JPH01181650A - Falling coin sensing mechanism - Google Patents

Abstract

PURPOSE:To sense any fallen coin easily by laying a metal wire at a medium inlet to a terminal unit of printer etc., in such a way as facing with a distance approx. one third of the coin, and by sensing the difference in the electrostatic capacitance generated at the ends of this metal wire. CONSTITUTION:An electrode consisting of metal wires 1, 1' and 2, 2' is laid in the neighborhood of the inlet 4 to a medium insert table 3 of a terminalunit of printer etc., in such a way as facing with a distance approx. one third of coin 6. When any coin 6 drops by mistake, it shortcircuits the electrode wires to cause variation of the electrostatic capacitance at the two ends of the electrode wires. The rectangular wave generated by a pulse generator 8 varies with capacitance variation between the electrodes 1, 1' and 2, 2' to become waveform 7, and this is amplified 9 and compared with the output waveform of a reference voltage generator 11. This permits sure sensing of mixed up coins by the use of simple equipment to lead to prevention of jamming and malfunction.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a falling coin detection mechanism provided in a terminal device such as a bank teller, and in particular, to a mechanism for detecting fallen coins installed in a terminal device such as a bank teller, and in particular, for processing by inserting and removing a medium such as a printer or an image scanner. This invention relates to a falling coin detection mechanism for a terminal device such as a bank teller, which takes measures to prevent coins from entering the device and issues an alarm when coins do.

(Prior Art) Among bank teller devices, especially processing devices such as printers and image scanners, coins may get inside when a user is using the device, and if a coin falls, it may There have been requests to make the insertion slot transparent so that the coins can be seen, or to prevent them from getting inside.

However, it is difficult to make the vicinity of the entrance of the device transparent, and it is also difficult to solve the problem mechanically, such as by changing the shape.

Conventionally, as a solution to this problem, for example, in the processing apparatus described in Japanese Utility Model Application Laid-Open No. 61-84975, a step in the insertion opening prevents foreign objects such as clips from getting mixed in.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, for small items such as clips and pins, a step is provided on the bottom surface with a gap between them.
Although it is possible to drop foreign objects that have entered through the stepped gap, no consideration has been given to relatively large foreign objects such as coins. Therefore, if a coin or the like enters the processing device, the operator inserts the medium without noticing the existence of the coin, etc., and the coin or the like goes inside, and this cannot be prevented. .

On the other hand, as mentioned above, it is technically difficult to make the vicinity of the entrance of the processing device transparent or to devise a mechanical mechanism to prevent coins and the like from entering.

Therefore, it is possible to electrically detect foreign objects that have entered the
A method to prevent problems is desired.

The purpose of the present invention is to solve these conventional problems and provide a falling coin detection mechanism that can prevent troubles caused by coins, etc., from getting mixed in, without changing the shape of the insertion slot, and at low cost. It's about doing.

[Means to solve the problem]

In order to achieve the above object, the falling coin detection mechanism of the present invention is arranged at a bank teller or the like, and in a terminal device such as a printer equipped with a medium insertion slot, a drop coin detection mechanism of the present invention is installed in a terminal device such as a printer having a medium insertion slot. In addition to laying metal wires facing each other at a distance of about 100 yen, a circuit is installed to detect the difference in capacitance between the two poles of the metal wire depending on the presence or absence of a coin. The presence of the coin in the insertion slot is detected by either detecting the level of the returned waveform, or by detecting fluctuations in the vibration frequency due to the capacitance and the coil connected to the capacitance. It is characterized by reporting things.

(Function) In the present invention, the table surface of the medium insertion port of the terminal device is made of a non-metallic material such as plastic, and opposing electrodes are laid on the top surface using metal wires or conductive coating, and then a thin Abrasion is prevented by covering it with a plastic material.Then, by applying an electric charge between these electrodes, the capacitance that changes when an inserted coin crosses between these electrodes is detected, or by A circuit is provided that detects the oscillation frequency that changes due to the capacitance that changes when an inserted coin crosses between these electrodes.

When there are no coins, the electrodes laid out on the table surface of the insertion slot have an extremely small area and a long distance between them, so the capacitance is extremely small. For example, the area of the electrode is determined by (cross-sectional area of the wire) x (length), and the distance is 6 to 7 mm (approximately 173 mm of the coin diameter).

When a coin is placed on these opposing electrodes, the distance between the coin and the electrode is 0.5 to 1.0 mm, and the length is 10 mm.
Since the capacitance becomes close to each other, the capacitance increases greatly. By detecting this increased capacitance with a detection circuit, the presence of a coin is known.

Note that the circuit that detects the capacitance between the electrodes has a sufficient SN
Since the ratio is maintained, there will be no malfunction due to the coin coming close to the electrode.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view of a terminal device insertion slot showing an embodiment of the present invention, and FIG. 2 is a side view of the terminal device insertion port when cut horizontally along an arbitrary line in FIG.

In FIGS. 1 and 2, reference numeral 3 denotes a table on which paper is set on the front side of the apparatus, and a table 4 near the entrance of the apparatus includes:
A total of four opposing electrode wires 1 and 2 and electrode wires 1' and 2' are buried. Electrode lines 1 and 1' have the same polarity, electrode lines 2 and 2' have the same polarity, and a constant charge is applied to these four electrodes. 5 is a conveyance roller that feeds the set paper into the apparatus. Note that the mechanism inside the device is not shown in the drawings.

FIG. 3 is a block diagram of a falling coin detection mechanism showing an embodiment of the present invention, and FIGS. 4 and 5 are a waveform diagram and an equivalent circuit diagram, respectively, for explaining the operation of FIG. 3. .

The configuration of the detection circuit and its operating principle when the coin 6 falls onto the electrode of the insertion slot in FIGS. 1 and 2 will be explained. Of course, this operating principle remains the same even if the coin 6 moves.

In Figure 3, 1, 2.1', 2 are electrodes, 6 is a dropped coin, 8 is a pulse generator that generates a rectangular wave pulse, 7 is an output waveform from the pulse generator 8, and 9 is an output waveform 10 is a comparison/judgment device for comparing the output waveform voltage of the pulse generator 8 and the reference voltage. 11 is a threshold value that is large enough to detect the presence of a coin by comparing the returned waveform. It is a reference voltage generator that generates voltage.

First, the pulse generator 8 generates a signal between the electrodes 1 and 2.

A charge is applied between 1' and 2' at fixed time intervals.

The waveform shown in FIG. 4(b) is the pulse waveform generated by the pulse generator 8, and the waveform shown in FIG. 4(a) is the output waveform returned from the electrode 1-2.1'-2'. be.

One of the rectangular waveforms generated by the pulse generator 8 (the waveform in FIG. 4(b)) is applied to the electrode 1-1. and 1' - 2', the electrode emits a
) will return the waveform shown. This waveform is amplified by an amplifier 9 and output to a comparison/judgment unit 10.

The comparison/judgment device 10 compares the input waveform level with the reference voltage level generated by the reference voltage generator 11, and detects a falling coin when the input waveform level becomes smaller than the reference voltage level.

When the coin falls, the capacitance between electrodes 1-2 and 1'-2' increases, so the output level decreases. That is, as shown in FIG. 4(a), the voltage 7 returned by the pulse application changes depending on the capacitance between the electrodes, and the output waveform 7 changes from above the level of the broken line of the reference voltage to below the level of the broken line. The point at which the coin falls is the point at which the coin falls. If the distance between the electrodes is set to about 175 to 173 of the coin diameter, the capacitance will change depending on when there is no coin between the electrodes and when there is a coin between the electrodes. In other words, as shown in FIG. 5(,), when there is no coin between electrodes 1 and 2, it is equivalent to the case where one capacitor is connected between electrodes 1 and 2, but as shown in FIG. (b
), when a coin falls between electrodes 1 and 2,
This is equivalent to connecting a separate capacitor in parallel with the originally existing capacitor between electrodes 1 and 2.
-2 capacitance increases.

Therefore, by determining the output pulse and the comparison voltage for the applied pulse and comparing them, it is possible to reliably determine whether the coin has fallen.

Note that the optimum value of the threshold value of the reference voltage is determined through trial production, experimentation, and the like.

When a coin is detected, a lamp or buzzer will notify the operator of the abnormality and stop the suction.
Contamination into the equipment can be prevented. In addition, in order to stop the suction, it is sufficient to stop the rotation of the roller 5, and the electrode 1-
2.1'-2' may be exposed on the table surface, but it is desirable to coat it with a thin layer of wear-resistant material to prevent wear.

Further, the electrode thickness, pitch, coating thickness, applied voltage, amplifier amplification factor, determination reference voltage, etc. may be selected at optimal values depending on the mechanism and circuit configuration.

FIG. 6 is a circuit diagram of a main part of a falling coin detection mechanism showing another embodiment of the present invention.

Another method for detecting a fallen coin is to configure an LC oscillation circuit 12 using the capacitance C0 between electrodes 1 and 2 and the inductance of a separate coil L0, as shown in FIG. A method of detecting a change in natural frequency due to a change in capacitance between the two can be used. A frequency fluctuation detection circuit 13 is connected to the output side. This circuit 13 is
This can be realized using a circuit configuration that is often used in radios, rulers, etc.

When a coin falls, the capacitance C becomes larger than the normal value, and the vibration frequency becomes smaller than the value 1/γr, so this change in frequency is detected by the frequency fluctuation detection circuit 13.
Detect with.

〔Effect of the invention〕

As explained above, according to the present invention, a method for reliably detecting coins can be realized at low cost without changing the shape of the media insertion slot of the device, thereby preventing the occurrence of paper jams and deterioration of operability. Troubles caused by coins being mixed in can be prevented without causing problems.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a device insertion port showing an embodiment of the present invention;
2 is a side sectional view of FIG. 1, FIG. 3 is a block diagram of the coin detection circuit of the present invention, FIG. 4 is a diagram of the output waveform and pulse generation waveform of FIG. 3, and FIG. 5 is a diagram of the coin detection circuit of the present invention. FIG. 6 is an equivalent circuit diagram for explaining the operation of the figure, and FIG. 6 is a configuration diagram of a coin detection circuit showing another embodiment of the present invention. 1.2,1', 2': Electrode, 3: Insertion rotary pull, 4: Entrance of device, 5: Paper transport roller, 6: Coin,
7: Output waveform, 8: Pulse generator, 9: Amplifier, 10:
Comparison/judgment device, 11: Reference voltage generator, 12: LC oscillation circuit, 13: Frequency fluctuation detection circuit. Figure 1 Figure 2
Fig. 6] Fig. 4 When the coin is falling Fig. 5 (a) Normal (b) When the coin is falling Fig. 6 Applied voltage

Claims (1)

[Claims] 1. In a terminal device such as a printer located at a bank counter etc. and equipped with a media insertion slot, metal wires are laid facing each other at a distance of about 1/3 of the diameter of a coin in the media insertion slot. In addition, a circuit is provided to detect the difference in capacitance between the two poles of the metal wire depending on the presence or absence of a coin, and the detection circuit detects the level of the return waveform of the pulse applied to the electrode, or A fallen coin detection system, characterized in that the presence of a coin in the insertion slot is detected by detecting fluctuations in vibration frequency caused by a capacitance and a coil connected to the capacitance, or by either one of them, and the detection is reported. mechanism.