JP2016071476A - Paper sheet identification device and method for specifying presence or absence of motion thread in paper sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the specification accuracy of the presence or absence of a motion thread in a paper sheet identification device.SOLUTION: The paper sheet identification device includes a first light source part which irradiates one surface of a paper sheet with diffusion light, a first sensor which receives first transmitted light radiated from the first light source part and transmitted through the paper sheet, a second light source part which irradiates the other surface of the paper sheet with light, a second sensor which receives second transmitted light radiated from the second light source part and transmitted through the paper sheet, an image forming part which generates a first image on the basis of the first transmitted light and generates a second image on the basis of the second transmitted light, a pattern identification part which identifies whether or not each of the first image and the second image includes a predetermined pattern possessed by the motion thread, and a specification part which specifies that the paper sheet has the motion thread, when only one of the first image and the second image includes the predetermined pattern.SELECTED DRAWING: Figure 2

Description

  The present invention relates to identification of the presence or absence of a motion thread in paper sheets.

  In the case of paper sheets such as banknotes and securities, a motion thread may be used in order to prevent forgery. The motion sled includes an image printed on a paper sheet and a microlens array arranged on the image. By tilting a paper sheet having a motion thread, a pattern called an icon on the print surface appears to move, or a different icon appears depending on the tilt angle. The microlens array is designed to form images at different positions on the printing surface depending on the viewing angle.

  Since the motion thread is not easy to manufacture, the authenticity of the paper sheet can be determined by the presence or absence of the motion thread. Patent Document 1 irradiates light from two different directions on one side of a paper sheet, receives reflected light reflected by the paper sheet with a line sensor, and compares the two obtained images. Thus, a paper sheet identification device that determines the presence or absence of a motion thread is disclosed.

JP 2013-20540 A

  In the paper sheet identification device of Patent Document 1, a stable image cannot be obtained unless the angle between each light source and the paper sheet is constant. However, in general, the paper sheets are bent at a high speed continuously in the paper sheet identification device, and the height thereof is not constant. For this reason, in the paper sheet identification apparatus of patent document 1, since the position of the icon in each image does not become fixed, there existed a problem that the specific precision of the presence or absence of a motion thread fell.

  Therefore, the present invention provides a paper sheet identification device capable of improving the accuracy of specifying the presence or absence of a motion thread.

  In order to solve the above-described problems, according to the present invention, there is provided a paper sheet identification device that specifies the presence or absence of a motion thread in a paper sheet. The paper sheet identification apparatus includes: a first light source unit that irradiates one surface of the surface of the paper sheet with diffused light; and an irradiation from the first light source unit that faces the first light source unit. A first sensor that receives the first transmitted light transmitted through the paper sheet; a second light source unit that irradiates light to the other surface of the surface of the paper sheet; and the second light source. A second sensor that receives the second transmitted light that is irradiated from the second light source unit and is transmitted through the paper sheet, and generates a first image based on the first transmitted light. An image generation unit that generates a second image based on the second transmitted light; whether the first image and the second image each include a predetermined pattern that the motion thread has A pattern identifying unit for identifying the above; only one of the first image and the second image; It comprises; if it contains a constant pattern, a specifying unit the paper sheet is specified as having the motion thread.

ADVANTAGE OF THE INVENTION According to this invention, the paper sheet identification device which can improve the specific precision of the presence or absence of a motion thread can be provided.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is explanatory drawing which shows schematic structure of the banknote identification device 10 as one Embodiment of this invention, and the structure of banknote BL. 1 is a perspective view showing a schematic configuration of an optical sensor unit 100. FIG. 2 is a perspective view showing a detailed configuration of a first light guide light source 110. FIG. It is a perspective view explaining a mode that bill BL passes optical sensor part 100. FIG. It is sectional drawing explaining the optical path in the 1st light guide light source 110. FIG. It is sectional drawing explaining the optical path in the 1st light guide light source 110. FIG. It is a schematic diagram explaining the optical path at the time of light being irradiated toward the banknote BL from the 1st light guide light source 110. FIG. It is a schematic diagram explaining the optical path when light is irradiated toward the banknote BL from the 2nd light guide light source 120. FIG. It is explanatory drawing which shows the example of a 1st image. It is explanatory drawing which shows the example of a 2nd image. 10 is a flowchart showing a procedure of processing for specifying the presence or absence of a motion thread M. It is a schematic diagram explaining the optical path at the time of light being irradiated toward the banknote BL from the point light source 310 in a comparative example.

A. Embodiment A-1. Device Configuration FIG. 1 is an explanatory diagram showing a schematic configuration of a banknote recognition device 10 as an embodiment of the present invention and a configuration of a banknote BL. FIG. 1A is a cross-sectional view schematically showing the configuration of the banknote recognition device 10, and FIG. 1B is a cross-sectional view schematically showing the configuration of the banknote BL handled in the banknote recognition device 10. . The banknote recognition apparatus 10 shown to FIG. 1 (A) conveys the banknote BL one by one continuously, optically reads the surface of the banknote BL, and identifies the money type and authenticity of a banknote. In this embodiment, the banknote identification device 10 is used by being incorporated in an automated teller machine (ATM). In addition, it may replace with ATM and may be incorporated and used for various apparatuses which handle banknotes, such as a banknote counter, a payment machine, and a ticket vending machine. In the figure, the X axis and the Y axis perpendicular to each other are parallel to the horizontal plane, the + Z direction indicates a vertically upward direction, and the −Z direction indicates a vertically downward direction. The conveyance direction dd indicated by the white arrow means the conveyance direction of the banknote BL in the banknote recognition apparatus 10, and is parallel to the Y axis in this embodiment.

  A bill BL shown in FIG. 1B is a genuine note, and has a motion thread M on one surface of the surface. The motion sled M includes a print image M1 and a microlens array M2. The print image M1 is a minute image printed on the banknote BL. The microlens array M2 has a plurality of microlenses and is configured of a resin sheet. The individual lenses of the microlens array M2 are configured such that a predetermined pattern (hereinafter also referred to as “icon”) can be seen by forming an image at a predetermined location in the printed image M1. That is, the printed image M1 does not have any significant pattern when viewed without the microlens array M2, but when viewed through the microlens array M2, a predetermined place is imaged. , Will have an icon. FIG. 1B schematically shows an icon group IC in which circular patterns and triangular patterns are alternately arranged as icons appearing on the banknote BL. By tilting the banknote BL, a circular pattern portion is imaged and only a circular icon is visible in the icon group IC, or a triangular pattern portion is imaged and only a triangular icon is visible. Although not shown, an optical spacer made of resin is disposed between the print image M1 and the microlens array M2, and the bill BL, the print image M1, and the microlens array M2 are integrated. . In the fake note, the microlens array M2 is omitted or the entire motion thread M is omitted.

  The banknote recognition apparatus 10 includes an insertion detection sensor 20, a conveyance path 30, a plurality of gears 40, a plurality of conveyance rollers 50, a rotation detection unit 60, a control unit 70, a thickness sensor 80, and an optical sensor unit 100. With.

  The insertion detection sensor 20 is disposed in the vicinity of the insertion slot of the banknote BL, and detects that the banknote BL has been inserted into the banknote identification device 10. In the present embodiment, the insertion detection sensor 20 includes a light emitting diode and a phototransistor that are opposed to each other with the conveyance path 30 in between. The conveyance path 30 functions as a conveyance path of the banknote BL in the banknote identification device 10. The plurality of gears 40 are driven by power supplied from an ATM (not shown) that is a host device to rotate the plurality of transport rollers 50. The some conveyance roller 50 is arrange | positioned along the conveyance path 30, and conveys the banknote BL in a Y-axis direction (conveyance direction dd). The rotation detection unit 60 detects the rotation of the transport roller 50. The control unit 70 is a computer including a CPU, a memory, and the like (not shown), and controls various operations in the banknote recognition apparatus 10. The thickness sensor 80 detects the thickness of the banknote BL conveyed through the conveyance path 30. In the present embodiment, the thickness sensor 80 is an eddy current displacement sensor including a pair of metal rollers facing each other with the conveyance path 30 therebetween and a coil positioned vertically above the metal roller. Instead of the eddy current displacement sensor, any other sensor such as a capacitance sensor may be used as the thickness sensor 80.

  The control unit 70 includes an image generation unit 71, a pattern identification unit 72, and a specification unit 73. The image generation unit 71 generates a first image and a second image to be described later. The pattern identifying unit 72 identifies whether the first image and the second image each include a predetermined icon that the motion thread M has. The specifying unit 73 specifies the presence or absence of the motion thread M.

  FIG. 2 is a perspective view showing a schematic configuration of the optical sensor unit 100. The optical sensor unit 100 includes two sensor units (a first sensor unit 101 and a second sensor unit 102). Since the two sensor units 101 and 102 have a configuration in which they are vertically reversed, the first sensor unit 101 will be described as a representative. The two sensor units 101 and 102 are arranged at a predetermined distance dy along the transport direction dd. In the present embodiment, the distance dy is shorter than the length of the banknote BL in the short direction. The distance dy may be equal to or longer than the length of the banknote BL in the short direction. The first sensor unit 101 is located on the downstream side in the transport direction dd, and the second sensor unit 102 is located on the upstream side in the transport direction dd.

  The first sensor unit 101 includes a first light guide light source 110, a first rod lens array 130, and a first line sensor 150. The first light guide light source 110, the first rod lens array 130, and the first line sensor 150 all have a columnar appearance and are arranged so that the longitudinal direction is parallel to the X-axis direction. Has been. In addition, the first light guide light source 110, the first rod lens array 130, and the first line sensor 150 are all arranged so that the centers in the short direction are aligned along the Z-axis direction. Specifically, the first light guide light source 110 is positioned most in the + Z direction (vertically upward), the first line sensor 150 is positioned most in the −Z direction (vertically downward), and the first rod lens array. 130 is disposed between the first light guide light source 110 and the first line sensor 150. A gap is provided between the first light guide light source 110 and the first rod lens array 130 and between the first rod lens array 130 and the first line sensor 150 by a predetermined distance. ing. A distance dz along the Z-axis direction of the gap between the first light guide light source 110 and the first rod lens array 130 is longer than the thickness of the bill BL. As shown in FIG. 2, the gap between the first light guide light source 110 and the first rod lens array 130 forms a part of the transport path 30.

  The first light guide light source 110 emits diffused light downward (toward the conveyance path 30). The detailed configuration of the first light guide light source 110 will be described later.

  The first rod lens array 130 has a structure in which a plurality of rod-shaped lenses having an optical axis center in a direction parallel to the Z-axis direction are arranged in the X-axis direction. The first rod lens array 130 faces the first light guide light source 110 across the transport path 30. The first rod lens array 130 forms an image on the first line sensor 150 of light (hereinafter referred to as “first transmitted light”) that has been irradiated from the first light guide light source 110 and transmitted through the bill BL. Let

  The first line sensor 150 converts the first transmitted light received through the first rod lens array 130 into an electric signal and sends it to the control unit 70. The first line sensor 150 is a sensor having the X-axis direction as the main scanning direction and the Y-axis direction (conveying direction) as the sub-scanning direction, and is configured by a photodiode. Instead of the photodiode, another light receiving element such as a phototransistor may be used.

  In this embodiment, the length along the X-axis direction of each component (the first light guide light source 110, the first rod lens array 130, and the first line sensor 150) constituting the first sensor unit 101 is as follows. The length of the bill BL is approximately equal to the length of the bill BL, and the entire surface of the bill BL can be imaged.

  FIG. 3 is a perspective view showing a detailed configuration of the first light guide light source 110. The first light guide light source 110 includes a light guide 111, a diffuse reflection paint 112, and two LEDs 113.

  The light guide 111 is formed of a resin cylindrical lens having a convex surface 111t extending in the X-axis direction, and is disposed so that the convex surface 111t faces the first rod lens array 130. In addition, it may replace with resin and you may use other highly transparent materials, such as glass. The diffuse reflection paint 112 is applied over the entire plane of the light guide 111 that faces the convex surface 111t, and functions as a light diffuser. The two LEDs 113 are arranged to face the end surface in the + X direction and the end surface in the −X direction of the light guide 111, respectively. The two LEDs 113 each emit visible light toward the light guide 111. Note that light of other wavelengths (infrared light or ultraviolet light) may be irradiated instead of visible light.

  As described above, the configuration of the second sensor unit 102 has a configuration obtained by vertically inverting the configuration of the first sensor unit 101 described above. In the second sensor unit 102, the second light guide light source 120 corresponds to the first light guide light source 110 of the first sensor unit 101. Similarly, in the second sensor unit 102, the second rod lens array 140 is replaced with the first rod lens array 130 of the first sensor unit 101, and in the second sensor unit 102, the second line sensor 160 is replaced with the first sensor unit 101. Respectively corresponding to the first line sensor 150. Accordingly, the second light source 120 of the second sensor unit 102 irradiates the diffused light upward (toward the transport path 30). Further, the second rod lens array 140 of the second sensor unit 102 faces the second light guide light source 120 with the conveyance path 30 interposed therebetween. In addition, the second rod lens array 140 transmits light (hereinafter referred to as “second transmitted light”) irradiated from the second light guide light source 120 and transmitted through the bill BL to the second line sensor 160. To form an image. Further, the second line sensor 160 converts the received second transmitted light into an electric signal and sends it to the control unit 70.

  In this embodiment, the banknote BL corresponds to the paper sheet in the claims, and the banknote identification device 10 corresponds to the paper sheet identification apparatus in the claims. Further, the first light guide light source 110 is in the first light source section in the claims, the second light guide light source 120 is in the second light source section in the claims, and the first line sensor 150 is in the claims. The first line sensor 160 corresponds to the first sensor, and the conveyance path 30 corresponds to the conveyance unit in the claims.

A-2. FIG. 4 is a perspective view for explaining how the bill BL passes through the optical sensor unit 100. The overall operation of the banknote recognition apparatus 10 will be described with reference to FIGS. 1 and 4. In this embodiment, the banknote BL is inserted into the banknote identification device 10 so that the X-axis direction is the longitudinal direction and the Y-axis direction is the short direction. Moreover, the banknote BL is conveyed through the conveyance path 30 in a state where the surface having the motion sled M is directed vertically upward. Note that the bills BL may be inserted and transported such that the X-axis direction is the short direction and the Y-axis direction is the long direction.

  When the bill BL is inserted into the bill recognition device 10, the insertion detection sensor 20 detects the insertion of the bill BL. The insertion detection sensor 20 sends a signal indicating insertion detection to the control unit 70, and the control unit 70 sends a similar signal to the control unit of a host device (ATM) (not shown). The control unit of the host device drives the gear 40 by a drive motor included in the host device, whereby the transport roller 50 rotates. The rotation detection unit 60 detects the rotation of the transport roller 50 and sends a signal indicating rotation detection to the control unit 70. When receiving a signal indicating rotation detection from the rotation detection unit 60, the control unit 70 sends a light source lighting signal and a line sensor drive signal synchronized with the rotation of the transport roller 50 to the optical sensor unit 100. As a result, the first light guide light source 110 and the second light guide light source 120 are turned on, and the first line sensor 150 and the second line sensor 160 are driven.

  The 1st light guide light source 110 and the 2nd light guide light source 120 irradiate light toward the bill BL conveyed on the conveyance path 30, respectively. The first transmitted light irradiated from the first light guide light source 110 and transmitted through the bill BL is guided to the first rod lens array 130 and received by the first line sensor 150. The first line sensor 150 converts the received first transmitted light into an electric signal and transmits it to the image generation unit 71. Similarly, the second transmitted light emitted from the second light guide light source 120 and transmitted through the bill BL is guided to the second rod lens array 140 and received by the second line sensor 160. The second line sensor 160 converts the received second transmitted light into an electric signal and transmits it to the image generation unit 71. The image generation unit 71 generates a first image based on the first transmitted light signal, and generates a second image based on the second transmitted light signal. The pattern identifying unit 72 identifies whether or not the generated first image and second image each include a predetermined icon that the motion thread M has. The identifying unit 73 identifies the presence or absence of the motion thread M based on the identification result of the pattern identifying unit 72. The identification of the presence or absence of the motion thread M will be described in detail with reference to FIG. The presence or absence of the motion thread M specified by the specifying unit 73 is used for authenticity determination of the banknote BL. Specifically, for example, if it is specified that there is no motion thread M, it is determined that the bill BL is a fake bill. If it is specified that the motion thread M is present, it is determined to be a genuine note on the premise that other conditions (such as a condition relating to thickness described later) are provided.

  The thickness sensor 80 detects the thickness of the bill BL being conveyed. When the banknote BL is sandwiched between the pair of metal rollers in the thickness sensor 80, the metal roller positioned vertically above the transport path 30 of the pair of metal rollers moves up and down according to the thickness of the banknote BL. As the metal roller moves up and down, the distance between the metal roller and the coil positioned vertically above the metal roller changes, and the current flowing through the coil changes. The thickness sensor 80 converts the current flowing through the coil into a signal and transmits the signal to the control unit 70. The control unit 70 calculates the thickness of the banknote BL based on the signal received from the thickness sensor 80. The thickness of the banknote BL calculated by the control unit 70 is used for determining the number of sheets (whether a plurality of banknotes BL are overlapped and being conveyed) and for determining the authenticity of the banknote BL (whether the banknote BL has a predetermined thickness). Is done.

A-3. Optical Path FIGS. 5 and 6 are cross-sectional views for explaining the optical path in the first light guide light source 110. FIG. 5 shows a cross section when the first light guide light source 110 is cut along the XZ plane. FIG. 6 shows a cross section when the first light guide light source 110 is cut along the YZ plane. In the drawing, an arrow indicated by a broken line indicates an optical path until light emitted from the two LEDs 113 passes through the light guide 111 and reaches the diffuse reflection paint 112. In the drawing, an arrow indicated by a solid line indicates an optical path until the light reflected by the diffuse reflection paint 112 passes through the light guide 111 and is emitted from the convex surface 111t. The light emitted from the two LEDs 113 is diffusely reflected by the diffuse reflection paint 112 of the light guide 111, and thus is diffused and emitted from the convex surface 111t. “Diffused light” means light emitted in various directions from a plurality of emission points. As shown in FIG. 5, the diffuse reflection coating 112 forms a plurality of reflected light emission points.

  FIG. 7 is a schematic diagram for explaining an optical path when light is irradiated from the first light guide light source 110 toward the bill BL. In the figure, light is irradiated on the surface of the bill BL having the motion sled M. The arrow in the figure indicates the optical path. The diffused light emitted from the first light guide light source 110 enters the microlens array M2 from all directions. Thereafter, the light refracted by the microlens array M2 travels in all directions and illuminates the entire surface of the printed image M1. At this time, since a predetermined place in the print image M1 is not imaged, no icon is imaged on the first line sensor 150. Accordingly, the first image does not include the predetermined icon that the motion thread M has.

  FIG. 8 is a schematic diagram for explaining an optical path when light is irradiated from the second light guide light source 120 toward the bill BL. In the figure, light is irradiated on the surface of the bill BL that does not have the motion thread M. If the front and back direction of the banknote BL is the same as the direction shown in FIG. 7, the second light guide light source 120 irradiates the surface of the banknote BL that does not have the motion thread M. The arrow in the figure indicates the optical path. The diffused light emitted from the second light guide light source 120 enters the bill BL (printed image M1) from all directions. Thereafter, the light transmitted through the print image M1 is refracted by the microlens array M2 and reaches the second line sensor 160 through the second rod lens array 140. As the light is refracted by the microlens array M2, a predetermined icon (a circular icon in the figure) is formed on the second line sensor 160. Therefore, the second image includes a predetermined icon that the motion thread M has.

  FIG. 9 is an explanatory diagram illustrating an example of the first image. FIG. 10 is an explanatory diagram illustrating an example of the second image. As shown in FIG. 9, the first image does not include a predetermined icon that the motion thread M has. On the other hand, as shown in FIG. 10, the second image includes a predetermined icon (circular icon in the figure) of the motion thread M. Thus, the first image and the second image are different from each other in the presence or absence of an icon.

  In the present embodiment, when the banknote BL is inserted into the banknote recognition apparatus 10 in the reverse state, the first image includes a predetermined icon of the motion thread M, and the second image includes the motion thread M. This means that the predetermined icon of the is not included. From the above, when the predetermined icon is included in only one of the first image and the second image, it can be specified that the bill BL has the motion thread M.

A-4. Identification of presence / absence of motion thread M FIG. 11 is a flowchart showing a processing procedure for identifying the presence / absence of the motion thread M. In the bill validator 10, after the power is turned on, a process for specifying the motion thread M is executed. Based on the detection result of the insertion detection sensor 20, the control unit 70 determines whether or not the banknote BL has been inserted into the banknote identification device 10 (step S205). When it determines with the banknote BL having been inserted (step S205: YES), the control part 70 rotates the conveyance roller 50, makes the 1st light guide light source 110 and the 2nd light guide light source 120 light, The first line sensor 150 and the second line sensor 160 are driven (step S210). The detailed procedure of each process in step S210 is the same as the procedure described in “A-2. Overall operation of bill validator 10” described above, and detailed description thereof is omitted.

  The optical sensor unit 100 irradiates the bill BL with light and receives the transmitted light transmitted through the bill BL by the line sensor (step S215). The image generation unit 71 generates a first image based on the reception of the first transmitted light by the first line sensor 150 (step S220). The image generation unit 71 generates a second image based on the reception of the second transmitted light by the second line sensor 160 (step S225).

  The pattern identifying unit 72 identifies whether or not the generated first image includes a predetermined icon of the motion thread M (step S230). When it is identified that the predetermined icon is included (step S230: YES), the pattern identification unit 72 determines whether or not the generated second image includes the predetermined icon that the motion thread M has. Is identified (step S235). On the other hand, when it is identified that the generated first image does not include the predetermined icon of the motion thread M (step S230: NO), the pattern identifying unit 72 also generates the generated second image. Is identified whether or not the predetermined icon of the motion thread M is included (step S240).

  If it is determined in step S235 that the predetermined icon is not included (step S235: NO), only one of the first image and the second image includes the predetermined icon. Will be. For this reason, the specific | specification part 73 specifies that the banknote BL has the motion thread | sled M (step S250). Similarly, when it is determined in step S240 that a predetermined icon is included (step S240: YES), the predetermined icon is only displayed in one of the first image and the second image. It will be included. For this reason, the specific | specification part 73 specifies that the banknote BL has the motion thread | sled M (step S250).

  If it is determined in step S235 that the predetermined icon is included (step S235: YES), both the first image and the second image include the predetermined icon. For this reason, specific part 73 specifies that bill BL does not have motion thread M (Step S245). As a case where a predetermined icon is included in both the first image and the second image, the banknote BL does not have the microlens array M2 and the predetermined icon does not have the microlens array M2. The case where it prints on bill BL so that identification is possible is assumed.

  If it is determined in step S240 that the predetermined icon is not included (step S240: NO), neither the first image nor the second image includes the predetermined icon. For this reason, specific part 73 specifies that bill BL does not have motion thread M (Step S255). As a case where the predetermined icon is not included in either the first image or the second image, the bill BL does not have the microlens array M2, and the icon is not printed on the bill BL. Is assumed.

  In the banknote identification device 10 of the present embodiment described above, the banknote BL has the motion thread M when a predetermined icon is included in only one of the first image and the second image. Then, since it identifies, the identification precision of the presence or absence of the motion thread | sled M can be improved. That is, when two images are different from each other depending on the presence or absence of an icon, the bill BL is identified as having a motion thread M. Therefore, compared to the method of comparing the position of the icon in the two images, the motion thread M The presence / absence identification accuracy can be improved.

  Since the bill BL is continuously conveyed at a high speed in the bill identification device 10, it is likely to bend or be displaced. Therefore, in the method of comparing the positions of the icons in the two images, the displacement when the bill BL is conveyed is considered. There is a need to. However, in the banknote identification apparatus 10 of this embodiment, since the presence or absence of the motion sled M is specified based on the clear difference of the presence or absence of an icon, it is not necessary to consider the position shift at the time of conveyance of the banknote BL. For this reason, image processing can be performed easily, and in addition to being able to reduce the load of the banknote identification device 10, the presence or absence of the motion thread M can be quickly identified. In addition, the device configuration can be simplified by using light guides to which diffusers are added as the first light guide light source 110 and the second light guide light source 120. Furthermore, since both the first light guide light source 110 and the second light guide light source 120 emit diffused light, the presence or absence of the motion thread M can be specified regardless of the front and back of the inserted bill BL. it can. That is, the predetermined icon of the motion sled M is included in only one image, regardless of whether the surface having the motion sled M is conveyed vertically upward or when the surface is conveyed vertically downward. The bill BL has the motion sled M.

  Various types of motion thread M are known, such as those in which icons appear to move by tilting the banknote BL, those in which different icons can be seen, and those in which icons appear to float. In the banknote identification device 10 of this embodiment, since the presence or absence of the motion thread M is specified based on the clear difference of the presence or absence of an icon, even if the banknote BL has any type of motion thread M, the motion thread The presence or absence of M can be specified with high accuracy.

B. Comparative Example FIG. 12 is a schematic diagram for explaining an optical path when light is emitted from the point light source 310 toward the bill BL in the comparative example. The arrow in the figure indicates the optical path. The point light source 310 irradiates light on the surface having the motion sled M among the surface of the bill BL. The rod lens array 330 causes the transmitted light that has passed through the bill BL to form an image on the line sensor 350. The light emitted from the point light source 310 and refracted by the microlens array M2 forms an image at a predetermined place in the printed image M1. Therefore, a predetermined icon (circular icon in the figure) is imaged on the line sensor 350 facing the point light source 310. Therefore, the image obtained when the point light source 310 is used to irradiate light on the surface of the banknote BL having the motion sled M always includes a predetermined icon of the motion sled M. In the configuration of the comparative example, when light is irradiated on the surface of the banknote BL opposite to the surface having the motion thread M, the obtained image includes a predetermined icon as in the above-described embodiment. . Therefore, in the configuration of the comparative example, a predetermined icon is included in both the first image and the second image. Here, even when a fake note on which a predetermined icon is printed instead of the motion thread M is used, in the configuration of the comparative example, the predetermined icon is displayed in both the first image and the second image. Will be included. Therefore, in the configuration of the comparative example, there may occur a case where the presence or absence of the motion thread M in the banknote BL cannot be specified.

  On the other hand, according to the banknote identification device 10 in the embodiment described above, the first light guide light source 110 and the first light guide light source 110 both irradiate diffuse light. For this reason, about banknote BL which has the motion thread | sled M, a predetermined | prescribed icon is contained only in one image among a 1st image and a 2nd image as mentioned above. Here, when a counterfeit note in which a circular icon is printed instead of the motion thread M is used, the configuration of the embodiment includes a predetermined icon in both the first image and the second image. . Therefore, according to the banknote identification device 10 of the embodiment, the presence or absence of the motion thread M in the banknote BL can be reliably identified.

C. Modifications Note that the present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of the embodiment.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Further, each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program for the processor to realize each function, or may be realized by a computer outside the apparatus. Information such as programs, tables, and files for realizing each function may be placed in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD. it can.

  Further, the control lines and information lines are those that are considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other. Further, the present invention may include the following specific modifications.

C-1. Modification 1
In the embodiment, the first light guide light source 110 and the second light guide light source 120 are both light sources that irradiate diffused light, but the present invention is not limited to this. The second light guide light source 120 may be a point light source. The optical path in such a configuration will be described below. The light irradiated from the second light guide light source 120 and incident on the bill BL (print image M1) is refracted by the microlens array M2, passes through the second rod lens array 140, and the second line sensor 160. To reach. As the light is refracted by the microlens array M2, a predetermined icon is formed on the second line sensor 160. For this reason, the second image includes a predetermined icon of the motion thread M. Therefore, since the image similar to the 2nd image in embodiment is obtained also by this structure, there exists an effect similar to the banknote identification device 10 of embodiment.

C-2. Modification 2
In the embodiment, the light guide body (the first light guide body light source 110 and the second light guide body light source 120) to which the diffuser is added is used as the light source of the optical sensor unit 100. It is not limited to. As the light source of the optical sensor unit 100, an array light source in which a plurality of point light sources are arranged may be used. In this array light source, the plurality of point light sources may be arranged along a direction intersecting the transport direction (Y-axis direction). With such a configuration, the possibility of specifying the presence or absence of the motion sled M can be improved regardless of the position of the motion sled M on the surface of the bill BL. Further, each of the first light guide light source 110 and the second light guide light source 120 may be a light source including a plurality of light guides. Further, light emitted from one point light source and obtained by diffusing using a lens diffusion plate or the like may be used as the light source of the optical sensor unit 100. In this configuration, one point light source and a lens diffuser plate correspond to the first light source unit and the second light source unit in the claims. That is, generally, you may apply the light source part which irradiates the diffused light to the surface of the banknote BL in the banknote identification device 10 of this invention.

C-3. Modification 3
In the embodiment, the first light guide light source 110 includes the two LEDs 113. However, the first light guide light source 110 may include one LED 113 or three or more LEDs 113. Also good. Similarly, the number of the LEDs 113 included in the second light guide light source 120 may be one, or may be three or more. In the optical sensor unit 100, at least one of the first rod lens array 130 and the second rod lens array 140 may be omitted. Even with such a configuration, the same effects as those of the banknote recognition apparatus 10 of the embodiment can be obtained.

C-4. Modification 4
In the embodiment, the line sensors (the first line sensor 150 and the second line sensor 160) are used as the sensors of the optical sensor unit 100, but the present invention is not limited to this. An area sensor may be provided instead of the line sensor. In addition, it is preferable to use a line sensor from the viewpoint of resolution or the like, and the accuracy of specifying the presence or absence of the motion thread M can be further improved as compared with the case of using an area sensor.

C-5. Modification 5
In the embodiment, each component (light guide light source, rod lens array, line sensor) constituting the optical sensor unit 100 is configured to image the entire surface of the bill BL, but the present invention is limited to this. Not. You may be comprised so that a part including the motion thread | sled M of the banknote BL can be imaged. Further, in the embodiment, each component constituting the optical sensor unit 100 is arranged with the X-axis direction as the longitudinal direction, but it is sufficient that any direction intersecting with the Y-axis direction is arranged as the longitudinal direction. The longitudinal direction of the part may not intersect the Y axis perpendicularly. Furthermore, in the embodiment, each component constituting the optical sensor unit 100 is arranged along the Z axis, but the present invention is not limited to this. As long as each sensor can receive light from each light source, they may be arranged along axes that do not intersect the XY plane perpendicularly. Even with such a configuration, the same effect as that of the banknote recognition apparatus 10 of the embodiment can be obtained.

C-6. Modification 6
In the embodiment, the transport roller 50 is driven by receiving power from the host device (ATM) with the plurality of gears 40. However, the bill recognition device 10 has a power source such as a motor, and the power source. You may drive by. Moreover, although the banknote identification device 10 of the embodiment includes the thickness sensor 80, the thickness sensor 80 may be omitted.

C-7. Modification 7
In the embodiment, the present invention is applied to the banknote identification device 10 whose target is the banknote BL. Instead, the present invention is applied to an apparatus for identifying other arbitrary paper sheets such as securities. Also good.

DESCRIPTION OF SYMBOLS 10 ... Banknote identification apparatus 20 ... Insertion detection sensor 30 ... Conveyance path 40 ... Gear 50 ... Conveyance roller 60 ... Rotation detection part 70 ... Control part 71 ... Image generation part 72 ... Pattern identification part 73 ... Specific | specification part 80 ... Thickness sensor 100 ... Optical sensor unit 101 ... first sensor unit 102 ... second sensor unit 110 ... first light guide light source 111 ... light guide 111t ... convex surface 112 ... diffuse reflection paint 120 ... second light guide light source 130 ... first Rod lens array 140 ... second rod lens array 150 ... first line sensor 160 ... second line sensor 310 ... point light source 330 ... rod lens array 350 ... line sensor BL ... banknote IC ... icon group M ... motion thread M1 ... Printed image M2 ... Micro lens array dd ... Conveying direction dy ... Distance dz ... Distance

Claims (6)

A paper sheet identification device for identifying the presence or absence of a motion thread in a paper sheet,
A first light source unit that irradiates one surface of the surface of the paper sheet with diffused light;
A first sensor facing the first light source unit and receiving first transmitted light emitted from the first light source unit and transmitted through the paper;
A second light source unit for irradiating light to the other surface of the surface of the paper sheet;
A second sensor that receives the second transmitted light that faces the second light source unit and is irradiated from the second light source unit and transmitted through the paper;
An image generation unit that generates a first image based on the first transmitted light and generates a second image based on the second transmitted light;
A pattern identifying unit for identifying whether or not each of the first image and the second image includes a predetermined pattern of the motion thread;
A specifying unit that specifies that the paper sheet has the motion thread when the predetermined pattern is included in only one of the first image and the second image;
A paper sheet identification device. The paper sheet identification device according to claim 1,
The second light source unit emits diffused light,
Paper sheet identification device. The paper sheet identification device according to claim 1 or 2,
The light source unit for irradiating the diffused light includes a light guide to which a diffuser is added.
Paper sheet identification device. It is a paper sheet identification device according to any one of claims 1 to 3,
The light source unit that irradiates the diffused light includes an array light source in which a plurality of point light sources are arranged.
Paper sheet identification device. The paper sheet identification apparatus according to claim 4, further comprising:
A transport unit for transporting the paper sheets in the transport direction;
The plurality of point light sources are arranged side by side along a direction intersecting the transport direction,
Paper sheet identification device. A method for identifying the presence or absence of a motion thread in paper,
(A) irradiating one surface of the surface of the paper with diffused light;
(B) receiving the first transmitted light irradiated in the step (a) and transmitted through the paper sheet;
(C) irradiating light to the other surface of the surface of the paper sheet;
(D) receiving the second transmitted light irradiated in the step (c) and transmitted through the paper sheet;
(E) generating a first image based on reception of the first transmitted light;
(F) generating a second image based on reception of the second transmitted light;
(G) identifying whether each of the first image and the second image includes a predetermined pattern of the motion thread;
(H) specifying that the paper sheet has the motion thread when the predetermined pattern is included in only one of the first image and the second image; ,
A method comprising:

Images