each sensing coil 32 can be individually sealed with one respective insulation film 321 and then bonded with the respective insulation film 321 to the smoothly curved periphery of the respective coin tube 2. Because the insulation film 321 is thin, flexible and tough, it can be smoothly bonded to the periphery of the respective coin tube 2, keeping the respective sensing coil 32 in proximity to the metal coins 4 in the respective coin tube 2, enhancing metal coin sensing accuracy.
It is to be understood that the above-described embodiment of the invention is merely a possible example of implementations, merely set forth for a clear understanding of the principles of the invention, many modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.

Claims

An in-coin passage coin sensing system, comprising a main body, at least one coin tube and a sensing device, wherein said main body comprises a body shell and a coin dispenser mounted in said body shell; said at least one coin tube is mounted in said body shell of said main body and disposed at a bottom side of said coin dispenser and adapted for receiving metal coins being dispensed by said coin dispenser; said sensing device comprises a circuit module comprising a resonant circuit, at least one sensing coil electrically connected to said resonant circuit of said circuit module, and at least one insulation film sealing said at least one sensing coil and fastened with said at least one sensing coil to the periphery of said at least one coin tube to hold each said sensing coil in the periphery of one respective said coin tube in such a manner that when one or multiple metal coins are dispensed by said coin dispenser into one said coin tube, an alternating magnetic field generated by one respective said sensing coil induces eddy currents in the metal coins in the respective said coin tube, enabling said circuit module to calculate the quantity of the metal coins in the respective coin tube by measuring the energy loss and change in resonance frequency in said resonant circuit subject to an equivalent parallel resonance impedance between the metal coins in the respective said coin tube and the respective said sensing coil.
The in-coin passage coin sensing system as claimed in claim 1, wherein said resonant circuit of said circuit module is an LC tank circuit.
The in-coin passage coin sensing system as claimed in claim 1, wherein said at least one insulation film is sealed to said at least one sensing coil and fastened to the periphery of said at least one coin tube by bonding or clamping techniques, or with an adhesive.
The in-coin passage coin sensing system as claimed in claim 1, wherein said at least one coin tube comprises a plurality of coin tubes having different diameters for receiving different metal coins having different values; said sensing device comprises a plurality of said sensing coils; said at least one insulation film is an one-piece member sealing said sensing coils and bonded to the periphery of each of said coin tubes to hold each said sensing coil closely to the periphery of one respective said coin tube.
The in-coin passage coin sensing system as claimed in claim 1, wherein said at least one coin tube comprises a plurality of coin tubes having different diameters for receiving different metal coins having different values; said sensing device comprises a plurality of said sensing coils, and a plurality of said insulation films respectively sealed to said sensing coils and bonded with the respective said sensing coils to the periphery of the respective said coin tubes to hold each said sensing coil closely to the periphery of one respective said coin tube.
The in-coin passage coin sensing system as claimed in claim 1, wherein said at least one insulation film of said sensing device is a Mylar polyester film.
The in-coin passage coin sensing system as claimed in claim 1, wherein said at least one insulation film of said sensing device is a plastic film.
The in-coin passage coin sensing system as claimed in claim 1, wherein each said sensing coil of said sensing device extends along the length direction of the respective said coin tube over a distance corresponding to the stacked thickness of the maximum quantity of metal coins storable in the respective said coin tube.