JPS5850086A - Detector for foreign matter at inlet of sheet paper handling apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a foreign object detection device for a paper input slot in a paper sheet handling device, for example, a foreign object detection device for a banknote input slot in a deposit dispensing machine.

2. Description of the Related Art In some cases, a foreign object such as a clip for bundling paper sheets, or a coin in a banknote handling device, may be accidentally inserted into a paper inlet in a paper sheet handling device along with a foreign object.

In this case, when the inserted paper sheets are taken into the apparatus, there is a risk that these foreign objects may become clogged or the conveying mechanism or other parts may be damaged. Therefore, a foreign object detection device has conventionally been provided in the paper sheet input port. Since the foreign objects that cause trouble are mainly metal, a detection coil is used as the foreign object detection device. ing. The magnetic flux generated by this detection coil l is directed in the direction in which the paper sheet is inserted. Therefore, when a metal shutter is attached to the input slot, the magnetic flux changes between when the shutter is open and when it is closed, which may cause malfunction. In addition, the magnetic flux distribution is not uniform within the recess of the input port (the magnetic flux density is significantly different between the center and the sides, so the detection signal component is small in the center where the magnetic flux density is low, and the S/N is
The ratio was so large that reliable foreign object detection could not be expected.

It is an object of the present invention to provide a foreign object detection device for inputting a paper sheet into a sheet handling device, which can always accurately detect a foreign object regardless of the presence or absence of a shutter or the position of the foreign object, and can reduce the installation space. purpose.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In Figures 1 and 2, a paper sheet input port (1) provided with a paper sheet handling device is provided with a paper sheet IP) from which the paper sheet input port (1) is inserted into the paper sheet handling device. There is a recess (2) for putting it in or storing it.

A shutter (3) is provided in the input slot (the first one) so that it can be opened and closed freely, and a paper sheet input detector (4) and a pair of foreign object detection coils (5A) (5B) are installed in the recess (2). In the back of the recess (2), there is a feeding device (6) for taking in the input paper sheet IPI into the device gate.
) are placed. In this embodiment, the injection detector (4) consists of a photoelectric detector provided so that the projected light traverses the recess (21).

A pair of detection coils (5A) (5B) are located in the recess (2)
The coils (5A)' (
5B) are wound in a plane parallel to these side walls. Therefore, the magnetic flux generated from both the detection coils (5A) (5B) is directed in a direction across the paper sheet (PJ) inserted into the recess +21 and the recess (2).

FIG. 3 shows one side of the foreign object detection circuit.

This detection circuit (indicated by αG in FIG. 4) consists of a Hartley oscillation circuit αD and a waveform shaping circuit a for its oscillation signal. The oscillation circuit αD includes a transistor (IX5) and a resonant circuit, and this resonant circuit is connected to the detection coil (5A) (5B
) and a capacitor a3. Detection coils (5A) and (5B) are connected in series.

This oscillation circuit On has a constant frequency (for example, IQ Q
It oscillates at KW z). When metal is thrown into the recess (2) together with the paper sheet IPI, the magnetic flux of the detection coils (5A) (5B) changes due to the metal, so the oscillation frequency of the oscillation circuit (111) changes.

A processing circuit, which will be described later, determines whether the change in the oscillation frequency exceeds a predetermined required value.
A foreign object detection signal is output when the required value is exceeded.

In Fig. 1, the recess (2) of the input D (11) is arranged vertically, so that the paper sheet is inputted downward.Therefore, the shutter (3) opens and the paper sheet IP+ is input. Then, the paper sheet (P) falls under its own weight, and at this time, the presence or absence of foreign matter is inspected.The recess (2) may be arranged horizontally.

In this case, when the shutter (3) is opened and the paper sheet IP) is inserted into the input slot (1), the detector (4)
detected by. When the shutter (3) is closed by this paper sheet detection signal, the paper sheet is carried into the apparatus by a carrying device (path shown) provided in the recess (2).

During this loading process, the paper sheet (Pl) is transferred to the detection coil (5
A) Since it passes through point (5B), it is inspected for the presence of foreign matter. When a foreign object is detected, sheet 5 (IP) is immediately taken out, the shutter (3) is opened, and sheet +P) is returned.

FIG. 4 shows a processing circuit for inspecting the presence or absence of foreign object detection, and FIG. 5 shows its output signal waveform.

The counter 3υ is a preset counter, which is set to a constant value in advance, and continues counting while the detection signal (Al) is output from the sheet detector (4).The output of the detection circuit u■ Pulse IB) is a counter (2+)
is being entered. The detector (4) starts counting the detections and outputs an H level signal (C1).

This signal (C1 is sent to the reset terminal of the counter Q11, the gate control circuit, and the gate circuit).

When the control circuit (to) receives the signal tc), it outputs the gate control signal p) at %H. Therefore, the gate (C) is opened and the signal C) is sent to the counter. A reference pulse (F) (for example, 4 MH!) from the reference oscillation circuit cylinder is input to the counter @, and the counter (2) counts this pulse (tF) when the signal C) is input.

When the counter (21) counts a predetermined number (for example, 100 pulses IB), the signal tel goes low.
level, and the counter Qυ is reset. This counter (2) then starts counting again from the beginning. When the signal tel goes low, the signal 10) also goes low, and the counter 2 stops counting.

Let the count of the counter (2) at this time be (CO).

This count value (CO) is stored in the counter @, and sent to the counter (c) to be preset.

After the paper sheet detection signal (Al is output), the counter (21)
Until the first counting is completed, paper leaf IP)
has not yet reached the detection range of the detection coils (5A) (5B). Therefore, the time required for the first count of the counter Ca1l (To) is 4 years old, which represents the oscillation frequency of the detection circuit that is not affected by the foreign matter contained in the paper sheet tPl. Let (T O) be the reference time.

When the counter (21) starts counting for the second time.

It(C1 becomes H level J again. Then, the gate control signal IEI is output from the gate control circuit (incorporated).

Gate ■ opens, so input signal C) to the chi counter. The reference pulse IFI is also input to the counter. The counter subtracts the count value (CO) preset by the counter (2) every pulse (Fl), and starts this subtraction operation when the signal tc is input. Since the gate (c) is closed, the counter (support)
no longer performs counting operations.

When the second and subsequent operations of the counter (21) are started, the paper sheet IP) may reach the detection range of the detection coils (5A) (5B). When a foreign object is present in the paper sheet [P], the oscillation frequency of the detection circuit αα generally becomes brighter. Therefore, the counting time of the counter 211 from the second time onwards (
Tl) (T2) etc. are shorter than the reference time (To). Therefore, the counter does not complete counting the count value (CO) within the time (TI) (T2) or the like.

The difference between the reference time (TO) and other times (Tl), (T2), etc. is shown in the output of the counter (c), and this is read into the CPU@ via the human output interface (support). The allowable range for the above difference is determined and stored in advance in the CPU.

When the output of the counter (c) exceeds this allowable range, a foreign object detection signal is output. This detection signal is sent by the transmission control circuit to 1) of a display device such as a CRT provided in the sheet handling device, and a message indicating that a foreign object has been detected is displayed.

When the paper sheet tPl passes the detector (4), a signal t
Since Al goes to L level, all the above operations stop.

The oscillation frequency of the detection circuit a changes somewhat depending on ambient conditions such as temperature. However, in the circuit shown in Figure 9J4,
Since the oscillation frequency (time (To)) of the detection circuit Uα when the paper sheet tP) is inserted is used as the reference, accurate foreign object detection is always possible regardless of changes i in the ambient conditions.

FIG. 6 shows the position (
The figure shows the change in the oscillation frequency (△f) of the detection circuit (IOl) for the detection circuit (see Figure 2). a,
This is the difference in oscillation frequency between the two cases. The graph shown by the solid line is due to the detection coils (5A) (5B) l in this invention, and the graph shown by the broken line is the change in the conventional example in which the detection coil is wound annularly around the recess (2). It shows. As is clear from this graph, in the conventional device, the variation (△f) decreases significantly at the center of the recess (2), but with the detection coil (5A) of the present invention (
According to the arrangement 5B), the variation (Δf) is almost constant regardless of the position.

In the above embodiment, the sensing coil is connected to the resonant circuit of the Hartley oscillation circuit, but it can also be connected to another oscillation circuit. In this case, the oscillation constants other than the frequency, such as voltage and current, may change due to changes in the inductance of the oscillation circuit Cj detection coil. Further, a change in the inductance of the detection coil can also be detected by a detection circuit other than the oscillation circuit.

As described in detail above, according to the present invention, a pair of detection coils are provided, and these detection filters are arranged opposite to each other with the recess in between so that the generated magnetic flux crosses the recess. There are 6 arranged. Since the direction is perpendicular to the direction, the change in the inductance of the detection coil due to foreign matter becomes large, and the SZN ratio can be reduced1, making it possible to detect foreign matter with high accuracy. Since the magnetic flux crosses the recess and the influence of the magnetic field does not extend to the vicinity of the shutter of the input port, even if a metal shutter is attached, there is no possibility that this shutter will cause false detection. Furthermore, since it is sufficient to arrange one pair of detection coils on both sides of the recess, the configuration is simple and requires only a small space.

[Brief explanation of the drawing]

A schematic cross-sectional view showing the configuration of the 124th paper sheet input port, Fig. 2 is a perspective view showing the arrangement of the detection coil d, WS3 diagram is a circuit diagram showing one example for each detection time, and Fig. 4 shows the processing circuit. Block diagram. FIG. 5 is a time chart showing each signal in the processing circuit. FIG. 6 is a graph showing the characteristics of the foreign object detection device. fil...Input port, +21...Nissin, (5~(5B
)...Detection coil, αe...Detection circuit, Ql)...
・Oscillation circuit. Patent applicant: Tateishi Electric Co., Ltd.

Claims (1)

[Claims] (1) A pair of detection coils provided with a recess in the input port,
and a detection circuit that detects a change in the inductance of these detection coils, and the pair of detection coils are arranged to face each other with a recess in between so that the generated magnetic flux crosses the recess. Inlet foreign object detection device in handling equipment. +21 A paper sheet input detector placed further than the detection coil in the recess of the input opening, and a circuit for detecting a reference value regarding the inductance of the detection coil at the time of outputting the input detection signal, and detecting this reference value. An input port foreign object detection device port in a paper sheet handling device according to claim (1), wherein a change in inductance of a detection coil is detected.