JP6009992B2 - Paper sheet identification device and optical sensor device - Google Patents

Description

  The present invention relates to a paper sheet identification device for identifying a paper sheet including a fluorescent image (hereinafter also referred to as a “fluorescence emission image”), particularly as a paper sheet such as a banknote or a securities. is there.

  In order to identify a paper sheet including a fluorescence emission image, for example, an optical line sensor device described in Patent Document 1 is used as an apparatus for detecting a pattern of a paper sheet image. The optical line sensor device disclosed in Patent Document 1 emits fluorescence emitted from a paper sheet by irradiating the detection target paper sheet with ultraviolet light via each color filter of R, G, B, and each light receiving element of the sensor module. This is a device that detects the pattern of the fluorescence image of each color by receiving the light. The pattern of the fluorescence image of each color detected by the optical line sensor device is used for identifying paper sheets.

JP 2012-68731 A

  However, there are various fluorescent materials used in paper sheets, and there are various fluorescent colors. For example, there are those that fluoresce with visible light of different monochromatic wavelengths such as red, green, yellow, and blue, and there are those that fluoresce with visible light mixed with wavelengths of a plurality of colors. In addition, there are fluorescent substances made of organic substances and those made of inorganic substances such as rare earths, and the fluorescent wavelength and spectral distribution are different. For example, even if the peak wavelengths of fluorescence are the same, the spectral distribution of fluorescence differs due to the difference between organic and inorganic substances. In general, the spectral distribution of an organic fluorescent material is wide and gentle, and the inorganic fluorescent material is narrow and steep.

  Therefore, in the conventional optical line sensor device described in Patent Document 1, it is difficult to detect the above-described various fluorescent color differences in detail, and the detection accuracy of the fluorescence emitted by the paper sheets is difficult. However, it was not sufficient in terms of the accuracy of paper sheet identification based on the difference in fluorescence.

  An object of the present invention is to provide a paper sheet identification device that improves the detection accuracy of fluorescence emitted by a paper sheet and improves the identification accuracy of the paper sheet.

  In order to solve the above-described problem, a paper sheet identification apparatus according to the present invention includes an optical sensor unit and an identification unit that identifies the paper sheet. The optical sensor unit includes a transport path, a light source unit, and a spectroscope that splits fluorescence along a first direction perpendicular to the transport direction along a second direction perpendicular to the first direction; A light receiving unit having a plurality of light receiving elements arranged in a grid pattern along the first direction and the second direction, a signal processing unit for outputting a fluorescence spectral image signal corresponding to the spectral light of the fluorescence, Is provided. The identification unit identifies the paper sheet based on the fluorescence spectral image signal output from the optical sensor unit.

  According to the present invention, the difference in fluorescent color emitted from a paper sheet can be distinguished with high accuracy, and the paper sheet can be identified with high accuracy.

It is explanatory drawing which shows schematic structure of the banknote identification device as Example 1. FIG. It is explanatory drawing which shows schematic structure of an optical sensor part. It is explanatory drawing which shows the relationship between a light-receiving part and the spectral light from the spectrometer irradiated to the light-receiving surface of a light-receiving part. It is explanatory drawing which shows the example of the line-shaped block of the banknote divided by the fixed conveyance distance unit. It is explanatory drawing which shows an example of the spectral image read by the light-receiving part. It is explanatory drawing which shows another example of the spectral image read by the light-receiving part. It is explanatory drawing which shows another example of the spectral image read by the light-receiving part. It is explanatory drawing which showed the example of the fluorescence spectral distribution detected in the position coordinate shown in FIG.7 (b). It is explanatory drawing which shows an example of the fluorescence image which represented the banknote obtained by combining the spectral image of the banknote read for every line-shaped block with the specific fluorescence color. It is explanatory drawing which shows schematic structure of the optical sensor part of the banknote identification device of Example 2. It is explanatory drawing shown about switching of light emission of ultraviolet light and light emission of white light. It is explanatory drawing which shows the example of the reflection spectral image and the fluorescence spectral image which were read in the time division by the light-receiving part.

  Hereinafter, as an embodiment of the paper sheet identification apparatus of the present invention, a banknote identification apparatus that uses a banknote as an identification target among paper sheets such as banknotes, securities, and checks will be described as an example. The banknote recognition apparatus is built in various apparatuses that handle banknotes such as an automatic transaction apparatus such as an ATM (Automated Teller Machine) installed in a financial institution, a settlement machine, and a ticket vending machine.

  Example 1 describes a banknote identification apparatus that identifies a banknote by reading a pattern of fluorescence emitted from a banknote (also referred to as a “fluorescence image”).

  FIG. 1 is an explanatory diagram illustrating a schematic configuration of a banknote recognition apparatus 10 as the first embodiment. The banknote recognition apparatus 10 includes a transport path 11, a transport drive unit 13, an optical sensor unit 14, a magnetic sensor unit 15, an encoder unit 12, a control unit 16, and the transport drive unit 13, which are sequentially arranged along the transport path 11. Is provided.

  The transport driving unit 13 includes transport rollers 13a and 13b facing in the up and down direction (z direction) installed along the width direction (y direction) of the transport path 11 along the x direction. The transport rollers 13a and 13b are driven to rotate by transmitting a rotational force from a transport motor (not shown). The upper conveyance roller 13a is a drive-side conveyance roller driven by a conveyance motor, and the lower conveyance roller 13b is a driven conveyance roller driven by the rotation of the upper conveyance roller 13a. The transport driving unit 13 sandwiches the banknotes S sequentially guided to the transport path 11 between the pair of transport rollers 13 a and 13 b and transports the banknotes S to the rear end along the transport path 11. Note that the banknote S is transported along the transport path 11 in a horizontally long state that is short in the transport direction (x direction) and long in the width direction (y direction).

  The encoder unit 12 outputs a pulse-shaped clock at each conveyance interval (conveyance cycle) representing a certain conveyance distance as a conveyance timing by the conveyance driving unit 13. The optical sensor unit 14 sequentially reads the pattern of the banknote S to be transported for each transport cycle according to the operation timing based on the clock. The magnetic sensor part 15 discriminate | determines the magnetism of the magnetic ink applied to the banknote S conveyed according to the operation timing based on a clock.

  The control unit 16 controls the operations of the transport drive unit 13, the optical sensor unit 14, and the magnetic sensor unit 15 based on the clock, and the pattern information of the banknote S read by the optical sensor unit 14 and the magnetic sensor 15. Based on the magnetic information of the determined banknote S, the denomination of the banknote, the detection of the number of sheets, and the true / false discrimination of the banknote are performed.

  FIG. 2 is an explanatory diagram showing a schematic configuration of the optical sensor unit 14. The optical sensor unit 14 is disposed in a box-shaped housing 30, and an optical processing substrate 29 on which a light source unit 21, a lens array 25, a spectroscope 26, a light receiving unit 27, and a signal processing unit 28 are mounted. And comprising.

  The light source unit 21 includes a plurality of LEDs 23 that emit ultraviolet light arranged in a line along the y direction, and a light guide lens 22 that diffuses the respective light bundles emitted from the plurality of LEDs 23 and emits them as a bundle of light bundles. . The ultraviolet light emitted from the LED 23 is set to a wavelength that excites the fluorescent substance contained in the banknote S.

  The light guide lens 22 has a planar bottom surface 22b facing the plurality of LEDs 23, and a convex surface 22t extending in the y direction (the width direction of the transport path 11) on the opposite side of the plurality of LEDs 23 with respect to the bottom surface 22b. It is a cylindrical lens. The plurality of LEDs 23 are mounted side by side along the y direction on the LED array substrate 24, and more preferably in the vicinity of the bottom surface 22b so that each emitted light efficiently enters the bottom surface 22b of the light guide lens 22. It arrange | positions so that the injection | emission surface of LED23 may contact the bottom face 22b.

  The light source unit 21 is installed so that light emitted from the light guide lens 22 irradiates a predetermined linear area in the transport path 11. For example, the light source unit 21 irradiates light on a linear irradiation area DL that is elongated in the y direction on the virtual center plane 11x (a plane parallel to the xy plane) of the transport path 11. However, it is installed diagonally so as to face the irradiation area DL on the upstream side of the transport path 11 from a position on the downstream side of the transport path 11. The irradiation area DL is set so as to cover from one end to the other end in the longitudinal direction (y direction) of the bill S being conveyed. Note that the light (hereinafter also referred to as “irradiation light”) that irradiates the line-shaped irradiation area DL is in the form of a line or a band (hereinafter referred to as “line-shaped”) extending in the y direction perpendicular to the transport direction, similarly to the irradiation area DL. It is not limited to light such as “etc.”. If irradiation can be performed so as to cover the irradiation area DL, the irradiation light does not necessarily have to be in a line shape perpendicular to the transport direction. However, considering the light irradiation efficiency, it is substantially parallel to the line direction of the irradiation area DL, that is, within a range substantially perpendicular to the transport direction, for example, within a range of ± 10% with respect to 90 degrees. It is preferable that the irradiation light has a line shape. In addition, the closer to the direction perpendicular to the transport direction, the more preferable, and the irradiation light in the form of a line perpendicular to the transport direction is most preferable. Further, the direction of the line-shaped irradiation area DL is not limited to the direction perpendicular to the conveyance direction, and is within a substantially vertical range, for example, within a range of ± 10% with respect to 90 degrees. There may be. However, the closer to the direction perpendicular to the transport direction, the better, and the most preferable direction is perpendicular to the transport direction.

  The lens array 25 has an optical axis center that extends from the irradiation area DL in the x direction (conveyance direction) and the z direction perpendicular to the y direction, and a plurality of rod lenses that are elongated in the z direction are arranged along the y direction. This is a lens element having the above structure. The reflected light of the light irradiated to the portion of the bill S that has been transported to the irradiation area DL (also referred to as “irradiated portion”) and the fluorescence emitted from the bill S represent an image in the irradiated portion of the bill S. Used as image light. However, in this example, as described below, only fluorescence is used as effective image light. The lens array 25 converges so that an optical image (spectral image) represented by the image light from the banknote S conveyed to the irradiation area DL is formed on the light receiving surface of the light receiving unit 27.

  The spectroscope 26 is disposed between the lens array 25 and the light receiving unit 27, and the line-like (also referred to as “band-like”) image light emitted from the lens array 25 is aligned along a direction perpendicular to the y direction. And is converted into spectral image light having a two-dimensional distribution (planar shape) spread along a direction perpendicular to the y direction. As the spectroscope 26, various prisms, gratings (diffraction gratings) and the like are used. In this example, it is assumed that a triangular prism is used. The two-dimensional distribution-like spectral image light emitted from the spectroscope 26 is a two-dimensional distribution-type spectroscopic image in which a spectral wavelength optical image (spectral wavelength image) for each light having a different wavelength is arranged at a position corresponding to the wavelength. Represents an image. Since the light passing through the spectroscope 26 is refracted more greatly as the wavelength is shorter, it is longer from the short wavelength side in the direction perpendicular to the y direction from the bottom to the top (in the diagonally upward direction in the figure). It is split into light on the wavelength side. Note that the line direction of the line-shaped image light corresponds to the first direction of the present invention, and the direction in which the line-shaped image light is dispersed corresponds to the second direction of the present invention. The direction (second direction) in which the line-shaped image light is dispersed is not limited to the direction perpendicular to the first direction (y direction in this example), but is within a substantially vertical range, For example, the direction may be within a range of ± 10% with respect to 90 degrees. However, the closer to the direction perpendicular to the first direction, the better, and the most preferable direction is perpendicular to the first direction.

  FIG. 3 is an explanatory diagram showing the relationship between the light receiving unit 27 and the spectral image light applied to the light receiving surface of the light receiving unit 27. The light receiving unit 27 is a two-dimensional sensor in which a plurality of light receiving elements 27p are arranged in a main scanning direction (v direction parallel to the y direction) and a sub scanning direction (w direction) perpendicular to the main scanning direction. The light receiving element 27p is a photoelectric conversion element that converts received light into an electromotive force according to its strength, and its operation is controlled by a drive circuit (not shown). As the light receiving unit 27, various two-dimensional sensor ICs incorporating a light receiving element and a drive circuit, for example, a CMOS sensor or a CCD sensor can be used.

  The plurality of light receiving elements 27p of the light receiving unit 27 are arranged in a lattice shape in a plane constituted by a first direction and a second direction which are distribution directions of spectral image light emitted from the spectroscope 26. The spectroscopic light (spectral image light) Ysa emitted from the spectroscope 26 is received. Accordingly, the positions of the light receiving elements 27p arranged in the main scanning direction v indicate coordinates (also referred to as “position coordinates”) indicating the position in the longitudinal direction (y direction) of the banknote S, and the light receiving elements arranged in the sub scanning direction w. The position of 27p indicates coordinates (also referred to as “wavelength coordinates”) representing wavelengths from the long wavelength side to the short wavelength side of the spectral light Ysa.

  In the light receiving unit 27, the light received by each of the light receiving elements 27p is subjected to photoelectric conversion, whereby a spectral optical image represented by the received spectral light (spectral image light) is read as a spectral image. However, as described above, the operation of each light receiving element 27p is performed every cycle of the clock output from the encoder unit 12 (also referred to as “carrying cycle” or “carrying period”) for each fixed carrying distance of the bill S. To be controlled. For this reason, actually, the spectroscopic optical image for each line-shaped (band-shaped) area (block) of the banknote S divided by a certain transport distance unit is sequentially read as a spectroscopic image. Therefore, the resolution of reading in the short direction (conveyance direction, x direction) of the bill S is the conveyance amount (conveyance distance) of the bill S in the conveyance cycle. The resolution of the bill S in the longitudinal direction (direction perpendicular to the transport direction, y direction) corresponds to the number of light receiving elements 27p arranged in the main scanning direction. The number of light receiving elements 27p arranged in the sub-scanning direction corresponds to the resolution of the spectral wavelength. The greater the number of light receiving elements 27p in the main scanning direction, the more the position in the longitudinal direction of the bill S can be identified, and the greater the number of light receiving elements in the sub-scanning direction, That is, the color difference can be identified in detail. Moreover, the position of the banknote S in the short direction (transport direction) can be identified in detail as the transport distance of the banknote S in the transport cycle is shorter.

  FIG. 4 is an explanatory diagram illustrating an example of a line-shaped block of banknotes S divided by a certain transport distance unit. DA (1) to DA (n) indicate line-like blocks that are read in each conveyance cycle.

  The analog signal corresponding to the spectral image read by the light receiving unit 27 is processed in the signal processing unit 28 (FIG. 2) mounted on the optical processing board 29, and various arithmetic / processing processes are performed. Thereby, the various image information read from the banknote S is acquired. Note that the signal processing unit 28 is usually configured by an IC in which circuits for performing the various processes are integrated. Various image information of the banknote S obtained by the signal processing unit 28 is sent to the identification unit 16 a of the control unit 16. The identification unit 16a identifies the banknote S based on the obtained image information.

  In the banknote identification device 10, it demonstrates below based on the image of the banknote S read in the optical sensor part 14, specifically, the spectral image by the fluorescence spectral image light emitted for every line-shaped block of the banknote S. Thus, the banknote S can be identified.

  FIG. 5 is an explanatory diagram illustrating an example of a spectral image read by the light receiving unit 27. FIG. 5A shows a part of the spectral image read by the light receiving unit 27. Each pixel lined up in the sub-scanning direction corresponds to nine bandwidths divided by a bandwidth of 25 nm, and the central wavelengths of each division are 680, 655, 630, 605, 580, 555, 530, 505, 480 nm. It is. In addition, each pixel arranged in the main scanning direction corresponds to the position in the longitudinal direction of the banknote S, but in this example, in order to facilitate the explanation, the pixels in the longitudinal direction of the banknote S are divided at intervals of 20 equal parts. Shown as a region. In FIG. 5A, the darker the color in the pixel, the higher the detected light intensity, that is, the brighter the pixel.

  The spectral image of FIG. 5A shows a state in which a pixel line having a wavelength coordinate corresponding to the center wavelength of 580 nm is detected as a bright pixel line with high light intensity. In this case, for example, as shown in FIG. 5B, a fluorescent image Pfla that emits fluorescence of a color corresponding to the detected wavelength coordinate is formed on the line-shaped block DA of the banknote S from which the spectral image has been read. It can be recognized that it is formed in a line shape (band shape) along the longitudinal direction. Specifically, since the wavelength coordinate of the pixel line detected in the spectral image is a coordinate having a center wavelength of 580 nm, it can be recognized that the fluorescence color emitted from the fluorescence image Pfla is yellow. Further, the brightness of the fluorescent color can be recognized according to the intensity of light detected in each pixel.

  In addition, although the said spectral image demonstrated as an example the fluorescence image which emits yellow fluorescence, it is the same also in the fluorescence image which emits fluorescence of another color. Further, not only a general visible light color of about 380 nm to about 780 nm but also a fluorescent image emitting fluorescence of shorter wavelength ultraviolet light or longer wavelength infrared light can be recognized in the same manner. .

  FIG. 6 is an explanatory diagram illustrating another example of the spectral image read by the light receiving unit 27. The spectral image in FIG. 6A is also shown by cutting out a part of the spectral image read by the light receiving unit 27 as in FIG. This spectral image shows a state in which pixel lines having wavelength coordinates corresponding to center wavelengths of 630 nm, 580 nm, and 530 nm are detected as bright pixel lines having high light intensity. In this case, as in the case of the spectral image described with reference to FIG. 5, for example, as shown in FIG. 6B, the line-shaped block DA of the banknote S from which the spectral image has been read has the detected wavelength coordinates. It can be recognized that the fluorescence image Pflb that emits fluorescence of the corresponding color is formed in a line shape (band shape) along the longitudinal direction of the banknote S. Specifically, the wavelength coordinates of the pixel line detected in this spectral image are center wavelengths of 630 nm, 580 nm, and 530 nm, and therefore the fluorescence colors emitted from the fluorescence image Pflb are three colors of red, yellow, and green. Can be recognized. The brightness of each fluorescent color can be recognized according to the intensity of each light. In this spectral image, the case where three fluorescent colors of red, yellow, and green are emitted has been described as an example, but the same can be recognized when a plurality of other fluorescent colors are emitted.

  As described above, in FIGS. 5 and 6, in the read spectral image, a fluorescent image that emits a fluorescent color indicated by a wavelength coordinate corresponding to a bright pixel line with high light intensity can be recognized, and the fluorescent color emitted from the banknote S and Since the brightness can be detected, it is possible to use this for the identification of the banknote S. Conversely, the presence or absence of a fluorescent image emitting a specific fluorescent color can also be detected by detecting the predetermined specific wavelength coordinate, that is, the light intensity state of the line of the pixel of the specific fluorescent color. Therefore, it is also possible to use this for identification of the banknote S.

  FIG. 7 is an explanatory diagram illustrating still another example of the spectral image read by the light receiving unit 27. The spectral image in FIG. 7A also shows a part of the spectral image read by the light receiving unit 27 in the same manner as in FIGS. 5A and 6A. This spectral image shows a state in which a pixel line at a position coordinate indicating a specific position in the longitudinal direction (y direction) of the banknote S is detected as a bright pixel line with high light intensity. In this case, for example, as shown in FIG. 7 (b), in the line-shaped block DA of the banknote S from which the spectral image is read, at a specific position in the longitudinal direction of the banknote S corresponding to the detected position coordinate, It can be recognized that a fluorescent image Pflc emitting fluorescence is formed. Further, the fluorescence color emitted from the fluorescence image Pflc and its brightness can be recognized in accordance with the detected wavelength coordinate and light intensity. In the read spectral image, the position of a bright pixel with high light intensity can be recognized, and the fluorescent color emitted from the banknote S and the brightness thereof can be detected at that position. Is possible. It is also possible to detect the presence or absence of a fluorescent material that emits a predetermined specific fluorescent color. Furthermore, as will be described below, the fluorescent substance used can be identified from the distribution of the intensity of fluorescent light detected at each wavelength coordinate (hereinafter also referred to as “fluorescence spectral distribution”). .

  FIG. 8 is an explanatory diagram showing an example of the fluorescence spectral distribution detected at the position coordinates shown in FIG. As shown in FIG. 8A, when the fluorescence spectral distribution is steep, it is understood that the fluorescent substance is an inorganic compound. Further, when the fluorescence spectral distribution is gentle as shown in FIG. 8B, it is understood that the fluorescent material is an organic compound. In this way, it is possible to specify the fluorescent substance used based on the shape of the fluorescence wavelength distribution (spectral distribution).

  FIG. 9 is an explanatory diagram showing an example of a fluorescent image in which a banknote S obtained by combining spectral images of banknotes read for each line-shaped block is expressed in a specific fluorescent color. A specific wavelength is obtained by cutting out and combining pixel lines PDA (1) to PDA (n) of specific wavelength coordinates from each spectral image of the banknote S sequentially read for each line-shaped block (see FIG. 4). It is possible to generate a fluorescence image Pfls representing the banknote S only with a fluorescent color having a wavelength corresponding to the coordinates. The fluorescence image Pfls in FIG. 9 shows an example in which rectangular images Pfl1 to Pfl4 that emit fluorescence having a wavelength of 580 nm, that is, yellow fluorescence are formed. Thus, by generating an image in which the banknote S is represented only by a fluorescent color having a wavelength corresponding to a specific wavelength coordinate, the banknote S can be used for identification.

  As described above, in the banknote identification device 10 according to the present embodiment, the fluorescence emitted from the banknote S is split by the optical sensor unit 14, and the position and brightness of the fluorescence of the color represented by the split wavelength are detected in detail. Thus, it is possible to distinguish in detail the difference in color and brightness of the fluorescence. Thereby, the fluorescence pattern (fluorescence image) of the banknote S can be read with high accuracy, and the banknote S can be identified with high accuracy.

  Example 2 reads the fluorescence pattern (fluorescence image) generated from the banknote as in Example 1, and also reads the pattern of reflected light from the banknote (also referred to as “non-fluorescence image”). A banknote recognition apparatus that performs identification will be described.

  FIG. 10 is an explanatory diagram illustrating a schematic configuration of the optical sensor unit 14B of the banknote recognition apparatus 10B according to the second embodiment. The optical sensor unit 14B includes a light source unit 21B instead of the light source unit 21 of the optical sensor unit 14 of the first embodiment. The other configuration is basically the same as that of the first embodiment, and the description of the other configuration is omitted.

  The light source unit 21 </ b> B is provided with an LED 40 that emits normal light having a wide and uniform wavelength distribution characteristic such as natural light, for example, white light, on the end surface 22 s of the light guide lens 22 on the y direction side. The light guide mechanism 41 is provided along the y direction on the bottom surface 22 b of the head 22. However, it is not always necessary to use white light, and any light having a visible wavelength distribution characteristic of light capable of reading the color of the paper sheet S to be identified may be used. In this example, it is assumed that white light is emitted. The light emitted from the LED 40 is incident from the end face 22s and reflected by the light guide mechanism 41, and is emitted from the convex surface 22t so as to irradiate the irradiation area DL. In addition, the light guide mechanism 41 can be comprised with a reflecting plate, for example. The light guide mechanism 41 can also be provided by making the structure of the bottom surface 22b of the light guide lens 22 a total reflection surface that reflects light incident from the LED 40 into the light guide lens 22 in the direction of the convex surface 22t. . Further, a total reflection prism can be provided as the light guide mechanism 41 on the bottom surface 22 b of the light guide lens 22.

  FIG. 11 is an explanatory diagram showing switching between ultraviolet light emission and white light emission. FIG. 11A shows a clock output from the encoder unit 12 for each fixed transport distance of the banknote S, and one period of this clock indicates the transport period of the banknote S. FIG. 11B shows a period in which the transport period of FIG. 11A is time-divided and the LED 40 is turned on and white light is emitted in the first half of the transport cycle. FIG. 11 (a) shows a period in which the conveyance cycle of 11 (a) is time-divided and the LED 23 is turned on in the latter half of the conveyance cycle to emit ultraviolet light. In addition, lighting of these LED23 and LED40 is performed by the lighting control circuit (not shown) mounted in the LED array board | substrate 24. FIG.

  In the first half of the white light emission period shown in FIG. 11B, the spectral light (“reflection”) of the reflected light of white light (also referred to as “reflected image light” or “non-fluorescent image light”) irradiated on the banknote S is shown. Spectral optical image represented by “spectral light” or “non-fluorescent spectroscopic light” or “reflected spectroscopic image light” or “non-fluorescent spectroscopic image light” is a spectroscopic image (“reflected spectroscopic image” or “non-fluorescent spectroscopic image”). Also referred to as “spectral image”. Further, in the latter half ultraviolet light emission period shown in FIG. 11C, the spectroscopic optics represented by the fluorescent spectral light (also referred to as “fluorescent spectroscopic light” or “fluorescent spectroscopic image light”) as in the first embodiment. The image is read as a spectral image (also referred to as “fluorescence spectral image”). That is, in a single reading process in which the bill S is transported and the information of the bill S is read, a normal reflection spectroscopic image and fluorescence spectroscopy are obtained by time-sharing the transport cycle divided for each constant transport distance of the bill S. Both images can be read.

  FIG. 12 is an explanatory diagram illustrating an example of a reflection spectroscopic image and a fluorescence spectroscopic image read by the light receiving unit 27 in a time-sharing manner. The reflection spectroscopic image of FIG. 12A and the fluorescence spectroscopic image of FIG. 12B are spectroscopic images read by line-shaped blocks (see FIG. 4) corresponding to the same transport cycle of the banknote S. 12A and 12B, a part of the spectral image read by the light receiving unit 27 is cut out as in FIGS. 5A, 6A, and 7A. It shows.

  In the reflection spectral image of FIG. 12A, the darker the color in the pixel, the brighter the amount of reflection. Therefore, the pixel areas Aw1 and Aw2 have a larger reflection amount and a brighter state than the peripheral pixel area Aw3. From this, as shown in FIG.12 (c), the center wavelength is 505n-605nm in the pixel position corresponding to pixel area Aw1 among the linear blocks DA of the banknote S from which the reflection spectral image was read. It can be recognized that an image Pwa including a color of brightness corresponding to the light intensity in each wavelength region is formed. Further, it can be recognized that an image Pwb including a color of brightness corresponding to each light intensity in the wavelength range of 580 nm to 630 nm is formed at the pixel position corresponding to the pixel region Aw2.

  Further, the fluorescence spectroscopic image of FIG. 12B indicates that the darker the color in the pixel, the brighter the amount of fluorescence. Therefore, the pixel region Afl1 shows a state in which fluorescence with a center wavelength of 580 nm is detected, and the image region Afl2 shows a state in which fluorescence with a center wavelength of 630 nm is detected. From this, as shown in FIG.12 (c), among the line-shaped block DA of the banknote S from which the fluorescence spectral image was read, in the pixel position corresponding to pixel area Afl1, Afl2, yellow and red fluorescence It can be recognized that an image Pfld that emits is formed.

  In the reflection spectroscopic image, the brightness of the color corresponding to each dispersed wavelength can be recognized in detail, so that the color difference can be distinguished in detail, and the banknote S can be distinguished based on the color difference. Can be identified with high accuracy. Similarly, in the fluorescence spectroscopic image, it is possible to distinguish the difference in fluorescence color in detail, and it is possible to identify the banknote S with high accuracy based on the difference in color. Further, by combining the identification of the banknote S with the reflection spectral image and the identification of the banknote S with the fluorescence spectral image, the banknote S can be identified with higher accuracy.

  As described above, in the optical sensor unit 14B of the banknote recognition device 10B of the present embodiment, the reflection spectroscopy of the banknote S is performed by time-sharing the transport cycle in one reading process when the banknote S is transported. The reading of the image and the reading of the fluorescence spectral image of the banknote S can be performed. Thereby, like the conventional banknote identification device, while the general identification of the banknote S is possible based on the read reflection image, the banknote S is identified based on the reflection spectroscopic image. Compared with the identification device, the color difference can be distinguished in detail, and the identification can be performed with high accuracy. Further, similarly to the first embodiment, the color difference can be distinguished in detail based on the read fluorescence spectral image, and the banknote S can be identified with high accuracy. Further, the information obtained from the reflection spectral image and the information obtained from the fluorescent spectral image can be combined to identify the banknote S in a composite manner, and more accurate identification is possible.

  In addition, although the light source part 21B of a present Example is set as the structure which irradiates white light to the irradiation area DL by LED40 which emits white light, the light guide mechanism 41, and the light guide lens 22, several LED23 which emits ultraviolet light. Similarly, a plurality of LEDs that emit white light may be arranged in an array on the bottom surface 22 b of the light guide lens 22, and the irradiation area DL may be irradiated with white light via the light guide lens 22. In this example, an LED is described as an example of the light source. However, the present invention is not limited to the LED, and various light sources can be used.

  In the optical sensor unit 14B of the present embodiment, a reflection optical system in which the light source unit 21B is disposed on the same upper side as the light receiving unit 27 with respect to the transport path 11 is described as an example. However, a transmission optical system in which the light source unit 21B is disposed on the lower side opposite to the light receiving unit 27 with respect to the conveyance path 11 may be used. Further, a transmission optical system may be provided in addition to the reflection optical system. For example, a light source that emits fluorescence may be arranged on the upper side or the lower side of the conveyance path 11, and a light source that emits white light may be arranged on the upper side and the lower side of the conveyance path 11.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment.

DESCRIPTION OF SYMBOLS 10 ... Banknote identification apparatus 10A ... Banknote identification apparatus 10B ... Bill identification apparatus 11 ... Conveyance path 11x ... Virtual center plane 12 ... Encoder part 13 ... Conveyance drive part 13a ... Conveyance roller 13b ... Conveyance roller 14 ... Optical sensor part 14B ... Optical sensor Unit 15 ... Magnetic sensor unit 16 ... Control unit 16a ... Identification unit 21 ... Light source unit 21B ... Light source unit 22 ... Light guide lens 22b ... Bottom surface 22s ... End surface 22t ... Convex surface 25 ... Lens array 26 ... Spectrometer 27 ... Light receiving unit 27p ... Light receiving element 28 ... Signal processing unit 29 ... Optical processing substrate 30 ... Case 41 ... Light guide mechanism S ... Banknote DL ... Irradiation area

Claims (6)

A paper sheet identification device for identifying paper sheets,
An optical sensor unit;
An identification unit for identifying the paper sheet,
The optical sensor unit is
A transport path along which the paper sheets are transported along the transport direction;
The light having a wavelength that causes the fluorescent material contained in the paper sheet to fluoresce with respect to the paper sheet moving in the transport path, as the line-shaped or belt-shaped irradiation light extending in a direction perpendicular to the transport direction. A light source for illuminating a paper sheet;
The line-like fluorescence along the first direction perpendicular to the transport direction, which is incident from the irradiated portion of the paper sheet irradiated with the irradiation light, is reflected in the second direction perpendicular to the first direction. A spectroscope that splits along,
A plurality of light receiving elements arranged in a lattice pattern along the first direction and the second direction, and a light receiving unit that receives the fluorescent spectral light from the spectrometer;
A signal processing unit that outputs a fluorescence spectral image signal corresponding to the fluorescent spectral light received by the light receiving unit;
With
The identification unit, when identifying the paper sheet based on a fluorescence spectral image represented by the fluorescence spectral image signal output from the optical sensor unit , the first direction of the fluorescence spectral image Detecting the intensity and spectral distribution of the fluorescence emitted from the predetermined position of the irradiated portion of the paper sheet based on the line-shaped spectral position image along the second direction corresponding to the predetermined position of A paper sheet identifying apparatus that identifies the paper sheet based on a detection result .   The paper sheet identification device according to claim 1,
  The identification unit obtains a line-shaped spectral wavelength image of a predetermined wavelength included in each of the fluorescent spectral images obtained for each band-shaped region of the paper sheet that is divided at a certain transport distance along the transport direction. By combining, an image showing the paper sheet represented by the fluorescence of the predetermined wavelength is generated, and the paper sheet is identified based on the generated image
  A paper sheet identification device characterized by that.   A paper sheet identification device for identifying paper sheets,
  An optical sensor unit;
  An identification unit for identifying the paper sheet,
  The optical sensor unit is
  A transport path along which the paper sheets are transported along the transport direction;
  The light having a wavelength that causes the fluorescent material contained in the paper sheet to fluoresce with respect to the paper sheet moving in the transport path, as the line-shaped or belt-shaped irradiation light extending in a direction perpendicular to the transport direction. A light source for illuminating a paper sheet;
  The line-like fluorescence along the first direction perpendicular to the transport direction, which is incident from the irradiated portion of the paper sheet irradiated with the irradiation light, is reflected in the second direction perpendicular to the first direction. A spectroscope that splits along,
  A plurality of light receiving elements arranged in a lattice pattern along the first direction and the second direction, and a light receiving unit that receives the fluorescent spectral light from the spectrometer;
  A signal processing unit that outputs a fluorescence spectral image signal corresponding to the fluorescent spectral light received by the light receiving unit;
  With
  The identification unit is configured to identify the paper sheet based on a fluorescence spectral image represented by the fluorescence spectral image signal output from the optical sensor unit, at a certain conveyance distance along the conveyance direction. The paper sheets represented by the fluorescence of the predetermined wavelength by combining the line-shaped spectral wavelength images of the predetermined wavelength included in each of the fluorescence spectral images obtained for each of the band-like regions of the paper sheets to be classified. Is generated, and the paper sheet is identified based on the generated image.
  A paper sheet identification device characterized by that. It is a paper sheet identification device according to any one of claims 1 to 3 ,
The identification unit detects the intensity and color of the fluorescence emitted from the irradiated portion based on a line-shaped spectral wavelength image corresponding to a predetermined wavelength and extending along the first direction in the fluorescent spectral image. Then, the paper sheet identification device is configured to identify the paper sheet based on the detection result. It is a paper sheet identification device according to any one of claims 1 to 4,
The light source unit is
A first light source that emits first light having a wavelength that causes the fluorescent material to fluoresce, and a second light source that emits second light that is non-fluorescent and has a predetermined wavelength range;
In the first period in which a conveyance period corresponding to a certain conveyance amount of the paper sheet is time-divided, the first light is irradiated to the irradiated portion as the irradiation light, thereby the signal processing unit. The fluorescence spectral image signal is output,
In the second period obtained by time-sharing the transport period, the second non-fluorescent light incident from the irradiated portion is irradiated with the second light by irradiating the irradiated portion as the irradiated light. The non-fluorescent spectral light from the spectroscope is received by the light receiving unit, and the non-fluorescent spectral image signal corresponding to the non-fluorescent spectral light received by the light receiving unit is the signal processing unit. Output from
The paper identifying apparatus, wherein the identifying unit identifies the paper based on the fluorescence spectral image signal and the non-fluorescent spectral image signal. It is a paper sheet identification device according to any one of claims 1 to 5,
The identification unit is
The fluorescent substance that emits fluorescence is identified based on the shape of the wavelength distribution of the fluorescence represented by the line-shaped spectral image along the second direction of the fluorescence spectral image, and the paper sheet is identified based on the identification result. A paper sheet identification device characterized in that: