JPH0579996A - Stuck object judging device - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention reliably discriminates the adhered matter of a paper sheet without misjudging. [Constitution] Irradiating the inspected object (3) with a wavelength of light having a common absorption for the inspected object (3) output from the light source (10) and the attached matter (4) of the inspected object (3). Then the transmitted light is received by the receiver
Receive light by (12). Then, receiving the amount of received light, the discriminating means (13) discriminates the presence or absence of the adhered matter (4) with respect to the inspection object (3). Further, the light transmitted through the object to be inspected (3) is received by the first light receiver (12) and the reflected light from the object to be inspected (3) is received by the second light receiver (20). ) To obtain the ratio of these received light amounts, the adhered matter (4) to the inspected object (3)
The presence or absence of Further, the output signal of the photodetector is logarithmically converted by the logarithmic conversion circuit (34), and the conversion means receives the output and the adhering matter (4) with respect to the inspection object (3) is discriminated by the discrimination means (35).
The presence or absence of

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhering matter discriminating apparatus for discriminating the presence or absence of a tape attached to a paper sheet, for example.

[0002]

2. Description of the Related Art As a technique for discriminating a tape attached to a paper sheet, for example, a tape attached to restore paper, rollers 1 and 2 are provided as shown in FIG. A method of measuring the thickness of the tape 3 by inserting the paper sheet 3 into the tape is used. Therefore, when the portion where the tape 4 is attached passes between the rollers 1 and 2, the distance between the axes of the rollers 1 and 2 at this time becomes long. As another technique, as shown in FIG. 13, the sheet 3 is irradiated with visible light, the transmitted light is received by the light receiver 5, and the presence or absence of the tape 4 is determined from the amount of the received light.

However, in the technique using the rollers 1 and 2, when the folds of the paper sheet 3 pass between the rollers 1 and 2, the rollers 1 and 2 as well as the portion where the tape 4 is attached.
The distance between each axis becomes longer. Therefore, the fold line of the paper sheet 3 is erroneously determined as the portion to which the tape 4 is attached. or,
Since the rollers 1 and 2 are consumed, maintenance of these rollers 1 and 2 is difficult.

Further, in the technique using visible light, the amount of transmitted light changes depending on the type of the tape 4 and the presence / absence of printing on the sheet 3 to make an erroneous determination. For example, since visible light is almost transmitted through both cellophane tape and transparent vinyl tape,
Even if these tapes are attached, it is erroneously determined that they are not attached.

[0005]

As described above, in each tape discrimination technique, the tape is erroneously discriminated. Therefore, an object of the present invention is to provide a highly-reliable adhering matter discriminating apparatus capable of surely discriminating an adhering matter on a sheet without making a mistake.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a light source that outputs a light having an absorption wavelength that is common to an object to be inspected and an adhered object of the object to be inspected, and a light source output from the light source and transmitted through the object to be inspected. An adhering matter discriminating apparatus, which is provided with a light receiver for receiving light and a discriminating means for discriminating the presence or absence of an adhering substance on an object to be inspected based on the amount of light received by the light receiving device.

Further, according to the present invention, a light source which outputs a light having an absorption wavelength common to an object to be inspected and an object to be adhered to the object to be inspected, and light emitted from the light source and transmitted through the object to be inspected are received. The presence or absence of an adhering substance to the inspection object is determined by the first light receiving device, the second light receiving device for receiving the reflected light of the inspection object, and the ratio of the respective received light amounts received by the first and second light receiving devices. An adhering matter discriminating apparatus, which is provided with a discriminating means and is intended to achieve the above object.

Further, according to the present invention, a light source which outputs a light having an absorption wavelength common to the object to be inspected and a substance attached to the object to be inspected, and a light receiving device which receives the light output from the light source and transmitted through the object to be inspected. A logarithmic conversion circuit for logarithmically converting the output signal of the photodetector, and a discrimination means for discriminating the presence / absence of an adhered substance on an object to be inspected by the output of the logarithmic conversion circuit are provided. It is a kimono discrimination device.

[0009]

By providing such means, the absorption wavelength light which is common to the object to be inspected and the object to be adhered to the object to be inspected is output from the light source to irradiate the object to be inspected. The light that has passed through is received by the light receiver. And
The determination means receives the signal output from the light receiver and determines the presence / absence of an adhered substance on the inspection object.

Further, similarly to the above, the absorption wavelength light which is common to the object to be inspected and the object to be adhered to the object to be inspected is irradiated to the object to be inspected, and the light transmitted through the object to be inspected at this time is first received. The second light receiver receives the reflected light of the inspection object. Then, the determination means determines the ratio of the output signals of these light receivers to determine the presence / absence of an adhered substance to the inspection object.

Further, similarly to the above, the absorption wavelength light which is common to the object to be inspected and the adhered material to the object to be inspected is applied to the object to be inspected, and the light transmitted through the object to be inspected is received by the light receiver. .. Then, the output signal of the light receiver is logarithmically converted by the logarithmic conversion circuit, and the discriminating means receives the converted output and discriminates the presence / absence of an adhered substance to the inspected object.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an adhering matter discriminating device for a tape attached to a paper sheet. A laser oscillator 10 is provided, and the laser light output from the laser oscillator 10 is reflected by the mirror 1
1, the paper sheet 3 is irradiated with the light. This laser oscillator 10 is a He-Ne laser and has an oscillation wavelength of 3.4 μm.
The laser light is output.

By the way, when the sheet 3, for example, a bill and a tape, were measured by a Fourier transform infrared spectrophotometer, the absorption wavelength shown in Table 1 was obtained as a wavelength having a large absorption.

[0015]

[Table 1]

As can be seen from these results,
The absorption wavelength common to each part such as blue printing and multicolor printing is
It is 3.4 μm. Therefore, the oscillation wavelength of the laser oscillator 10 is set to 3.4 μm.

Further, a light receiving element 12 is arranged at a position facing the mirror 1 with the paper sheet 3 in between. This light receiving element 1
2 comprises an infrared detector such as PbSe,
It outputs an electrical signal according to the amount of received light. This light receiving element 12
The electric signal output from the device is sent to the discriminating device 13.

The discriminating device 13 has a function of discriminating the presence or absence of the tape 4 with respect to the paper sheet 3 based on the signal output from the light receiving element 12, that is, the amount of transmitted light in the paper sheet 3, and the tape 4 is attached. The output signal of the part is reduced.

A chopper 14 is provided in the optical path of the laser beam output from the laser oscillator 10, and the discrimination result of the discriminating device 13 is displayed on the display device 15.

With this structure, the laser beam having a wavelength of 3.4 μm output from the laser oscillator 10 is chopped by the chopper 14 and reflected by the mirror 11 to be reflected by the paper sheet 3.
Is irradiated. At this time, the paper sheet 3 is conveyed in the arrow (a) direction by the conveying device. The light receiving element 12 receives the laser light transmitted through the paper sheet 3 and outputs an electric signal according to the received light amount. Here, when the portion to which the tape 4 is attached is irradiated with laser light, the absorption rate for the wavelength of 3.4 μm becomes larger than that of the paper sheet 3 alone. FIG. 2 shows the output level of the light receiving element 12 of only the paper sheet 3, and FIG. 3 shows the output level of the light receiving element 12 of the portion where the tape 4 is attached. Therefore,
The determination device 13 determines from the output level of the light receiving element 12, that is, the amount of light received by the light receiving element 12 that the tape 4 is not present when the output level is shown in FIG. 2, and the tape 4 is present when the output level is shown in FIG. Determine.

As described above, in the first embodiment, the sheet 3 is irradiated with the laser beam having the wavelength of 3.4 μm output from the laser oscillator 10, and the light transmitted through the sheet 3 is received by the light receiving element 12.
Since the light is received by and the presence or absence of the tape 4 on the paper sheet 3 is determined based on the amount of the received light, the tape 4 is reliably attached to the paper sheet 3 without being affected by the type of the tape 4 and the paper sheet 3, for example, a fold line of a banknote. It is possible to identify the tape 4 that has been removed. Further, since no roller or the like is used, the maintenance of the roller is eliminated, and it is possible to discriminate at high speed without contact. Next, a second embodiment of the present invention will be described. The same parts as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 4 is a block diagram of an adhering matter discriminating device for a tape attached to a paper sheet. The laser light output from the laser oscillator 10 is irradiated onto the sheet 3 by the mirror 11 at a predetermined angle. The light receiving element 20 is, for example, PbSe.
An infrared detector such as the above, which receives the reflected laser light from the paper sheet 3 and outputs an electric signal according to the amount of the received light.

The discriminating device 21 has a function of discriminating the presence / absence of the tape 4 with respect to the sheet 3 based on the ratio of the respective light receiving amounts received by the respective light receiving elements 12 and 20. That is, when the laser light is applied to the tape portion, the ratio of the reflected light amount and the transmitted light amount (reflected light amount / transmitted light amount) increases.

With such a configuration, the laser beam having a wavelength of 3.4 μm output from the laser oscillator 10 is chopped by the chopper 14 and reflected by the mirror 11 to irradiate the sheet 3 at a predetermined angle. At this time, the paper sheet 3 is conveyed in the arrow (a) direction by the conveying device as in the above. Therefore, the light receiving element 12 receives the laser light transmitted through the paper sheet 3 and outputs an electric signal according to the received light amount, and the light receiving element 20 receives the reflected laser light from the paper sheet 3 and receives the received light. It outputs an electric signal according to the quantity. Then, when the laser light is irradiated to the portion where the tape 4 is adhered in the same manner as described above, the absorptance with respect to the wavelength of 3.4 μm becomes larger than that of the paper sheet 3 alone. Therefore, the output level of the light receiving element 12 of only the paper sheet 3 is as shown in FIG. 2 similarly to the above, and the output level of the light receiving element 12 of the portion to which the tape 4 is attached is the same as above.
It becomes as shown in. On the other hand, the output level of the light receiving element 20 of only the paper sheet 3 becomes as shown in FIG. 5, and the output level of the light receiving element 20 of the portion where the tape 4 is attached increases as shown in FIG. The electric signals output from the light receiving elements 12 and 20 are both sent to the discriminating device 21.

This discriminating device 21 includes the respective light receiving elements 12 and 20.
Ratio of electric signals output from each of the light receiving elements 12,
The presence / absence of the tape 4 with respect to the paper sheet 3 is determined by obtaining the ratio of the amount of received light at 20. That is, as shown in FIG.
The ratio of the amount of transmitted light to the amount of reflected light in the portion where the mark is attached becomes large, and it is determined that the tape 4 is present in the same portion.

As described above, in the second embodiment, the laser light output from the laser oscillator 10 is applied to the paper sheet 3, and the laser light transmitted through the paper sheet 3 is received by the light receiving element 12 and at the same time. Light receiving element 2 for the reflected laser light of 3
Since the light is received by 0, and the presence / absence of the tape 4 with respect to the paper sheet 3 is determined by obtaining the ratio of the received light amounts, the type of the tape 4 and the paper sheet 3, for example, a fold of a banknote, are determined as in the first embodiment. Therefore, the tape 4 attached to the paper sheet 3 can be reliably determined without being affected by. Further, since no roller or the like is used, maintenance of the roller is eliminated, and high speed discrimination can be made by non-contact. Next, a third embodiment of the present invention will be described.

FIG. 8 is a block diagram of an adhering matter discriminating device for a tape attached to a paper sheet. Infrared halogen lamp 30 is a paper sheet 3
Is arranged above the transport line. An optical chopper 31 is arranged at a position slightly below the infrared halogen lamp 30, and an interference filter 32 which transmits only light having a wavelength of 3.4 μm is arranged. Note that the interference filter 32 actually transmits light with a center wavelength of 3.4 μm.

On the other hand, a light receiving element 33 is arranged on the side facing the infrared halogen lamp 30 with the paper sheet 3 conveying line in between. The light receiving element 33 outputs an electric signal according to the amount of received light, and its output terminal is a logarithmic conversion circuit 34.
Connected to. The logarithmic conversion circuit 34 includes a light receiving element 33.
Logarithmic conversion processing is performed on the electric signal output from the computer, and its output terminal is connected to the computer 35.

The computer 35 has a logarithmic conversion circuit 34.
It has a function as a discriminating means for determining the presence or absence of the tape 4 adhering to the paper sheet 3 from the change in the transmitted light quantity by taking in the output of the above.

With this structure, the infrared light emitted from the infrared halogen lamp 30 is chopped by the optical chopper 31 and enters the interference filter 32. The interference filter 32 transmits only infrared light having a wavelength of 3.4 μm.

In this state, the paper sheet 3 is the infrared halogen lamp 3
When it reaches below 0, light with a wavelength of 3.4 μm passes through the paper sheet 3. Then, the light transmitted through the paper sheet 3 receives the light receiving element 3
It is incident on 3.

The light receiving element 33 outputs an electric signal according to the amount of light received. The logarithmic conversion circuit 34 inputs the electric signal from the light receiving element 33, performs logarithmic conversion, and sends the converted output to the computer 35.

The computer 35 has a logarithmic conversion circuit 34.
Is taken in to determine the change in the amount of transmitted light on the paper sheet 3, and the presence or absence of the tape 4 attached to the paper sheet 3 is determined from the change in the amount of transmitted light. FIG. 9 is a diagram showing a change in the amount of transmitted light obtained from the converted output of the logarithmic conversion circuit 34. The amount of transmitted light in the portion of the paper sheet 3 to which the tape 4 is attached is reduced and other tapes 4 are not attached. The amount of transmitted light in the part is averaged.

For comparison, when the electric signal output from the light receiving element 33 is directly guided to the computer 35 without passing through the logarithmic conversion circuit 34 to obtain the transmitted light amount, the transmitted light amount change shown in FIG. 10 is shown. As can be seen from this figure, the amount of transmitted light in the portion where the tape 4 is not adhered is largely changed, and in particular, the portion in which the amount of transmitted light is large indicates the portion where a watermark is formed on the paper sheet 3, for example. In other words, the watermark portion has a thickness of the paper sheet 3 which is about 20 μm thinner than the other portions, so that the amount of transmitted light becomes large. The change in the amount of transmitted light is not linear with respect to the change in the thickness of the paper sheet 3, but changes exponentially.

Therefore, it can be seen that the detection of the portion where the tape 4 adheres can be clearly determined from the change in the transmitted light amount by logarithmically converting the output of the light receiving element 33 to obtain the transmitted light amount.

As described above, in the third embodiment, the light of the wavelength 3.4 μm emitted from the infrared halogen lamp 30 and transmitted through the interference filter 32 is applied to the paper sheet 3, and the laser light transmitted through the paper sheet 3 is irradiated. Is received by the light receiving element 12, the output signal is logarithmically converted, and the presence or absence of the tape 4 is determined by obtaining the change in the amount of transmitted light of the paper sheet 3 from this logarithmically converted signal. Similarly, the area where the tape 4 is adhered and the area where the tape 4 is not adhered on the paper sheet 3 can be surely detected, and since the roller or the like is not used, maintenance of the roller is eliminated, and the contact can be discriminated at high speed. In addition, the accuracy of detecting the presence / absence of the tape 4 is high.

The present invention is not limited to the above-mentioned embodiments, but may be modified without departing from the scope of the invention. For example, as shown in FIG. 11, the opposite surface of the paper sheet 3 is irradiated with laser light, the transmitted laser light and the reflected laser light are received by the respective light receiving elements 40 and 41, and the ratio of the received light amounts is discriminated. Tape 4 that was affixed to the back side of the paper sheet 3 obtained in 21
May be configured to be determined. Further, the judgment is not limited to the tape.

[0038]

As described above in detail, according to the present invention, it is possible to provide an adhering matter discriminating apparatus which can surely discriminate the adhering matter on a sheet without making a mistake.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of an adhering matter discriminating apparatus according to the present invention.

FIG. 2 is a diagram showing an output level of a light receiving element according to a light receiving amount of only a paper sheet in the apparatus.

FIG. 3 is a diagram showing an output level of a light receiving element according to a light receiving amount of a portion having a tape in the apparatus.

FIG. 4 is a configuration diagram showing a second embodiment of an adhering matter discriminating apparatus according to the present invention.

FIG. 5 is a diagram showing an output level of a light receiving element according to a light receiving amount of only a paper sheet in the apparatus.

FIG. 6 is a diagram showing an output level of a light receiving element according to a light receiving amount with a tape in the apparatus.

FIG. 7 is a diagram showing a ratio of the amount of reflected light and the amount of transmitted light in a portion with a tape in the same device.

FIG. 8 is a configuration diagram showing a third embodiment of an adhering matter discriminating apparatus according to the present invention.

FIG. 9 is a view showing a change in transmitted light amount logarithmically converted by the apparatus.

FIG. 10 is a diagram showing changes in the amount of transmitted light when logarithmic conversion is not performed.

FIG. 11 is a configuration diagram showing a modified example of the device.

FIG. 12 is a configuration diagram of a conventional device.

FIG. 13 is a configuration diagram of a conventional device.

[Explanation of symbols]

3 ... Paper sheet, 4 ... Tape, 10 ... Laser oscillator, 11 ... Mirror, 12, 20, 30, 31, 33 ... Light receiving element, 1
3, 21 ... Discriminating device, 30 ... Infrared halogen lamp, 31
... optical chopper, 32 ... interference filter, 34 ... logarithmic conversion circuit, 35 ... computer.

Claims (3)

[Claims] 1. A light source that outputs light having an absorption wavelength that is common to an object to be inspected and an adhered object of the object to be inspected, and a light receiver that receives light output from the light source and transmitted through the object to be inspected. An adhering matter discriminating apparatus comprising: a discriminating means for discriminating the presence or absence of the adhering matter on the inspected object based on the amount of light received by the light receiver. 2. A light source that outputs light having an absorption wavelength that is common to the inspection object and the adhered material of the inspection object, and a first light receiving unit that receives the light output from the light source and transmitted through the inspection object. And a second device for receiving the reflected light of the inspection object
An adhering matter discriminating apparatus comprising: a photodetector; and a discriminating means for discriminating the presence or absence of the adhering matter with respect to the inspected object based on a ratio of respective received light amounts received by the first and second photodetectors. .. 3. A light source that outputs light having an absorption wavelength that is common to the inspection object and the adhered matter of the inspection object, and a light receiver that receives the light output from the light source and transmitted through the inspection object. An adhering matter discriminating device comprising: a logarithmic converting circuit for logarithmically converting the output signal of the photodetector; and a discriminating means for discriminating the presence or absence of the adhering substance on the inspected object based on the output of the logarithmic converting circuit. apparatus.