JPH0727586B2 - Banknote magnetic pattern detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a bill magnetic pattern detection device, particularly a vending machine,
The present invention relates to a magnetic pattern detection device in a bill validator such as a money changer.

[Prior Art] Conventionally, as this kind of magnetic pattern detecting device, for example, a device as shown in FIG. 7 is known.

That is, the magnetic signal detected by the magnetic head 1 is amplified by the amplifier 2, and the comparator 3 compares it with a reference value to convert an analog signal into a digital signal. 4 is a CPU, 5 is a ROM that stores control programs, etc.
Is.

The state of this digital signal conversion is shown in FIG. In FIG. 8, 6 is a bill, 7 is a magnetic pattern band, A is a detected analog magnetic signal, and B is a converted digital magnetic signal.

Therefore, the conventional detection method divides the bill into a plurality of zones, as shown in FIG. 9, and detects the magnetic pattern of the bill depending on whether a magnetic pulse signal is detected in the divided zones. It is a thing.

[Problems to be Solved by the Invention] However, although such a conventional detection method can determine the presence or absence of magnetism in a preset zone, it cannot accurately determine the width of the magnetic pattern. It had the drawback that it could not detect patterns.

In order to eliminate such defects and perform accurate pattern detection, it is conceivable to increase the number of divided zones and make fine determinations, but this requires a large amount of memory and is expensive.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional drawbacks and to provide a bill magnetic pattern detecting device capable of accurately detecting a pattern with a simple configuration without increasing the memory capacity.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention traces the surface of a bill to be conveyed and responds to its magnetic pattern, as shown in the functional block diagram of FIG. A magnetic detection sensor 27 for outputting the magnetic detection signal, a magnetic pulsing means 11 for converting the magnetic detection signal into a pulse signal, a moving pulse generating means 12 for generating a pulse according to the moving distance of the bill, and Moving pulse counting means 13 for counting the pulses generated by the moving pulse generating means 12, timer means 14 for counting the time while clearing the counted value each time the pulse signal of the magnetic pulsing means 11 is generated, and the timer means 14 The first comparison / determination means 15 for comparing and determining whether or not the time measurement value of No. has reached a predetermined value and the pulse value of the magnetic pulsing means 11 are generated, and the time measurement value before the timer means 14 is cleared. Is the first Start value storage means for storing a count value of said moving pulse counting means 13 when it is determined to reach a predetermined value by the compare decision means 15
16 and the magnetic pulse converting means when the first comparison / determination means 15 determines that the timekeeping value has reached a predetermined value, and clears when the timekeeping value has not reached the predetermined value.
Magnetic pulse counting means 17 for counting 11 pulse signals, and magnetic pulse counting means 17 each time the pulse signal of the magnetic pulse converting means 11 is counted by the magnetic pulse counting means 17
Second comparison and determination means 18 for comparing and determining whether or not the time count value of has reached a predetermined value, and the moving pulse every time the second comparison and determination means 18 determines that the count value has reached a predetermined value. The end value storage means 19 for storing the count value of the counting means 13 and the stored value of the end value storage means 19 when the first comparison / determination means 15 determines that the measured value has reached a predetermined value. It is characterized by comprising pattern width calculation means 20 for calculating the pattern width by subtracting the stored value of the start value storage means 16.

[Operation] In the present invention, the magnetic detection signal detected by the magnetic detection sensor 27 is converted into a pulse signal by the magnetic pulsing means 11.

Since the timer means 14 keeps the time value while clearing the time value each time this pulse signal is generated, the time value indicates the pulse interval of the pulse signal. The first comparison / determination means 15 is for determining whether the pattern is a continuous pattern or a discontinuous pattern by comparing the measured value with a predetermined value. When the measured value does not reach the predetermined value, the pulse signal Is a continuous pattern at intervals shorter than a predetermined value, so that the pattern is continuous, and when the measured value reaches a predetermined value, the pulse interval of the pulse signal is equal to or larger than the predetermined value, and thus the pattern is discontinuous.

Since the moving pulse counting means 13 counts the pulses according to the moving distance of the bill, the count value indicates the position of the bill with respect to the magnetic detection sensor 27. The start value storage means 16 counts moving pulses when it is determined that the timed value of the timer means 14 has reached a predetermined value, that is, when the pulse signal of the magnetic pulsing means 11 is generated in a discontinuous pattern state. Since the count value of the means 13 is stored, the pulse signal is the first pulse, and the count value of the moving pulse counting means 13 stored at that time indicates the start position of the continuous pattern.

The magnetic pulse counting means 17 is cleared when it is determined that the timed value has reached a predetermined value, that is, when it is in the discontinuous pattern state, and when it is determined that the timed value has not reached the predetermined value, that is, the continuous pattern state. At this time, since the pulse signal of the magnetic pulsing means 11 is counted, the count value indicates the number of pulses of the continuous pattern.

The second comparison / determination means 18 is for removing the influence of noise mixed in the magnetic detection signal by comparing the count value with a predetermined value. When the count value does not reach the predetermined value, As will be described below, the end value storage means 19 does not store the count value, and when the count value which does not reach the predetermined value is counted and the discontinuous pattern state is reached, the count value is counted by the magnetic pulse counting means 17 described above. Is cleared, so generation of such a pulse is ignored so that it is not affected by noise.

The end value storage means 19 is the magnetic pulsing means 11 each time the second comparison / determination means 18 determines that the count value has reached the predetermined value, that is, in the state where the pulse number of the continuous pattern has reached the predetermined value. Each time a pulse signal of is generated, the count value of the moving pulse counting means 13 is stored, and the stored value is updated every time the pulse signal of the magnetic pulsing means 11 is generated, and in that state, When the comparison and determination unit 15 of No. 1 determines that the timekeeping value has reached the predetermined value, that is, the stored value when it is determined to be the discontinuous pattern indicates the end position of the continuous pattern.

The pattern width calculation means 20 uses the stored value of the end value storage means 19 indicating the end position to indicate the start value storage means 16 indicating the start position.
Is subtracted from the stored value, and the subtracted value indicates the width of the continuous pattern.

[Embodiment] An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 2 shows an example of a bill validator to which the present invention is applied. 21 is a drive motor, 22 is a gear box for reducing the rotation of the drive motor 21, and 23 is the number of rotations of the drive motor 21. A tacho generator 24 is a bill transport belt provided on both sides of the bill transport path 26, and is driven by rotating a roller (not shown) or the like with a drive shaft 25 which is an output shaft of the gear box 22.

The signal from the tacho generator 23 is sent to the microcomputer 30.
Entered in. Further, 27 is a magnetic detection sensor, and 28 is an A / D converter for obtaining a digitized magnetic signal.

The signal from the tacho generator 23 is output as shown in FIG. 3, for example, according to the rotation speed of the drive motor 21, that is, the moving distance of the bill. Therefore, the moving distance of the bill can be measured by counting the number of the pulses. For example, when the rotation speed of the drive motor 21, the reduction ratio of the gear box 22, the rotation speed of the rollers, etc. are adjusted so that the tacho generator 23 outputs one pulse when the conveyor belt 24 moves by 1 mm, If you counted 10 pulses,
This means that it has moved 10 mm. As the bill moves, the magnetic detection sensor 27 detects the magnetic state, and the A / D converter 2
The digital magnetic signal is input to the microcomputer 30 via 8. An example of this digital magnetic signal is shown in FIG.

Next, an example of setting the determination value T _S used for determining whether the magnetic pattern is a continuous pattern or a discontinuous pattern will be described with reference to FIG.

In the magnetic pulse detection waveform of a bill, if the section of several pulses that occur continuously is L, the maximum pulse interval time in this section L is T _1, and the discontinuous pulse interval time is T ₂ . Then, the predetermined value T _S is set as a value larger than T _{1 and} smaller than T ₂ .

An example of the control procedure of this embodiment will be described with reference to the flowchart shown in FIG.

A bill is inserted, the drive motor 21 starts rotating, and at the same time, bill feeding by the transport belt 24 is started (third part).
(Point A in the figure) and the control of the main routine [I] for pattern width measurement is started, the interval timer is started in step S1, the start memory value is cleared at the same time, and the count value of the tacho generator 23 is cleared. .

Next, in step S2, a pattern width detection flag described later is set, and at the same time, the end memory value is cleared.

Whether or not the pattern width detection flag is set is determined in step S3, and a closed loop is formed as long as it is set. On the other hand, every time the pulse signal of the tacho generator 23 is input during this period, it is processed as an interrupt input, and the count value of the tacho generator 23 is incremented by one in the subroutine [III] of FIG.

The above-mentioned pattern width measurement was started from the point A, but since the magnetic pulse signal is not detected until the point B, the main routine constitutes a closed loop and is in a standby state.

However, when a digital magnetic signal is generated at the point B, the magnetic interrupt subroutine processing of FIG. 5 [II] is performed. First, at step S11, the registers are saved,
In step S12, it is determined whether the value of the interval timer started in step S1 of the main routine is larger or smaller than the predetermined value T _S. In this example, since it is larger than the predetermined value T _S , the process proceeds to the route, and the magnetic interrupt count value described later is cleared in step S13, and at the same time, the set of the pattern width detection flag is cleared. Then, in step S17, the value of the interval timer is cleared and restarted.

When the pattern width detection flag is cleared in the magnetic interrupt subroutine (step S13), the main routine proceeds to step S4, and the start memory value is subtracted from the end memory value. In this case, the end memory value is "00", and since the start memory value is "00", the subtraction cannot be performed and the value becomes "00", which means that there is no magnetic pattern. The result is stored in the pattern width memory. At the same time, the current tacho generator count value (“08” in this example) is stored in the start memory.

Next, proceeding to step S5, it is determined whether or not the pattern width measurement is completed, but as long as the bill is present in the transport path,
Since it does not end, the process returns to step S2 to set the pattern width detection flag, clear the end memory, and wait for the next magnetic interrupt.

When a magnetic interruption occurs thereafter (occurs at the pulse next to point B), since it is smaller than the predetermined value T _S this time, the process proceeds to the route, and one magnetic interruption count value is added in step S14. In step S15, it is determined whether or not this count value is larger than 3, but in this example, since it is still smaller than 3, the process proceeds to step S17 to clear the value of the interval timer and restart it.

In this way, if the magnetic interrupt continues, the value of the magnetic counter becomes 3. Therefore, the process proceeds to step S16 and the tacho generator 2
Store the count value of 3 in the end memory.

That is, when the value of the interval timer is smaller than the predetermined value T _S ,
When magnetic interrupts occur continuously, the value of the end memory is updated with the latest count value of the tacho generator 23 for every three interrupts.

In this example, the magnetic interrupt at the point C causes the end memory to store the value "17" as the count value of the tacho generator 23 as an updated value.

When a magnetic interrupt having an interval timer value larger than the predetermined value T _S occurs thereafter at point D, the pattern width detection flag is cleared in step S13 as described above, and therefore the process of step S4 of the main routine is performed. As a result of subtracting the start memory value "08" from the end memory value "17", "09" is obtained and stored in the pattern width memory shown in FIG.

As an example, if the 1 count value of the tacho generator 23 is adjusted so as to correspond to the 1 mm movement of the bill as described above, in this example, there is a magnetic pattern of 9 mm continuously from the point B to the point C. Can be detected.

It should be noted that the detection operation is similarly performed after the point D, and the width of the pattern is sequentially stored in the adjacent pattern width memory shown in FIG.

Although not described in detail, these pattern widths are compared with a reference pattern of a bill to check its authenticity.

Further, in the present embodiment, the magnetic interrupt counter is used to determine that the magnetic pattern is present only after three or more magnetic interrupts are continuously generated. Therefore, for example, a noise signal due to a disturbance is applied to the magnetic pulse signal, This is practical because it is possible to eliminate the inconvenience of accidentally updating the contents of the end memory.

[Advantages of the Invention] According to the present invention as described above, in particular, since the generation of pulses of a magnetic detection signal that does not reach a predetermined number is ignored so as not to be affected by noise, weak magnetic detection is performed. The width of the magnetic pattern can be detected more accurately from the signal.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing the configuration of the present invention, FIG. 2 is a conceptual diagram showing an embodiment of the present invention, and FIG. 3 is a magnetic pulse signal and tacho-generator output of an embodiment of the present invention. 4 is an explanatory diagram for setting the predetermined value T _S , FIG. 5 is a flowchart showing an example of the control procedure of the embodiment, and FIG. 6 is an explanation of the allocation of the used memory of the embodiment. FIG. 7 is a block diagram showing a conventional device, FIG. 8 is a diagram for explaining how a magnetic signal of the conventional device is pulsed, and FIG. 9 is a pattern detection by a zone division method in the conventional device. It is a figure explaining a situation. 11 ... Magnetic pulse forming means, 12 ... Moving pulse generating means, 13 ...
Moving pulse counting means, 14 ... Timer means, 15 ... First comparison and determination means, 16 ... Start value storage means, 17 ... Magnetic pulse counting means, 18 ... Second comparison and determination means, 19 ... End value storage means, 20
... Pattern width calculation means, 27 ... Magnetic detection sensor.

Claims (1)

[Claims] 1. A magnetic detection sensor that traces the surface of a banknote being conveyed and outputs a magnetic detection signal corresponding to the magnetic pattern, and a magnetic pulsing unit that converts the magnetic detection signal into a pulse signal. Moving pulse generating means for generating a pulse according to the moving distance of the bill, moving pulse counting means for counting the pulses generated by the moving pulse generating means, and a timed value every time a pulse signal of the magnetic pulsing means is generated. And a first comparison and determination means for comparing and determining whether or not the timed value of the timer means reaches a predetermined value, and a pulse signal of the magnetic pulsing means is generated. Start value storing means for storing the count value of the moving pulse counting means when it is determined by the first comparison / determination means that the time value before the timer means is cleared has reached a predetermined value. It is cleared when the first comparison / determination means determines that the timed value has reached a predetermined value, and the pulse signal of the magnetic pulsing means is counted when it is determined that the timed value has not reached the predetermined value. A second determination is made by comparing the magnetic pulse counting means with the magnetic pulse counting means each time the pulse signal of the magnetic pulse converting means is counted, whether or not the count value of the magnetic pulse counting means has reached a predetermined value. The comparison and determination means, the end value storage means for storing the count value of the moving pulse counting means each time the second comparison and determination means determines that the count value has reached a predetermined value, and the first comparison and determination means. Pattern width calculation means for calculating the pattern width by subtracting the stored value of the start value storage means from the stored value of the end value storage means when it is determined by the means that the timed value has reached a predetermined value. Characterized by The magnetic pattern detection device of the bill to be.