CN1036470A

CN1036470A - Coin validation apparatus

Info

Publication number: CN1036470A
Application number: CN88108657A
Authority: CN
Inventors: 罗杰·威廉·沃特英尔; 保罗·克里斯托弗·奥斯邦德
Original assignee: Telent Technologies Services Ltd
Current assignee: Telent Technologies Services Ltd; Plessey Telecommunications Ltd
Priority date: 1987-11-24
Filing date: 1988-11-23
Publication date: 1989-10-18
Also published as: GB8727526D0; GB8827161D0; DK655688D0; ZA888742B; AU2583588A; GB2215505A; PT89058A; DK655688A; BR8806169A; EP0318229A2; JPH01244593A; EP0318229A3

Abstract

Coin validation apparatus comprises: Coin sideway is arranged to the coin of aiming at access to plant and makes itself and a hard hit hit surperficial the contact; Acoustic pickup can detect coin and clash into the acoustical vibration that sends behind the said surface; Electronics circuit can compare data from said coin with the stored data of representing one group of standard coinage and point out which coin value is consistent with the coin value that enters said device; Wherein, comprise a Coin validator, can when detecting the coin of access to plant, drive said circuit at electronics circuit device in front.This detecting device can be an acoustic pickup 4.

Description

Coin validation apparatus

The present invention relates to Coin validation apparatus, relate in particular to the device that can detect the coin value that drops into coin slot, therefore it can be used in vending machine, phone coin box, save machine or other need be checked in the suitable equipment of the coin value that is dropped into by possible client or user.

According to the present invention, Coin validation apparatus is provided, this device comprises a Coin sideway, with its be arranged to can aim at the coin that enters this device make coin can and a hard impact surface realization contact, also comprise an acoustic pickup, be located and detect the acoustical vibration that back, the said surface of coin bump is sent, also comprise an electronics circuit, it can be consistent with the coin value that enters said device with comparing and indicate which coin value from the data of said coin and the stored data of representing one group of standard coinage, wherein comprise a Coin validator, it is arranged to when detecting coin that enters this device, drives said circuit in this electronics circuit device part in front.

In an embodiment, this Coin validator can comprise a pressure transducer that is bonded to said impact surface.This pressure transducer can be piezoelectricity or pressure drag material body.On the other hand, the capacitance variations that this Coin validator also can cause according to coin, electromagnetic induction changes or the variation of beam Propagation.

In another embodiment, Coin validator may drive said circuit according to exporting from the electricity of acoustic pickup.

With reference to the accompanying drawings, by means of example some specific embodiment of the present invention is described, wherein

Fig. 1 represents a kind of form that coin should the reality device, is used to obtain the sound spectrum that coin sends;

Fig. 2 is the calcspar of an electronics circuit, is used to discern the coin value of input;

Fig. 3 is a similar calcspar of a narrow-band pass filter of this electronics circuit;

Fig. 4 and Fig. 5 are illustrated in some signals that obtain when detecting some specific coins in the circuit of Fig. 2;

Fig. 6 has described the result who a coin is carried out fast Fourier transformation;

Fig. 7 represents the side view and the planimetric map of the another kind of form of Coin validation apparatus;

Fig. 8 represents the voltage signal that different coin values obtained from the piezoelectric sensor of device shown in Figure 7;

Fig. 9 represents the P-to-P voltage that obtains from different coin values; And

Figure 10 has represented to utilize the another kind of form of the Coin validation apparatus of induction method for sensing.

When coin strikes a hard object, this coin will be with one group of specific mode vibration, the pattern of vibration is by the metal of forming this coin and size (if the thickness coin is circular its diameter and other virtually any size characteristic in addition, for example whether having facet, hole or different component district) decision thereof.The sound that coin sends will comprise the information of relevant these resonance modes, and its relative amplitude will change with the time behind the coin bump.The device that Fig. 1 represents can be used to obtain the sound spectrum that coin sends.Allow coin 1 to drop on the slideway 2 so that bump elastic plate 3 and sounding.Detect the sound that is sent at a pressure acoustic pickup 4.

The optimum position of this acoustic pickup is the front near coin, rather than the edge of coin, because the signal in this position is maximum.But, can both provide a utilizable signal near any position easily of coin.The detected signal of acoustic pickup is added to as shown in Figure 2 circuit.

Fig. 2 is a calcspar of discerning the electronics circuit of the coin value that drops into.As shown in the figure, acoustic pickup 4 is linked on the amplifier 6, linked bandpass filter 7 by amplifier 6.The output of wave filter 7 is added to a RMS detecting device 8(, and it is a phase sensitive detector), and then link this schmitt trigger equipment 9.

In the circuit of Fig. 2, after amplifier stage, wave filter 7 is " trap " wave filters, with its frequency configuration on the frequency of the fundamental resonant pattern of coin to be identified.A kind of form of the composition of such wave filter as shown in Figure 3, their the effect be a narrow bandpass filter.Fig. 3 represents an audio frequency (AF) oscillator 11, and it is linked a reference unit 12, unit 12 give phase sensitive detector 13 provide a frequency and phase place all with from the identical square-wave signal of the signal of audio frequency oscillator 11.Signal input on online 14 also is added to detecting device 13, obtains an output like this on online 16

Among Fig. 3, reference unit 12 is Brookdeal type Unit 9422, and phase sensitive detector 13 is Brookdeal type Unit 9412.Set the frequency of this final wave filter by audio frequency oscillator, and the output of phase sensitive detector 13 is inversely proportional to the frequency set by audio frequency oscillator 11 and the difference on the frequency between the signal incoming frequency.The output of signal on online 16 is an AC signal, and its frequency equals the input signal on the line 14 and the difference on the frequency of the signal set by audio frequency oscillator 11.Importantly the frequency span of this wave filter wants enough big, only in this way just can detect the resonance of all coins with a special denomination, and this frequency span is also enough narrow simultaneously, only in this way just can avoid the generation of the falseness detection of different denomination of coin.For this reason, it is enough for 5% frequency span.

After filtering stage, use RMS detecting device 8, detecting device 8 will provide a root mean square signal (see figure 2) that is proportional to by the AC signal of this wave filter.After this part of circuit is this schmitt trigger 9 and monostable 17.This this schmitt trigger 9 is output as 0 volt (logical zero) when the output of RMS circuit is lower than a predetermined voltage, and the output of trigger 9 equals the output (logical one) of positive voltage source when the output of RMS circuit is higher than this predetermined voltage.Monostable 17 triggers when logical one and remains on schedule time of logical one, can be to have this information of special denomination to move according to this coin so that make the circuit of following processing coin and plant equipment.What Fig. 4 and Fig. 5 represented is some signals that produce when using coin in this device.

Fig. 4 is illustrated in the output level of such wave filter of describing when using specific coin in the device of Fig. 1 in Fig. 3.Z-axis is illustrated in peak-peak voltage (unit the is volt) output amplitude of the signal that the output terminal of RMS detecting device 8 measures.Scale is from 0 to 4.0 volt.Horizontal line A has provided and the corresponding level of 9.987 khz frequencies.Transverse axis among the figure is represented is that to be worth be 10,5, the 2 different amplitudes that produce with 1 penny coin.As seen from the figure, have only 10 pennies of coins to produce and surpass the amplitude that level is differentiated in the appointment of being represented by line A.

Fig. 5 is one similarly to scheme with Fig. 4, and wherein the topped scope of Z-axis is from 0 to 1.0 volt, and to mark frequency with line B be 8.460 kilo hertzs discriminating level.Check 4 kinds of identical coins, as can be seen, at this moment have only 2 pennies of coins to produce amplitude and surpass the discriminating level of representing by line B.

This shows, under these two situations, can set a signal level, this level will only help identifying a kind of specific coin from actual all coins.

Exist a kind of meeting to make equipment as described herein provide the situation of a false triggers reaction.This thing happens is that a kind of size of coin is different with the coin of expectation with metal types but by chance have a similar resonant frequency with the coin of expectation.A kind of like this coin can be used to measure the diameter of the coin of sending this system to by being provided with one, also have the equipment of its thickness to sort out if possible.This sorting of coin just can in so many words be provided with a simple logical circuit then.The proper method that carries out diameter measurement comprises induction technology and optical technology.The another kind of method of measuring coin diameter is the following structure of utilizing a specific resonance mode that will describe.

Allow the circuit parallel connection shown in Figure 2 of arbitrary number of selected different filter frequencies, just can constitute the system of a series of different coins of energy sorting with each coin can be topped to be identified.Each circuit all links to each other with a measurement device of diameter, so that the sorting and the selection of mistake provided further protection.

Can make the improvement that a series of improvement divide selection operation for above-mentioned single system.

In first embodiment, should be realized that, impinge upon more than one an of vibration mode that coin produced on the sheet metal, and should be realized that, although basic flexure mode is occupied an leading position, like this vibration of some other patterns is all influential thereby sound that promptly coin is sent is all influential to this mode configuration such as high-order flexure mode, radial mode and thickness mode.Have, to each coin, the instantaneous shape of every kind of pattern is all inequality again, and this depends on the coupling between institute's emergence pattern and the program of each pattern decay.These factors depend on the material that constitutes coin, physical size and (considering that not every coin all is this fact of simple disc) shape thereof of coin again.Therefore recognize, can realize the identification of coin by frequency/time structure of analyzing the sound that coin sends.Can realize this point by one of following mode:

A) with the digitized sound that sent and to its record, final signal is carried out fast Fourier transformation (FFT).The FFT function is included as the information of all frequencies of finishing the coin recognizing method required by task, and this can finish with the digital correlation of a series of inventory functions of different coins by the FFT function that utilizes this coin.

By using a kind of Wavetek58 20A fft analysis device, using a kind of Bruel and Kjaer4135 acoustic pickup to detect the availability that voice signal confirms this design.Fig. 6 has provided the example to the sound spectrum of independent coin record.

Fig. 6 has provided two curves, and the vertical scale of the curve of top is represented the voltage that records from sensitive acoustic pickup, voltage value from-4 to+4.Transverse axis express time (second), from 0 to 5.8 millisecond.Acoustic energy in the Z-axis whetstone coltfoal hertz frequency width of lower curve, unit is a decibel, scale is from-90 to 10.Transverse axis is represented frequency (is that unit measures with the hertz), and scale is from 0 to 50,000.

Can clearly see a plurality of peak values that produce by different resonance modes.

Peak in the sound spectrum is the feature of coin denominations, and table 1 has been listed some frequency ranges that are up to 50 kilo hertzs, and wherein the large and small resonance peak of these sound spectrums obtains a cover Britain coin.

Table 1

5 pennies 10 pennies 20 pennies 50 pennies 1 pound of denomination

Frequency range

9.4-9.8 B A

9.9-10.5 A A A

12.8-13.2 A

16.8-17.2 A A

17.9-18.8 A A

18.8-19.5 A

21.6-21.8 A

21.9-22.0 A

22.1-22.4 A

23.9-24.1 A

29.9-30.3 A

31.1-31.3 B

31.6-33.0 A

35.4-35.9 B

36.0-36.5 B

37.5-38.4 B A

39.3-39.4 A

Table 1(is continuous)

5 pennies 10 pennies 20 pennies 50 pennies 1 pound of denomination

Frequency range

40.8-42.1 A A

46.3-46.6 B

47.1-47.5 A

48.9-49.0 A

49.1-49.2 A

" A " represents a resonance peak clearly

" B " represents a submaximum, perhaps identical but the vibration between the coin not same date of denomination.

The scrutiny sound spectrum just discloses, and exists extremely significantly difference between most of coins, therefore only just should be able to get good discriminating according to sound characteristic between these coin denominations of great majority.

B) the enable voice signal passes through the instantaneous vibration of the signal of each wave filter by a bank of filters (each wave filter is corresponding to a frequency in the table 1) and record.Then, with these instantaneous vibrations be stored in the data in the database and compare to obtain the identification of coin.Realize the mode of this bank of filters or use the low-frequency sound wave wave filter, or remove to modulate a radio-frequency carrier with the sound that coin produces, (can hand over Jia to be stained with the brain ǎ bad bangs of the private school vermachen scheme frequently of betraing of dying young frequently of the bad bangs of Shan wink ㄆ bone speech enlightening Zheng  alcohol  bustard with surface acoustic wave nurse strand sips and swings the young Gan shelves bangs of  U Buddhist nunnery product green pepper  and support the glutinous rehmannia cave and waste time that to coil up system in order to do wink ㄆ demons and monsters  chessboard sound of a bird chirping most extremely by using some discrete radio-frequency filters again

In a second embodiment, recognized in a system of describing such as Fig. 1, provide certain can detect the existence of coin and be used for connecting sound know the device of recognizing circuit will be useful.Design a series of possible methods for this reason.

A) elastic plate 3 that is clashed into by coin provides one to touch quick branch, and this touches quick part and can provide an electric signal and trigger sound circuit.Such one is touched quick part and can be provided with the form of a mechanical switch or an electric transducer.A kind of suitable electric transducer can be a PZT piezoelectric ceramics, lithium niobate piezoelectric monocrystal or the PVDF piezoelectric plastics material that is bonded on this elastic plate 3, and the device that is suitable for doing like this has been shown among Fig. 7.In this case, piezoelectric 18 is bonded to the back side of plate 3, therefore when coin 1 crash panel 3 it with bending, by means of just having produced an electricity output on the piezoelectric effect online 19.The advantage of this method is the quality that output is proportional to coin 1, this output can be used for the electronics circuit of this system with out of Memory so that provide other method of identification coin.Below this demonstration to be described.To be welded to by the PZT-5 disk that piezoelectric 18 is formed on the plate 3, plate 3 is made of phosphorus/bronze flake, is of a size of 0.8X12X51 centimetre.。Allow coin 1 slide crash panel 3 from a known fixed range along the slideway that is made of slope 21, the output of the PZT disk on the line 19 is added on the oscillograph by an amplifier.Fig. 8 expresses the shape of the output that obtains from several different coins, and from the top curve, these coin values are respectively 50,10,5,2 and 1 pennies.In these curves, the scale of Z-axis is 5 volts of each grids, and the tolerance of transverse axis is 0.5 millisecond of each grid.

Fig. 9 represents is dependence between the P-to-P voltage that recorded and the used different coins, from 4 to 24 volts of the voltages of the Z-axis shown in the figure.As seen from the figure, the characteristic of coin can be characterized by these magnitudes of voltage, and these magnitudes of voltage are handled classification and provided Useful Information.The formation of these voltages output is very complicated, and remain by the type decided of given coin.By utilizing the correlativity of these waveform shapes and the known waveform of the different coins of database, also these waveform shapes can be used for the sorting of coin.As the another kind of scheme of utilizing with piezoelectric d 31 coefficients of the bending coupling of elastic plate 3, one that place elastic plate 3 fronts and may provide the definite indication that has coin with the piezoelectric material body of its d33 mode work.Can be used for constituting other electric transducer that touches quick part and comprise the pressure drag polymkeric substance, as the charcoal rubber of conduction, it can provide a resistance variations when being subjected to the coin bump.In addition, if require the bump of coin to provide a capacitance variations, then can use a plastic/metal interlayer that constitutes parallel plate capacitor.

B) can also provide the signal that an indication coin exists by the usability induction method on the other hand.The form that makes device in this way can get two coaxial coils, one of them coil passes to alternating current.These two coils can be by arranging that as shown in figure 10 first coil 22 wherein surrounds second coil 23.Existence by coin causes that the variation of coil mutual inductance has changed the signal that produces owing to the electric current that flows in first coil in second coil 23, and this just can be used to indicate the existence of coin.

C) can use a simple beam sensor to indicate the existence of coin.If provide light beam to the detecting device with a light source, then the cut-out of light beam has just provided the indication that coin exists, and available its triggers electronics sensitive circuit.

Below only by means of case description embodiment of the present invention, can make a series of improvement not leaving under the situation of the scope of the invention as defined by the appended claims.For example, an available direct pressure gradient acoustic pickup replaces the pressure acoustic pickup shown in Fig. 1.The pressure acoustic pickup can suffer the interference of external noise source, the work that these noise sources may EVAC (Evacuation Network Computer Model).Although can have good sound to isolate the influence that alleviates these interference greatly by guaranteeing acoustic pickup and external environment condition, in some cases, for example in extremely noisy environment, to work, working pressure gradient acoustic pickup is useful.A kind of like this acoustic pickup but is very sensitive to the pressure gradient that is caused by near the sound source close this acoustic pickup still to not producing response such as the environment sound pressure variations that is caused by remote noise source.Therefore, the sound that a kind of like this acoustic pickup takes place the vibration coin near it can produce well response, but very insensitive to neighbourhood noise.This acoustic pickup also has very strong directivity, if therefore correct location just can be provided for identifying the signal that the vibration coin produces from ground unrest.

Claims

1, a kind of Coin validation apparatus, it comprises a Coin sideway, be arranged to and aim at the coin that enters this device, make it realize contacting with a hard impact surface, an acoustic pickup, be located and detect coin and clash into the acoustical vibration that sends behind the said surface, an electronics circuit, it can compare and point out that with the stored data of representing one group of standard coinage which coin value is consistent with the coin value that enters said device with the data from said coin, wherein, comprise a Coin validator in this electronics circuit device part in front, it is arranged to when detecting coin that enters this device, drives said circuit.

2, a kind of device as claimed in claim 1, Coin validator wherein comprises a pressure transducer that is bonded to said impact surface.

3, a kind of device as claimed in claim 2, wherein said pressure transducer is a kind of piezoelectric material body.

4, a kind of device as claimed in claim 2, wherein said pressure transducer are a kind of pressure drag material bodies.

5, a kind of device as claimed in claim 1, the capacitance variations that wherein said Coin validator causes according to coin, the variation of electromagnetic induction variation or beam Propagation.

6, a kind of device as claimed in claim 1, wherein said Coin validator is exported to drive said electronics circuit according to the electricity from acoustic pickup.

7, Coin validation apparatus foregoing basically, that describe with reference to any one accompanying drawing.