JPS58137090A - Pattern reader for sheet papers - 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 pattern reading device for paper sheets such as banknotes.

In general, automatic machines that accept banknotes, such as automatic teller machines and automatic teller machines, read the patterns consisting of letters and patterns on the banknote surface during the process of receiving and conveying banknotes to determine the authenticity of the banknote. The denomination is being determined. Conventionally, banknote pattern discrimination in this type of automatic equipment involves reading the banknote pattern using one or two sensors fixed on the conveyance path while transporting the banknote in the short side direction, and comparing it with a standard pattern stored in advance. This was done by doing this. However, with this method, if the central axis of the conveyor belt and the central axis of the banknote are misaligned, an unusual track pattern may be read, resulting in misjudgment.

Therefore, the inventors of the present application have already proposed a number of improved paper sheet pattern reading devices in order to overcome the drawbacks of the conventional devices.

One of them is, as shown in FIG. 1, two sensor arrays 1 and 2, such as image sensors each having a plurality of bit sensors connected in series, are connected to a transport path 5 consisting of transport healds 3 and 4.
These sensor rows 1 and 2 are arranged on both sides of the transport path 5 to intersect with the transport direction By the way.

First, both ends 7 and 8 of the banknote 6 are detected, and then the signals from the sensor units 1b and 2b located a certain distance away from the sensor units 1a and 2a that detected the ends are sampled and output. Track 9 at a certain distance from 8
・It reads 10.

This device eliminates the misjudgment caused by the deviation of the center axis of nine banknotes, but it requires two sensor rows.
In order to reduce the number of required sensor rows to one, the length of sensor row 1 is extended to the outer end of sensor row 2, and the sensor row 1 is operated from the bottom to the top. Since the position of the upper track 10 is not known until the upper edge 8 of the second bill B is detected, the analog outputs of all sensor units within the possible range of the track 1i]j are memorized. Therefore, the memory element capacity must be increased, and it is not practical to make the sensor data 11 rigid. In any case, the device shown in FIG. 1 is expensive.

Next, a pattern reading device shown in FIG. 2 was proposed to eliminate the drawbacks of the device shown in FIG. 1. This device transports the banknotes 6 in the X direction, and a light source 11 that is arranged in the Y direction intersecting the transport direction and illuminates a range of banknotes including one end 7 and one track 9 of the banknotes 6, and A range of banknotes including the end 8 and the other track 1o: A light source 12 that illuminates the river is provided, and reflecting mirrors 13, 15, 14, and 14 reflect the light beams from these light sources 11 and 12 that are transmitted through the banknote 6, respectively. 16 and converges on a sensor 18 through a lens 17. The light sources 11 and 12 are turned on alternately, and the sensor array 18 is scanned in synchronization with the alternate lighting. Therefore, the range including one end 7 and track 9 of 9 banknotes and one end 8
Since the range including the tracks 10 and 10 is scanned alternately from both ends of the banknote toward the center, one sensor array scans two axially symmetrical areas at a certain distance from both ends of the banknote. Tracks can be read. However, this device requires two light sources, and furthermore, it is necessary to turn on the two light sources alternately and scan the sensor array in synchronization with this alternate lighting, making the control complicated. .

The purpose of the present invention is to eliminate the drawbacks of the conventional device and the device related to the prior application described above at once, and to produce a paper sheet system that does not cause error discrimination even if the center of paper sheets such as banknotes is deviated, and that is easy to control. To provide a pattern reading device.

In order to achieve the above object, the paper sheet pattern reading device of the present invention has nine single light sources capable of irradiating the width of the paper sheet in a direction intersecting the conveying direction of the paper sheet.

The light emitted from this light source and transmitted or reflected in a predetermined range in a direction transverse to the conveyance direction, including one end of one edge of the paper sheet parallel to the conveyance direction, is transmitted to one side of the divided sensor array. a first group of mirrors that converges light on the sheet, and light irradiated by the light source and transmitted or reflected in a predetermined range in a direction intersecting the conveyance direction, including one end of the other edge of the paper sheet parallel to the conveyance direction. It is characterized by a second group of mirrors that converge light on the other side of the divided sensor row, and the two tracks are axially symmetrical at a predetermined distance from both ends parallel to the conveying direction of the two paper sheets. The pattern is read on one side and the other side where the sensor row is divided.

The present invention will be described in detail below with reference to embodiments shown in the drawings. In the drawings, the same numbers as those in the apparatus shown in FIGS. 1 and 2 indicate the same or corresponding parts.

FIG. 6 is a configuration diagram showing the main parts of a banknote pattern reading device showing an embodiment of the present invention, and FIG. 5 (5) is a plan view thereof, and FIG. 6 CB) is a side view thereof. In the figure, the light source 11 is disposed below a conveyance path (not shown) consisting of a conveyance belt, and its length extends below the entire width of the banknote 6 from one end 7 to the other end 8 of the banknote 6 conveyed on the conveyance path. It is long enough that it can be irradiated from The mirrors 13 and 14 are respectively arranged above a range including one end 7 and the track 9 of the banknote O and a range including the other end 8 and the track 10, and are arranged parallel to the X axis and inward with respect to the XY plane (conveyance plane). It is placed at a certain angle. Mirrors 15 and 16 are located between mirrors 13 and 14, parallel to the Z axis (an axis perpendicular to the transport surface) and parallel to the X axis.
They are arranged in a V-shape, tilted 45 degrees outward from the axis. The lens 17 is provided in front of the mirrors 15 and 16 in the X direction, and further in front of the lens 17 in the X direction is an image sensor 18. Note that the mirrors 13 and 14 are arranged so that the light beam from the mirror 13 is focused on the first half scanning section 18a of the image sensor 18.

The inclination angle and position are set so that the light beam from the mirror 14 is focused on the second half scanning section 18b of the image sensor 18.

With the above structure, when the bill 6 is irradiated with the light beam from the light source 11, the Y-direction image of the range including the one end 7 and the track 9 of the bill 6 is converted into two-direction images by the mirror 1. , and is further projected by the mirror 15 and lens 17 onto the front half scanning section 18a of the image sensor 18 as images in two directions. Similarly, an image in the -Y direction of a range including one end 8 of the banknote 6 and the track 10 is also converted into an image in the Z direction by the mirror 14.

The image is projected onto the second half scanning section 18b of the image sensor 18 by the Sarani mirror 16 and lens 17 as images in two directions. In this case, the directions of the image near one end 7 and the image near the other end 8 of the banknote 6 are Y and -Y and are opposite, but mirror 13 and mirror 1
4 are opposite to each other, the directions of the images formed on the image sensor 18 are the same. Therefore, when the image sensor 18 scans from the bottom to the top, that is, from the first half scanning section 18a to the second half scanning section 18b, the first half scanning section 18a scans the bill 6 from one end 7 toward the center, and the second half scanning section iBb scans the bill 6. It will be scanned from the other end 8 toward the center.

FIG. 4 is a block diagram showing an example of the electric circuit of the device shown in FIG. A counter receives a reading command signal input from a banknote detection sensor (not shown) and generates a start signal, 23 is an amplifier that receives and amplifies the output signal of the image sensor, and 24 is a reference voltage level/L/V. a comparator 25 for comparing the output of the amplifier 23, ie the read signal e;
is a change detection circuit that detects level changes in the read signal.

26 is a delay circuit for delaying the change detection pulse 11 from the change detection circuit 25 for a certain period of time, and 27 is a sample hold circuit that samples and holds the read signal C from the amplifier 2 when it receives the output pulse i from the delay circuit 2B. , 28 is A for converting the output of the sample and hold circuit 27 into a digital value.
-D converter 29 is a memory that stores the digital signal from the A-D converter 28. Note that 18 is an image sensor corresponding to that shown in FIG.

The image sensor 1B stores a charge corresponding to the amount of incident light in each sensor unit, and in synchronization with the clock (ij number a), the analog level taken in during the previous scan, which is proportional to the amount of charge accumulation, is bit-serial, that is, clocked. Output sequentially.

The change detection circuit 25 detects the edge 7 (8) of the banknote B, and as shown in FIG.
5"1, 252, an EXOR gate 25, an inverter 254, and an AND gate 255. In this change detection circuit 25.

The output signal d of the comparator 24 is input to the D terminal of the D-type flip-flop 251, and when the clock signal a is applied to the T-terminal of the D-type flip-flop 251, the output signal d is stored. Furthermore, the output signal e of the D-type flip-flop 251 is applied to the D terminal of the D-type flip-flop 252,
The D-type flip-flop 252 stores the output signal e according to the next clock signal a. EXOR gate 253
The output signal C of the D-type flip-flop 251 and the output signal of the D-type flip-flop 252 are added to the input terminal,
The exclusive OR is taken and the gate output number g is output. The AND gate 255 receives the output signal e of the D-type flip-flop 251 at its input.

The gate output signal g and the clock signal a which is inverted by the inverter 254 are added and their logical product is taken.

A change detection signal is output.

The delay circuit 26 delays the change detection signal 11 of the change detection circuit 25 by a predetermined period of time, and includes an inverter 261 and a preset counter 262 as shown in FIG. In this delay circuit 26, the preset counter 262 has the ends 7 and 8 of the banknote 6 and the predetermined track 9.
A value corresponding to a distance of 10 is preset. When a detection signal indicating detection of the edges 7 and 8 of the banknote 6 is applied from the change detection circuit 25, counting is performed in synchronization with the clock signal a, and when the preset value is reached, an output signal i is output. That is, this delay circuit 26
8 is detected until the unit sensors located on tracks 9 and 10 are scanned. The delayed output signal i is composed of a sample hold circuit 27, an A-D converter 28, and a near-analog switch 271, a capacitor 272, and an Ohe7''275 as shown in FIG. In this sample hold circuit 27, the analog switch 271 is controlled by the delayed output signal i.The read signal C is added as an input signal, and the read signal C, that is, the track 9 Alternatively, the level signal at the 1o position is applied to the capacitor 272 and held.

This hold signal is derived via an operational amplifier 273 as an analog hold output signal j. The level of the analog hold output signal J is held until the next delayed output signal i, that is, the sampling signal l is applied.

Next, the operation of the embodiment shown in FIGS. 6 and 7 will be explained with reference to the signal waveforms of each part shown in FIG.

When the banknote 6 is conveyed along the conveyance path and the front edge of one banknote 6 reaches the vicinity of the light source 11, the banknote 6 is detected by a banknote detection sensor (not shown).
is detected, and a reading command signal is applied to the counter 22 from this banknote detection sensor. When the counter 22 receives the reading command signal, it outputs a start signal S in synchronization with the clock signal a. This start signal is a pulse signal that is issued once per scan. When this start signal is applied to the image sensor 18, it starts scanning from the bottom to the top in FIG. 5(B) based on the clock signal a.

On the other hand, part of the light from the light source 11 passes through the banknote 6, and the other part is directly reflected by the mirrors 13, 14 and 15, 16, and is focused by the lens 17 to form an image on the image sensor 18.

Therefore, when the image sensor 18 is scanned from the bottom to the top as shown in Figure 3, the light source 11 and the banknote 6 are first detected as shown in Figure 6 CB
) is scanned from the left end 7 toward the center. Therefore, the image sensor 18 does not scan direct light for several bits at the start of scanning without passing through the bill 6, and its read output signal C also derives a partial level output exceeding the reference level /I/v.

Therefore, the output signal d of the comparator 24 is also at L level, and the D-type flip-flop 251 of the change detection circuit 25
The output signal e of is also at L level.

In addition, in FIG. 8, sl・s2...55 of the output signal e
12... Indicates the level of each bit of the image sensor 18 synchronized with the clock signal a, and in the embodiment, it is 102.
In the case of a 4-bit image sensor, 'k' is shown.

As the scanning progresses and the banknote A reaches one end 7, the banknote 2 receives the light that has passed through the banknote 6, so the reading signal e becomes smaller than the reference level /L/v due to the printing pattern of the banknote 6.

Therefore, the output signal of the comparator 24 becomes H level, and in response to this, the output signal e of the D-type flip-flop 251 also becomes H level (at time t1 in FIG. 8). Output signal f of flip-flop 252
Also the next clock (Lao added timing TeHV
F) becomes Ly (also at time 2 in Figure 8). As a result, EXO
The output signal g of the R game) 253 goes high at t for a period of t2.
<A/. Since the output signal e of the D-type flip-flop 251, the output signal g of the EXOR gate 253, and the inverted signal of the clock signal a are applied to the AND gate 255, one space of the clock signal a during the period when the output signal g is at the H level. The output signal 11, which is at H level only during this period, is delivered to the output of the AND gate 255. This output signal is a change detection signal indicating that one end of the banknote B has been detected.

When this change detection signal 11 is applied to the preset counter 262, the preset counter 262 starts counting based on the clock signal a, and when the count increases as the scan progresses, it outputs the delayed output signal i (t3 in FIG. 8).
time). The timing at which this delayed output signal i is output corresponds to the timing at which the image sensor 18 scans the track 9 position of the banknote 6. When this delayed output signal l is applied to the sample and hold circuit 27, the sample and hold circuit 27 holds the read signal level (v) at that time and outputs an analog sample and hold output signal J.

This output signal j is digitally converted by an A-D converter 28 and stored in a memory 29 as a pattern level signal of track 9 of nine banknotes 6.

The scanning further progresses, and the first half scanning section 1 of the image sensor 18
8a and enters the second half scanning section 18b.

As the image sensor 18 scans from the bottom to the top, the light source 115 scans the bill B from the right end 8 of FIG. 3 CB) toward the center. Therefore, the scanning of the image sensor 18 is performed from the first half scanning section 18a to the second half scanning section 18.
Moving to step b, the bill surface was scanned from the left side to the right side near the center of the bill 6, but now it is scanned from the right outside of the bill 6 toward the center, so the second half scanning section 18
The scanning of the first few bits of b receives direct light and the read signal C
The level also exceeds the reference level (vV). As a result, the output signal d of the comparator 24 also goes to the L level, and the output signal e of the D-type flip-flop 251 also goes to the L-level (at time t4 in FIG. 8). The output signal f also becomes L level (at time t5 in FIG. 8). The output signal g of the EXOR 253 is at H level during the period from t4 to t5. However, in this case, since the output signal e of the D-type flip-flop circuit 251 is at the L level, no change detection signal is derived from the output terminal of the AND gate 255.

The scanning of the second half scanning section 18b of the image sensor 18 progresses and 9
When the other end 8 of the banknote 6 is reached, the light transmitted through the banknote 6 will be received, so the reading signal C will be generated depending on the printing pattern of the banknote 6.
is also smaller than the reference level/l/V. Therefore, the output of the comparator 24 is at H level.
1's output signal e also becomes H level (at time t6 in FIG. 8)
. Therefore, at time t7, AN is operated in the same way as at time t2.
A displacement detection signal is output from the D gate 255. Then, at time t8 after the delay time set by the preset counter 262, a delayed output signal l is output from the delay circuit 26, and this delayed output signal i causes the reading signal level of the track 10 position of the banknote O to be adjusted to the sample hold circuit 26.
It is held at 7.

The output signal j of the sample and hold circuit 27 is also converted into digital data by the A-reconverter 28 and stored in the memory 29.

This completes one scan, but this operation is repeated until the bill 6 passes.

Although the above embodiments have been described with reference to the case of reading patterns on banknotes, the present invention is not limited thereto, and it goes without saying that the present invention can also be applied to cases where patterns on checks, cards, and other paper sheets are read.

Further, in the above embodiment, the bill is irradiated with light from a light source and transmitted through the bill, but reflected light may also be used.

As described above, the paper sheet pattern reading device of the present invention has the following features:
It is sufficient to provide only one light source, and a predetermined range including one end of the bill is focused on the first half scanning section of the sensor array, and a predetermined range including the other end of the bill is focused on the second half scanning section of the sensor array, so that the sensor array is aligned. Since it is only necessary to scan in the direction, it is possible to realize the reading of patterns of two specific tracks symmetrical with respect to the central axis of the conveying direction of paper sheets with a simple configuration and control.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the principle of a conventional pattern reading device, and FIG. 2 is a diagram showing the configuration of main parts of another conventional pattern reading device, and FIG. 2 (5) is a plan view thereof. Figure, 2nd
FIG. 1 is a side view of the same side, FIG.
) is the plan view, Figure 6 mark] is the same side view, Figure 4 is the same side view, and Figure 4 is the same side view.
A block diagram showing an electric circuit used in the example device shown in the figure, FIG. 5 is a block diagram specifically showing a change detection circuit of the electric circuit of FIG. 4, and FIG. 6 is a delay diagram of the electric circuit of FIG. 4. FIG. 7 is a block diagram specifically showing the sample and hold circuit of the electrical circuit shown in FIG. 4, and FIG. 8 is a block diagram specifically showing the circuit in FIG. 8 is a diagram showing signal waveforms of various parts of the circuit in FIG. 7. FIG. 6: Banknote, 11: Light source, 13, 14, 15, 1
6: Mirror, 17: Rennes °, 18: Inji sensor, 21: Oscillator, 22: Counter,
23: Multiplier, 24: Comparator. 25: Change detection circuit, 26: Delay circuit. 27: Sample and hold circuit, 28: A-D converter, 29: Memory. Peng Fmata Compilation 4 Memoir 2 Diagram

Claims (1)

[Claims] (1) A sensor array for reading the pattern of paper sheets being conveyed, arranged in a direction intersecting the conveyance direction of the paper sheets, and irradiating at least the width of the paper sheets in the direction intersecting the conveyance direction. A possible single light source and light emitted from this light source that is transmitted or reflected in a predetermined range in a direction crossing the conveyance direction, including one end of one edge of the paper sheet parallel to the conveyance direction. A first group of mirrors condensing light on one side of the divided sensor array, and a direction that intersects with the transport direction, including one end of the other end of the paper sheet that is irradiated by the light source and is parallel to the transport direction. and a second group of mirrors that focuses light transmitted or reflected in a predetermined range of the sensor array onto the other divided side of the sensor array. A sheet of paper characterized in that a pattern of two axially symmetrical tracks at a predetermined distance from both end sides parallel to the conveying direction of the sheet of paper is read on one side and the other fullll where the sensor row is divided. type of pattern reading device.