JPH0330911B2 - - Google Patents

Description

[Detailed description of the invention]

"Industrial Application Field" The present invention relates to a coin discrimination device. ``Prior art'' Conventionally, the authenticity and denomination of coins in coin depositing and dispensing machines have been determined based on measurement data such as the diameter, thickness, and material of the coin. As the amount of coins in circulation increases, there is an increasing need for precise identification methods, such as methods that read patterns (designs) on the surface of coins. As a conventional example of a technique for reading the surface pattern of this coin, one recorded in the following document is known. ◎ Utility Model Application No. 53-67294 (first conventional example) While moving a coin linearly along a predetermined path,
This device measures changes in magnetic properties caused by differences in surface shape, and uses a measurement line (equivalent to the chord of a circle if a coin is a circle) that is inevitably obtained from the positional relationship between the movement path and the sensor. A technology that compares the change in magnetic properties along the curve with a standard value to determine the change. ◎ Unexamined Japanese Patent Publication No. 51-97496 (Second Conventional Example) An inclined surface (coin and A technology that determines authenticity based on the presence or absence of reflected light from a surface that forms part of a cone with the same center. ◎Special Publication No. 47-45039 (3rd conventional example)
A technology that determines authenticity by measuring the amount of reflected light at a number of measurement points arranged in an arc on the surface of a coin, and comparing the total amount of light with a reference value. "Problems to be Solved by the Invention" However, the above-mentioned conventional techniques have the following problems. ◎ Problems with the first conventional column: Since coins are disk-shaped, there is a possibility that they may be inserted into a coin counting device, discrimination device, etc. in various positions. Patterns for many measurement lines (chords) may be detected. Therefore, it is necessary to store patterns along all strings that may be measured as reference values and sequentially compare these with detection data. The problem is that it requires a huge amount of memory. Further, if the number of reference patterns is limited in consideration of the memory capacity limitation, there will be many cases where there is no reference pattern that corresponds to the measured pattern, and there is a high possibility of misjudgment. ◎ Problems with the second conventional example: The detected pattern does not change depending on the attitude of the coin, so it is a suitable method for identifying coins. It cannot be directly applied to the discrimination of ordinary coins. ◎ Problem with the third conventional example: Since it is not possible to detect surface patterns in a strict sense, even if the patterns are different, as long as the total amount of light is the same, it may be determined to be true. . The present invention was proposed in view of the above circumstances, and
To provide a coin discriminating device which can reliably discriminate a coin having certain irregularities formed on its surface and which requires a small amount of reference data for discrimination which must be measured and stored in advance. The purpose is to "Means for solving the problem" The coin discrimination device according to claim 1 includes:
It consists of a light source and a number of light emitting optical fibers whose base ends are opposed to the light source and whose tips are directed toward the surface of the coin to be measured. A light projector is configured to be arranged at the same pitch in the circumferential direction of the coin to be measured in an inclined state along a conical surface whose axis is a perpendicular line passing through the center of the coin, and a large number of light projectors that convert optical signals into electrical signals consisting of a light-receiving element and a large number of light-receiving optical fibers whose base ends face each of the plurality of light-receiving elements,
The tip of the light-receiving optical fiber is arranged to face a large number of measurement points that are continuously arranged on the surface of the object to be measured along the entire circumference at the same pitch along an arc concentric with the center of the coin to be measured. and a reading device that corrects the electric signal of each light receiving element based on data output from each light receiving element of the reading device when a light source is irradiated onto a homogeneous reflective surface by the light projecting device. a correction circuit that corrects optical non-uniformity of the light-receiving elements; and a correction circuit that outputs an output from each light-receiving element of the reading device when the surface of the coin to be measured is irradiated with light by the light projector. A storage means in which a data group of corrected electrical signals is written as a measurement data string arranged corresponding to the arrangement of the measurement points, the storage means being written as a reference by a device having the same configuration as the light projecting device and the reading device. A storage means in which a reference data string corresponding to the measurement data string measured on a coin is written in advance; and a storage means that controls the storage means to uniformly arrange each data in either the reference data string or the measurement data string. The coin is characterized by being equipped with a central processing unit that repeatedly compares the reference data string and the measured data string while shifting the coin one by one to determine the identity of the reference coin and the coin to be measured. The coin discrimination device according to claim 2 comprises a light source and a large number of light emitting optical fibers whose base ends face the light source and whose tips face the surface of the coin to be measured. A light emitting device configured such that the tip of the light emitting optical fiber is arranged at the same pitch in the circumferential direction of the coin to be measured, with the tip part of the light emitting optical fiber being inclined along a conical surface whose axis is a perpendicular line passing through the center of the coin to be measured. a device, a large number of light-receiving elements that convert into optical signals and electrical signals, and a large number of light-receiving optical fibers whose base ends face each of the plurality of light-receiving elements,
The tips of the light-receiving optical fibers are opposed to a large number of measuring points that are continuously arranged on the surface of the coin to be measured along a circular arc that is concentric with the center of the coin to be measured at the same pitch over a part of the entire circumference. a reading device configured to allow each light-receiving element to be detected based on data output from each light-receiving element of the reading device when a light beam is irradiated onto a homogeneous reflecting surface by the light projecting device; a correction circuit that corrects optical non-uniformity of each light-receiving element by correcting the electrical signal of the light-receiving element; storage means in which the data of the electric signal corrected by the correction circuit is written as a measurement data string arranged in correspondence with the arrangement of the measurement points, the storage means having the same configuration as the light projecting device and the reading device; a storage means in which a reference data string corresponding to the measurement data string measured on the reference coin by an apparatus in which the light-receiving optical fibers are continuously arranged over the entire circumference is written in advance; A continuous portion of the data string consisting of the same number of data as the measurement data string and the measurement data string are shifted by one data portion within the entire reference data string by controlling the storage means. The present invention is characterized in that it is equipped with a central processing unit that determines whether the reference coin and the coin to be measured are the same by selecting them, repeating the selection, and repeatedly comparing them. "Operation" The coin discrimination device according to claim 1 has the following features:
The state of irradiation of light from the light projector to the surface of the coin to be measured is uniform with respect to the center line of the coin to be measured, so even the center line of the coin to be measured is not aligned with the light projector. Regardless of its orientation, if it is placed in a certain position, a certain shadow will appear at the same position on its surface, depending on the unevenness of that position. Therefore, the electrical signal output to each light-receiving element of the reading device is the shadow of the measurement point of the coin to be measured where the tip of the optical fiber whose base end faces the light-receiving element is located, that is, the measurement corresponding to that light-receiving element. This is data on the unevenness of the points. Therefore, the reference data string and the measured data string to be written into the storage means are a plurality of measurement points arranged in a circumferential ring at the same position on the surface of the reference coin or the surface of the coin to be measured at the same pitch. It is a set of data of unevenness in . Moreover, these data strings are arranged in the same order as the measurement points to which the individual data corresponds, that is, if the data are data on the unevenness of adjacent measurement points on the coin surface, they are considered to be adjacent within the data string. There is. (Here, "data adjacent" refers to a conceptual arrangement that determines how individual data correspond when comparing a reference data string and a measured data string.
Specifically, it is an arrangement that is given meaning by the number of the memory area of the storage means in which each piece of data is stored. ) Therefore, regardless of the coin's orientation at the time of measurement (its orientation in the direction of rotation around a center line perpendicular to its surface), data can be stored while maintaining this adjacency relationship within either data column. By moving (that is, shifting) the arrangement, all pairs of data to be matched when comparing both data strings will be measured at approximately the same position on the reference coin surface or the measured coin surface. becomes. Therefore, if the coin to be measured and the reference coin are identical, in the comparison between the reference data string and the measured data string in this method, most of the data shift will be completed once. There will always be a case where all the data match with a small error, so
The coin can be reliably identified based on whether or not this data matches. Moreover, as the reference data, it is only necessary that the number of data corresponds to one row of measurement points arranged on the surface of the reference coin as described above. Furthermore, since this device is provided with a correction circuit for correcting optical non-uniformity of the light-receiving elements, it is possible to accurately discriminate coins even if there is non-uniformity in the characteristics of a large number of light-receiving elements. For example, if there is optical non-uniformity in each light receiving element,
The light emitting device of this device irradiates a homogeneous reflective surface with a light beam, and each signal output from each light receiving element of the reading device of this device has a difference depending on the non-uniformity. The non-uniformity can be corrected by registering in advance and adding or subtracting this when measuring the coin to be measured. Furthermore, according to the coin discrimination method described in claim 2, the reference coin is measured at measurement points arranged on a part of the entire circumference, so that the coin discrimination device can be made smaller and the discrimination time can be reduced. Even in this case, as long as the reference coin surface has irregularities that vary widely in the circumferential direction, highly reliable coin discrimination can be performed in the same way as the device described in item 1 above. I can do it. ``Example'' The present invention will be described below based on an example of a coin discrimination device shown in the drawings. 1 to 9 show a first embodiment of a coin discriminating device, and this coin discriminating device uses a light projecting device 1 to detect the surface of a coin C to be measured as shown in FIGS. 1 to 7. The light receiving device 2 reads the shadow, and then the signal read by the light receiving device 2 is sent to the correction circuit 1 shown in FIG.
The basic configuration is such that the discrimination is made by the discrimination circuit 3 via 0. The light projecting device 1 is composed of a light source 4 and a light projecting optical fiber 5 that guides the light beam emitted from the light source 4 to the surface of the coin C to be measured.
is arranged along a direction intersecting an axis passing through the center of the coin C and a direction intersecting an arc 6 concentric with the coin C to be measured, that is, along a conical surface having the axis as an axis. has been done. The light emitting optical fiber 5 is arranged at measurement points P1 to _P1 arranged at a constant pitch in the circumferential direction of the circular arc 6, as shown in FIG.
n of P _2o (for example, P ₁ ~ _{P o} or P ₃ ~
P _o+2 ) is emitting a ray of light. The light receiving device 2 also includes a light receiving array ΣR (light receiving elements R ₁ to R _o ) and a large number (n) of light receiving elements that transmit the shadow appearing on the surface of the coin C to the light receiving elements R ₁ to R _o , respectively. It is composed of an optical fiber 7. The tip 7a of the light-receiving optical fiber 7 is located opposite the light-receiving elements R ₁ to _Ro .
As shown in the figure, they are arranged in a straight line, and one end part 7b
As shown in FIG. 4, they are arranged so as to be perpendicular to the circular arcs 6 on the coin C to be measured, that is, along a conical surface whose axis is a straight line perpendicular to the center of the coin C to be measured. The tip portion 7b of each light-receiving optical fiber 7 is opposed to a part of the measurement points P ₁ to _{P 2o} (for example, P ₁ to _{P o} or P ₃ to _{P o+2} ), and The shading at ₁ to P _2o is measured. Therefore, in this first embodiment, there are 2n measurement points P ₁ to P _2o over the entire circumference of the coin C to be measured.
Measurements will be taken at n locations, that is, over half the circumference. When the optical fiber 5 for storage of the coin device 1 emits light onto the coin C to be measured as shown by the arrow in FIG. 7, when the coin C to be measured is in the position shown in FIG. In any case where C is in the position shown in FIG.
is read by the light receiving array ΣR via the light receiving optical fiber 7. Next, the half-separated circuit 3 will be explained with reference to FIG. Errors caused by uneven quality and processing precision of the optical fiber for receiving light are now corrected. For example, each light receiving element R ₁
If there is optical non-uniformity in ~R _o , the light emitting device 1 of this device irradiates a homogeneous reflective surface with a light beam, and the light is output from each light receiving element R ₁ ~ _{R o} of the light receiving device 2 of this device. There will be a difference in each signal depending on this non-uniformity, so if this difference is registered in advance in a memory etc. connected to the correction CPU 10a and this value is added or subtracted when measuring the coin to be measured, the above-mentioned non-uniformity can be corrected. It can be corrected. Then, the discrimination circuit 3 AD
A CPU 13 connected to the converter 11 and an interface 12, and a CPU 13 connected to the CPU 13
It is composed of RAM 14 and ROM 15. The ROM 15 stores reference data of measurement points P ₁ to P _2o (see Fig. 6) over the entire circumference of the reference coin CS.
m ₁ ~ _{m 2o} are memorized and these reference data
m ₁ to m _2o are as shown in the i=1 column of Table 1,
They are read in correspondence with addresses A ₁ to _{A 2o} of the RAM 14, respectively. In addition, the A ₁ of this RAM 14
Measurement data d ₁ to _{d o} of the light receiving array ΣR are stored in addresses other than ~A _2o .

[Table] In addition, the correction circuit 10 includes a correction CPU 10
a, interface 10b, and DA converter 1
0c and an arithmetic unit 10 for the correction.
For example, measurement data obtained by the light receiving device 2 when a light beam is irradiated from the light projecting device 1 onto a uniform reflective surface is stored in the CPU 10a as a digital signal. Therefore, if there is a processing error or non-uniformity in the material of the optical fiber, the signal that has become non-uniform due to these causes is stored in the correction CPU 10a as correction data. Then, the data stored in the correction CUP 10a is converted into an analog signal by the DA converter 10c, and this data and the measurement data of the coin C to be measured are calculated by the calculator 10d (for example, the measurement data is converted into correction data). ), the projection device 1
The amount of irradiated light and the non-uniformity of the light receiving sensitivity of the light receiving device 2 are corrected. Next, the operation of the discrimination circuit 3 will be explained with reference to FIG. Note that in the following explanation, SN indicates the Nth step. S1: Start S2: The light-receiving array ΣR reads data d1 _{to d0} at n consecutive points in the circumferential direction among the measurement points _P1 to P2n of the coin C to be measured and stores them in the RAM 14. S3: Assign 1 to i. S4: Compare d ₁ to d _o and the data in A ₁ to _{A o} (for i=1, A ₁ = m ₁ , A ₂ = m ₂ ... A _o = m _o ), and compare both. Compare data and find matches. S5: Whether or not a predetermined degree of agreement is satisfied (for example, a degree of agreement of 95% means that 95% of the data within A ₁ to _{A o} and the measured data d ₁ to _{d o} agree). Judgment is made, and if the predetermined degree of matching is satisfied, go to S6.
If not satisfied, proceed to S7. S6: Generate an Accept signal, that is, a signal indicating that the coin can be accepted. S7: Substitute i=i+1. S8: Determine whether or not i≦2n, that is, whether or not the discrimination operation has been performed a predetermined number of times. In other words, if the determination operation has been performed a predetermined number of times, in other words, the degree of coincidence has reached the predetermined value 2n times in a row. If it is below, the process proceeds to S9 and a Non-Accept signal, that is, a signal indicating that coins can be accepted, is generated. Further, if the determination operation has not been performed a predetermined number of times, the process advances to S10. S10: As shown in Table 1, i=i+1
As increases, the data in address A ₁ is moved to address A _2o , and the j-th address (for example, data at address A _2o ) is sequentially moved to the j-1 address (for example, address A _2o-1 ). Return to S4. Below, the operation will proceed through S4, S5, S6, S4, S5, S7, S8, S9 and reach S11, or S4, S5, S7, S8,
Repeat the operation of S10. S11: Operation completed. Furthermore, if the above operation becomes acceptable,
Standard data m′ ₁ for other aspects of standard coin CS ~
It is sufficient to compare m′ _2o and the measurement data d ₁ to _d o using S1 to S11, and exclude only coins that are determined to be Non-Accept on both sides of the coin. In addition, in the above operation, only the authenticity is determined, but it is also possible to discriminate the metal by repeating the above operation for reference data of coins of each metal. Next, the operation of the discrimination circuit according to the second embodiment of the coin discrimination device will be explained with reference to FIG. Note that the ROM of this discrimination circuit contains the reference data.
(3n-1) addresses A ₁ ~ for m ₁ ~ m _2o
A _3o-1 , and these addresses A ₁ to _{A 3o-1} include
As shown in Table 2, data of m ₁ to m _2o and m ₁ to m _o-1 are stored. Further, measurement data d ₁ to d _o are stored in the RAM.

[Table] S21: Start S22: Measurement point P ₁ of coin C by light receiving array ΣR
_-P2o , data _d1 - _d0 of n consecutive locations in the circumferential direction are read and stored in the RAM 14. S23: Substitute i=0. S24: Determine the degree of coincidence between the measured data d ₁ to d _o and the reference data (for example, m ₁ to _{m o} ) of the addresses A _1+i to _{A o+i} . S25: Determine whether or not a predetermined degree of matching (for example, 95%) is satisfied, and if satisfied, proceed to S26; otherwise, proceed to S27. S26: Generates an Accept signal. S27: Substitute i+1 for i. S28: Determine whether i<2n, that is, whether the determination operation has been performed a predetermined number of times, and if NO,
Proceed to S29 and generate a Non-Accept signal,
If YES, return to S24. Then, while adding i one by one, the comparison between the reference data and the measured data within addresses A _1+i to A _2+i is repeated. S29: If the determination operation is performed 2n times without satisfying the predetermined degree of coincidence, a Non-Accept signal is generated. S30: Operation completed. Furthermore, if the above-mentioned operation results in a non-acceptable coin, as explained in the first embodiment, the standard data and measured data for the other sides of the standard coin CS are compared, and non-acceptance is determined for both sides of the coin. It is sufficient to exclude those determined as Accept. Note that the coin discrimination method according to the present invention is not limited to the above-mentioned embodiments, and can also be implemented in the following embodiments, for example. (i) In each of the above embodiments, measurements were taken over approximately half the circumference along the arc of the coin to be measured (that is, 2n pieces of reference data and pieces of measurement data were compared). The unevenness of the surface of the coin to be measured may be measured over the entire circumference and this data may be used to similarly discriminate the coin, or the coin may be similarly discriminated by measuring any part of the arc. Good too. That is, the number of measurement points on the surface of the coin to be measured may be appropriately set in consideration of discrimination accuracy depending on the degree of unevenness of the coin surface. (ii) Detecting the attitude of the coin to be measured, correcting either the reference data or the measured data using this detection signal, then comparing both data, and omitting the operation of shifting the data in the circumferential direction of the arc. . "Effects of the Invention" As is clear from the above explanation, according to the coin discriminating device recited in claim 1, regardless of the attitude of the coin at the time of measurement, if the coin has certain irregularities on its surface, This has the effect of allowing reliable discrimination. Moreover, as the reference data, it is only necessary that the number of data corresponds to one row of measurement points arranged on the surface of the reference coin as described above. Further, this device is provided with a correction circuit for correcting optical non-uniformity of the light-receiving elements, so that even if there is non-uniformity in characteristics of a large number of light-receiving elements, coin discrimination can be performed with high accuracy. Moreover, according to the coin discrimination method recited in claim 2, the reference coin is measured only at measurement points arranged on a part of the entire circumference, so it is possible to downsize the coin discrimination device or In this case, as long as the reference coin surface has irregularities that vary widely in the circumferential direction, it is possible to achieve highly reliable coin discrimination similar to the device described in item 1 above. It can be performed.

[Brief explanation of drawings]

1 to 9 show a first embodiment of a coin discrimination device to which the present invention is applied. FIG. 1 is a side view of a light projecting device and a light receiving device, and FIG. 3 is a perspective view showing the arrangement of optical fibers for light emission and light reception, FIG. 4 is a view taken along the - line in FIG. 1, and FIG.
Fig. 6 is an explanatory diagram of the measurement points, Fig. 7 a and b are explanatory diagrams of the operation of the projecting device, Fig. 8 is a block diagram of the discrimination circuit, and Fig. 9 is a diagram taken along the - line in the figure. Flowchart showing the operation of the discrimination circuit. FIG. 10 is a flowchart showing the operation of the discrimination circuit according to the second embodiment of the coin discrimination device. 1...Light emitter, 2...Reader (light receiver), 3...Discrimination circuit, 4...Light source, 5...Optical fiber for light emission, 6...Circular arc, 7... Optical fiber for light reception, 8... Convex portion, 9... Shadow, 10... Correction circuit, 10a... Correction CPU, 10b... Interface, 10c... DA converter, 10d...
...Arithmetic unit, 13...Central processing unit (CPU), 1
4, 15...Storage means, (14...RAM, 15
...ROM), C... Coin to be measured, CS... Standard coin, A ₁ - A _3o ... Address, d ₁ - d _o ... Measurement data, m ₁ - _{m 2o} ... Standard data, P ₁ - P _2o ...Measurement point, ΣR...Photodetector array, _R1 ~ _Ro ...Photodetector.

Claims (1)

[Claims] 1. Consists of a light source and a number of light emitting optical fibers whose base ends face the light source and whose tips are directed toward the surface of the coin to be measured. A light projecting device configured to be arranged at the same pitch in the circumferential direction of a coin to be measured with its tip end inclined along a conical surface whose axis is a perpendicular line passing through the center of the coin to be measured, and an optical signal. It consists of a large number of light-receiving elements that convert into electrical signals, and a large number of light-receiving optical fibers whose base ends face each of the plurality of light-receiving elements,
A configuration in which the tips of the light-receiving optical fibers are respectively opposed to a large number of measurement points that are continuously arranged on the surface of the coin to be measured along the entire circumference at the same pitch along an arc that is concentric with the center of the coin to be measured. a reading device configured to be a light beam, and correcting the electric signal of each light receiving element based on data output from each light receiving element of the reading device when a light beam is irradiated onto a homogeneous reflective surface by the light projecting device. In addition, a correction circuit corrects optical non-uniformity of each light-receiving element, and a correction circuit that outputs light from each light-receiving element of the reading device when the hardened surface to be measured is irradiated with light by the light projector and corrects the optical non-uniformity of each light-receiving element. storage means in which a data group of electrical signals corrected by the above correction is written as a measurement data string arranged in correspondence with the arrangement of the measurement points, the storage means being written by a device having the same configuration as the light projecting device and the reading device; A storage means in which a reference data string corresponding to the measurement data string measured for reference curing is written in advance; and a storage means that controls the storage means to arrange each data in either the reference data string or the measurement data string. It is characterized by comprising a central processing unit that repeatedly compares the reference data string and the measured data string while shifting them one by one to determine the identity of the reference coin and the coin to be measured. Coin recognition device. 2 Consists of a light source and a number of light emitting optical fibers whose base ends are opposed to the light source and whose tips are directed toward the surface of the coin to be measured; A light projecting device is arranged at the same pitch in the circumferential direction of the coin to be measured in an inclined state along a conical surface whose axis is perpendicular to the center of the coin, and a large number of light signals are converted into electrical signals. a light-receiving element, and a large number of light-receiving optical fibers each having a base end facing each of the plurality of light-receiving elements,
The tips of the light-receiving optical fibers are arranged opposite to a large number of measurement points that are continuously arranged on a part of the entire circumference of the same pitch along an arc concentric with the center of the coin to be measured on the surface of the coin to be measured. a reading device having a configuration that allows the light projecting device to emit a light beam onto a homogeneous reflective surface; a correction circuit that corrects optical non-uniformity of each light-receiving element by correcting it; and a correction circuit that corrects optical non-uniformity of each light-receiving element; A storage means in which the data of the electrical signal corrected by the circuit is written as a measurement data string arranged in correspondence with the arrangement of the measurement points, the device having the same configuration as the light projecting device and the reading device. a storage means in which a reference data string corresponding to the measurement data string measured on the reference coin by the light-receiving optical fibers continuously arranged over the entire circumference is written in advance; A continuous portion of the data string consisting of the same number of data as the measurement data string and the measurement data string are shifted by one data portion within the entire reference data string by controlling the storage means. A coin discriminating device comprising a central processing unit that discriminates the identity of a reference coin and a coin to be measured by repeatedly selecting and comparing the coins.