JP3425174B2 - Coin identification device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coin discriminating apparatus for discriminating types of coins to be conveyed, for example, in a coin processor for sorting coins by type. 2. Description of the Related Art Conventionally, for example, in a coin processing machine for sorting coins by type, coins of mixed denominations to be sorted are stored in a hopper, and coins are fed one by one by a coin feeding device. The coin is fed and conveyed by a coin forcible conveying means such as a conveying belt, and in the middle of the conveyance, a coin discriminating device including an optical sensor and a magnetic sensor, etc., is used to identify the denomination and authenticity of the conveyed coin. The coins to be conveyed are selected by a coin sorting device based on the identification result, and stored in a stacker of a corresponding denomination. In such a coin processing machine, a coin discriminating apparatus for discriminating a type of coin and the like includes a first magnetic sensor of a surface shielding magnetic flux detection type for detecting a hole of a coin from an upstream side of a coin conveying path. CCD type line sensor (photoelectric conversion element) for detecting the outer diameter of the coin by detecting the light-shielded area by the coin, and the transmitted magnetic flux detection type for detecting the material, diameter and thickness of the coin comprehensively Two magnetic sensors are sequentially arranged, and the type of coin and the like are identified from the maximum value of the output signal of each sensor and the hole detection result of the first magnetic sensor. In this case, of course, the width of the coin transport path is
A coin with the largest diameter (for example, 500 yen and an outer diameter of 2
(6.5 mm), coins having a small outer diameter are conveyed while being displaced in a direction perpendicular to the conveying direction. [0005] The first magnetic sensor is:
No matter where the coin with the smallest diameter passes on the transport path, the hole is located at the center of the transport path so that the hole can be detected reliably.
Therefore, the present magnetic sensor can identify the material of the coin, but if the transport position of the coin varies as described above, the maximum output value naturally also varies. The second magnetic sensor is a sensor of a transmitted magnetic flux detection type as described above, and detects a transmitted magnetic flux in a direction orthogonal to the coin transport path. A coil and a base core were provided. Therefore, in the present magnetic sensor, the distribution of the magnetic flux generated from the primary coil for magnetic excitation becomes denser toward the end of the base core and becomes coarser toward the center, and the distribution of magnetic flux in the direction orthogonal to the transport direction is not uniform. Was. Further, the side core above the transport path having the secondary coil for detecting the transmitted magnetic flux has a structure in which the central portion is opened because of the coin transport belt, and the detection ability of the transport path central portion is inevitably reduced. Further, depending on the mounting accuracy of each sensor, etc.
The output of each sensor will vary slightly depending on the coin transport position, and as a result, the judgment reference value for coin identification will be broad and rough, including all of these variations, and will include foreign coins and fake coins. In addition, coins with severe wear and scratches cannot be rejected, and there is a problem that the inspection ability is insufficient. Therefore, an object of the present invention is to provide a coin discriminating apparatus having high discrimination accuracy regardless of a coin transport position. [0008] A coin discriminating apparatus according to the present invention comprises at least one magnetic sensor provided along a transport path for transporting coins to be identified, and a magnetic sensor along the transport path. Are disposed in parallel with the direction of conveyance of the coin,
A line sensor for detecting a light-shielded state by the conveyed coin, a signal corresponding to a portion of the effective pixel portion of the line sensor which is shielded by the conveyed coin, and a signal generated corresponding to one pixel of the line sensor. And a diameter detecting means for detecting the diameter of the coin by counting the result as an effective pulse and successively comparing the result with the pulse to determine the maximum value as the diameter of the coin, and the line sensor. Generated corresponding to one pixel of the line sensor corresponding to a portion shielded by the conveyed coin in the effective pixel portion of the line sensor during a predetermined time from a detection start position at which the detection operation is started. counting pulses, by performing a calculation of subtracting the count value from <br/> the predetermined time is the transport Transport position detecting means for detecting the transport position of the coin, correcting means for correcting at least the output of the magnetic sensor according to the transport position of the coin detected by the transport position detecting means, and storing a determination reference value in advance The type of the coin and the like are determined by comparing the storage means and the diameter of the coin detected by the diameter detection means and the output of the magnetic sensor corrected by the correction means with the determination reference value in the storage means. Determining means for performing the determination. According to the present invention, the position of a conveyed coin is detected, and at least the output of the magnetic sensor is detected in accordance with the detected position of the conveyed coin.
By correcting the force , coins can be identified with high accuracy regardless of the coin transport position. An embodiment of the present invention will be described below with reference to the drawings. FIGS. 2 and 3 show a configuration of a coin discriminating apparatus which is provided, for example, in a conveyance path of a coin processing machine and discriminates a coin denomination and authenticity. In the figure,
Coins 1 fed one by one from a coin feeding unit (not shown)
Is forcibly conveyed in the direction of the arrow shown in the figure while being guided on the conveyance path 2 and pressing the central portion onto the conveyance path 2 by the conveyance belt 3. A first magnetic sensor 5 is provided in the middle of the transport path 2 at the center in the width direction with a ceramic plate 4 interposed therebetween. The first magnetic sensor 5 is for magnetically detecting the hole and the material of the coin 1. In front of the first magnetic sensor 5, a coin detecting sensor 6 including a light emitting diode and a light receiving element for detecting the conveyed coin 1 is provided.
Is provided, and after the coin detecting sensor 6 detects the coin 1, the discriminating operation of the coin 1 is started. In front of the first magnetic sensor 5, a diameter detecting sensor 7 for optically detecting the diameter of the coin 1 is provided, and in front of the diameter detecting sensor 7, the coin 1 is provided. Second for magnetically detecting the material, diameter and thickness of the
Are provided. FIG. 4 shows the structure of the first magnetic sensor 5. The first magnetic sensor 5 is a known differential transformer type magnetic sensor. That is, the center core 2
1, a primary coil 22 for excitation wound around a central portion in the longitudinal direction, two secondary coils 23 and 24 respectively wound on both ends of the primary coil 22, and a center core 2
1 and a ring core 25 fixed to the outer peripheral portion of the center core 21 to form a magnetic path. The primary coil 22 is excited by a sine wave signal from a sine wave oscillator 26, and the secondary coils 23, 24
Are electromagnetically induced from the primary coil 22 to generate an output, but are connected so as to cancel each other. Thus, when the coin 1 is not on the sensor, the output is almost zero. However, since they are not completely canceled in practice, an output having a very small value is generated, and this is hereinafter referred to as an offset. When the coin 1 comes on the sensor, the balance of the induced voltage between the secondary coils 23 and 24 is lost and a differential output is generated. This is because the eddy current generated on the surface of the coin 1 pushes the magnetic flux near the coin 1 downward, so that the induced voltage of the secondary coil 23 on the coin 1 side decreases. As is well known, the AC loss varies depending on the material of the coin 1. That is, since the conductivity of a white copper coin, a bronze coin, and an aluminum coin is different, they are all different. FIG. 5 shows the structure of the second magnetic sensor 8. The second magnetic sensor 8 is also a known magnetic sensor. That is, the entire main body 31 is molded and integrated with resin or the like, but the central portion through which the coin 1 and the transport path 2 to be detected pass and the upper central portion through which the transport belt 3 enters and exits. The part is open. A primary core (base core) 32 located below the transport path 2 has a primary coil 33 for excitation, and
First secondary coil 3 electromagnetically induced from primary coil 33
4 are wound. On the other hand, secondary cores (side cores) 35, which are arranged above and below the transport path 2 and are separated from each other at the center,
A second secondary coil 37, 38 is wound around 36, and the secondary coil 37, 38 detects a magnetic flux generated from the primary coil 33 and transmitted through the coin 1. ing. The primary coil 33 is excited by a sine wave signal from a sine wave oscillator 39. With such a configuration, the primary coil 3
The magnetic flux generated from 3 becomes closer to the end of the primary core 32 and becomes coarser toward the center. Also,
The secondary cores 35 and 36 having the secondary coils 37 and 38 for detecting the generated magnetic flux have a structure in which a central portion is opened for the transport belt 3. For this reason, the detection capability at the central portion of the transport path 2 is reduced, the sensor output greatly varies depending on the transport position of the coin 1, and the detection accuracy is deteriorated. FIGS. 6 and 7 show the structure of the diameter detecting sensor 7. FIG. That is, a slit 41 that is longer than the maximum diameter of the coin 1 is provided in the middle of the transport path 2 in a direction orthogonal to the transport direction of the coin 1.
On the lower side of the transport path 2 opposed to 1, for example, a rod-shaped light source 42 in which a number of light emitting diodes are arranged in parallel is provided. Above the transport path 2 facing the slit 41, a CCD line sensor 44 as a photoelectric conversion element is provided via a rod- shaped lens ( rod lens array ) 43. With such a configuration, the light from the light source 42 passes through the slit 41, the portion of the coin 1 is blocked, and the lens 4
3 and the coin 1 on the light receiving surface of the line sensor 44.
It comes to connect the shadow of. In such a configuration, the line sensor 4
As shown in FIG. 8, the output of the signal No. 4 starts from a high level, and the falling edge of the output triggers the detection operation. First, although several pixels are invalid, a predetermined pixel becomes an effective pixel, and in this effective pixel portion, a portion where light from the light source 42 is blocked becomes dark and becomes a high level. Usually, the coin diameter is detected by counting the number of pixels in the high-level portion of the effective pixel portion with a counter. In this embodiment, the number of pixels from the trigger position to the start of darkness is counted by another counter, or the number of effective pixels from the trigger position to a predetermined time T3 is counted. 1 is detected. FIG. 1 shows an overall control circuit. First, the system of the first magnetic sensor 5 will be described.
The differential outputs from the secondary coils 23 and 24 are amplified by an amplifier (eg, a differential amplifier) 51 and then amplified by a capacitor 5.
The DC component is cut by 2, full-wave rectified by the full-wave rectifier circuit 53, smoothed by the low-pass filter 54, and input to the channel 0 of the A / D converter 55. Next, the system of the second magnetic sensor 8 will be described. Outputs of the secondary coils 34, 37, and 38 are supplied to amplifiers (eg, differential amplifiers) 56, 60, and 64, respectively.
, The DC component is cut by capacitors 57, 61, 65, full-wave rectified by full-wave rectifier circuits 58, 62, 66, smoothed by low-pass filters 59, 63, 67, and input to arithmetic circuit 68. Is done. The arithmetic circuit 68 performs, for example, the following processing: Vout = A56 * [A60 * V59-A64 * (V63 + V67)]
t is input to channel 4 of the A / D converter 55. Here, V59 is the output of the low-pass filter 59, V63 is the output of the low-pass filter 63, and V67 is the low-pass filter 6
7, A56 is the amplification factor of the amplifier 56, A60 is the amplifier 6
The amplification factor of 0 and A64 is the amplification factor of the amplifier 64. The low-pass filters 59, 63, 67
Are also directly input to the A / D converter 55, respectively. That is, the output of low-pass filter 59 is on channel 1, the output of low-pass filter 63 is on channel 2, the output of low-pass filter 67 is on channel 3,
Each is entered. The A / D converter 55 includes a CPU 70 described later.
The switching of the channel is controlled by the multiplexer 69 controlled by the low pass filter 5.
4, 59, 63, 67 and the respective outputs of the arithmetic circuit 68 are converted into digital signals. The A / D converter 55 has channels 0,
The input signal levels of 1, 2, 3 are set to amplifiers 51, 56,
Since each of the amplification factors 60 and 64 can be adjusted, they are set to predetermined values in advance. A /
The operation circuit 6 sets the input signal level of the channel 4 of the D converter 55 to “0” when no coin is present on the sensor.
8 has been adjusted. The output of the A / D converter 55 is input to a CPU (Central Processing Unit) 70 as output data of the first and second magnetic sensors 5 and 8. C
The PU 70 alternately switches the channels 0 and 4 of the A / D converter 55 via the multiplexer 69 at the time of identifying the coin 1, and thereby outputs the output of the first magnetic sensor 5 and the output of the second magnetic sensor 8. Reading (sampling) alternately,
They are separately and sequentially stored in a RAM (random access memory) 71. The CPU 70 includes amplifiers 51, 56,
When adjusting the amplification factors 60 and 64, the multiplexer 6
9, channels 0, 1, 2, 2 of the A / D converter 55.
3 is sequentially switched, the outputs of the secondary coils 23, 24, 34, 37, and 38 of the first and second magnetic sensors 5 and 8 are sequentially read to control the adjustment of the amplification factor. . The CPU 70 includes a ROM (Read Only Memory) 72 which stores magnetic coin diameter determination reference value data and the like for each coin denomination in the form of a table, and a coin diameter as described above. A diameter detection counter 73 that counts for detection and a position detection counter 74 that counts for detecting the transport position of the coin 1 in a direction perpendicular to the transport direction are connected. The CPU 70 further includes a signal processing unit 75
The output of the line sensor 44 is input via the. Accordingly, the CPU 70 performs the above-described optical coin diameter detection processing, coin conveyance position detection processing, and the like based on the output of the line sensor 44. In addition to the coin identification processing and the amplification factor adjustment control of the amplifier, the CPU 70 performs a hole detection processing and a material detection processing of the coin based on the output of each magnetic sensor, and further, the trueness of the coin based on the identification result thereof. A false discrimination process and the like are also performed, and control of the entire control system such as a control process of various actuators of the coin processing machine based thereon is performed. Next, the operation of the above configuration will be described. First, the output process of the first magnetic sensor 5 will be described. Secondary coils 23 and 24 of first magnetic sensor 5
Is amplified by the amplifier 51,
The DC component is cut by the capacitor 52 and the full-wave rectifier circuit 5
3 is full-wave rectified, smoothed by a low-pass filter 54,
After being converted to a digital value by the A / D converter 55, the CPU
70, and is used for detecting the hole and material of the coin 1 and the like. Next, the diameter detecting process by the diameter detecting sensor 7 will be described. Line sensor 4 of diameter detection sensor 7
The output 4 outputs a high-level signal only in the portion where light is blocked as described above. Therefore, the CPU 70 calculates the logical product of the high-level signal of the effective pixel portion and the pulse generated corresponding to one pixel, sets the result as an effective pulse, and counts the number of effective pulses by the counter 73. By detecting the diameter of the coins 1 and successively comparing them, the maximum value is stored in the RAM 71 as storage means.
To memorize. The CPU 70 detects the transport position of the coin 1 based on the output of the line sensor 44. That is, a pulse (coin position pulse A, see FIG. 8) corresponding to the pixel from the trigger position to the start of darkness (start of shading) is generated, and the number of pulses is counted by the position detection counter 74, or Predetermined time T from position
Pulses corresponding to up to three valid pixels (coin position pulse B, see FIG. 8) are generated, and the number of pulses is counted by the position detection counter 74 to detect the transport position of the coin 1. Next, the output processing of the second magnetic sensor 8 will be described. The secondary coil 34 of the second magnetic sensor 8
The outputs of 37 and 38 are processed in the same manner as the first magnetic sensor 5, and then input to the arithmetic circuit 68, where the above-described arithmetic processing described above is performed. Vout = A56 * [A60 * V59-A64 * (V63 + V67)] The operation output Vout is obtained by the A / D converter 55
Is converted into a digital value, and is input to the CPU 70. The CPU 70 detects the maximum value by sampling the output of the A / D converter 55 at predetermined intervals and successively comparing them, and stores the maximum value in the RAM 71 as a storage unit. When the maximum value of each sensor is thus detected and stored in the RAM 71, the CPU 70 reads the criterion value data stored in advance in the form of a table in the ROM 72, and reads the criterion value data. The predetermined width is corrected based on the coin transport position detected as described above. Then, the CPU 70 compares the corrected determination reference value data with each of the maximum values stored in the RAM 71 to determine to which range each sensor output belongs, and sums up the determination results. By the determination, the type of the coin 1 and the authenticity are identified. Next, an actual detection value correction method will be described with reference to FIG. Output [V] of the second magnetic sensor 8
As described above, the level varies depending on the transport position of the coin 1 as described above. This is remarkable for a small-diameter coin, for example, a one-yen coin. As shown in FIG. 9, for a one-yen coin, the output level decreases as the coin passes through the central portion of the transport path 2. Suppose that coin 1 is moved from one end of transport path 2 to X
[Mm], the output value Vctr when passing through the center of the transport path 2 is calculated by performing the following calculation.
To be corrected. Vctr = Vx-a * (d / 2-X) where Vctr is the output value when passing through the center of the transport path 2, and Vx is X [m from one end of the transport path 2.
m], a is the output correction coefficient, and d is the width of the transport path 2. The output correction coefficient a differs depending on the diameter of the coin 1. Therefore, after detecting the maximum value of the diameter based on the output of the line sensor 44, the output correction coefficient a is set. As described above, by performing the output correction of the second magnetic sensor 8, the same output as when the coin 1 always passes through the central portion of the transport path 2 is obtained no matter where the coin 1 passes. Accuracy is greatly improved. Although the first magnetic sensor 5 is not as large as the second magnetic sensor 8,
Similarly, since the output varies, the same correction as described above may be performed. The above-described correction using the output correction coefficient is effective when the output fluctuation characteristic can be approximated linearly or linearly, but is extremely troublesome when the output variation characteristic can be approximated only by a complicated function. So, in such a case,
For example, for each position from one end of the transport path 2, the determination reference value data tabulated is stored in the ROM 72, and when the transport position of the coin 1 is detected, the determination reference value corresponding to the transport position is detected. Data may be selected and used. FIG. 10 shows an example of judgment reference value data tabulated in this case. For example, there are six types of judgment reference value data (a distance from one end of the transport path is 1,
2, 3, 4, 5, 6 mm). As described in detail above, according to the present invention, the transport position of a coin to be transported is detected, and at least the output of the magnetic sensor is determined in accordance with the detected transport position of the coin. , It is possible to provide a coin identification device that enables highly accurate coin identification regardless of the coin transport position.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of an entire control circuit of a coin identification device according to one embodiment of the present invention. FIG. 2 is a plan view showing a configuration of a coin identification device. FIG. 3 is a side view showing a configuration of the coin discriminating apparatus in a partial cross section. FIG. 4 is a schematic configuration diagram of a first magnetic sensor. FIG. 5 is a schematic configuration diagram of a second magnetic sensor. FIG. 6 is a side view showing a configuration of the diameter detection sensor in a partially sectional view. FIG. 7 is a front view showing the configuration of the diameter detection sensor in a partially sectional view. FIG. 8 is a timing chart for explaining a coin transport position detecting operation. FIG. 9 is a diagram for explaining an output correction method of a second magnetic sensor. FIG. 10 is a diagram showing an example of tabulated determination reference value data according to a modification of the present invention. [Description of Signs] 1 coin, 2 transport path, 3 transport belt, 5 first magnetic sensor, 7 diameter detection sensor, 8 second magnetic sensor, 22 first magnetic sensor Primary coil, 23, 24
... secondary coil of the first magnetic sensor, 33 ... primary coil of the second magnetic sensor, 34, 37, 38 ... secondary coil of the second magnetic sensor, 42 ... light source, 44 ... line sensor, 5
5 A / D converter, 68 arithmetic circuit, 70 CPU, 7
1 RAM, 72 ROM (storage means), 73 diameter detection counter, 74 position detection counter.

Claims (1)

(57) [Claim 1] At least one or more magnetic sensors arranged along a transport path for transporting coins to be identified, and a transport direction of the coins along the transport path A line sensor disposed in parallel to the direction perpendicular to the line, and detecting a light-shielded state by the conveyed coin; The logical product of the pulse generated corresponding to one pixel of the sensor is taken, and the result is counted as an effective pulse to detect the diameter of the coin. Diameter detecting means, and the coin conveyed in the effective pixel portion of the line sensor during a predetermined time from a detection start position at which the detection operation of the line sensor is started Therefore counts the pulses generated in response to one pixel of the line sensors corresponding to the light shielding portion by the count value performs an operation of subtracting from the predetermined time, transport of the coins to be the transport Transport position detecting means for detecting the position; correcting means for correcting at least the output of the magnetic sensor in accordance with the coin transport position detected by the transport position detecting means; storage means for storing a judgment reference value in advance Determining means for determining the type of the coin by comparing the diameter of the coin detected by the diameter detecting means and the output of the magnetic sensor corrected by the correcting means with a determination reference value in the storage means; A coin identification device, comprising: