Paper sheet identification device, paper sheet processing device, and paper sheet identification method

Abstract

To provide a paper sheet identification device, a paper sheet processing device, and a paper sheet identification method capable of detecting abnormalities in terms of shape when a paper sheet is deformed.SOLUTION: A paper sheet identification device is provided with a deformation determination unit that performs, in an optical image of a paper sheet, at least one of the following comparison processes: a first comparison process that compares the slopes of two areas on the same edge of a paper sheet at different positions among four areas on the edge, and a second comparison process that compares the slopes of two areas on two opposing edges, and determines the paper sheet to be a deformed paper sheet when the slopes do not match in either of the comparison processes.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a paper sheet discrimination device, a paper sheet processing device, and a paper sheet discrimination method.

Background Art

[0002] As a processing device for processing paper sheets such as banknotes (banknotes), gift certificates, checks, and securities, there is a device having a function of determining normal or damaged, and the degree of damage of the paper sheets is recognized by detecting an abnormal state of the shape of the paper sheets.

[0003] Patent Document 1 discloses a paper sheet discrimination device and a paper sheet virtual frame generation method characterized by generating a virtual frame from the four corner coordinates of a detected medium.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Paper sheets include those made of paper and those made of polymer (resin-based). When the material is paper, the periphery of the paper sheet often becomes a missing state, but when the material is polymer, deformation due to heat often occurs.

[0006] With the technology described in Patent Document 1, it is possible to detect a missing part around the medium, but it is difficult to detect deformation of the medium, which often occurs when the material of the paper sheet is polymer. Also, it is difficult to detect a paper sheet that is folded and deformed on an optical image.

[0007] The present invention has been made in view of the above situation, and an object thereof is to provide a paper sheet discrimination device, a paper sheet processing device, and a paper sheet discrimination method capable of detecting an abnormal shape when the paper sheet is deformed.

Means for Solving the Problem

[0008] In order to solve the above-described problems and achieve the object, (1) the paper sheet discrimination device of the present disclosure performs at least one of a first comparison process of comparing the slopes of two regions at different positions on the same peripheral side among the regions on the four peripheral sides of the paper sheet in the optical image of the paper sheet, and a second comparison process of comparing the slopes of two regions on two opposing peripheral sides, and includes a deformation determination unit that determines the paper sheet as a deformed paper sheet when the slopes do not match in any of the comparison processes.

[0009] (2) In the paper sheet discrimination device according to (1) above, the deformation determination unit may perform at least the first comparison process.

[0010] (3) In the paper sheet discrimination device according to (1) or (2) above, the deformation determination unit may perform at least the second comparison process.

[0011] (4) In the paper sheet discrimination device according to any one of (1) to (3) above, the four peripheral sides have two opposing long sides and two opposing short sides, and in the deformation determination unit, as the first comparison process, the slopes of two regions at different positions on the same long side may be compared.

[0012] (5) In the paper sheet discrimination device according to any one of (1) to (4) above, the four peripheral sides have two opposing long sides and two opposing short sides, and in the deformation determination unit, as the second comparison process, the slopes of two regions at positions where at least a part does not face each other on two opposing long sides may be compared.

[0013] (6) In the paper sheet discrimination device according to any one of (1) to (5) above, the four peripheral sides have two opposing long sides and two opposing short sides, and in the deformation determination unit, as the second comparison process, the slopes of two opposing short sides may be compared.

[0014] (7) In the paper sheet discrimination device according to any one of (1) to (6) above, the paper sheet is a polymer banknote, and the deformed paper sheet may be a polymer banknote in which deformation has occurred.

[0015] (8) In the paper sheet discrimination device according to any one of (1) to (7) above, the optical image of the paper sheet may be an infrared image.

[0016] (9) The paper sheet processing device of the present disclosure includes the paper sheet discrimination device according to any one of (1) to (8) above.

[0017] (10) In the paper sheet discrimination method of the present disclosure, in the optical image of the paper sheet, among the regions on the four peripheral sides of the paper sheet, a first comparison process of comparing the slopes of two regions at different positions on the same peripheral side, and a second comparison process of comparing the slopes of two regions on two opposing peripheral sides are performed. When the slopes do not match in any of the comparison processes, a deformation determination step of determining the paper sheet as a deformed paper sheet is performed.

Advantages of the Invention

[0018] According to the present disclosure, it is possible to provide a paper sheet discrimination device, a paper sheet processing device, and a paper sheet discrimination method that can detect an abnormality in the shape when the paper sheet is deformed.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0020] Hereinafter, with reference to the drawings, embodiments of a paper sheet identification apparatus, a paper sheet processing apparatus, and a paper sheet identification method according to the present disclosure will be described in detail. As the paper sheets targeted by the present disclosure, various paper sheets such as banknotes, checks, gift certificates, promissory notes, documents, securities, card-shaped media, etc. are applicable.

[0021] Note that the material of the paper sheets in this specification is not particularly limited and includes those made of paper or polymer (resin). Further, the banknotes in this specification include paper banknotes made of paper and polymer banknotes made of polymer.

[0022] In the following description, the same reference numerals are commonly and appropriately used for the same parts or parts having the same functions among different drawings, and the repeated description thereof is appropriately omitted.

[0023] (Embodiment 1) Using FIG. 1, the configuration of the paper sheet discrimination device according to this embodiment will be described. FIG. 1 is a block diagram for explaining an example of the configuration of the paper sheet discrimination device according to Embodiment 1.

[0024] As shown in FIG. 1, the paper sheet discrimination device 1 according to this embodiment is a device that discriminates banknotes as paper sheets, and includes a deformation determination unit 10.

[0025] Note that the paper sheet discrimination device 1 may also include a storage unit composed of other storage devices such as a semiconductor memory (RAM or ROM) and a hard disk.

[0026] As shown in FIG. 1, the deformation determination unit 10 has a first comparison processing unit 11 and a second comparison processing unit 12.

[0027] The deformation determination unit 10 is configured as a computer system including a CPU (Central Processing Unit) and various hardware (for example, FPGA (Field Programmable Gate Array)) controlled by the CPU. The deformation determination unit 10 realizes various processes by executing a predetermined software program in the CPU.

[0028] An optical image of the paper sheet is introduced into the deformation determination unit 10. The method for acquiring the optical image of the paper sheet and the type of the optical image are not particularly limited, and the optical image may be either a transmission image that passes through the paper sheet or a reflection image that is reflected by the paper sheet. Also, both the transmission image and the reflection image may be used. The optical image may be an infrared image. The infrared image is image data obtained by irradiating the paper sheet with infrared light and detecting the infrared light that has passed through or been reflected by the paper sheet. In the deformation determination unit, preprocessing such as edge detection may be performed on the optical image prior to the comparison processing to detect the contour shape of the paper sheet (for example, each coordinate corresponding to the contour).

[0029] The deformation determination unit 10 performs at least one of the first comparison process and the second comparison process to determine whether the paper sheet is a deformed paper sheet.

[0030] Next, with reference to FIG. 2, an example of the operation of the paper sheet discrimination apparatus 1 according to the present embodiment will be described. FIG. 2 is a flowchart for explaining an example of the operation of the paper sheet discrimination apparatus according to Embodiment 1.

[0031] As shown in FIG. 2, first, a process of introducing an optical image of the paper sheet into the deformation determination unit is executed (step S11).

[0032] The inclination of each region in the optical image introduced into the deformation determination unit is determined (step S12). How to set the regions on the four peripheral sides of the paper sheet can be set in advance, and specific examples of the method for setting the regions will be described later.

[0033] Next, the first comparison processing unit 11 performs a first comparison process of comparing the inclinations of two regions located at different positions on the same peripheral side among the regions on the four peripheral sides of the paper sheet (step S13). The first comparison processing unit 11 determines whether the inclinations of the two regions match based on an inclination threshold for determining that the "inclinations do not match". In step S13, if there is a region where the "inclinations do not match" (step S13, Yes), it may be determined that the paper sheet is a deformed paper sheet, and the operation of the paper sheet discrimination apparatus 1 may end (step S14).

[0034] In step S13, if there is no region where the "inclinations do not match" (step S13, No), the second comparison processing unit 12 performs a second comparison process of comparing the inclinations of two regions on two opposing peripheral sides (step S15). The second comparison processing unit 12 determines whether the inclinations of the two regions match based on an inclination threshold for determining that the "inclinations do not match". In step S15, if there is an area where "the slopes do not match" (step S15, Yes), it may be determined that the paper sheets are deformed paper sheets, and the operation of the paper sheet identification device 1 may end (step S16).

[0035] In step S15, if there is no area where "the slopes do not match" (step S15, No), it may be determined that the paper sheets are normal paper sheets, and the operation of the paper sheet identification device 1 may end (step S17).

[0036] Note that in the above example, a flowchart showing that the first comparison process is performed and then the second comparison process is shown. However, the second comparison process may be performed first and then the first comparison process. Also, either one of the first comparison process or the second comparison process may be performed.

[0037] FIG. 3 is a schematic plan view showing an example of non-deformed paper sheets. FIG. 3 shows normal paper sheets 20 which are non-deformed paper sheets. FIG. 4 is a schematic plan view schematically showing an example of deformed paper sheets. FIG. 4 shows deformed paper sheets 30 which are deformed paper sheets.

[0038] Taking the normal paper sheets 20 shown in FIG. 3 and the deformed paper sheets 30 shown in FIG. 4 as examples, an example of a method for determining the deformation of paper sheets in a paper sheet identification device will be described. First, an example in the case of normal paper sheets 20 will be described.

[0039] The normal paper sheets 20 shown in FIG. 3 have four peripheral sides (peripheral side 21, peripheral side 22, peripheral side 23, peripheral side 24). Peripheral side 21 and peripheral side 22 are two opposing peripheral sides, and peripheral side 23 and peripheral side 24 are two opposing peripheral sides.

[0040] In the first comparison process, the slopes of two regions located at different positions on the same peripheral edge are compared. As an example of two regions located at different positions on the same peripheral edge, FIG. 3 shows region 21A and region 21B as regions on peripheral edge 21. Also shown are region 22A and region 22B as regions on peripheral edge 22. Region 21A and region 22A are indicated by a one-dot chain line, and region 21B and region 22B are indicated by a two-dot chain line. Also, in FIG. 3, the boundary line between two regions located at different positions on the same peripheral edge is indicated by a broken line E. In subsequent drawings as well, the boundary line when defining two regions located at different positions on the same peripheral edge is indicated by a broken line E. That is, in the first comparison process, the slopes of region 21A and region 21B, which are two regions located at different positions on the same peripheral edge, are compared. Also, the slopes of region 22A and region 22B are compared.

[0041] In the example shown in FIG. 3, when defining two regions located at different positions on the same peripheral edge, the peripheral edge is divided into two, but the two regions are not limited to the two regions defined by the two-way division. Any two regions on the peripheral edge can be defined. There may be regions on the peripheral edge that are not used in the first comparison process. For example, after dividing the peripheral edge into three and defining three regions, the slopes of two of these regions can be compared, and the remaining one region may not be used for the comparison. Also, the lengths of the two regions used for the comparison may be different. Also, a part of the two regions may overlap.

[0042] The slope of each region can be defined as the acute angle among the angles formed by the peripheral edge in each region with respect to the reference line in the optical image of the paper sheet. The coordinates of a plurality of points on the peripheral edge obtained by edge detection are approximated to a linear function by the least squares method to obtain a straight line. Then, the angle of the straight line with respect to the reference line is determined.

[0043] The reference line can be arbitrarily determined. As shown in FIG. 3, when the paper sheet is regarded as a rectangle, a line extending in a direction parallel to the long side can be used as the reference line. In FIG. 3, the reference line S is indicated by a thin one-dot chain line. In subsequent drawings as well, the reference line is indicated by a thin one-dot chain line S. In addition, when the paper sheets are conveyed in a certain direction in the paper sheet discrimination apparatus, a line extending in the same direction as or perpendicular to the conveyance direction of the paper sheets can be used as a reference line. In this case, the inclination of each region may be a so-called skew angle. Also, a line extending in a direction parallel to one of the peripheral sides can be used as a reference line. Note that the same reference line is used as the reference line for determining the angles of the respective regions for the same paper sheet.

[0044] The reference line in FIG. 3 is a direction parallel to the long side when the paper sheet is regarded as a rectangle, and the angles of regions 21A, 21B, 22A, and 22B with respect to this reference line are all 0°. Since this angle is taken as the inclination of these regions, the inclination of these regions is all 0°.

[0045] In the first comparison process for the normal paper sheet 20 shown in FIG. 3, the inclinations of regions 21A and 21B are compared. Also, the inclinations of regions 22A and 22B are compared.

[0046] The reference (threshold value) of the difference in inclination for comparing the inclinations of two regions and determining that "the inclinations do not match" can be arbitrarily determined according to the strictness for determining a deformed paper sheet. For example, values such as 1°, 3°, and 5° in terms of the absolute value of the difference in inclination can be used as the threshold value for whether the inclinations match or not. In the embodiment described in this specification, it will be described that the threshold value is 5° and it is determined whether the inclinations match or not.

[0047] Since the inclinations of both regions 21A and 21B are 0°, the inclinations match. Also, since the inclinations of both regions 22A and 22B are 0°, the inclinations match. Therefore, in the first comparison process, the paper sheet is determined to be a normal paper sheet (not determined to be a deformed paper sheet).

[0048] In the second comparison process, the slopes of two regions on two opposing peripheral edges are compared. As an example of two regions on two opposing peripheral edges, FIG. 3 shows region 23C as a region on peripheral edge 23 and region 24C as a region on peripheral edge 24. Region 23C is the entire peripheral edge 23, and region 24C is the entire peripheral edge 24. Regions 23C and 24C are indicated by dotted lines.

[0049] As described above, as the reference line in the optical image of the paper sheet, the reference line (reference line S) described in the first comparison process can be used, and the angles of regions 23C and 24C with respect to the reference line are both 90°. Since this angle is defined as the slope of these regions, the slopes of these regions are both 90°.

[0050] In the second comparison process for the normal paper sheet 20 shown in FIG. 3, the slopes of regions 23C and 24C, which are two regions on two opposing peripheral edges, are compared. Since the slopes of regions 23C and 24C are both 90°, the slopes match. Therefore, in the second comparison process, the paper sheet is determined to be a normal paper sheet (not determined to be a deformed paper sheet).

[0051] Also, the two opposing peripheral edges used in the second comparison process may be peripheral edge 21 and peripheral edge 22. In this case, the slopes of regions 21A and 22A, the slopes of regions 21A and 22B, the slopes of regions 21B and 22A, and the slopes of regions 21B and 22B are compared.

[0052] In this case, the entire region 22A is located at a position directly opposite region 21A, and the entire region 22B is located at a position directly opposite region 21B. Region 21A is not located at a position directly opposite region 22B, and region 21B is not located at a position directly opposite region 22A. The regions on the two opposing peripheral edges used in the second comparison process may be regions located at directly opposite positions or regions not located at directly opposite positions. Since the slopes of area 21A, area 21B, area 22A, and area 22B are all 0°, the slopes match in any comparison. Therefore, in the second comparison process, the paper sheet is determined to be a normal paper sheet (not determined to be a deformed paper sheet).

[0053] In the second comparison process, when comparing the slopes of two areas on two opposing peripheral edges, the area may be a partial area of the peripheral edge or the entire area of the peripheral edge. In the above example, when using area 21A, area 21B, area 22A, and area 22B, it is an example of using a partial area of the peripheral edge, and when using area 23C and area 24C, it is an example of using the entire area of the peripheral edge.

[0054] In the paper sheet identification device according to this embodiment, when the slopes do not match in either the first comparison process or the second comparison process, the paper sheet is determined to be a deformed paper sheet. That is, if both the first comparison process and the second comparison process are performed and the slopes match in any of the comparison processes, the paper sheet is determined to be a normal paper sheet. In the case of the normal paper sheet shown in FIG. 3, since the slopes match in both the first comparison process and the second comparison process, it is determined to be a normal paper sheet.

[0055] Next, an example of a method for determining deformation of a paper sheet in a paper sheet identification device will be described using the example of a deformed paper sheet 30.

[0056] The deformed paper sheet 30 shown in FIG. 4 has a shape in which the normal paper sheet 20 shown in FIG. 3 is deformed to bend at its long side. The shape of the deformed paper sheet 30 shown in FIG. 4 is one of the deformation modes typically seen when a polymer banknote is deformed. Similar to the normal paper sheet 20 shown in FIG. 3, the deformed paper sheet 30 shown in FIG. 4 has four peripheral edges (peripheral edge 21, peripheral edge 22, peripheral edge 23, and peripheral edge 24). Peripheral edge 21 and peripheral edge 22 are two opposing peripheral edges, and peripheral edge 23 and peripheral edge 24 are two opposing peripheral edges. The bending point P where the deformable paper sheet 30 bends is within the region 21A of the peripheral edge 21 and within the region 22A of the peripheral edge 22. The peripheral edge 21 and the peripheral edge 22 bend in the same direction (from the bending point P of the side to the upper left direction in FIG. 4). The deformable paper sheet 31 bends upward on the left side as a whole. The angle of bending from the bending point P to the upper left is 10°.

[0057] The setting of the regions on each peripheral edge is the same as that of the normal paper sheet 20 shown in FIG. 3. The reference line S shown in FIG. 4 is shown as a line extending in a direction parallel to the regions 21B and 22B. The angles of the regions 21B and 22B with respect to this reference line are both 0°. The angle of the region 21A is 9°, and the angle of the region 22A is 8°. Since the regions 21A and 22A include the length of the non-bent portion (the portion to the right of the bending point P in FIG. 4), the angles of the regions 21A and 22A are smaller than the 10° angle of bending from the bending point P to the upper left. Since the length of the non-bent portion in the region 21A is shorter than the length of the non-bent portion in the region 22A, the angle of the region 21A is larger than the angle of the region 22A. The angle of the region 23C with respect to the reference line is 80°, and the angle of the region 24C is 90°.

[0058] In the first comparison process for the deformable paper sheet 30 shown in FIG. 4, the inclinations of the region 21A and the region 21B are compared. Also, the inclinations of the region 22A and the region 22B are compared. Since the inclinations of the region 21A and the region 21B are 9° and 0° respectively, the inclinations do not match. Also, since the inclinations of the region 22A and the region 22B are 8° and 0° respectively, the inclinations do not match. Therefore, in the first comparison process, the paper sheet is determined to be a deformable paper sheet.

[0059] In the second comparison process for the deformable paper sheet 30 shown in FIG. 4, the inclinations of the two regions 23C and 24C on the two opposing peripheral edges are compared. Since the inclinations of the region 23C and the region 24C are 80° and 90° respectively, the inclinations do not match. Therefore, in the second comparison process, it is determined as deformed paper sheets.

[0060] Also, when using the two opposing peripheral edges 21 and 22 as the two opposing peripheral edges used in the second comparison process and using the regions 21A, 21B, 22A, and 22B, which are regions on the peripheral edges, in the second comparison process, the determination results differ depending on the combination of the regions used for comparison. Since the inclinations of regions 21A, 21B, 22A, and 22B are 9°, 0°, 8°, and 0° respectively, the inclinations of region 21A and region 22A, and the inclinations of region 21B and region 22B are the same when comparing them. The inclinations of region 21A and region 22B, and the inclinations of region 21B and region 22A do not match when comparing them. Note that although the difference in the inclinations between region 21A and region 22A is 1°, in the example of this embodiment, since the threshold value is set to 5°, the inclinations of region 21A and region 22A are treated as being the same. Therefore, in the second comparison process, there can be both cases where the paper sheets are determined as normal paper sheets and cases where they are determined as deformed paper sheets depending on the combination of the regions used for comparison. When there are a plurality of combinations of the regions used for comparison, the second comparison process is performed for all combinations, and when there is even one combination in which the inclinations do not match, it can be determined as deformed paper sheets. Therefore, by performing the second comparison process for all combinations, the accuracy of determining as deformed paper sheets can be improved. If the regions on the two opposing peripheral edges used in the second comparison process are defined as regions at non-facing positions, for the deformed paper sheets as shown in FIG. 4, the possibility of determining them as deformed paper sheets becomes high.

[0061] In either the first comparison process or the second comparison process, when a plurality of combinations of the regions used for comparison are adopted, if there is even one combination in which the inclinations do not match, the comparison result in that comparison process is "the inclinations do not match". Then, the paper sheets are determined to be deformed paper sheets. In the case of the deformed paper sheets shown in FIG. 4, since there are comparison results in which the inclinations do not match in the first comparison process and the second comparison process, they are determined as deformed paper sheets.

[0062] The deformation determination unit may perform at least the first comparison process (the first comparison process is essential, and the second comparison process may be optional). Also, the deformation determination unit may perform at least the second comparison process (the second comparison process is essential, and the first comparison process may be optional). Also, the deformation determination unit may perform both the first comparison process and the second comparison process. In each of the first comparison process and the second comparison process, there may be at least one set of combinations of two regions for comparing the slopes. If the first comparison process or the second comparison process is performed for one set of combinations, it may be regarded as having performed the first comparison process or the second comparison process.

[0063] As shown in FIGS. 3 and 4, the four peripheral sides of the paper sheet may have two opposing long sides and two opposing short sides.

[0064] The examples shown in FIGS. 3 and 4 are examples in which the four peripheral sides of the paper sheet have two opposing long sides and two opposing short sides, use two regions obtained by dividing a long side into two on the long side, and use the entire short side on the short side. In this case, in the deformation determination unit, as the first comparison process, it is preferable to compare the slopes of two regions at different positions on the same long side. When comparing the slopes of two regions at different positions on the same long side, it is possible to determine that it is a deformed paper sheet using only the shape of one long side, which is advantageous in that it does not require the entire optical image of the paper sheet for the determination. Also, since a polymer banknote is likely to have the shape of the deformed paper sheet shown in FIG. 4 when deformed, it is suitable for determining a deformed paper sheet obtained by deforming a polymer banknote.

[0065] Further, as the second comparison process, it is preferable to compare the slopes of two opposing short sides. When comparing the slopes of two opposing short sides, it is possible to determine that it is deformed paper sheet using only the shapes of the two short sides, which is advantageous in that it does not require the entire optical image of the paper sheet for the determination. Further, since a polymer banknote is likely to have the shape of the deformed paper sheet shown in FIG. 4 when deformed, it is suitable for the determination of the deformed paper sheet in which the polymer banknote is deformed.

[0066] Hereinafter, an embodiment in which the regions used for the first comparison process and the second comparison process are different when the four peripheral sides of the paper sheet have two long sides facing each other and two short sides facing each other will be described.

[0067] (Embodiment 2) In the present embodiment, the four peripheral sides of the paper sheet have two long sides facing each other and two short sides facing each other, and two regions obtained by dividing each long side into two are used for the long sides, and two regions obtained by dividing each short side into two are used for the short sides. FIG. 5 is a plan schematic view showing another example of the regions used for the first comparison process and the second comparison process, taking a normal paper sheet as an example.

[0068] In the form shown in FIG. 5, regions 21A and 21B as regions on the peripheral side 21, and regions 22A and 22B as regions on the peripheral side 22, which are obtained by dividing the peripheral sides 21 and 22, which are long sides, into two respectively, are used. The description of using these regions for the first comparison process and the second comparison process is the same as in the case of Embodiment 1 shown in FIG. 3.

[0069] Further, regions 23A and 23B as regions on the peripheral side 23, and regions 24A and 24B as regions on the peripheral side 24, which are obtained by dividing the peripheral sides 23 and 24, which are short sides, into two respectively, are used. Regions 23A and 24A are indicated by one-dot chain lines, and regions 23B and 23B are indicated by two-dot chain lines.

[0070] When using these regions for the first comparison process and the second comparison process, it is as follows. When used for the first comparison process, compare the slopes of region 23A and region 23B, which are two regions at different positions on the same peripheral side, and the slopes of region 24A and region 24B.

[0071] When used for the second comparison process, compare the slopes of region 23A and region 24A, the slopes of region 23A and region 24B, the slopes of region 23B and region 24A, and the slopes of region 23B and region 24B.

[0072] In this case, in the deformation determination unit, as the first comparison process, the slopes of two regions at different positions on the same long side may be compared.

[0073] (Embodiment 3) In this embodiment, the four peripheral sides of the paper sheet have two long sides facing each other and two short sides facing each other, and the entire long side is used for the long side and the entire short side is used for the short side.

[0074] FIG. 6 is a plan schematic view showing another example of the regions used for the second comparison process, taking a normal paper sheet as an example. In this embodiment, since the slopes of two regions at different positions on the same peripheral side are not compared, the first comparison process is not performed, and only the second comparison process is performed.

[0075] FIG. 6 shows region 21C as a region on peripheral side 21, region 22C as a region on peripheral side 22, region 23C as a region on peripheral side 23, and region 24C as a region on peripheral side 24. Region 21C, region 22C, region 23C, and region 24C are the entire peripheral sides 21, 22, 23, and 24, respectively. These regions are used for the second comparison process. Region 21C, region 22C, region 23C, and region 24C are shown by dotted lines.

[0076] In the second comparison process, compare the slopes of region 21C and region 22C, which are two regions on two opposing peripheral sides, and the slopes of region 23C and region 24C.

[0077] In this case, in the deformation determination unit, as the second comparison process, the slopes of two opposing short sides may be compared.

[0078] (Embodiment 4) In the present embodiment, the four peripheral edges of the paper sheet have two long sides facing each other and two short sides facing each other, and in the second comparison process, the slopes of two regions at positions where at least a part does not face each other on the two opposing long sides are compared.

[0079] FIG. 7 is a schematic plan view showing another example of the region used for the second comparison process, taking a normal paper sheet as an example.

[0080] In the form shown in FIG. 7, the peripheral edges 21 and 22, which are long sides, are each divided into two, and the regions 21A and 21B as regions on the peripheral edge 21, and the regions 22A and 22B as regions on the peripheral edge 22 are used. However, the division positions of the peripheral edge 21 and the peripheral edge 22 are different, and the peripheral edge 21 and the peripheral edge 22 are divided at positions where the region 21A is longer than the region 21B and the region 22A is shorter than the region 22B.

[0081] When the two opposing peripheral edges used in the second comparison process are the peripheral edge 21 and the peripheral edge 22, the slopes of the region 21A and the region 22A, the slopes of the region 21A and the region 22B, the slopes of the region 21B and the region 22A, and the slopes of the region 21B and the region 22B are compared. The entire region 22A and a left part of the region 22B face the position of the region 21A. A right part of the region 22B faces the position of the region 21B. When comparing the slopes of the region 21A and the region 22A, a right part of the region 21A does not face the region 22A. When comparing the slopes of the region 21A and the region 22B, a right part of the region 21A faces a left part of the region 22B, but a left part of the region 21A does not face the region 22B, and a right part of the region 22B does not face the region 21A. When comparing the slopes of region 21B and region 22A, a part on the right side of region 22A faces a part on the left side of region 21B, but a part on the left side of region 22A does not face region 21B, and a part on the right side of region 12B does not face region 22A. When comparing the slopes of region 21B and region 22B, a part on the left side of region 22B does not face region 21B.

[0082] In the second comparison process, by comparing the slopes of two regions that are at positions where at least a part does not face each other on two opposite long sides, it is also possible to determine whether the paper sheets are deformed paper sheets.

[0083] [Other examples of deformed paper sheets] Hereinafter, other embodiments with different shapes of deformed paper sheets will be described. Each of the examples of the deformed paper sheets shown below is a deformed paper sheet obtained by deforming a rectangular paper sheet having two opposite long sides and two opposite short sides. Each of the deformed paper sheets shown below has four peripheral sides (peripheral side 21, peripheral side 22, peripheral side 23, peripheral side 24), similar to the normal paper sheet 20 shown in FIG. 3 and the deformed paper sheet 30 shown in FIG. 4. Peripheral side 21 and peripheral side 22 are two opposite peripheral sides, and peripheral side 23 and peripheral side 24 are two opposite peripheral sides.

[0084] (Embodiment 5) FIG. 8 is a plan schematic view schematically showing another example of a deformed paper sheet. FIG. 8 shows a deformed paper sheet 31 which is a deformed paper sheet. The bending points P where the deformed paper sheet 31 bends are within region 23B of the peripheral side 23 which is a short side and within region 23A of the peripheral side 24. That is, the positions of the bending points where the deformed paper sheet bends are different from those of the deformed paper sheet 30 shown in FIG. 4. The peripheral side 23 and the peripheral side 24 are bent in the same direction (in FIG. 8, from the bending point P of the side to the lower right direction). The deformed paper sheet 31 is bent to the right at the lower part as a whole.

[0085] When performing at least one of the first comparison process and the second comparison process on the deformed paper sheet 31 to determine whether the paper sheet is a deformed paper sheet, any of the regions described so far may be used for the first comparison process and the second comparison process. FIG. 8 shows a region 21C that is the entire peripheral edge 21 which is the long side, and a region 22C that is the entire peripheral edge 22. Also shown are a region 23A and a region 23B as regions on the peripheral edge 23, and a region 24A and a region 24B as regions on the peripheral edge 24, which are obtained by dividing the short peripheral edges 23 and 24 into two parts respectively.

[0086] For example, when comparing the slopes of two regions, i.e., region 23A and region 23B, which are at different positions on the same peripheral edge, and the slopes of region 24A and region 24B, in the first comparison process, since these slopes do not match, the paper sheet shown in FIG. 8 is determined to be a deformed paper sheet. Also, when comparing the slopes of two regions, i.e., region 21C and region 22C, which are on two opposing peripheral edges, in the second comparison process, since these slopes do not match, the paper sheet shown in FIG. 8 is determined to be a deformed paper sheet.

[0087] (Embodiment 6) FIG. 9 is a plan schematic view schematically showing another example of a deformed paper sheet. FIG. 9 shows a deformed paper sheet 32 which is a deformed paper sheet. The bending points P where the deformed paper sheet 32 bends are within the region 21A of the peripheral edge 21 which is the long side, and within the region 22A of the peripheral edge 22. The positions of the bending points where the deformed paper sheet bends are the same as those of the deformed paper sheet 30 shown in FIG. 4, but the direction of deformation is different, and the peripheral edges 21 and 22 are bent in different directions. Specifically, the peripheral edge 21 is bent from the bending point P of the side in the lower left direction, and the peripheral edge 22 is bent from the bending point P of the side in the upper left direction. And the length of the peripheral edge 23 which is the short side is shorter than the length of the opposing peripheral edge 24 which is the short side.

[0088] When performing at least one of a first comparison process and a second comparison process on the deformed paper sheet 32 to determine whether the paper sheet is a deformed paper sheet, any of the regions described so far may be used as the regions used for the first comparison process and the second comparison process. FIG. 9 shows a region 21A and a region 21B as regions on the peripheral edge 21, and a region 22A and a region 22B as regions on the peripheral edge 22, which are obtained by dividing the peripheral edges 21 and 22, which are the long sides, into two parts respectively. Also shown are a region 23C which is the entire peripheral edge 23 that is the short side, and a region 24C which is the entire peripheral edge 24.

[0089] For example, when comparing the slopes of the two regions 21A and 21B, which are two regions at different positions on the same peripheral edge, and the slopes of the regions 22A and 22B in the first comparison process, since these slopes do not match, the paper sheet shown in FIG. 9 is determined to be a deformed paper sheet. Also, when comparing the slopes of the two regions 21A and 22A, which are two regions on the two opposing peripheral edges, in the second comparison process, since these slopes do not match, the paper sheet shown in FIG. 9 is determined to be a deformed paper sheet.

[0090] (Embodiment 7) FIG. 10 is a schematic plan view schematically showing another example of a deformed paper sheet. FIG. 10 shows a deformed paper sheet 33 which is a deformed paper sheet. The bending point P where the deformed paper sheet 33 bends is only within the region 21A of the peripheral edge 21 which is the long side, and the peripheral edge 21 bends downward to the left from the bending point P of the side. And the length of the peripheral edge 23 which is the short side is shorter than the length of the peripheral edge 24 which is the opposing short side. The peripheral edge 22 which is the long side is not deformed and is linear.

[0091] When performing at least one of a first comparison process and a second comparison process on the deformed paper sheet 33 to determine whether the paper sheet is a deformed paper sheet, any of the regions described so far may be used as the regions used for the first comparison process and the second comparison process. FIG. 10 shows a region 21A and a region 21B as regions on the peripheral edge 21, and a region 22A and a region 22B as regions on the peripheral edge 22, which are obtained by dividing the long peripheral edges 21 and 22 into two parts respectively. Also shown are a region 23C which is the entire short peripheral edge 23, and a region 24C which is the entire peripheral edge 24.

[0092] For example, when comparing the slopes of two regions, i.e., region 21A and region 21B, which are at different positions on the same peripheral edge in the first comparison process, since these slopes do not match, the paper sheet shown in FIG. 10 is determined to be a deformed paper sheet. Also, when comparing the slopes of two regions, i.e., region 21A and region 22A, which are on two opposing peripheral edges in the second comparison process, since these slopes do not match, the paper sheet shown in FIG. 10 is determined to be a deformed paper sheet.

[0093] (Embodiment 8) FIG. 11 is a schematic plan view schematically showing another example of a deformed paper sheet. FIG. 11 shows a deformed paper sheet 34 which is a deformed paper sheet. In the deformed paper sheet 34, the short peripheral edge 24 is deformed so as to incline upward to the left as a whole. There is no inflection point within the peripheral edge 24 and the peripheral edge 24 is linear. Also, there is no inflection point within any of the other peripheral edges and all the peripheral edges are linear. And the length of the long peripheral edge 21 is shorter than the length of the opposing long peripheral edge 22.

[0094] When performing at least one of the first comparison process and the second comparison process on the deformed paper sheet 34 to determine whether the paper sheet is a deformed paper sheet, any of the regions described above may be used for the first comparison process and the second comparison process. However, for this deformed paper sheet 34, since it is not determined to be a deformed paper sheet by comparing the slopes of two regions at different positions on the same peripheral edge, it is not determined to be a deformed paper sheet by the first comparison process, and is determined to be a deformed paper sheet by the second comparison process.

[0095] FIG. 11 shows a region 21C that is the entire peripheral edge 21 which is the long side, and a region 22C that is the entire peripheral edge 22. Also shown are a region 23C that is the entire peripheral edge 23 which is the short side, and a region 24C that is the entire peripheral edge 24.

[0096] In the second comparison process, when comparing the slopes of the two regions, region 23C and region 24C, on two opposing peripheral edges, since these slopes do not match, the paper sheet shown in FIG. 11 is determined to be a deformed paper sheet.

[0097] In each of the embodiments described so far, as an example of a normal paper sheet that has not been deformed, a paper sheet that is a rectangle with four peripheral edges having two short sides and two long sides has been exemplified. However, the normal paper sheet that has not been deformed may be a square, and it is possible to determine whether it is a deformed paper sheet in the same manner as when the normal paper sheet is a rectangle.

[0098] (Embodiment 9) The configuration of the paper sheet processing apparatus according to this embodiment will be described with reference to FIGS. 12 and 13. FIG. 12 is a perspective schematic view showing the appearance of an example of the paper sheet processing apparatus. FIG. 13 is a block diagram for explaining an example of the configuration of the paper sheet processing apparatus.

[0099] The paper sheet processing apparatus according to this embodiment may have, for example, the configuration shown in FIG. 12. The paper sheet processing apparatus 300 shown in FIG. 12 incorporates a paper sheet identification device 1 (see FIGS. 1 and 13) that performs identification processing of paper sheets, a hopper 301 on which a plurality of paper sheets to be processed are placed in a stacked state, two reject portions 302 from which the rejected paper sheets are discharged, an operation unit 303 for inputting instructions from an operator, four stacking units 306a to 306d for classifying and stacking the paper sheets whose denomination, authenticity, and integrity have been identified within the housing 304, and a display unit 305 for displaying information such as the identification and counting results of the paper sheets and the stacking status of each of the stacking units 306a to 306d.

[0100] As shown in FIG. 13, the paper sheet processing apparatus 300 further includes a conveyance unit 310, a main body storage unit 330, and a main body control unit 320.

[0101] The conveyance unit 310 includes a conveyance roller for conveying paper sheets, a drive mechanism (a drive source and a driving force transmission mechanism) for driving the conveyance roller, and the like.

[0102] The main body storage unit 330 is composed of a storage device such as a semiconductor memory (RAM or ROM) and a hard disk, and stores various programs and information (data) for controlling the paper sheet processing apparatus 300.

[0103] The main body control unit 320 is a controller that controls each part of the paper sheet processing apparatus 300, and is configured as a computer system including a CPU and various hardware (for example, FPGA) controlled by the CPU. The main body control unit 320 realizes various processes by executing a predetermined software program stored in the main body storage unit 330 (which may be a storage unit provided separately from the main body storage unit 330) in its CPU.

[0104] As described above, the embodiments have been described with reference to the drawings, but the present disclosure is not limited to the above embodiments. Further, the configurations of the respective embodiments may be appropriately combined or changed without departing from the gist of the present disclosure.

Industrial Applicability

[0105] As described above, the present disclosure is a technique useful for discriminating paper sheets deformed by heat or the like.

Explanation of Reference Numerals

[0106] 1: Paper sheet discrimination device 10: Deformation determination unit 11: First comparison processing unit 12: Second comparison processing unit 20: Normal paper sheets 21, 22, 23, 24: Peripheral edges 21A, 21B, 21C, 22A, 22B, 22C, 23A, 23B, 23C, 24A, 24B, 24C: Regions on the peripheral edge 30, 31, 32, 33, 34: Deformed paper sheets 300: Paper sheet processing device 301: Hopper 302: Reject section 303: Operation section 304: Housing 305: Display section 306a, 306b, 306c, 306d: Integration section 310: Conveyor section 330: Main body memory section 320: Main body control section

Claims

1. In an optical image of paper sheets, among the regions on the four peripheral edges of the paper sheets, a first comparison process of comparing the slopes of two regions at different positions on the same peripheral edge, and a second comparison process of comparing the slopes of two regions on two opposite peripheral edges, at least one of the comparison processes is performed. When the slopes do not match in any of the comparison processes, a deformation determination unit that determines the paper sheets as deformed paper sheets is provided. A paper sheet identification device characterized by this.

2. The paper sheet identification device according to claim 1, wherein the deformation determination unit performs at least the first comparison process.

3. The paper sheet identification device according to claim 1, wherein the deformation determination unit performs at least the second comparison process.

4. The four peripheral edges have two opposite long sides and two opposite short sides. In the deformation determination unit, as the first comparison process, the slopes of two regions at different positions on the same long side are compared. The paper sheet identification device according to claim 1, characterized by this.

5. The four peripheral edges have two opposite long sides and two opposite short sides. In the deformation determination unit, as the second comparison process, the slopes of two regions at positions where at least a part does not face each other on two opposite long sides are compared. The paper sheet identification device according to claim 1, characterized by this.

6. The four peripheral edges have two opposite long sides and two opposite short sides. In the deformation determination unit, as the second comparison process, the slopes of two opposite short sides are compared. The paper sheet identification device according to claim 1, characterized by this.

7. The paper sheets are polymer banknotes, and the deformed paper sheets are polymer banknotes in which deformation has occurred. The paper sheet identification device according to claim 1, characterized by this.

8. The optical image of the paper sheets is an infrared image. The paper sheet identification device according to claim 1, characterized by this.

9. A paper sheet processing device characterized by comprising the paper sheet identification device according to any one of claims 1 to 8.

10. In an optical image of paper sheets, at least one of a first comparison process of comparing the slopes of two regions at different positions on the same peripheral edge among the regions on the four peripheral edges of the paper sheets, and a second comparison process of comparing the slopes of two regions on two opposing peripheral edges is performed, and a deformation determination step of determining the paper sheets as deformed paper sheets when the slopes do not match in any of the comparison processes is performed. A method for identifying paper sheets characterized by this.

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