JPH0636206B2 - Paper discriminating device - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a paper sheet discriminating apparatus for discriminating the authenticity of a bill, for example.

[Technical background of the invention] Conventionally, as a paper sheet discriminating apparatus of this type, for example, light from a light source is constantly applied to a standard plate, and reflected light (or excitation light) from the standard plate is used as a reference. There is one that determines the authenticity of a bill depending on the amount of reflected light (or the amount of excitation light) from the bill when the conveyed bill blocks the light from the light source. FIG. 1 shows an example of the configuration. In the figure, reference numeral 1 is a dark box in which bills P are conveyed in the direction of the arrow a in the figure.
A light source 2 and a light receiver 3 for timing generation are provided to face each other on the banknote carry-in side in the dark box 1. A light source 4 for irradiating the conveyed banknote P with light, a standard plate 5 for irradiating light from the light source 4 when there is no banknote P, a banknote P for conveyance, and a substantially central portion in the dark box 1. A light receiver 7 is provided for receiving the reflected light from the standard plate 5 via the filter 6. Then, when the bill P is not conveyed, the light from the light source 4 is constantly applied to the standard plate 5,
The reflected light from the standard plate 5 is guided to the light receiver 7 through the filter 6 and photoelectrically converted. When the banknote P is conveyed and reaches the position of the standard plate 5, the light from the light source 4 is emitted, and the reflected light from the banknote P is guided to the light receiver 7 through the filter 6 and photoelectrically converted. To be done. This light receiver 7
Output to the processing circuit (not shown), the amount of reflected light from the bill P when the conveyed bill P blocks the light from the light source 4 with reference to the reflected light from the standard plate 5. The authenticity of the bill P is determined by.

[Problem of Background Art] However, in the above-described conventional configuration, since the standard plate 5 is exposed on the conveyance surface of the banknote P, dust on the standard plate 5,
When dust adheres, the amount of reflected light changes and the standard plate 5
Since the amount of reflected light of the banknote P, which is detected based on the amount of reflected light of the banknote P, becomes unstable, there is a problem that the authenticity of the banknote P cannot be accurately determined. Further, if there is a hole or a tear in the paper sheet, the reflected light from the standard plate may enter the light receiver and cause a false detection.

[Object of the Invention] The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent the influence of dust, dust, and the like, and to accurately determine the authenticity of a paper sheet. It is to provide a classifier.

[Summary of the Invention] In order to achieve the above-mentioned object, the present invention provides a dark box, a conveyance means for forming a conveyance path in the dark box, and conveying paper sheets in a predetermined side direction along the conveyance path. A standard plate installed in a width direction of a side orthogonal to the predetermined side direction of the paper sheet conveyed by the conveying means and outside the conveyance range of the paper sheet, and the standard plate And a light source for irradiating the paper sheet conveyed by the conveying means with light,
Light receiving means for simultaneously receiving the reflected light from the standard plate and the reflected light from the paper sheet irradiated with light by the light source and converting it into an electric signal, and receiving the output of the light receiving means, the paper sheet is Difference calculating means for subtracting the output when there is no paper sheet from the output when it exists, integrating means for integrating the output of this difference calculating means for a predetermined period, and the output from this integrating means for a predetermined reference value. It is characterized by further comprising a comparing means for comparing with the above, and a judging means for judging the paper sheet based on the comparison result from this comparing means.

Therefore, since the standard plate is arranged at a position outside the paper sheet conveyance range, dust, dust, etc. are less likely to enter, and a fixed amount of reflected light is not affected by the paper sheet shape and conveyance state. You can receive from the standard board. As a result, the reflected light from the paper sheet can be stably received, and the paper sheet can be accurately determined.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. It should be noted that the same parts as those in FIG. In FIGS. 2 and 3, reference numeral 1 denotes a dark box (closed box) in which bills P are conveyed in the direction of arrow a in the figure. A light source 2 for timing generation and a light receiver (for example, a photodiode) 3 are provided to face each other on the banknote carry-in side in the dark box 1. Further, in a substantially central portion of the dark box 1, a light source 4 for irradiating the conveyed banknote P with light, a standard plate 5 with which the light from the light source 4 is irradiated, and a light from the light source 4 when the banknote P is not present. Light-shielding plate 8 as a light-shielding member for irradiating light, a bill 9 conveyed, a lens 9 for guiding light from the standard plate 5, and an optical fiber 1.
0, a light receiver (for example, a photodiode) 7 that receives light guided by these through a filter (having a sensitivity to a blue wavelength) 6 is provided. The light source 4 is, for example, a light source for irradiating ultraviolet rays, and detects the fluorescent whitening agent component contained in the banknote P. Also, the standard plate 5
Is coated with a fluorescent substance inside and is arranged at a position outside the detection field of view (conveyance range of the banknote P) as shown in FIG. 3, so that the light from the light source 4 is constantly irradiated. It has become. Furthermore, at least the surface (the surface to which light is irradiated) of the light shielding plate 8 is painted black, and is arranged to face the light source 4 with the banknote P being conveyed in between.

In such a configuration, the banknote P is conveyed, first passes through the timing generating light receiver 3, and reaches the position of the standard plate 5, whereupon the light source 4 emits ultraviolet rays. The light excited by the applied ultraviolet rays enters the optical fiber 10 via the lens 9. The standard plate 5 is constantly irradiated with ultraviolet rays from the light source 4, and is emitted by being irradiated with the ultraviolet rays, and the light is incident on the optical fiber 10 via the lens 9. The optical fiber 10 combines the light from the banknote P and the light from the standard plate 5 into one, and guides this light to the light receiver 7 via the filter 6. Normally, the bill P does not contain a fluorescent whitening component, but a copy made by a copying machine or the like contains a fluorescent whitening component. This is because the commercially available paper itself contains a bleaching agent for whitening the color. When the banknote P containing the fluorescent whitening agent component is irradiated with ultraviolet rays, the banknote P emits a pale white light. This bluish-white light is detected by the light receiver 7 via the filter 6. In the case of a genuine correct bill, since the fluorescent whitening agent component is not included, the excitation light does not enter the light receiver 7, but only the light from the standard plate 5 enters.

On the other hand, the light-shielding plate 8 is painted black on its surface as described above, and normally light other than the standard plate 5 is incident on the light receiver 7 in the state where there is no banknote P and the banknote P has a hole. In this case, it is possible to prevent unnecessary light from entering and to detect the entire surface including the edge of the bill P. Further, since the standard plate 5 is arranged at a position outside the detection field of view of the banknote P, it is difficult for dust, dust, and the like to enter, and the light from the standard plate 5 can always be received even while the banknote P is being transported. The amount of light of the banknote P itself is obtained by subtracting the amount of light when there is no P from the detection visual field. The purpose of arranging the standard plate 5 is to diagnose the light source 4 (whether or not it is lit).
And as a reference for determining the gain of the processing circuit described later.

FIG. 4 shows an example of the processing circuit. That is,
The timing generating photodetector 3 is connected to an amplifier 11, and the output of the photodetector 3 whose level is amplified by the amplifier 11 is input to a timing generating circuit 12. The timing generation circuit 12 generates timing signals T ₁ and T ₂ used in this processing circuit. Further, the photodetector 7 is connected to an amplifier 13, and the output of the photodetector 7 whose level is amplified by the amplifier 13 is a zero clamp circuit 14 and a differential amplifier 1.
5, and the level when the bill P is not present is subtracted from the level when the bill P is in the detection visual field. That is,
[(Light quantity of banknote P + light quantity of standard plate 5)-(light quantity of standard plate 5) = light quantity of banknote P] is obtained and input to the comparator 16 as an electric signal and the comparator via the integrator 17. 1
8 is input. This is because when a banknote is copied on paper containing a fluorescent whitening agent component, the amount of output signal differs depending on the amount of the printed pattern, and when there is an overall pattern, it appears at a certain level in the entire banknote, so the raw signal It is impossible to cut the level directly with, and in this case it is easier to make a difference by integrating. Further, when there is a part of white background where there is no pattern, it is easier to discriminate directly by level cutting with a raw signal. For this reason, a comparator 1 for directly comparing raw signals
6 and a comparator 18 for comparing the signals integrated by the integrator 17, and the respective comparators 16 and 18 compare with the reference levels L ₁ and L ₂ from the reference value generation circuit 19 and the respective comparison results. Is input to the determination circuit 20. Judgment circuit 20
Determines whether the bill P is true or false by performing various determination calculations using the outputs of the comparators 16 and 18, and outputs the determination result. That is, the determination circuit 20 calculates the logical sum of the output signals of the comparators 16 and 18,
If a "1" signal is obtained, it is determined that the bill is a counterfeit bill,
If a "0" signal is obtained, it is determined that the bill is a genuine bill. The timing chart of the processing circuit described above is shown in FIGS. Note that (b)
The figure (e) shows the case of a genuine banknote, the figures (c) and (f) show the case of a partially abnormal banknote, and the figures (d) and (g) show the case of an entirely abnormal banknote. .

With the configuration as described above, by disposing the standard plate 5 at a position away from the bill conveying surface, the influence of dust, dust, etc. is prevented, and even if the bill has holes or tears, The amount of light from the standard plate and the stable amount of light of the bill can be obtained, and the authenticity of the bill can be accurately determined.

In addition, in the above-described embodiment, the case where the light source for ultraviolet irradiation is used as the light source 4 and the fluorescent whitening agent component contained in the bill is detected has been described, but the light source 4 may be a fluorescent lamp, a tungsten lamp, or a halogen lamp. The detection target may be the color component of the bill or the degree of contamination. Further, the light source 4 is located in front of the light receiver 7 with respect to the conveyance direction of the banknote P, but may be located in the opposite rear side. Further, although the timing generating light receiver 3 is provided with the light source 2 independently,
May be used.

In addition, in the above-described embodiment, the case where the invention is applied to the authenticity determination of the bill has been described, but the present invention is not limited to this, and for example, a check, a certificate other than the bill, or a printed matter or other paper sheets. It can also be applied to the authenticity or the quality judgment of

[Effects of the Invention] As described in detail above, according to the present invention, the influence of dust, dust, etc. is prevented, and even when there are holes or tears in paper sheets, a certain amount of light from a standard plate and stable bill It is possible to provide a paper sheet discriminating apparatus that can obtain the amount of light and accurately determine the authenticity of a paper sheet.

[Brief description of drawings]

FIG. 1 is a side view schematically showing a conventional paper sheet discrimination apparatus,
2 to 5 show an embodiment of the present invention.
2 is a side view, FIG. 3 is a front view, FIG. 4 is a block diagram of a processing circuit, and FIG. 5 is a timing chart for explaining the operation. P: Banknotes (paper sheets), 1 ... Dark box (closed box), 4 ...
Light source, 5 ... Standard plate, 7 ... Photoreceiver, 14 ... Zero clamp circuit, 15 ... Differential amplifier, 17 ... Integrator, 16,
18 ... Comparator, 19 ... Reference value generation circuit, 20 ... Judgment circuit.

Claims (1)

[Claims] 1. A dark box, a conveying means for forming a conveying path in the dark box, and conveying paper sheets in a predetermined side direction along the conveying path, and the paper sheet conveyed by the conveying means. A standard plate installed in the width direction of the side orthogonal to the predetermined side direction of the paper sheet and outside the paper sheet carrying range, and the paper sheet carried by the standard board and the carrying means. A light source for irradiating light with respect to the class, a light receiving means for simultaneously receiving the reflected light from the standard plate and the reflected light from the paper sheet irradiated with light by the light source, and converting the light signal into an electric signal; A difference calculating means for receiving the output of the light receiving means and subtracting the output when the paper sheet does not exist from the output when the paper sheet exists, and an integrating means for integrating the output of the difference calculating means for a predetermined period. , A comparator for comparing the output from this integration means with a predetermined reference value A sheet discriminating apparatus comprising: a stage; and a discriminating unit for discriminating the sheet based on a comparison result from the comparing unit.