JP6247747B2 - Paper sheet authenticity determination device and paper sheet authenticity determination method - Google Patents

Description

  The present invention relates to a paper sheet authenticity determination device and a paper sheet authenticity determination method for receiving paper sheets such as banknotes, checks, gift certificates, and cash vouchers and determining the authenticity of the paper sheets.

  Conventionally, information on fluorescence intensity during excitation light irradiation of a paper sheet containing a substance having fluorescence and phosphorescence characteristics and information on phosphorescence intensity after stopping the excitation light irradiation are obtained, and the paper sheet is based on the information. There are known techniques for discriminating the type and true / false. For example, Patent Document 1 provides a region where excitation light is irradiated to a paper sheet in a region upstream of a conveyance path for conveying the paper, and the excitation light is blocked downstream of the region. A sensor that receives fluorescence from the paper in the upstream region where the excitation light is irradiated on the paper and a sensor that receives phosphorescence from the paper in the downstream region where the excitation light is blocked. A technique for providing information on fluorescence intensity and phosphorescence intensity of paper sheets is disclosed.

  In the technique disclosed in Patent Document 1, it is necessary to separately provide a sensor that acquires information on fluorescence intensity and a sensor that acquires information on phosphorescence intensity, and the structure of the sensor becomes complicated. However, a technique for acquiring information on fluorescence intensity and information on phosphorescence intensity with the same sensor is also known. For example, in Patent Document 2, a light source that emits excitation light is turned on / off in a short cycle, and fluorescence intensity information is acquired while the light source is turned on. Thus, there is disclosed a technique of acquiring information on fluorescence intensity and information on phosphorescence intensity with the same sensor.

  Further, for example, in Patent Document 3, by acquiring information on fluorescence intensity and information on phosphorescence intensity using a plurality of sensors provided with filters having different wavelength regions to be transmitted, information on intensity for each wavelength range of fluorescence and phosphorescence. A technique of obtaining the above is also disclosed. Substances that exhibit fluorescence and phosphorescence characteristics are known to have different wavelength characteristics of fluorescence and phosphorescence depending on the type of the substance. By detecting these characteristics, more rigorous types of paper sheets and It is possible to perform true / false discrimination.

  In this way, information on the fluorescence intensity during excitation light irradiation of the paper sheet containing the substance having the characteristics of fluorescence and phosphorescence and information on the phosphorescence intensity after stopping the excitation light irradiation are obtained, and based on these information, the paper is obtained. By discriminating between the types of leaves and the authenticity, it is possible to detect counterfeit banknotes and the like that are difficult to distinguish by human eyes.

Japanese Patent No. 5367509 Japanese Patent No. 4048121 Japanese Patent No. 3790931

  However, in the case of forgery after investigating the fluorescence and phosphorescence emission intensity by wavelength of genuine paper sheets in advance, it is counterfeited in authenticity discrimination based on the fluorescence and phosphorescence emission intensity of banknotes. It is also assumed that paper sheets cannot be detected. In addition, when trying to identify the characteristics related to the emission wavelengths of fluorescence and phosphorescence as in Patent Document 3, the characteristics of the substance having the fluorescence and phosphorescence characteristics used for the paper sheets that are subject to authenticity determination It is assumed that a filter corresponding to the above is required and the structure of the sensor becomes complicated.

  In this way, in determining the type and authenticity of paper sheets containing a substance having fluorescence and phosphorescence characteristics, the sensor configuration is simplified to reduce costs, and strict authenticity determination of banknotes is realized. Is an important issue.

  The present invention is to solve the above-described problems of the prior art, and can realize a strict discrimination of banknotes while suppressing costs by simplifying the sensor configuration. It is an object of the present invention to provide a true / false determination apparatus and a paper sheet authenticity determination method.

  In order to solve the above-described problems and achieve the object, the present invention is a paper sheet authenticity determination device that determines the type and / or authenticity of a paper sheet having a characteristic of emitting phosphorescence by irradiation with excitation light. The conveying means for conveying the paper sheet, the excitation light irradiating means for irradiating the excitation light to a small area of the paper sheet during conveyance by the conveying means, and the excitation light irradiating means Phosphorescence intensity acquisition means for irradiating a small area of the paper sheet with the excitation light and acquiring the intensity of the phosphorescence emitted from the small area of the paper sheet after the excitation light irradiation by the excitation light irradiation means is stopped And an attenuation rate indicating a rate of decrease in the phosphorescence intensity of the small area of the paper sheet based on the phosphorescence intensity of the small area of the paper sheet acquired a plurality of times by the phosphorescence intensity acquisition unit. The phosphorescence decay rate calculating means and the transport means. A phosphorescence attenuation rate pattern generation unit that generates a phosphorescence attenuation rate pattern that associates the attenuation rate calculated by the phosphorescence attenuation rate calculation unit with the position of the small region in the paper sheet based on a conveyance state; By comparing the phosphorescence decay rate pattern of the genuine paper sheet thus made and the phosphorescence decay rate pattern of the paper sheet to be discriminated generated by the phosphorescence decay rate pattern generating means, the paper to be discriminated Included is a true / false discriminating means for discriminating whether the leaf is true or false.

  Also, the present invention is the above invention, wherein a plurality of the excitation light irradiation means are arranged in a direction of intersection between a plane parallel to the transport surface of the paper sheet and a surface perpendicular to the transport direction of the paper sheet, The phosphorescence intensity acquisition means is arranged in the same direction as the excitation light irradiation means in the same direction as the excitation light irradiation means.

  Further, the present invention is the above invention, wherein the excitation light irradiating means irradiates the excitation light to the paper sheet, and the excitation light irradiation means and the phosphorescence intensity acquisition means are arranged on the conveyance surface of the paper sheet. It is characterized by being arranged on the opposite side across.

  Further, the present invention is the above invention, wherein the excitation light irradiation means irradiates the excitation light to the paper sheet, and the excitation light irradiation means and the phosphorescence intensity acquisition means are provided on a conveyance surface of the paper sheet. It is characterized by being arranged on the same side.

  Further, the present invention is the above invention, wherein the phosphorescence intensity of the paper sheet acquired by the phosphorescence intensity acquisition unit is determined in the transport direction position of the paper sheet while the paper sheet is transported by the transport unit. A phosphorescence intensity pattern generating means for generating a phosphorescence intensity pattern associated with the above, a phosphorescence intensity pattern of the genuine paper sheet previously generated by the phosphorescence intensity pattern generating means, and a discrimination target generated by the phosphorescence intensity pattern generating means And a second authenticity judging means for judging authenticity of the paper sheet to be discriminated by comparing with the phosphorescence intensity pattern of the paper sheet.

  Further, the present invention is the above invention, wherein in the above invention, the phosphorescence intensity pattern of the genuine paper sheet previously generated by the phosphorescence intensity pattern generation means, and the paper sheet to be discriminated generated by the phosphorescence intensity pattern generation means. It is characterized by further comprising a paper sheet type discriminating means for discriminating the type of the paper sheet to be discriminated by comparing with the phosphorescence intensity pattern.

  Further, the present invention is the above invention, wherein the excitation light irradiating means irradiates excitation light including a wavelength component of 800 nm to 1000 nm, and the phosphorescence intensity acquiring means is light having a wavelength longer than that of visible light and / or excitation light. It is characterized by acquiring the intensity | strength of.

  Further, the present invention is the above invention, wherein the relationship between the conveyance speed of the conveyance unit and the reading region by the phosphorescence intensity acquisition unit is the small region for acquiring the phosphorescence intensity in the region irradiated by the excitation light irradiation unit. The area is 50% or more.

  Further, the present invention provides the transmitted light intensity according to the above invention, wherein the intensity of the transmitted light of the small area of the paper sheet is acquired while the small area of the paper sheet is irradiated with the excitation light by the excitation light irradiation unit. A transmission unit that associates the intensity of the transmitted light of the paper sheet acquired by the transmitted light intensity acquisition unit with a position in the conveyance direction of the paper sheet while the acquisition unit and the paper sheet are transported by the transport unit; Transmitted light intensity pattern generating means for generating a light intensity pattern, the transmitted light intensity pattern of the genuine paper sheet previously generated by the transmitted light intensity pattern generating means, and the discrimination generated by the transmitted light intensity pattern generating means The apparatus further comprises third authenticity determination means for determining authenticity of the paper sheet to be determined by comparing with the transmitted light intensity pattern of the target paper sheet.

  The present invention is also a paper sheet authenticity determination method for determining the type and / or authenticity of a paper sheet having a characteristic of emitting phosphorescence upon irradiation with excitation light, and transports the received paper sheet A transporting step, an excitation light irradiating step for irradiating the small area of the paper sheet with the excitation light during the transporting by the transporting step, and the excitation light irradiating step. A phosphorescence intensity acquisition step for irradiating the region and acquiring the intensity of the phosphorescence emitted from the small region of the paper sheet after stopping the excitation light irradiation by the excitation light irradiation step, and a plurality of phosphorescence intensity acquisition steps. Based on the phosphorescence intensity of the small region of the paper sheet acquired twice, a phosphorescence attenuation rate calculating step for calculating an attenuation factor indicating a rate of decrease in the phosphorescence intensity of the small region of the paper sheet; and Transport A phosphorescence attenuation rate pattern generation step for generating a phosphorescence attenuation rate pattern in which the attenuation rate calculated in the phosphorescence attenuation rate calculation step and the position of the small region in the paper sheet are associated with each other based on the transport state by the A discrimination target by comparing the phosphorescence decay rate pattern of the genuine paper sheet generated in advance with the phosphorescence decay rate pattern of the discrimination target paper sheet generated in the phosphorescence decay rate pattern generation step. And a true / false discrimination step for discriminating whether the paper sheet is true or false.

  According to the present invention, the phosphor sheet is transported, the small area of the paper sheet is irradiated with the excitation light during the transportation, and after the irradiation of the excitation light is stopped, the phosphorescence emitted from the small area of the paper sheet is emitted. Based on the phosphorescence intensity of the small area of the paper sheet acquired multiple times, calculate the attenuation rate indicating the rate of decrease in the phosphorescence intensity of the small area of the paper sheet, and based on the conveyance state A phosphorescence decay rate pattern that associates the phosphorescence decay rate with the position of a small area in the paper sheet is generated, and the phosphor light decay pattern of the genuine paper sheet generated in advance and the phosphorescence of the paper sheet to be discriminated By comparing with the attenuation rate pattern, it is configured to determine the authenticity of the paper sheet to be determined, so it is possible to simplify the sensor configuration and control the cost while reducing the cost and strict authenticity determination of banknotes. Can be realized.

FIG. 1 is an explanatory diagram for explaining an outline of a bill authenticity determination method according to the present embodiment. FIG. 2 is a diagram for explaining the phosphorescent emission characteristics of banknotes in which specific areas are printed using phosphorescent ink. FIG. 3 is a block diagram showing an internal configuration of a bill authenticity discriminating apparatus for discriminating the authenticity of bills according to the present embodiment. FIG. 4 is a diagram for explaining the configuration of the line sensor including the light emitting unit and the light receiving unit illustrated in FIG. 1. FIG. 5 is a diagram for explaining the data configuration of the bill authenticity discriminating apparatus shown in FIG. FIG. 6 is a diagram for explaining the processing timing related to the image acquisition of the banknote of the present embodiment in the banknote authenticity determination device shown in FIG. 3. FIG. 7 is a flowchart showing a processing procedure of image data acquisition processing in the bill authenticity determination device shown in FIG. FIG. 8 is a flowchart showing a processing procedure of bill authenticity discrimination processing in the bill authenticity discriminating apparatus shown in FIG.

  Exemplary embodiments of a paper sheet authenticity determination apparatus and a paper sheet authenticity determination method according to the present invention will be described below in detail with reference to the accompanying drawings. In the embodiment, description will be made using “banknotes” as a representative of “paper sheets”.

  First, the outline | summary of the authenticity determination method of the banknote which concerns on a present Example is demonstrated using FIG. FIG. 1A is a diagram illustrating an outline of the relationship between the structure of a line sensor 120 that acquires an image of a banknote included in the banknote authenticity determination device 100 according to the present embodiment and a banknote that is a target of authenticity determination. . FIG.1 (b) is a figure which shows the example of the information acquired by the line sensor 120 in each area | region of the object area | region divided | segmented into the (mxn) banknote shown in Fig.1 (a). FIG.1 (c) is a figure which shows the production | generation method of the image used for authenticity determination of a banknote based on the acquisition information shown in FIG.1 (b). FIG. 1D is a diagram for explaining the concept of authenticity determination performed using the image data generated in FIG.

  As shown in FIG. 1A, the line sensor 120 is disposed so as to sandwich the banknote conveyance path, and includes a light emitting unit 121 on the upper side of the conveyance path and a light receiving unit 123 on the lower side of the conveyance path. The light emitting unit 121 includes m light emitting units 122 arranged at equal intervals in the y-axis direction. The light emission part 122 can irradiate infrared light with respect to the upper surface of a banknote. The light receiving unit 123 includes m light receiving units 124 arranged at equal intervals in the y-axis direction, and the m light receiving units 124 are arranged at positions corresponding to the m light emitting units 122. In addition, the light receiving unit 124 detects light transmitted through the banknote passing through the conveyance path and light emitted from the banknote.

  The banknote is conveyed in the positive direction of the x axis and acquires information by the line sensor 120 at n positions in the x axis direction while passing through the line sensor 120. As a result, the banknote passing through the line sensor 120 is acquired by the line sensor 120 for every n unit detection areas in the x-axis direction and m in the y-axis direction.

  FIG. 1B is a graph showing the relationship between the received light intensity acquired by the light receiving unit 124 corresponding to the area (x, y) which is one of the unit detection areas shown in FIG. is there. The light emitting unit 121 of the line sensor 120 is turned on at time t0 and turned off at time t2 at every n positions in the x-axis direction of the bill. The light receiving intensity acquired by the light receiving unit 124 is v1 from t0 to t2 when the light emitting unit 122 corresponding to the area (x, y) is turned on, and after the light emitting unit 122 is turned off at t2, the light receiving unit is turned on with time. It shows that the received light intensity acquired at 124 is lowered. The acquisition information corresponding to the area (x, y) includes the received light intensity v1 at t1 as the received light intensity during excitation light irradiation, the received light intensity v3 at t3 as the received light intensity after extinction of the excitation light, and the t4 time The received light intensity v4, the received light intensity v5 at t5, and the received light intensity v6 at t6 are included.

  In FIG. 1C, the excitation intensity is calculated from the received light intensity (v1) during irradiation of the excitation light shown in FIG. 1B and the received intensity (v3, v4, v5, and v6) after the excitation light is extinguished. A method of generating lighting-time image data 132 based on information during lighting, afterglow intensity image data 134 and afterglow decay rate image data 135 based on information after extinction of excitation light will be described.

  The lighting image data 132 is an image composed of (m × n) pixels corresponding to the (m × n) regions of the banknote shown in FIG. 1A, and corresponds to each pixel. It is an image in which the received light intensity v1 at t1, which is the received light intensity during the excitation light irradiation shown in the graph of FIG. 1B in the region, is the pixel value of the corresponding pixel.

  The afterglow intensity image data 134 is an image composed of (m × n) pixels corresponding to the (m × n) regions of the banknote shown in FIG. 1A, and corresponds to each pixel. 1B is an image in which the total value of v3, v4, v5, and v6, which is the received light intensity after excitation light extinction shown in the graph of FIG.

  The afterglow decay rate image data 135 is an image composed of (m × n) pixels corresponding to the (m × n) regions of the banknote shown in FIG. It is an image which makes the attenuation rate of the received light intensity from t3 to t6 after the excitation light extinction shown in the graph of FIG. 1 (b) in the corresponding region the pixel value of the corresponding pixel. The attenuation rate of the received light intensity from t3 to t6 can be calculated by dividing the value obtained by subtracting the received light intensity v6 at t6 from the received light intensity v3 at t3 by the value obtained by subtracting from t6 to t3. it can. Here, four samplings are performed, but the attenuation rate can be obtained by two or more samplings.

  The way in which the afterglow intensity decreases with the passage of time after the excitation light extinction shown in FIG. 1B is different depending on the type of phosphorescent ink contained in the banknote and the amount used. Therefore, even when it is difficult to discriminate the difference only with the received light intensity of phosphorescent ink light, by evaluating the difference in how the afterglow intensity decreases due to the difference in the usage of the phosphorescent ink used for printing the genuine note Therefore, it is possible to determine the authenticity of the banknote more strictly.

  Moreover, the bill authenticity discrimination device 100 is based on the information corresponding to the genuine note acquired by the line sensor 120 for each denomination / direction to be discriminated in advance, as shown in FIG. 1 (b) and FIG. 1 (c). The lighting reference image, the afterglow intensity reference image, and the afterglow attenuation rate reference image created by the same procedure as shown in FIG. At the time of bill authenticity determination processing, as shown in FIG. 1 (d), on-time image data 132, afterglow intensity image data 134 generated based on information on the authenticity determination target banknote acquired by the line sensor 120, and Afterglow decay rate image data 135 is generated, and a lighting reference image, an afterglow intensity reference image, and an afterglow decay rate reference image corresponding to a genuine note included in the discrimination reference data 131 created and stored in advance, By comparing, the authenticity of the banknote is determined.

 Furthermore, in order to receive and evaluate afterglow after the infrared light is extinguished from the region irradiated with infrared light, which is excitation light, at least 50% or more of the region irradiated with infrared light. The afterglow from the region needs to be received by the light receiving sensor. For this purpose, it is necessary to appropriately design the conveyance speed, the light receiving area of the light receiving sensor, and the infrared light irradiation area.

  Thus, using the line sensor 120 which detects the transmitted light from a banknote and the afterglow of the phosphorescence which a banknote light-emits by irradiating excitation light with respect to the banknote which has a characteristic which light-emits phosphorescence by irradiation of excitation light. Based on the lighting-time image data 132 acquired during excitation light irradiation, the afterglow intensity image data 134 generated based on the afterglow intensity after excitation light extinction, and the decay rate of the afterglow intensity after excitation light extinction Evaluation of the similarity between the afterglow decay rate image data 135 generated in this way, the lighting reference image corresponding to each genuine note stored in advance, the afterglow intensity reference image, and the afterglow decay rate reference image Thus, the authenticity determination of the banknote can be realized while simplifying the sensor configuration and suppressing the cost while suppressing the cost.

  Next, the phosphorescent light emission characteristics of banknotes in which specific areas are printed using phosphorescent ink will be described with reference to FIG. The banknotes shown in FIGS. 2A and 2B are examples in which phosphorescent ink is used in a similar region. Moreover, these two banknotes are examples in which the emission intensity of afterglow after the stop of infrared light irradiation is the same, but there is a difference in the attenuation rate.

  The banknote shown in FIG. 2 (a) uses phosphorescent ink in the lower left part of the banknote as shown in FIG. 2 (a). The middle graph in FIG. 2A shows the intensity of afterglow on the scanning line parallel to the x-axis at the position where the y-axis direction applied to the phosphor ink use region shown in FIG. It is a graph. The lower graph in FIG. 2A shows the decay rate of afterglow on the scanning line parallel to the x-axis at the y-axis scanning position in the y-axis direction in the phosphor ink use region shown in FIG. It is the graph which showed.

  In the banknote shown in FIG. 2 (b), phosphor ink is used in the lower left part of the banknote similar to the banknote in FIG. 2 (a) as shown in FIG. 2 (b). The middle graph in FIG. 2B shows the intensity of afterglow on the scanning line parallel to the x-axis at the y-axis scanning position in the phosphor ink-use region shown in FIG. 2B. It is a graph. The lower graph of FIG. 2B shows the decay rate of afterglow on the scanning line parallel to the x-axis at the y-axis scanning position in the phosphor ink usage region shown in FIG. 2B. It is the graph which showed.

  From the middle graphs of FIGS. 2A and 2B, the afterglow detection position is strongly detected in the range of x1 and x2 in the x-axis direction, and the received light intensity of the detected afterglow is detected. 2 (a) and FIG. 2 (b) both have a peak in the vicinity of v1, and there is a high possibility that the banknotes in FIGS. 2 (a) and 2 (b) are determined to have high similarity.

  From the lower graphs of FIGS. 2 (a) and 2 (b), the positions where the afterglow attenuation rate is high are both in the range of x1 and x2 in the x-axis direction, but are similar to each other in FIG. Since the difference between the attenuation rate peak (r1) in a) and the attenuation rate peak (r2) in FIG. 2 (b) is large, the banknotes in FIGS. 2 (a) and 2 (b) have similarities. There is a high possibility of being determined to be low.

  In the present embodiment, the authenticity determination of the banknote is performed using the received light intensity for each afterglow area and the attenuation rate for each afterglow area, as shown in FIG. Authenticity can be determined.

  Next, the internal structure of the banknote authenticity determination apparatus 100 which performs authenticity determination of the banknote which concerns on a present Example is demonstrated. FIG. 3 is a block diagram showing the internal configuration of the bill authenticity determination device 100.

  As illustrated in FIG. 3, the bill authenticity determination device 100 acquires the image information of the banknotes that are attached to the transport unit 110 that transports banknotes one by one and the transport unit 110 and that has been transported by the transport unit 110. A line sensor 120, a storage unit 130, and a control unit 140 are included.

  The storage unit 130 is a storage device composed of a nonvolatile memory or the like. The storage unit 130 includes discrimination reference data 131, lighting image data 132, afterglow sample data 133, afterglow intensity image data 134, and afterglow attenuation rate image data 135.

  The discrimination reference data 131 is data that is stored in advance prior to the bill authenticity discrimination processing, and is reference image data that is used when discriminating the authenticity of a bill conveyed to the bill authenticity discrimination device 100. , And a threshold value for determining the authenticity of the bill of the evaluation value calculated using the reference data.

  The lighting-time image data 132 is data in which the intensity of the transmitted light of the banknote received by the light receiving unit 123 while the light emitting unit 121 is turned on is stored for each unit detection area shown in FIG.

  The afterglow sample data 133 is data in which the intensity of the afterglow of the banknote received by the light receiving unit 123 after the light emitting unit 121 is turned off is stored for each unit detection area shown in FIG. The afterglow sample data 133 is, for example, after the light emitting unit 121 is turned off, at a time t3 elapsed, a time t4 elapsed, a time t5 elapsed, a time t6 elapsed (t3 <t4 <t5 <t6). 4 sample values of afterglow intensity acquired at the four timings are acquired. The number of afterglow samples to be acquired is not limited to 4 samples, and may be 2 samples or 5 samples or more. That is, the afterglow sample data 133 is obtained by performing the sample two or more times at intervals after a predetermined time has elapsed after the lighting unit 121 has stopped lighting.

  The afterglow intensity image data 134 is, for example, data generated from the afterglow sample data 133, and each pixel value is a sum of four sample values acquired at four timings included in the afterglow sample data 133. It is an image as a value. In this embodiment, the pixel value of the afterglow intensity image data 134 is set to the total value of the four sample values acquired at the four timings included in the afterglow sample data 133 as described above, but the present invention is limited to this. It is not a thing. As another example, the pixel value of the afterglow intensity image data 134 may be an average value of four sample values acquired at four timings included in the afterglow sample data 133. Further, for example, the pixel value of the afterglow intensity image data 134 may be any one sample value acquired at four timings included in the afterglow sample data 133.

  The afterglow decay rate image data 135 is data generated from the afterglow sample data 133, and each pixel value is set to t3 when a predetermined time elapses after the light emitting unit 121 of the afterglow sample data 133 is turned off. It is an image that is a value calculated by dividing a value obtained by subtracting a sample value at time t6 after the lighting unit 121 is turned off from a sample value at time, by dividing by (t6-t3). In the present embodiment, the pixel value of the afterglow attenuation rate image data 135 is set as the amount of decrease in the afterglow intensity per time between t3 and t6 after the lighting unit 121 stops lighting. The invention is not limited to this. For example, the afterglow intensity may be reduced per hour based on information on any two time points acquired as the afterglow sample data 133. Further, for example, the ratio of the afterglow intensity at the time t6 after the light emitting unit 121 stops lighting may be the ratio of the afterglow intensity at the time t3 when the predetermined time has elapsed after the light emitting unit 121 stops lighting.

  The control unit 140 is a control unit that controls the entire bill authenticity determination device 100, and includes a conveyance control unit 141, a light emission control unit 142, an image acquisition control unit 143, an afterglow image generation unit 144, a denomination acquisition unit 145, and A true / false determination unit 146 is included. Actually, a program corresponding to this functional unit is stored in a ROM or non-volatile memory (not shown), and this program is loaded into a CPU (Central Processing Unit) and executed to execute the corresponding process. become.

  The conveyance control unit 141 controls the conveyed banknotes to pass through the line sensor 120 at a predetermined conveyance speed. Moreover, authenticity determination is performed based on the information acquired by the line sensor 120 by passing the line sensor 120, and the determination result is sent to the host controller.

  The light emission control unit 142 repeats turning on and off in a predetermined cycle by instructing the light emitting unit 121 of the line sensor 120. In addition, the light emission control unit 142 instructs the light receiving unit 123 to reduce the gain of the circuit for lighting together with the lighting instruction to the light emitting unit 121. In addition, the light emission control unit 142 instructs the light emitting unit 121 to increase the circuit gain for detecting the afterglow to the light receiving unit 123 along with the instruction to turn off the light emitting unit 121.

  When the banknote passes the line sensor 120, the image acquisition control unit 143 writes the information acquired by the light receiving unit 123 at the timing when a predetermined time has elapsed from the start of lighting of the light emitting unit 121 in the lighting image data 132. In addition, the image acquisition control unit 143 writes the sample values acquired by the light receiving unit 123 at four timings after the elapse of a predetermined time from the extinction of the light emitting unit 121 to the afterglow sample data 133. One image of the lighting-time image data 132 and four sample values of the afterglow sample data 133 are scanning lines determined by the lighting cycle of the light emitting unit 121, the conveyance speed of the conveyance unit 110, and the length of the banknote in the conveyance direction, respectively. It is an image having as many pixels as the number obtained by multiplying the number by the number of light receiving units 124 included in the light receiving unit 123.

  The afterglow image generation unit 144 uses the afterglow image data 134 and the afterglow attenuation rate image data based on the four afterglow images included in the afterglow sample data 133 and having different elapsed times from the stop of excitation light irradiation. 135 is generated. Each pixel value of the afterglow intensity image data 134 is a total value of the pixel values of the pixels at the same position in the four afterglow images included in the afterglow sample data 133 and having different elapsed times from the excitation light irradiation stop. is there. In addition, each pixel value of the afterglow attenuation rate image data 135 includes the pixel value of the pixel at the same position in the afterglow image that is included in the afterglow sample data 133 and has the shortest elapsed time from the excitation light irradiation stop, This is a value obtained by dividing the difference between the sample values at the same position in the afterglow image with the longest elapsed time from the stop of excitation light irradiation by the difference in elapsed time.

  The denomination acquiring unit 145 is a processing unit that acquires the denomination of the banknote and the direction of the banknote determined by the denomination identifying unit provided upstream of the conveyance path (not shown).

  The authenticity determination unit 146 determines the reference standard data based on the afterglow intensity image data 134, the afterglow attenuation rate image data 135, and the information on the denomination of the banknote to be determined and the direction of the banknote acquired by the denomination acquisition unit 145. Whether or not the banknote corresponding to the image data acquired by the line sensor 120 by selecting the reference image data for each denomination / direction included in 131 is a genuine note of the denomination / direction acquired by the denomination acquiring unit 145. Is determined.

  Next, the configuration of the line sensor 120 including the light emitting unit 122 and the light receiving unit 124 illustrated in FIG. 1 will be described with reference to FIG. FIG. 4 is a cross-sectional view of the line sensor 120 taken along a plane perpendicular to the bill conveyance direction.

  The line sensor 120 has a light emitting unit 121 on the upper side and a light receiving unit 123 on the lower side across the banknote conveyance path. The light emitting unit 121 includes a plurality of light emitting units 122 arranged at equal intervals. In addition, the light receiving unit 123 includes a light receiving unit 124 at a position corresponding to each light emitting unit 122 of the light emitting unit 121. Each light emitting unit 122 irradiates the bills passing through the conveyance path with excitation light, and the light receiving unit 124 arranged at a position corresponding to each light emitting unit 122 transmits transmitted light accompanying irradiation of excitation light or after irradiation is stopped. Detects afterglow.

  The light emitting unit 122 includes a light emitting unit substrate 122a that controls turning on / off of the light source 122b and adjustment of light emission intensity, a light source 122b such as an LED that emits infrared light, and a transparent member 122d made of transparent glass or resin. Including. The light receiving unit 124 includes a transparent member 124a made of transparent glass or resin, a light receiving sensor 124d that detects light passing through the transparent member 124a, and a light receiving unit substrate 124e that amplifies or digitally converts information detected by the light receiving sensor 124d. Contains. Further, since the difference in light intensity between the transmitted light when the light source 122b is turned on and the afterglow when the light source 122b is turned off is too large, the light receiving unit substrate 124e has a gain (light receiving sensitivity) of the amplification amplifier circuit of the light receiving sensor 124d. The gain of the amplification amplifier circuit can be changed based on an instruction from the control unit 140.

  When the infrared light emitted from the light source 122b of the light emitting unit 122 is applied to the bill that is passing through the conveyance path, the light that has passed through the bill enters the light receiving sensor 124d, and the light receiving sensor 124d detects the transmitted light. Further, after the light source 122b is turned off, the afterglow of the bill enters the light receiving sensor 124d, and the light receiving sensor 124d detects the afterglow. In this way, it is possible to acquire information at the time of lighting when the banknote is irradiated with excitation light and information on the intensity of afterglow after the excitation light irradiation is stopped.

  Here, although the light receiving unit filter 124b and the condensing lens 124c are not described in the above description, the light receiving unit filter 124b and the condensing lens 124c can be provided in the light receiving unit 124 under certain conditions. When measuring phosphorescence, the light source 122b is extinguished, and a filter on the light emission side is unnecessary. The condensing lens 124c can be provided to condense if the excited phosphorescence is weak. Further, when the excited phosphorescence has both a visible light component and an infrared light component, and it is desired to evaluate either one of the light components, a light receiving section filter 124b may be provided.

  Next, the data structure of the banknote authenticity discrimination device 100 shown in FIG. 3 will be described with reference to FIG.

  The discrimination reference data 131 includes authenticity discrimination reference information used in the authenticity discrimination process of the conveyed banknote. The authenticity discrimination reference information includes afterglow intensity image reference information and afterglow attenuation rate image reference information. The afterglow intensity image reference information includes a discrimination threshold value and reference image data for each denomination and direction. The reference image data is afterglow intensity image data 134 acquired using a genuine note. Further, the determination threshold value is an evaluation value indicating the similarity between two images calculated from the afterglow intensity image data 134 of the conveyed banknote and the reference image data, and the conveyed banknote is determined to be a genuine note of the denomination. Indicates the lower limit.

  The afterglow attenuation rate image reference information includes a determination threshold value and reference image data for each denomination and direction. The reference image data is afterglow attenuation rate image data 135 acquired using a genuine note. The discrimination threshold is an evaluation value indicating the similarity between two images calculated from the afterglow decay rate image data 135 and the reference image data of the conveyed banknote, and the conveyed banknote is determined to be a genuine note of the denomination. Indicates the lower limit value.

  The example of the discrimination | determination reference | standard data 131 of FIG. 5 is shown. The afterglow intensity image reference information of the afterglow intensity image reference information with respect to the A direction of the denomination 1 is “v11A” and the afterglow intensity image data 134 serving as a reference for the A direction of the denomination 1 of the genuine note is provided as reference image data. , The true / false discrimination threshold for the B direction of the denomination 1 is “v11B”, and the afterglow intensity image data 134 serving as the reference for the B direction of the genuine denomination 1 is included as the reference image data. The true / false discrimination threshold for the direction is “v12A”, and the afterglow intensity image data 134 is used as the reference for the A direction of the genuine note denomination 2 as the reference image data. It shows that the threshold value is “v13A” and the afterglow intensity image data 134 that is the reference in the A direction of the genuine denomination 3 is used as the reference image data. In addition, the afterglow attenuation rate image data used as the reference in the A direction of the genuine money type 1 as the reference image data when the true / false discrimination threshold for the A direction of the money type 1 of the afterglow attenuation rate image reference information is “v21A”. 135, and the afterglow attenuation which becomes the reference in the B direction of the genuine money type 1 as the reference image data when the true / false discrimination threshold for the B direction of the money type 1 of the afterglow attenuation rate image reference information is “v21B”. The afterglow attenuation rate image data 135 serving as the reference in the A direction of the genuine money type 2 is used as the reference image data with the authenticity determination threshold value “v22A” for the A direction of the money type 2. And the afterglow attenuation rate image data 135 which is the reference in the A direction of the genuine note denomination 3 is used as the reference image data with the true / false discrimination threshold for the A direction of the denomination 3 being “v23A”. Is shown. Here, four directions in the transport direction are expressed as an A direction, a B direction, a C direction, and a D direction.

  The afterglow sample data 133 is four sample data acquired at four timings with different elapsed times from the excitation light irradiation stop. Data of afterglow sample value 1, afterglow sample value 2, afterglow sample value 3, and afterglow sample value 4 are included in ascending order of elapsed time from the stop of excitation light irradiation.

  Next, the processing timing concerning the image acquisition of the banknote of a present Example in the banknote authenticity determination apparatus 100 shown in FIG. 3 is demonstrated using FIG. FIG. 6 is a diagram illustrating the gain switching of the amplification circuit of the light receiving unit 123 and the image data acquisition timing by the light receiving unit 123 in one cycle of turning on and off the light emitting unit 121 of the line sensor 120.

  As shown in FIG. 6, the light emitting unit 121 operates as one cycle from turning on at t1, turning off at t4, and turning on again at t13. The length of one cycle is fixed at L1, and the length of the lighting time from the start of lighting until turning it off is L2, and the length of the turning-off time from turning off the light to turning on Is L3. Times L2 and L3 may be the same length. The gain of the amplifier circuit of the light receiving unit 123 is switched in synchronization with the lighting and extinguishing of the light emitting unit 121, and the gain of the amplifier circuit of the light receiving unit 123 is synchronized with the lighting of the light emitting unit 121 at t1 and t13. Lower. Further, the gain of the amplifier circuit of the light receiving unit 123 is increased in synchronization with the light emitting unit 121 being turned off at t4.

  Further, information detected by the light receiving unit 123 is part of the lighting-time image data 132 from t2 when the predetermined time (L4) has elapsed from the lighting timing (t1) to t3 within the predetermined time (L6). Import as content. Data corresponding to a lighting image of an area on one scanning line perpendicular to the banknote transport direction is acquired by capturing information once.

  Further, the information detected by the light receiving unit 123 from the time t5 when the predetermined time (L5) has elapsed from the timing of turning off (t4) to the time t6 within the predetermined time (L6) is the afterglow of the afterglow sample data 133. Capture as part of sample value 1. In addition, the information detected by the light receiving unit 123 between the time t7 when the predetermined time (L7) has elapsed from the time t6 and the time t8 within the predetermined time (L6) is one of the afterglow sample values 2 of the afterglow sample data 133. Import as part contents. Further, the information detected by the light receiving unit 123 is stored in the afterglow sample value 133 of the afterglow sample data 133 from t9 when the predetermined time (L7) has elapsed from t8 to t10 within the predetermined time (L6). Import as part contents. Further, the information detected by the light receiving unit 123 is stored in the afterglow sample value 4 of the afterglow sample data 133 from t11 when the predetermined time (L7) has elapsed from t10 to t12 within the predetermined time (L6). Import as part contents.

  Next, the processing procedure of the image data acquisition process in the banknote authenticity determination device 100 shown in FIG. 3 will be described. FIG. 7 is a flowchart showing a processing procedure of image data acquisition processing in the bill authenticity determination device 100.

  It is detected whether or not the banknote transported by the transport unit 110 has arrived at the banknote image reading start position (step S101). When it is not detected that the banknote has arrived at the reading start position of the banknote image (step S101; No), the process continues to wait until the arrival is detected. If the arrival of the banknote is detected (step S101; Yes), the image acquisition control unit 143 turns on the image data 132 at the time of lighting, the afterglow sample data 133, the afterglow intensity image data 134, and the afterglow attenuation rate image data 135. A preparation process for obtaining an image of the conveyed banknote is performed (step S102).

  In addition, the light emission control unit 142 instructs to decrease the gain of the amplification circuit of the light receiving unit 123 of the line sensor 120 (Step S103), and instructs the light emitting unit 121 of the line sensor 120 to turn on (Step S104). Next, the image acquisition control unit 143 determines whether or not it is the acquisition timing of the lighting-time image data 132 (step S105), and when it is the acquisition timing of the lighting-time image data 132 (step S105: Yes). The information detected by the light receiving unit 123 is taken in as part of the contents of the lighting-time image data 132 (step S106). If it is not the timing for obtaining the lighting-time image data 132 (step S105: No), the process returns to step S105 to wait for the timing for obtaining the lighting-time image data 132.

  Next, the light emission control unit 142 determines whether or not it is the timing for turning off the light emitting unit 121 (step S107). When the timing for turning off the light emitting unit 121 is reached (step S107; Yes), The light emitting unit 121 of the line sensor 120 is instructed to turn off (step S108), and the instruction to increase the gain of the amplifier circuit of the light receiving unit 123 of the line sensor 120 is issued (step S109). When it is not the timing for turning off the light emitting unit 121 (step S107; No), the process returns to step S107 to wait for the timing for turning off the light emitting unit 121.

  Next, the image acquisition control unit 143 determines whether it is the acquisition timing of the afterglow sample data 133 (step S110), and when it is not yet the acquisition timing of the afterglow sample data 133 (step S110; No). In step S110, the process waits for the afterglow sample data 133 acquisition timing. If it is time to acquire the afterglow sample data 133 (step S110; Yes), the information detected by the light receiving unit 123 is captured as a part of the afterglow sample data 133 (step S111). As shown in FIG. 6, the afterglow image acquisition timing is four times while the light emitting unit 121 is turned on and off during one cycle, and the afterglow sample data 1 to 1 of the afterglow sample data 133 depends on the acquisition timing. 4 is determined as the data to be captured.

  Next, it is determined whether or not four sample values have been acquired at the acquisition timing of four afterglow sample values within one cycle of turning on / off the light emitting unit 121 (step S112), and still acquired. If there is an afterglow image that has not been completed (step S112; No), the process returns to step S110 to wait for acquisition timing of an unacquired afterglow sample value. In addition, when the information for the four sample values at the acquisition timing of the four afterglow sample values has already been acquired (step S112; Yes), the afterglow image generation unit 144 performs the process from step S110 to step 112 immediately before. Based on the acquired afterglow sample data 133, the corresponding pixel value of the afterglow intensity image data 134 is calculated, and the afterglow intensity image data 134 is updated with the calculated content (step S113). Further, the afterglow image generation unit 144 calculates the corresponding pixel value of the afterglow attenuation rate image data 135 based on the afterglow sample data 133 acquired in the immediately preceding step S110 to step 112, and the calculated content. Afterglow decay rate image data 135 is updated (step S114).

  Next, the image acquisition control unit 143 determines whether or not the banknote has passed the line sensor 120 (step S115), and when the banknote has not yet passed the line sensor 120 (step S115; No). Returns to step S103. Moreover, a process is complete | finished when a banknote has already passed the line sensor 120 (step S115; Yes).

  Next, a processing procedure of bill authenticity discrimination processing in the bill authenticity discriminating apparatus 100 shown in FIG. 3 will be described. FIG. 8 is a flowchart showing a processing procedure of bill authenticity determination processing in the bill authenticity determination device 100.

  The bill authenticity determination processing shown in FIG. 8 operates following the bill image data acquisition processing shown in FIG. The denomination acquiring unit 145 acquires information on the denomination of the banknote and the direction of the banknote determined by the denomination identifying unit provided in the upstream portion of the conveyance path (step S201).

  When the denomination / direction information can be acquired in step S201 (step S202; Yes), the authenticity determination unit 146 performs the afterglow intensity image reference information step of the afterglow intensity image data 134 and the determination reference data 131. An evaluation value indicating the similarity between the two images is calculated from the reference image data corresponding to the denomination and direction acquired in S201 (step S203). The authenticity determination unit 146 compares the evaluation value calculated in step S203 with the determination threshold corresponding to the denomination / direction acquired in step S201 of the afterglow intensity image reference information of the determination reference data 131 ( If the evaluation value calculated in step S204 is equal to or greater than the determination threshold (step S204; Yes), the process proceeds to step 205. Here, a correlation coefficient can be used as an example of the evaluation value.

  The authenticity determination unit 146 uses the afterglow decay rate image data 135 and the reference image data corresponding to the denomination and direction acquired in step S201 of the afterglow decay rate image reference information of the discrimination reference data 131, to determine the two An evaluation value indicating the similarity of images is calculated (step S205). The authenticity determination unit 146 compares the evaluation value calculated in step S205 with the determination threshold corresponding to the denomination / direction acquired in step S201 of the afterglow attenuation rate image reference information of the determination reference data 131. (Step S206) When the evaluation value calculated in Step S205 is equal to or greater than the determination threshold value (Step S206; Yes), it is determined that the banknote for the image acquired by the line sensor 120 is a genuine note ( Step S207) and the process is terminated.

  If the evaluation value calculated in step S205 is less than the discrimination threshold for this (step S206; No), it is determined that the banknote for the image acquired by the line sensor 120 is a fake note (step S208), and processing is performed. Exit. Even when the evaluation value calculated in step 203 is less than the discrimination threshold for this (step S204; No), it is determined that the banknote for the image acquired by the line sensor 120 is a fake note (step S208), and processing is performed. Exit. In addition, even when the denomination / direction information cannot be acquired in step S201 (step S202; No), the banknote corresponding to the image acquired by the line sensor 120 is determined to be a fake ticket (step S208) and processed. Exit.

  As another example, in step S201, the denomination of the denomination is determined based on the transmitted infrared light image data stored in the lighting-time image data 132 and the denomination determination reference transmission infrared light data stored in advance in the determination reference data 131. It is also possible to perform identification.

  As described above, in this embodiment, the banknotes having the characteristic of emitting phosphorescence by the excitation light irradiation are irradiated with the excitation light to detect the transmitted light from the banknote and the phosphorescence afterglow emitted from the banknote. The afterglow intensity image data 134 generated based on the afterglow intensity after the excitation light extinguishes using the line sensor 120 and the afterglow attenuation rate image generated based on the decay rate of the afterglow intensity after the excitation light extinction. Since it is configured to determine the authenticity of the banknote by evaluating the similarity between the data 135 and the afterglow intensity reference image corresponding to the genuine note stored in advance and the afterglow attenuation rate reference image, respectively. By making the sensor configuration simple, it is possible to realize strict bill authenticity discrimination while suppressing costs.

Moreover, denomination identification can also be performed by acquiring the lighting-time image data 132 acquired during infrared light irradiation. Further, since the transmission infrared image data, the afterglow intensity image and the afterglow attenuation rate image of the same location of the banknote can be acquired, the position on the banknote is specified by the transmission infrared image data, and the residual corresponding to the specified position is determined. Since the light intensity image value and the afterglow decay rate image value can be evaluated, the authenticity determination can be made precise, and the authenticity determination capability for counterfeit tickets that have been cut and pasted so as to separate the phosphorescent ink area is increased. be able to.

  In addition, although the above-mentioned Example demonstrated the example which performs the authenticity discrimination | determination of the banknote which has the characteristic of exciting with infrared light and phosphorescent-emitting in the wavelength of an infrared region, this invention is limited to this. It is not a thing. The existence of ink that emits phosphorescence with visible light or ultraviolet light is generally well known, and it is possible to use visible light or ultraviolet light instead of infrared light. For example, a line sensor that can detect visible light by irradiating with ultraviolet light should be adopted as a line sensor for banknotes having a feature of being excited by ultraviolet light and emitting phosphorescence at a wavelength in the visible light region. It becomes. Also, unlike infrared light that easily passes through paper, ultraviolet light is difficult to pass through paper, so line sensors that detect visible light by irradiating ultraviolet light irradiate ultraviolet light. In many cases, the reflection type line sensor detects the reflected light of the surface to be reflected. In the present embodiment, the transmission type sensor has been described. However, as the reflection type sensor, the light emitting unit and the light receiving unit can be installed on the same surface of the bill conveyance path. Note that the structure of the transmission sensor or the reflection sensor can be selected based on whether the wavelength used as the excitation light is infrared light, visible light, or ultraviolet light. However, considering whether the wavelength is long or short, whether the reflective sensor is superior or the transmissive sensor is superior is to be studied at the design site.

  In the above-described embodiment, the image data of the entire surface of the paper sheet is acquired by the line sensor 120, and the denomination and authenticity determination are performed based on the image data of the entire surface of the paper sheet. However, the present invention is not limited to this. For example, in an apparatus for paper sheets that can discriminate the denomination and authenticity in a specific area of the paper sheet, only the image data of the specific area is acquired instead of the entire surface of the paper sheet. In this way, the denomination or authenticity may be determined by comparison with a reference image in a specific area.

  In addition, each configuration illustrated in the above-described embodiments is functionally schematic and does not necessarily need to be physically configured as illustrated. That is, the form of distribution / integration of each device is not limited to that shown in the figure, and all or a part thereof may be functionally or physically distributed / integrated in an arbitrary unit according to various loads or usage conditions. Can be configured.

  As described above, the paper sheet authenticity determination device and the paper sheet authenticity determination method according to the present invention realize strict determination of the authenticity of banknotes while suppressing the cost by simplifying the sensor configuration. Suitable for that.

DESCRIPTION OF SYMBOLS 100 Banknote authenticity identification apparatus 110 Conveyance part 120 Line sensor 121 Light emission unit 122 Light emission part 122a Light emission part board | substrate 122b Light source 122d, 124a Transparent member 123 Light reception unit 124 Light reception part 124b Light reception part filter 124c Condensing lens 124d Light reception sensor 124e Light reception part board | substrate DESCRIPTION OF SYMBOLS 130 Memory | storage part 131 Discrimination reference data 132 Image data at the time of lighting 133 Afterglow sample data 134 Afterglow intensity image data 135 Afterglow attenuation rate image data 140 Control part 141 Transport control part 142 Light emission control part 143 Image acquisition control part 144 Afterglow image Generation unit 145 Denomination acquisition unit 146 Authenticity discrimination unit

Claims (10)

A paper sheet true / false discriminating device for discriminating the type and / or authenticity of paper sheets having the property of emitting phosphorescence upon irradiation with excitation light,
Conveying means for conveying the paper sheet;
Excitation light irradiation means for irradiating the excitation light to a small area of the paper sheet during conveyance by the conveyance means;
The excitation light irradiation means irradiates the excitation light to a small area of the paper sheet, and the intensity of the phosphorescence emitted from the small area of the paper sheet after the excitation light irradiation by the excitation light irradiation means is stopped. Phosphorescence intensity acquisition means for acquiring
Phosphorescence for calculating an attenuation rate indicating a rate of decrease in the phosphorescence intensity of the small area of the paper sheet based on the phosphorescence intensity of the small area of the paper sheet acquired a plurality of times by the phosphorescence intensity acquisition unit An attenuation rate calculating means;
A phosphorescence attenuation rate pattern generating unit that generates a phosphorescence attenuation rate pattern in which the attenuation rate calculated by the phosphorescence attenuation rate calculating unit and the position of the small region in the paper sheet are associated with each other based on a conveyance state by the conveyance unit. When,
By comparing the phosphorescence decay rate pattern of the genuine paper sheet generated in advance with the phosphorescence decay rate pattern of the paper sheet to be identified generated by the phosphorescence decay rate pattern generation unit, A paper sheet authenticity judging device comprising: authenticity judging means for judging authenticity of the paper sheets. A plurality of the excitation light irradiating means are arranged in a direction of an intersection line of a surface parallel to the transport surface of the paper sheet and a surface perpendicular to the transport direction of the paper sheet,
2. The paper sheet authenticity determination device according to claim 1, wherein the phosphorescence intensity acquisition unit is arranged in the same direction as the excitation light irradiation unit in the same direction as the excitation light irradiation unit. Phosphorescence that generates a phosphorescence intensity pattern in which the phosphorescence intensity of the paper sheet acquired by the phosphorescence intensity acquisition means is associated with a position in the conveyance direction of the paper sheet while the paper sheet is conveyed by the conveyance means. Intensity pattern generating means;
By comparing the phosphorescence intensity pattern of the genuine paper sheet previously generated by the phosphorescence intensity pattern generation means and the phosphorescence intensity pattern of the paper sheet to be determined generated by the phosphorescence intensity pattern generation means, paper sheet authenticity discrimination apparatus according a second further comprising a and authenticity discrimination means for discriminating the authenticity of the paper sheet of the determination target to claim 1 or 2, characterized in. By comparing the phosphorescence intensity pattern of the genuine paper sheet previously generated by the phosphorescence intensity pattern generation means and the phosphorescence intensity pattern of the paper sheet to be determined generated by the phosphorescence intensity pattern generation means, 4. The paper sheet authenticity discriminating apparatus according to claim 3 , further comprising paper sheet type discriminating means for discriminating the type of the paper sheet to be discriminated. The excitation light irradiation means irradiates excitation light including a wavelength component of 800 nm to 1000 nm,
The paper sheet authenticity determination device according to any one of claims 1 to 4 , wherein the phosphorescence intensity acquisition unit acquires the intensity of light having a wavelength longer than that of visible light and / or excitation light. The relationship between the conveyance speed of the conveyance means and the reading area by the phosphorescence intensity acquisition means is such that, among the areas irradiated by the excitation light irradiation means, the small area for acquiring the phosphorescence intensity is 50% or more. The paper sheet authenticity discrimination device according to any one of claims 1 to 5 . The excitation light irradiation means irradiates the paper sheet with the excitation light,
The paper sheet according to any one of claims 1 to 6, wherein the excitation light irradiation unit and the phosphorescence intensity acquisition unit are disposed on opposite sides of the conveyance surface of the paper sheet. Authenticity discrimination device. Transmitted light intensity acquisition means for acquiring the intensity of transmitted light of the small area of the paper sheet during irradiation of the excitation light by the excitation light irradiation means on the small area of the paper sheet;
A transmitted light intensity pattern in which the transmitted light intensity of the paper sheet acquired by the transmitted light intensity acquisition unit is associated with the position in the transport direction of the paper sheet while the paper sheet is transported by the transport unit. A transmitted light intensity pattern generating means for generating;
Comparing the transmitted light intensity pattern of the genuine paper sheet previously generated by the transmitted light intensity pattern generating means with the transmitted light intensity pattern of the discrimination target sheet generated by the transmitted light intensity pattern generating means The paper sheet authenticity determination device according to claim 7 , further comprising: third authenticity determination means for determining authenticity of the paper sheet to be determined. The excitation light irradiation means irradiates the paper sheet with the excitation light,
The paper sheet according to any one of claims 1 to 6, wherein the excitation light irradiation unit and the phosphorescence intensity acquisition unit are disposed on the same side with respect to a transport surface of the paper sheet. Authenticity discrimination device. A paper sheet authenticity determination method for determining the type and / or authenticity of a paper sheet that has the property of emitting phosphorescence upon irradiation with excitation light,
A transport step for transporting the received paper sheet;
An excitation light irradiation step of irradiating the excitation light to a small region of the paper sheet during conveyance by the conveyance step;
The excitation light irradiation step irradiates the excitation light to a small area of the paper sheet, and the intensity of the phosphorescence emitted from the small area of the paper sheet after the excitation light irradiation by the excitation light irradiation step is stopped. Obtaining a phosphorescence intensity obtaining step;
Phosphorescence for calculating an attenuation rate indicating a rate of decrease in the phosphorescence intensity of the small area of the paper sheet based on the phosphorescence intensity of the small area of the paper sheet acquired a plurality of times by the phosphorescence intensity acquisition step. An attenuation rate calculating step;
A phosphorescence attenuation rate pattern generation step for generating a phosphorescence attenuation rate pattern in which the attenuation rate calculated in the phosphorescence attenuation rate calculation step and the position of the small region in the paper sheet are associated with each other based on the conveyance state in the conveyance step. When,
By comparing the phosphorescence decay rate pattern of the genuine paper sheet generated in advance with the phosphorescence decay rate pattern of the paper sheet to be identified generated in the phosphorescence decay rate pattern generation step, A paper sheet authenticity determination method, comprising: a true / false determination step for determining authenticity of the paper sheet.

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