WO2014010719A1 - Magneto-optic hybrid image sensor - Google Patents

Magneto-optic hybrid image sensor Download PDF

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Publication number
WO2014010719A1
WO2014010719A1 PCT/JP2013/069109 JP2013069109W WO2014010719A1 WO 2014010719 A1 WO2014010719 A1 WO 2014010719A1 JP 2013069109 W JP2013069109 W JP 2013069109W WO 2014010719 A1 WO2014010719 A1 WO 2014010719A1
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WO
WIPO (PCT)
Prior art keywords
optical
image
magnetic
light
magneto
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PCT/JP2013/069109
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French (fr)
Japanese (ja)
Inventor
一雄 藤原
林　正明
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グローリー株式会社
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Publication of WO2014010719A1 publication Critical patent/WO2014010719A1/en

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    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07D—HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING
    • G07D7/00—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency
    • G07D7/06—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency using wave or particle radiation
    • G07D7/12—Visible light, infrared or ultraviolet radiation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/00127—Connection or combination of a still picture apparatus with another apparatus, e.g. for storage, processing or transmission of still picture signals or of information associated with a still picture
    • H04N1/00326—Connection or combination of a still picture apparatus with another apparatus, e.g. for storage, processing or transmission of still picture signals or of information associated with a still picture with a data reading, recognizing or recording apparatus, e.g. with a bar-code apparatus
    • H04N1/00339—Connection or combination of a still picture apparatus with another apparatus, e.g. for storage, processing or transmission of still picture signals or of information associated with a still picture with a data reading, recognizing or recording apparatus, e.g. with a bar-code apparatus with an electronic or magnetic storage medium I/O device
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/024—Details of scanning heads ; Means for illuminating the original
    • H04N1/028—Details of scanning heads ; Means for illuminating the original for picture information pick-up
    • H04N1/03—Details of scanning heads ; Means for illuminating the original for picture information pick-up with photodetectors arranged in a substantially linear array
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/024—Details of scanning heads ; Means for illuminating the original
    • H04N1/028—Details of scanning heads ; Means for illuminating the original for picture information pick-up
    • H04N1/03—Details of scanning heads ; Means for illuminating the original for picture information pick-up with photodetectors arranged in a substantially linear array
    • H04N1/0301—Details of scanning heads ; Means for illuminating the original for picture information pick-up with photodetectors arranged in a substantially linear array using a bent optical path between the scanned line and the photodetector array, e.g. a folded optical path
    • H04N1/0305—Details of scanning heads ; Means for illuminating the original for picture information pick-up with photodetectors arranged in a substantially linear array using a bent optical path between the scanned line and the photodetector array, e.g. a folded optical path with multiple folds of the optical path
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N2201/00—Indexing scheme relating to scanning, transmission or reproduction of documents or the like, and to details thereof
    • H04N2201/0008—Connection or combination of a still picture apparatus with another apparatus
    • H04N2201/0063—Constructional details

Definitions

  • the present invention relates to a magneto-optical hybrid image sensor that acquires an optical image and a magnetic image of a paper sheet, and more particularly to a magneto-optical hybrid image sensor that acquires an optical image and a magnetic image by a single image sensor.
  • a magneto-optic effect Faraday effect
  • a magnetic image of a paper sheet including a magnetic material such as magnetic ink or a magnetic thread is acquired using a magneto-optical element that exhibits a Faraday effect. Since the magnetic image is an image according to the magnetic characteristics of the paper sheet, it can be used for detecting the feature amount of the paper sheet.
  • Patent Document 1 discloses a method for acquiring a magnetic image using the Faraday effect.
  • this method after being incident from the upper surface side of the magneto-optical layer and transmitted through the layer, it is reflected by the mirror layer deposited on the lower surface of the magneto-optical layer, propagates in the magneto-optical layer in the reverse direction, and is emitted.
  • Measure light A magnetic image is acquired by utilizing the fact that the polarization direction of light changes according to the magnetization state of the sample when passing through the magneto-optical layer. Based on the magnetic image, the magnetic distribution in the sample is evaluated.
  • Patent Document 2 discloses an apparatus that simultaneously acquires magnetic characteristics and optical characteristics of paper sheets.
  • a magneto-optical layer is provided below a sensor for measuring optical characteristics and magnetic characteristics.
  • a change in light that occurs in the magneto-optical layer in accordance with the magnetic properties of the passing paper sheet is measured as the magnetic characteristics of the paper sheet.
  • a dichroic mirror that transmits a wavelength for acquiring an optical image and reflects a wavelength for acquiring a magnetic image is provided on the lower surface of the magneto-optical layer. At the time of measurement, the magnetic characteristic measurement light is reflected by the lower surface of the magneto-optical layer after passing through the magneto-optical layer.
  • Patent Document 2 it is necessary to satisfy various requirements regarding the apparatus configuration and the component parts in order to measure the magnetic characteristics and the optical characteristics with high accuracy.
  • the light for magnetic property measurement and the light for optical property measurement are distinguished so that the light obtained as the magnetic property can be distinguished from the light obtained as the optical property.
  • the light needs to have different wavelengths.
  • the dichroic mirror for example, a dichroic mirror having a dielectric multilayer coating on the lower surface side of the magneto-optical layer disposed in the measurement window, that is, the surface on which paper sheets pass is used.
  • a protective film for protecting the dielectric multilayer film is further required.
  • the protective film In dichroic mirrors, it is necessary to pick up optical images of paper sheets by transmitting light for measuring optical properties. Therefore, the protective film is required to have high transparency, thinness, wear resistance, etc. It is difficult to realize a protective film that satisfies all the requirements.
  • a sensor for measuring light for measuring magnetic characteristics and a sensor for measuring light for measuring optical characteristics are required. For this reason, for example, if a plurality of line sensors are used, the cost is increased and the size of the measuring device increases. Further, if a lens unit for focusing is required for each of the plurality of line sensors, the cost further increases and the size of the apparatus also increases.
  • the present invention has been made to solve the above-described problems caused by the prior art, and is a low-cost and small-sized magneto-optical hybrid image sensor that acquires a magnetic image and an optical image of a paper sheet with a single image sensor.
  • the purpose is to provide.
  • the present invention is a magneto-optical hybrid image sensor that solves the above-described problems and achieves the object, and is arranged at a magnetic image acquisition position to change the polarization state of incident light to the magnetic characteristics of a paper sheet.
  • a magneto-optical element that is emitted in a changed manner, light that is emitted from the magneto-optical element at the magnetic image acquisition position, and light that is reflected by the paper sheet at an optical image acquisition position different from the magnetic image acquisition position
  • a line sensor for acquiring a magnetic image of the paper sheet passing through the image acquisition position.
  • an optical path length of light from the magnetic image acquisition position to the line sensor and an optical path length of light from the optical image acquisition position to the line sensor are approximately. It is characterized by being identical.
  • the present invention further includes an optical image light source for acquiring an optical image, and a magnetic image light source for acquiring a magnetic image
  • the optical system includes the optical image light source.
  • Two reflectors for bending the optical path of the light emitted from the optical image light source and reflected by the paper on the optical path to the line sensor, and the first beam splitter for transmitting the light incident from the reflector
  • a lens unit for condensing the light transmitted through the first beam splitter and forming an image on the line sensor, and from the magnetic image light source on an optical path from the magnetic image light source to the line sensor.
  • a first polarizing plate for emitting light incident on the magneto-optical element as linearly polarized light; and transmitting light incident from the first polarizing plate to be emitted toward the magneto-optical element.
  • a second beam splitter that reflects light that has passed through the magneto-optical element and reflects the light, and is reflected by the second beam splitter and the first beam splitter, and is collected by the lens unit and reaches the line sensor.
  • a second polarizing plate for allowing a polarized wave having a polarization direction different from the linearly polarized light emitted from the first polarizing plate to pass therethrough.
  • the present invention is characterized in that, in the above-mentioned invention, the magneto-optical element reflects light incident into the element toward the optical system.
  • the present invention is the above invention, wherein the magneto-optical element is provided in a region including the magnetic image acquisition position and the optical image acquisition position, includes the magnetic image acquisition position and does not include the optical image acquisition position.
  • the region has a reflection film that reflects light incident into the element toward the optical system.
  • the line data for forming the magnetic image is formed by turning on the optical image light source and turning off the magnetic image light source while acquiring the line data for forming the optical image.
  • the optical image and the magnetic image are acquired by turning on the magnetic image light source and turning off the optical image light source.
  • the light from the optical image acquisition position and the light from the magnetic image acquisition position different from this position are condensed at the same position, thereby using the single line sensor and the optical image and Since both magnetic images can be acquired, a small magneto-optical hybrid image sensor can be realized at low cost.
  • a single lens unit is obtained by making the optical path length of light from the optical image acquisition position to the line sensor substantially the same as the optical path length of light from the magnetic image acquisition position to the line sensor. Can be used to focus both optical and magnetic images.
  • the optical path length for acquiring the optical image and the optical path length for acquiring the magnetic image are adjusted so as to be substantially the same.
  • a single lens unit can form both a magnetic image and an optical image on the line sensor.
  • a change in the polarization direction of the light before entering the magneto-optical element and the light after passing through and exiting the magneto-optical element can be acquired as a magnetic image. .
  • the magneto-optical element acquires the magnetic image by reflecting the light whose polarization direction is changed according to the magnetic characteristics of the paper sheet toward the optical system that guides the light to the line sensor. can do.
  • a magnetic image is acquired with high accuracy by reflecting light using a reflective film, and a magneto-optical element for acquiring a magnetic image at a magnetic image acquisition position is acquired as an optical image. It can be used as a measurement window in position.
  • the light of the required wavelength is used for the optical image and the magnetic image without limiting the wavelengths of these light sources. And can be acquired separately.
  • FIG. 1 is a schematic diagram for explaining the outline of the magneto-optical hybrid image sensor according to the present embodiment.
  • FIG. 2 is a schematic cross-sectional view showing the structure of the magneto-optical hybrid image sensor according to this embodiment.
  • FIG. 3 is a diagram for explaining another example of the magneto-optical element used in the magneto-optical hybrid image sensor according to the present embodiment.
  • FIG. 4 is a functional block diagram showing a schematic configuration of a paper sheet identification apparatus as an example of an apparatus using the magneto-optical hybrid image sensor according to the present embodiment.
  • FIG. 5 is a diagram for explaining a method of acquiring an optical image and a magnetic image by controlling a light source with the magneto-optical hybrid image sensor according to the present embodiment.
  • FIG. 1 is a schematic diagram for explaining the outline of the magneto-optical hybrid image sensor according to the present embodiment.
  • FIG. 2 is a schematic cross-sectional view showing the structure of the magneto-optical hybrid image sensor according to this embodiment.
  • FIG. 6 is a diagram illustrating different examples of light source control performed by the magneto-optical hybrid image sensor according to the present embodiment.
  • FIG. 7 is a schematic cross-sectional view illustrating an example in which the magneto-optical hybrid image sensor according to the present embodiment includes a line sensor that captures a transmission image.
  • FIG. 8 is a schematic cross-sectional view showing an example in which the magneto-optical hybrid image sensor according to the present embodiment has a light source for transmission images.
  • FIG. 9 is a schematic cross-sectional view illustrating an example in which the magneto-optical hybrid image sensor according to the present embodiment captures a transmission image as an optical image.
  • FIG. 10 is a schematic diagram illustrating an optical image and magnetic image acquisition method according to the related art.
  • FIG. 1 is a schematic diagram for explaining the outline of the magneto-optical hybrid image sensor 1.
  • a magneto-optical hybrid image sensor 1 (hereinafter simply referred to as “hybrid sensor 1”) includes a light source S1 (11) for optical images, a light source S2 (12) for magnetic images, a magneto-optical element 70, and a magnetic sensor.
  • Two polarizing plates P1 (21) and P2 (22) used for acquiring a magnetic image using the Faraday effect by the optical element 70, a line sensor 50 for acquiring an optical image and a magnetic image, and a focal point And a lens unit 40 for forming an image on the line sensor 50.
  • a measurement window by the transparent member 80 is provided in order to take an optical image of the paper sheet 100 passing in the direction of the arrow 200 below the sensor.
  • the material of the transparent member 80 is not particularly limited as long as an image of the paper sheet 100 can be taken.
  • a resin or a glass plate can be used, or a part of the magneto-optical element 70 is used. It may be an aspect. Details of this will be described later.
  • the optical image is acquired by directly imaging the paper sheet 100 from the measurement window formed of the transparent member 80, whereas the magnetic image is acquired by detecting a change in the polarization direction of light by the magneto-optical element 70. . Specifically, this change is detected as a magnetic image by utilizing the fact that the polarization direction of light transmitted through the magneto-optical element 70 changes according to the magnetic characteristics of the paper sheet 100 passing below. .
  • the material of the magneto-optical element 70 is not particularly limited as long as the polarization direction of the light transmitted through the element changes according to the magnetic characteristics of the paper sheet 100 that passes below.
  • a magnetic garnet film is used.
  • a thin film made of yttrium iron garnet (YIG) crystal having a large Faraday effect and having a thickness of about several microns is used.
  • bismuth-substituted yttrium iron garnet or the like in which a part of the thin film crystal is substituted with bismuth (Bi) may be used.
  • the magneto-optical element 70 In the magneto-optical element 70, a part of the light transmitted through the element is reflected on the surface of the magneto-optical element 70, but in order to reflect more light, a reflection film 71 is provided on the magneto-optical element 70. It is desirable to form. Specifically, the reflective film 71 is formed on the lower surface side of the magneto-optical element 70, that is, the side on which the paper sheet 100 passes. The light incident on the magneto-optical element 70 from the upper surface side is reflected by the reflective film 71 without reaching the paper sheet 100 after passing through the element.
  • the hybrid sensor 1 can acquire both a magnetic image and an optical image by the single lens unit 40 and the single line sensor 50. Next, a method for acquiring a magnetic image and an optical image with the hybrid sensor 1 will be described.
  • light used for optical image acquisition is emitted from the optical image light source S ⁇ b> 1 (11), passes through the measurement window formed of the transparent member 80, and is directed toward the paper sheet 100 passing under the hybrid sensor 1. Is irradiated. The light reflected by the paper sheet 100 passes through the transparent member 80 again and is then collected by the lens unit 40 on the line sensor 50. Thereby, an optical image can be acquired by the line sensor 50.
  • the light used for magnetic image acquisition is first emitted from the magnetic image light source S2 (12) and enters the magneto-optical element 70 through the polarizing plate P1 (21).
  • the light transmitted through the element is reflected by the reflective film 71.
  • the light reflected by the reflective film 71 is transmitted through the element again, is emitted from the element, passes through the polarizing plate P2 (22), and is collected by the lens unit 40 on the line sensor 50.
  • the reflection film 71 is not provided, and only the light reflected by the lower surface of the magneto-optical element 70 may be used for acquiring a magnetic image.
  • the polarizing plate P1 (21) and the polarizing plate P2 (22) are arranged so that the linearly polarized light transmitted through the polarizing plate P1 (21) cannot pass through the polarizing plate P2 (22) in the polarization direction.
  • P2 (21 and 22) are arranged so that the polarization directions thereof are orthogonal to each other. For this reason, the light emitted from the magnetic image light source S2 (12) cannot pass through the polarizing plate P2 (22) simply by being transmitted through the magneto-optical element 70 and reflected by the reflection film 71.
  • the Faraday effect by the magneto-optical element 70 is exerted by a magnetic material such as magnetic ink or a magnetic thread contained in the paper sheet 100
  • the polarization direction of light transmitted through the element changes.
  • a part of the light transmitted through the magneto-optical element 70 can be transmitted through the polarizing plate P2 (22).
  • the polarizing plate P ⁇ b> 2 (22) changes in accordance with the magnetic material included in the paper sheet 100 that passes under the magneto-optical element 70, the magnetism of the paper sheet 100.
  • a magnetic image corresponding to the characteristic can be acquired.
  • the arrangement position of the polarizing plate P1 (21) is not particularly limited as long as it is on the optical path from the exit from the magnetic image light source S2 (12) to the incidence on the magneto-optical element 70.
  • the arrangement position of the polarizing plate P2 (22) is not particularly limited as long as it is on the optical path from the exit from the magneto-optical element 70 to the incidence on the line sensor 50.
  • the polarizing direction of the polarizing plate P1 (21) and the polarizing direction of the polarizing plate P2 (22) are not limited to the perpendicular direction, and are arranged to form an angle of about 80 degrees to 100 degrees, for example. It doesn't matter.
  • a magnet unit for applying a bias magnetic field to the region including the magneto-optical element 70 is used inside the hybrid sensor 1 or separately from the hybrid sensor 1.
  • the magnetic field changes due to the passage of the paper sheet 100 including a magnetic material through the bias magnetic field
  • the hybrid sensor 1 is configured to acquire a magnetic image using the change in the polarization direction.
  • Both the light for optical image and the light for magnetic image are condensed on the line sensor 50 by the lens unit 40.
  • the focus is adjusted so that the optical image light reflected from the surface of the paper sheet 100 is collected and an optical image is formed on the line sensor 50.
  • an optical image from the surface of the paper sheet 100 to the lens unit 40 is formed so that a magnetic image can be formed on the same line sensor 50 with the focus adjusted for the optical image.
  • the optical path length of the light for the magnetic image and the optical path length of the light for the magnetic image from the magneto-optical element 70 to the lens unit 40 are set to be substantially the same. For this reason, both the optical image and the magnetic image can be acquired in a focused state by using the single lens unit 40 and the single line sensor 50.
  • the optical path length for capturing an optical image and the optical path length for capturing a magnetic image need not be completely the same, and a difference within the depth of field is allowed. That is, the optical image and the magnetic image formed by the line sensor 50 may be substantially the same as long as the image quality can be maintained.
  • the difference between the optical path lengths of the optical image light and the magnetic image light caused by the distance Hd between the hybrid sensor 1 and the paper sheet 100 passing below is as follows.
  • the optical path length Lo from the transparent member 80 to the lens unit 40 and the optical path length Lm from the magneto-optical element 70 to the lens unit 40 are substantially the same as long as it is absorbed by the depth of field by the lens unit 40. If it is.
  • both the optical image and the magnetic image can be acquired separately while the paper sheet 100 passes once below the hybrid sensor 50.
  • an optical image of the paper sheet 100 passing through this position is acquired with the position where the transparent member 80 is disposed as an optical image acquisition position.
  • the magnetic image of the paper sheet 100 passing through this position is acquired with the position where the magneto-optical element 70 is disposed as the magnetic image acquisition position.
  • the light emission timings of the optical image light source S1 (11) and the magnetic image light source S2 (12) are controlled.
  • a process of acquiring data for one line for forming a magnetic image by the sensor 50 is executed at different timings. That is, only the optical image light source S1 (11) is lit when acquiring an optical image, and only the magnetic image light source S12 (12) is lit when acquiring a magnetic image to acquire an image.
  • an optical image is obtained from a plurality of line data obtained by pulse-lighting the optical image light source S1 (11), and the magnetic image light source S2 is obtained.
  • a magnetic image can be acquired from a plurality of line data obtained by pulse-lighting (12).
  • the optical path length for acquiring the optical image and the optical path length for acquiring the magnetic image are substantially the same, and the optical image light source S1 (11) and the magnetic image light source S2 are used.
  • the light emission timing of (12) both the optical image and the magnetic image can be acquired separately using the single lens unit 40 and the single line sensor 50.
  • the light emission timing of each light source the light does not affect each other in order to acquire each image, so there is no need to change the wavelength of each light source. For this reason, light of an arbitrary wavelength can be selected as light used for each light source.
  • the hybrid sensor 1 can be a small sensor. Moreover, the hybrid sensor 1 can be manufactured at low cost.
  • the hybrid sensor 1 can be made small and inexpensive.
  • FIG. 2 is a schematic cross-sectional view showing the configuration of the hybrid sensor 1.
  • the left side is a configuration for acquiring an optical image
  • the right side is a configuration for acquiring a magnetic image.
  • the hybrid sensor 1 has an optical image light source 11 and a first reflection plate 61 and a second reflection that are mirrors for changing the direction of reflected light reflected from the paper sheet 100.
  • a plate 62, a first beam splitter 31 that transmits light reflected by the second reflecting plate 62, a lens unit 40, and a line sensor 50 are included.
  • the magnetic image light source 12 a first polarizing plate 21 for emitting light from the magnetic image light source 12 as linearly polarized light, and emission from the first polarizing plate 21.
  • the second beam splitter 32 that transmits the transmitted light, the magneto-optical element 70 for changing the polarization direction of the light transmitted through the second beam splitter 32 according to the magnetic characteristics of the paper sheet 100, and the magneto-optical element 70
  • a magnet unit 90 for applying a bias magnetic field and a second polarizing plate 22 for limiting the polarization direction of the light emitted from the magneto-optical element 70 and reaching the line sensor 50 are provided.
  • the first beam splitter 31 and the lens unit 40 for obtaining an optical image are used in the optical path from the light reflected by the second beam splitter 32 to the second polarizing plate 22.
  • a reflective film 71 is formed in a predetermined region that does not include the optical image acquisition position Po and includes the magnetic image acquisition position Pm, and a protective film 72 is formed to protect the reflective film 71. Has been.
  • the first beam splitter 31 has a function of transmitting the light incident from the second reflector 62 and guiding it to the lens unit 40, and a function of reflecting the light incident from the second beam splitter 32 and guiding it to the lens unit 40.
  • the second beam splitter 32 transmits light incident from the first polarizing plate 21 and guides it to the magneto-optical element 70.
  • the second beam splitter 32 reflects light incident from the magneto-optical element 70 and guides it to the first beam splitter 31. With functions. Thereby, both the light from the optical image acquisition position Po and the light from the magnetic image acquisition position Pm can be incident on the lens unit 40.
  • first reflector 61 and the first reflector 61 are arranged so that the optical path length from the optical image acquisition position Po to the first beam splitter 31 is substantially the same as the optical path length from the magnetic image acquisition position Pm to the first beam splitter 31.
  • Two reflectors 62 are installed.
  • the line sensor 50 is a sensor which has arrange
  • a linear light source is used as the optical image light source 11 and the magnetic image light source 12, and a rod lens array is used as the lens unit 40.
  • the line sensor 50 also applies to the first polarizing plate 21 and the second polarizing plate 22, the first beam splitter 31 and the second beam splitter 32, the first reflecting plate 61 and the second reflecting plate 62, and the magnet unit 90. 2 has a shape extending in the depth direction of FIG.
  • the optical image light source 11 for example, LEDs (Light Emitting Diode) and LD (Laser Diode) arranged in a line shape are used.
  • the wavelength of light is not particularly limited, and is determined by the optical image desired to be acquired.
  • the magnetic image light source 12 uses LED or laser light, but the wavelength is not particularly limited.
  • an optical image and a magnetic image are acquired by controlling the light emission timing of the light source. For this reason, it is not necessary to use light of different wavelengths between the optical image light source 11 and the magnetic image light source 12, and a necessary wavelength can be selected and used according to an image to be acquired.
  • the magneto-optical element 70 is a member in which a magnetic garnet film as a magneto-optical layer is formed on a transparent glass substrate or garnet substrate. Since the light can be transmitted, the magneto-optical element 70 can be used as a measurement window as it is in a predetermined region including the optical image acquisition position Po.
  • the reflection film 71 that reflects light transmitted through the magneto-optical element 70 in the predetermined region including the magnetic image acquisition position Pm toward the line sensor 50 is formed by, for example, an electron beam evaporation method or a sputtering method. A metal film is used.
  • the reflective film 71 is protected by a protective film 72.
  • protection by the protective film 72 is unnecessary.
  • a part of one magneto-optical element 70 transmits light to be used for acquiring an optical image, and a part of the magneto-optical element 70 is used to acquire a magnetic image by reflecting light with the reflection film 71.
  • the magneto-optical element 70 realizes a function as a measurement window for acquiring an optical image in addition to a function for acquiring a magnetic image.
  • FIG. 3 is a schematic cross-sectional view showing another method of using the magneto-optical element 70.
  • a mode in which a transparent member 80 such as resin or glass used as a measurement window for capturing an optical image is provided separately from the magneto-optical element 70 for acquiring a magnetic image. It may be.
  • a transparent member 80 such as glass may be used as a substrate, a magneto-optical layer may be formed in a partial region thereof, and the region may be used as the magneto-optical element 70.
  • a mode in which the separately prepared magneto-optical element 70 is used by being bonded to the substrate of the transparent member 80 may be used. Further, as shown in FIG. 3B, in addition to the aspect in which the protective film 72 is provided, as shown in FIG. 3C, the upper surface side of the transparent member 80, that is, the paper sheet 100 and foreign matter may come into contact. It is possible to omit the protective film 72 by disposing the magneto-optical element 70 via the reflective film 71 on the non-side.
  • the hybrid sensor 1 by controlling the lighting timing of the optical image light source 11 and the magnetic image light source 12, the optical image and the magnetic image are separately separated by passing the paper sheet 100 once under the hybrid sensor 1. Can be obtained.
  • the light source control performed at this time is, for example, control performed by the paper sheet identification device using the hybrid sensor 1 in accordance with the conveyance timing of the paper sheet.
  • FIG. 4 is a block diagram illustrating an example of a paper sheet identification device 101 that uses the hybrid sensor 1 to identify the type of paper sheet.
  • the paper sheet identification device 101 controls the lighting timing of the optical image light source 11 and the magnetic image light source 12 of the hybrid sensor 1 in accordance with the conveyance of the paper sheet 100.
  • the line sensor 50 acquires an optical image and a magnetic image, and has a function of identifying the type and authenticity of the paper sheet 100 based on the feature amount extracted from each image.
  • the paper sheet identification apparatus 101 includes a paper sheet transport unit 2 that transports the paper sheet 100 below the hybrid sensor 1, a control unit 3, a storage unit 4, and a communication interface 5.
  • the control unit 3 includes a light source control unit 3 d that controls the optical image light source 11 and the magnetic image light source 12, a conveyance control unit 3 e that controls conveyance of the paper sheet 100, and a signal A output from the line sensor 50.
  • a feature amount is obtained from a signal processing unit 3a that performs D / D conversion, an image generation unit 3b that generates image data from data obtained by the signal processing unit 3a, and an optical image and a magnetic image obtained by the image generation unit 3b.
  • a paper sheet determination unit 3c that determines the type and authenticity of the paper sheet 100 by extracting and comparing with the paper sheet determination template 4a.
  • the storage unit 4 stores a paper sheet determination template 4a used for determining the type and authenticity of the paper sheet 100, and a paper sheet image 4b including an optical image and a magnetic image generated by the image generation unit 3b. Used to store data.
  • the storage unit 4 is also used for storing programs and data necessary for realizing the functions and operations by the control unit 3.
  • the communication interface 5 has a function of outputting the determination result of the paper sheet 100 to an external device and receiving an instruction operation and a setting operation from the external device.
  • the function and operation for extracting the feature amount from the paper sheet image and identifying the type of the paper sheet 100 based on the feature amount can be performed using the conventional technology, so that a detailed description will be given. Omitted.
  • FIG. 5 is a diagram for explaining a method of acquiring an optical image and a magnetic image by alternating lighting control of the optical image light source 11 and the magnetic image light source 12.
  • the optical image light source 11 is turned on and turned on as shown in FIG.
  • the line sensor 50 acquires line data for one line forming an optical image.
  • the line data of the first line acquired in this way is shown as “optical 1” of the optical image line data, but this figure shows the relationship between the lighting of the light source and the line data.
  • the generation timing of the line data is not limited.
  • the process of acquiring line data for forming an image is continued. Based on the acquired line data, an optical image is formed line by line as shown in FIG.
  • an optical image is formed line by line as shown in FIG.
  • the optical image light source 11 may be left on.
  • the paper sheet 100 When the paper sheet 100 is conveyed in the conveyance direction 200 shown in FIG. 2 and reaches the magnetic image acquisition position Pm, acquisition of the magnetic image is started. Specifically, as shown in FIG. 5A, the paper sheet 100 acquires the magnetic image at the timing when the optical image light source 11 is turned off by acquiring line data of the nth line forming the optical image. When the position Pm is reached, the magnetic image light source 12 is then turned on. The line sensor 50 acquires line data (“magnetic 1” in the figure) for one line forming a magnetic image. When the line data for one line of the magnetic image has been acquired, the magnetic image light source 12 is turned off.
  • the light source 11 for optical images is turned on again, and processing for acquiring line data of the (n + 1) th line forming the optical image is started.
  • the optical image light source 11 and the magnetic image light source 12 are alternately turned on to perform processing for sequentially obtaining line data for forming each image.
  • the first line forming the magnetic image as shown in FIG. 5C is obtained.
  • Line data acquisition is started, and thereafter, the process of alternately acquiring the optical image line data and the magnetic image line data line by line is repeated.
  • the process of acquiring the optical image of the entire surface of the paper sheet 100 is completed.
  • the process of acquiring the optical image is completed, only the process of acquiring the magnetic image line data for forming the magnetic image is performed thereafter.
  • the entire paper sheet 100 passes the magnetic image acquisition position Pm shown in FIG. 2, the process of acquiring the magnetic image of the entire surface of the paper sheet 100 is completed.
  • a magnetic image is acquired with light from the magnetic image acquisition position Pm.
  • the alternating lighting control is not limited to the method of alternately lighting the optical image light source 11 and the magnetic image light source 12 one by one.
  • the magnetic image light source 12 may be turned on once.
  • the optical image light source 11 includes a light source for irradiating visible light red (R), green (G), and blue (B) toward the paper sheet 100
  • the light source for magnetic image 12 is turned on once so that each optical image and magnetic image of visible light red, green, and blue To get.
  • each light source when using each light source of visible light, infrared light, and ultraviolet light, similarly, each light source is turned on in turn, and each optical image and magnetic image of visible light, infrared light, and ultraviolet light are displayed. And get.
  • the lighting of each light source is controlled according to the required resolution to obtain each image having the necessary resolution for each light source. can do.
  • a lens unit 41 and a line sensor 51 for capturing a transmission image are arranged on the lower surface side of the conveyed paper sheet 100, and in addition to the reflected image, the line sensor 51 A mode in which a transmission image is acquired may be used.
  • a light source 13 for capturing a transmission image is arranged on the lower surface side of the paper sheet 100, and the line sensor 50 is used to add to the reflected image of the paper sheet 100. It is also possible to obtain a transmission image. In this case, by controlling the lighting timing of each of the optical image light source 11 for the reflection image, the optical image light source 13 for the transmission image, and the magnetic image light source 12 to alternately turn on, A reflection image, a transmission image, and a magnetic image can be acquired.
  • the optical image of the paper sheet 100 may be a mode in which a transmission image is obtained instead of the reflection image.
  • the optical image light source 11 is arranged on the lower surface side of the paper sheet 100, and the alternating lighting control of the light source and the magnetic image light source 12 is performed, whereby the transmission image and the magnetic image of the paper sheet 100 are controlled. Can be obtained.
  • FIGS. 7 to 9 show the mode in which the reflector and the beam splitter are arranged on the optical path from the optical image acquisition position Po and the magnetic image acquisition position Pm to the lens unit 40. It is not limited to this.
  • the configuration of the optical system is not particularly limited as long as light from two different positions can be guided to a single line sensor with substantially the same optical path length. For example, a configuration in which a single optical block such as a prism is used may be used.
  • both the optical image and the magnetic image of the paper sheet 100 can be acquired using the single line sensor 50.
  • the optical path length from the optical image acquisition position Po to the line sensor 50 substantially the same as the optical path length from the magnetic image acquisition position Pm to the line sensor 50, the focus adjustment by the single lens unit 40, In-focus optical and magnetic images can be acquired.
  • the present invention is a useful technique for realizing a low-cost and compact sensor that acquires both an optical image and a magnetic image using the Faraday effect.

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Abstract

A magneto-optic hybrid image sensor which acquires both a magnetic image and an optical image is configured by: a magneto-optical element which is disposed at a magnetic image acquisition position, varies the polarization state of incident light in accordance with magnetic properties of paper sheets, and emits the light; an optics which collects light emitted from the magneto-optical element at the magnetic image acquisition position, and light reflected by paper at an optical image acquisition position different from the magnetic image acquisition position, at the same position; and a line sensor which is disposed at the position where light is collected by the optics, acquires an optical image of the paper which passes through the optical image acquisition position, and acquires a magnetic image of the paper which passes through the magnetic image acquisition position.

Description

光磁気ハイブリッドイメージセンサMagneto-optical hybrid image sensor
　この発明は、紙葉類の光学画像及び磁気画像を取得する光磁気ハイブリッドイメージセンサであって、特に、光学画像及び磁気画像を単一のイメージセンサによって取得する光磁気ハイブリッドイメージセンサに関する。 The present invention relates to a magneto-optical hybrid image sensor that acquires an optical image and a magnetic image of a paper sheet, and more particularly to a magneto-optical hybrid image sensor that acquires an optical image and a magnetic image by a single image sensor.
　近年、紙葉類の特徴量を取得するために、磁気光学効果（ファラデー効果）を利用して磁気画像を取得する装置の開発が試みられている。例えば、ファラデー効果を示す磁気光学素子を利用して、磁気インクや磁気スレッド等の磁性体を含む紙葉類の磁気画像を取得する。磁気画像は、紙葉類の磁気特性に応じた画像となるため、紙葉類の特徴量検出に利用することができる。 In recent years, an attempt has been made to develop an apparatus for acquiring a magnetic image using a magneto-optic effect (Faraday effect) in order to acquire a feature amount of a paper sheet. For example, a magnetic image of a paper sheet including a magnetic material such as magnetic ink or a magnetic thread is acquired using a magneto-optical element that exhibits a Faraday effect. Since the magnetic image is an image according to the magnetic characteristics of the paper sheet, it can be used for detecting the feature amount of the paper sheet.
　例えば、特許文献１には、ファラデー効果を利用して磁気画像を取得する方法が開示されている。この方法では、磁気光学層の上面側から入射して層内を透過した後、磁気光学層の下面に蒸着されたミラー層で反射されて、磁気光学層内を逆方向に伝播して出射する光を計測する。磁気光学層を透過する際に光の偏光方向が試料の磁化状態に応じて変化することを利用して磁気画像を取得する。そして、この磁気画像に基づいて、試料における磁気分布を評価する。 For example, Patent Document 1 discloses a method for acquiring a magnetic image using the Faraday effect. In this method, after being incident from the upper surface side of the magneto-optical layer and transmitted through the layer, it is reflected by the mirror layer deposited on the lower surface of the magneto-optical layer, propagates in the magneto-optical layer in the reverse direction, and is emitted. Measure light. A magnetic image is acquired by utilizing the fact that the polarization direction of light changes according to the magnetization state of the sample when passing through the magneto-optical layer. Based on the magnetic image, the magnetic distribution in the sample is evaluated.
　紙葉類では、光学特性が最も重要な特徴量の１つであるため、紙葉類の評価や識別等を行う際には、磁気特性に加えて光学特性を取得することが望まれる。これに対応する方法として、例えば、特許文献２には、紙葉類の磁気特性及び光学特性を同時に取得する装置が開示されている。 In paper sheets, since optical characteristics are one of the most important feature quantities, it is desirable to acquire optical characteristics in addition to magnetic characteristics when evaluating and identifying paper sheets. As a method corresponding to this, for example, Patent Document 2 discloses an apparatus that simultaneously acquires magnetic characteristics and optical characteristics of paper sheets.
　この装置では、図１０に示すように、光学特性及び磁気特性を計測するセンサ下方に磁気光学層が設けられている。この磁気光学層（図中「磁気光学素子」）を利用して、通過する紙葉類の磁気特性に応じて磁気光学層内で生ずる光の変化を、紙葉類の磁気特性として測定する。磁気光学層の下面には、光学画像を取得するための波長は透過して、磁気画像を取得するための波長は反射するダイクロイックミラーが設けられている。測定時には、磁気特性測定用の光は、磁気光学層を透過した後に磁気光学層の下面で反射される。 In this apparatus, as shown in FIG. 10, a magneto-optical layer is provided below a sensor for measuring optical characteristics and magnetic characteristics. Using this magneto-optical layer (“magneto-optical element” in the figure), a change in light that occurs in the magneto-optical layer in accordance with the magnetic properties of the passing paper sheet is measured as the magnetic characteristics of the paper sheet. A dichroic mirror that transmits a wavelength for acquiring an optical image and reflects a wavelength for acquiring a magnetic image is provided on the lower surface of the magneto-optical layer. At the time of measurement, the magnetic characteristic measurement light is reflected by the lower surface of the magneto-optical layer after passing through the magneto-optical layer.
特許第４４６８０４５号公報Japanese Patent No. 4468045 国際公開第２００６／０１８１９１号International Publication No. 2006/018191
　しかしながら、上記特許文献２に記載された従来技術によれば、磁気特性及び光学特性を高精度に測定するために、装置構成や構成部品に関する様々な要求を満たす必要がある。 However, according to the conventional technique described in Patent Document 2, it is necessary to satisfy various requirements regarding the apparatus configuration and the component parts in order to measure the magnetic characteristics and the optical characteristics with high accuracy.
　まず、磁気特性及び光学特性が同じ位置で測定されるため、磁気特性として得られた光と光学特性として得られた光とを区別できるように、磁気特性測定用の光と光学特性測定用の光を異なる波長とする必要がある。 First, since the magnetic property and the optical property are measured at the same position, the light for magnetic property measurement and the light for optical property measurement are distinguished so that the light obtained as the magnetic property can be distinguished from the light obtained as the optical property. The light needs to have different wavelengths.
　また、ダイクロイックミラーとして、例えば、測定窓に配置された磁気光学層の下面側、すなわち紙葉類が通過する側の面に、誘電体多層膜コーティングを施したものが利用される。ところが、誘電体多層膜は、紙葉類等との接触に対する十分な耐摩耗性を有さないため、さらに、誘電体多層膜を保護する保護膜が必要になる。 Further, as the dichroic mirror, for example, a dichroic mirror having a dielectric multilayer coating on the lower surface side of the magneto-optical layer disposed in the measurement window, that is, the surface on which paper sheets pass is used. However, since the dielectric multilayer film does not have sufficient wear resistance against contact with paper sheets or the like, a protective film for protecting the dielectric multilayer film is further required.
　ダイクロイックミラーでは、光学特性測定用の光を透過させて紙葉類の光学画像を撮像する必要があるため、保護膜には高い透明性、薄膜性、耐摩耗性等が要求されるが、これら全てを満足する保護膜の実現は困難である。 In dichroic mirrors, it is necessary to pick up optical images of paper sheets by transmitting light for measuring optical properties. Therefore, the protective film is required to have high transparency, thinness, wear resistance, etc. It is difficult to realize a protective film that satisfies all the requirements.
　また、磁気特性及び光学特性を異なる位置で測定する場合には、磁気特性測定用の光を計測するためのセンサと、光学特性測定用の光を計測するためのセンサとが必要になる。このため、例えば複数のラインセンサを利用すると、コストがかかる上に計測装置のサイズが大きくなる。また、複数のラインセンサの各々で、焦点を合わせるためのレンズユニットが必要になれば、さらにコストが増大し、装置サイズも大きくなる。 Also, when measuring magnetic characteristics and optical characteristics at different positions, a sensor for measuring light for measuring magnetic characteristics and a sensor for measuring light for measuring optical characteristics are required. For this reason, for example, if a plurality of line sensors are used, the cost is increased and the size of the measuring device increases. Further, if a lens unit for focusing is required for each of the plurality of line sensors, the cost further increases and the size of the apparatus also increases.
　本発明は、上述した従来技術による問題点を解消するためになされたもので、紙葉類の磁気画像及び光学画像を単一のイメージセンサによって取得する低コストかつ小型の光磁気ハイブリッドイメージセンサを提供することを目的とする。 The present invention has been made to solve the above-described problems caused by the prior art, and is a low-cost and small-sized magneto-optical hybrid image sensor that acquires a magnetic image and an optical image of a paper sheet with a single image sensor. The purpose is to provide.
　本発明は、上述した課題を解決し、目的を達成するための、光磁気ハイブリッドイメージセンサであって、磁気画像取得位置に配置されて、入射した光の偏光状態を紙葉類の磁気特性に応じて変化させて出射する磁気光学素子と、前記磁気画像取得位置で前記磁気光学素子から出射する光と、前記磁気画像取得位置とは異なる光学画像取得位置で前記紙葉類によって反射される光とを、同一位置に集光する光学系と、前記光学系によって光が集光される位置に配置されて、前記光学画像取得位置を通過する前記紙葉類の光学画像を取得すると共に前記磁気画像取得位置を通過する前記紙葉類の磁気画像を取得するラインセンサとを備えることを特徴とする。 The present invention is a magneto-optical hybrid image sensor that solves the above-described problems and achieves the object, and is arranged at a magnetic image acquisition position to change the polarization state of incident light to the magnetic characteristics of a paper sheet. A magneto-optical element that is emitted in a changed manner, light that is emitted from the magneto-optical element at the magnetic image acquisition position, and light that is reflected by the paper sheet at an optical image acquisition position different from the magnetic image acquisition position And an optical system for condensing light at the same position, and an optical image of the paper sheet that passes through the optical image acquisition position and is magnetically disposed at a position where light is collected by the optical system. And a line sensor for acquiring a magnetic image of the paper sheet passing through the image acquisition position.
　また、本発明は、上記発明において、前記光学系では、前記磁気画像取得位置から前記ラインセンサに至る光の光路長と、前記光学画像取得位置から前記ラインセンサに至る光の光路長とが略同一であることを特徴とする。 Further, according to the present invention, in the above-described invention, in the optical system, an optical path length of light from the magnetic image acquisition position to the line sensor and an optical path length of light from the optical image acquisition position to the line sensor are approximately. It is characterized by being identical.
　また、本発明は、上記発明において、光学画像を取得するための光学画像用光源と、磁気画像を取得するための磁気画像用光源とをさらに備え、前記光学系は、前記光学画像用光源から前記ラインセンサへ至る光路上に前記光学画像用光源から出射して前記紙葉類で反射された光の光路を折り曲げる２つの反射板と、前記反射板から入射する光を透過させる第１ビームスプリッタと、前記第１ビームスプリッタを透過した光を集光して前記ラインセンサに結像するレンズユニットとを有し、前記磁気画像用光源から前記ラインセンサへ至る光路上に前記磁気画像用光源から前記磁気光学素子へ入射する光を直線偏光として出射するための第１偏光板と、前記第１偏光板から入射する光を透過させて前記磁気光学素子へ向けて出射すると共に前記磁気光学素子内を透過した後に出射した光を反射する第２ビームスプリッタと、前記第２ビームスプリッタ及び前記第１ビームスプリッタで反射されて前記レンズユニットで集光され前記ラインセンサに至る光として、前記第１偏光板から出射した直線偏光とは異なる偏光方向を有する偏光波を通過させるための第２偏光板とを有することを特徴とする。 In the above invention, the present invention further includes an optical image light source for acquiring an optical image, and a magnetic image light source for acquiring a magnetic image, and the optical system includes the optical image light source. Two reflectors for bending the optical path of the light emitted from the optical image light source and reflected by the paper on the optical path to the line sensor, and the first beam splitter for transmitting the light incident from the reflector And a lens unit for condensing the light transmitted through the first beam splitter and forming an image on the line sensor, and from the magnetic image light source on an optical path from the magnetic image light source to the line sensor. A first polarizing plate for emitting light incident on the magneto-optical element as linearly polarized light; and transmitting light incident from the first polarizing plate to be emitted toward the magneto-optical element. A second beam splitter that reflects light that has passed through the magneto-optical element and reflects the light, and is reflected by the second beam splitter and the first beam splitter, and is collected by the lens unit and reaches the line sensor. And a second polarizing plate for allowing a polarized wave having a polarization direction different from the linearly polarized light emitted from the first polarizing plate to pass therethrough.
　また、本発明は、上記発明において、前記磁気光学素子は、該素子内へ入射した光を前記光学系へ向けて反射することを特徴とする。 Further, the present invention is characterized in that, in the above-mentioned invention, the magneto-optical element reflects light incident into the element toward the optical system.
　また、本発明は、上記発明において、前記磁気光学素子は、前記磁気画像取得位置及び前記光学画像取得位置を含む領域に設けられ、前記磁気画像取得位置を含みかつ前記光学画像取得位置を含まない領域に、素子内へ入射した光を前記光学系へ向けて反射する反射膜を有することを特徴とする。 Further, the present invention is the above invention, wherein the magneto-optical element is provided in a region including the magnetic image acquisition position and the optical image acquisition position, includes the magnetic image acquisition position and does not include the optical image acquisition position. The region has a reflection film that reflects light incident into the element toward the optical system.
　また、本発明は、上記発明において、前記光学画像を形成するラインデータを取得する間は前記光学画像用光源を点灯すると共に前記磁気画像用光源を消灯して、前記磁気画像を形成するラインデータを取得する間は前記磁気画像用光源を点灯すると共に前記光学画像用光源を消灯することにより、前記光学画像及び前記磁気画像を取得することを特徴とする。 Further, according to the present invention, in the above invention, the line data for forming the magnetic image is formed by turning on the optical image light source and turning off the magnetic image light source while acquiring the line data for forming the optical image. During the acquisition, the optical image and the magnetic image are acquired by turning on the magnetic image light source and turning off the optical image light source.
　本発明によれば、光学画像取得位置からの光と、この位置とは異なる磁気画像取得位置からの光とを同一位置に集光することにより、単一のラインセンサを利用して光学画像及び磁気画像の両方を取得することができるので、低コストで小型の光磁気ハイブリッドイメージセンサを実現することができる。 According to the present invention, the light from the optical image acquisition position and the light from the magnetic image acquisition position different from this position are condensed at the same position, thereby using the single line sensor and the optical image and Since both magnetic images can be acquired, a small magneto-optical hybrid image sensor can be realized at low cost.
　また、本発明によれば、光学画像取得位置からラインセンサに至る光の光路長と、磁気画像取得位置からラインセンサに至る光の光路長とを略同一とすることにより、単一のレンズユニットを利用して、光学画像及び磁気画像の両方の焦点を合わせることができる。 Further, according to the present invention, a single lens unit is obtained by making the optical path length of light from the optical image acquisition position to the line sensor substantially the same as the optical path length of light from the magnetic image acquisition position to the line sensor. Can be used to focus both optical and magnetic images.
　また、本発明によれば、反射板及びビームスプリッタを利用して、光学画像を取得するための光路長と磁気画像を取得するための光路長とが略同一となるように調整して、単一のレンズユニットによりラインセンサ上に磁気画像及び光学画像の両方を結像させることができる。このとき、２つの偏光板を利用することにより、磁気光学素子への入射前の光と磁気光学素子内を透過して出射した後の光の偏光方向の変化を磁気画像として取得することができる。 Further, according to the present invention, by using the reflector and the beam splitter, the optical path length for acquiring the optical image and the optical path length for acquiring the magnetic image are adjusted so as to be substantially the same. A single lens unit can form both a magnetic image and an optical image on the line sensor. At this time, by using two polarizing plates, a change in the polarization direction of the light before entering the magneto-optical element and the light after passing through and exiting the magneto-optical element can be acquired as a magnetic image. .
　また、本発明によれば、磁気光学素子が、紙葉類の磁気特性に応じて偏光方向が変化した光を、ラインセンサへ光を導く光学系へ向けて反射することにより、磁気画像を取得することができる。 In addition, according to the present invention, the magneto-optical element acquires the magnetic image by reflecting the light whose polarization direction is changed according to the magnetic characteristics of the paper sheet toward the optical system that guides the light to the line sensor. can do.
　また、本発明によれば、反射膜を利用して光を反射することにより高精度に磁気画像を取得すると共に、磁気画像取得位置で磁気画像を取得するための磁気光学素子を、光学画像取得位置で測定窓として利用することができる。 In addition, according to the present invention, a magnetic image is acquired with high accuracy by reflecting light using a reflective film, and a magneto-optical element for acquiring a magnetic image at a magnetic image acquisition position is acquired as an optical image. It can be used as a measurement window in position.
　また、本発明によれば、光学画像用光源及び磁気画像用光源を交番点灯することにより、これらの光源の波長を限定されることなく、光学画像及び磁気画像を、必要な波長の光を利用して別々に取得することができる。 Further, according to the present invention, by alternately turning on the optical image light source and the magnetic image light source, the light of the required wavelength is used for the optical image and the magnetic image without limiting the wavelengths of these light sources. And can be acquired separately.
図１は、本実施形態に係る光磁気ハイブリッドイメージセンサの概要を説明する模式図である。FIG. 1 is a schematic diagram for explaining the outline of the magneto-optical hybrid image sensor according to the present embodiment. 図２は、本実施形態に係る光磁気ハイブリッドイメージセンサの構造を示す断面模式図である。FIG. 2 is a schematic cross-sectional view showing the structure of the magneto-optical hybrid image sensor according to this embodiment. 図３は、本実施形態に係る光磁気ハイブリッドイメージセンサで利用する磁気光学素子の他の例を説明する図である。FIG. 3 is a diagram for explaining another example of the magneto-optical element used in the magneto-optical hybrid image sensor according to the present embodiment. 図４は、本実施形態に係る光磁気ハイブリッドイメージセンサを利用する装置の例として紙葉類識別装置の構成概略を示す機能ブロック図である。FIG. 4 is a functional block diagram showing a schematic configuration of a paper sheet identification apparatus as an example of an apparatus using the magneto-optical hybrid image sensor according to the present embodiment. 図５は、本実施形態に係る光磁気ハイブリッドイメージセンサで光源を制御して光学画像及び磁気画像を取得する方法を説明する図である。FIG. 5 is a diagram for explaining a method of acquiring an optical image and a magnetic image by controlling a light source with the magneto-optical hybrid image sensor according to the present embodiment. 図６は、本実施形態に係る光磁気ハイブリッドイメージセンサで行われる光源制御の異なる例を示す図である。FIG. 6 is a diagram illustrating different examples of light source control performed by the magneto-optical hybrid image sensor according to the present embodiment. 図７は、本実施形態に係る光磁気ハイブリッドイメージセンサが透過画像を撮像するラインセンサを有する例を示す断面模式図である。FIG. 7 is a schematic cross-sectional view illustrating an example in which the magneto-optical hybrid image sensor according to the present embodiment includes a line sensor that captures a transmission image. 図８は、本実施形態に係る光磁気ハイブリッドイメージセンサが透過画像用の光源を有する例を示す断面模式図である。FIG. 8 is a schematic cross-sectional view showing an example in which the magneto-optical hybrid image sensor according to the present embodiment has a light source for transmission images. 図９は、本実施形態に係る光磁気ハイブリッドイメージセンサが光学画像として透過画像を撮像する例を示す断面模式図である。FIG. 9 is a schematic cross-sectional view illustrating an example in which the magneto-optical hybrid image sensor according to the present embodiment captures a transmission image as an optical image. 図１０は、従来技術に係る光学画像及び磁気画像の取得方法を説明する模式図である。FIG. 10 is a schematic diagram illustrating an optical image and magnetic image acquisition method according to the related art.
　以下に添付図面を参照して、この発明に係る光磁気ハイブリッドイメージセンサについて説明する。まず、光磁気ハイブリッドイメージセンサの構成及び画像取得方法の概要について説明する。 Hereinafter, a magneto-optical hybrid image sensor according to the present invention will be described with reference to the accompanying drawings. First, the configuration of the magneto-optical hybrid image sensor and the outline of the image acquisition method will be described.
　図１は、光磁気ハイブリッドイメージセンサ１の概要を説明する模式図である。光磁気ハイブリッドイメージセンサ１（以下、単に「ハイブリッドセンサ１」と記載する）は、光学画像用の光源Ｓ１（１１）と、磁気画像用の光源Ｓ２（１２）と、磁気光学素子７０と、磁気光学素子７０によるファラデー効果を利用して磁気画像を取得するために利用する２つの偏光板Ｐ１（２１）及びＰ２（２２）と、光学画像及び磁気画像を取得するためのラインセンサ５０と、焦点を合わせてラインセンサ５０上に画像を結像するためのレンズユニット４０とを有している。 FIG. 1 is a schematic diagram for explaining the outline of the magneto-optical hybrid image sensor 1. A magneto-optical hybrid image sensor 1 (hereinafter simply referred to as “hybrid sensor 1”) includes a light source S1 (11) for optical images, a light source S2 (12) for magnetic images, a magneto-optical element 70, and a magnetic sensor. Two polarizing plates P1 (21) and P2 (22) used for acquiring a magnetic image using the Faraday effect by the optical element 70, a line sensor 50 for acquiring an optical image and a magnetic image, and a focal point And a lens unit 40 for forming an image on the line sensor 50.
　また、ハイブリッドセンサ１では、図１に示すように、センサの下方で矢印２００の方向へ通過する紙葉類１００の光学画像を撮像するために、透明部材８０による測定窓が設けられている。透明部材８０は、紙葉類１００の画像を撮像することができれば、その材質は特に限定されず、例えば、樹脂やガラス板を利用することもできるし、磁気光学素子７０の一部を利用する態様であっても構わない。これについての詳細は後述する。 Further, in the hybrid sensor 1, as shown in FIG. 1, a measurement window by the transparent member 80 is provided in order to take an optical image of the paper sheet 100 passing in the direction of the arrow 200 below the sensor. The material of the transparent member 80 is not particularly limited as long as an image of the paper sheet 100 can be taken. For example, a resin or a glass plate can be used, or a part of the magneto-optical element 70 is used. It may be an aspect. Details of this will be described later.
　光学画像が透明部材８０から成る測定窓から紙葉類１００を直接撮像して取得されるのに対して、磁気画像は磁気光学素子７０による光の偏光方向の変化を検出することによって取得される。具体的には、下方を通過する紙葉類１００の磁気特性に応じて磁気光学素子７０の素子内を透過する光の偏光方向が変化することを利用して、この変化を磁気画像として検出する。 The optical image is acquired by directly imaging the paper sheet 100 from the measurement window formed of the transparent member 80, whereas the magnetic image is acquired by detecting a change in the polarization direction of light by the magneto-optical element 70. . Specifically, this change is detected as a magnetic image by utilizing the fact that the polarization direction of light transmitted through the magneto-optical element 70 changes according to the magnetic characteristics of the paper sheet 100 passing below. .
　磁気光学素子７０の材質は、下方を通過する紙葉類１００の磁気特性に応じて素子内を透過する光の偏光方向が変化するものであれば特に限定されず、例えば、磁性ガーネット膜を利用する。具体的には、例えば、大きなファラデー効果を示すイットリウム鉄ガーネット（ＹＩＧ）結晶から成る厚さ数ミクロン程度の薄膜を利用する。また、薄膜結晶の一部をビスマス（Ｂｉ）で置換したビスマス置換イットリウム鉄ガーネット等を利用する場合もある。 The material of the magneto-optical element 70 is not particularly limited as long as the polarization direction of the light transmitted through the element changes according to the magnetic characteristics of the paper sheet 100 that passes below. For example, a magnetic garnet film is used. To do. Specifically, for example, a thin film made of yttrium iron garnet (YIG) crystal having a large Faraday effect and having a thickness of about several microns is used. In some cases, bismuth-substituted yttrium iron garnet or the like in which a part of the thin film crystal is substituted with bismuth (Bi) may be used.
　なお、磁気光学素子７０では、素子内を透過した光は、その一部が磁気光学素子７０の表面で反射されるが、より多くの光を反射させるため、磁気光学素子７０に反射膜７１を形成することが望ましい。具体的には、磁気光学素子７０の下面側、すなわち紙葉類１００が通過する側に、反射膜７１を形成する。上面側から磁気光学素子７０に入射した光は、素子内を透過した後、紙葉類１００に達することなく、反射膜７１によって反射される。 In the magneto-optical element 70, a part of the light transmitted through the element is reflected on the surface of the magneto-optical element 70, but in order to reflect more light, a reflection film 71 is provided on the magneto-optical element 70. It is desirable to form. Specifically, the reflective film 71 is formed on the lower surface side of the magneto-optical element 70, that is, the side on which the paper sheet 100 passes. The light incident on the magneto-optical element 70 from the upper surface side is reflected by the reflective film 71 without reaching the paper sheet 100 after passing through the element.
　以上の構成を有することにより、ハイブリッドセンサ１では、単一のレンズユニット４０及び単一のラインセンサ５０により、磁気画像及び光学画像の両方を取得することができる。次に、ハイブリッドセンサ１で磁気画像及び光学画像を取得する方法について説明する。 By having the above configuration, the hybrid sensor 1 can acquire both a magnetic image and an optical image by the single lens unit 40 and the single line sensor 50. Next, a method for acquiring a magnetic image and an optical image with the hybrid sensor 1 will be described.
　まず、光学画像取得に利用される光は、光学画像用光源Ｓ１（１１）から出射され、透明部材８０から成る測定窓を透過して、ハイブリッドセンサ１の下方を通過する紙葉類１００に向けて照射される。紙葉類１００で反射された光は、再び透明部材８０を透過した後、レンズユニット４０によって、ラインセンサ５０に集光される。これにより、ラインセンサ５０で光学画像を取得することができる。 First, light used for optical image acquisition is emitted from the optical image light source S <b> 1 (11), passes through the measurement window formed of the transparent member 80, and is directed toward the paper sheet 100 passing under the hybrid sensor 1. Is irradiated. The light reflected by the paper sheet 100 passes through the transparent member 80 again and is then collected by the lens unit 40 on the line sensor 50. Thereby, an optical image can be acquired by the line sensor 50.
　一方、磁気画像取得に利用される光は、まず、磁気画像用光源Ｓ２（１２）から出射され、偏光板Ｐ１（２１）を経て磁気光学素子７０に入射する。素子内を透過した光は、反射膜７１によって反射される。反射膜７１で反射された光は、再び素子内を透過して素子から出射して、偏光板Ｐ２（２２）を経て、レンズユニット４０によってラインセンサ５０に集光される。なお、反射膜７１を設けず、磁気光学素子７０の下面で反射される光のみを磁気画像の取得に利用してもよい。 On the other hand, the light used for magnetic image acquisition is first emitted from the magnetic image light source S2 (12) and enters the magneto-optical element 70 through the polarizing plate P1 (21). The light transmitted through the element is reflected by the reflective film 71. The light reflected by the reflective film 71 is transmitted through the element again, is emitted from the element, passes through the polarizing plate P2 (22), and is collected by the lens unit 40 on the line sensor 50. Note that the reflection film 71 is not provided, and only the light reflected by the lower surface of the magneto-optical element 70 may be used for acquiring a magnetic image.
　偏光板Ｐ１（２１）及び偏光板Ｐ２（２２）は、偏光板Ｐ１（２１）を透過した直線偏光が、その偏光方向のままでは偏光板Ｐ２（２２）を透過できないように、各偏光板Ｐ１及びＰ２（２１及び２２）の偏光方向が直交するように配置されている。このため、磁気画像用光源Ｓ２（１２）から出射した光は、単に磁気光学素子７０内を透過して反射膜７１で反射されただけでは、偏光板Ｐ２（２２）を透過することができない。しかし、紙葉類１００に含まれる磁気インクや磁気スレッド等の磁性体によって、磁気光学素子７０によるファラデー効果が発揮されると、素子内を透過する光の偏光方向が変化する。この結果、磁気光学素子７０を透過した光の一部が偏光板Ｐ２（２２）を透過できるようになる。このように、磁気光学素子７０の下方を通過する紙葉類１００に含まれる磁性体に応じて偏光板Ｐ２（２２）を透過する光が変化することを利用して、紙葉類１００の磁気特性に応じた磁気画像を取得することができる。 The polarizing plate P1 (21) and the polarizing plate P2 (22) are arranged so that the linearly polarized light transmitted through the polarizing plate P1 (21) cannot pass through the polarizing plate P2 (22) in the polarization direction. And P2 (21 and 22) are arranged so that the polarization directions thereof are orthogonal to each other. For this reason, the light emitted from the magnetic image light source S2 (12) cannot pass through the polarizing plate P2 (22) simply by being transmitted through the magneto-optical element 70 and reflected by the reflection film 71. However, when the Faraday effect by the magneto-optical element 70 is exerted by a magnetic material such as magnetic ink or a magnetic thread contained in the paper sheet 100, the polarization direction of light transmitted through the element changes. As a result, a part of the light transmitted through the magneto-optical element 70 can be transmitted through the polarizing plate P2 (22). As described above, by utilizing the fact that the light transmitted through the polarizing plate P <b> 2 (22) changes in accordance with the magnetic material included in the paper sheet 100 that passes under the magneto-optical element 70, the magnetism of the paper sheet 100. A magnetic image corresponding to the characteristic can be acquired.
　なお、偏光板の配置について、偏光板Ｐ１（２１）の配置位置は、磁気画像用光源Ｓ２（１２）を出射してから磁気光学素子７０に入射する迄の光路上であれば特に限定されず、偏光板Ｐ２（２２）の配置位置についても同様に、磁気光学素子７０を出射してからラインセンサ５０に入射する迄の光路上であれば特に限定されない。また、偏光板Ｐ１（２１）の偏光方向と偏光板Ｐ２（２２）の偏光方向とが直交する態様に限定されるものではなく、例えば、８０度～１００度程度の角度を成すように配置されても構わない。 Regarding the arrangement of the polarizing plate, the arrangement position of the polarizing plate P1 (21) is not particularly limited as long as it is on the optical path from the exit from the magnetic image light source S2 (12) to the incidence on the magneto-optical element 70. Similarly, the arrangement position of the polarizing plate P2 (22) is not particularly limited as long as it is on the optical path from the exit from the magneto-optical element 70 to the incidence on the line sensor 50. Further, the polarizing direction of the polarizing plate P1 (21) and the polarizing direction of the polarizing plate P2 (22) are not limited to the perpendicular direction, and are arranged to form an angle of about 80 degrees to 100 degrees, for example. It doesn't matter.
　また、図１には示していないが、ハイブリッドセンサ１の内部又はハイブリッドセンサ１とは別に、磁気光学素子７０を含む領域にバイアス磁界を印加するための磁石ユニットが利用される。このバイアス磁界内を、磁性体を含む紙葉類１００が通過することによって磁界が変化すると、磁気光学素子７０のファラデー効果によって磁気光学素子７０から出射して偏光板Ｐ２（２２）に入射する光の偏光方向が変化する。ハイブリッドセンサ１は、この偏光方向の変化を利用して磁気画像を取得するように構成されている。 Although not shown in FIG. 1, a magnet unit for applying a bias magnetic field to the region including the magneto-optical element 70 is used inside the hybrid sensor 1 or separately from the hybrid sensor 1. When the magnetic field changes due to the passage of the paper sheet 100 including a magnetic material through the bias magnetic field, the light emitted from the magneto-optical element 70 by the Faraday effect of the magneto-optical element 70 and incident on the polarizing plate P2 (22). Changes the polarization direction. The hybrid sensor 1 is configured to acquire a magnetic image using the change in the polarization direction.
　光学画像用の光と磁気画像用の光は、共に、レンズユニット４０によってラインセンサ５０に集光される。レンズユニット４０では、紙葉類１００表面で反射された光学画像用の光を集光して、ラインセンサ５０上で光学画像を結像するように、焦点が調節されている。ハイブリッドセンサ１では、このように光学画像用に焦点調節された状態で、同じラインセンサ５０上に磁気画像を結像することができるように、紙葉類１００表面からレンズユニット４０に至る光学画像用の光の光路長と、磁気光学素子７０からレンズユニット４０に至る磁気画像用の光の光路長とが略同一となるように設定されている。このため、単一のレンズユニット４０及び単一のラインセンサ５０を利用して、焦点の合った状態で光学画像と磁気画像の両方を取得することができる。 Both the light for optical image and the light for magnetic image are condensed on the line sensor 50 by the lens unit 40. In the lens unit 40, the focus is adjusted so that the optical image light reflected from the surface of the paper sheet 100 is collected and an optical image is formed on the line sensor 50. In the hybrid sensor 1, an optical image from the surface of the paper sheet 100 to the lens unit 40 is formed so that a magnetic image can be formed on the same line sensor 50 with the focus adjusted for the optical image. The optical path length of the light for the magnetic image and the optical path length of the light for the magnetic image from the magneto-optical element 70 to the lens unit 40 are set to be substantially the same. For this reason, both the optical image and the magnetic image can be acquired in a focused state by using the single lens unit 40 and the single line sensor 50.
　ただし、光学画像を撮像するための光路長と磁気画像を撮像するための光路長とが完全に同一である必要はなく、被写界深度の範囲内での差は許容される。すなわち、ラインセンサ５０で結像される光学画像及び磁気画像の画像品質を維持できる範囲内で略同一であればよい。 However, the optical path length for capturing an optical image and the optical path length for capturing a magnetic image need not be completely the same, and a difference within the depth of field is allowed. That is, the optical image and the magnetic image formed by the line sensor 50 may be substantially the same as long as the image quality can be maintained.
　具体的には、図１に示すように、ハイブリッドセンサ１と下方を通過する紙葉類１００との間の距離Ｈｄによって生ずる光学画像用の光と磁気画像用の光の光路長の差が、レンズユニット４０による被写界深度で吸収される程度の大きさであれば、透明部材８０からレンズユニット４０に至る光路長Ｌｏと磁気光学素子７０からレンズユニット４０に至る光路長Ｌｍとが略同一であればよい。 Specifically, as shown in FIG. 1, the difference between the optical path lengths of the optical image light and the magnetic image light caused by the distance Hd between the hybrid sensor 1 and the paper sheet 100 passing below is as follows. The optical path length Lo from the transparent member 80 to the lens unit 40 and the optical path length Lm from the magneto-optical element 70 to the lens unit 40 are substantially the same as long as it is absorbed by the depth of field by the lens unit 40. If it is.
　また、ハイブリッドセンサ１では、ハイブリッドセンサ５０の下方を紙葉類１００が１回通過する間に、光学画像及び磁気画像の両方の画像を、別々に取得することができる。ハイブリッドセンサ１では、透明部材８０が配置された位置を光学画像取得位置として、この位置を通過する紙葉類１００の光学画像を取得する。また、磁気光学素子７０が配置された位置を磁気画像取得位置として、この位置を通過する紙葉類１００の磁気画像を取得する。このとき、光学画像及び磁気画像を別々に取得するため、光学画像用光源Ｓ１（１１）と磁気画像用光源Ｓ２（１２）の発光タイミングを制御する。 Further, in the hybrid sensor 1, both the optical image and the magnetic image can be acquired separately while the paper sheet 100 passes once below the hybrid sensor 50. In the hybrid sensor 1, an optical image of the paper sheet 100 passing through this position is acquired with the position where the transparent member 80 is disposed as an optical image acquisition position. Further, the magnetic image of the paper sheet 100 passing through this position is acquired with the position where the magneto-optical element 70 is disposed as the magnetic image acquisition position. At this time, in order to acquire an optical image and a magnetic image separately, the light emission timings of the optical image light source S1 (11) and the magnetic image light source S2 (12) are controlled.
　具体的には、光学画像用光源Ｓ１（１１）を点灯してラインセンサ５０により光学画像を形成する１ライン分のデータを取得する処理と、磁気画像用光源Ｓ２（１２）を点灯してラインセンサ５０により磁気画像を形成する１ライン分のデータを取得する処理とを、異なるタイミングで実行する。すなわち、光学画像取得時には光学画像用光源Ｓ１（１１）のみを点灯して、磁気画像取得時には磁気画像用光源Ｓ１２（１２）のみを点灯して、画像を取得する。これにより、紙葉類１００が、ハイブリッドセンサ１を通過したときには、光学画像用光源Ｓ１（１１）をパルス点灯して得られた複数のラインデータにより光学画像を取得して、磁気画像用光源Ｓ２（１２）をパルス点灯して得られた複数のラインデータにより磁気画像を取得することができる。 Specifically, a process for acquiring data for one line for forming an optical image by the line sensor 50 by turning on the optical image light source S1 (11) and a line by turning on the magnetic image light source S2 (12). A process of acquiring data for one line for forming a magnetic image by the sensor 50 is executed at different timings. That is, only the optical image light source S1 (11) is lit when acquiring an optical image, and only the magnetic image light source S12 (12) is lit when acquiring a magnetic image to acquire an image. Thereby, when the paper sheet 100 passes through the hybrid sensor 1, an optical image is obtained from a plurality of line data obtained by pulse-lighting the optical image light source S1 (11), and the magnetic image light source S2 is obtained. A magnetic image can be acquired from a plurality of line data obtained by pulse-lighting (12).
　このように、ハイブリッドセンサ１では、光学画像を取得するための光路長と磁気画像を取得するための光路長とを略同一として、かつ、光学画像用光源Ｓ１（１１）及び磁気画像用光源Ｓ２（１２）の発光タイミングを制御することにより、単一のレンズユニット４０及び単一のラインセンサ５０を利用して、光学画像と磁気画像の両方を、別々に取得することができる。各光源の発光タイミングを制御することによって、各画像を取得するために光が互いに影響することがないので、各光源の波長を変える必要がない。このため、各光源に利用する光として、任意の波長の光を選択することができる。 Thus, in the hybrid sensor 1, the optical path length for acquiring the optical image and the optical path length for acquiring the magnetic image are substantially the same, and the optical image light source S1 (11) and the magnetic image light source S2 are used. By controlling the light emission timing of (12), both the optical image and the magnetic image can be acquired separately using the single lens unit 40 and the single line sensor 50. By controlling the light emission timing of each light source, the light does not affect each other in order to acquire each image, so there is no need to change the wavelength of each light source. For this reason, light of an arbitrary wavelength can be selected as light used for each light source.
　また、レンズユニット４０及びラインセンサ５０を各々１つだけとすることにより、ハイブリッドセンサ１を小型のセンサとすることができる。また、ハイブリッドセンサ１を低コストで製造することができる。 Further, by using only one lens unit 40 and one line sensor 50, the hybrid sensor 1 can be a small sensor. Moreover, the hybrid sensor 1 can be manufactured at low cost.
　また、光学画像及び磁気画像が異なる位置で取得されるので、従来技術のようにダイクロイックミラーを利用する必要がない。また、磁気光学素子７０で光を反射するための反射膜７１には、光の反射性能のみが求められる。そして、反射膜７１を保護する保護膜を形成する場合でも、保護膜には保護性能のみが求められ、従来技術のように透明性を要求されることがない。このため、ハイブリッドセンサ１を小型かつ安価なものとすることができる。 Also, since the optical image and the magnetic image are acquired at different positions, there is no need to use a dichroic mirror as in the prior art. Further, only the light reflection performance is required for the reflection film 71 for reflecting light by the magneto-optical element 70. And even when forming the protective film which protects the reflective film 71, only protective performance is calculated | required by the protective film, and transparency is not requested | required like a prior art. For this reason, the hybrid sensor 1 can be made small and inexpensive.
　次に、図１に示す構成を有するハイブリッドセンサ１の具体的な構造について説明する。図２は、ハイブリッドセンサ１の構成を示す断面模式図である。ラインセンサ５０を中央として、ここから左側が光学画像を取得するための構成であり、右側が磁気画像を取得するための構成となっている。 Next, a specific structure of the hybrid sensor 1 having the configuration shown in FIG. 1 will be described. FIG. 2 is a schematic cross-sectional view showing the configuration of the hybrid sensor 1. With the line sensor 50 at the center, the left side is a configuration for acquiring an optical image, and the right side is a configuration for acquiring a magnetic image.
　ハイブリッドセンサ１は、光学画像を取得するための構成として、光学画像用光源１１と、紙葉類１００から反射された反射光の方向を変えるためのミラーである第１反射板６１及び第２反射板６２と、第２反射板６２で反射された光を透過させる第１ビームスプリッタ３１と、レンズユニット４０と、ラインセンサ５０とを有している。 As a configuration for acquiring an optical image, the hybrid sensor 1 has an optical image light source 11 and a first reflection plate 61 and a second reflection that are mirrors for changing the direction of reflected light reflected from the paper sheet 100. A plate 62, a first beam splitter 31 that transmits light reflected by the second reflecting plate 62, a lens unit 40, and a line sensor 50 are included.
　また、磁気画像を取得するための構成として、磁気画像用光源１２と、磁気画像用光源１２からの光を直線偏光にして出射するための第１偏光板２１と、第１偏光板２１から出射した光を透過する第２ビームスプリッタ３２と、紙葉類１００の磁気特性に応じて第２ビームスプリッタ３２を透過した光の偏光方向を変化させるための磁気光学素子７０と、磁気光学素子７０にバイアス磁界を印加するための磁石ユニット９０と、磁気光学素子７０から出射してラインセンサ５０に到達する光の偏光方向を制限するための第２偏光板２２とを有している。なお、第２ビームスプリッタ３２で反射されてから、第２偏光板２２に至るまでの光路では、光学画像を取得するための第１ビームスプリッタ３１及びレンズユニット４０が利用される。 Further, as a configuration for acquiring a magnetic image, the magnetic image light source 12, a first polarizing plate 21 for emitting light from the magnetic image light source 12 as linearly polarized light, and emission from the first polarizing plate 21. The second beam splitter 32 that transmits the transmitted light, the magneto-optical element 70 for changing the polarization direction of the light transmitted through the second beam splitter 32 according to the magnetic characteristics of the paper sheet 100, and the magneto-optical element 70 A magnet unit 90 for applying a bias magnetic field and a second polarizing plate 22 for limiting the polarization direction of the light emitted from the magneto-optical element 70 and reaching the line sensor 50 are provided. Note that the first beam splitter 31 and the lens unit 40 for obtaining an optical image are used in the optical path from the light reflected by the second beam splitter 32 to the second polarizing plate 22.
　磁気光学素子７０の下面側には、光学画像取得位置Ｐｏを含まずかつ磁気画像取得位置Ｐｍを含む所定領域に反射膜７１が形成され、この反射膜７１を保護するために保護膜７２が形成されている。 On the lower surface side of the magneto-optical element 70, a reflective film 71 is formed in a predetermined region that does not include the optical image acquisition position Po and includes the magnetic image acquisition position Pm, and a protective film 72 is formed to protect the reflective film 71. Has been.
　第１ビームスプリッタ３１は、第２反射板６２から入射する光を透過してレンズユニット４０へ導く機能と、第２ビームスプリッタ３２から入射する光を反射してレンズユニット４０へ導く機能とを有する。また、第２ビームスプリッタ３２は、第１偏光板２１から入射する光を透過して磁気光学素子７０へ導く機能と、磁気光学素子７０から入射する光を反射して第１ビームスプリッタ３１へ導く機能とを有する。これにより、光学画像取得位置Ｐｏからの光と、磁気画像取得位置Ｐｍからの光を、共にレンズユニット４０に入射させることができる。 The first beam splitter 31 has a function of transmitting the light incident from the second reflector 62 and guiding it to the lens unit 40, and a function of reflecting the light incident from the second beam splitter 32 and guiding it to the lens unit 40. . The second beam splitter 32 transmits light incident from the first polarizing plate 21 and guides it to the magneto-optical element 70. The second beam splitter 32 reflects light incident from the magneto-optical element 70 and guides it to the first beam splitter 31. With functions. Thereby, both the light from the optical image acquisition position Po and the light from the magnetic image acquisition position Pm can be incident on the lens unit 40.
　また、光学画像取得位置Ｐｏから第１ビームスプリッタ３１へ至る光路長と、磁気画像取得位置Ｐｍから第１ビームスプリッタ３１へ至る光路長とが略同一となるように、第１反射板６１及び第２反射板６２が設置されている。 Further, the first reflector 61 and the first reflector 61 are arranged so that the optical path length from the optical image acquisition position Po to the first beam splitter 31 is substantially the same as the optical path length from the magnetic image acquisition position Pm to the first beam splitter 31. Two reflectors 62 are installed.
　なお、図２では、断面模式図を示しているが、ラインセンサ５０は、ＣＣＤやＣＭＯＳ等の撮像素子をライン状に一列に配置したセンサである。これに対応するように、例えば、光学画像用光源１１及び磁気画像用光源１２としてライン状光源を利用し、レンズユニット４０としてロッドレンズアレイを利用する。また、第１偏光板２１及び第２偏光板２２と、第１ビームスプリッタ３１及び第２ビームスプリッタ３２と、第１反射板６１及び第２反射板６２と、磁石ユニット９０についても、ラインセンサ５０に対応して図２紙面奥行方向に延在する形状を有している。 In addition, in FIG. 2, although the cross-sectional schematic diagram is shown, the line sensor 50 is a sensor which has arrange | positioned imaging elements, such as CCD and CMOS, in the line form. For example, a linear light source is used as the optical image light source 11 and the magnetic image light source 12, and a rod lens array is used as the lens unit 40. The line sensor 50 also applies to the first polarizing plate 21 and the second polarizing plate 22, the first beam splitter 31 and the second beam splitter 32, the first reflecting plate 61 and the second reflecting plate 62, and the magnet unit 90. 2 has a shape extending in the depth direction of FIG.
　光学画像用光源１１としては、例えば、ライン状に配置したＬＥＤ（Ｌｉｇｈｔ　Ｅｍｉｔｔｉｎｇ　Ｄｉｏｄｅ）やＬＤ（Ｌａｓｅｒ　Ｄｉｏｄｅ）を利用する。光の波長は特に限定されず、取得したい光学画像によって決定される。また、磁気画像用光源１２についても、同様に、ＬＥＤやレーザー光を利用するが、その波長も特に限定されない。本実施形態に係るハイブリッドセンサ１では、光源の発光タイミングを制御して光学画像及び磁気画像を取得する。このため、光学画像用光源１１と磁気画像用光源１２とで異なる波長の光を利用する必要がなく、取得したい画像に応じて必要な波長を選択して利用することができる。 As the optical image light source 11, for example, LEDs (Light Emitting Diode) and LD (Laser Diode) arranged in a line shape are used. The wavelength of light is not particularly limited, and is determined by the optical image desired to be acquired. Similarly, the magnetic image light source 12 uses LED or laser light, but the wavelength is not particularly limited. In the hybrid sensor 1 according to the present embodiment, an optical image and a magnetic image are acquired by controlling the light emission timing of the light source. For this reason, it is not necessary to use light of different wavelengths between the optical image light source 11 and the magnetic image light source 12, and a necessary wavelength can be selected and used according to an image to be acquired.
　磁気光学素子７０は、透明なガラス基板やガーネット基板上に磁気光学層である磁性ガーネット膜を形成した部材である。光を透過することができるため、光学画像取得位置Ｐｏを含む所定領域では、この磁気光学素子７０を測定窓としてそのまま利用することができる。 The magneto-optical element 70 is a member in which a magnetic garnet film as a magneto-optical layer is formed on a transparent glass substrate or garnet substrate. Since the light can be transmitted, the magneto-optical element 70 can be used as a measurement window as it is in a predetermined region including the optical image acquisition position Po.
　また、磁気画像取得位置Ｐｍを含む所定領域で、磁気光学素子７０の素子内を透過した光をラインセンサ５０側へ反射させる反射膜７１として、例えば、電子ビーム蒸着法やスパッタリング法によって形成された金属膜が利用される。この反射膜７１による光の反射性能を維持するため、反射膜７１を保護膜７２によって保護している。ただし、反射膜７１が十分な耐久性を有する場合や、反射膜７１に紙葉類１００や異物が接触する可能性がないような場合には、保護膜７２による保護は不要である。 In addition, the reflection film 71 that reflects light transmitted through the magneto-optical element 70 in the predetermined region including the magnetic image acquisition position Pm toward the line sensor 50 is formed by, for example, an electron beam evaporation method or a sputtering method. A metal film is used. In order to maintain the light reflection performance of the reflective film 71, the reflective film 71 is protected by a protective film 72. However, when the reflective film 71 has sufficient durability, or when there is no possibility that the paper sheet 100 or a foreign object comes into contact with the reflective film 71, protection by the protective film 72 is unnecessary.
　このように、ハイブリッドセンサ１では、１枚の磁気光学素子７０の一部では光を透過させて光学画像の取得に利用して、一部では反射膜７１により光を反射させて磁気画像の取得に利用することができる。すなわち、磁気光学素子７０は、磁気画像取得のための機能に加えて、光学画像取得のための測定窓としての機能をも実現している。 As described above, in the hybrid sensor 1, a part of one magneto-optical element 70 transmits light to be used for acquiring an optical image, and a part of the magneto-optical element 70 is used to acquire a magnetic image by reflecting light with the reflection film 71. Can be used. That is, the magneto-optical element 70 realizes a function as a measurement window for acquiring an optical image in addition to a function for acquiring a magnetic image.
　なお、ハイブリッドセンサ１における磁気光学素子７０の利用方法が、図２に示す態様に限定されるものではない。図３は、磁気光学素子７０の他の利用方法を示す断面模式図である。例えば、図３（ａ）に示すように、光学画像を撮像するための測定窓として利用する樹脂やガラス等の透明部材８０を、磁気画像を取得するための磁気光学素子７０とは別に設ける態様であってもよい。また、図３（ｂ）に示すように、ガラス等の透明部材８０を基板として、その一部領域に磁気光学層を成膜して該領域を磁気光学素子７０として利用してもよいし、別途準備した磁気光学素子７０を透明部材８０の基板と貼り合わせて利用する態様であってもよい。また、図３（ｂ）に示すように、保護膜７２を設ける態様の他、同図（ｃ）に示すように、透明部材８０の上面側、すなわち紙葉類１００や異物が接触することがない側に反射膜７１を介して磁気光学素子７０を配置することにより、保護膜７２を省略する態様であっても構わない。 In addition, the utilization method of the magneto-optical element 70 in the hybrid sensor 1 is not limited to the aspect shown in FIG. FIG. 3 is a schematic cross-sectional view showing another method of using the magneto-optical element 70. For example, as shown in FIG. 3A, a mode in which a transparent member 80 such as resin or glass used as a measurement window for capturing an optical image is provided separately from the magneto-optical element 70 for acquiring a magnetic image. It may be. Further, as shown in FIG. 3B, a transparent member 80 such as glass may be used as a substrate, a magneto-optical layer may be formed in a partial region thereof, and the region may be used as the magneto-optical element 70. A mode in which the separately prepared magneto-optical element 70 is used by being bonded to the substrate of the transparent member 80 may be used. Further, as shown in FIG. 3B, in addition to the aspect in which the protective film 72 is provided, as shown in FIG. 3C, the upper surface side of the transparent member 80, that is, the paper sheet 100 and foreign matter may come into contact. It is possible to omit the protective film 72 by disposing the magneto-optical element 70 via the reflective film 71 on the non-side.
　ハイブリッドセンサ１では、光学画像用光源１１及び磁気画像用光源１２の点灯タイミングを制御することにより、ハイブリッドセンサ１の下方を紙葉類１００が１回通過するだけで、光学画像及び磁気画像を別々に取得することができる。このとき行われる光源制御は、例えば、ハイブリッドセンサ１を利用する紙葉類識別装置によって、紙葉類の搬送タイミングに合わせて行われる制御である。 In the hybrid sensor 1, by controlling the lighting timing of the optical image light source 11 and the magnetic image light source 12, the optical image and the magnetic image are separately separated by passing the paper sheet 100 once under the hybrid sensor 1. Can be obtained. The light source control performed at this time is, for example, control performed by the paper sheet identification device using the hybrid sensor 1 in accordance with the conveyance timing of the paper sheet.
　図４は、ハイブリッドセンサ１を利用して紙葉類の種類を識別する紙葉類識別装置１０１の例を示すブロック図である。紙葉類識別装置１０１は、紙葉類１００の搬送に合わせてハイブリッドセンサ１の有する光学画像用光源１１及び磁気画像用光源１２の点灯タイミングを制御する。そして、ラインセンサ５０によって光学画像及び磁気画像を取得して、各画像から抽出される特徴量に基づいて紙葉類１００の種類や真贋を識別する機能を有する。 FIG. 4 is a block diagram illustrating an example of a paper sheet identification device 101 that uses the hybrid sensor 1 to identify the type of paper sheet. The paper sheet identification device 101 controls the lighting timing of the optical image light source 11 and the magnetic image light source 12 of the hybrid sensor 1 in accordance with the conveyance of the paper sheet 100. The line sensor 50 acquires an optical image and a magnetic image, and has a function of identifying the type and authenticity of the paper sheet 100 based on the feature amount extracted from each image.
　紙葉類識別装置１０１は、ハイブリッドセンサ１の下方で紙葉類１００を搬送する紙葉類搬送部２と、制御部３と、記憶部４と、通信インターフェイス５とを有している。制御部３は、光学画像用光源１１及び磁気画像用光源１２を制御する光源制御部３ｄと、紙葉類１００の搬送を制御する搬送制御部３ｅと、ラインセンサ５０から出力される信号のＡ／Ｄ変換等を行う信号処理部３ａと、信号処理部３ａによって得られたデータから画像データを生成する画像生成部３ｂと、画像生成部３ｂによって得られた光学画像及び磁気画像から特徴量を抽出して紙葉類判定用テンプレート４ａと比較することにより紙葉類１００の種類や真贋を判定する紙葉類判定部３ｃとを有している。記憶部４は、紙葉類１００の種類や真贋を判定するために利用する紙葉類判定用テンプレート４ａや、画像生成部３ｂによって生成される光学画像及び磁気画像を含む紙葉類画像４ｂのデータを保存するために利用される。また、記憶部４は、制御部３による各機能及び動作の実現に必要なプログラムやデータ等の保存にも利用される。また、通信インターフェイス５は、紙葉類１００の判定結果を外部装置へ出力したり、外部装置からの指示操作や設定操作を受け付ける機能を有している。なお、紙葉類画像から特徴量を抽出して、この特徴量に基づいて紙葉類１００の種類を識別する機能及び動作については、従来技術を利用することが可能であるため詳細な説明は省略する。 The paper sheet identification apparatus 101 includes a paper sheet transport unit 2 that transports the paper sheet 100 below the hybrid sensor 1, a control unit 3, a storage unit 4, and a communication interface 5. The control unit 3 includes a light source control unit 3 d that controls the optical image light source 11 and the magnetic image light source 12, a conveyance control unit 3 e that controls conveyance of the paper sheet 100, and a signal A output from the line sensor 50. A feature amount is obtained from a signal processing unit 3a that performs D / D conversion, an image generation unit 3b that generates image data from data obtained by the signal processing unit 3a, and an optical image and a magnetic image obtained by the image generation unit 3b. A paper sheet determination unit 3c that determines the type and authenticity of the paper sheet 100 by extracting and comparing with the paper sheet determination template 4a. The storage unit 4 stores a paper sheet determination template 4a used for determining the type and authenticity of the paper sheet 100, and a paper sheet image 4b including an optical image and a magnetic image generated by the image generation unit 3b. Used to store data. The storage unit 4 is also used for storing programs and data necessary for realizing the functions and operations by the control unit 3. Further, the communication interface 5 has a function of outputting the determination result of the paper sheet 100 to an external device and receiving an instruction operation and a setting operation from the external device. The function and operation for extracting the feature amount from the paper sheet image and identifying the type of the paper sheet 100 based on the feature amount can be performed using the conventional technology, so that a detailed description will be given. Omitted.
　次に、紙葉類搬送部２による紙葉類１００の搬送状況に基づいて、光源制御部３ｄによって行われる光学画像用光源１１及び磁気画像用光源１２の点灯制御について説明する。 Next, lighting control of the optical image light source 11 and the magnetic image light source 12 performed by the light source control unit 3d based on the conveyance state of the paper sheet 100 by the paper sheet conveyance unit 2 will be described.
　図５は、光学画像用光源１１及び磁気画像用光源１２の交番点灯制御によって光学画像及び磁気画像を取得する方法を説明する図である。まず、紙葉類１００が、図２に示す光学画像取得位置Ｐｏに到達すると、図５（ａ）に示すように光学画像用光源１１が点灯されてＯＮ状態となる。そして、ラインセンサ５０によって、光学画像を形成する１ライン分のラインデータが取得される。なお、図５では、こうして取得された１ライン目のラインデータを、光学画像ラインデータの「光学１」として示しているが、同図は、光源の点灯とラインデータとの関係を示すものであって、ラインデータの生成タイミングを限定するものではない。 FIG. 5 is a diagram for explaining a method of acquiring an optical image and a magnetic image by alternating lighting control of the optical image light source 11 and the magnetic image light source 12. First, when the paper sheet 100 reaches the optical image acquisition position Po shown in FIG. 2, the optical image light source 11 is turned on and turned on as shown in FIG. The line sensor 50 acquires line data for one line forming an optical image. In FIG. 5, the line data of the first line acquired in this way is shown as “optical 1” of the optical image line data, but this figure shows the relationship between the lighting of the light source and the line data. Thus, the generation timing of the line data is not limited.
　その後、紙葉類１００が、図２に示す磁気画像取得位置Ｐｍに到達するまでの間は、図５（ａ）に示すように、光学画像用光源１１のみを点灯して、１ラインずつ光学画像を形成するラインデータを取得する処理が続けられる。取得されたラインデータにより、図５（ｂ）に示すように、１ラインずつ光学画像が形成されてゆく。なお、光学画像を取得する処理のみを行う間は、ラインセンサ５０のラインデータの取得タイミングに合わせて図５（ａ）に示すように点灯（ＯＮ）及び消灯（ＯＦＦ）を繰り返す態様の他、光学画像用光源１１を点灯したままの状態としても構わない。 Thereafter, until the paper sheet 100 reaches the magnetic image acquisition position Pm shown in FIG. 2, as shown in FIG. The process of acquiring line data for forming an image is continued. Based on the acquired line data, an optical image is formed line by line as shown in FIG. In addition, while performing only the process which acquires an optical image, in addition to the aspect which repeats lighting (ON) and light extinction (OFF) as shown to Fig.5 (a) according to the acquisition timing of the line data of the line sensor 50, The optical image light source 11 may be left on.
　紙葉類１００が、図２に示す搬送方向２００に搬送されて、磁気画像取得位置Ｐｍに到達すると、磁気画像の取得が開始される。具体的には、図５（ａ）に示すように、光学画像を形成するｎライン目のラインデータを取得して光学画像用光源１１が消灯されたタイミングで、紙葉類１００が磁気画像取得位置Ｐｍに到達すると、次に、磁気画像用光源１２を点灯する。そして、ラインセンサ５０によって、磁気画像を形成する１ライン分のラインデータ（図中「磁気１」）を取得する。磁気画像の１ライン分のラインデータを取得し終えると、磁気画像用光源１２を消灯する。これに合わせて、光学画像用光源１１を再び点灯して、光学画像を形成する（ｎ＋１）ライン目のラインデータを取得する処理が開始される。このように、光学画像用光源１１及び磁気画像用光源１２を交互に点灯して、各画像を形成するラインデータを順に取得する処理を行う。この結果、図５（ｂ）に示すように光学画像を形成する１～ｎライン目のラインデータが続けて取得された後、同図（ｃ）に示すように磁気画像を形成する１ライン目のラインデータの取得が開始され、その後は、光学画像ラインデータ及び磁気画像ラインデータを、１ラインずつ交互に取得する処理が繰り返される。 When the paper sheet 100 is conveyed in the conveyance direction 200 shown in FIG. 2 and reaches the magnetic image acquisition position Pm, acquisition of the magnetic image is started. Specifically, as shown in FIG. 5A, the paper sheet 100 acquires the magnetic image at the timing when the optical image light source 11 is turned off by acquiring line data of the nth line forming the optical image. When the position Pm is reached, the magnetic image light source 12 is then turned on. The line sensor 50 acquires line data (“magnetic 1” in the figure) for one line forming a magnetic image. When the line data for one line of the magnetic image has been acquired, the magnetic image light source 12 is turned off. In accordance with this, the light source 11 for optical images is turned on again, and processing for acquiring line data of the (n + 1) th line forming the optical image is started. In this way, the optical image light source 11 and the magnetic image light source 12 are alternately turned on to perform processing for sequentially obtaining line data for forming each image. As a result, after the line data of the 1st to nth lines forming the optical image are continuously acquired as shown in FIG. 5B, the first line forming the magnetic image as shown in FIG. 5C is obtained. Line data acquisition is started, and thereafter, the process of alternately acquiring the optical image line data and the magnetic image line data line by line is repeated.
　こうして、紙葉類１００の全体が、図２に示す光学画像取得位置（Ｐｏを）通過すると、紙葉類１００全面の光学画像を取得する処理が完了する。光学画像を取得する処理が完了すると、その後は、磁気画像を形成する磁気画像ラインデータを取得する処理のみが行われる。そして、紙葉類１００の全体が、図２に示す磁気画像取得位置Ｐｍを通過すると、紙葉類１００全面の磁気画像を取得する処理が完了する。こうして、光学画像取得位置Ｐｏからの光によって光学画像が取得された後、磁気画像取得位置Ｐｍからの光によって磁気画像が取得される。 Thus, when the entire paper sheet 100 passes through the optical image acquisition position (Po) shown in FIG. 2, the process of acquiring the optical image of the entire surface of the paper sheet 100 is completed. When the process of acquiring the optical image is completed, only the process of acquiring the magnetic image line data for forming the magnetic image is performed thereafter. When the entire paper sheet 100 passes the magnetic image acquisition position Pm shown in FIG. 2, the process of acquiring the magnetic image of the entire surface of the paper sheet 100 is completed. Thus, after an optical image is acquired with light from the optical image acquisition position Po, a magnetic image is acquired with light from the magnetic image acquisition position Pm.
　なお、交番点灯制御については、光学画像用光源１１及び磁気画像用光源１２を１回ずつ交互に点灯する方法に限定されるものではない。例えば、図６に示すように、光学画像用光源１１を複数回点灯した後に、磁気画像用光源１２を１回点灯する態様であっても構わない。具体的には、例えば、光学画像用光源１１が紙葉類１００に向けて可視光赤（Ｒ）、緑（Ｇ）及び青（Ｂ）の各光を照射する光源を含む場合には、図６に示すように、各光源を順に点灯して各色のラインデータを取得した後、磁気画像用光源１２を１回点灯することにより、可視光赤、緑及び青の各光学画像と磁気画像とを取得する。また、例えば、可視光、赤外光及び紫外光の各光源を利用する場合には、同様に、各光源を順に点灯して、可視光、赤外光及び紫外光の各光学画像と磁気画像とを取得する。この他、光学画像と磁気画像で要求される画像の解像度が異なる場合にも、要求される解像度に応じて各光源の点灯を制御して、各光源毎に必要な解像度を有する各画像を取得することができる。 The alternating lighting control is not limited to the method of alternately lighting the optical image light source 11 and the magnetic image light source 12 one by one. For example, as shown in FIG. 6, after turning on the optical image light source 11 a plurality of times, the magnetic image light source 12 may be turned on once. Specifically, for example, when the optical image light source 11 includes a light source for irradiating visible light red (R), green (G), and blue (B) toward the paper sheet 100, As shown in FIG. 6, after each light source is turned on in order to acquire line data of each color, the light source for magnetic image 12 is turned on once so that each optical image and magnetic image of visible light red, green, and blue To get. For example, when using each light source of visible light, infrared light, and ultraviolet light, similarly, each light source is turned on in turn, and each optical image and magnetic image of visible light, infrared light, and ultraviolet light are displayed. And get. In addition, even when the required image resolution differs between the optical image and the magnetic image, the lighting of each light source is controlled according to the required resolution to obtain each image having the necessary resolution for each light source. can do.
　また、光学画像について、反射画像を取得する場合を例に説明を行ったが、本実施形態がこれに限定されるものではない。例えば、図７に示すように、搬送される紙葉類１００の下面側に、透過画像を撮像するためのレンズユニット４１及びラインセンサ５１を配置して、反射画像に加えて、ラインセンサ５１により透過画像を取得する態様であってもよい。 In addition, the case where a reflection image is acquired for an optical image has been described as an example, but the present embodiment is not limited to this. For example, as shown in FIG. 7, a lens unit 41 and a line sensor 51 for capturing a transmission image are arranged on the lower surface side of the conveyed paper sheet 100, and in addition to the reflected image, the line sensor 51 A mode in which a transmission image is acquired may be used.
　また、図８に示すように、紙葉類１００の下面側に、透過画像を撮像するための光源１３を配置して、ラインセンサ５０を利用して、紙葉類１００の反射画像に加えて透過画像を取得する態様であっても構わない。この場合には、反射画像用の光学画像用光源１１、透過画像用の光学画像用光源１３及び磁気画像用光源１２の各々の点灯タイミングを制御して交番点灯することにより、紙葉類１００の反射画像及び透過画像と、磁気画像とを取得することができる。 Further, as shown in FIG. 8, a light source 13 for capturing a transmission image is arranged on the lower surface side of the paper sheet 100, and the line sensor 50 is used to add to the reflected image of the paper sheet 100. It is also possible to obtain a transmission image. In this case, by controlling the lighting timing of each of the optical image light source 11 for the reflection image, the optical image light source 13 for the transmission image, and the magnetic image light source 12 to alternately turn on, A reflection image, a transmission image, and a magnetic image can be acquired.
　また、図９に示すように、紙葉類１００の光学画像として、反射画像に代えて透過画像を取得する態様であっても構わない。この場合には、光学画像用光源１１を紙葉類１００の下面側に配置して、この光源と磁気画像用光源１２の交番点灯制御を行うことにより、紙葉類１００の透過画像及び磁気画像を取得することができる。 Further, as shown in FIG. 9, the optical image of the paper sheet 100 may be a mode in which a transmission image is obtained instead of the reflection image. In this case, the optical image light source 11 is arranged on the lower surface side of the paper sheet 100, and the alternating lighting control of the light source and the magnetic image light source 12 is performed, whereby the transmission image and the magnetic image of the paper sheet 100 are controlled. Can be obtained.
　また、図２及び図７～図９では、光学画像取得位置Ｐｏ及び磁気画像取得位置Ｐｍからレンズユニット４０に至る光路上に反射板やビームスプリッタを配置する態様を示したが、本実施形態がこれに限定されるものではない。２つの異なる位置からの光を、光路長を略同一としてかつ単一のラインセンサに導くことができれば、光学系の構成は特に限定されない。例えば、プリズム等、単一の光学ブロックを利用して構成する態様であっても構わない。 2 and FIGS. 7 to 9 show the mode in which the reflector and the beam splitter are arranged on the optical path from the optical image acquisition position Po and the magnetic image acquisition position Pm to the lens unit 40. It is not limited to this. The configuration of the optical system is not particularly limited as long as light from two different positions can be guided to a single line sensor with substantially the same optical path length. For example, a configuration in which a single optical block such as a prism is used may be used.
　上述してきたように、本実施形態に係るハイブリッドセンサ１では、単一のラインセンサ５０を利用して、紙葉類１００の光学画像及び磁気画像の両方を取得することができる。 As described above, in the hybrid sensor 1 according to this embodiment, both the optical image and the magnetic image of the paper sheet 100 can be acquired using the single line sensor 50.
　また、光学画像取得位置Ｐｏからラインセンサ５０へ至る光路長と、磁気画像取得位置Ｐｍからラインセンサ５０へ至る光路長とを略同一とすることにより、単一のレンズユニット４０による焦点調整で、焦点の合った光学画像及び磁気画像を取得することができる。 Further, by making the optical path length from the optical image acquisition position Po to the line sensor 50 substantially the same as the optical path length from the magnetic image acquisition position Pm to the line sensor 50, the focus adjustment by the single lens unit 40, In-focus optical and magnetic images can be acquired.
　また、磁気画像を撮像するための磁気光学素子７０の一部領域を、光学画像を撮像するための測定窓として利用して、ハイブリッドセンサ１を構成する部品点数及び組立工数を削減することができる。 Further, by using a partial region of the magneto-optical element 70 for capturing a magnetic image as a measurement window for capturing an optical image, it is possible to reduce the number of parts and the number of assembling steps constituting the hybrid sensor 1. .
　以上のように、本発明は、光学画像とファラデー効果を利用した磁気画像との両方を取得する低コストかつ小型のセンサを実現するために有用な技術である。 As described above, the present invention is a useful technique for realizing a low-cost and compact sensor that acquires both an optical image and a magnetic image using the Faraday effect.
１　光磁気ハイブリッドイメージセンサ
２　紙葉類搬送部
３　制御部
３ａ　信号処理部
３ｂ　画像生成部
３ｃ　紙葉類判定部
３ｄ　光源制御部
３ｅ　搬送制御部
４　記憶部
４ａ　紙葉類判定用テンプレート
４ｂ　紙葉類画像
５　通信インターフェイス
１１、１３　光学画像用光源
１２　磁気画像用光源
２１　第１偏光板
２２　第２偏光板
３１　第１ビームスプリッタ
３２　第２ビームスプリッタ
４０、４１　レンズユニット
５０、５１　ラインセンサ
６１　第１反射板
６２　第２反射板
７０　磁気光学素子
７１　反射膜
７２　保護膜
８０　透明部材
９０　磁石ユニット
１００　紙葉類
１０１　紙葉類識別装置 DESCRIPTION OF SYMBOLS 1 Magneto-optical hybrid image sensor 2 Paper sheet conveyance part 3 Control part 3a Signal processing part 3b Image generation part 3c Paper sheet determination part 3d Light source control part 3e Conveyance control part 4 Memory | storage part 4a Paper sheet determination template 4b Paper sheet Similar image 5 Communication interface 11, 13 Optical image light source 12 Magnetic image light source 21 First polarizing plate 22 Second polarizing plate 31 First beam splitter 32 Second beam splitter 40, 41 Lens unit 50, 51 Line sensor 61 First Reflector 62 Second reflector 70 Magneto-optical element 71 Reflective film 72 Protective film 80 Transparent member 90 Magnet unit 100 Paper sheet 101 Paper sheet identification device

Claims (6)

  1. 　磁気画像取得位置に配置されて、入射した光の偏光状態を紙葉類の磁気特性に応じて変化させて出射する磁気光学素子と、
    　前記磁気画像取得位置で前記磁気光学素子から出射する光と、前記磁気画像取得位置とは異なる光学画像取得位置で前記紙葉類によって反射される光とを、同一位置に集光する光学系と、
    　前記光学系によって光が集光される位置に配置されて、前記光学画像取得位置を通過する前記紙葉類の光学画像を取得すると共に前記磁気画像取得位置を通過する前記紙葉類の磁気画像を取得するラインセンサと
    を備えることを特徴とする光磁気ハイブリッドイメージセンサ。     A magneto-optical element that is arranged at a magnetic image acquisition position and changes the polarization state of incident light according to the magnetic properties of the paper sheet,
    An optical system for condensing light emitted from the magneto-optical element at the magnetic image acquisition position and light reflected by the paper sheets at an optical image acquisition position different from the magnetic image acquisition position at the same position; ,
    A magnetic image of the paper sheet that is disposed at a position where light is collected by the optical system, acquires an optical image of the paper sheet that passes through the optical image acquisition position, and passes through the magnetic image acquisition position. A magneto-optical hybrid image sensor comprising:
  2. 　前記光学系では、前記磁気画像取得位置から前記ラインセンサに至る光の光路長と、前記光学画像取得位置から前記ラインセンサに至る光の光路長とが略同一であることを特徴とする請求項１に記載の光磁気ハイブリッドイメージセンサ。 The optical path length of light from the magnetic image acquisition position to the line sensor and the optical path length of light from the optical image acquisition position to the line sensor are substantially the same in the optical system. The magneto-optical hybrid image sensor according to 1.
  3. 　光学画像を取得するための光学画像用光源と、
    　磁気画像を取得するための磁気画像用光源と
    をさらに備え、
    　前記光学系は、
    　前記光学画像用光源から前記ラインセンサへ至る光路上に
    　前記光学画像用光源から出射して前記紙葉類で反射された光の光路を折り曲げる２つの反射板と、
    　前記反射板から入射する光を透過させる第１ビームスプリッタと、
    　前記第１ビームスプリッタを透過した光を集光して前記ラインセンサに結像するレンズユニットと
    を有し、
    　前記磁気画像用光源から前記ラインセンサへ至る光路上に
    　前記磁気画像用光源から前記磁気光学素子へ入射する光を直線偏光として出射するための第１偏光板と、
    　前記第１偏光板から入射する光を透過させて前記磁気光学素子へ向けて出射すると共に前記磁気光学素子内を透過した後に出射した光を反射する第２ビームスプリッタと、
    　前記第２ビームスプリッタ及び前記第１ビームスプリッタで反射されて前記レンズユニットで集光され前記ラインセンサに至る光として、前記第１偏光板から出射した直線偏光とは異なる偏光方向を有する偏光波を通過させるための第２偏光板と
    を有する
    ことを特徴とする請求項１又は２に記載の光磁気ハイブリッドイメージセンサ。     An optical image light source for obtaining an optical image;
    A magnetic image light source for acquiring a magnetic image;
    The optical system is
    Two reflectors for bending the optical path of the light emitted from the optical image light source and reflected by the paper on the optical path from the optical image light source to the line sensor;
    A first beam splitter that transmits light incident from the reflector;
    A lens unit for condensing the light transmitted through the first beam splitter and forming an image on the line sensor;
    A first polarizing plate for emitting light incident on the magneto-optic element from the magnetic image light source as linearly polarized light on an optical path from the magnetic image light source to the line sensor;
    A second beam splitter that transmits light incident from the first polarizing plate and emits the light toward the magneto-optical element and reflects the light emitted after passing through the magneto-optical element;
    A polarized wave having a polarization direction different from the linearly polarized light emitted from the first polarizing plate is reflected by the second beam splitter and the first beam splitter, is collected by the lens unit, and reaches the line sensor. The magneto-optical hybrid image sensor according to claim 1, further comprising a second polarizing plate for allowing the light to pass therethrough.
  4. 　前記磁気光学素子は、該素子内へ入射した光を前記光学系へ向けて反射することを特徴とする請求項１、２又は３に記載の光磁気ハイブリッドイメージセンサ。 The magneto-optical hybrid image sensor according to claim 1, 2 or 3, wherein the magneto-optical element reflects light incident into the element toward the optical system.
  5. 　前記磁気光学素子は、前記磁気画像取得位置及び前記光学画像取得位置を含む領域に設けられ、前記磁気画像取得位置を含みかつ前記光学画像取得位置を含まない領域に、素子内へ入射した光を前記光学系へ向けて反射する反射膜を有することを特徴とする請求項４に記載の光磁気ハイブリッドイメージセンサ。 The magneto-optical element is provided in an area including the magnetic image acquisition position and the optical image acquisition position, and the light that has entered the element is input to an area that includes the magnetic image acquisition position and does not include the optical image acquisition position. The magneto-optical hybrid image sensor according to claim 4, further comprising a reflective film that reflects toward the optical system.
  6. 　前記光学画像を形成するラインデータを取得する間は前記光学画像用光源を点灯すると共に前記磁気画像用光源を消灯して、前記磁気画像を形成するラインデータを取得する間は前記磁気画像用光源を点灯すると共に前記光学画像用光源を消灯することにより、前記光学画像及び前記磁気画像を取得することを特徴とする請求項３～５のいずれか１項に記載の光磁気ハイブリッドイメージセンサ。 While acquiring the line data for forming the optical image, the optical image light source is turned on and the magnetic image light source is turned off to obtain the line data for forming the magnetic image. 6. The magneto-optical hybrid image sensor according to claim 3, wherein the optical image and the magnetic image are acquired by turning on the light source and turning off the optical image light source.
PCT/JP2013/069109 2012-07-13 2013-07-12 Magneto-optic hybrid image sensor WO2014010719A1 (en)

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EP3018636A1 (en) * 2014-11-06 2016-05-11 Aristotle University Of Thessaloniki-Research Committee Multi signature anti-counterfeiting process and system
WO2019202715A1 (en) * 2018-04-19 2019-10-24 グローリー株式会社 Paper sheet handling device and paper sheet handling method
JPWO2019202715A1 (en) * 2018-04-19 2021-03-11 グローリー株式会社 Paper leaf processing equipment and paper leaf processing method
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