JPS5936052A - Bill corner bend detecting device - Google Patents

Abstract

PURPOSE:To exactly detect the existence and size of a corner bend by measuring the width of a bill at multiple positions to obtain predetermined number of reference width values and comparing the area of the corner portion with the adjacent area of the reference value portion. CONSTITUTION:A tube-like light source 11 is provided at a right angle to the transport direction (a) of a bill P, the light is scanned by multiple photoelectric elements 13 aligned on the opposite side to the bill P in the width direction so as to detect that a predetermined number of measured values fall within an allowable range. Next, after predetermined (n) scans have been completed, an area is calculated based on the number (n) and length of the scanning lines by a process circuit not shown in the figure. The area of a portion SF, with no corner bend is compared with the area of a corner portion DEF1, and if the difference is a fixed value or more it is judged that a corner bend exists. Thereby, the existence and size of a corner bend can be exactly discriminated regardless of the displacement and size of a bill.

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field of the Invention> The present invention relates to an apparatus for detecting corner folds of paper sheets being conveyed in an inspection device for inspecting the authenticity of paper sheets such as money.

<Technical Background of the Invention> Conventionally, there is a width detection device of this type as shown in FIG. In the figure, P is a sheet of paper being conveyed in the direction of arrow a, ■, 2 is a light source that irradiates light from the upper surface of the conveyed filter paper sheet P, and 3.4 is a sheet of paper facing opposite to this light source l. Photocells 5 and 6 are amplifiers for amplifying the output signals of the photocells 3 and 4, and 6 is a processing circuit to which the output signals of the amplifiers 4 and 5 are supplied. The photocells 3 and 4 are disposed at both ends in the width direction of the paper sheet P to be transported, perpendicular to the transport direction a. When the paper sheets P are being conveyed, the light incident on the photocells 3.4 is cut off in accordance with the amount of corner folds of the paper sheets P being conveyed. The output signals of the photocells 3.4 at this time are amplified by amplifiers 4 and 5, respectively, and supplied to the processing circuit 6, where each of the above output signals is counted, for example, over a certain period of time.
g.

However, in such a conventional corner fold detection device, when a so-called positional shift occurs in the paper sheet P, or there is a change in size of the paper sheet, the photosensor 3, The output of 4 fluctuates greatly (, 2 causes a large error in the count value. In other words, Fig. 1 (c) to (e)
As shown in the figure, the amount of corner folding depends on the misaligned conveyance and the size of the paper sheet! becomes the changed value. For this reason, there was a problem in that the corner fold amount was erroneously detected as being smaller than the normal corner fold amount.

<Objective of the Invention> The present invention has been made in view of the above circumstances, and its object is to measure the width of a plurality of conveyed filter paper sheets and to ensure that at least a predetermined number of measured values are acceptable. By determining whether the paper sheet is within the range, and when this determination is made, predetermined calculations are performed on each of these measured values, and the calculation result is determined as the amount of corner folding of the paper sheet. To provide a highly reliable paper sheet corner fold detection device that can always accurately detect the corner fold amount of paper sheets regardless of the conveyance position shift of the paper sheets or the size of the paper sheets.

<Summary of the Invention> In order to achieve the above object, the present invention measures the width of a paper sheet at multiple locations and determines the difference between the area of a corner fold detection area and the area of an adjacent area within a standard width value. This method is designed to determine the amount of corner bending.

<Embodiment of the Invention> An embodiment of the present invention will be described above with reference to the drawings.

In FIG. 2, P is a paper sheet such as a banknote, which is conveyed, for example, along the longitudinal direction in the direction of the arrow a shown in the figure. Reference numeral 11 denotes a rod-shaped light source (for example, a fluorescent lamp), which is disposed in a direction perpendicular to the conveying direction a, and irradiates light onto the conveyed paper sheets P from the bottom surface thereof. For example, as shown in FIG. Transport area A set as shown. The length is set to sufficiently cover the area. 12 is an optical system that reduces the projection of paper sheet P by the light source 11 to, for example, l/rn; 13 is a line sensor on which the projection reduced by this optical system 12 is formed; and 14 is for driving this line sensor 13. This is a drive circuit. The line sensor 13 is a self-scanning photoelectric converter formed by linearly arranging a large number of solid-state image pickup devices, and is disposed in a direction perpendicular to the transport direction a, for example, in the transport area shown in FIG. A. can be scanned in the direction of the arrow for photoelectric conversion. Therefore, the above-mentioned transport area A. becomes the field of view of the line sensor 13. Here is the above transport area A. For example, as shown in FIG. 3, the first area Al, the second area A2 . It is divided into a third area A3, and the second area A2 is located approximately at the center of the paper sheet P in the width direction. Further, 15 is a detector for detecting the leading edge of the paper sheet P being conveyed, and the light source and the light receiving element are also arranged at a predetermined position in front of the line sensor 13, and its output is The signal is supplied to a processing circuit 18, which will be described later. 16 is an amplifier circuit that amplifies the output signal of the line sensor 13.

A quantization circuit 17 quantizes the output signal of the line sensor 13, which has been amplified by the amplifier circuit 16, bit by bit. In this case, for example, as shown in an enlarged view of the signal waveform for one bit in Fig. 4, slicing is performed at a slice level of approximately 1/2 (VI) It is designed to be quantized by doing this. Further, 18 is a processing circuit that executes various processing operations, which will be described in detail later, based on the output of the quantization circuit 17.

FIG. 5 shows the processing circuit 18 of FIG. 2 in detail. In the figure, reference numeral 21 denotes a timing generation circuit, which synchronizes with the scanning of the line sensor 13 and performs the timing generation circuit 1.1 in FIG. Second. Third area A,,A2. Timing signals T1 y'1'2 and T3 (see Figure 6) specifying A3 are sequentially output, and after outputting the timing signal T3, an interrupt timing signal is generated before outputting the timing signal T1 for the next scan. T,i (see Fig. 6) is output. 22 is an AND circuit that ANDs the output of the quantization circuit 17 and the timing signal T1; 23 is an AND circuit that ANDs the signal obtained by inverting the output of the quantization circuit 17 with the inverter circuit 24 and the timing signal T2; 25 is an AND circuit which ANDs the output of the quantization circuit 17 and the timing signal T3. 26 is a first counter corresponding to the first area A1 in FIG. 2) Count the length (to the top of area A2). 27 is a second counter corresponding to the second area A2 in FIG.
If a hole H (see FIG. 3) exists in the second area A2, its size w4 is counted. 28 is number 3 in Figure 3
AND circuit 25 with the third counter corresponding to area A3.
By counting the output of
3 (the length from the lower end of the second area A2 to the lower end of the paper sheet P). In addition, 29 is a CPU (central processing unit) that performs various data processing, which will be explained later.
0.31 is the address bus and data bus connected to this CPU 29, and 32.33.34 is each of these buses 30.
, 31 and each of the counters 26, 27, 28, and 35 is an R. AM (random access memory),
36 is a bus driver connected between each of the buses 3o and 31 and the detector 15.

Next, the operation of such a configuration will be explained with reference to the flowcharts shown in FIGS. 8 and 9. Now, when the detection operation starts, the CPU 29 first performs step S.
At step 1, it is checked whether the leading edge of the paper sheet P has been detected. In other words, in the blank space below, the CPU 29 activates the bus driver 36 via the address node (30) to activate the detector 1.
The output of 5 is taken in through the data node 31, and
Check whether the output signal of No. 5 has reached the dark level. As a result of this check, if the leading edge of the paper sheet P is detected, that is, if the paper sheet P is being conveyed in the direction of arrow a and the leading edge is detected by the detector 15, the CPU 29 proceeds to step S2. , sets a delay timer built in the CPU 29, and proceeds to step S3.

In step S3, it is checked whether or not the above-mentioned timer has timed out. If it has timed out, the process proceeds to step S4, and the number of lines to capture data (determined in advance according to the size of paper sheet P to be processed) Set n7,
When the line sensor 13 starts scanning the paper sheet P, generally the corners of paper sheets are more likely to be folded or damaged at the leading and trailing ends, so it is better not to use data from those parts. To avoid this, paper sheets P
When the leading edge of the line sensor 13 is detected, a delay timer is set, and after a delay of a certain period of time (1), the line sensor 13 starts scanning by setting the number n of lines to be captured.

When the line sensor 13 starts scanning, as shown in FIG. 7, the line sensor 13 starts scanning the first scanning line [■ 1. The second scanning line H2... is sequentially scanned in the direction of the arrow until the nth scanning line H6, and photoelectric conversion is performed for each line. In this case, the distance between each of the lines is set to, for example, 1 mm. Note that portion B in FIG. 7 indicates a damaged portion such as a tear. , Thus, the output signal of the line sensor 13 is amplified by the amplifier circuit 16 and then supplied to the quantization circuit 17, where it is quantized bit by bit. In other words, k is line sensor 1
When the output signal of 3 is at the dark level (when the paper sheet P receives no light from the light source 11), the '1'' signal is at the bright level (when the paper sheet P receives no light from the light source ti). (when not cut off) is converted into a "°0" signal, and this is done for each bit of the line sensor 13.The quantized ++, u, "0" signals in this way are processing circuit) is supplied to δ.

In the processing circuit 18, the timing signal +111 .
T2. rl13 is sequentially output, and AND circuit 22.
23.25, the first counter 26 receives the output ("l") of the quantization circuit 17 during the period of the timing signal T1.
' signal), the second counter 27 calculates the length Wl in FIG.
If the hole H shown in the figure exists, the output of the quantization circuit 17 ("
o "signal)'f, that hole II by counting
The third counter 28 calculates the magnitude W4 of the timing signal T.
Period 3, output of quantization circuit ■7 (IT III signal)
By counting , the length W3 in FIG. 3 is counted. Then, when the interrupt timing signal T4 is input from the timing generation circuit 21 to the CPU 29 Vc, the CPU 29 proceeds to step S5, and the contents of each counter 26, 27, 28 (each data wl, w4 . W3) Read and import ffi. That is, the CPU 29 activates the bust fibers 32, 33, and 34 via the fdress node 30, thereby reading out the contents of the counters 26, 27, and 28 and importing them into the internal memory. , the CPU 29 proceeds to step S6, stores each of the captured data w1, w4, and w3 in the RAM 35, and proceeds to step S7.In step S7, it is checked whether the number of captured lines has reached n. If not, the process returns to step S5 and the same process as described above is repeated.In this way, for each step from the first scanning line H to the first scanning line H,
Data Wl, w4 for the above 3 foxes. w3 to each counter 26,
27.28, each of the above data is taken into the CPU 29 by the interrupt timing signal T4 generated at the time when each data is determined, and stored in the R and AM 35.

When scanning is completed up to the n-th scanning line H1 in this way, that is, when the number of lines to be captured reaches n in step S7, the CPU 29 stops capturing the data 2, and in step S
Proceed to step 8. In step S8, data wl and w3 for each line stored in the RAM 35 are transferred to the first scanning line H.
The width W of the paper sheet P for each line is determined in step S based on each read data, W2...W
Find n. In other words, a certain scanning line is converted to [■i (i
=1 to n), this scanning line HiO width Wi is given by the following equation.

WH=Vi1+w2 +wi3...(1)
Here, w i l is the length vl in the scanning line Hi, and wi3 is the length w3 in the scanning line Hi. Moreover, w2 is the length of the second area A2 shown in FIG. 3, which is a constant value that does not change. Therefore, if w2 = C (C= constant), the above equation (1) becomes Wi −= C+ will wi3
-(2) can be transformed. The value of Wi is Wl, W2 . . . for each line from the first scanning line H1 to the first scanning line H1. It is given as W3...Wn.

Therefore, by performing the calculation in step S9, the CPU 29 calculates the width W1 for each scanning line. W2. W
3...Wn is determined. After determining the width of each line in this way, the CPU 29 proceeds to step 810.
Proceed to step 1, and calculate each value W1. obtained above. W2. W3...Wn
The final width W of the paper sheet P is determined by.

FIG. 9 describes a specific example of the corner fold discrimination method. As shown in the figure, there are usually four corner fold detection areas, and are indicated by X in the direction perpendicular to the conveyance direction and Y in parallel to the conveyance direction.

X corresponds to Al and A3 shown in FIG.

The width of the area adjacent to the corner fold detection area is determined by the above equation (3), and if it is within the allowed tolerance value, then the value wi
1+ Wiat Wm1. Store Wm3 in memory. If it is out of tolerance (i.e. broken,
If the width is narrow (due to holes, etc.), that value is discarded.

The resolution of the above-mentioned line sensor in the transport direction is, for example, 1 m.
In the case of m, Y=16 mm. The SFI is selected beyond Y from the tip of the ticket and adjacent to the DEFl detection area. For example, i = 20 mm in the same figure. Only when the width at that time from 20 m, m 2 from the leading edge of the paper sheet (corresponding to H2O of the line sensor) is within the allowable value, 16 lines are totaled to determine the standard area SFI. The standard area 8F3 is also calculated using the same procedure. The standard area SDI is determined by summing 16 lines from 20 mm from the trailing edge of the sheet (corresponding to Hn of the line sensor) to the leading edge of the sheet only when the width of the sheet is within the allowable value. Standard area SB3 is also calculated using the same procedure.

In Figure 7, if the leading edge of the paper sheet is Hl and the trailing edge is Hn, then
Corner fold i1 DgFl, I) EF3, DEB, +
DEB3 is determined by the following formula.

DEFt, DEF3, DEBx obtained in this way
DEB3 is compared with the corner bend detection determination level, and if it is outside the allowable value, it is rejected.

FIGS. 10(a) and 10(b) are diagrams for explaining the detection area. Figure (a) shows that when the paper sheet P is conveyed in a misaligned manner (on the right side), the values of DEF+ on the left and right sides are equal and are not affected. Further, FIG. 2B shows the case where the paper sheet P is large (on the right side) and the case where it is small (on the left side), but even in this case, the DEFI is equal on both the left and right sides and is not affected.

In this way, a corner fold detection device with extremely high accuracy can be provided. In addition, Fig. 8(b) shows width discrimination, tear discrimination, skew discrimination,
Hole discrimination and positional deviation discrimination are shown, indicating that they can be determined by processing based on data stored in memory, but this is not the purpose of the present invention and will therefore be omitted. .

Furthermore, since the quantization level in the quantization circuit 17 is always set to about 1/2 of the change due to the paper sheet P, there is almost no error in measurement whether the paper sheet P is new or old. In addition, each area A1 shown in FIG. A2. A
3 is, for example, lOOmm, and the line sensor 18
When is 1024 bits, the resolution in the scanning line direction is given by the following equation.

100 [: rnm] ÷ I O24 = 0.1 [: m
m'J... (5) Therefore, as is clear from the above (5 houses), extremely high accuracy can be achieved extremely easily and at low cost. The case where the field of view of the line sensor is divided into three areas is explained, but the number of divisions can be increased as needed.The resolution of the line sensor in the transport direction and the resolution in the scanning direction are each 1 mm. , 0.1
ROM, but this can also be set arbitrarily depending on the measurement accuracy of the paper sheets to be detected.

<Effects of the Invention> As detailed above, according to the present invention, the widths of the paper sheets being conveyed are measured at a plurality of locations, and it is determined that at least a predetermined number of measured values are within an allowable range. When this determination is made, predetermined calculations are performed on each of these measured values, and the calculation results are classified as corner folds of paper sheets. It is possible to always accurately detect the corner folds of paper sheets regardless of the force, such as, and is highly reliable.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram for explaining a conventional corner fold detection device, FIGS. 2 to 10 are for explaining an embodiment of the present invention, and FIG. 2 is an overall schematic configuration diagram. , Fig. 3 is a diagram for explaining the line sensor's field of view and corner fold detection operation for paper sheets, Fig. 4 is a signal waveform diagram for explaining the quantization method of the quantization circuit, and Fig. 5 is a processing circuit. 6 is a waveform diagram of the timing signal output from the timing generation circuit, FIG. 7 is a diagram for explaining the scanning state of the line sensor, and FIG. 8 is for explaining the entire processing operation. flowchart. FIGS. 9 and 10 are for explaining the corner bend detection area. P... Paper sheets, 11... Light source, I2... Optical system, 1
3... Line sensor, 15... Detector, 17...
Quantization circuit, 18... Processing circuit, 21... Timing generation circuit, 22.23.25 River AND circuit, 26.2
7.28...Counter, 29...CP U35...
・R, A M,. Representative Patent Attorney Noriyuki Chika (and 1 other person) h Tetsudo JL1>z' Figure 2 Figure 5 Figure 6 Figure 7 Figure 8 (Phantom Figure 8 Figure 9
Figure 10

Claims (1)

[Claims] A device for detecting the following includes: a measuring means for measuring the width of a plurality of points on a conveyed filter paper sheet; a discriminating means for discriminating, and a computing means for performing a predetermined operation on each of the measured values when the discriminating means determines that a predetermined number of measured values are within an allowable range; A paper sheet corner fold detection device, characterized in that the paper sheet corner fold detection device is characterized in that the paper sheet corner fold is determined as a corner fold of the paper sheet. (2) The paper sheet corner fold detection device according to claim 1, wherein the calculation means is a detected ball for detecting the amount of corner folds. (3) The width of the adjacent area is within a permissible range. A paper sheet corner fold detection device according to claim 2, characterized in that the value is a value of