JPS59153282A - Discriminator 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 relates to a printed matter discrimination device for determining the authenticity of printed matter such as banknotes.

[Technical background of the invention and its problems]

In the past, various types of discrimination devices have been proposed for discriminating, for example, the authenticity of banknotes, but most of them apply optical methods. For example, by focusing on a specific part of a pattern printed on a banknote and detecting the light reflectance or light transmittance of one color at that part, whether the detected value matches the reference value or not. If you checked whether or not, or II Q
There is a method of checking whether the pattern when replaced with the "1" signal matches the reference pattern.

However, 1. This method involves temporarily stopping the banknotes being transported and irradiating light onto specific areas during the pause period, so not only does it take a long time to identify the banknotes, but the banknotes that are being transported may be misaligned. If there is, a positional shift occurs between the detection position (the location where light is irradiated) and the specific location, making accurate determination impossible. In addition, even if the banknote itself is genuine, if there are stains or stains in certain areas,
Since the entire bill is determined based on information about only that part, there is a risk that the banknote may be mistakenly determined to be inauthentic. As described above, the above method has a problem in that the discrimination accuracy is affected by the conveyance state of the banknote, local dirt, etc.

Further, as another example of a conventional discrimination device, those shown in FIGS. 1 and 2 are known.

This discrimination device consists of a detection section and a signal processing section, FIG. 1 shows the detection section, and FIG. 2 shows the signal processing section. That is, the detection unit is composed of a housing 11, a light source 2, a reflecting mirror 3, a lens 4, a transparent partition plate 5, and a light receiving element 6, and the bill P is conveyed at a constant speed inside the housing. .

The light from the light source 2 is reflected by the reflecting mirror 3 and travels upward in the figure, and passes through the lens 4, the slit 7, and the transparent partition plate 5 in the width direction of the banknote P (direction perpendicular to the transport direction). uniformly illuminate. Due to this illumination, the light that has passed through the banknote P is guided to the light receiving element 6 through the slit 8 and converted into an electric signal. Therefore, when the banknote P passes over the slit 7, a distorted wave signal of a time function corresponding to the pattern of the banknote P is obtained from the light receiving element 6.

The signal thus obtained from the detection section is sent to the signal processing section. That is, the output of the light-receiving element 6 is amplified by an amplifier 9, and then supplied to a plurality of band filters 101 to 1On, where it is divided into a plurality of sine wave components of specific frequencies. It is integrated by integrators Ill-jln connected to 101-JOn, respectively. And banknote P
After passing through the slit 7, the switch 12'l is turned on.
-1271 is turned on, each output of the integrators ljl to JJn is supplied to the comparator 13, and compared with a reference value corresponding to a genuine banknote stored in advance in the storage unit 14, the banknote It is designed to determine the authenticity of P.

However, the conventional discrimination device described above has the following problems. That is, the output of the light receiving element 6 is a distorted wave signal that depends on the pattern of the banknote P, but since the banknote P being conveyed is detected through a wide slit, it is difficult to increase the resolution. It is. therefore,
The output (distorted wave signal) of the light receiving element 6 does not strictly indicate the characteristics of the pattern of the banknote P, but is a rough pattern converted into an electrical signal. Then, the output of the light receiving element 6 is input to the wave leakers 101 to 10n, so that only the sine wave component of the distorted wave signal is extracted. As a result, for example, in the case of counterfeit banknotes using a copying machine, the patterns of the genuine and counterfeit banknotes are almost the same, so the electrical signals obtained from each leaker 101 □ 10n are almost the same as the genuine banknotes. In any case, it becomes difficult to accurately identify counterfeit banknotes.

Still, the output signal of the light receiving element 6 amplified by the amplifier 9 is
It is divided into frequencies by a plurality of leakers 101 to 10n, and then passed through integrators 111 to lln, and the reference value stored in the storage unit 14 is based on the value when genuine banknotes are transported in advance. Each integrator 11. Since the electric signal is obtained from .

If the conveying speeds do not match or the orientation of the banknotes is not constant due to skew, etc., the pattern signal obtained from the amplifier 9 changes, and the output of each leaker 103 to 1On changes. As a result, the outputs of the integrators 111 to lln also change, and as a result, errors occur in the comparison and discrimination by the comparator No. 3. Therefore, the permissible value of the comparison limit in the comparator 13 must be expanded by taking into account the change in the conveyance speed, but widening the permissible value means that
On the other hand, it means lowering the discrimination accuracy.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to provide a printed matter discrimination device that can accurately distinguish between genuine printed matter and counterfeit printed matter, and in which the discrimination result is not affected by the transportation state of the printed matter, etc. Our goal is to provide the following.

[Summary of the invention]

The printed matter discriminating device according to the present invention can produce counterfeit printed matter (for example, banknotes forged by a copying machine) with almost the same pattern as genuine printed matter; ), we focused on the fact that there is a large difference in color distribution, and designed it to be able to distinguish between genuine prints and counterfeit prints based on the state of color distribution.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

3 and 4 show a discriminating device according to the present invention, which includes a detection section (FIG. 3) and a signal processing section (FIG. 4) similar to the conventional example shown in FIGS. 1 and 2 described above. ). In FIG. 3, banknote P is conveyor bell) 21 +
21 +... are held and conveyed in the direction of the arrow shown in the figure. A predetermined area in the width direction of the transported banknote P is uniformly illuminated by an illumination unit 22 installed on the upper surface side thereof. The illumination unit 22 includes a light source 23, a condensing lens 24, and a transparent guide 25 that functions as a slit. Thus, the light that has passed through the banknote P is received by the light receiving unit 26 installed on the lower surface side of the banknote P facing the illumination unit 22. This light receiving unit 26
includes a diffuser/guide plate 27 and, for example, three light receiving elements 281 . 282. 283, and the light transmitted through the banknote P is uniformly received by each of the light receiving elements 281 to 283.

Here, each of the light receiving elements 281 to 283 has a different wavelength sensitivity and receives transmitted light in a plurality of bands.

An example of the wavelength sensitivity of each of the light receiving elements 281 to 283 is shown in FIG. In the figure, curve A shows the spectral sensitivity of the light receiving element 281, curve B shows the spectral sensitivity of the light receiving element 282, and curve C shows the spectral sensitivity of the light receiving element 283. A light receiving element having these spectral sensitivities can be easily realized by, for example, combining a silicon photodiode with an appropriate colored glass filter.

FIG. 6 shows the relationship between the illumination and light-receiving area and the conveyance position of the banknote, where P is the banknote, 29 is the illumination and light-receiving area,
The transparent area in FIG. In this figure, the banknotes P are conveyed in the direction of the arrow across the area 29, but the area 29 is set as wide as necessary so that the banknotes P do not protrude from the area 29 and are conveyed. By doing so, it is possible to eliminate the shift in the transport position of the banknotes P and the influence of skis.

In this way, when the bill P passes through the area 29 and the transmitted light is received by each of the light receiving elements 281 to 283 and converted into an electrical signal, each of the light receiving elements 28. The outputs of 283 to 283 are sent to the signal processing section shown in FIG. That is, each light receiving element 281.

The outputs of 282+283 are respectively sent to amplifiers 3 and 3.

After being amplified by 312+313, the integrator 321°322
．． 323' respectively. Further, 33 is a leading edge detector that optically detects the leading edge of the banknote P being conveyed in front of the aforementioned detection section and generates a leading edge signal. This tip signal is supplied to a timing generation circuit 34, which in turn instructs each integrator 32. A timing signal is generated to control the integration timing of ~323. The above-mentioned integration timing is the time from when the banknote P reaches the area 29 to when it finishes passing there.

In this way, the signals integrated by each integrator 321 to 323 for a predetermined time, that is, the output signal Vll + V12 + V13 of each integrator 321 to 323, are respectively supplied to the adder 35, so that the adder 35 The signals V11-"V13 are added, and the addition result signal Y is outputted. This signal Y is supplied to dividers 361, 362, and 363, respectively, so that the divider 3fH divides the signal Vtt by the signal Y and outputs the signal Y. The divider 362 divides the signal V12 by the signal Y to obtain the signal v22, and the divider 363 divides the signal VtS by the signal Y to obtain the signal V23. Each of the thus obtained signals Vllll V1
21 V131 Y + Vzxt V221 V23
are respectively supplied to the selection circuit 37. Here, 38 is the selection circuit 37 and the reference voltage setting circuit 40 described later.
A type discrimination circuit that specifies the bill type (specifies the type of banknote P) for automatically distinguishing the type of banknote P to be conveyed by detecting its shape and other characteristics, and then automatically distinguishing the type of banknote P based on the determination result. Specify the species. The type discrimination by the type discrimination circuit 38 is carried out as follows. That is, as shown in FIG. 7, two optical detectors S1+S'2 are placed at a predetermined interval (a distance shorter than the length of the smallest banknote) in parallel to the conveyance direction of the banknote P in front of the above-mentioned detection unit. The length of the banknote P in the transport direction is detected and the type of banknote P is determined by measuring the time from when the detector St becomes dark to when the detector S2 becomes bright. It is.

Therefore, in the selection circuit 37, according to the bill type specified by the type discrimination circuit 38, each signal V11-V1 is inputted as the most effective signal when determining the authenticity of the bill type.
3, Y, and V21 to V23, and supplies the selected signal to the comparator 39. Reference numeral 40 denotes a reference voltage setting circuit in which reference voltages for all ticket types are stored, and when a bill type is specified in the bill type discriminating circuit 38, a reference voltage corresponding to the bill type is selected. , and supplies it to the comparator 39. As a result, the comparator 39 is supplied with a signal and a reference voltage most suitable for the type of bill to be discriminated. Thus, the comparator 39 determines the authenticity of the banknote P by comparing the signal supplied from the selection circuit i7 with the reference voltage supplied from the reference voltage setting circuit 40. Note that the reference voltage of each bill type stored in the reference voltage setting circuit 40 is a value determined in advance by passing a genuine bill through this discriminating device.

In this way, the transmitted light of the banknote P is photoelectrically converted by the plurality of light receiving elements 28□ to 283, each having a different spectral sensitivity, and each of the outputs is integrated for the period during which the banknote P passes through, and then the integrated outputs are added. , calculate the ratio between this addition result and each of the above-mentioned integral outputs, select the most suitable signal for the ticket type from among these respective calculation results and each of the above-mentioned integral outputs,
Authenticity is determined by comparing this selected signal with a reference voltage. Therefore, the time required for discrimination is short, and the influence of positional deviation during transportation, local dirt, etc. is removed, and reliable and accurate discrimination is possible. Since the discrimination is based on the distribution ratio of the hue over the entire surface of the banknote, it is possible to accurately and easily identify a banknote forged using a copying machine or the like with almost the same number of turns as a genuine banknote. Further, in the configuration as described above, only one reference voltage generation circuit is required.

In addition, although the said Example demonstrated the case where the transmitted light of a banknote is photoelectrically converted, it may be made to photoelectrically convert the reflected light. In addition, although the type of banknote is automatically specified by the type discrimination circuit, the present invention is not limited to this, and an operator may manually specify the type using a switch, for example, on the operation panel of a banknote sorting machine in which the device of the present invention is used. You can do it like this. Further, although the description has been made regarding the case where the present invention is applied to determining the authenticity of banknotes, the present invention is not limited to this, and can also be applied to determining the authenticity of securities other than banknotes.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide a printed matter discriminating device that can accurately discriminate between genuine printed matter and counterfeit printed matter, and in which the discrimination result is not affected by the conveyance state of the printed matter or the like.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the detection section of a conventional discriminator, FIG. 2 is a block diagram showing the signal processing section of the conventional discriminator, and FIG.
The figures to FIG. 7 show one embodiment of the present invention.
The figure shows the configuration of the detection unit, Figure 4 is a block diagram of the signal processing unit, Figure 5 shows the spectral sensitivity characteristics of the light receiving element, and Figure 6 shows the relationship between the conveyance state of banknotes and the illumination and light receiving area. FIG. 7 is a schematic diagram for explaining the type discrimination circuit. P... Banknotes (printed matter), 2... Conveyor belt, 22
... Lighting unit, 23... Light source, 26... Light receiving unit, 281-283... Light receiving element, 321-3
23... Integrator, 35... Adder, 361-363
... Divider, 37... Selection circuit, 38... Type discrimination circuit, 39... Comparator, 40... Reference voltage setting circuit. Representative Patent Attorney Kensuke Chika (and 1 other person) 1st
Figure 2 Figure 3

Claims (3)

[Claims] (1) A light source that irradiates light onto the printed matter being conveyed;
A plurality of light-receiving elements each having a different spectral sensitivity receive reflected light or transmitted light from the printed material to be discriminated by this light source and convert it into an electrical signal, and a predetermined calculation process is performed by combining the outputs of these light-receiving elements. means, a specifying means for specifying the type of printed material to be discriminated, a selecting means for selecting an output of the light receiving element or an output of the calculating means according to the specification of the specifying means, and an output selected by the selecting means. What is claimed is: 1. A printed matter discriminating device comprising: a discriminating means for discriminating the authenticity of a printed matter to be discriminated by comparing it with a reference signal set in advance. (2) The printed material discriminating device according to claim 1, wherein the designation means is a type discriminating means that automatically discriminates the type by detecting the characteristics of the printed matter to be discriminated. (3) The printed matter discriminating device according to claim 1, wherein the specifying means is a manual specifying means for manually specifying the type of printed matter to be discriminated.