JPH07101465B2 - Paper sheet defect detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention detects a defect such as a hole or stain in a paper sheet such as a banknote and determines the mode of the defect such as the size and position of the defect. The present invention relates to a leaf defect detection device, and more particularly to a device having high reliability of the detection operation and high accuracy of the determination operation result.

[Conventional technology]

FIG. 11 is a main part configuration diagram of a banknote defect detection device 6 that is conventionally used for automatically discriminating banknotes. In the figure, 1 is a banknote 2 parallel to the paper surface of the banknote. The banknote transport path 3 serving as a transport means configured to transport in the P direction as a direction is arranged in a line along the width direction of the transport path 1 and is spatially fixed by means not shown. In this case, each photodetector 3 is composed of a single projector and a light receiver which are arranged so as to face each other with the banknote 2 sandwiched in the thickness direction. 3a is a light reception signal output from this light receiver, and 4 is all the light reception signals 3a output from all of the photodetectors 3, and a predetermined signal processing is performed on these input signals to the banknote 2. The signal processing unit is configured to detect the presence or absence of the existing defect 5 and determine the form of the defect 5 such as the position and size of the defect 5.

[Problems to be Solved by the Invention]

Since the defect detection device 6 is configured as described above, the defect detection is performed by the photodetector 3 over the entire length of the banknote 2 in the P direction as the banknote 2 is transported in the P direction by the transport path 1. However, in this case, all the photodetectors 3 have a discrete arrangement in which there is an appropriately determined distance d between the adjacent detectors 3 and 3, so that Both detectors with defect 5 next to each other during transportation
If the defect 5 is of a size that cannot be detected by either of these detectors 3 and 3 when passing between 3 and 3,
The signal processing unit 4 determines that there is no defect even though the banknote 2 actually has the defect 5, and
In this case, even if one of the detectors 3 detects the defect 5, the signal processing unit 4 detects the position of the defect 5 detected by the level change of the output signal 3a of the detector 3 and the partial position of the defect 5. The length in the P direction can be determined, but the spread of the defect 5 in the direction perpendicular to the P direction cannot be determined. That is, since the detectors 3 are discretely arranged in the above-described conventional defect detection device 6, there is a problem that the operation accuracy such as the detection accuracy for the defect 5 and the determination accuracy for the size of the defect 5 is low. is there.

An object of the present invention is to perform defect detection over the entire surface of a paper sheet so that the reliability of the detection operation for the defect in the paper sheet is high and the accuracy of the result of the determination operation for the position and size of the defect is high. To obtain a high-quality sheet defect detection device.

[Means for Solving the Problems]

In order to achieve the above object, according to the present invention, a conveying means for conveying a paper sheet in one direction parallel to the paper surface of the paper sheet, and a paper sheet conveying for conveying the paper sheet of the conveying means. A horizontal scanning signal generator that outputs a horizontal scanning signal in synchronism with an operation, a vertical scanning signal generator that outputs a vertical scanning signal in synchronism with the paper sheet conveying operation, and the paper conveyed by the conveying means. A light-transmissive optical detection unit that scans the leaves with light in a direction intersecting the one direction according to the input horizontal scanning signal and outputs a light reception signal according to the scanning result; The unit storage areas are arranged in a two-dimensional manner corresponding to the paper surface of the paper sheets, and the arrangement configuration of the unit storage areas formed in the image memory shape with respect to the paper surface of the paper sheets is convenient. A first storage part and a second storage part each having one The horizontal scanning signal, the vertical scanning signal, and the light receiving signal are input, and the level of the light receiving signal is binaryly discriminated based on a first threshold value, and the discrimination result is the first storage unit. Of the horizontal scanning signal and the vertical scanning signal in the storage area, the level of the light receiving signal is stored in the unit storage area having a designated address number specified by the content of the vertical scanning signal and the level of the light receiving signal is higher than the first threshold value. Binary discrimination is performed based on the second threshold value having a low level, and the discrimination result is stored in the unit storage area having the same address number as the designated address number in the storage area of the second storage section. A data storage unit; and a determination unit that determines a mode of a defect in the paper sheet based on the stored contents of the storage regions in each of the first storage unit and the second storage unit, The optical detection unit, the horizontal scanning signal generation unit, and the optical scanning unit so that the optical detection unit scans the paper surface of the paper sheet conveyed by the conveying unit without overlapping with the light. The sheet defect detecting device is configured so that the conveying means is configured.

[Action]

With the above configuration, the presence or absence of a defect is detected over the entire surface of the paper sheet by the optical detecting unit along with the paper sheet conveying operation in the conveying unit.
Depending on the stored contents of the first storage unit, there are no paper sheets or the paper sheets have an abnormally thin thickness, and the position and extent of the defect in the paper sheets in a state in which light is easily transmitted therethrough. In the paper sheet, the paper sheet is soiled or the paper sheet is abnormally thick depending on the stored content of the second storage unit. Since it is possible to determine the position and spread of the defect in a state where it becomes difficult to transmit light, the determination unit can determine the reliability of detection of the defect of the paper sheet and the determination result for the position or size of the defect. It is possible to obtain a paper sheet defect detection apparatus with high accuracy.

〔Example〕

FIG. 1 is a block diagram of an embodiment of the present invention. In this figure, 7 is a conveyor belt for carrying the banknotes 2, 8 is a belt for driving the banknotes 2 carried on the belt 7 by the belt so as to carry the banknotes 2 at a predetermined constant speed, and A belt driving device that outputs a synchronizing signal 8a synchronized with the bill transporting operation, 9 is a transporting unit corresponding to the above-described bill transporting path 1 including the belt 7 and the driving device 8, and 10 is a synchronizing signal 8a. Is a horizontal scanning signal generator that immediately outputs the horizontal scanning signal 10a, and 11 is a vertical scanning signal generator that immediately outputs the vertical scanning signal 11a when the synchronization signal 8a is input. .

Reference numeral 12 denotes a light projecting portion 13 in which a large number of minute light projecting elements 13a are arranged in a line in a direction perpendicular to the plane of the drawing and are formed in a band shape.
A light-transmissive optical detection section including a large number of minute light-receiving elements 14a arranged in a line in a direction perpendicular to the plane of the drawing and formed in a strip shape, and in this case, a light-projecting section 13 As shown in the figure, the light receiving section 14 and the light receiving section 14 are arranged so as to face each other with the belt 7 interposed therebetween, and are fixed in the space by means not shown. Of course, in this case, the light projecting section 13 is provided by the belt 7. The bills 2 are arranged so as not to obstruct the conveyance of the bills 2, and the belt 7 is configured to transmit the light emitted from the light projecting element 13a. And again, in this case
The light projecting portion 13 and the light receiving portion 14 are formed and arranged so that the light emitting surface of the light projecting element 13a and the light incident surface of the light receiving element 14a face each other through the belt 7 in a one-to-one manner. Projector
When the horizontal scanning signal 10a is input, the signal 13a extends from the light projecting element 13a on the one end side of the light projecting section 13 to the light projecting element 13a on the other end side of the light projecting section 13 by the signal 10a. Are sequentially emitted one by one, and the light is used to scan the belt 7 or the banknote 2 once in a linear band shape. Each dimension and arrangement of the light projecting unit 13 and the light receiving unit 14 and the transportation so that the entire area of the upper surface of the banknote 2 that is perpendicular to the P arrow direction is always illuminated by the emitted light of the element 13a. P of the portion on which the banknote 2 is placed in the means 9
The width dimension in the direction perpendicular to the arrow direction is determined. Then, the horizontal scanning signal generator 10 outputs the horizontal scanning signal 10a as the conveying means 9 conveys the banknote 2, so that the upper surface of the banknote 2 is projected by the light projecting element 13a. The conveying means 9, the horizontal scanning signal generating section 10 and the light projecting section are arranged so that they are irradiated with the emitted light without overlapping.
13 and are composed.

Reference numeral 14b designates a light receiving signal in which output signals of all the light receiving elements 14a constituting the light receiving portion 14 are integrated, and 15 receives the light receiving signal 14b, and the level V of this signal 14b is used as a built-in first threshold value. The comparator 16 which outputs a binary signal 15a whose value is "1" when VV ₁ and "0" when V <V ₁ is discriminated with reference to the voltage V ₁ of When the light reception signal 14b is input and the level V of this signal 14b is determined with reference to the voltage V ₂ as the second built-in threshold value, if it is VV ₂ , the value becomes "1" and V> V ₂ a comparator which is adapted there the value outputs a binary signal 16a becomes "1", this case, V _1, V ₂ are set such that V _1> V _2. Note that, in FIG. 1, each element 14a constituting the light receiving section 14 is configured to output an output signal that raises the level V of the light receiving signal 14b in proportion to an increase in the amount of light incident on the element 14a. In this case, the received light signal 14b
However, in response to the above-described optical scanning by the light projecting unit 13, the light receiving element 14
It is obvious, of course, that the time-series signal is composed of individual signals output from a.

Each of 171, 172 is the same number of unit storage areas 19 as the pixel 18 corresponding to each of a large number of rectangular pixels 18 constituting the paper surface of the banknote 2, which are virtual on the paper surface of the banknote 2 as shown in FIG. Are arranged two-dimensionally so as to have the same arrangement as the arrangement of the pixels 18 on the paper surface of the banknote 2, and are formed in the image memory shape for the paper surface of the banknote 2 as shown in FIG. In the storage area, the rectangular pixel 18 is a minute area of the banknote 2 which is equal to the area of the banknote 2 illuminated by one light emission of the one light projecting element 13a described above. Then, in this case, a unique address number is attached to each of the above-mentioned unit storage areas 19, although not shown.

20 has a storage area 171 built therein and has an address signal 22a.
And the comparator output signal 15a are input, and when the address signal 22a is input, the value of the binary signal 15a at that time is read and the storage area having the address number represented by the address signal 22a is read. Unit storage area 1 in 171
The first storage unit, which is adapted to be stored in 9, 21 has a storage area 172
Is incorporated and the address signal 22a and the comparator output signal 16a are input, and when the address signal 22a is input, the value of the binary signal 16a at that time is read and this value is set to the address signal 22a. The second storage unit 22 is adapted to store the data in the unit storage area 19 of the storage area 172 having the address number represented by, and the horizontal scanning signal 10a and the vertical scanning signal 11a.
Is an input signal, and is an address signal generator that outputs an address signal 22a representing the address number of the unit storage area 19 in the storage area 171 or 172 determined by both input signals. In this case, the address signal 22a represents The unit storage area 19 having the address number is a unit storage corresponding to the pixel 18 in the banknote 2 illuminated by the light projecting element 13a selected by the horizontal scanning signal 10a when the address signal generator 22 generates the address signal 22a. It has become an area. Reference numeral 23 is a data storage unit including the above-mentioned comparators 15 and 16, storage units 20 and 21, and an address signal generation unit 22.

In FIG. 1, since each part is configured as described above, when the bill 2 has the holes 24 extending over four pixels 18 as shown in FIG. 4, it is conveyed by the conveying means 9. When the light projecting unit 13 optically scans the banknote 2 that is to be used, the light emitted from the light projecting element 13a easily reaches the light receiving element 14a only in the hole 24.
There are four unit storage areas 1 in the storage area 171 of the first storage section 20 corresponding to each pixel 18 of the banknote 2
The signal value "1" is stored in 9 as shown in FIG.
Moreover, the signal value “0” is stored in all of the remaining unit storage areas 19 in the storage area 171 and the unit storage areas 19 in the storage area 172 of the second storage unit 21. However, in FIG. 5, “0” is omitted for convenience of description. And then again
In FIG. 1, since each part is configured as described above, if the banknote 2 has black stains over the four convenient pixels 18 as shown in FIG. 6, the banknote 2 is thrown this time. Most of the light emitted from the light projecting element 13a is shielded only at the portion of the dirt 25 when it is optically scanned by the light unit 13.
The second corresponding to each pixel 18 of the banknote 2 in which 5 is present
The signal value "1" is stored in the four convenient unit storage areas 19 in the storage area 172 of the storage unit 21 as shown in FIG. 7, and the remaining unit storage areas 19 and the first storage areas in the storage area 172 are stored. Unit storage area 19 in storage area 171 of section 20
The signal value "0" is stored in all of the. Then, the 7th
Also in the figure, "0" is omitted.

Then, further, in the case of FIG. 1, it is clear from the above-mentioned place that there is a state 26 in which the bill 2 as shown in FIG. Storage area 17
As shown in FIG. 9, 1 stores the signal value "1" in all the unit storage areas 19 in the corner portion C of the storage area 171 corresponding to the corner portion A where the banknote 2 is not present in FIG. Further, in the storage area 172, as shown in FIG. 10, all the unit storage areas 19 in the portion D of the storage area 172 corresponding to the portion B in which the banknote 2 is folded in FIG. Will be remembered. Then, the ninth
In FIG. 10 and FIG. 10, "0" is stored in all the unit storage areas 19 in which "1" is not stored.

27 in FIG. 1 reads "1" by reading the contents stored in the storage areas 171 and 172 as shown in FIG. 5 or FIG.
The location of the area 19 in which
The position, spread, shape, etc. of 25 can be specified, and
Area 17 where "1" is stored as shown in Fig. 10
The storage contents of 1,172 are read, and the arrangement state of the area portions C and D and the unit storage area 19 in each of the portions C and D are read.
The determination unit that determines that the folded state 26 exists in the banknote 2 based on the respective numbers of the numbers, and then specifies the position, size, shape, etc. of the folded 26 from the position of the region 19 and the even number in the part C or D. Therefore, in other words, the determination unit 27, in other words, based on the stored contents of the storage areas 171 and 172 in the first and second storage units 20 and 21, respectively, the hole 24, the stain 25, the fold 26, etc. in the banknote 2. It means that the mode of defect 5 is determined. 28 in Fig. 1
Is a defect detecting device for a banknote, which comprises the respective units shown in FIG.

Since the defect detecting device 28 is configured as described above, it is clear that the paper surface of the bill 2 conveyed by the conveying means 9 is always optically scanned by the optical detecting section 12 over the entire surface thereof. Therefore, according to the configuration of the defect detection device 28, the detection failure of the defect 5 such as the hole 24 and the dirt 25 existing in the banknote 2 does not occur, so the detection device 28 is a defect detection device with high defect detection accuracy. It turns out that. Then, since the defect detection device 28 is configured as described above, the defect 5 in the banknote 2 has the signal value "1" in the storage areas 171 and 172 formed in the image memory shape with respect to the paper surface of the banknote 2. Appearing as a set, it is clear that the form of this set becomes a form substantially similar to the form of defect 5. Therefore, according to the configuration of the detection device 28, the region 171,
Since the position, size, shape, etc. of the defect 5 in the banknote 2 can be known almost accurately from the collection mode of “1” in 172, the detection device 28 is also a defect detection device with high determination accuracy for the mode of the defect 5. There is.

In the above-described embodiment, the light projecting unit 13 and the light receiving unit 14 are all formed in a strip shape by arranging the elements 13a, 14a in a line, but in the present invention, the light projecting unit 13, the light receiving unit. 14
One of the two elements may be formed as a strip-shaped element, and in the above-described embodiment, the light projecting elements 13a forming the light projecting section 13 are sequentially caused to emit light so that the banknote 2 is optically scanned. However, in the present invention, the bill 2 may be scanned with one light beam. And then,
Although the optical scanning by the optical detection unit 12 is performed perpendicularly to the P direction in the above-described embodiment, the optical scanning direction may be inclined with respect to the P direction in the present invention.

〔The invention's effect〕

As described above, according to the present invention, the conveying means for conveying the paper sheet in one direction parallel to the paper surface of the paper sheet and the paper sheet conveying operation for conveying the paper sheet by the conveying means are synchronized with each other. A horizontal scanning signal generator for outputting a horizontal scanning signal, a vertical scanning signal generator for outputting a vertical scanning signal in synchronism with the paper sheet conveying operation, and a paper sheet conveyed by the conveying means. A light-transmissive optical detection unit that scans with light in a direction intersecting with the one direction according to a horizontal scanning signal and outputs a light receiving signal according to the scanning result; A first storage having two storage areas which are arranged in a two-dimensional manner corresponding to the paper surface of the leaves and have the same arrangement configuration of unit storage areas formed in an image memory shape with respect to the paper surface of the paper sheets. Section and a second storage section are provided, and a horizontal scanning signal and a vertical scanning signal are provided. The received light signal is inputted, and the level of the received light signal is binaryly discriminated based on the first threshold value, and the discrimination result is the contents of the horizontal scanning signal and the vertical scanning signal in the storage area of the first storage section. Is stored in a unit storage area having a designated address number designated by and the level of the received light signal is binarized based on a second threshold value lower than the first threshold value. This determination result is the second
A paper sheet based on a data storage unit that stores a unit storage area having the same address number as the specified address number in the storage area of the storage unit and the stored contents of the storage areas in each of the first storage unit and the second storage unit. And a determination unit that determines a mode of a defect in the paper, and the optical detection unit optically detects the paper surface of the paper sheet conveyed by the conveying unit so as to scan the entire surface of the paper sheet with the light without overlapping. The sheet defect detecting apparatus is configured so that the sheet scanning unit, the horizontal scanning signal generating unit, and the transporting unit are configured.

Therefore, with the above configuration, the presence or absence of a defect is detected over the entire surface of the paper sheet by the optical detection unit along with the paper sheet conveyance operation by the conveyance unit, and the first storage unit is also provided. Depending on the stored contents of, the paper sheet does not exist or the paper sheet is abnormally thin. The position and the extent of the defect in the paper sheet in the state where the light can be easily transmitted can be determined by the determination unit, and further, the storage content of the second storage unit may stain the paper sheet or Since the position and the extent of the defect in the paper sheet in which the thickness of the paper sheet is abnormally thick and in which it is difficult to transmit light in the paper sheet can be determined by the determination unit, the present invention provides a paper sheet. There is an effect that it is possible to obtain a paper sheet defect detection apparatus which has a high reliability of detection of a defect of a leaf and an accurate determination result of the position and size of the defect.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention, and FIGS. 2 to 10 are operation explanatory diagrams different from each other for explaining the operation of the embodiment of the present invention shown in FIG. FIG. 1 is a block diagram of a main part of a conventional bill defect detecting device. 1 ... Banknote transport path, 2 ... Banknote, 3 ... Photodetector, 3a, 1
4b ... Receiving signal, 5 ... Defect, 6,28 ... Banknote defect detecting device, 9 ... Conveying means, 10 ... Horizontal scanning signal generating section, 10a ...
... horizontal scanning signal, 11 ... vertical scanning signal generation section, 11a ... vertical scanning signal, 12 ... optical detection section, 19 ... unit storage area, 20
...... First storage unit, 21 ...... Second storage unit, 23 ...... Data storage unit, 27 ...... Determination unit, 171,172 ...... Storage area, V ...... Receiving signal level, V ₁ ...... First threshold value Value, V ₂ ... second threshold value.

Claims (1)

[Claims] 1. A horizontal scanning signal in synchronism with a conveying means for conveying a sheet in one direction parallel to the paper surface of the sheet and a sheet conveying operation for conveying the sheet by the conveying means. A horizontal scanning signal generation unit that outputs a vertical scanning signal generation unit that outputs a vertical scanning signal in synchronization with the paper sheet conveying operation, and a horizontal scanning signal input unit that inputs the paper sheets conveyed by the conveying unit. A light-transmissive optical detector for scanning with light in a direction intersecting with the one direction according to a scanning signal and outputting a light receiving signal according to the scanning result, and a plurality of unit storage areas for the paper sheets. Storage unit having two storage areas, which are arranged two-dimensionally corresponding to the paper surface of the sheet and have the same arrangement configuration of the unit storage areas formed in the image memory shape with respect to the paper surface of the paper sheets. And a second storage section are provided, and the horizontal scanning signal and the vertical scanning are provided. Signal and the received light signal are input, and the level of the received light signal is binaryly discriminated based on a first threshold value, and the discrimination result is subjected to the horizontal scanning in the storage area of the first storage unit. The second threshold value is stored in the unit storage area having a designated address number designated by the content of the signal and the content of the vertical scanning signal and the level of the light receiving signal is lower than the first threshold value. And a data storage unit that stores the determination result in the unit storage area having the same address number as the designated address number in the storage area of the second storage unit, A storage unit and a determination unit that determines a mode of a defect in the paper sheet based on each storage content of the storage region in each of the second storage unit,
The optical detection unit and the horizontal scanning signal generation unit so that the optical detection unit scans the paper surface of the paper sheet conveyed by the conveyance unit without overlapping with the light with the light. A paper sheet defect detection device, characterized in that the transport means is configured.