JP2007179323A - Paper sheet discriminating device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper sheet identification device and method, for accurately discriminating a surface copy forged paper sheet pasted with a copy image or a forged paper sheet having a watermark with writing. <P>SOLUTION: A least squares method is applied to reflection light data of a watermark area acquired from reflection light of the watermark area of a paper sheet to calculated a linear approximate line, an area formed between the calculated linear approximate line and a reflection light curve formed by the reflection light data is calculated, and it is discriminated whether or not the paper sheet is the surface copy forged paper sheet pasted with the copy image or the forged paper sheet having the watermark. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a paper sheet identification apparatus and method for identifying paper sheets such as banknotes having a watermark area in which a watermark pattern is formed.

  Recently, in the identification of paper sheets such as banknotes, focusing on the feature amount of the watermark area where the watermark pattern of the paper sheet is formed, the type, authenticity, etc. of the paper sheet are identified from the feature amount. Various techniques have been proposed.

  For example, in Patent Document 1, a transmissive optical sensor is scanned on a reading line of a target banknote and irradiated with light, a transmitted light quantity pattern from the banknote is obtained, and a transmitted light quantity pattern corresponding to a watermark pattern portion is represented by a watermark pattern. By checking with the maximum value of the transmitted light amount pattern corresponding to the normal pattern part other than the above, it is checked whether or not the target banknote has a watermark pattern. A bill recognition device and a recognition method capable of authenticity determination are disclosed.

In Patent Document 2, the authenticity of a banknote is identified by reading the watermark pattern of the banknote with two optical reading means using transmitted light and reflected light, respectively, and comparing both read data. An authenticity identification device for a bill or the like is disclosed.
JP 2003-187291 A JP-A-6-203244

  However, since the thing of patent document 1 investigates whether there is a watermark pattern using a transmissive optical sensor, for example, a genuine banknote was copied using a copy machine, and the copy image was pasted. A surface copy counterfeit banknote or a written counterfeit banknote in which a pseudo watermark pattern is formed by writing on a watermark portion cannot be identified.

  Moreover, in the thing of patent document 2, the watermark pattern of a banknote is read with two optical reading means using transmitted light and reflected light, respectively, and the said surface copy banknote and the said written forged banknote are compared. However, if the target banknote is curved or flutters in the conveyance path, the reflected light reading pattern will be disturbed, and the surface copy banknote and the written counterfeit banknote will be May become unidentifiable.

  In addition, if the banknote has a fold or the like, the waveform of the reflected light data may change even in the watermark region, and it may not be possible to accurately identify the surface copy forged paper sheet or the written counterfeit paper sheet.

  Accordingly, the present invention provides a paper sheet identification apparatus and method that can accurately identify a surface copy counterfeit paper sheet on which a copy image is pasted or a counterfeit paper sheet that has been written on a watermark. The purpose is to do.

  It is another object of the present invention to provide a paper sheet identification apparatus and method that can accurately identify a paper sheet even if the paper sheet to be identified has a crease or the like.

  In order to achieve the above object, the invention according to claim 1 is a paper sheet identification device for identifying a paper sheet having a watermark area in which a watermark pattern is formed, from reflected light of the watermark area of the paper sheet. Reflected light data acquisition means for acquiring reflected light data of the watermark area, calculation means for calculating a linear approximation line from the reflected light data acquired by the reflected light data acquisition means, and a linear approximation line calculated by the calculation means; An area calculating unit that calculates an area formed between the reflected light data and the reflected light curve; and a determining unit that determines the paper sheet based on the area calculated by the area calculating unit. It is characterized by.

  According to a second aspect of the present invention, in the first aspect of the present invention, the calculating means calculates the linear approximation line by applying a least square method to the reflected light data.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the discriminating means is an authentic paper sheet when the sum of the areas calculated by the area calculating means is smaller than a predetermined threshold value set in advance. It is characterized in that it is present.

  According to a fourth aspect of the present invention, there is provided a paper sheet identification apparatus for identifying a paper sheet having a watermark area in which a watermark pattern is formed, and transmitting the watermark area from the transmitted light of the watermark area of the paper sheet. Obtained by transmitted light data obtaining means for obtaining optical data, reflected light data obtaining means for obtaining reflected light data of the watermark area from reflected light of the watermark area of the paper sheet, and obtained by the transmitted light data obtaining means Extraction means for extracting data of a portion where the peak positions match between the transmitted light data and the reflected light data acquired by the reflected light data acquisition means, and the data extracted by the extraction means is a scratch or fold of the paper sheet Data correction means for removing each of the transmitted light data and the reflected light data as partial data, and the transmitted light data and the reflected light data corrected by the data correction means. Characterized by comprising an identification means that performs identification of the paper sheet based on the data.

  According to a fifth aspect of the present invention, in the invention of the fourth aspect, the identification means calculates a linear approximation line from the reflected light data corrected by the data correction means, and the linear approximation calculated by the calculation means. Area calculating means for calculating an area formed between the line and the reflected light curve formed by the reflected light data corrected by the data correcting means, and determining the paper sheet based on the area calculated by the area calculating means. And a discriminating means for performing the operation.

  According to a sixth aspect of the present invention, there is provided a paper sheet identification apparatus for identifying a paper sheet having a watermark area in which a watermark pattern is formed, and transmitting the watermark area from the transmitted light of the watermark area of the paper sheet. Transmitted light data acquisition means for acquiring optical data; first reflected light data acquisition means for acquiring first reflected light data of the watermark area from the reflected light of the surface of the watermark area of the paper; and Second reflected light data acquisition means for acquiring second reflected light data of the watermark area from reflected light on the back surface of the watermark area of the paper sheet; transmitted light data acquired by the transmitted light data acquisition means; Extraction for extracting data of a portion where the peak positions of the first reflected light data acquired by the first reflected light data acquiring means and the second reflected light data acquired by the second reflected light data acquiring means match. Means and said extraction Data correction means for removing data from the transmitted light data, the first reflected light data, and the second reflected light data, assuming that the data extracted by the means is data on the scratches or creases in the paper sheet; And identifying means for identifying the paper sheet based on the transmitted light data, the first reflected light data, and the second reflected light data corrected by the data correcting means.

  According to a seventh aspect of the present invention, there is provided a paper sheet identification method for identifying a paper sheet having a watermark area in which a watermark pattern is formed, and the reflection of the watermark area from the reflected light of the watermark area of the paper sheet. Optical data is acquired by reflected light data acquisition means, a linear approximation line is calculated by the calculation means from the reflected light data acquired by the reflected light data acquisition means, and the linear approximation line calculated by the calculation means and the reflected light data are An area formed between the reflected light curve to be formed is calculated by an area calculating unit, and the paper sheet is determined by the determining unit based on the area calculated by the area calculating unit.

  The invention according to claim 8 is a paper sheet identification method for identifying a paper sheet having a watermark area in which a watermark pattern is formed. In the paper sheet identification method, transmission of the watermark area from the transmitted light of the watermark area of the paper sheet is performed. Optical data is acquired by transmitted light data acquisition means, reflected light data of the watermark area is acquired by reflected light data acquisition means from reflected light of the watermark area of the paper sheet, and acquired by the transmitted light data acquisition means The extracted data is extracted by the extracting means in the portion where the peak position is the same between the transmitted light data and the reflected light data acquired by the reflected light data acquiring means, and the data extracted by the extracting means is a scratch or fold of the paper sheet The data correction means corrects the data to be removed from the transmitted light data and the reflected light data as being partial data, and the data correction means corrects the data. And performing by the identification means the identity of the over light data and based on the reflected light data the paper sheet.

  The invention according to claim 9 is a paper sheet identification method for identifying a paper sheet having a watermark area in which a watermark pattern is formed. The optical data is acquired by transmitted light data acquisition means, the first reflected light data of the watermark area is acquired by the first reflected light data acquisition means from the reflected light of the surface of the watermark area of the paper sheet, The second reflected light data of the watermark area is acquired by the second reflected light data acquiring means from the reflected light of the back surface of the watermark area of the paper sheet, and the transmitted light data acquired by the transmitted light data acquiring means and the The extraction means extracts data of the portion where the peak positions of the first reflected light data acquired by the first reflected light data acquisition means and the second reflected light data acquired by the second reflected light data acquisition means match. Extract The data extracted by the extracting means is data of scratches or creases on the paper sheet, and data correction is performed to remove from the transmitted light data, the first reflected light data, and the second reflected light data, respectively. The paper sheet is identified by the identifying means based on the transmitted light data, the first reflected light data, and the second reflected light data corrected by the data correcting means.

  According to the present invention, the reflected light data of the watermark area is acquired from the reflected light of the watermark area of the paper sheet, the linear approximate line is calculated from the acquired reflected light data, and the calculated linear approximate line and the reflected light are calculated. Since the area formed between the reflected light curve formed by the data is calculated and the paper sheet is determined based on the calculated area, the identification target paper sheet is curved, fluttered during conveyance, etc. Therefore, it is possible to reliably identify a surface copy forged paper sheet on which a copy image is pasted or a forged paper sheet in which a watermark is written.

  In addition, according to the present invention, the transmitted light data in the watermark area of the paper sheet and the reflected light data or the data whose peak positions match between the reflected light data on the front and back of the paper sheet are transmitted as the data of the flaw or crease. Since it is configured to be removed from the optical data and reflected light data, it is possible to accurately identify the paper sheet without being affected by scratches or folds.

  Hereinafter, embodiments of a paper sheet identification apparatus and method according to the present invention will be described in detail with reference to the accompanying drawings.

  Fig.1 (a) is a figure which shows schematic structure of the banknote identification device of Example 1 comprised by applying this invention.

  In FIG. 1 (a), the banknote recognition apparatus 100 identifies the banknote 30 conveyed on the conveyance belt 20 driven by the conveyance rollers 10a and 10b, and along the conveyance belt 20, FIG. (B) The reflected light data acquisition part 40 which consists of the light emission part 40a and the reflected light data reading part 40b which acquire the reflected light data of the watermark area | region 30a of the banknote 30, and the light emission part which acquires the transmitted light data of the watermark area | region 30a A transmitted light data acquisition unit 50 including a transmission light data reading unit 50b and 50a is provided.

  The reflected light data acquisition unit 40 and the transmitted light data acquisition unit 50 respectively acquire the reflected light data and the transmitted light data of the watermark region 30a of the banknote 30 along the predetermined scanning line 30b shown in FIG. The bill 30 is identified based on the acquired reflected light data and transmitted light data.

  Here, the reflected light data acquisition unit 40 and the transmitted light data acquisition unit 50 are configured to operate in a time-sharing manner. The reflected light data acquisition operation and the transmitted light data acquisition unit 50 are performed by the reflected light data acquisition unit 40. The transmitted light data acquisition operation by is configured not to interfere with each other.

  The identification of the banknote 30 based on the reflected light data and the transmitted light data in this embodiment is one of identifications based on various characteristics of the banknote 30. In practice, the reflected light data and transmitted light of the watermark area 30a are used. In addition to the identification based on the data, various known identifications are separately performed, and whether the banknote 30 is a genuine banknote or a counterfeit banknote is determined based on the comprehensive determination.

  The feature of the banknote identification device 100 of this embodiment is that the surface copy counterfeit banknote with the copy image pasted on the surface or the counterfeit banknote written on the watermark portion is easily based on the reflected light data of the watermark area 30a of the banknote 30. The point is that it can be identified.

  FIG. 2 is a waveform diagram showing an example of a reflected light waveform and a transmitted light waveform of the watermark region 30a when the banknote 30 is a genuine banknote in the configuration of FIG.

  That is, FIG. 2A shows a reflected light waveform of reflected light data acquired at a plurality of sample points in the watermark region 30a along the scanning line 30b in FIG. The vertical axis indicates the level of the reflected light data, and the horizontal axis indicates the address of each sample point.

  FIG. 2B shows a transmitted light waveform formed by reflected light data acquired at a plurality of sample points in the watermark region 30a along the scanning line 30b in FIG. Here, the vertical axis indicates the level of transmitted light data, and the horizontal axis indicates the address of each sample point.

  As is clear from FIGS. 2A and 2B, the reflected light waveform of the watermark region 30a shows only a small change in the watermark region 30a, but the transmitted light waveform is large corresponding to the watermark pattern in the watermark region 30a. It shows a change and the two are very different.

  3 shows the reflected light waveform (FIG. 3A) and transmitted light of the watermark area 30a when the banknote 30 is a counterfeit banknote having no watermark pattern in the watermark area 30a in the configuration of FIG. It is the wave form diagram which showed similarly an example of the waveform (FIG.3 (b)).

  As is clear from FIGS. 3A and 3B, in this case, since the watermark area 30a does not have a watermark pattern, both the reflected light waveform and the transmitted light waveform of the watermark area 30a show only a small change. The waveform is almost the same.

  Therefore, the reflected light data (reflected light waveform) of the watermark region 30a acquired by the reflected light data acquisition unit 40 is compared with the transmitted light data (transmitted light waveform) of the watermark region 30a acquired by the transmitted light data acquisition unit 50. It can be determined whether the banknote 30 is a genuine banknote or a counterfeit banknote having no watermark pattern in the watermark area 30a.

  FIG. 4 shows the watermark when the banknote 30 is a surface copy counterfeit banknote with a copy image pasted on the surface or a counterfeit banknote in which a pseudo watermark pattern is formed by writing on a watermark portion in the configuration of FIG. It is the wave form diagram which showed similarly an example of the reflected light waveform (FIG. 4 (a)) and transmitted light waveform (FIG.4 (b)) of the area | region 30a.

  As is clear from FIGS. 4A and 4B, in this case, the reflected light waveform and the transmitted light waveform of the watermark region 30a are substantially similar to each other. In this case as well, whether the banknote 30 is a genuine banknote. It is possible to identify whether or not.

  However, if the banknote is curved or flutters in the conveyance path, the reflected light reading pattern may be disturbed, and it may not be possible to accurately identify whether the banknote 30 is a genuine banknote.

  Now, in this invention, paying attention to the reflected light waveform of the surface copy counterfeit banknote with the copy image pasted on the surface or the counterfeit banknote formed by writing on the watermark portion and forming the pseudo watermark pattern, Based on the reflected light data, a surface copy counterfeit banknote with a copy image pasted on the surface or a counterfeit banknote on which a pseudo watermark pattern is formed by writing on a watermark portion is identified.

  FIG. 5 is a surface copy in which the reflected light waveform (FIG. 5A) of the watermark region 30a and the copy image of the banknote 30 are pasted on the surface when the banknote 30 is a genuine banknote in the configuration of FIG. It is the wave form diagram which showed similarly an example of the reflected light waveform (FIG.5 (b)) in the case of the forged banknote which wrote in the forged banknote or the watermark part, and formed the pseudo watermark pattern.

  Here, in FIGS. 5A and 5B, an average level straight line AVE corresponding to the average level of the reflected light waveform is obtained, and an area formed between the average level straight line AVE and the reflected light waveform (FIG. 5 ( When comparing a) and (b) indicated by hatching), there is a clear difference between the two.

  Therefore, by comparing the area with a predetermined threshold value, if the area is smaller than the predetermined threshold value, it is a genuine banknote, and if it is larger, it is written on a surface copy counterfeit banknote or a watermark portion with a copy image pasted on the surface. It is possible to determine that the forged banknote has a pseudo-watermark pattern.

  By the way, in the identification method using the above area, if the banknote 30 is curved or fluttered during conveyance and an abnormality occurs in the reflected light waveform, the above area becomes large even in genuine paper sheets. In some cases, it is not possible to accurately identify the surface copy counterfeit paper sheet or the written counterfeit paper sheet.

  FIG. 6A shows an example of the abnormal reflected light waveform of the reflected light data acquired by the reflected light data acquisition unit 40 from the watermark area 30a when the banknote 30 is curved or fluttered during conveyance. FIG.

  In this case, as described with reference to FIG. 5, when the average level straight line AVE corresponding to the average level of the reflected light waveform is obtained and the area formed between the average level straight line AVE and the reflected light waveform is obtained, Even if it is a genuine banknote, it becomes larger than the area shown by the oblique line in FIG. 5A as shown by the oblique line in FIG. 6B, and the surface copy counterfeit banknote or watermark part with the copy image pasted on the surface Will be erroneously detected as a counterfeit bill that has been written to.

  Therefore, in this embodiment, as shown in FIG. 6C, instead of the average level straight line AVE, a linear approximate line LF of the reflected light waveform is obtained, and the linear approximate line LF and the reflected light waveform are obtained. A surface copy counterfeit bill obtained by obtaining an area (indicated by hatching in FIG. 6 (c)) that is a genuine banknote if this area is smaller than a predetermined threshold value, and a copy image pasted on the surface if it is larger. Alternatively, it is determined that the forged banknote has been written in the watermark portion to form a pseudo watermark pattern.

  Here, the linear approximation line LF can be obtained by applying the least square method to the reflected light data acquired by the reflected light data acquisition unit 40 from the watermark region 30 a of the banknote 30.

According to such a configuration, even if the banknote 30 is curved or flutters during conveyance and the reflected light waveform becomes abnormal, the surface copy counterfeit banknote with the copy image pasted on the surface of the genuine banknote or There is no false detection of a counterfeit bill that has been written in the watermark. The method of calculating the linear approximation line LF by the least square method is that the reflected light data acquired by the reflected light data acquisition unit 40 from the watermark area 30a of the banknote 30 is (x1, y1), (x2, y2), ... (xn , Yn), y = ax + b, where

  It can be calculated from

  When the watermark area 30a of the banknote 30 has scratches, folds, etc., the scratches, creases, etc. are present in the reflected light waveform acquired by the reflected light data acquisition unit 40 and the transmitted light waveform acquired by the transmitted light data acquisition unit 50. Due to this, the banknote 30 cannot be accurately identified.

  Therefore, in the present invention, attention is paid to the phenomenon that the effect of the scratch, crease, etc. occurs at the same position of the reflected light waveform acquired by the reflected light data acquisition unit 40 and the transmitted light waveform acquired by the transmitted light data acquisition unit 50. Thus, after the reflected light waveform and the transmitted light waveform are corrected by removing the influence of the scratches, creases, and the like, the identification is performed.

  7 and 8 are diagrams for explaining the reflected light waveform and transmitted light waveform correction processing. FIG. 7A shows the reflected light waveform acquired by the reflected light data acquisition unit 40 when the watermark area 30a of the banknote 30 has scratches, folds, etc., and FIG. 7B shows the transmitted light data in that case. The transmitted light waveform acquired by the acquisition unit 50 is shown.

  As is clear from FIGS. 7A and 7B, the influence of the scratches, creases, and the like is caused by the reflected light waveform acquired by the reflected light data acquisition unit 40 and the transmitted light waveform acquired by the transmitted light data acquisition unit 50. At the same position.

  Therefore, as shown in FIG. 7, first, focusing on the waveform of the region Y where the scratches, folds and the like may occur, the peak positions of the reflected light waveform and the transmitted light waveform in this region are extracted.

  In the case of FIG. 7, peaks A, B, C, and D are extracted from the transmitted light waveform shown in FIG. 7B, and a peak E is extracted from the reflected light waveform shown in FIG. Here, the peak generated at the same position between the peak extracted from the transmitted light waveform shown in FIG. 7B and the peak extracted from the transmitted light waveform shown in FIG. Therefore, the transmitted light data in the vicinity of the peak C of the transmitted light waveform shown in FIG. 7B and the reflected light data in the vicinity of the peak E of the reflected light waveform shown in FIG. It can be determined that the data is affected by the above.

  Therefore, as shown in FIG. 8, the reflected light data and the peak C in the region Y in the vicinity of the peak E with respect to the reflected light waveform shown in FIG. 8A and the transmitted light waveform shown in FIG. Correction for removing transmitted light data in the region Y in the vicinity of is performed.

  As a result, it is possible to identify the banknote with high accuracy from which the influence of scratches, creases and the like generated in the watermark area 30a of the banknote 30 is removed.

  FIG. 9 is a block diagram illustrating a schematic configuration of the banknote recognition apparatus according to the first embodiment illustrated in FIG.

  In FIG. 9, the banknote identification apparatus includes a reflected light data acquisition unit 40 that acquires reflected light data of a banknote watermark area, a transmitted light data acquisition section 50 that acquires transmitted light data of a banknote watermark area, and the overall operation of the apparatus. And a banknote transport position detector 80 that detects the transport position of the banknote whose transport is controlled by the banknote transport controller 70. The

  Here, the reflected light data acquisition unit 40 corresponds to the reflected light data acquisition unit 40 shown in FIG. 1A, and illuminates the watermark region 30a of the banknote 30 shown in FIG. 40a and a reflected light data reading unit 40b that reads reflected light data from the watermark area 30a of the banknote 30, and the reflected light of the watermark area 30a of the banknote 30 along the predetermined scanning line 30b shown in FIG. Data is acquired, and the acquired reflected light data is passed to the control unit 60.

  The transmitted light data acquisition unit 50 corresponds to the transmitted light data acquisition unit 50 shown in FIG. 1A, and illuminates the watermark region 30a of the banknote 30 shown in FIG. 1B. And the reflected light data reading unit 50b that reads the transmitted light data from the watermark area 30a of the banknote 30, and the transmitted light data of the watermark area 30a of the banknote 30 along the predetermined scanning line 30b shown in FIG. And the acquired transmitted emission data is passed to the control unit 60.

   The reflected light data acquisition unit 40 and the transmitted light data acquisition unit 50 are configured using a light receiving element that is disposed on the scanning line 30b and outputs a read signal corresponding to the light receiving level along the scanning line 30b. However, instead of this light receiving element, a reflected light and transmitted light of the watermark region 30a are imaged using a two-dimensional imaging device such as a CCD camera, and then a received light level signal along the scanning line 30b is extracted. It may be configured.

  Moreover, the reflected light data acquisition unit 40 and the transmitted light data acquisition unit 50 are alternately activated in a time division manner in order to remove the influence of mutual interference.

  Further, the scanning line 30b can be set at an arbitrary position including the watermark area 30a of the banknote 30. However, in practice, it is preferable to set the scanning line 30b at a position including a lot of feature information effective for identifying the watermark area 30a.

  The banknote transport control unit 70 controls the transport rollers 10a and 10b shown in FIG. 1A by the control of the control unit 60, and the banknote 30 is transported by the transport belt 20 by the control of the banknote transport control unit 70. It is conveyed by.

  The banknote transport position detection unit 80 detects the transport position of the banknote 30 transported by the transport belt 20 by the banknote transport control unit 70.

  The addresses of the waveform diagrams shown in FIGS. 2 to 8 are given based on the conveyance position of the banknote 30 detected by the banknote conveyance position detection unit 80.

  The control unit 60 identifies the banknote based on the reflected light data acquired by the reflected light data acquisition unit 40 and the transmitted light data acquired by the transmitted light data acquisition unit 50.

  FIG. 10 is a flowchart showing a banknote recognition process performed by the control unit 60 of the banknote recognition apparatus shown in FIG.

  In the flowchart shown in FIG. 10, first, it is checked whether or not a bill has been inserted from a bill insertion slot (not shown) (step 101). If no banknote is inserted from the banknote insertion slot (NO in step 101), the process returns to step 101 and waits for the insertion of a banknote.

  If it is determined in step 101 that a banknote has been inserted (YES in step 101), the banknote 30 is started to be transported under the control of the banknote transport control unit 70, and the banknote 30 is based on the detection output of the banknote transport position detection unit 80. It is checked whether the watermark area 30a has reached the data acquisition positions of the reflected light data acquisition unit 40 and the transmitted light data acquisition unit 50 (step 102).

  Here, when it is determined that the watermark area 30a of the banknote 30 has reached the data acquisition positions of the reflected light data acquisition unit 40 and the transmitted light data acquisition unit 50 (YES in step 102), the reflected light data acquisition unit 40 The reflected light data of the watermark area 30a of the banknote 30 is acquired (step 103), and at the same time, the transmitted light data of the watermark area 30a of the banknote 30 is acquired by the transmitted light data acquisition unit 50 (step 104).

  Next, a data correction process between the reflected light data acquired by the reflected light data acquisition unit 40 and the transmitted light data acquired by the transmitted light data acquisition unit 50 is performed (step 105).

  As described with reference to FIGS. 7 and 8, the data correction process is performed by the reflected light data acquired by the reflected light data acquisition unit 40 and the transmission acquired by the transmitted light data acquisition unit 50 in order to improve the accuracy of identifying the banknote. This is a process for removing unnecessary waveforms based on scratches, creases and the like from optical data. A specific example of this data correction processing will be described later with reference to the flowchart of FIG.

  When the data correction processing of the reflected light data acquired by the reflected light data acquisition unit 40 and the transmitted light data acquired by the transmitted light data acquisition unit 50 is completed, first, using the corrected reflected light data and transmitted light data, banknotes The primary determination using the 30 watermark areas 30a is performed (step 106).

  This primary determination is a process of identifying counterfeit banknotes that do not have a watermark pattern in the watermark area 30a.

  That is, as described with reference to FIG. 2, the reflected light waveform and the transmitted light of the reflected light data acquired by the reflected light data acquisition unit 40 when the identification target banknote 30 is a genuine banknote having a regular watermark pattern in the watermark region 30 a. The transmitted light waveform of the transmitted light data acquired by the data acquisition unit 50 is greatly different.

  On the other hand, as described in FIG. 3, the reflected light waveform of the reflected light data acquired by the reflected light data acquisition unit 40 when the identification target banknote 30 is a forged banknote having no watermark pattern in the watermark region 30 a. And the transmitted light waveform acquired by the transmitted light data acquisition unit 50 substantially match.

  Therefore, in this watermark area primary determination process, the reflected light waveform and the transmitted light waveform are compared, and if they match, the identification target banknote 30 is a counterfeit banknote having no watermark pattern in the watermark area 30a. Identify. A specific example of the watermark area primary determination process will be described later with reference to the flowchart of FIG.

  When the watermark area primary determination process ends, the watermark area secondary determination process is performed next. This watermark area secondary determination process is a process of identifying a surface copy counterfeit banknote with a copy image pasted on the surface or a counterfeit banknote in which a pseudo watermark pattern is formed by writing on the watermark section. This is performed based on the reflected light data acquired by the above.

  That is, as described with reference to FIG. 5, the reflected light of the watermark area 30 a of the counterfeit banknote in which the identification target banknote 30 has the copy image pasted on the surface or the counterfeit banknote is formed by writing on the watermark portion. The waveform is slightly different from the reflected light waveform of the watermark area 30a of the genuine bill.

  Therefore, in the watermark area secondary determination process, paying attention to this point, based on the reflected light waveform of the identification target banknote 30, the surface copy counterfeit banknote or the watermark section in which the identification target banknote 30 has a copy image pasted on the surface thereof. The counterfeit banknote is identified by forming a pseudo watermark pattern. A specific example of the watermark area secondary determination process will be described later with reference to the flowchart of FIG.

  Next, the watermark region primary determination process performed in step 106, the watermark region secondary determination process performed in step 107, and the well-known identification results omitted in other explanations are combined to output the determination result of the bill 30 (step 108), the process ends.

  FIG. 11 is a flowchart showing a specific example of the data correction processing in step 105 shown in FIG.

  In the data correction process of FIG. 11, it has shown about the process which removes the unnecessary waveform based on the fold of a banknote.

  The position (address) of the fold perpendicular to the scanning line 30b of the bill 30 can be predicted in advance if the bill 30 can be identified. Therefore, in the data correction process shown in FIG. 11, the address of the area where it is predicted that a crease can be made is set in advance as a crease determination area, and the data correction process is performed based on the reflected light data in this fold determination area. This fold determination area is indicated by an area X in FIG.

  When this process is started, first, the reflected light data and transmitted light data of the crease determination area are extracted (step 201). Then, the peak positions of the reflected light data and the transmitted light data are extracted. In FIG. 7, a peak E is extracted from the reflected light waveform shown in FIG. 7A, and peaks A, B, C, and D are extracted from the transmitted light waveform shown in FIG. 7B.

  Next, it is examined whether or not there is a matching portion between the peak position of the extracted reflected light waveform and the peak position of the transmitted light (step 203).

  If there is no matching part (NO in step 203), this data correction process is deemed unnecessary and this process ends.

  If it is determined in step 203 that there is a matching part (YES in step 203), the reflected light data and transmitted light data of the area of this part are extracted (step 204). Here, the extracted areas of reflected light data and transmitted light data are areas in the vicinity including the matched peak positions, and are indicated by area Y in FIG.

  Next, data correction for removing the extracted reflected light data and transmitted light data is performed (step 205), and this process is terminated.

  FIG. 12 is a flowchart showing a specific example of the watermark area primary determination processing in step 106 shown in FIG.

  In this watermark area primary determination process, it is identified whether the identification target banknote 30 is a counterfeit banknote having no watermark pattern in the watermark area 30a.

  That is, in the watermark region primary determination process shown in FIG. 12, first, the reflected light waveform of the reflected light data acquired by the reflected light data acquisition unit 40 and the transmitted light waveform of the transmitted light data acquired by the transmitted light data acquisition unit 50 Are compared (step 301).

  Based on this comparison, if the reflected light waveform and the transmitted light waveform match (YES in step 302), the identification target banknote 30 is identified as a counterfeit banknote that does not have a watermark pattern in the watermark area 30a. (Step 303), this process is terminated.

  If the reflected light waveform does not match the transmitted light waveform in the comparison in step 302 (NO in step 302), the process is terminated as it is.

  FIG. 13 is a flowchart showing a specific example of the watermark area secondary determination process in step 106 shown in FIG.

  In this watermark area secondary determination process, based on the reflected light waveform of the identification target banknote 30, the identification target banknote 30 writes a surface copy counterfeit banknote with a copy image pasted on the surface or a watermark portion to create a pseudo watermark pattern. It is identified whether it is a counterfeit bill that has formed.

  Specifically, as described with reference to FIG. 6, a linear approximation line is obtained by applying the least square method to the reflected light data of the identification target banknote 30, and the reflected light formed by the linear approximate line and the reflected light data The area between the curved line is obtained, and based on this area, it is discriminated whether it is a surface copy counterfeit banknote with a copy image pasted on the surface or a counterfeit banknote in which a watermark is written to form a pseudo watermark pattern.

  That is, in the watermark area secondary determination process shown in FIG. 13, first, a linear approximation line is calculated by applying the least square method to the reflected light data acquired by the reflected light data acquisition unit 40 (step 401). .

  Next, the area between the linear approximation line calculated in step 401 (linear approximation line LF in FIG. 6) and the reflected light curve formed by the reflected light data acquired by the reflected light data acquisition unit 40 is calculated (step 402). .

  Then, it is checked whether or not the area calculated in step 402 is larger than a preset threshold value (step 403). If it is larger (YES in step 403), the surface copy counterfeit banknote on which the copy image is pasted on the surface is identified. Alternatively, it is identified as a counterfeit bill that has been written in the watermark portion to form a pseudo watermark pattern (step 404).

  If it is determined in step 403 that the area calculated in step 402 is smaller than a preset threshold value (NO in step 403), this process is terminated.

  According to such a configuration, even if the banknote 30 is curved or flutters during conveyance, and the reflected light waveform becomes abnormal, the surface copy counterfeit banknote or watermark part with the copy image pasted on the surface Forged banknotes that have been written to form a pseudo-watermark pattern can be reliably identified.

  FIG. 14: is a figure which shows schematic structure of the banknote identification device of Example 2 comprised by applying this invention.

  In the second embodiment, a reflected light data acquisition unit 90 that acquires reflected light data on the back surface of the banknote 30 is added to the banknote identification device of the first embodiment shown in FIG.

  Here, the reflected light data acquisition unit 90 includes a light emitting unit 90a that illuminates the back surface of the watermark area 30a of the banknote 30 and a reflected light data reading unit 90b that reads the reflected light from the back surface of the watermark area 30a. Other configurations are the same as those of the banknote recognition apparatus of the first embodiment shown in FIG. In FIG. 14, the part which fulfill | performs the function similar to the banknote identification apparatus of Example 1 shown to Fig.1 (a) attaches | subjects the code | symbol same as the code | symbol used in Fig.1 (a), and the detailed description is given. Omitted.

  In Example 2 shown in FIG. 14, the reflected light data acquisition unit 40 including the light emitting unit 40a and the reflected light data reading unit 40b for acquiring the reflected light data from the surface of the watermark region 30a of the bill 30, and the transmission of the watermark region 30a. In addition to the transmitted light data acquiring unit 50 including the light emitting unit 50a and the transmitted light data reading unit 50b for acquiring optical data, the light emitting unit 90a and the reflected light data for acquiring reflected light data from the back surface of the watermark area 30a of the banknote 30. Since the reflected light data acquisition unit 90 including the reading unit 90b is provided, the first reflected light data acquired by the reflected light data acquisition unit 40, the transmitted light data acquired by the transmitted light data acquisition unit 50, and the reflected light data. The bill is identified based on the second reflected light datum acquired by the acquisition unit 90.

  According to such a configuration, in the watermark region primary determination in step 106 of FIG. 10 of the first embodiment, the watermark pattern is added to the watermark region 30a in consideration of the matching of the reflected light waveform acquired by the reflected light data acquisition unit 90. It can comprise so that the forged banknote which does not have may be identified.

  That is, according to the configuration of the first embodiment, only the reflected light data on one side of the banknote 30 is acquired. For example, it is not possible to identify a counterfeit banknote in which a copy is pasted on both the front and back sides. According to the configuration, since the reflected light data on both sides of the banknote 30 is acquired, it becomes possible to identify a counterfeit banknote in which a copy is pasted on both sides.

  Further, in the watermark area secondary determination process of step 106 shown in FIG. 10, instead of or in addition to the first reflected light data acquired by the reflected light data acquisition unit 40, the first acquired by the reflected light data acquisition unit 90. The same processing is also performed on the reflected light data of 2 to identify whether the copy is a forged banknote with a copy image pasted on the surface or a forged banknote having a pseudo watermark pattern written on the watermark portion. It can be carried out.

  Further, in this configuration, in the data correction process in step 105 shown in FIG. 10, the same peak position is detected for the first reflected light data, transmitted light data, and second reflected light data. Thus, a similar data correction process for removing the influence of scratches, creases and the like is performed.

  In this case, it is possible to perform data correction processing that removes the influence of scratches, folds, etc. using the first reflected light data, transmitted light data, and second reflected light data, so the influence of scratches, creases, etc. is removed. The accuracy of the data correction process to be performed is improved.

  It is also possible to perform data correction processing that removes the influence of scratches, folds, etc., using the two pieces of data of the first reflected light data and the second reflected light data.

  In addition, in the said Example, although shown when this invention was applied to the identification of the banknote which has a watermark area | region, if it has a watermark area | region, not only a banknote but paper sheets, such as various securities, will be shown. The same applies to identification.

  The present invention is applicable to identification of paper sheets having a watermark area. According to this invention, the reflected light data of the watermark area is acquired from the reflected light of the watermark area of the paper sheet, the linear approximate line is calculated from the acquired reflected light data, and the calculated linear approximate line and the reflected light are calculated. Since the area formed between the reflected light curve formed by the optical data is calculated and the paper sheet is determined based on the calculated area, the identification target paper sheet is bent or fluttered during conveyance. For example, it is possible to reliably identify a surface copy forged paper sheet on which a copy image is pasted or a forged paper sheet on which a watermark has been written.

It is a figure which shows schematic structure of the banknote identification device of Example 1 comprised by applying this invention. It is the wave form diagram which showed an example of the reflected light waveform of the watermark area | region of a genuine banknote, and the transmitted light waveform. It is the wave form diagram which showed an example of the reflected light waveform and transmitted light waveform of the forged banknote which does not have a watermark pattern. It is the wave form diagram which showed an example of the reflected light waveform and transmitted light waveform of the surface copy forgery banknote which affixed the copy image on the surface, or the forgery banknote which wrote in the watermark part and formed the pseudo watermark pattern. An example of the reflected light waveform of the watermark area in the case of a genuine banknote and the reflected light waveform of a surface copy counterfeit banknote with a copy image pasted on the surface or a counterfeit banknote formed by writing on the watermark portion to form a pseudo watermark pattern It is a waveform diagram. It is a figure explaining the detection method of the forged banknote which wrote in the surface copy forged banknote which pasted the copy image on the surface in this invention, or the watermark part. It is a figure explaining the correction process of a reflected light waveform and a transmitted light waveform. It is a figure explaining the correction process of a reflected light waveform and a transmitted light waveform. It is a block diagram which shows schematic structure of the banknote identification device of Example 1 shown to Fig.1 (a). It is a flowchart which shows the banknote identification process performed by the control part of the banknote identification apparatus shown in FIG. It is a flowchart which shows the specific example of the data correction process shown in FIG. 11 is a flowchart showing a specific example of the watermark area primary determination process shown in FIG. 10. 11 is a flowchart illustrating a specific example of the watermark area secondary determination process illustrated in FIG. 10. It is a figure which shows schematic structure of the banknote identification device of Example 2 comprised by applying this invention.

Explanation of symbols

10a, 10b Conveying roller 20 Conveying belt 30 Bill 30a Watermark area 30b Scanning line 40 Reflected light data acquisition unit 40a Light emitting unit 40b Reflected light data reading unit 50 Transmitted light data acquiring unit 50a Light emitting unit 50b Transmitted light data reading unit 60 Control unit 70 Banknote transport control unit 80 Banknote transport position detection unit 90 Reflected light data acquisition unit 90a Light emitting unit 90b Reflected light data reading unit

Claims (9)

In a paper sheet identification apparatus for identifying a paper sheet having a watermark area in which a watermark pattern is formed,
Reflected light data acquisition means for acquiring reflected light data of the watermark region from reflected light of the watermark region of the paper sheet;
Calculating means for calculating a linear approximation line from the reflected light data acquired by the reflected light data acquiring means;
Area calculating means for calculating an area formed between the linear approximation line calculated by the calculating means and the reflected light curve formed by the reflected light data;
And a discriminating unit that discriminates the paper based on the area calculated by the area calculating unit. The calculating means includes
The paper sheet identification apparatus according to claim 1, wherein the linear approximation line is calculated by applying a least square method to the reflected light data. The discrimination means includes
3. The paper sheet identification apparatus according to claim 1, wherein when the total area calculated by the area calculation unit is smaller than a predetermined threshold value, the paper sheet is determined to be a genuine paper sheet. In a paper sheet identification apparatus for identifying a paper sheet having a watermark area in which a watermark pattern is formed,
Transmitted light data acquisition means for acquiring transmitted light data of the watermark area from the transmitted light of the watermark area of the paper sheet;
Reflected light data acquisition means for acquiring reflected light data of the watermark region from reflected light of the watermark region of the paper sheet;
Extracting means for extracting data of a portion where the peak positions of the transmitted light data acquired by the transmitted light data acquiring means and the reflected light data acquired by the reflected light data acquiring means match;
Data correction means for removing data from the transmitted light data and reflected light data, assuming that the data extracted by the extraction means is data on the scratches or creases in the paper sheet,
An identification unit for identifying the sheet based on the transmitted light data and the reflected light data corrected by the data correction unit. The identification means includes
A calculating means for calculating a linear approximation line from the reflected light data corrected by the data correcting means;
Area calculating means for calculating an area formed between the linear approximation line calculated by the calculating means and the reflected light curve formed by the reflected light data corrected by the data correcting means;
The paper sheet identification apparatus according to claim 4, further comprising: a determination unit configured to determine the paper sheet based on the area calculated by the area calculation unit. In a paper sheet identification apparatus for identifying a paper sheet having a watermark area in which a watermark pattern is formed,
Transmitted light data acquisition means for acquiring transmitted light data of the watermark area from the transmitted light of the watermark area of the paper sheet;
First reflected light data acquisition means for acquiring first reflected light data of the watermark region from the reflected light of the surface of the watermark region of the paper sheet;
Second reflected light data acquisition means for acquiring second reflected light data of the watermark area from the reflected light of the back surface of the watermark area of the paper sheet;
The transmitted light data acquired by the transmitted light data acquisition means, the first reflected light data acquired by the first reflected light data acquisition means, and the second reflected light data acquired by the second reflected light data acquisition means Extracting means for extracting the data of the portion where the peak positions coincide with each other;
Data correcting means for removing data from the transmitted light data, the first reflected light data, and the second reflected light data, assuming that the data extracted by the extracting means is data on a scratch or crease in the paper sheet. When,
An identifying means for identifying the paper based on the transmitted light data, the first reflected light data, and the second reflected light data corrected by the data correcting means; . In a paper sheet identification method for identifying a paper sheet having a watermark area in which a watermark pattern is formed,
Obtaining reflected light data of the watermark area from reflected light of the watermark area of the paper sheet by reflected light data acquisition means,
A linear approximation line is calculated by the calculating means from the reflected light data acquired by the reflected light data acquiring means,
An area calculated between the linear approximation line calculated by the calculating means and the reflected light curve formed by the reflected light data is calculated by the area calculating means;
A paper sheet identification method comprising: discriminating the paper sheet based on the area calculated by the area calculating means. In a paper sheet identification method for identifying a paper sheet having a watermark area in which a watermark pattern is formed,
Obtaining transmitted light data of the watermark area from the transmitted light of the watermark area of the paper sheet by transmitted light data acquisition means,
Obtaining reflected light data of the watermark area from reflected light of the watermark area of the paper sheet by reflected light data acquisition means,
Extracting the data of the portion where the peak position coincides with the transmitted light data acquired by the transmitted light data acquisition means and the reflected light data acquired by the reflected light data acquisition means, by the extraction means,
The data extracted by the extracting means is data correction means for removing data from the transmitted light data and reflected light data, assuming that the data of the paper sheet is a scratch or a crease,
The paper sheet identification method, wherein the paper sheet is identified by the identification means based on the transmitted light data and the reflected light data corrected by the data correction means. In a paper sheet identification method for identifying a paper sheet having a watermark area in which a watermark pattern is formed,
Obtaining transmitted light data of the watermark area from the transmitted light of the watermark area of the paper sheet by transmitted light data acquisition means,
First reflected light data of the watermark region is acquired by first reflected light data acquisition means from the reflected light of the surface of the watermark region of the paper sheet,
Second reflected light data of the watermark region is acquired from the reflected light of the back surface of the watermark region of the paper sheet by a second reflected light data acquisition unit;
The transmitted light data acquired by the transmitted light data acquisition means, the first reflected light data acquired by the first reflected light data acquisition means, and the second reflected light data acquired by the second reflected light data acquisition means Extract the data of the part where the peak position matches with the extraction means,
The data extracted by the extracting means is data of scratches or creases on the paper sheet, and data correction is performed to remove from the transmitted light data, the first reflected light data, and the second reflected light data, respectively. By data correction means,
The paper sheet identifying method, wherein the paper sheet is identified by the identifying means based on the transmitted light data, the first reflected light data, and the second reflected light data corrected by the data correcting means.

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