JPS6172390A - Scribble pattern detector for printed matter - 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] [Technical Field of the Invention] The present invention is an inspection machine that inspects printed matter such as banknotes for authenticity and fitness, and detects a graffiti pattern written on a Ql riijl object. The present invention relates to a device for detecting graffiti patterns on printed matter.

[Technical Overview of the Invention and Problems Therewith] In recent years, for example, banknote inspection machines have been able to inspect the pages of banknotes (therefore, inspect paper for fitness and separate paper qi; processing machines have advanced to zero speed). , letters in the margins of banknotes,
If a note has graffiti patterns such as symbols or marks written on it, it is required to be treated as an unfit note and not to be recirculated in the market. Shi f knee f,.

Therefore, it is necessary to detect whether there is a graffiti pattern in the margin of the bill or whether it is a cup. Therefore, as a means to detect such graffiti patterns, a well-known optical pattern reading device is used to detect characters and ? It is conceivable to recognize such things as - However, in general, optical pattern reading devices convert the brightness and darkness on the paper into m children using a binary level, so-called similar I
A method is used in which method A is compared with a standard pattern. For this reason, it is impossible to detect a dropped pattern for which no standard pattern exists.

[Object of the Invention 1] The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a graffiti pattern detection device for a printed matter that can reliably detect a graffiti pattern existing on a printed matter 1.

[Summary of the Invention] In order to achieve the above object, the present invention photoelectrically converts light from a printed matter and then converts it into a digital signal, sets a detection area for the printed matter, and detects the above-mentioned signals within the set detection area. The system is configured to determine the presence or absence of a graffiti pattern by adding digital signals and comparing the added value with a preset determination level.

[Embodiment 1 of the invention. □. -Yoriga. , engineering, uke, engineering.

I will explain.

In FIG. 1, numeral 1 indicates a banknote as a printed matter, and for example, as shown in FIG. 2, there is a so-called watermark S at the left end. Hey, P is the design section. Then, this banknote 1 is conveyed in the longitudinal direction in the direction of arrow a in the figure by a conveyor belt (not shown) or the like. Reference numeral 2.3 denotes a fluorescent lamp as a light source for illuminating the surface of the banknote 1 being transported, which is arranged in parallel at a predetermined interval in a direction orthogonal to the transport direction a. 4 is a line sensor as a photoelectric converter, and fluorescent lamp 2
．． 3 in a direction orthogonal to the transport direction a, and the reflected light from the banknote 1 forms an image on the light-receiving surface of the banknote 1 via the optical system 5. Reference numeral 6 denotes a light-receiving element f for detecting the leading edge of the banknote 1 being conveyed, which is disposed opposite to the fluorescent lamp 2 with the banknote 1 interposed therebetween.

The line sensor 4 scans the surface of the banknote 1 in a line and performs photoelectric conversion by being driven to scan by the drive circuit 7 . Since the output of the line sensor 4 is a weak signal, it is amplified by an amplifier 8 and then sent to an A/D converter 9, where it is converted into a digital signal and sent to a processing circuit 10. The processing circuit 10 determines the presence or absence of a graffiti pattern on the banknote 1 based on the digital signal from the A/D converter 9 and the detection gate signal from the timing generation circuit 11.

The timing generation circuit 11 generates a Y-direction detection gate signal YFF (VFR) and an X-direction detection gate signal XFF (XFR) as shown in FIG. 2 based on the output signal of the light receiving element 6 and the signal from the drive circuit 7. That is, the timing generation circuit 11 is configured such that the tip of the banknote 1 being conveyed is connected to the fluorescent lamp 2.
The operation is started by the output signal of the light-receiving element 6 when the light from the light-receiving element 6 is cut off, and by counting the pulses output from the drive circuit 7 every time one scan of the line sensor 4 is completed, for example, the Center point A of the light-receiving cable 6 in Figure 1
If there is a distance of Cmm between the center point B of the line sensor 4 and the center point B of the line sensor 4, the Y direction detection gate signal YFF as shown in FIG.
Create (VFR).

Here, YFF is the Y direction detection gate signal when the banknote 1 is driven in the direction of arrow a in the state shown in FIG.
This is a Y-direction detection gate signal when the banknote 1 in FIG. 2 is conveyed in a state rotated by 180 degrees.

This Y-direction detection gate signal Yrr=(YtrR) is a direction parallel to the conveyance direction of the banknote 1<Yij direction).
This is a signal for setting. In the example shown in FIG. 2, the area where the graffiti pattern is detected is limited to the watermark section S. In addition, the X-direction detection gate signal eXFF (XFR) for setting the direction (X-direction) orthogonal to the transport direction a is as follows:
The starting timing is when the line sensor 4 detects an edge in the direction orthogonal to the conveyance direction of the banknote 1, and the line sensor 4 is generated by counting pulses synchronized with the scanning drive pulses of the line sensor 4 output from the drive circuit 7.

Therefore, in FIG. 2, the Y direction detection gate signal Y
FF (YFR) and X direction detection gate signal XFF (X
A square area E surrounded by FR) becomes a graffiti pattern detection area. Note that the Y direction detection gate signal Y
FF(Yp+n)A';j, and X direction detection gate signal X
The FF (XFR) is held as data in, for example, a ROM (read-only memory) in the timing generation circuit 11. Goo 1-
If it is necessary to detect multiple types of banknotes, a different detection gate signal can be created for each type of scale.

Therefore, as shown in detail in FIG. 3, the banknote 1 is
When the line sensor 4 is scanning the transparent border S of the banknote 1 in the direction W1, if there is a graffiti pattern NP in the watermark S, the output voltage waveform of the amplifier 8 is not shown in FIG. It becomes like this. In Figure 3, [1, 2,...m
l indicates the line scanning position of the line sensor 4, and the interval is determined by the precision required to horizontally press the graffiti pattern NP and the banknote 1.
is determined by the conveyance speed. The graffiti pattern NP appears as a dip in the output voltage waveform of the amplifier 8, and the depth of the dip is expressed as the result of A/D conversion by the A/D converter 9. Therefore, K is the graffiti pattern NP
The value is proportional to the concentration of 1. When the unit is a measurable value determined by the resolution of the trowel and the line sensor 4, the width of the graffiti pattern NP is W as shown in Fig. 4, and the width of the graffiti pattern NP is W as shown in FIG. Then, the length of the graffiti pattern NP is 1-] as shown in FIG. It will be.

i=mD=ΣK; −W
; ・T11+=1 5! ! The output circuit 10 performs the above operation using the output of the A/'D converter 9 to determine the presence or absence of a dropped pattern NP. Zu4I: Straw, timing generation circuit 1
Detection gate signals YFF (VFR), XFF (X
Within the detection area E set by PR), A
The above 1flD is obtained by adding and counting the output of the /D converter 9 with a counter, and by comparing the value with a preset discrimination level JpF (JpR), it is determined whether the value is equal to or higher than the discrimination level JFF (JFR). In this case, it can be easily determined that there is a graffiti pattern NP. Note that JFF is the discrimination level when the banknote 1 is punched in the direction of arrow a in the state shown in Fig. 2, and compared with the discrimination level JFR when the banknote 1 in Fig. 2 is conveyed in a state rotated 180 degrees. I will do it.

In this way, after photoelectrically converting the reflected light from the banknote 1, A/
D conversion is performed, and the Δ/D conversion output is used as the detection gate signal YFF(VFR,),X from the timing generation circuit 11.
F
By detecting the size and density of the graffiti pattern NP, the presence or absence of the graffiti pattern NP is determined. As a result, banknote 1
For example, r
K1 can actually be detected.

Note that the method of performing the calculation using the data after A/D conversion is performed by hardware when the conveyance speed of banknotes is high and high-speed processing is required.
There is also a method of reading it into the CPU and making a determination. In addition, for the sake of simplicity, explanation 3 has been explained about the case where the graffiti pattern on the front side of the banknote is detected, but since the graffiti pattern on the back side is also usually detected, the same detection device VI is installed on the top and bottom of the banknote.
It is common to set (!-).

Further, in the above embodiment, a case has been described in which a graffiti pattern written on paper 1j (3) is detected, but the present invention is not limited to this, and detection is performed on other printed matter such as securities other than banknotes. It can also be applied to the detection of graffiti patterns written on.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to provide a pattern detection device for dropping patterns on printed matter that can reliably detect graffiti patterns existing on printed matter.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention; FIG. 1 is an overall configuration diagram; FIG. 2 is a diagram showing an example of a banknote and its detection gate signal; and FIG. 3 is a diagram for explaining the operation. figure,
FIG. 4 is a diagram illustrating the shape of a graffiti pattern. 1...Banknotes (printed matter), 2.3...Light source, 4...
Line sensor (photoelectric converter), 9...A, /D converter, 10...processing circuit, 11...timing generation circuit, YFF, YFR, XFF, XFR...1 middle 2,
11 Goo 1- IY, E... detection area, NP...
・Doodle pattern.

Claims (3)

[Claims] (1) A light source that illuminates the printed matter being transported, a photoelectric conversion means that converts the light from the printed matter illuminated by this light source into an electrical signal, and an A/D conversion means that converts the output of the photoelectric conversion means into a digital signal. and an area setting means for setting a detection area for the transported printed matter; and an area setting means for setting a detection area for the printed matter to be transported;
What is claimed is: 1. A graffiti pattern detection device for a printed matter, comprising: a discrimination means for determining the presence or absence of a graffiti pattern by adding the outputs of the conversion means and comparing the added value with a preset discrimination level. (2) The apparatus for detecting graffiti patterns on printed matter according to claim 1, wherein the detection area set by the area setting means is a blank area of the printed matter. (3) The graffiti pattern detection device for a printed matter according to claim 1, wherein the printed matter is a banknote.