JPS62131397A - Coin identifying method and apparatus - Google Patents

Abstract

Certain properties of a coin (1) are measured while the coin runs down a ramp (2) and passes between a pair of coils (6). Measurements in the form of attenuated signals (A1, A2, A3, Amax) are taken at several positions determined by coin edge sensing means (3, 4, 5) detecting the trailing edge of the coin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention comprises a body for guiding a coin through a passage in which certain characteristics of the coin are measured by means of an electromagnetic device, and at different positions of the coin in the passage. The present invention relates to a coin identification method in which many measurements are performed and an apparatus used therein.

[Prior Art] For example, a coin filter is disclosed in British Patent Application No. 1,551.2.
09 (a device in which the electromagnetic response is measured with respect to the speed with which a coin passes through a detector during a predetermined period of time), UK patent application no. The coin identification device has an induction coil wrapped around a ferrite core with two poles matched to the position of the coin, and the influence of the coin on the electromagnetic field is
(measured when adjacent to each polar plane)
, UK Patent Application No. 2,086,633! (Coin identification device with combination of MFA and photoelectric sensors to determine coins of different magnetic permeability), DE-O8
No. 2,716.740 (A device with a complex system of capacitive-inductive and photoelectric sensors to identify coins).

[Problems to be Solved by the Invention] These known methods are considered to have unreliable results. The aim of the invention is therefore to overcome the drawbacks of known coin filters.

[Means for Solving the Problems] The main features of the present invention are that a coin identification method in which a certain characteristic of a coin is measured by an Mm device and multiple measurements are taken at different positions of the coin in a passageway; A coin identification method comprising a coin guide through a passage, characterized in that two or more electromagnetic measurements are taken at positions determined by sensing means.

The invention provides a coin filter that is independent of the time the coin passes through the detector. The present invention is simple because it uses only one set of electromagnetic coils to perform several consecutive magnetic measurements on each coin. The position at which the coin is measured is determined by the coin itself.

[The general principle of the embodiment is shown in FIG. All coins 1 that have entered the device fall down the ramp 2 and are measured dynamically in a short time and with minimal power.

The coin passes through the optical paths 3 and 4 before passing through the center of the pair of coils 6.
．． Interrupt 5.

The reduction in coupling between the coils is measured several times on the coin at different positions controlled by the optical path.

The principle of measurement is shown in FIGS. 2 to 4.

The coupling between the coils 6 will first be explained. A sinusoidal signal E is produced by one coil GE. Two coils (GE,
CR) When there is no coin in between, the signal is received without attenuation. The field of view of the received signal R is determined by the coupling coefficient of the two coils. Coil with two coins (GE, C
R), the received signal is attenuated.

The difference in amplitude (attenuation Ai) of the received signal is the result of measurements being made at different positions on the coin (Al, A2, A3, -A
n and AmaX)T”.

The optical paths 3, 4.5 are arranged at different heights above the ramp 2 and at different distances from the coil center. The optical paths are arranged such that no optical path simultaneously hits the trailing edge of a passing coin. For different coin diameters, there is a light path located close to the top of the coin, which is at least 80% of the coin diameter. A high diameter selection is achieved by performing the coupling measurement at the moment when the traveling coin opens the optical path, since small differences in diameter cause very large differences 7 in the part of the coin that is present between the sensing parts 8 of the coil at that time. You can get sex. This is shown in FIG.

By making further measurements in sequence with the same pair of coils, not only the maximum attenuation but also the rate of change in attenuation is determined. This displays the type of coin. The largest and usually most valuable coins interrupt most of the optical path, thereby allowing suitable measurements to be made. Preferably, the first measurement shows the lowest attenuation. The optical path should cover at least 1% (preferably 1%) of the coin area when the first measurement is taken.
20%) within the sensing portion of the coil.

A block diagram of the coin recognition circuit is shown in FIG. 5 (in the following description, the number of optical paths is set to 3).

The coin identification device comprises a microcomputer 10 having the following control lines.

LCI, LC2, LC3: Optical path selection line.

Reset: A reset line that resets the 8-bit counter 11 upon completion of measurement.

Information is provided to the microcomputer 10 via the following output lines.

Data bus (DB): All measurement results (AI, A2...
) are transmitted to the microcomputer 10 via eight output lines from the 8-bit board 12.

Interrupt (INT) Line: This line sends a line signal (INT) to the microcomputer 10 when a certain connection is present on the boat 12.

Counter 11 counts the number of pulses appearing on line CP2 from clock pulse generator 13. This is attenuation A
There is a way to directly measure 1 in binary.

The optical paths ELC1-3 and RLCI-3 are connected to the control line LC1.
, LC2, and LC3 in the selector/decoder 14 by the microcomputer 10 and becomes available when the counter 11 starts operating from its reset rest position.

The receiver portion of the selector/decoder 14 sends a signal INT to the microcomputer 10 for each position of the vj coin for which the result is read from the boat 12.

When signal INT is present, the contents of boat 12 are latched.

A clock pulse generator 13 supplies an alternating current voltage CP1 to a transmitter or emitter coil CE, which is made into a sine wave by an RC network RCH.

Clock pulse generator 13 loads the counter with clock pulse CP2 when not inhibited by comparator 15. The generator 13 receives the inhibit signal IN from the comparator 15.
Equipped with a pulse width extension device for H.

The count contents of the counter 11 are transmitted to the microcomputer 10 via the boat 12. The contents are latched when the signal INT goes “low”. When the INT line goes “high”
When , the contents of the counter are transmitted directly to the data bus DB.

Digital/analog converter (D/A) +6 is counter 1
The binary content of 1 is converted into an analog signal that is fed to a comparator 15.

At the input of comparator 15, the level of the coil output signal received from coil CR is compared with the DA output signal from D/A converter 16 as shown in FIG.

When the coil output signal is lower than the DA output signal, the comparator output INH will be low. In the rest position, this occurs every negative half-wavelength of the coil output signal. Clock pulse generator 1
The pulse width extension device in 3 covers a period of half a wavelength and the clock pulse CP2 to the counter 11 is inhibited when a long pulse arrives at a short interval (see FIG. 6).

The measurement method is explained in connection with FIGS. 5 and 6.

In the rest mode RM, the level of the DA output signal is preset, and when the content of the counter is zero, the negative half wave of the coil output, which is the received signal, is always lower than the OA output signal. Each time the coil output signal becomes lower than the DA output signal, the output of comparator 15 goes low and clock pulse CP2 to counter 11 is blocked. The pulse width extension device in the clock pulse generator 13 covers the period between negative half-wavelength devices. Counter 11 remains at zero and the DA output signal remains stable.

The voltages of the following outputs are shown schematically: coil output,
The DA output, INH, and CR2° frequencies are not accurate with respect to coin transit time.

The passage of coins between the coils is the energization mode AM, which will be described below. The amplitude of the received coil output signal is attenuated by the influence of the coin between the transmitting coil GE and the receiving coil CR. This means that the negative half-wave of the received signal is no longer below the DA ratio output. As a result, no pulse is detected as the INH signal at the output of the comparator 15.

INI-(signal is stable at high level, clock pulse signal CP2 is no longer inhibited and counter 11
starts counting. The contents of this counter are D/A converter 1
6 into an analog signal. D/A converter 1
Since the binary input of 6 increases, its output signal D
The A output signal also increases.

As seen in FIG. 6, the DA output signal varies according to the attenuated amplitude of the received signal until maximum attenuation is reached. Once the DA ratio output reaches this level, the amplitude of the coil output signal begins to increase and the negative half-wave of the signal falls below the DA ratio output again. As a result, the INH- line starts pulsing again, CR2 is inhibited, and the counter stops at the position reached and remains stable. The contents of the counter are
This is the number that indicates the maximum attenuation for a coin, and the DA output signal remains stable at the maximum attenuation level. The information from boat 12 to the DB line also remains stable at the highest value for a particular coin.

Measurement of the "rate of damping change" is explained in detail below.

In the rest position of the identification device, the counter 11 is reset to zero and a high level signal is applied to the optical selector lines L C1,
5 is given. Selector/decoder 14 provides a signal to the emitter of first optical path ELCI when a coin enters between the coils and starts attenuating the coil output signal. When the coin opens the optical path to the first optical receiver RLC1, the selector/decoder 14 latches the contents of the boat 12;
An INT signal is supplied to the microcomputer 10. The microcomputer reads from the boat 12, stores this result as "first attenuation result" A1, and switches the high level signal from LCl to LC2.

The INT signal disappears, the boat 12 is opened to new data, and EuO3 is turned on. Counter 11 continues to operate so that the coin passes through the coil on its way to the maximum damping position. RuO2 receives the light, the contents of the boat 12 are read out the count of the counter 11 and latched again, the new INT signal causes the microcomputer 10 to read out the boat 12 and store the result as the second attenuation result ゛°A2. and - Switch the high level signal from 1-C2 to LC3. After storing “Third attenuation result” A3, LC
3 high level signal is removed, the INT signal disappears, and the port 12 is again opened to new data.

Microcomputer 10 waits for the maximum attenuation level for a particular coin by checking the contents of counter 11 via boat 12 every 8IIISeC.

When two consecutive measurements show that the contents of the counter are unchanged (different from zero), the contents of the boat are stored as the "maximum attenuation result" (Amax).

After the counter 11 is reset, the high level signal is
It is sent to l and waits for the next coin.

However, emitter ELC1 does not emit light before the new coin begins to attenuate the coil signal.

For an identification device having three optical paths, the results AI are stored in the middle of four as shown in FIG.

A2. A3. and Aff1aX.

FIG. 7 shows the attenuation represented by the coil output signal that occurs during coin passage (AM).

The clock pulse (CP'2> for the counter 11 is
Attenuation measurement value A1. A2. A3. and A+++axtf
i is shown together with the position on the envelope of the resulting coil output signal. The OA output signal goes low as soon as the counter 11 is reset.

Maximum attenuation for one particular coin (A max result)
is correlated with other measured attenuations and depends on the geometry and coin properties (results △1°A2. and A
3), the difference between adjacent results is represented by a much narrower Gaussian distribution curve than for the maximum result A max alone for a random sample. The measured values can be combined in a number of ways. In addition to the three initially measured results (A1°A2. and Amax), two
High selectivity is obtained by using two total sieved values AmaXA3 and A3-A2.

For a coin identification device with three optical paths, the following results must be within preprogrammed tolerance limits:

Maximum Attenuation Result A max First Attenuation Result A1 Second Attenuation Result A2 Correlation Result C1Amax-A3 Correlation Result C2A3-A2 The limit can be set by inserting a random sample of the coin type into the coin identification device. The different measurement results for this sample, characterized by a mean value (/U) and a standard deviation (d), are represented by a Roussian distribution.

Limits for the five results are calculated (eg /U±2d) and stored in EPROM.

By selecting the coins to be sampled, the number of coins in each sample can be reduced to a set limit.

The flowchart of the present invention is expressed as follows.

The counter is reset and the light is turned off.

The unattenuated signal is received by a receiver coil.

The coin goes between the coils.

The signal begins to experience attenuation.

The counter starts counting, not continuously in time but in stages (
Incrementally) increases the count value by attenuation.

Light path 1 is turned on.

Coins block light.

The coin opens a path of light.

The counter status is registered (A1).

Optical path 1 is turned off.

Light path 2 is turned on.

The coin opens a path of light.

The counter status is registered (A2).

Light path 2 is turned off.

The contents of the counter are continuously checked to find the maximum attenuation.

Maximum damping is found.

The counter status is registered (Amax).

The counter is reset.

The registered numbers (A1, A2...Amax) are evaluated individually and/or in combination.

Coins are accepted or rejected.

Preparation for new coins.

Small coins do not block optical path 1 (and 2). Result A1
(And A2> is immediately registered in the counter.

It will be understood that the foregoing detailed description is merely illustrative of one manner of implementing the principles of the invention.

[Brief explanation of drawings]

FIG. 1 shows the general principle of the coin edge detection means for a set of coupled coils, and FIGS.
4 shows the effect of placing the coin edge detector near the top of the coin, and FIG. 5 shows a schematic diagram of the coin identification circuit. 6 shows the voltages of important signals occurring in the circuit of FIG. 5, and FIG. 7 shows Ii!
2 shows intermediately stored results of the cargo identification device. 3.4.5... Optical path, 10... Microcomputer, 11... Counter, 13... Clog, pulse generator, 14... Selector/decoder, 15... Stop calibrator, 16...Digital/analog converter (D/A)
. Applicant's representative Patent attorney Takehiko Suzue (ECR hri・4・

Claims (10)

[Claims] (1) A coin identification method in which a characteristic of a coin is measured by an electromagnetic device and a plurality of measurements are made at different positions of the coin in a passageway, the two or more electromagnetic measurements being made at positions determined by a coin edge sensing means. 1. A coin identification method comprising a coin guide that guides a coin through a passage. 2. The method of claim 1, wherein each measurement includes registering a signal representative of a certain attenuation of the rest mode signal sent from the electromagnetic device. (3) A method according to claim 2, characterized in that the measurement is carried out by reading out a counter that advances by stepwise increases in attenuation. (4) A method according to claim 2, characterized in that attenuation is measured at one or more positions in addition to the maximum attenuation measurement position. 5. A method according to claim 3, characterized in that the counter is started by the coin entering the electromagnetic field of the electromagnetic device. 6. The method of claim 3, wherein one of the coin edge sensing devices reads out one or more counters at a coin location near the top of the coin. (7) A method according to claim 1, characterized in that the measurement is carried out at a position where the "trailing edge" of the passing coin is detected. (8) In a coin identification device comprising an electromagnetic device for measuring a characteristic of a coin, two or more electromagnetic measurements are made at different positions of the coin in the passageway and at positions determined by the coin edge sensing means, the one being measured. A coin identification device comprising one or more coin edge sensing devices disposed near the top of the coin (at least 80% of the diameter of the coin). (9) The coin edge sensing means is arranged such that at least 1% (preferably 1-20%) of the coin area is within the electromagnetic field of the electromagnetic device when the means first senses the coin. The device according to claim 8. (10) The device according to claim 8, wherein the coin edge sensing means is an optical sensor.