JP2934563B2 - Coin sorting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coin sorting device applied to a toll collection device, a vending machine, and the like.

[0002]

2. Description of the Related Art A coin sorting apparatus generally has a detector called a bridge, and is operated by an impedance change method.
The coins to be inserted are identified. That is, the bridge is composed of a resistor and a coil,
A voltage having a specific frequency and amplitude is applied. Thus, when a coin approaches the coil, the bridge outputs a voltage whose amplitude and phase change uniquely according to the coin.

FIG. 3 is a diagram showing a coin sorting apparatus to which such an impedance change method is applied, and is composed of a plurality of voltage comparators and a plurality of phase comparators. The quantity of each comparator is required only for the type of coin to be sorted. The sorting principle of this device will be described with reference to FIG. When a coin approaches the coil 20 for coin detection, the impedance of the coil 20 changes and the output voltage waveform from the bridge 21 changes. The output voltage is applied to the amplifier 22,
The signal is amplified at 23 and output to a plurality of voltage comparators 24, 25, 26 and a plurality of phase comparators 27, 28, 29.

[0004] Certain coin data is set in the voltage comparator 24, and its range is from _VOA to _VUA in FIG. 4 (A). If the input waveform is within the range of the set value. For example, the output signal from the voltage comparator 24 is as shown in FIG. Further, the specific coin data is also stored in the phase comparator 27 as φ
It is set as _OA and φ _UA. Therefore, if the input phase is within this range, the output signal from the phase generator 27 is as shown in (D). The signal of (C) and the signal of (D) are input to the AND circuit 30, and if both have the level "1", the signal as shown in (E) is output. This signal is input to the determination circuit 33 to identify the coin.

[0005]

In the above-mentioned conventional coin sorting apparatus, it was difficult to sort coins having similar materials in principle. That is, as shown in FIG. 5, the amplitude of the voltage waveform output from the bridge is mainly determined by the size of the coin, and the phase is mainly determined by the material of the coin. Therefore, the 50-yen coin and the 100-yen coin having similar materials are distributed on substantially the same phase difference as in the range 40 and the range 41, respectively, and only their amplitudes are different as shown by the solid lines 42 and 43 in the figure, respectively. . Therefore, when the inserted coin approaches the detection coil 20, the combined vector of the amplitude and the phase draws a locus as indicated by a dotted line 44 in the figure. For this reason, a signal is output to the determination circuit within the setting range of 50 yen and 100 yen, and it is not possible to discriminate between a 50-yen coin and a 100-yen coin.

Further, in the conventional coin sorting apparatus, a pair of voltage comparison circuits and phase comparison circuits are required for each coin to be sorted, and the circuit configuration is large and complicated. Further, when a new coin is issued, there is a problem that a circuit for the new coin must be added and adjusted.

[0007] Therefore, an object of the present invention is to prevent coins from being erroneously selected even if they enter the range of other coin data in the process of the coin approaching the detection coil. An object of the present invention is to provide a coin sorting device capable of realizing cost reduction and labor saving of adjustment.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems and to achieve the object, the present invention provides a bridge for outputting a voltage whose amplitude and phase change when a coin is inserted, and an output voltage of the bridge. An analog-to-digital converter, a reference signal generator for generating a reference signal having a specific frequency and amplitude applied to the bridge, a reference signal generated from the reference signal generator, and a voltage output from the bridge. Two interrupt generators for detecting the respective zero levels of the signal, and holding the maximum value of the digital amount corresponding to the output voltage digitally converted by the AD converter, and generating an interrupt from the two interrupt generators A central processing unit is provided for detecting a phase difference in time and determining that the inserted coin is a genuine coin based on the maximum value and the phase difference.

[0009]

The following effects are obtained as a result of taking the above measures. That is, the output voltage waveform from the bridge is input to the interrupt generator and the AD converter. The interrupt generator causes an interrupt to a central processing unit (hereinafter abbreviated as CPU) when the output voltage waveform of the bridge crosses the zero level, and the AD converter converts the amplitude value of the output voltage waveform into a digital amount. And transmits it to the CPU. Another interrupt generator causes the CPU to generate an interrupt when the reference signal waveform applied to the bridge crosses the zero level. Therefore, the CPU obtains the phase from the time difference between the two interrupts,
From the digital amount from the D converter, the amplitude value of the output voltage waveform of the bridge is obtained. In the CPU, AD
The magnitude of the digital quantity corresponding to the amplitude quantity received from the converter is compared, the maximum value is stored, and the phase difference is also stored. Then, when the coin moves away from the detection coil, a genuine coin is determined based on the maximum value of the amplitude value and the phase difference. Therefore, coin sorting can be performed based on the maximum amplitude value and the phase difference of the output waveform of the bridge,
In the process of the coin approaching the detection coil, erroneous sorting is prevented even if the coin enters the range of other coin data. In addition, since the coin data is set by software of the CPU, the coin data can be easily changed.

[0010]

FIG. 1 is a block diagram showing a configuration of a coin sorting apparatus according to one embodiment of the present invention.
FIG. 4 is a diagram showing waveforms of respective parts. In FIG. 1, reference numeral 1 denotes a reference signal generator for generating a signal having a specific frequency and amplitude. A bridge 6 is formed by the detection coil 2, the temperature compensation coil 3, and the resistors 4 and 5. Note that S ₁ , S ₂ ,
S ₃ and S ₄ indicate connection points. The reference signal generator 1 is connected to the connection points S ₁ and S ₃ of the bridge 6, and the connection point S ₃ is grounded.

The connection points S ₂ and S ₄ of the bridge 6 are connected to an amplifier 7 for amplifying the output voltage waveform of the bridge 6, and the output terminal of the amplifier 7 is connected to an interrupt generator 8. On the other hand, the connection point S ₁ of the bridge 6 is connected to the interrupt generator 9. The output terminal of the amplifier 7 is further connected to A
It is connected to the D converter 10. Interrupt generators 8, 9
The output terminal of the AD converter 10 is connected to the CPU 11.

The coin sorting apparatus thus constructed operates as follows. That is, from the reference signal generator 1 to FIG.
A signal having a specific frequency and amplitude of a waveform as shown in (a) is output and applied to the bridge 6. At this time, when the inserted coin approaches the detection coil 2, the output voltage waveform of the bridge 6 changes in amplitude and phase as shown in FIG. In particular, the amplitude shows the maximum value 13 when the coin approaches the most. In the interrupt generator 8, when the output voltage waveform of the bridge 6 crosses the zero level, the state changes as shown in FIG. Since the CPU 11 detects an interrupt at the rising edge of the waveform in FIG. 2C, the timing is as shown in FIG.

In the interrupt generator 9, when the reference signal crosses the zero level, the state changes and is output to the CPU 11. The output voltage waveform at this time is as shown in FIG. Similarly, the CPU 11 detects an interrupt at the rising edge of the waveform, and the timing is as shown in FIG. Further, the CPU 11
In this case, the above two interruption intervals ΔT15 to ΔT17 are sequentially monitored, and this is processed as data for coin sorting as a phase difference between the reference signal and the output voltage waveform from the bridge 6.

On the other hand, the amplitude value is obtained as follows. That is, the amplitude values 12 to 14 of the output voltage waveform from the bridge 6 correspond to the voltage values when the phase is delayed by π / 4 after the interrupt generator 8 generates the interrupt signal to the CPU 11. The output voltage waveform of the bridge 6 is compared with the reference signal and changes only in the amplitude value and the phase, and the fundamental frequency does not change. Therefore, if the frequency of the reference signal is recognized in advance, the phase amount of π / 4 is replaced by the time amount by the CPU 11 and time monitoring is performed. At that time, the conversion start signal is output to the AD converter 10. Thus, the amplitude value during one cycle can be obtained. The CPU 11 sequentially compares the magnitudes of the digital quantities corresponding to the magnitudes of the amplitudes received from the AD converter 10, and stores the maximum value and the phase difference. Then, when the coin moves away from the detection coil 2, a genuine coin is determined based on the maximum value of the amplitude value and the phase difference.

As described above, in the coin sorting apparatus of the present embodiment, in the process of the coin approaching the detection coil, even if the coin enters the set range of other coin data, the judgment is made only by the maximum value of the amplitude. Therefore, no erroneous judgment is made. Further, each coin data is set as software inside the CPU 11, and the change is easy. It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.

[0016]

According to the present invention, coins are sorted on the basis of the maximum amplitude value and the phase difference of the output waveform of the bridge. Therefore, during the process of the coin approaching the detection coil, the range of other coin data is limited. Even if it invades, it will not be mis-sorted. Also, since these coin data is set by the software of the CPU,
Not only is it easy to change the coin data, but new coins can be handled only by changing the software without changing the hardware. Therefore, the circuit configuration can be simplified as compared with the conventional one which requires a voltage comparator and a phase comparator for the type of coins, and coin sorting which can realize low cost and labor saving in adjustment. Equipment can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a coin sorting device according to a first embodiment of the present invention.

FIG. 2 is a waveform diagram of each part for explaining the operation of the coin sorting apparatus according to the embodiment.

FIG. 3 is a configuration diagram of a conventional coin sorting device.

FIG. 4 is a waveform diagram for explaining the operation of the conventional coin sorting apparatus.

FIG. 5 is a view for explaining a problem when the conventional coin sorting apparatus is used.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reference signal generator 2 ... Detection coil 3 ... Temperature compensation coil 4,5 ... Resistor 6 ... Bridge 7 ... Amplifier 8,9 ... Interrupt generator 10 ... AD converter 11 ... CPU 12-14 ... Output from bridge Amplitude value of each cycle of the waveform to be generated 15 to 17... Phase difference of each cycle of the waveform output from the reference signal and the bridge

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int.Cl. ⁶ , DB name) G07F 3/04 G07D 3/14 G07D 5/00-5/10

Claims (1)

(57) [Claims] 1. A bridge for outputting a voltage whose amplitude and phase change when a coin is inserted, an AD converter for digitally converting the output voltage of the bridge, and a specific frequency and amplitude applied to the bridge. A reference signal generator for generating a reference signal, two interrupt generators for detecting respective zero levels of a reference signal generated from the reference signal generator and a voltage signal output from the bridge, and the AD converter Holds the maximum value of the digital amount corresponding to the output voltage converted into a digital value, detects the phase difference between the interrupt occurrence times from the two interrupt generators, and determines that the inserted coin is correct by the maximum value and the phase difference. A coin sorting device comprising: a central processing unit that determines that the coin is a coin.