Search

JP-2026075426-A - Paper sheet identification device, paper sheet processing device, paper sheet identification method, and paper sheet identification program

JP2026075426AJP 2026075426 AJP2026075426 AJP 2026075426AJP-2026075426-A

Abstract

[Problem] To provide a paper sheet identification device, a paper sheet processing device, a paper sheet identification method, and a paper sheet identification program that can identify paper sheets with high accuracy based on the amount of fluorescence emission of fluorescent ink printed on the paper sheets. [Solution] A paper sheet identification device comprising: a light source capable of irradiating paper sheets having printed and unprinted portions to be identified with at least a first light and excitation light; a light receiving unit that receives reflected light reflected by the paper sheets from the first light and outputs a reflected light detection signal, and also receives fluorescence emitted from the paper sheets irradiated with the excitation light and outputs a fluorescence detection signal; a calculation unit that calculates a value P by multiplying the density ratio α of the reflected light detection signal of the printed portion and the reflected light detection signal of the unprinted portion by the output value of the fluorescence detection signal of the unprinted portion, and calculates a value F by subtracting the value P from the output value of the fluorescence detection signal of the printed portion; and an identification unit that identifies the paper sheets based on the value F calculated by the calculation unit. [Selection Diagram] Figure 4

Inventors

  • 佐藤 剛

Assignees

  • グローリー株式会社

Dates

Publication Date
20260508
Application Date
20241022

Claims (11)

  1. A light source capable of irradiating paper sheets having printed and unprinted portions to be identified with at least a first light and excitation light, A light receiving unit that receives the reflected light from the paper sheets that the first light has reflected and outputs a reflected light detection signal, and also receives the fluorescence emitted from the paper sheets that have been irradiated with the excitation light and outputs a fluorescence detection signal, A calculation unit calculates a value P obtained by multiplying the density ratio α between the reflected light detection signal of the printed portion and the reflected light detection signal of the non-printed portion by the output value of the fluorescence detection signal of the non-printed portion, and calculates a value F obtained by subtracting the value P from the output value of the fluorescence detection signal of the printed portion. An identification unit that identifies the paper sheets based on the value F calculated by the calculation unit, A paper sheet identification device characterized by being equipped with the following features.
  2. The light receiving unit outputs a color detection signal as the reflected light detection signal. The paper sheet identification device according to claim 1, characterized in that the density ratio α is a color density ratio.
  3. The light receiving unit outputs reflected light detection signals in each of the R, G, and B wavelength bands as the reflected light detection signals. The paper sheet identification device according to claim 2, characterized in that the color density ratio is calculated based on reflected light detection signals in each of the R, G, and B wavelength bands.
  4. The light receiving unit outputs a reflected light detection signal in the infrared region as the reflected light detection signal. The paper sheet identification device according to claim 1 or 3, characterized in that the concentration ratio α is calculated based on the reflected light detection signal in the infrared region.
  5. The paper sheet identification device according to any one of claims 1 to 4, characterized in that the calculation unit calculates the density ratio α from the reflected light detection signal of the printed portion and the reflected light detection signal of the non-printed portion while processing the paper sheets to be identified.
  6. The paper sheet identification device according to any one of claims 1 to 4, characterized in that the concentration ratio α is calculated in advance at a stage before processing the paper sheets to be identified.
  7. The system further includes an image generation unit that generates a reflected light image based on the reflected light detection signal and generates a fluorescent image based on the fluorescent detection signal, The paper sheet identification device according to any one of claims 1 to 6, characterized in that the calculation unit acquires reflected light detection signals of the printed portion and the non-printed portion based on the reflected light image, and acquires fluorescence detection signals of the printed portion and the non-printed portion based on the fluorescence image.
  8. The paper sheet identification device according to any one of claims 1 to 7, characterized in that the light source irradiates at least one of visible light and infrared light as the first light.
  9. A paper sheet processing device characterized by comprising a paper sheet identification device according to any one of claims 1 to 8.
  10. The steps include irradiating a sheet of paper having a printed portion and a non-printed portion to be identified with a first light from a light source, The steps include: receiving the reflected light from the paper sheets that the first light has reflected with a light receiving unit and outputting a reflected light detection signal; The steps include irradiating the aforementioned paper sheets with excitation light from the light source, The steps include: receiving the fluorescence emitted from the paper sheets irradiated with the excitation light with the light receiving unit and outputting a fluorescence detection signal; The steps include calculating a value P obtained by multiplying the output value of the fluorescence detection signal of the non-printed portion by the density ratio α of the density ratio α of the reflected light detection signal of the printed portion and the reflected light detection signal of the non-printed portion, The steps include: calculating a value F obtained by subtracting the value P from the output value of the fluorescence detection signal of the printed portion; A step of identifying the paper sheets based on the value F, A method for identifying paper sheets, characterized by comprising the following features.
  11. A process in which a sheet of paper having a printed area and an unprinted area to be identified is irradiated with a first light from a light source, The process involves receiving the reflected light from the paper sheets that the first light reflects off of the paper sheets with a light receiving unit and outputting a reflected light detection signal. The process involves irradiating the aforementioned paper sheets with excitation light from the aforementioned light source, The process involves receiving the fluorescence emitted from the paper sheets irradiated with the excitation light using the light-receiving unit and outputting a fluorescence detection signal. A process to calculate a value P obtained by multiplying the output value of the fluorescence detection signal of the non-printed portion by the density ratio α of the density ratio α of the reflected light detection signal of the printed portion and the reflected light detection signal of the non-printed portion, A process to calculate a value F obtained by subtracting the value P from the output value of the fluorescence detection signal of the printed portion, A process for identifying the paper sheets based on the aforementioned value F, A paper sheet identification program characterized by causing a paper sheet identification device to execute the following.

Description

This disclosure relates to a paper sheet identification device, a paper sheet processing device, a paper sheet identification method, and a paper sheet identification program. Traditionally, photoluminescent compounds have been known as security elements attached to paper materials such as banknotes. Photoluminescent compounds are excited by ultraviolet light, etc., and produce fluorescence or phosphorescence. Methods for detecting these properties are known, for example, those described in the following literature. Patent Document 1 describes a paper sheet fluorescence detection sensor that simultaneously detects reflected light and transmitted light, and by comparing the results, determines whether fluorescent ink is printed on the front or back of a banknote, or whether the paper itself contains a fluorescent component. Patent Document 2 describes an optical sensor for detecting light from paper sheets printed with at least one of n types of monochromatic inks, comprising: a light source; a light-receiving unit equipped with first to (n-1) light-receiving elements; a storage unit that stores correction values based on reference data obtained by receiving light emitted from the first to n monochromatic inks individually at the light-receiving unit for each type of monochromatic ink; and a correction processing unit that corrects detection data obtained by receiving light emitted from paper sheets irradiated by the light source at the light-receiving unit, using correction values based on the inverse matrix of a normalized matrix A of a predetermined n x n matrix A acquired in advance. Japanese Patent Publication No. 2003-162748Patent No. 7473677 This is a schematic plan view of an example of a genuine banknote, showing its appearance under visible light illumination.This is a schematic plan view of an example of a genuine banknote, showing it when irradiated with excitation light.This is a schematic diagram illustrating an example of the configuration of a paper sheet identification device according to Embodiment 1, and is a view from an oblique direction.This is a schematic cross-sectional view showing the state when the printed and unprinted portions of a banknote are irradiated with the first light and the excitation light, respectively.This is a flowchart illustrating an example of the operation of the paper sheet identification device according to Embodiment 1.This is a schematic diagram illustrating an example of the configuration of a paper sheet identification device according to Embodiment 2, and is a view from an oblique direction.This is a flowchart illustrating an example of the operation of the paper sheet identification device according to Embodiment 2.This is a schematic perspective view showing the external appearance of an example of a paper sheet processing device according to Embodiment 3.This is a schematic cross-sectional diagram illustrating an example of the configuration of the imaging unit of the paper sheet identification device according to Embodiment 3.This is a schematic perspective view illustrating an example of the configuration of the light-receiving unit of the paper sheet identification device according to Embodiment 3.Figure 10 is a schematic diagram showing the wavelength characteristics of the color filter in the light-receiving section.This is a schematic perspective view illustrating another example of the configuration of the light-receiving unit of the paper sheet identification device according to Embodiment 3.Figure 12 is a schematic diagram showing the wavelength characteristics of the color filter in the light-receiving section.This is a block diagram illustrating an example of the configuration of a paper sheet identification device according to Embodiment 3.This diagram schematically shows an example of a reflected light image of a banknote to be identified for authenticity determination using fluorescence measurement.This diagram schematically shows an example of a fluorescence image of a banknote that is to be identified for authenticity determination using fluorescence measurement.This figure shows a reflected light image of the test medium and its color data (B, G, R) in a specific region, and a fluorescent image of the test medium and its color data (B, G, R) in a specific region.Figure 17 shows the results of calculating the color density ratio α using the data shown, and the results of calculating the amount of fluorescence emission P of the background (white paper) of the printed area using the calculated color density ratio α.The results shown in Figure 18 (color density ratio α) were used to calculate the fluorescence emission amount of the fluorescent ink alone, and the results are shown below.The results of calculating the fluorescence emission amount of fluorescent ink alone, without using the color density ratio α, are shown.The following shows the results of calculating the fluorescence emission amount of only the fluorescent ink from the fluo