JP2018169881A - Serial number reading device, paper sheet identification device, paper sheet processing device, and serial number reading method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a serial number reading device, a paper sheet identification device, a paper sheet processing device, and a serial number reading method that can improve the accuracy of reading serial numbers emitting fluorescent light.SOLUTION: Provided is a serial number reading device that reads serial numbers written on paper sheets and absorbing visible light and emitting fluorescent light. The serial number reading device includes: an optical line sensor that sequentially irradiates a serial number region of a paper sheet to be transported with visible light and excitation light to acquire visible light image data and fluorescent light image data of the serial number region; and a position determination unit that determines whether or not a serial number detected from the fluorescent light image data is present at a position corresponding to the serial number detected from the visible light image data.SELECTED DRAWING: Figure 8

Description

The present invention relates to a serial number reading device, a paper sheet identification device, a paper sheet processing device, and a serial number reading method. More specifically, the present invention relates to a serial number reading device, a paper sheet identification device, a paper sheet processing device, and a serial number reading method suitable for reading serial numbers written on paper sheets.

Currently, in a paper sheet identification apparatus, the type of paper sheet, damage determination, authenticity determination, and the like are performed in the process of transporting paper sheets. Among these, the authenticity determination of the paper sheet is performed, for example, by analyzing the image of the paper sheet read by the optical line sensor. In this case, for example, the authenticity of the paper sheet is determined based on the sequence of the serial numbers of the paper sheet and the number of digits.

For example, in Patent Document 1, a series of numbers is printed with fluorescent ink, and the number made of the fluorescent ink is the number made of short-wavelength fluorescent ink and the number made of long-wavelength fluorescent ink. A number printing medium on which a forgery prevention measure capable of authenticating with a lamp is applied is disclosed.

In Patent Document 2, regarding optical line sensors, visible light, ultraviolet light, and infrared light are irradiated on a medium, and light reflected or transmitted from the medium is transmitted with respect to light in the visible wavelength band. A technology for independently acquiring visible wavelength and color information of light sources other than visible wavelengths with a small number of light source lighting times by receiving light with a light receiving element having different color filters (R), (G), and (B). It is disclosed.

Further, in Patent Document 3, with respect to the optical line sensor, light of a plurality of different wavelength bands including at least the wavelength band of the visible light region and the infrared light region is irradiated on the banknote with overlapping timing, and the wavelength of each light source By simultaneously obtaining the received light intensity of the light of the wavelength in the range corresponding to the wavelength band of each light source from the banknote by the light receiving element including the band pass filter that transmits only the light of the wavelength in the range corresponding to the band, A technique for efficiently preventing a decrease in resolution and accuracy of each image is disclosed.

JP 2006-205500 A Japanese Patent Laid-Open No. 2006-9445 JP, 2006-53783, A

In recent years, in order to tighten the management of paper sheets such as banknotes, gift certificates, and checks, the market demands to improve the recognition function of serial numbers written on paper sheets both at home and abroad. ing. Currently, there are banknotes and checks that employ a fluorescent serial number as a security element.

However, in the conventional optical line sensor, it is difficult to read such a serial number that emits fluorescence, that is, to recognize characters. FIG. 18 is a schematic diagram for explaining an image data acquisition mode in the image data acquisition step of the serial number reading method according to comparative embodiment 1. FIG. 19 is a schematic diagram for explaining the concept of the serial number reading method according to Comparative Example 1, and shows banknote information, a visible light image, and a fluorescence image of a banknote on which the serial number is written. As shown in FIG. 18, in the first comparative example, the resolution in the sub-scanning direction of the visible light image is high, and data of one line or more is collected with respect to the line width of the character with the serial number. The serial number detected from the visible light image can be read in character units (character recognition). However, as shown in FIG. 18, the fluorescence image has a low resolution in the sub-scanning direction, and the serial number of the fluorescent light is blurred in its outline. Therefore, as shown in FIG. It is difficult to detect.

Further, in the serial number reading device according to the comparative example 1, even if only the resolution of the fluorescent image is increased, detection of the serial number in units of characters is possible, but the fluorescence emission (fluorescence reaction) itself is uneven. Therefore, it is still difficult to recognize the serial number from the fluorescent image alone. In particular, when the paper sheet is twisted or the fluorescent material is deteriorated, or when the serial number is composed of small symbols, it is difficult to recognize the serial number from the fluorescent image, and the serial number recognition rate ( The probability of correctly recognizing characters is reduced.

Furthermore, in Comparative Example 1, since the light source that irradiates the excitation light is long after the light source is turned off and is turned on again, the signal component due to the phosphorescence of the serial number is not included in the output signal of the optical line sensor. This is a disadvantage in extracting the serial number.

Further, Patent Documents 1 to 3 do not describe the technical problem related to reading of serial numbers that emit fluorescence, and have not solved the technical problem.

The present invention has been made in view of the above-described situation, and provides a serial number reading device, a paper sheet identification device, a paper sheet processing device, and a serial number reading method capable of improving the reading accuracy of serial numbers emitted with fluorescence. It is intended to provide.

The present invention is a serial number reading device that reads serial numbers that are written on paper sheets and that absorbs and emits visible light, and sequentially applies visible light and excitation light to the serial number areas of the transported paper sheets. An optical line sensor that irradiates and obtains visible light image data and fluorescent image data of the serial number region, and a serial number detected from the fluorescent image data corresponds to a serial number detected from the visible light image data And a position determination unit that determines whether or not it exists at a position to be detected.

Further, the present invention is the above invention, wherein the position determination unit calculates a degree of coincidence by superimposing a fluorescent image based on the fluorescent image data and a visible light image based on the visible light image data, and the calculated degree of coincidence Based on the above, the determination is performed.

In the invention described above, the serial number reading device may be configured such that the serial number obtained by performing character recognition on the fluorescent image based on the fluorescent image data and the character on the visible light image based on the visible light image data. It is further characterized by further comprising a character determination unit for determining whether or not the serial number obtained by the recognition matches.

Further, the present invention is the above invention, wherein in the optical line sensor, the resolution in the sub-scanning direction when the visible light and the excitation light are irradiated is less than the line width of the serial number described on the paper sheet. It is characterized by being.

In the invention described above, the optical line sensor irradiates the visible light and the excitation light continuously.

Further, the present invention is the above invention, wherein the optical line sensor includes a plurality of filters that transmit light in different wavelength bands and a plurality of light receiving elements that receive light transmitted through the plurality of filters. Features.

In the invention described above, the serial number reader further includes a color detection unit that detects a color of the serial number detected from the fluorescent image data.

In the invention described above, the excitation light is ultraviolet light.

Further, the present invention is the above invention, wherein the visible light image data is reflected light image data of the paper sheet, and the fluorescent image data is irradiated with the excitation light on the basis of the paper sheet. It is acquired by the light-receiving part located in the same side as a light source, It is characterized by the above-mentioned.

In the invention described above, the optical line sensor further irradiates paper sheets with infrared light.

Further, the present invention is a paper sheet identification device comprising: the serial number reading device; and a true / false determination unit that determines the authenticity of the paper sheet based on at least a determination result of the position determination unit. It is characterized by providing.

Moreover, the present invention is a paper sheet processing apparatus, comprising the paper sheet identification apparatus.

The present invention is also a serial number reading method for reading serial numbers that are written on paper sheets and that absorbs visible light and emits fluorescent light, and is recorded in the serial number area of the paper sheets being conveyed by an optical line sensor. An image acquisition step of acquiring visible light image data and fluorescent image data of the serial number region by sequentially irradiating visible light and excitation light, and a serial number detected from the fluorescent image data are obtained from the visible light image data. And a position determination step for determining whether or not it exists at a position corresponding to the detected serial number.

According to the serial number reading device, the paper sheet identification device, the paper sheet processing device, and the serial number reading method of the present invention, it is possible to improve the reading accuracy of serial numbers emitted with fluorescence.

It is a plane schematic diagram which shows an example of the banknote in which the serial number was described. It is a plane schematic diagram which shows the example of the serial number described in the banknote, (a) shows the visible character visible under visible light, (b)-(e) is visible under excitation light. Fluorescent letters are shown. It is a schematic diagram for demonstrating the concept of the serial number reading method which concerns on Embodiment 1, and shows the banknote information, visible light image, and fluorescence image of the banknote in which the serial number was described. FIG. 6 is a schematic diagram for explaining an example of processing in a position determination step of the serial number reading method according to Embodiment 1, wherein (a) represents a partial image including a serial number from a binarized image of a visible light image as a symbol unit; (B) shows a case where a partial image including a serial number is extracted from a fluorescent image in symbol units. It is a schematic diagram for demonstrating another example of the process in the position determination step of the serial number reading method which concerns on Embodiment 1, (a) is a partial image containing a serial number from the binarized image of a visible light image. The case where it extracted is shown, (b) shows the case where the partial image containing a serial number is extracted from the fluorescence image. It is a schematic diagram for demonstrating the acquisition aspect of the image data in the image data acquisition step of the serial number reading method which concerns on Embodiment 1. FIG. It is a schematic diagram for demonstrating the concept of the image formation method of the banknote by the serial number reader which concerns on Embodiment 1. FIG. It is a block diagram which shows the internal structure of the serial number reading apparatus which concerns on Embodiment 1, and a banknote identification device. It is sectional drawing which cut | disconnected the optical line sensor which concerns on Embodiment 1 on the surface perpendicular | vertical to the conveyance surface of a banknote, and parallel to the conveyance direction of a banknote. FIG. 5 is a cross-sectional view showing the correspondence between the arrangement of light receiving elements in the light receiving unit of the optical line sensor according to Embodiment 1 and the filter. It is sectional drawing which shows the detailed structure of the light emission part shown in FIG. 9, and a condensing lens. It is sectional drawing which shows arrangement | positioning of the LED element in the LED header shown in FIG. 10 is a timing chart showing the light emission timing of the light emitting unit and the light reception timing of the light receiving unit of the optical line sensor shown in FIG. 9. FIG. 10 is a control block diagram showing a flow of processing for forming image data based on data acquired by the optical line sensor shown in FIG. 9. It is a flowchart which shows the processing flow of the serial number reader which concerns on Embodiment 1, and a banknote identification device. (A) is the perspective schematic diagram which showed the external appearance of the banknote processing apparatus which concerns on Embodiment 1, (b) is the cross-sectional schematic diagram which showed the structure outline | summary inside the banknote processing apparatus which concerns on Embodiment 1. FIG. It is the isometric view schematic diagram which showed the external appearance of another banknote processing apparatus which concerns on Embodiment 1. FIG. It is a schematic diagram for demonstrating the acquisition aspect of the image data in the image data acquisition step of the serial number reading method which concerns on the comparison form 1. FIG. It is a schematic diagram for demonstrating the concept of the serial number reading method which concerns on the comparison form 1, and shows the banknote information, visible light image, and fluorescence image of the banknote in which the serial number was described.

Preferred embodiments of a serial number reading device, a paper sheet identification device, a paper sheet processing device, and a serial number reading method according to the present invention will be described below with reference to the drawings. As the paper sheets subject to the present invention, various paper sheets such as banknotes, checks, gift certificates, bills, forms, securities, and card-like media can be applied. The present invention will be described by taking the apparatus and method as an example. In addition, the following description is an example of a serial number reading apparatus, a banknote identification apparatus, a banknote processing apparatus, and a serial number reading method.

(Banknotes to be processed)
First, a bill to be processed according to this embodiment will be described. FIG. 1 is a schematic plan view showing an example of banknotes with serial numbers. As shown in FIG. 1, the bill to be processed absorbs light in at least a part of the wavelength range in the visible range (for example, 380 to 780 nm) and emits fluorescence by the irradiated excitation light. Those with 1 are preferred.

In this specification, “fluorescence” refers to fluorescence that has a short life (nearly no lifetime) after the excitation light (light for excitation) is stopped and has long life and afterglow. Any phosphorescence to be included.

The serial number 1 is printed on a banknote by printing colored ink and fluorescent ink on a base material (for example, paper) of the banknote. Examples of the colored ink include those containing general pigments and dyes, and examples of the fluorescent ink include those containing a general fluorescent material. 2A to 2E are schematic plan views illustrating an example of serial number 1 described on a banknote. The serial number 1 is a serial number for distinguishing banknotes one by one, and is composed of symbols such as letters and numbers, and has information on the symbols themselves and color information on the symbols. The banknotes are distinguished by these pieces of information. Moreover, the serial number 1 is composed of the visible serial number 1a that is visible under visible light, as shown in FIG. 2 (a) when irradiated with visible light, and in FIG. 2 (b) when irradiated with excitation light. As shown, it consists of a fluorescent serial number 1b visible under excitation light. 2B to 2E, the hatched portion indicates the fluorescent serial number 1b, and the broken line indicates the outline of the visible serial number 1a. The visible serial number 1a is visible when the colored ink absorbs at least a part of the visible wavelength band, while the fluorescent serial number 1b is visible when the fluorescent ink is excited by excitation light. It is visible by emitting fluorescence in at least a part of the wavelength band. The type (wavelength range) of the excitation light is not particularly limited and can be appropriately selected according to the characteristics of the fluorescent material, but ultraviolet light is preferred.

The fluorescent serial number 1b is arranged at a position corresponding to the visible serial number 1a. Specifically, for example, as shown in FIG. 2 (b), the fluorescent serial number 1b completely coincides with the visible serial number 1a, and the fluorescent serial number 1b and the visible serial number 1a indicate their shape and position. In addition, the line widths may coincide with each other. In this case, the fluorescent serial number 1b exists on the boundary and inside the visible serial number 1a. Further, as shown in FIGS. 2 (c) and (d), the fluorescent serial number 1b is thicker or thinner than the visible serial number 1a, and the fluorescent serial number 1b and the visible serial number 1a have their shapes. While the positions coincide with each other, the line widths may be different from each other. Further, as shown in FIG. 2 (e), the fluorescent serial number 1b may partially coincide with the visible serial number 1a, and a part of the visible serial number 1a may be missing.

The serial number reading device, the paper sheet identification device, the paper sheet processing device, and the serial number reading method according to the present embodiment shown below are for various banknotes on which serial numbers that absorb visible light and emit fluorescence are written. However, the serial number can be read with high accuracy.

(Concept of serial number reading method)
Next, the concept of the serial number reading method according to the present embodiment will be described. FIG. 3 is a schematic diagram for explaining the concept of the serial number reading method according to the first embodiment, and shows banknote information, a visible light image, and a fluorescence image of the banknote on which the serial number is written. In this embodiment, first, as shown in FIG. 3, visible light and excitation are generated in at least the serial number region 2 of the banknote on which the serial number to be conveyed is written by an optical line sensor (hereinafter also simply referred to as a line sensor). By sequentially irradiating light, at least visible light image data and fluorescence image data in the serial number region 2 are acquired (image data acquisition step). However, since the line sensor is usually provided so as to cross the entire conveyance path in which the banknote is conveyed, the line sensor acquires image data including the entire banknote and its background.

Next, the serial number (hereinafter also referred to as fluorescent image serial number) 3 detected from the fluorescent image data is changed to the serial number (hereinafter also referred to as visible light image serial number) 4 detected from the visible light image data. It is determined whether or not it exists at a corresponding position (position determination step). Hereinafter, the position determination step will be described in detail with reference to FIG. FIG. 4 is a schematic diagram for explaining an example of processing in the position determination step of the serial number reading method according to the first embodiment. FIG. 4A is a part including serial numbers from a binarized image of a visible light image. A case where an image is extracted in symbol units is shown, and (b) shows a case where a partial image including a serial number is extracted from a fluorescent image in symbol units.

In the position determination step, first, the visible light image data is binarized based on a predetermined threshold value to generate binarized image data. Next, as shown in FIG. 4A, based on the denomination and direction of the banknote determined by the identification process, the serial number region is generated in a predetermined shape (for example, rectangular shape) in symbol units from the generated binary image data. To generate a partial image 5a. And the symbol part in each partial image 5a is detected as visible light image serial number 4. That is, typeface information such as the shape, position, and line width of the visible light image serial number 4 in each partial image 5a is determined. In this specification, the partial image means an image constituting a part of the entire image.

Next, as shown in FIG. 4 (b), the serial number area is cut out from the fluorescent image data into a predetermined shape (for example, a rectangular shape) from the fluorescent image data based on the denomination and direction of the banknote determined by the identification process. An image 5b is generated, and the presence or absence of fluorescence emission in each partial image 5b is determined. The presence / absence of fluorescence emission is determined, for example, by comparing the pixel value with a predetermined threshold value. Then, it is determined whether or not the position of the pixel determined to have fluorescence emission in each partial image 5b corresponds to the position of the visible light image serial number 4 of the corresponding partial image 5a.

Specifically, for example, as shown in FIG. 2 (b), when the fluorescent serial number 1b completely coincides with the visible serial number 1a, each pixel determined to have fluorescent emission in the partial image 5b is displayed. What is necessary is just to determine whether it is located in the same place as one of the pixels which comprise the visible light image serial number 4 in the corresponding partial image 5a. Further, in this case, the pixel having the visible light image serial number 4 in the corresponding partial image 5a is the position of the pixel determined to have fluorescent emission and the pixel determined to have no fluorescent emission in the partial image 5b. It may be determined whether or not it matches the position of a missing pixel.

Further, as shown in FIG. 2 (e), even in the case where the fluorescent serial number 1b is a part in which the visible serial number 1a is missing, the pixel determined to have fluorescent emission in the partial image 5b is What is necessary is just to determine whether it is located in the same place as one of the pixels which comprise the visible light image serial number 4 in the corresponding partial image 5a.

As shown in FIGS. 2C and 2D, when the fluorescent serial number 1b is thicker or thinner than the visible serial number 1a, the binarized image data of the visible light image data is expanded. Alternatively, the same determination process may be performed using the thinned image data.

In the position determination step of the present embodiment, the degree of coincidence is calculated by superimposing the fluorescent image based on the fluorescent image data and the visible light image based on the visible light image data, and the fluorescent image serial number 3 is calculated based on the calculated degree of coincidence. May be present at a position corresponding to the visible light image serial number 4. FIG. 5 is a schematic diagram for explaining another example of processing in the position determination step of the serial number reading method according to the first embodiment. FIG. 5A illustrates serial numbers from a binarized image of a visible light image. A case where a partial image including the serial number is extracted is shown, and (b) shows a case where a partial image including a serial number is extracted from the fluorescent image.

In this case, first, as shown in FIG. 5A, the serial number area is cut out in a predetermined shape (for example, a rectangular shape) in the visible light image based on the denomination and direction of the banknote determined by the identification process, and the partial image. In addition to generating 6a, as shown in FIG. 5B, the serial number region is cut out in a predetermined shape (for example, rectangular shape) in the fluorescent image to generate the partial image 6b. Then, the degree of coincidence is calculated from the generated partial images 6a and 6b. For example, if the calculated coincidence is equal to or greater than a predetermined threshold, the fluorescent image serial number 3 exists at a position corresponding to the visible light image serial number 4, and if the calculated coincidence is less than the predetermined threshold, the fluorescent image It can be determined that serial number 3 does not exist at a position corresponding to visible light image serial number 4.

Note that the degree of coincidence is an index indicating the degree of similarity between images, and is represented by a value within a finite numerical range, for example, a value between −1 and +1, for example, calculated using a normalized correlation coefficient. Is done. When the normalized correlation coefficient is used, the degree of coincidence is calculated based on the pixels in the entire region to be compared.

Since the fluorescent image serial number 3 is an image of the fluorescent serial number 1b, as described above, it was conventionally difficult to read the fluorescent serial number 1b only from the fluorescent image serial number 3, but on the other hand, Since the optical image serial number 4 is obtained by imaging the visible serial number 1a, detection and reading (character recognition) can be performed in units of symbols of the serial number 1 from only the visible light image serial number 4. Therefore, by performing the position determination step, the fluorescent image serial number 3 can be compared with a more accurate reference of the visible light image serial number 4. As a result, if the fluorescent image serial number 3 is present at a position corresponding to the visible light image serial number 4, the reading result symbol of the visible light image serial number 4, ie, the fluorescent serial number is the same as the visible serial number 1a. Since it can be determined that 1b is described, the fluorescent serial number 1b can be accurately read (character recognition).

If the fluorescent image serial number 3 does not exist at the position corresponding to the visible light image serial number 4, the fluorescent serial number 1b cannot be read with high accuracy. Is possible. That is, for example, when the fluorescent image serial number 3 does not exist at the position corresponding to the visible light image serial number 4, it may be determined that the banknote is a forged ticket.

In the present embodiment, the fluorescent image may be acquired in color. In this case, it is possible to detect the color of the fluorescent image serial number 3, that is, the emission color of the fluorescent serial number 1b, from the color fluorescent image, and the detection result can be used for the authenticity determination of the banknote.

FIG. 6 is a schematic diagram for explaining an image data acquisition mode in the image data acquisition step of the serial number reading method according to the first embodiment. In the present embodiment, as shown in FIG. 6, the resolution of the visible light image and the fluorescent image is increased in the sub-scanning, and the line width of the serial number 1 (visible serial number 1a), particularly the line width in the sub-scanning direction. It is preferable to detect image data of one line or more. That is, the resolution in the sub-scanning direction of the line sensor when irradiated with visible light and excitation light is not more than the line width of the serial number (visible serial number 1a) written on the banknote, particularly the line width in the sub-scanning direction. It is preferable that Thereby, since detection accuracy can be improved about any of visible light image serial number 4 and fluorescence image serial number 3, the reading precision of fluorescence serial number 1b can be improved more.

In the present embodiment, it is desirable that the resolutions in the main scanning direction of the visible light image data and the fluorescence image data match each other, but it is not always necessary to match, and the visible light image data and the fluorescence image data are not necessarily the same. Although it is desirable that the resolutions in the sub-scanning direction also match each other, they do not necessarily need to match.

In the present embodiment, it is preferable that the number of lines where the light source that emits the excitation light is turned off is as small as possible. For example, as shown in FIG. 6, it is preferable that the number of lines is 2 or less, and it is preferable that excitation light is emitted once in 3 times of light sequentially irradiated by the line sensor. Thereby, since the signal component by phosphorescence can be added to the output signal of the line sensor in addition to the signal component by fluorescence in the narrow sense of serial number 1, it is advantageous for extracting the fluorescent image serial number 3 from the fluorescence image. Therefore, the reading accuracy of the fluorescent serial number 1b can be further improved.

In this embodiment, the serial number obtained by character recognition (optical character recognition: OCR) of the serial number region of the fluorescent image, and the serial number obtained by character recognition of the serial number region of the visible light image It may be determined whether or not. In this case, since this determination result can be used for the authenticity determination of a banknote, the authenticity determination capability of a banknote can be improved.

Moreover, in this embodiment, as shown in FIG. 6, it is preferable that the line sensor 120 irradiates visible light and excitation light continuously, and acquires visible light image data and fluorescence image data continuously. . Thereby, since the visible light image and fluorescence image of the banknote conveyed can be imaged continuously, the shift | offset | difference of the banknote position in both images can be minimized. Therefore, it is possible to further improve the reading accuracy of the fluorescent serial number 1b read based on the visible light image data and the fluorescent image data.

In the present embodiment, the visible light image data used for reading the serial number may be transmitted light image data of banknotes, but is preferably reflected light image data from the viewpoint of reading accuracy of serial number 1. . From the same viewpoint, the fluorescence image data used for reading the serial number may be data acquired by a light receiving unit located on the opposite side of the light source (based on the banknote) with respect to the banknote. On the other hand, it is preferable that the data is acquired by the light receiving unit located on the same side as the light source (based on the banknote).

(Banknote image forming method by serial number reader)
Next, the concept of the image forming method of banknotes by the serial number reading device 100 according to the present embodiment will be described with reference to FIG. FIG. 7 is a diagram showing a part that is characteristic of the configuration of the light emitting unit 142 and the light receiving unit 144 related to the image formation of banknotes.

The light emitting unit 142 includes a blue light source having a wavelength band of 400 nm to 500 nm, a green light source having a wavelength band of 500 nm to 600 nm, a red light source having a wavelength band of 600 nm to 700 nm, an infrared light source having a wavelength band of 700 nm to 1000 nm, These light sources are turned on at the same lighting timing. The light sources in the four wavelength bands of the light emitting unit 137 are turned on at the same lighting timing to irradiate the bill, and the reflected light is condensed on the light receiving unit 144 by the condensing lens 143 and collected by the light receiving unit 144. Measure the received light intensity of the reflected light. In addition, the light emitting unit 142 further includes an ultraviolet light source having a wavelength band of 300 nm to 400 nm.

As shown on the right side of FIG. 7, the light receiving unit 144 includes four light receiving elements 144a to 144d, and the four light receiving elements 144a to 144d are four filters (optical filters) having different wavelength bands to be transmitted. Two band-pass filters 147a to 147d are provided. The light receiving element 144a is a band pass filter 147a that passes only light in the wavelength band of 400 nm to 500 nm, the light receiving element 144b is a band pass filter 147b that passes only light in the wavelength band of 500 nm to 600 nm, and the light receiving element 144c is a wavelength band of 600 nm to 700 nm. The band-pass filter 147c that passes only the light in the range and the light receiving element 144d include the band-pass filter 147d that passes only the light in the wavelength band of 700 nm to 1000 nm. The light receiving elements 144a to 144d receive light of different wavelength bands that have passed through the corresponding bandpass filters 147a to 147d.

As a result, even if light of the four wavelength bands is emitted from the light emitting unit 142 to the banknotes at the same emission timing, the reflected light from the banknotes with respect to the irradiated light of the four types of wavelength bands is simultaneously received by the light receiving unit 144. Since the light is filtered by the bandpass filters 147a to 147d corresponding to the respective wavelength bands, it is possible to obtain the received light intensity for each wavelength band by the light receiving elements 144a to 144d.

That is, when the interval at which the light receiving intensity is acquired by the light receiving unit 144 and the bill conveyance speed are equal, in the example shown in FIG. 7, the light reception for each wavelength band is compared with the method of acquiring data by time division. Since the intensity sampling number is quadrupled, it indicates that the resolution in the sub-scanning direction is quadrupled. Moreover, if the resolution of the same level as the method of acquiring data by time division is sufficient, it becomes possible to quadruple the bill conveyance speed.

Further, the light receiving element of the light receiving unit is divided into six, the infrared range of 700 nm to 1000 nm is divided into three, and a light receiving element corresponding to a bandpass filter that passes only light in the divided wavelength range is provided. Then, high-resolution image data for each of the three wavelength bands can be formed for image data during infrared light irradiation.

In the present embodiment, light in four wavelength bands may be turned on one by one in order, and the received light intensity for each wavelength band may be acquired. In that case, it is possible to acquire a feature image of a bill that has a feature in light emission in a wavelength band different from the irradiated light.

(Internal configuration of serial number reading device and banknote identification device)
Next, the internal configurations of the serial number reading device and the banknote recognition device according to the present embodiment will be described. Below, the case where ultraviolet light is irradiated as excitation light is demonstrated. FIG. 8 is a block diagram illustrating an internal configuration of the serial number reading device and the banknote recognition device according to the first embodiment. As illustrated in FIG. 8, the serial number reading device 100 and the banknote identification device 101 include a line sensor 120 that acquires information related to an image of a banknote being conveyed, a storage unit 160, and a control unit 170. In addition to the configuration of the serial number reading device 100, the banknote identification device 101 includes an identification unit 179 of the control unit 170.

As shown in FIG. 8, the line sensor 120 has an upper unit 130 and a lower unit 140. The upper unit 130 and the lower unit 140 are located on opposite sides of the conveyance path 150 where the banknote is conveyed, and acquire information related to the image of the banknote. Moreover, the line sensor 120 irradiates light to reflected data based on reflected light that irradiates and reflects light on one side of the banknote (hereinafter referred to as A side and the opposite side as B side). Thus, transmission data based on the transmitted light transmitted can be acquired.

The storage unit 160 is a storage device composed of a DDR-SDRAM or the like. The storage unit 160 stores determination data 161 necessary for identifying the denomination, authenticity, correctness, and the like. The determination data 161 includes various templates 162 and various threshold values 163. As the template 162, for example, a reference image or the like for comparison with an image obtained by capturing a banknote by the line sensor 120 in order to identify the denomination, authenticity, correctness or the like is stored. Moreover, the value for determining the various feature-values acquired from the banknote in order to identify the money type of a banknote, authenticity, correctness, etc. is preserve | saved as the threshold value 163. The predetermined template 162 and the predetermined threshold value 163 are prepared in advance for the denomination of the banknote processed by the banknote recognition apparatus 101. In addition, the storage unit 160 also stores setting data or the like in which various data measurement methods for identifying bills are set. The storage unit 160 is also used for storing banknote identification results.

The storage unit 160 includes visible reflection raw image data 164, reflected light image data 165, UV fluorescence image data 166, transmitted light image data 167, and UV fluorescence raw image data 168.

The visible reflection raw image data 164 is a reflected light image data based on the reflected light for each wavelength band of the irradiated light obtained by irradiating the A surface of the banknote with visible light by the lower unit 140 and acquired by the sensor included in the lower unit 140. Including. The visible reflection raw image data 164 is image data that has not been subjected to addition averaging, and includes visible light image data.

The reflected light image data 165 is a reflected light based on the reflected light for each wavelength band of the irradiated light obtained by irradiating the A surface of the bill with visible light and infrared light by the lower unit 140 and acquired by the sensor provided in the lower unit 140. Contains image data. The reflected light image data 165 is image data subjected to addition averaging processing, and includes visible light image data and infrared light image data.

The visible light image data used for the serial number reading process described above may be included in the visible reflection raw image data 164 or may be included in the reflected light image data 165. It is preferably included in the image data 165.

The UV fluorescence raw image data 168 includes fluorescence image data for each wavelength band based on the fluorescence emitted from the banknote obtained by irradiating the A surface of the banknote with ultraviolet light by the lower unit 140 and acquired by the sensor included in the lower unit 140. The UV fluorescent raw image data 168 is image data not subjected to addition averaging.

The UV fluorescent image data 166 includes fluorescent image data for each wavelength band based on the fluorescence emitted from the banknote obtained by irradiating the A surface of the banknote with ultraviolet light by the lower unit 140 and acquired by the sensor included in the lower unit 140. The UV fluorescence image data 166 is image data obtained by performing addition averaging processing.

The fluorescence image data used for the serial number reading process described above may be included in the UV fluorescence raw image data 168 or may be included in the UV fluorescence image data 166. The data 166 is preferably included.

The transmitted light image data 167 irradiates the bill with light by turning on the light source provided in the upper unit 130, and transmits the transmitted light through the bill for each wavelength band of the irradiated light acquired by the sensor provided in the lower unit 140. Based transmitted light image data. The transmitted light image data 167 is image data obtained by performing addition averaging processing.

The control unit 170 is a control unit that controls the entire serial number reading device 100 and the bill identifying device 101, and is configured by a logical device such as an FPGA (Field Programmable Gate Array), and is included in the serial number reading device 100. , Image data generation unit 171, line memory 172, light source control unit 173, AFE control unit 174, outer shape extraction unit 175, position determination unit 176, color detection unit 177 and character determination unit 178, and identification unit 179 of the banknote recognition apparatus 101. And have.

The image data generation unit 171 once captures the data acquired from the line sensor 120 into the line memory 172. The line memory 172 includes a plurality of types of line data acquired simultaneously by the line sensor 120. The type of line data is distinguished depending on whether it is data that acquired reflected light or data that acquired transmitted light, a difference in wavelength of irradiated light, and the like. The image data generation unit 171 generates image data corresponding to each type by distributing the data in the line memory 172 for each type of line data. The image data generation unit 171 performs processing such as correction and addition averaging on each type of image data, and converts the generated image data into visible reflection raw image data 164, reflected light image data 165, UV fluorescence. The image data 166 and the transmitted light image data 167 are registered.

The light source control unit 173 controls lighting and extinguishing for each of the plurality of light sources included in the line sensor 120. The AFE control unit 174 performs offset adjustment, input signal sampling setting, data capture timing control, data output setting, and the like for the AFE 145a of the line sensor 120.

The outer shape extraction unit 175 extracts the outer shape (outline) of the banknote based on the transmitted light image data of the banknote acquired by the line sensor 120, and determines the cutting position of the banknote in each image. That is, an area corresponding to a banknote is determined in each image including the banknote and its background. The confirmed bill cutting position information is stored in the storage unit 160 as bill contour information.

As described above, the position determination unit 176 determines whether or not the serial number detected from the fluorescent image data exists at a position corresponding to the serial number detected from the visible light image data.

As described above, the color detection unit 177 detects the color of the serial number detected from the fluorescence image data.

As described above, the character determination unit 178 determines whether or not the serial number obtained by performing character recognition on the fluorescent image matches the serial number obtained by performing character recognition on the visible light image. judge.

The identification unit 179 includes a denomination identification unit 179a, a true / false determination unit 179b, and a fitness determination unit 179c, and performs identification processing using data acquired by the line sensor 120. The denomination identifying unit 179a, the authenticity determining unit 179b, and the integrity determining unit 179c are based on various image data formed based on the data acquired by the line sensor 120, respectively, and the denomination of the banknote, the authenticity determination, Performs damage judgment. The authenticity determination unit 179b determines the authenticity of the bill based on at least the determination results of the position determination unit 176, the color detection unit 177, and the character determination unit 178.

In addition, the identification unit 179 uses the contour information of the banknote obtained by the contour extraction unit 175 when using various images of the banknote photographed by the line sensor 120 in order to identify the denomination, authenticity, correctness, and the like. . For example, the identification unit 179 defines an area corresponding to a banknote as an identification target area in the entire image including the banknote and its background, based on the outline information of the banknote obtained by the outer shape extraction unit 175. The image data in the area is made into a block and identification processing by pattern matching or the like is performed.

(Configuration of line sensor)
Next, the configuration of the line sensor 120 shown in FIG. 8 will be described. FIG. 9 is a cross-sectional view in which the line sensor 120 of the serial number reading device 100 and the banknote recognition apparatus 101 is cut by a plane perpendicular to the banknote transport surface and parallel to the banknote transport direction.

The line sensor 120 includes an upper unit 130 on the B surface side and a lower unit 140 on the A surface side of the banknote shown on the drawing so as to sandwich the transport path 150 for transporting the banknote. The upper unit 130 includes a light emitting unit 131 and a transparent member 136. The lower unit 140 includes light emitting units 142a and 142b (hereinafter collectively referred to as the light emitting unit 142), a condenser lens 143, a light receiving unit 144, a light receiving unit substrate 145, and a transparent member 146.

The light sources of the light emitting units 131 and 142 are configured by a light guide or an LED array. The light emitting unit 142 includes a light source that uses infrared light (IR) with a peak wavelength of 950 nm, a light source that uses red light (R) with a peak wavelength of 650 nm, and a light source that uses green light (G) with a peak wavelength of 550 nm. A light source having a peak wavelength of 450 nm of blue light (B) and a light source having a peak wavelength of 370 nm of ultraviolet light (UV). The light emitted from the light emitting unit 142 is applied to the bill through the transparent member 146, and the light reflected from the bill is collected by the condenser lens 143, received by the light receiving unit 144, and acquired by the light receiving unit 144. The received data is transmitted to the control unit 170 by the light receiving unit substrate 145. The light receiving unit 144 is a line-shaped light receiving sensor extending in a direction perpendicular to the paper surface of FIG. 9, and about 1600 pixel unit units are arranged in a line. The pixel unit includes four light receiving elements 144a to 144d, and each of the light receiving elements 144a to 144d includes band pass filters 147a to 147d that transmit only light in a predetermined wavelength band.

An ultraviolet light cut filter that blocks ultraviolet light may be provided between the conveyance path 150 and the light receiving unit 144. For example, an ultraviolet light cut filter may be deposited on the condenser lens 143, and an ultraviolet light component of 400 nm or less may be cut before the light from the banknote reaches the light receiving unit 144. As a result, the ultraviolet light component reflected from the banknote can be cut, and the amount of visible light obtained upon irradiation with ultraviolet light can be limited to the amount of light emitted by fluorescence. In particular, when the amount of fluorescent light emission of visible light to be acquired is small, the fluorescence emission and phosphorescence emission can be detected with high accuracy.

The light emitting unit 131 has a light source that uses infrared light (IR) with a peak wavelength of 950 nm and a light source that uses green light (G) with a peak wavelength of 550 nm. The light emitted from the light emitting unit 131 is applied to the bill through the transparent member 136 made of transparent glass or resin, and the light transmitted through the bill enters the condenser lens 143 through the transparent member 146 made of transparent glass or resin. The data collected by the condensing lens 143, received by the light receiving unit 144, and acquired by the light receiving unit 144 is transmitted to the control unit 170 by the light receiving unit substrate 145.

Further, there is a conveyance path 150 between the upper unit 130 and the lower unit 140, and the gap between the upper unit 130 and the lower unit 140 is 1 to 3 mm. This is a distance considering that the bill does not cause a jam or the like during conveyance, and that the focal point and the illumination depth can be appropriately configured with optical characteristics. Further, the light receiving unit 144 has a length in the main scanning direction which is a direction perpendicular to the banknote conveyance direction in FIG. 9 is about 200 mm, and has about 1600 pixel unit units. Therefore, the resolution in the main scanning direction is About 200 dpi. Moreover, the conveyance speed of a banknote is 2000 mm / sec.

Next, the correspondence between the arrangement of the light receiving elements 144a to 144d of the light receiving unit 144 of the line sensor 120 according to the present embodiment and the optical filter will be described. FIG. 10 is a diagram illustrating the correspondence between the arrangement of the light receiving elements 144a to 144d of the light receiving unit 144 of the line sensor 120 according to the first embodiment and the optical filter.

As shown in FIG. 4A, the pixel unit of the light receiving unit 144 has four light receiving elements 144a to 144d. The pixel unit has a light receiving element 144a having a band-pass filter 147a that transmits blue light (B) having a wavelength of 400 to 500 nm and a band-pass filter 147b that transmits green light (G) having a wavelength of 500 to 600 nm. A light receiving element 144b, a light receiving element 144c having a bandpass filter 147c that transmits red light (R) having a wavelength of 600 to 700 nm, and a bandpass filter 147d that transmits infrared light (IR) having a wavelength of 700 to 1000 nm. And a light receiving element 144d. Note that the band-pass filter 147d of the light receiving element 144d may transmit a wavelength range exceeding 1000 nm.

As a result, the light receiving unit 144 receives blue light (B) having a wavelength of 400 to 500 nm, green light (G) having a wavelength of 500 to 600 nm, and red light (R) having a wavelength of 600 to 700 nm. And the received light intensity of infrared light (IR) having a wavelength of 700 to 1000 nm can be acquired simultaneously.

Here, as shown in FIG. 10A, an example in which the light receiving elements are arranged in two rows in the banknote conveyance direction and two rows in the direction perpendicular to the conveyance direction has been described. It is not limited to this. As shown in FIG.10 (b), a light receiving element may be arrange | positioned in 1 row in the direction perpendicular | vertical with respect to the conveyance direction of a banknote. Moreover, as shown in FIG.10 (c), a light receiving element may be arrange | positioned at 1 row in the conveyance direction of a banknote.

Next, detailed configurations of the light emitting units 131 and 142 and the condenser lens 143 illustrated in FIG. 9 will be described with reference to FIG. In FIG. 11, the light emitting units 131 and 142a shown in FIG. 9 will be described as an example, but the light emitting unit 142b has the same configuration as the light emitting unit 142a.

FIG. 11A shows a detailed configuration of the light emitting unit 131 shown in FIG. 9, and the light guide 12 extending in the main scanning direction and the LED header 11 serving as a light source on both end faces in the main scanning direction. I have. By irradiating light from both end faces of the light guide 12 with the LED header 11 in the direction of the arrow shown in the drawing, the light guide 12 emits light uniformly at the wavelength of the irradiated light.

FIG. 11B shows a detailed configuration of the light emitting unit 142a shown in FIG. 9, and the light guide 22 and the LED header 21 as a light source are provided on both end faces in the main scanning direction. Regarding light emission from the both end faces of the light guide 22 in the direction of the arrow shown in the drawing by the LED header 21, the light guide 22 emits light uniformly at the wavelength of the emitted light. It is the same as 131. However, the wavelength of light emitted from the LED header 21 is different from the wavelength of light emitted from the LED header 11. Details will be described later.

FIG. 11C shows a detailed configuration of the condenser lens 143 shown in FIG. The condenser lens 143 is a rod lens array including a plurality of rod lenses 31 arranged in an array in the main scanning direction.

11A and 11B, the light emitting units 131 and 142a include LED headers 11 and 21 at both ends of the light guides 12 and 22, respectively. The purpose of this was to secure the light emission intensity of the light guides 12 and 22 by providing light sources at both ends, and to minimize the difference in light emission intensity depending on the location of the light guides 12 and 22. . However, depending on the light emission intensity of the LED elements used for the LED headers 11 and 21 and the performance of the light guides 12 and 22, it is not essential to have the LED headers 11 and 21 at both ends of the light guides 12 and 22.

FIG.11 (d) has shown the light emission part 131 by which the LED header 11 was provided only in the edge part of the one side with respect to the light emission part 131 shown to Fig.11 (a). FIG.11 (e) has shown the light emission part 142a in which the LED header 21 was provided only in the edge part of one side with respect to the light emission part 142a shown in FIG.11 (b).

Next, the arrangement of the LED elements in the LED headers 11 and 21 shown in FIG. 11 will be described with reference to FIG.

FIG. 12 is an example of the arrangement of the LED elements in the LED headers 11 and 21. The LED header 11 shown in FIG. 12 has nine LED elements arranged in 3 rows × 3 columns. The breakdown of the nine LED elements is that four LED elements 11a emit green light (G) with a peak wavelength of 550 nm and five LED elements 11b emit infrared light (IR) with a peak wavelength of 950 nm. The LED element 11a that emits green light (G) and the LED element 11b that emits infrared light (IR) are arranged so as not to be adjacent to each other.

The LED header 21 shown in FIG. 12 has seven LED elements arranged in 1 row × 1 column + 2 rows × 3 columns. The breakdown of the seven LED elements is one LED element 21a emitting blue light (B) having a peak wavelength of 450 nm and one LED element 21b emitting green light (G) having a peak wavelength of 550 nm. One LED element 21c that emits red light (R) with a peak wavelength of 650 nm, one LED element 21d that emits infrared light (IR) with a peak wavelength of 950 nm, and an ultraviolet with a peak wavelength of 370 nm The LED element 21e that emits light (UV) is composed of three pieces.

The LED element 21e that emits ultraviolet light (UV) is intended to acquire fluorescence emission when irradiated with ultraviolet light, and more than other light sources in order to acquire fluorescence with less light quantity than reflected light. It is arranged. Further, the LED element 21e that emits ultraviolet light (UV) is arranged in the second row of the third row as shown in the LED header 21 of FIG.

The LED element 21e that emits ultraviolet light (UV) is provided with a visible light cut filter that cuts visible light components, although not shown. As a result, the visible light component can be cut from the light irradiated by the LED element 21e, and the noise component other than the ultraviolet region of the ultraviolet light (UV) is cut, thereby reflecting other than the fluorescence emission excited from the ultraviolet light. Components can be removed.

Next, the light emission timings of the light emitting units 131 and 142 and the light reception timing of the light receiving unit 144 of the line sensor 120 shown in FIG. 9 will be described. FIG. 13 is a timing chart illustrating the light emission timings of the light emitting units 131 and 142 and the light reception timing of the light receiving unit 144 of the line sensor 120.

As illustrated in FIG. 13, the line sensor 120 obtains data corresponding to the entire surface of the banknote by repeating the cycle with three phases of phases 1 to 3 as one cycle.

In the phase 1, by turning on a light source that makes infrared light (TIR) having a peak wavelength of 950 nm and a green light (TG) that has a peak wavelength 550 nm, infrared light (TIR) and The bill is irradiated with green light (TG), the light transmitted through the bill is received by the light receiving unit 144, the received light intensity (TIR data) of infrared light with a wavelength of 700 to 1000 nm, and green with a wavelength of 500 to 600 nm. The light reception intensity (TG data) of light is acquired.

In Phase 2, a light source that sets the peak wavelength of the light emitting unit 142 to infrared light (RIR) of 950 nm, a light source that sets red light (RR) to a peak wavelength of 650 nm, and green light (RG) that has a peak wavelength of 550 nm By turning on a light source that emits blue light (RB) with a peak wavelength of 450 nm, infrared light (RIR), red light (RR), green light (RG), and blue light (RB) are banknotes. And receiving the light reflected from the banknote by the light receiving unit 144, the received light intensity (RIR data) of infrared light having a wavelength of 700 to 1000 nm and the received light intensity (RR) of red light having a wavelength of 600 to 700 nm. Data), the received light intensity (RG data) of green light having a wavelength of 500 to 600 nm, and the received light intensity (RB data) of blue light having a wavelength of 400 to 500 nm.

In Phase 3, by turning on a light source whose peak wavelength of the light emitting unit 142 is 370 nm ultraviolet light (RUV), the bill is irradiated with ultraviolet light (RUV), and the light receiving unit 144 receives fluorescence from the bill. Received light intensity (RIR-UV data) of infrared light having a wavelength of 700 to 1000 nm, received light intensity of red light having a wavelength of 600 to 700 nm (RR-UV data), and reception of green light having a wavelength of 500 to 600 nm. The intensity (RG-UV data) and the received light intensity (RB-UV data) of blue light having a wavelength of 400 to 500 nm are acquired.

As a result, since the data for fluorescence at the time of ultraviolet light (RUV) irradiation is acquired once every three phases, the ultraviolet light (RUV) extinction is 2 lines or less.

Next, the flow of processing for forming image data based on data acquired by the line sensor 120 shown in FIG. 9 will be described. FIG. 14 is a control block diagram showing a flow of processing for forming image data based on data acquired by the line sensor 120.

Data acquired by the light receiving unit 144 of the line sensor 120 is processed independently and in parallel until image data is formed based on the acquired data.

The light receiving unit 144 has about 1600 pixel unit units, and as shown in FIG. 10, the pixel unit unit receives light in four different wavelength bands (R, G, B, IR). To 144d. The light receiving unit 144 has, for example, about 1600 eight output channels, and information acquired by each pixel unit is sent to an AFE (Analog Front End) 145a in a predetermined order using the eight output channels. Sent.

In the example of FIG. 14, the AFE 145 a receives analog information acquired by about 1600 pixel unit units through eight input channels connected from the output channel of the light receiving unit 144, and adjusts the offset according to the characteristics of the input channel. A / D conversion is performed after adjusting the gain. Further, the data acquired by the light receiving unit 144 digitized by A / D conversion is subjected to pixel output conversion 145b such as rearrangement for transmission to the control unit 170 of the main body, and passed through the LVDS serializer. The LVDS output 145c is performed and transmitted to the control unit 170 of the main body using the LVDS interface. Some AFEs have a built-in LVDS output, and the pixel rearrangement process may be performed by the control unit 170. The data transmission interface may use V-By-One (registered trademark) HS.

The control unit 170 temporarily stores in the line memory 172 the data acquired by the digitized light receiving unit 144 received by the LVDS interface at the LVDS input 171a. Since data is transmitted from the lower unit 140 of the line sensor 120 every time data is acquired by the light receiving unit 144, data for each of the light receiving elements 144 a to 144 d of about 1600 pixel unit units is sent to the line memory 172. They are stored in the order in which they are received. The image data generation unit 171 of the control unit 170 performs wavelength decomposition 171b, which is decomposition of the data stored in the line memory 172 into data according to acquisition conditions corresponding to individual data. Specifically, the decomposition into the data according to the acquisition conditions includes the received light intensity data (RR) of the light reflected by irradiating red light and the received light intensity data (RG) of the light reflected by irradiating green light. , Received light intensity data (RB) of light reflected by irradiating blue light, received light intensity data (RIR) of light reflected by irradiating infrared light, and infrared light emitted fluorescently by irradiating ultraviolet light Received light intensity data (RIR-UV), received light intensity data (RR-UV) of red light emitted fluorescently by irradiating ultraviolet light, and received light intensity data (RG) of green light emitted fluorescently by irradiating ultraviolet light. -UV), received light intensity data (RB-UV) of blue light emitted fluorescently by irradiating ultraviolet light, received light intensity data (TIR) of light transmitted by irradiating infrared light, and irradiated with green light The received light intensity data (TG) of the transmitted light.

In addition, the image data generation unit 171 performs a dark output cut 171c, a gain adjustment 171d, and a bright output correction 171e that is a correction of the bright output level, in accordance with the characteristics of each decomposed data for each acquisition condition. Furthermore, the image data generation unit 171 stores raw image data in the storage unit 160 that is not particularly processed in the reflected visible light image data based on the reflected light when irradiated with visible light (RR, RG, RB) depending on the application. Raw image data that is stored as visible reflection raw image data 164 and that is not particularly processed to fluorescence image data based on fluorescence during ultraviolet light (RUV) irradiation is stored in the storage unit 160 as UV fluorescent raw image data 168. Further, the image data generation unit 171 includes reflected light image data at the time of irradiation with visible light and infrared light (RR, RG, RB, RIR), fluorescent image data at the time of irradiation with ultraviolet light (RUV), and transmitted light (TIR, TG) With respect to the transmitted light image data at the time of irradiation, the addition average image data that is blocked for each wavelength band for noise removal and moire prevention is generated, and the reflected light image data 165 is stored in the storage unit 160. , UV fluorescence image data 166 and transmitted light image data 167 are stored.

(Processing flow of serial number reading device and banknote identification device)
Next, the processing flow of the serial number reading device 100 and the banknote recognition device 101 will be described with reference to FIG. FIG. 15 is a flowchart showing a processing flow of the serial number reading device 100 and the banknote recognition device 101.

First, as described above, the line sensor 120 is used to sequentially irradiate the banknotes to be conveyed with light in a plurality of wavelength bands including visible light and excitation light (for example, ultraviolet light), and thereby visible light image data and fluorescent images. Various image data including data is acquired (image data acquisition step S11).

Next, the outer shape extraction unit 175 extracts the outer shape (outline) of the banknote from the transmitted infrared image, determines the cutout position of the banknote in each image, and stores it in the storage unit 160 as the outline information of the banknote (outer shape). Extraction step S12).

Next, the denomination and direction of the banknote are identified by the various image data formed by the denomination identifying unit 179a based on the data acquired by the line sensor 120 and the outline information of the banknote detected by the outer shape extracting unit 175. (Denomination identification step S13). Thereby, the position of the serial number region 2 in each image data is specified.

Next, the position determination unit 176 determines whether or not the fluorescent image serial number 3 is present at the position corresponding to the visible light image serial number 4 as described above (position determination step S14).

Next, the color detection unit 177 detects the color of the fluorescent image serial number 3 as described above (color detection step S15).

Next, as described above, whether the serial number obtained by performing character recognition on the fluorescent image matches the serial number obtained by performing character recognition on the visible light image as described above. It is determined whether or not (character determination step S16).

Note that the order of processing in the position determination step S14, the color detection step S15, and the character determination step S16 is not particularly limited to the above order, and can be set as appropriate.

Next, the authenticity determination unit 179b determines the authenticity of the banknote based on at least the determination results of the position determination unit 176, the color detection unit 177, and the character determination unit 178 (authentication determination step S17).

And the damage determination part 179c identifies the damage of a banknote by the various image data formed based on the data acquired with the line sensor 120 (damage determination step S18).

(Configuration of banknote handling apparatus)
The configuration of the banknote handling apparatus according to this embodiment will be described with reference to FIGS. The banknote processing apparatus according to the present embodiment may have, for example, the configuration shown in FIG. 16 or FIG. A banknote handling apparatus 200 shown in FIG. 16 includes a hopper 210 on which a plurality of banknotes can be placed, a conveyance path 211 that transports banknotes placed on the hopper 210, a banknote recognition apparatus 101 that performs banknote identification processing, A stacking unit 213 that stacks the banknotes identified by the banknote recognition apparatus 101, and a reject unit 214 that stacks banknotes satisfying a predetermined condition separately from other banknotes. By using the banknote identification device 101 built in such a banknote processing apparatus 200, a plurality of banknotes placed on the hopper 210 are continuously processed, and a fake ticket, a damaged ticket, or a genuine / indeterminate ticket The judged banknote can be returned to the reject unit 214 and sorted.

A bill processing device 300 shown in FIG. 17 is a small bill processing device that is installed on a table and used, and a bill recognition device (not shown) that performs bill recognition processing and a plurality of bills to be processed are stacked. Two hoppers 301 that are placed in a state body and two banknotes that are rejected when the banknotes fed out of the hopper 301 into the housing 310 are reject banknotes such as counterfeits or authenticity uncertain tickets. Reject unit 302, operation unit 303 for inputting instructions from an operator, and four stacking units 306a for sorting and stacking banknotes whose denomination, authenticity, and correctness are identified in housing 310 306d and a display unit 305 for displaying information such as the banknote identification count result and the stacking status of the stacking units 306a to 306d. Of the four stacking units 306a to 306d, the stacking units 306a to 306c store correct bills, and the stacking unit 306d stores damaged bills based on the result of the damage determination by the banknote recognition apparatus 101. In addition, the distribution method of the banknote to the stacking units 306a to 306d can be arbitrarily set.

Note that the banknote processing apparatus 200 shown in FIG. 16 or the banknote processing apparatus 300 shown in FIG. 17 performs denomination identification and authenticity determination in the first process, sorts the banknotes into denominations, and performs the second process. The banknote processing may be performed in two steps, such as determining whether the arranged banknotes are correct or not. Moreover, you may perform authenticity determination with respect to the banknote by which authenticity determination was performed in another place.

As described above, in the embodiment, the serial number detected from the fluorescent image data (fluorescent image serial number 3) corresponds to the serial number detected from the visible light image data (visible light image serial number 4). Since the position determination unit (position determination step) for determining whether or not the image is present is provided, the fluorescent image serial number 3 can be compared with a more accurate reference of the visible light image serial number 4. If the fluorescent image serial number 3 is present at a position corresponding to the visible light image serial number 4, the serial number of the fluorescent light is written with the same symbol as the serial light absorbed serial number as a result of reading with the visible light image data. Therefore, it is possible to improve the reading accuracy (recognition rate) of serial numbers that emit fluorescence. Moreover, since the authenticity determination of a banknote can be performed by the reading result of the serial number which emitted the fluorescence, the authenticity determination capability of a banknote can be improved.

Moreover, since the said embodiment is further provided with the color detection part 177 (color detection step) which detects the color of the serial number (fluorescence image serial number 3) detected from fluorescence image data, this detection result is shown to the truth of a banknote. It can be used for false determination. That is, it is possible to further improve the authenticity determination capability of the banknote.

Moreover, in the said embodiment, since the line sensor 120 has the resolution | decomposability of the subscanning direction when irradiated with visible light and excitation light, all are below the line | wire width of the serial number 1 described in the banknote, visible light Since both the image serial number 4 and the fluorescence image serial number 3 can improve the detection accuracy, it is possible to further improve the reading accuracy of the serial number that emits fluorescence.

In the above embodiment, the serial number obtained by performing character recognition on the fluorescent image based on the fluorescent image data matches the serial number obtained by performing character recognition on the visible light image based on the visible light image data. Since the character determination unit 178 (character determination step) for determining whether or not to perform the determination is further provided, the determination result can be used for determining the authenticity of the banknote. That is, it is possible to further improve the authenticity determination capability of the banknote.

Moreover, in the said embodiment, since the line sensor 120 irradiates visible light and excitation light continuously, the shift | offset | difference of the banknote position in a visible light image and a fluorescence image can be minimized. Therefore, it is possible to further improve the reading accuracy of serial numbers that are fluorescently read and read based on visible light image data and fluorescent image data.

In the above embodiment, the line sensor 120 includes a plurality of filters (bandpass filters 147a to 147d) that transmit light in different wavelength bands, and a plurality of light receiving elements 144a to 144 that receive light that has passed through the plurality of filters. 144d, the resolution in the sub-scanning direction of each image data can be improved, so that the detection accuracy can be improved for both the visible light image serial number 4 and the fluorescence image serial number 3. Therefore, it is possible to further improve the reading accuracy of serial numbers that emit fluorescence.

(Deformation)
In the above embodiment, the case of simultaneously irradiating visible light and infrared light has been described. However, visible light and infrared light may be irradiated at different timings, for example, visible light, excitation light, and infrared light. May be continuously irradiated.

In the above-described embodiment, the case where a plurality of band-pass filters are used as the plurality of filters of the plurality of light receiving elements has been described, but the plurality of filters may be color filters.

In the above embodiment, the case where the LED element that emits red light (R), the LED element that emits green light (G), and the LED element that emits blue light (B) is used has been described. Alternatively, an LED element that emits white light (W) may be used. Also in this case, signals (data) relating to red light (R), green light (G), and blue light (B) can be collected by a plurality of light receiving elements having a plurality of filters that transmit light in different wavelength bands. It is.

As mentioned above, although embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. In addition, the configurations of the respective embodiments may be appropriately combined or changed within a range not departing from the gist of the present invention.

As described above, the present invention is a technique useful for reading serial numbers written on paper sheets.

1 Serial number 1a Visible serial number 1b Fluorescent serial number 2 Serial number area 3 Fluorescent image serial number 4 Visible light image serial number 5a, 5b, 6a, 6b Partial image 11, 21 LED header 11a, 11b, 21a, 21b, 21c, 21d, 21e LED elements 12, 22 Light guide 31 Rod lens 100 Serial number reading device 101 Bill recognition device (paper sheet identification device)
120 Optical line sensor (line sensor)
130 Upper unit 131, 137, 142, 142a, 142b Light emitting part 136, 146 Transparent member 140 Lower unit 143 Condensing lens 144 Light receiving part 144a, 144b, 144c, 144d Light receiving element 145 Light receiving part substrate 145a AFE
145b Pixel output conversion 145c LVDS output 147a, 147b, 147c, 147d Band pass filter 150 Transport path 160 Storage unit 161 Data for determination 162 Template 163 Threshold value 164 Visible reflection raw image data 165 Reflected light image data 166 UV fluorescent image data 167 Transmitted light Image data 168 UV fluorescence raw image data 170 Control unit 171 Image data generation unit 171a LVDS input 171b Wavelength resolution 171c Dark output cut 171d Gain adjustment 171e Bright output correction 172 Line memory 173 Light source control unit 174 AFE control unit 175 Outline extraction unit 176 Position Determination unit 177 Color detection unit 178 Character determination unit 179 Identification unit 179a Denomination identification unit 179b Authenticity determination unit 179c Damage determination unit 200, 300 Bill processing device (paper sheet processing device)
210 Hopper 211 Conveying path 213 Stacking unit 214 Rejecting unit 301 Hopper 302 Rejecting unit 303 Operation unit 305 Display units 306a to 306d Stacking unit 310 Housing

Claims (13)

A serial number reading device that reads serial numbers that are described in paper sheets and that absorbs and emits visible light,
An optical line sensor that sequentially irradiates visible light and excitation light on the serial number area of the conveyed paper sheet, and obtains visible light image data and fluorescent image data of the serial number area;
A position determination unit that determines whether a serial number detected from the fluorescent image data is present at a position corresponding to the serial number detected from the visible light image data;
A serial number reading device comprising: The position determination unit calculates a degree of coincidence by superimposing a fluorescent image based on the fluorescent image data and a visible light image based on the visible light image data, and performs the determination based on the calculated degree of coincidence. The serial number reader according to claim 1. Whether the serial number obtained by performing character recognition on the fluorescent image based on the fluorescent image data matches the serial number obtained by performing character recognition on the visible light image based on the visible light image data. The serial number reading device according to claim 1, further comprising a character determination unit for determining. 2. The optical line sensor according to claim 1, wherein the resolution in the sub-scanning direction when the visible light and the excitation light are irradiated is equal to or less than the line width of the serial number written on the paper sheet. The serial number reading device according to any one of? The serial number reading device according to claim 1, wherein the optical line sensor continuously irradiates the visible light and the excitation light. 6. The optical line sensor according to claim 1, further comprising: a plurality of filters that transmit light of different wavelength bands; and a plurality of light receiving elements that receive light transmitted through the plurality of filters. The serial number reading device according to the above. The serial number reading device according to claim 6, further comprising a color detection unit that detects a color of the serial number detected from the fluorescence image data. The serial number reading device according to claim 1, wherein the excitation light is ultraviolet light. The visible light image data is reflected light image data of the paper sheet,
The said fluorescence image data are acquired by the light-receiving part located in the same side as the light source which irradiates the said excitation light on the basis of the said paper sheets. Serial number reader. The serial number reading device according to claim 1, wherein the optical line sensor further irradiates paper sheets with infrared light. The serial number reading device according to any one of claims 1 to 10,
A true / false determination unit that determines the authenticity of the paper sheet based on at least a determination result of the position determination unit;
A paper sheet identification device comprising: A paper sheet processing apparatus comprising the paper sheet identification apparatus according to claim 11. A serial number reading method for reading serial numbers described in paper sheets and absorbing visible light and emitting fluorescence,
Image data acquisition step of sequentially irradiating visible light and excitation light to the serial number area of the conveyed paper sheet by the optical line sensor to acquire visible light image data and fluorescent image data of the serial number area;
A position determination step for determining whether a serial number detected from the fluorescent image data is present at a position corresponding to the serial number detected from the visible light image data;
A serial number reading method comprising:

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