EP3965079A1

EP3965079A1 - Sheet recognition unit, sheet handling device, and sheet recognition method

Info

Publication number: EP3965079A1
Application number: EP21194570.4A
Authority: EP
Inventors: Masafumi Chikamori; Fumiaki Shimaoka; Akira BOGAKI; Tomoyuki Sengoku
Original assignee: Glory Ltd
Current assignee: Glory Ltd
Priority date: 2020-09-08
Filing date: 2021-09-02
Publication date: 2022-03-09
Also published as: JP2022045035A; JP7496744B2

Abstract

Provided are a sheet recognition unit, a sheet handling device, and a sheet recognition method which can detect a security element having both an optical variable feature and a magnetic feature. The sheet recognition unit is for recognizing a sheet with a security element having an optical variable feature and a magnetic feature. The sheet recognition unit includes: an optical sensor configured to detect optical information of a sheet; a magnetic sensor configured to detect magnetic information of a sheet; and a determination unit configured to determine whether or not an optical variable feature and a magnetic feature are present in the same region of a sheet based on optical information of the sheet detected by the optical sensor and magnetic information of the sheet detected by the magnetic sensor.

Description

TECHNICAL FIELD

The present invention relates to sheet recognition units, sheet handling devices, and sheet recognition methods.

BACKGROUND ART

Optical variable devices (OVDs) have been used as security elements for sheets in many countries. Optical variable devices use an optical element such as a diffraction grating, thin film, or microlens to exhibit an optical variable feature of producing optical effects such as color or pattern changes. Specifically, a change in the angle of light applied to an optical variable device and/or the angle at which the optical variable device is viewed causes an appearance change such as a color or pattern change of the optical variable device. Holograms, optical variable inks (OVIs), and MOTION threads are types of optical variable devices.
Optical variable devices provided with a magnetic feature have appeared as new security elements having both an optical variable feature and a magnetic feature.
For example, WO 2004/023402 discloses a sheet feature detector that includes a light transmissive sensor for measuring a thread part of a sheet and a magnetic sensor for measuring the thread part, and determines that the sheet is a genuine note only when the measurement results from both of these sensors show the existence of a thread.
JP 2017-151654 A discloses a valuable document recognition unit that irradiates an optical variable device region with light rays from two directions, i.e., the first and second directions, receives the light rays reflected on the optical variable device region from the third direction, and determines the presence or absence of the optical variable device region based on the information of these applied light rays.

SUMMARY OF INVENTION

The sheet feature detector disclosed in WO 2004/023402 can detect the magnetic feature of the sheet using the magnetic sensor, but cannot detect the optical variable feature.
The valuable document recognition unit disclosed in JP 2017-151654 A can detect the optical variable feature, but cannot detect the magnetic feature included in the optical variable feature.
In response to the above current state of the art, an object of the present invention is to provide a sheet recognition unit, a sheet handling device, and a sheet recognition method which can detect a security element having both an optical variable feature and a magnetic feature.
In order to solve the above issue and to achieve the object, one aspect of the present invention is a sheet recognition unit for recognizing a sheet with a security element having an optical variable feature and a magnetic feature, the sheet recognition unit including:

an optical sensor configured to detect optical information of a sheet;
a magnetic sensor configured to detect magnetic information of a sheet; and
a determination unit configured to determine whether or not an optical variable feature and a magnetic feature are present in a same region of a sheet based on optical information of the sheet detected by the optical sensor and magnetic information of the sheet detected by the magnetic sensor.

In another aspect of the present invention, the sheet recognition unit further includes an authenticity determination unit configured to determine authenticity of the sheet using a determination result from the determination unit.
In another aspect of the present invention, the authenticity determination unit is configured to determine the sheet as a genuine sheet when the determination unit has determined that the optical variable feature and the magnetic feature are present in the same region.
In another aspect of the present invention, the sheet recognition unit further includes an optical image generation unit and a magnetic image generation unit,

wherein the optical sensor and the magnetic sensor are each a line sensor provided linearly in a width direction of a transport path along which a sheet is transported, the optical sensor defining a first optical line sensor,
the optical image generation unit is configured to generate an optical image based on the optical information detected by the optical sensor,
the magnetic image generation unit is configured to generate a magnetic image based on the magnetic information detected by the magnetic sensor,
and
the determination unit is configured to determine whether or not the optical variable feature is present based on the optical image and whether or not the magnetic feature is present based on the magnetic image.

In another aspect of the present invention, the determination unit is configured to compare a shape of a portion with an optical variable feature in the optical image and a shape of a portion with a magnetic feature in the magnetic image.
In another aspect of the present invention, the optical sensor is configured to detect first reflected light and second reflected light which have been reflected on a sheet,

the second reflected light differs from the first reflected light in at least one of a direction of travel upon incidence on a sheet or a direction of travel after reflection on the sheet,
the optical image generation unit is configured to generate a first reflection image based on optical information of the first reflected light and generate a second reflection image based on optical information of the second reflected light, and
the determination unit is configured to determine whether or not the optical variable feature is present based on the first reflection image and the second reflection image.

In another aspect of the present invention, the sheet recognition unit further includes:

a second optical line sensor that is configured to detect optical information of a sheet transported and is provided linearly in the width direction of the transport path along which a sheet is transported, and
a main determination unit configured to determine a type and orientations of the sheet,
wherein the optical image is a first optical image,
the optical image generation unit is configured to generate a second optical image based on the optical information detected by the second optical line sensor,
the main determination unit is configured to determine a type and orientations of a sheet based at least on the second optical image, and
the determination unit is configured to identify a region of the security element based on a determination result from the main determination unit and determine whether or not the optical variable feature and the magnetic feature are present in the same region within the identified region of the security element.

Another aspect of the present invention is directed to a sheet handling device including the sheet recognition unit.
Another aspect of the present invention is directed to a sheet recognition method for recognizing a sheet with a security element having an optical variable feature and a magnetic feature, the method including:

detecting optical information of a sheet;
detecting magnetic information of a sheet; and
determining whether or not an optical variable feature and a magnetic feature are present in a same region of a sheet based on optical information and magnetic information of the sheet which have been detected.

The sheet recognition unit, the sheet handling device, and the sheet recognition method of the present invention can detect a security element having both an optical variable feature and a magnetic feature.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view of an exemplary banknote to be recognized by a banknote recognition unit of Embodiment 1.
FIG. 2A is a schematic view of an exemplary optical image of the banknote shown in FIG. 1. FIG. 2B is a schematic view of an exemplary magnetic image of the banknote shown in FIG. 1.
FIG. 3A is a perspective view of the appearance of a banknote handling device of Embodiment 1. FIG. 3B is a cross-sectional view of the internal structure of the banknote handling device of Embodiment 1.
FIGs. 4A and 4B are schematic views of the structure of a standard sensor unit in the banknote recognition unit of Embodiment 1. FIG. 4A is a cross-sectional view. FIG. 4B is a plan view.
FIG. 5 is a schematic cross-sectional view of the structure of an optical line sensor in the standard sensor unit of Embodiment 1.
FIG. 6 is a schematic cross-sectional view of the structure of a magnetic line sensor of Embodiment 1.
FIG. 7 is a schematic cross-sectional view of the structure of an optical line sensor (optional sensor unit) of Embodiment 1.
FIG. 8 is a block diagram of the structure of the banknote recognition unit of Embodiment 1.
FIG. 9 is a flowchart of an exemplary procedure of the processing executed by the banknote recognition unit of Embodiment 1.

DESCRIPTION OF EMBODIMENTS

A preferred embodiment of the sheet recognition unit, the sheet handling device, and the sheet recognition method of the present invention is described hereinbelow with reference to the drawings. Various sheets such as banknotes, checks, vouchers, bills, business forms, documents of value, and card-like media are applicable as sheets used in the present invention. Devices and methods for banknotes are used hereinbelow as examples to describe the present invention. The following description is for an exemplary sheet recognition unit, an exemplary sheet handling device, and an exemplary sheet recognition method.

First, the procedure of banknote recognition in Embodiment 1 is summarized with reference to FIGs. 1 and 2. In the present embodiment, a security element having both an optical variable feature and a magnetic feature is detected for authenticity determination.
As shown in FIG. 1, a banknote BN to be recognized in the present embodiment includes a security element S having an optical variable feature OV and a magnetic feature M. The banknote BN has symbols, such as numbers, and patterns, which are formed by the security element S. The security element S has the optical variable feature OV producing optical effects such as color and pattern changes and the magnetic feature M based on the magnetism. In other words, the security element S has both a feature detectable by an optical sensor and a feature detectable by a magnetic sensor. The security element S has the optical variable feature OV and the magnetic feature M in the same region of the banknote BN. Usually, (the planar shape of) the region including the optical variable feature OV and (the planar shape of) the region including the magnetic feature M match each other.
Thus, in the present embodiment, the optical information (suitably, an optical image based on the optical information) of the banknote BN is detected by an optical line sensor, which is an exemplary optical sensor, as shown in FIG. 2A. Also, the magnetic information (suitably, a magnetic image based on the optical information) of the banknote BN is detected by a magnetic line sensor, which is an exemplary magnetic sensor, as shown in FIG. 2B. Based on the detection results from these sensors, whether or not the optical variable feature OV and the magnetic feature M are present in the same region of the banknote BN is determined. Thereby, determination can be made that the security element S is present, i.e., the banknote BN is a genuine note, when the optical variable feature OV and the magnetic feature M are present in the same region of the banknote BN. Also, determination can be made that the security element S is not present, i.e., the banknote BN is a counterfeit note, when the optical variable feature OV and the magnetic feature M are not present in the same region of the banknote BN.
A suitable optical variable feature OV of the security element S is a feature producing an optical effect to cause a color change. In other words, a suitable security element S is one having the same optical variable feature as optical variable devices such as optical variable inks. In this case, a change in the angle of light applied to the security element S and/or the angle at which the security element S is viewed causes a color change in the security element S. Alternatively, the optical variable feature OV of the security element S may be a feature producing an optical effect to cause color and/or pattern changes, as with holograms and MOTION threads. In this case, a change in the angle of light applied to the security element S and/or the angle at which the security element S is viewed causes a color and/or pattern change in the security element S.
The security element S having the optical variable feature OV and the magnetic feature M is hereinafter also referred to as an "optical variable magnetic element S".

The structure of the banknote handling device of the present embodiment is described with reference to FIGs. 3A and 3B. A banknote handling device 200 of the present embodiment has a structure shown in FIGs. 3A and 3B, for example. The banknote handling device 200 shown in FIGs. 3A and 3B includes a hopper 210 in which a plurality of banknotes can be placed; a feeding unit 211 which feeds out banknotes placed in the hopper 210 one by one; a transport path 212 along which the banknotes fed out from the feeding unit 211 are transported; a banknote recognition unit 100 which executes banknote recognition processing; a stacking unit 213 which stacks banknotes recognized as normal by the banknote recognition unit 100; a rejecting unit 214 which stacks abnormal banknotes failing to satisfy the predetermined conditions; a display 215 which displays the information inputted to the banknote handling device 200 and the processing results, for example; and a transport unit (not shown) which transports banknotes one by one along the transport path 212. The transport unit includes a transport means such as a plurality of rollers and a drive device that drives the transport means, such as a motor. The banknote handling device 200 further includes transmissive or reflective optical sensors at the positions indicated by the triangles in the drawing to detect the transport conditions of the banknotes in the device. The shape and skewed state of the banknote may be presumed based on the detection results from the optical sensors. The banknote recognition unit 100, when incorporated and used in the banknote handling device 200, can successively handle the plurality of banknotes placed in the hopper 210 to sort the banknotes by returning a banknote determined as a counterfeit note, an unfit note, or a suspect note to the rejecting unit 214.
The banknote recognition unit 100 includes a standard sensor unit 100a used in a common recognition processing and an optional sensor unit 100b used to detect a special security element such as an optical variable device.
The banknote recognition unit 100 uses data (information) acquired by the sensors in these units 100a and 100b to execute the recognition processing for banknotes BN. The recognition processing details are not limited. For example, in the case of banknotes, the recognition processing may be various functional processings such as recognition of the denominations, determination of the authenticity and fitness of banknotes, acquisition of the banknote outline information or passage point information, and reading of symbols such as numbers and characters printed on banknotes.

Next, the structure of the banknote recognition unit 100, particularly the standard sensor unit 100a and the optional sensor unit 100b, is described with reference to FIGs. 4 to 7.
First, the structure of the standard sensor unit 100a is described with reference to FIGs. 4A and 4B. As shown in FIGs. 4A and 4B, the standard sensor unit 100a includes an upper unit and a lower unit between which the transport path 212 is sandwiched. Along the transport path 212 are transported banknotes BN in the banknote handling device 200. FIG. 4B corresponds to a plan view from below the upper unit of the standard sensor unit 100a. The standard sensor unit 100a has a structure including side-by-side components along the transport path 212, namely photosensors 11 which detect banknotes BN sequentially transported to the standard sensor unit 100a and generate a banknote detection signal for determination of the timing for the standard sensor unit 100a to start detection of the banknotes BN; an optical line sensor (contact image sensor) 20 which detects the optical information (image data) of each banknote BN transported along the transport path 212; a thickness detection sensor 30 which detects the amount of displacement when the banknote BN passes by one of the rollers opposing each other across the transport path 212, thereby detecting the thickness of the banknote BN; a magnetic line sensor 40 which detects the magnetic information of the banknote BN transported along the transport path 212; and photosensors 12 which detect passage of the banknote BN. The optical line sensors 20, the thickness detection sensor 30, and the magnetic line sensor 40 are each provided linearly in the width direction of the transport path 212 and are sufficiently longer than the width of the transport path 212 so that the entire surface of the banknote BN can be detected. The standard sensor unit 100a also includes a transport system 13 to enable the banknote BN to move within the transport path 212. The transport system 13 is not limited, and may be, for example, a system that uses a drive device such as a motor to drive components such as rollers or a belt(s). In addition, below the magnetic line sensor 40 is provided a bristle roller 14 having a bristle material on its peripheral surface, so that the banknote BN can come into close contact with the magnetism detection surface of the magnetic line sensor 40.
Next, the structure of the optical line sensor 20 is described with reference to FIG. 5. As shown in FIG. 5, the optical line sensor 20 includes an upper unit 20a and a lower unit 20b opposing each other. A space for transportation of banknotes BN is formed between the units 20a and 20b. The space defines a part of the transport path 212 of the banknote handling device.
The upper unit 20a includes two reflection light sources 21a, a condensing lens 22a, and a light receiving unit 23a. Each of the light sources 21a extends linearly in the direction (main scanning direction) perpendicular to the transport direction (sub-scanning direction) of banknotes BN, and irradiates one of the main surfaces (hereinafter, surface A) of each banknote BN with a straight line of light having a predetermined wavelength (non-visible light such as infrared light and visible light such as red, green, blue, or other monochromatic light or white light). The condensing lens 22a condenses light emitted from the light sources 21a and reflected on the banknote BN. The light receiving unit 23a includes a plurality of imaging elements (light receiving elements, not shown) arranged linearly in the main scanning direction and converts the light condensed by the condensing lens 22a to electrical signals. The light receiving unit 23a then amplifies the electrical signals, converts the amplified signals to digital data by A/D conversion, and outputs image signals as the optical information of the banknote BN.
The lower unit 20b includes two reflection light sources 21b, a condensing lens 22b, a light receiving unit 23b, and a transmission light source 24. The light sources 21b, the condensing lens 22b, and the light receiving unit 23b are the same as the light sources 21a, the condensing lens 22a, and the light receiving unit 23a of the upper unit 20a, respectively, and thus description thereof is omitted here. The light sources 21b irradiates the other main surface (hereinafter, surface B) of the banknote BN with light. The light source 24 also irradiates the surface B of the banknote BN with a straight line of light having a predetermined wavelength (non-visible light such as infrared light and visible light such as red, green, blue, or other monochromatic light or white light). The transmission light source 24 is provided on the optical axis of the condensing lens 22a of the upper unit 20a. Part of light emitted from the light source 24 passes through the banknote BN, is condensed by the condensing lens 22a, and is detected by the light receiving unit 23a.
Each of the light sources 21a, 21b, and 24 includes, for example, a linear light guide (not shown) extending in the main scanning direction and a plurality of light emitters (for example, light emitting diodes (LEDs), not shown) provided at each end (or one end) of the light guide.
Each of the units 20a and 20b repeatedly takes images of the banknote BN transported in the transport direction (exposes the imaging elements to light) at certain time intervals to output image signals. Thereby, a reflection image of the surface A of the banknote BN and a transmission image of the banknote BN can be acquired based on the output signals from the upper unit 20a, and a reflection image of the surface B of the banknote BN can be acquired based on the output signals from the lower unit 20b.
Next, the structure of the magnetic line sensor 40 is described with reference to FIG. 6. As shown in FIG. 6, the magnetic line sensor 40 is provided linearly in the width direction of the transport path 212 to face one of the surfaces of the transport path 212. The magnetic line sensor 40 detects the magnetic information such as the above-described optical variable magnetic element S, the magnetic ink printed on a banknote BN, and magnetic threads provided in the banknote BN for the entire surface of the banknote BN.
The magnetic line sensor 40 includes a magnetic head 41. The magnetic head 41 includes a plurality of magnetic sensor units 42 arranged linearly in the main scanning direction, and a magnet 43 that generates a bias magnetic field. The magnetic line sensor 40 outputs magnetic data acquired by each magnetic sensor unit 42. In other words, the magnetic line sensor 40 outputs magnetic signals of the same channel number as the number of the magnetic sensor units 42, or magnetic signals of a channel number that is less than the number of the magnetic sensor units 42. Each magnetic sensor unit 42 includes at least one (preferably two) magnetism detection element. Each magnetism detection element may be, for example, a differential magnetism detection element that outputs a change in magnetic flux density of a magnetic body as a fluctuation in voltage, such as a magnetoresistive element (MR element), a fluxgate element (FG element), or a magneto-impedance element (MI element). An element that outputs the intensity (absolute value) of magnetic flux density of a magnetic body may be a hall element, for example. The type of the magnetoresistive element (MR element) may be an anisotropic magnetoresistive element (AMR element), a giant magnetoresistive element (GMR element), or a tunnel magnetoresistive element (TMR element).
Each magnetic sensor unit 42 may be a difference output type that detects the edge of a magnetic body or a level output type that detects the entire region of a magnetic body. The difference output type, which outputs the difference between two magnetism detection elements, typically has difficulty in detecting gradation. Thus, each magnetic sensor unit 42 is preferably a level output type. The level output type outputs a voltage signal proportional to the intensity of magnetic flux density of a magnetic body, and thus can easily detect gradation.
The magnetic line sensor 40 can detect the magnetism of the banknote BN transmissively, i.e., can detect the magnetism of the face, back, and inside of a banknote simultaneously, and thus can be placed only to face one of the surfaces of the transport path 212.
Next, the structure of the optional sensor unit 100b is described with reference to FIG. 7. The banknote recognition unit 100 includes an optical line sensor 50 that detects the optical information of a banknote BN as an optional sensor unit 100b.
As shown in FIG. 7, the optical line sensor 50 includes an upper unit 50a and a lower unit 50b opposing each other. A space for transportation of banknotes BN is formed between the units 50a and 50b. The space defines a part of the transport path 212 of the banknote handling device. Since the units 50a and 50b have the same structure, the upper unit 50a is mainly described here.
The upper unit 50a detects the first reflected light and the second reflected light which have been reflected on a banknote BN. The second reflected light is different from the first reflected light in at least one of the direction of travel upon incidence on the banknote BN or the direction of travel after reflection on the banknote BN. Thereby, the upper unit 50a can determine whether or not the optical variable feature OV is present in the banknote BN. More specifically, the upper unit 50a detects the first reflected light and the second reflected light which have been reflected on the region presumably including the optical variable magnetic element S. Then, the upper unit 50a can determine that the optical variable feature OV is present in the region when the first reflected light and the second reflected light are different in color (wavelength), while it can determine that the optical variable feature OV is not present in the region when the first reflected light and the second reflected light are the same in color (wavelength).
The upper unit 50a is used to acquire reflection images of the banknote BN, and detects the first reflected light and the second reflected light that are different in direction of travel upon incidence on the banknote BN and that are the same in direction of travel after reflection on the banknote BN.
The upper unit 50a includes two reflection light sources 51 and 52, a condensing lens 53, and a light receiving unit 54. Each of the light sources 51 and 52 extends linearly in the main scanning direction and irradiates the surface A of each banknote BN with a straight line of white light including red, green, and blue light rays. The condensing lens 53 condenses the first reflected light and the second reflected light respectively emitted from the light sources 51 and 52 and reflected on the banknote BN. The light receiving unit 54 includes a plurality of imaging elements (light receiving elements, not shown) arranged linearly in the main scanning direction and converts the first reflected light and the second reflected light condensed by the condensing lens 53 to electrical signals. he light receiving unit 54 then amplifies the electrical signals, converts the amplified signals to digital data by A/D conversion, and outputs image signals as the optical information of the banknote BN.
Each of the light sources 51 and 52 includes, for example, a linear light guide (not shown) extending in the main scanning direction and a plurality of light emitters (for example, light emitting diodes (LEDs), not shown) provided at each end (or one end) of the light guide.
The light sources 51 and 52 are placed to emit light in directions different from each other, specifically the first direction and the second direction, respectively, toward transported banknotes BN. The light receiving unit 54 is placed to receive light reflected on each banknote BN from the third direction. In other words, the first reflected light and the second reflected light are different in the direction of travel from emission from the light sources 51 and 52 to upon incidence on the banknote BN (the first direction and the second direction). Meanwhile, the first reflected light and the second reflected light are the same in the direction of travel after reflection on the banknote BN (third direction).
Here, when the angles formed by the first direction, the second direction, and the third direction with the line D perpendicular to the surface of the banknote BN (transport surface 216 of the banknote BN) are defined as the first angle θ1, the second angle θ2, and the third angle θ3, respectively, the light source 51, the light source 52, and the light receiving unit 54 are placed such that the angles θ1, θ2, and θ3 are different from one another. This causes the appearance such as the color of the optical variable magnetic element S in the first reflection image of the banknote BN produced by the light source 51 to be different from the appearance such as the color of the optical variable magnetic element S in the second reflection image of the banknote BN produced by the light source 52, enabling detection of the optical variable feature OV of the optical variable magnetic element S.
The angle θ1 and the angle θ2 are not limited. Preferably, the angle θ1 is -10° to 20° and the angle θ2 is 40° to 70°. More preferably, the angle θ1 is -5° to 15° and the angle θ2 is 45° to 65°.
The angle θ3 is not limited. Yet, in order to clarify the difference in color between the optical variable magnetic element S in the first reflection image and that in the second reflection image for highly accurate detection of the optical variable magnetic element S, the angle θ3 is preferably 25° or greater and smaller than 90°. The upper limit of the angle θ3 is preferably 65° or smaller, more preferably 60° or smaller, still more preferably 55° or smaller.
Each imaging element includes a color selection filter, specifically a color filter of red (R), green (G), or blue (B) which are three primary colors of light. This provides color information to each pixel to add the color information to the output signals from the upper unit 20a.
The light applied by each of the light sources 51 and 52 is not limited as long as it includes light rays having wavelengths corresponding to the colors of the optical variable magnetic element S. Each of the light sources 51 and 52 may sequentially apply red light, green light, and blue light. In this case, each imaging element may not include a color selection filter.
Each of the units 50a and 50b repeatedly takes images of the banknote BN transported in the transport direction (exposes the imaging elements to light) at certain time intervals to output image signals. Thereby, the first reflection image and the second reflection image of the surface A of the banknote BN can be acquired based on the output signals from the upper unit 20a, and the first reflection image and the second reflection image of the surface B of the banknote BN can be acquired based on the output signals from the lower unit 20b.

Next, the functional blocks of the banknote recognition unit 100 are described with reference to FIG. 8. As shown in FIG. 8, the banknote recognition unit 100 further includes a control unit (arithmetic processor) 60 that controls the components of the banknote recognition unit 100 and a storage unit 70. To the control unit 60 are connected the sensors and the storage unit 70, for example.
The storage unit 70 is defined by a storage device such as a volatile or nonvolatile memory and stores various programs and various data for control of the banknote recognition unit 100. The storage unit 70 also stores templates each used as the basic information in a recognition processing, for respective recognition processings.
The control unit 60 is defined by, for example, software programs used to execute various processings, a CPU used to execute the software programs, and various hardware devices controlled by the CPU. The software programs and data required to run the control unit 60 are stored in the storage unit 70.
The control unit 60 has functions of an optical image generation unit 61, a magnetic image generation unit 62, a main determination unit 63, a determination unit 64, and an authenticity determination unit 65.
The optical image generation unit 61 generates first optical images based on the optical information detected by the optical line sensor 50 for optical variable feature detection.
More specifically, the optical image generation unit 61 generates, as the first optical images, a first reflection image based on the optical information (image signals) of the first reflected light reflected on the banknote BN, and generates a second reflection image based on the optical information (image signals) of the second reflected light reflected on the banknote BN. The optical image generation unit 61 generates the first reflection image and the second reflection image of the surface A of the banknote BN from the output signals from the upper unit 50a of the optical line sensor 50, and generates the first reflection image and the second reflection image of the surface B of the banknote BN from the output signals from the lower unit 50b of the optical line sensor 50.
The resolution of each first optical image (each reflection image) generated by the optical line sensor 50 is not limited, and is 10 to 200 dpi, for example, in each of the main scanning direction and the sub-scanning direction.
The optical image generation unit 61 generates second optical images based on the optical information (image signals) detected by the optical line sensor 20 of the standard sensor unit 100a. More specifically, the optical image generation unit 61 generates, as the second optical images, a reflection image of the surface A of the banknote BN and a transmission image of the banknote BN from the output signals from the upper unit 20a of the optical line sensor 20, and generates a reflection image of the surface B of the banknote BN from the output signals from the lower unit 20b of the optical line sensor 20.
The magnetic image generation unit 62 generates a magnetic image based on the magnetic information (magnetic signals) detected by the magnetic line sensor 40. For example, when the magnetic line sensor 40 includes level output type magnetic sensor units 42, the magnetic image generation unit 62 generates gradation data by quantizing the output signals of each channel between the maximum value and the minimum value.
The resolution of the magnetic image from the magnetic line sensor 40 is not limited, and is 10 to 200 dpi, for example, in each of the main scanning direction and the sub-scanning direction.
The main determination unit 63 determines the denomination (type) and orientations of a banknote BN. More specifically, the main determination unit 63 determines the denomination and orientations of the banknote BN based on at least the second optical images. For example, the main determination unit 63 compares the characteristic pattern of the second optical images (the reflection images of the surface A and surface B of the banknote BN and the transmission image of the banknote BN) to the main determination templates which are the characteristic patterns of the denominations and orientations of banknotes BN, and thereby determines the denomination and orientations of the banknote BN in question.
Here, the "orientations" specifically mean four orientations including the orientations of the banknote BN (the upright/inverted orientation of the architecture and/or the portrait on the banknote BN) and the face/back of the banknote BN. In other words, the main determination unit 63 determines whether the architecture and/or the portrait on the banknote BN is upright or inverted and whether the banknote BN is faced up or faced down.
The determination unit 64 determines whether or not the optical variable feature OV and the magnetic feature M are present in the same region on the banknote BN based on the optical information of the banknote BN detected by the optical line sensor 50 for optical variable feature detection and the magnetic information of the banknote BN detected by the magnetic line sensor 40. Thereby, the optical variable magnetic element S can be detected. This is because the optical variable magnetic element S has the optical variable feature OV and the magnetic feature M in the same region on the banknote BN as described above.
Specifically, the determination unit 64 determines that the optical variable feature OV and the magnetic feature M are present in the same region on the banknote BN when at least part of the region of the optical variable feature OV detected based on the optical information of the banknote BN and at least part of the region of the magnetic feature M detected based on the magnetic information of the banknote BN overlap each other. The determination unit 64 determines that the optical variable feature OV and the magnetic feature M are not present in the same region on the banknote BN when these regions do not overlap each other (including when at least one of the optical variable feature OV or the magnetic feature M is not detected).
At this time, preferably, the determination unit 64 identifies the region R (see FIGs. 1 and 2) of the optical variable magnetic element S based on the determination results from the main determination unit 63 and determines whether or not the optical variable feature OV and the magnetic feature M are present in the same region within the identified region R of the optical variable magnetic element S. Thereby, the determination unit 64 can more reliably determine the presence or absence of the optical variable magnetic element S.
More specifically, the identification information on the region R (for example, quadrilateral region) where the optical variable magnetic element S is present is included in advance in the main determination templates for the denominations and orientations of banknotes BN. The determination unit 64 identifies the region R of the optical variable magnetic element S based on the information corresponding to the denomination and the orientations determined by the main determination unit 63. Also, the determination unit 64 determines whether or not the optical variable feature OV is present in the identified region R of the optical variable magnetic element S based on the first optical images. When the optical variable feature OV is present, the determination unit 64 determines whether or not the magnetic feature M is present in the region where the optical variable feature OV is present, based on the magnetic image. When the magnetic feature M is present, the determination unit 64 determines that the optical variable feature OV and the magnetic feature M are present in the same region on the banknote BN. In contrast, in these determination processings, when the determination unit 64 has determined that the optical variable feature OV is not present in the region R or when the determination unit 64 had determined that the magnetic feature M is not present in the region where the optical variable feature OV is present, the determination unit 64 determines that the optical variable feature OV and the magnetic feature M are not present in the same region on the banknote BN.
The determination unit 64 may first determine the presence or absence of the magnetic feature M in the region R of the optical variable magnetic element S, and then determine the presence or absence of the optical variable magnetic element S in the region where the magnetic feature M is present.
Also, the determination unit 64 determines whether or not the optical variable feature OV is present based on the first optical images, and determines whether or not the magnetic feature M is present based on the magnetic image.
As for the optical variable feature OV, the determination unit 64 determines whether or not the optical variable feature OV is present based on the first reflection images and the second reflection images. In other words, the determination unit 64 determines whether or not the optical variable feature OV is present on the surface A of the banknote BN from the first reflection image and the second reflection image of the surface A of the banknote BN, and determines whether or not the optical variable feature OV is present on the surface B of the banknote BN from the first reflection image and the second reflection image of the surface B of the banknote BN. The determination unit 64 may determine whether or not the optical variable feature OV is present only for either the surface A or the surface B of the banknote BN.
For example, the determination unit 64 determines that the optical variable feature OV is present in the region R when the colors (wavelengths) of the first reflection image and the second reflection image, such as the intensity ratios of RGB, are different in the region R of the optical variable magnetic element S. The determination unit 64 determines that the optical variable feature OV is not present in the region R when the colors (wavelengths) of the first reflection image and the second reflection image, such as the intensity ratios of RGB, are the same in the region R of the optical variable magnetic element S.
The determination unit 64 may compare the shape (planar shape) of the optical variable feature portion in at least one of first optical images with the shape (planar shape) of the magnetic feature portion in the magnetic image. This enables highly accurate detection of the optical variable magnetic element S in which the region with the optical variable feature OV matches the region with the magnetic feature M. At this time, the determination unit 64 determines that the optical variable feature OV and the magnetic feature M are present in the same region on the banknote BN when the comparison results show that the shape of the optical variable feature portion and the shape of the magnetic feature portion match each other. Meanwhile, the determination unit 64 determines that the optical variable feature OV and the magnetic feature M are not present in the same region on the banknote BN when the results show that the shapes do not match each other.
When the shape of the optical variable feature portion and the shape of the magnetic feature portion are compared, the resolution of each first optical image (each reflection image) from the optical line sensor 50 and the resolution of the magnetic image from the magnetic line sensor 40 can each be set as appropriate. For example, each resolution may be 10 to 200 dpi in each of the main scanning direction and the sub-scanning direction as described above.
The criteria as the borderline between when the shape of the optical variable feature portion and the shape of the magnetic feature portion match each other and when they do not match each other may be set as appropriate depending on the resolutions of the first optical images and the magnetic image, for example.
The authenticity determination unit 65 determines the authenticity of the banknote BN using the determination result from the determination unit 64. This enables highly accurate determination of the authenticity of the banknote BN based on the presence or absence of the optical variable magnetic element S.
More specifically, the authenticity determination unit 65 determines that the banknote BN is a genuine banknote when the determination unit 64 has determined that the optical variable feature OV and the magnetic feature M are present in the same region on the banknote BN. In contrast, the authenticity determination unit 65 determines that the banknote BN is a counterfeit banknote when the determination unit 64 has determined that the optical variable feature OV and the magnetic feature M are not present in the same region on the banknote BN.

Next, the procedure of the processing executed by the banknote recognition unit 100 is described.
As shown in FIG. 9, first, the optical line sensors 20 and 50 detect the optical information of the banknote BN (step S11).
Next, the magnetic line sensor 40 detects the magnetic information of the banknote BN (step S12).
The optical image generation unit 61 then generates the first optical images and the second optical images based on the optical information (image signals) detected by each of the optical line sensors 20 and 50 (step S11) (step S13).
Next, the magnetic image generation unit 62 generates a magnetic image based on the magnetic information (magnetic signals) detected by the magnetic line sensor 40 (step S12) (step S14).
The order of steps S11 to S14 is not limited except that step S11 is followed by step S13 and that step S12 is followed by step S14, and the order may be changed as appropriate. Also in step S11 and step S13, the order of the optical information detection and the optical image generation for one of the optical line sensors 20 and 50 and those for the other is not limited.
Next, the main determination unit 63 determines the denomination and orientations of the banknote BN based on at least the second optical images generated in step S11 (step S15).
Next, the determination unit 64 identifies the region R of the optical variable magnetic element S based on the determination results in step S15 (step S16).
The determination unit 64 then determines whether or not the optical variable feature OV and the magnetic feature M are present in the same region on the banknote BN based on the optical information of the banknote BN detected by the optical line sensor 50 in step S11 (specifically, the first optical images generated in step S13) and the magnetic information of the banknote BN detected by the magnetic line sensor 40 in step S12 (specifically, the magnetic image generated in step S14) (step S17).
More specifically, for example, first, the determination unit 64 determines whether or not the optical variable feature OV is present in the region R of the optical variable magnetic element S identified in step S16 based on the first optical images generated in step S13. When the optical variable feature OV is present, subsequently, the determination unit 64 determines whether or not the magnetic feature M is present in the region where the optical variable feature OV is present based on the magnetic image generated in step S14. When the magnetic feature M is present, the determination unit 64 determines that the optical variable feature OV and the magnetic feature M are present in the same region on the banknote BN. In contrast, in these determination steps, when the determination unit 64 has determined that the optical variable feature OV is not present in the region R or that the magnetic feature M is not present in the region where the optical variable feature OV is present, the determination unit 64 determines that the optical variable feature OV and the magnetic feature M are not present in the same region on the banknote BN.
At this time, as described above, the order of determination of the presence or absence of the optical variable feature OV and determination of the presence or absence of the magnetic feature M may be reversed.
The authenticity determination unit 65 then determines the authenticity of the banknote BN using the determination result from the determination unit 64 (step S18). More specifically, the authenticity determination unit 65 determines the banknote BN as a genuine banknote when the determination unit 64 has determined in step S17 that the optical variable feature OV and the magnetic feature M are present in the same region on the banknote BN. The authenticity determination unit 65 determines the banknote BN as a counterfeit banknote when the determination unit 64 has determined in step S17 that the optical variable feature OV and the magnetic feature M are not present in the same region on the banknote BN.
As described above, in the embodiment above, whether or not the optical variable feature OV and the magnetic feature M are present in the same region on the banknote BN is determined based on the optical information of the banknote BN detected by the optical line sensor 50 for optical variable feature detection and the magnetic information of the banknote BN detected by the magnetic line sensor 40. Thus, the security element (optical variable magnetic element) S having both the optical variable feature OV and the magnetic feature M can be detected.
In the embodiment above, the case is described where in the optical line sensor 50 for optical variable feature detection, the first reflected light and the second reflected light which have been reflected on the banknote BN are different in direction of travel upon incidence on the banknote BN while being the same in direction of travel after reflection on the banknote BN. However, the first reflected light and the second reflected light may: (1) be the same in direction of travel upon incidence on the banknote BN while being different in direction of travel after reflection on the banknote BN; or (2) be different in direction of travel upon incidence on the banknote BN and different in direction of travel after reflection on the banknote BN. In the case (1), a light source for emitting light in one direction toward the banknote BN, and first and second light receiving units respectively receiving the first reflected light and the second reflected light may be provided. In the case (2), first and second light sources for respectively emitting light in two different directions toward the banknote BN, and first and second light receiving units respectively receiving the first reflected light and the second reflected light may be provided.
In the embodiment above, the case is described where the optical sensor and the magnetic sensor of the present invention respectively define the optical line sensor 50 and the magnetic line sensor 40 respectively acquiring the optical data (optical characteristics) and the magnetic data (magnetic characteristics) of the banknote BN in the entire region in the width direction of the transport path 212. However, the optical sensor and magnetic sensor of the present invention may define, respectively, a point sensor that acquires the optical data (optical characteristics) of the banknote BN and a point sensor that acquires the magnetic data (magnetic characteristics) of the banknote BN at one point in the width direction of the transport path 212.
In the embodiment above, the banknote BN is subjected to long edge feed along the transport path 212 in the banknote handling device 200. Alternatively, the banknote BN may be subjected to short edge feed along the transport path in the banknote handling device of the present invention.
In the embodiment above, the sheet recognition unit of the present invention is mounted in the banknote handling device 200 which recognizes banknotes BN and stacks them according to the denominations (for example, banknote depositing machine, banknote dispensing machine, banknote depositing/dispensing machine). The sheet recognition unit of the present invention, however, may be applied to devices other than banknote handling devices, such as a print inspection device used in printing of banknotes. In this case, the sheet recognition unit enables inspection of whether or not an optical variable magnetic element is appropriately printed on banknotes.
An embodiment of the present invention has been described above with reference to the drawings. The present invention is not limited to the embodiment. Also, the structures of the embodiment may be combined or modified as appropriate within the range not departing from the gist of the present invention.

INDUSTRIAL APPLICABILITY

As described above, the present invention provides a technique useful in detecting a security element having both an optical variable feature and a magnetic feature on a sheet.

REFERENCE SIGNS LIST

11, 12:: photosensor
13:: transport system
14:: bristle roller
20:: optical line sensor
20a:: upper unit
20b:: lower unit
21a, 21b:: reflection light source
22a, 22b:: condensing lens
23a, 23b:: light receiving unit
24:: transmission light source
30:: thickness detection sensor
40:: magnetic line sensor
41:: magnetic head
42:: magnetic sensor unit
43:: magnet
50:: optical line sensor
50a:: upper unit
50b:: lower unit
51, 52:: reflection light source
53:: condensing lens
54:: light receiving unit
60:: control unit
61:: optical image generation unit
62:: magnetic image generation unit
63:: main determination unit
64:: determination unit
65:: authenticity determination unit
70:: storage unit
100:: banknote recognition unit (sheet recognition unit)
100a:: standard sensor unit
100b:: optional sensor unit
200:: banknote handling device (sheet handling device)
210:: hopper
211:: feeding unit
212:: transport path
213:: stacking unit
214:: rejecting unit
215:: display
216:: transport surface
BN:: banknote
S:: security element (optical variable magnetic element)
OV:: optical variable feature
M:: magnetic feature
R:: region of security element (optical variable magnetic element)

Claims

A sheet recognition unit for recognizing a sheet with a security element having an optical variable feature and a magnetic feature, the sheet recognition unit comprising:
an optical sensor configured to detect optical information of a sheet;

a magnetic sensor configured to detect magnetic information of a sheet; and

a determination unit configured to determine whether or not an optical variable feature and a magnetic feature are present in a same region of a sheet based on optical information of the sheet detected by the optical sensor and magnetic information of the sheet detected by the magnetic sensor.
The sheet recognition unit according to claim 1, further comprising an authenticity determination unit configured to determine authenticity of the sheet using a determination result from the determination unit.
The sheet recognition unit according to claim 2,
wherein the authenticity determination unit is configured to determine the sheet as a genuine sheet when the determination unit has determined that the optical variable feature and the magnetic feature are present in the same region.
The sheet recognition unit according to any one of claims 1 to 3, further comprising an optical image generation unit and a magnetic image generation unit,
wherein the optical sensor and the magnetic sensor are each a line sensor provided linearly in a width direction of a transport path along which a sheet is transported, the optical sensor defining a first optical line sensor,

the optical image generation unit is configured to generate an optical image based on the optical information detected by the optical sensor,

the magnetic image generation unit is configured to generate a magnetic image based on the magnetic information detected by the magnetic sensor, and

the determination unit is configured to determine whether or not the optical variable feature is present based on the optical image and whether or not the magnetic feature is present based on the magnetic image.
The sheet recognition unit according to claim 4,
wherein the determination unit is configured to compare a shape of a portion with an optical variable feature in the optical image and a shape of a portion with a magnetic feature in the magnetic image.
The sheet recognition unit according to claim 4 or 5,
wherein the optical sensor is configured to detect first reflected light and second reflected light which have been reflected on a sheet,

the second reflected light differs from the first reflected light in at least one of a direction of travel upon incidence on a sheet or a direction of travel after reflection on the sheet,

the optical image generation unit is configured to generate a first reflection image based on optical information of the first reflected light and generate a second reflection image based on optical information of the second reflected light, and

the determination unit is configured to determine whether or not the optical variable feature is present based on the first reflection image and the second reflection image.
The sheet recognition unit according to any one of claims 4 to 6, further comprising:
a second optical line sensor that is configured to detect optical information of a sheet transported and is provided linearly in the width direction of the transport path along which a sheet is transported, and

a main determination unit configured to determine a type and orientations of the sheet,

wherein the optical image is a first optical image,

the optical image generation unit is configured to generate a second optical image based on the optical information detected by the second optical line sensor,

the main determination unit is configured to determine a type and orientations of a sheet based at least on the second optical image, and

the determination unit is configured to identify a region of the security element based on a determination result from the main determination unit and determine whether or not the optical variable feature and the magnetic feature are present in the same region within the identified region of the security element.
A sheet handling device comprising the sheet recognition unit according to any one of claims 1 to 7.
A sheet recognition method for recognizing a sheet with a security element having an optical variable feature and a magnetic feature, the method comprising:
detecting optical information of a sheet;

detecting magnetic information of a sheet; and

determining whether or not an optical variable feature and a magnetic feature are present in a same region of a sheet based on optical information and magnetic information of the sheet which have been detected.