JP4880953B2 - Paper sheet thickness discrimination device - Google Patents

Description

  The present invention relates to a paper sheet thickness determining device that determines the thickness of paper sheets such as banknotes.

  This type of thickness discriminating apparatus includes a displacement roller and a fixed roller that is disposed opposite to the displacement roller via a paper sheet conveyance path. The paper sheet is conveyed between a displacement roller and a fixed roller, and thickness data is obtained by displacing the displacement roller by this conveyance. This thickness data is sampled at regular intervals from the front end to the rear end in the transport direction of the paper sheet, and is stored in the storage unit for each sensor.

  On the other hand, the threshold value for thickness determination is stored in the storage unit. The threshold is smoothed by statistical processing for each paper sheet type, and is generated for each type from the average value for the thickness distribution of the paper sheet.

The thickness discriminating device receives discrimination information discriminated from the characteristics of the conveyed paper sheet, and selects a thickness discrimination threshold corresponding to the discrimination information from the storage unit. Then, by comparing the selected threshold value with the thickness data of the paper sheet, it is determined whether the thickness of the paper sheet is normal or not (overlapping, foreign matter adhesion, etc.) (for example, Patent Document 1). reference.).
Japanese Unexamined Patent Publication No. Hei 4-284591

  By the way, the thickness discrimination threshold used by the thickness discrimination device is created based on an average value calculated statistically from the thickness data of the paper sheets collected for each type. When these threshold values are used, a stable thickness determination result can be obtained if the thickness of the entire paper sheet is uniform.

  However, when discriminating paper sheets that are partially different in thickness from the average thickness of paper sheets due to the printing mode and security items, the thickness is stable compared to paper sheets with uniform thickness. There was a case that the discrimination result could not be obtained.

  For example, if a judgment threshold is set that takes into account the thick part of the paper sheet, the detection performance of foreign matter attached to other than the thick part is reduced, or if the judgment threshold is created with thickness data other than a specific thick part Depending on the manufacturing variation of paper sheets, it may be determined that the thickness is abnormal based on specific thick data.

  Also, depending on which position the paper sheet is being transported, the thickness sensor may or may not scan the specific thickness portion, and the determination result may not be reproducible.

  The present invention has been made by paying attention to the above circumstances, and the object of the present invention is even when the thickness of the paper sheets is partially different or when the conveyance of the paper sheets is different. An object of the present invention is to provide a paper sheet thickness discriminating apparatus which can reliably discriminate the thickness.

In order to solve the above-mentioned problem, the invention according to claim 1 includes a conveying unit that conveys a sheet, a first reading unit that reads projection data of the sheet conveyed by the conveying unit, and the sheet A second reading unit for reading the image information of the type, a thickness detecting unit for detecting the thickness of the paper sheet conveyed by the conveying unit, and the paper sheet for each type of the paper sheet and for each conveyance state in advance. Thickness data is collected, and the average value of each section of the thickness data divided into a plurality of thickness variation points and the paper sheet conveyance direction is calculated from the collected thickness data. and control means for creating a thickness determination threshold value by adding the, and a storage means for storing the thickness determination threshold created by the control means, by said first and second reading unit Reading information of the read paper The paper sheet type and the conveyance state are detected based on the information, the thickness determination threshold value corresponding to the detection information is selected from the storage means, and the thickness detection threshold value is detected by the thickness detection means using the selected thickness determination threshold value. the thickness of the sheet was the you determine whether it is normal.
The thickness determination device of the paper sheet, wherein a call.

  According to the present invention, it is possible to reliably determine whether the thickness is good even when the thickness of the paper sheet is partially different or even when the conveyance state of the paper sheet is different.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a configuration diagram showing a paper sheet thickness determining apparatus according to an embodiment of the present invention.

  The thickness discriminating apparatus includes an apparatus main body H. In the apparatus main body H, a transport path 1 is provided as a transport unit that transports bills as paper sheets. Further, in the apparatus main body H, the first line sensor 2 as the first reading unit, the second line sensor 3 as the second reading unit, and the thickness as the thickness detecting means are arranged in the bill conveyance direction. A sensor 4 is provided. The first line sensor 2 reads projection information on the entire surface of the banknotes being conveyed, and the second line sensor 3 reads patterns and characters of the banknotes being conveyed.

  FIG. 2 is a block diagram showing the configuration of the thickness discrimination device.

The first and second line sensors 2 and 3 and the thickness sensor 4 are connected to a control unit 13 as control means via analog / digital converters 9 to 11. The control unit 13 is connected with a dictionary unit 15 and a storage unit 16 as dictionary means.

  The dictionary unit 15 stores dictionary data for prepared banknote denomination, front / back, forward / reverse, and discrimination.

  The storage unit 16 stores the thickness data of the paper sheets detected by the thickness sensor 4, and the data collected in advance for each banknote to be handled for each denomination, front and back, forward / reverse direction, and transport angle is constant. A discrimination threshold as shown in FIG. 4 created by performing the calculation is stored.

  FIG. 3 shows the thickness sensor 4.

  The thickness sensor 4 includes first to sixth sensor units 4a to 4f that are disposed at a predetermined interval in a direction orthogonal to the conveyance direction of the bills P. The first to sixth sensor parts 4a to 4f are fixed to a reference roller 6 fixed as shown in FIG. 1 and displaced by an amount corresponding to the thickness of the banknote, which is opposed to the reference roller 6 via the transport path 1. It is comprised with the movable roller 7 which does.

  Next, the bill thickness determining operation will be described.

  As shown by an arrow in FIG. 1, when a bill is inserted into the thickness discriminating apparatus and transported along the transport path 1, first, the projection information is detected by the first line sensor 2. This detection information is transmitted to the control unit 13 and collected and stored for each line as projection data. The control unit 13 calculates, for example, the center position CP and the inclination angle θ of the banknote to be transported as shown in FIG. 2 based on the stored projection data of the transported banknote.

  The banknotes that have passed through the first line sensor 2 are conveyed to the second line sensor 3, and the pattern and character data are read out. The characteristic data of the banknote surface is transmitted to the control unit 13 and collected and stored for each line.

  When the bill passes through the second line sensor 3 and the data reading of the entire surface is completed, the control unit 13 stores the stored data and the dictionary data for the denomination, front / back and forward / reverse discrimination prepared in the dictionary unit 15 in advance. The banknote denomination, front / back, and forward / reverse are discriminated.

  The bill that has passed through the second line sensor 3 is conveyed to the thickness sensor 4 and the thickness thereof is detected. The detected thickness data is transmitted to the control unit 13. The control unit 13 samples the transmitted thickness data with a resolution at which a change in bill thickness can be sufficiently identified.

  For example, as shown in FIG. 6, the outputs from the sensor units 4 a to 4 f are sampled in units of 1 mm for each of the sensor units 4 a to 4 f of the thickness sensor 4 and stored in the storage unit 16.

  When it is confirmed that the bill has passed through the thickness sensor 4, the control unit 13 determines the thickness of the conveyed bill from the thickness sensor data held in the storage unit 16.

  In the thickness determination process, a threshold value for identifying whether the banknote thickness data is normal or abnormal is used. The relationship between the threshold value used in the determination process and the process is as follows.

  In the case of thickness lower limit threshold> conveyance ticket thickness data, it is assumed that the thickness is not more than the lower limit and the thickness is abnormal.

  In the case of thickness upper limit threshold <conveyance ticket thickness data, the thickness is equal to or greater than the upper limit and the thickness is abnormal.

  Next, a criterion for creating a determination threshold when performing thickness determination will be described.

  For example, as shown in FIG. 3, when a partially thick banknote P is transported by printing or mounting a genuine item, the partially thick feature existing on the banknote P changes as follows depending on the transport position. To do. That is, when the bill is conveyed along the position A, the output of the sensor unit 4a changes as shown in FIG. 7, and when the bill is conveyed along the position B, as shown in FIG. The output of the sensor unit 4a changes.

  The same applies to the case where the bill is conveyed at an angle. At position A, the output of the sensor unit 4a changes as shown in FIG.

  Furthermore, when a banknote is conveyed along the position A in a state where the thick part is opposite, the thick part of the banknote is detected by the sensor unit 4f instead of the sensor unit 4a.

  Therefore, in order to accurately read a thick portion of a banknote and perform the thickness determination process, it is necessary to set a determination threshold for thickness data that changes depending on the denomination, transport direction, and transport angle of the banknote.

  Therefore, for all banknotes handled by the banknote handling apparatus, a predetermined calculation is performed on the data collected in advance for each denomination, front / back, forward / reverse direction, and transport angle, and a thickness determination threshold value is created, and the created threshold value is stored. Store in unit 16.

  For example, the thickness data shown in FIG. 7 obtained from the bill thickness sensor 4a conveyed along the position A in FIG. , Section b, and section c.

  Similarly, as shown in FIG. 9, the banknote P conveyed at an angle θ can be divided into three sections a, b, and c according to the thickness.

  The determination threshold value is calculated from an average value of the thickness variation point and each section from a large amount of banknote thickness data collected according to each denomination, front / back / forward, transfer position, and transfer angle, and the overlap determination threshold is a constant K1. The discrimination threshold for detecting foreign matter adhesion that is thinner than the bill thickness is calculated by a constant K2.

  The relationship between the bill thickness data obtained from the thickness sensor 4 and the discrimination threshold is as shown in FIG.

  The thickness determination threshold value is stored in the storage unit 16 as shown in FIG. 4 for each denomination, front / back, forward / reverse, transport position, and transport angle of the banknote as described above. The stored thickness determination threshold value is referred to when the control unit 13 determines the thickness.

  When this determination threshold value is mounted on the thickness determination device, for example, when foreign matter determination is performed on the tape-bonded bill shown in FIG. 11, the foreign matter detection threshold value corresponding to the thick portion and thin portion of the bill is set.

  Therefore, in the section b where the tape is attached, the thickness of the original banknote is large, so the foreign matter detection threshold is also high. In the section c, the thickness of the original banknote is small, so the threshold is low.

  That is, since the same reference threshold is set in both sections with respect to the thickness of the banknote itself, the thickness exceeds the banknote thickness upper limit threshold in the above-described determination logic without being affected by the thickness fluctuation peculiar to the banknote. In this way, it is possible to detect the tape attached on the banknote.

  As described above, for all the paper sheets to be handled, the storage unit 16 stores the threshold value created by collecting thickness data in advance for each type and transport state, and performing a certain calculation on the collected thickness data. The threshold corresponding to the detection information of the banknote detected based on the read information of the first and second line sensors 2 and 3 is selected from the storage unit 16, and the thickness of the banknote is determined based on the selected threshold. Judgment of good or bad. Therefore, even when a foreign object adheres to a thin portion of the bill itself or when the position or angle of the bill scanned by the line sensors 2 and 3 is changed, it is possible to determine whether the thickness is good or bad. it can.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, you may delete some components from all the components shown by embodiment mentioned above. Furthermore, you may combine the component covering different embodiment suitably.

The block diagram which shows the thickness discrimination | determination apparatus of the banknote which is one embodiment of this invention. The block diagram which shows the structure of the thickness discrimination | determination apparatus of the banknote. The top view which shows the state of the banknote conveyed along the conveyance path of the thickness discrimination | determination apparatus. The figure which shows the threshold value stored in the memory | storage part. The top view which shows the banknote from which thickness is detected by the same thickness sensor. The graph which shows the thickness data memorize | stored in the memory | storage part. The figure which shows the change of the thickness data detected by the same thickness sensor. The figure which shows the change of the thickness data detected by the same thickness sensor. The figure which shows the change of the thickness data detected by the same thickness sensor. The graph figure which shows the same overlap determination threshold value and a foreign material determination threshold value. The figure which shows the state by which the banknote on which the tape was stuck was determined by the same foreign material determination threshold value.

Explanation of symbols

     P ... bills (paper sheets), 1 ... conveying path (conveying means), 2 ... first line sensor (first reading unit / reading means), 3 ... second line sensor (second reading unit / Reading unit), 4... Thickness sensor (thickness detection unit), 13... Control unit (discrimination unit), 15.

Claims (3)

Conveying means for conveying paper sheets;
A first reading unit that reads projection data of a sheet conveyed by the conveying unit;
A second reading unit for reading image information of the paper sheet;
A thickness detecting means for detecting the thickness of the paper sheet conveyed by the conveying means;
The thickness data of the paper sheets is collected in advance for each type of the paper sheets and for each transport state, and the thickness variation point and the plurality of the paper sheets are divided along the transport direction of the paper sheets from the collected thickness data. A control means for calculating an average value of each section of the thickness data and adding a constant to the calculated value to create a thickness determination threshold ;
Storage means for storing a thickness determination threshold created by the control means ,
The control means detects the type and conveyance state of the paper sheet based on the read information of the paper sheet read by the first and second reading units, and the thickness determination threshold corresponding to the detection information It was selected from the memory means, the sheet, wherein the benzalkonium determine whether the thickness of the paper sheet detected by the thickness detection unit using the selected thickness determined threshold is normal Thickness discrimination device. Having a dictionary part for storing dictionary data for discriminating the type, front and back, and forward / reverse of the paper sheet,
The first reading unit is a first line sensor,
The second reading unit is a second line sensor,
The control means stores the data read by the first and second line sensors for each line , compares the stored data with the dictionary data of the dictionary unit, and the state of conveyance of the paper sheet and its type The sheet thickness discriminating apparatus according to claim 1 , further comprising: discriminating between front, back, and forward / reverse . A value obtained by adding a constant K1 to the average value of each section of the thickness data calculated by the control means is used as a threshold for discriminating overlap of paper sheets, and a value obtained by adding the constant K2 to the average value is determined as foreign matter adhesion. 3. The paper sheet thickness discriminating apparatus according to claim 1 , wherein a threshold value for the paper sheet is used.

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