Patent Application
20230138938
This application claims priority from Korean Patent Application No. 10-2021-0149062, filed on Nov. 2, 2021, which is hereby incorporated by reference for all purposes as if fully set forth herein. In addition, research in this application was supported by the SME Innovation Development Project (Project Number: 52872244) of the Ministry of SMEs and Startups in the Republic of Korea.
The present disclosure relates to a banknote sorter and a control method thereof, and more particularly, a banknote sorter capable of accurately determining a banknote to which tape is attached using a contrast ratio (a contrast) of light reflected from the tape and the banknote, and a control method thereof.
vTypically, banknote sorters do not only count banknotes but may also determine whether such banknotes are lawful currency, and whether the banknotes are suitable for circulation or should be discarded. For example, such banknote sorters may determine whether or not the banknotes are suitable or fit for circulating (i.e., new or clean banknotes, circulating banknotes, damaged banknotes, or the like), and whether or not the banknotes are counterfeit banknotes.
To determine a taped banknote among various banknotes in various states of damage, a roller displacement detection method, an ultrasonic transmitting method, a capacitance detection method, an ultrasonic reflection method, a fluorescent image detection method, a polarized image detection method, and the like may be used.
The roller displacement detection method is a most currently used method, but has a problem in that foreign materials attached to the banknote stick to a surface of a detection roller coming into contact with the banknote, and thus cause distortion of the roller displacement detection signal. The ultrasonic transmitting method may have problems in that it is difficult to detect tape attached to the edge of a banknote, and signal distortion can be caused from the banknote by crumpling, creases from folding, and contamination. The capacitance detection method may have a problem in that, with respect to a banknote that includes metallic banknote forgery-preventing elements, it may be difficult to detect tape adhered thereto. The ultrasonic reflection method may have problems in that it may be difficult to overcome the temperature dependence of the speed of sound and a residual vibration characteristic of the ultrasonic sensor. The fluorescent image detection method may have a problem in that it may be difficult to detect tape undergoing a weak fluorescent reaction or that fails to undergo a fluorescent reaction. The polarized image detection method may have a problem in that it may be difficult to detect tape whose surfaces are not smooth and whose mechanical design is not easy.
In this way, methods of determining existing taped banknotes (i.e., damaged or torn taped banknotes) suffer from various problems, and a method of improving these methods and overcoming these problems to allow taped banknotes to be determined at high speed is desired.
Background art that may be relevant to the present disclosure may be disclosed in Korean Patent No. 10-0812254 (registered on 03.04.2008, entitled “PAPER MONEY DETECTOR”).
According to an aspect of the present disclosure, the present disclosure has been devised to overcome the above problems, and is directed to providing a banknote sorter capable of accurately determining a banknote to which tape is attached using a contrast ratio (a contrast) of light reflected from the tape or the banknote, and a control method thereof.
A banknote sorter according to an aspect of the present disclosure may include a light source unit configured to project light obliquely onto a surface of a banknote (e.g., that may be input into and transferred through the banknote sorter) at a first designated angle; a glass configured to allow unhindered transfer of the banknote while refracting the light from the light source unit onto the banknote; a light sensor unit configured to sense the light (e.g., which passes through the glass, is projected onto and reflected from the surface of the banknote, and passes through the glass again) that is incident at a second designated angle different from the first designated angle; and a control unit configured to control the light source unit, process sensing information from the light sensor unit, and determine whether a tape is on the banknote.
A method of controlling a banknote sorter according to another aspect of the present disclosure may include driving a light source unit to obliquely project light at a first designated angle upon a surface of a banknote in the banknote sorter using a control unit; using the control unit, obtaining a banknote surface image from the surface of the banknote through a light sensor unit receiving the light reflected from the banknote, transmitted through a glass, and incident at a second designated angle different from the first designated angle; and using the control unit, processing the banknote surface image to detect a tape region on the banknote.
A banknote sorter according to an aspect of the present disclosure may include a light source unit that generates light to be obliquely illuminated at a designated angle to a surface of a banknote in the banknote sorter (e.g., which may be transferred through the banknote sorter by driving means); a light sensor unit placed to sense the light (which may be irradiated with an inclination of the designated angle onto the surface of the banknote and/or any tape thereon) reflected from the surface of the banknote and/or any tape thereon, and incident onto the light sensor unit at an angle different from the designated angle; and a control unit that controls the light source unit, processes sensing information from the light sensor unit, and discriminates the tape (if any) on the banknote.
According to one aspect of the present disclosure, an entire surface of tape attached to a banknote may be determined using a contrast ratio (a contrast) of light reflected from the tape or the banknote, whereby which remarkably improves the accuracy of determining banknotes to which the tape is attached. Another aspect of the present disclosure simplifies the mechanical configuration for determining a banknote to which tape is attached, to cut down design and production costs.
The above and other objectives, features, and advantages of the present disclosure will be more clearly understood from the following detailed description, taken in conjunction with the accompanying drawings, in which:
For reference, a banknote sorter described in an embodiment according to the present disclosure is used with a conceptual meaning encompassing all various banknote processing apparatuses and systems having one or more functions including recognizing various denominations of banknotes (e.g., $10, $50, $100, ¥10, ¥100, €5, €10, etc.), determining whether banknotes are counterfeit or forged, counting the number of banknotes, determining whether banknotes are fit or unfit for circulation (e.g., depending on the degree of damage such as scribbling, contamination, tearing, or the like), and recognizing serial numbers of the banknotes.
It is noted that the banknote sorter herein can process various types of paper media such as checks, valuable documents, gift certificates, coupons and tickets, as well as banknotes. The banknote sorter is used in places in which a large quantity of banknotes, checks, valuable documents (e.g., merchandise bonds), gift certificates, etc. are circulated, including financial institutions such as bank branches, post offices, money exchange offices, cash-in-transit (CIT) companies, gas stations, amusement parks, restaurants, hotels, department stores, supermarkets, duty-free shops, large retailers, convenience stores, and so on.
Such a banknote sorter is exported to various districts or countries around the world without limit to any district or country, and may be installed and operated there. In the case in which the banknote sorter is installed and operated in the actual place, the banknote sorter can handle various states of banknotes (e.g., new or clean banknotes, old banknotes, crumpled banknotes, banknotes with one or more holes, torn banknotes, banknotes with writing or eternal markings thereon, forged banknotes, contaminated banknotes, discolored banknotes, taped banknotes, and so on).
Hereinafter, a description will be made of embodiments of a banknote sorter according to the present disclosure and a control method thereof with reference to the accompanying drawings. In this description, the thickness of the lines, the size, shape, and the connection relationship of the components in the drawings may be exaggerated or briefly illustrated for clarity and convenience of explanation, and may be conceptually described. In addition, the terms described below are defined in consideration of functions in the present invention, and may vary depending on the intention of the user, or the conventional practice. Therefore, definitions of these terms should be made based on the contents throughout this specification. And throughout the specification, the expressions “˜unit”, “˜er/or”, “˜device”, or the like for the components are not used to limit the present invention and refer to a unit that performs a predetermined function or processes an operation, which may be implemented by hardware, software, or a combination thereof. In addition, it is noted that the contents described for a particular embodiment may be applied to other embodiments.
First, referring to
The present invention makes the contrast ratio difference between the tape and banknote regions larger (e.g., as large as possible). Referring to
Now, referring to
Herein, the light is illuminated onto the banknote at an angle of “a” degrees, and is reflected from the banknote and incident into the light sensor unit 142 at an angle of “a+b” or “a−b” degrees, which is a second light incidence angle. The sensor unit 142 is placed in a position to receive the light incident at the second light incidence angle, in the less bright area, receiving the less bright light. That is, the second light incidence angle may be a misaligned angle of the light, off the centerline of the light, rather than the angle aligned with the centerline of the light. The light illuminated and reflected at an angle of “a” degrees is a first light incidence angle, in the brightest area receiving the brightest light (that is, an angle aligned with the centerline of the incident light). The first light incidence angle may also be an aligned angle.
In addition, it is preferable that the angle “a” has a value in a range from 15° to 50°, and it is further preferable that the angle “a” has a value in the range from 30° to 40°. The tape region detection effect is better when the angle “a” is relatively small. However, if the angle “a” is too small, it becomes difficult to position the light source unit 122 and the light sensor unit 142 in the banknote sorter (e.g., in a tape sensing module [not shown] in the banknote sorter). Alternatively, the light source unit 121 can be moved further to the left in the case of
Now, embodiments of a banknote sorter according to the present invention illustrated in
Meanwhile, rod lenses may be in front of the light sensor units 141 and 142, or be integral (e.g., formed as a single unit) with the light sensor units 141 and 142.
Further, the glasses 131 and 132 may have a designated thickness (e.g., 1.1 mm, 1.8 mm, etc.), and the thickness of the glasses 131 and 132 may change to adjust the angles of light incident upon the light sensor units 141 and 142 (or the reflection angles from the banknote) (see {circle around (1)} “Glass Change” in
The light sensor units 141 and 142 are placed to receive the light at second incidence angles “a+b” and/or “a−b” (i.e., angles that deviate by “b” from the centerline of the banknote/tape light reflection angles to form the less bright area[s], or hereinafter referred to as misalignment angles) rather than first incidence angles “a” (i.e., angles at which the centerline of the light forms the brightest area, hereinafter referred to as alignment angles). As described above, the position of the light sensor units 141′ and 142′ placed to receive the light at the first incidence angles “a” is difficult to expect the effects of the present invention, because the contrast difference between the banknote and tape regions are relatively small.
For example, a method in which the incidence angles of the light on the light sensor units 141 and 142 after being reflected from the banknote (or the tape) and then passing through the glass 131 or 132 are the second incidence angles “a+b” and/or “a−b” may comprise (as illustrated in
In the embodiments described above, the reason why the incidence angles of the light on the light sensor units 141 and 142 after being reflected from the banknote (or the tape) and then passing through or being refracted by the glasses 131 and 132 are the second incidence angles “a+b” and/or “a−b” (or misalignment angles) is that, when sensing the taped banknote using the light sensor units 141 and 142 at second incidence angles “a+b” (or misalignment angles), the light reflected from the banknote (or the tape) has an effect that, due to the contrast ratio (the contrast) of the reflected light, the tape is sensed much more brightly than the banknote region (e.g., such that the banknote region is dark and the tape region is bright).
Further, each of the light sensor units 141 and 142 includes a contact image sensor (CIS). For example, the light source units 121 and 122 may comprise a line array of a plurality (e.g., dozens) of LEDs that emit hundreds of light pulses a second, and the light sensor units 141 and 142 scan and sense such light pulses hundreds of times per second to obtain an image with a resolution of at least dozens of dots per inch (dpi) or more. The control unit 150 identifies the tape region by processing the image and identifying a relatively bright region (see, e.g.,
Further, the light source units 121 and 122 may comprise a plurality of illuminators (e.g., LEDs) in a longitudinal direction at a preset interval (e.g., spaced equally apart in a row), and the illuminators (e.g., LEDs) of the light source units 121 and 122 may irradiate light of at least one wavelength band (e.g., red light, green light, blue light, yellow light, white light, ultraviolet [UV] light, or infrared [IR] light) within a range of wavelength bands of visible light, ultraviolet light, or infrared light.
Although not illustrated in detail in the drawings, an irradiation angle adjusting member (not illustrated) for adjusting an illuminated (projected) angle of light from each of the light source units 121 and 122 may be in front of or on a front surface of each of the light source units 121 and 122.
That is, as illustrated in
In other words,
As illustrated in
Here, in the case in which the light sensor unit 142 is set (placed) so that the light reflected from the banknote or the tape at the alignment angle is incident upon the front center of the light sensor unit 142, the light sensor unit 142 is set (placed) to receive the light incident at the first incidence angle (“a”). In this way, when the light sensor unit 142 receives the light at the first incidence angle “a” (or the alignment angle), it is difficult to expect the tape on the banknote to be sensed significantly more brightly than the banknote.
Thus, as illustrated in
As described above, the reason why or (the principle on which) the above effect can be obtained is because a contrast difference is generated between the banknote region and the tape region according to the difference in the light reflection properties between the banknote and the tape. For example, in the case in which the light (beam) is illuminated to the taped banknote, the light is diffusely reflected from the surface of the banknote, but totally reflected from the surface of the tape. In other words, because the surface of the banknote is fibrous and may be printed with, for example, ink in a pattern, and thus is uneven and rough, light obliquely or slantedly irradiated onto the banknote surface is subject to diffuse reflection. Although there is a difference to a certain degree according to the kind or material of the tape, the tape (i.e., the surface of the tape) is more uniform and smooth than the surface of the banknote, and thus total reflection occurs from the tape surface (at least to a much greater degree than the surface of the banknote, when irradiated at an oblique angle).
In this case, the light source units 121 and 122 are at positions separated by designated distances (e.g., from 5 mm to 9 mm) from the glasses 131 and 132 to illuminate the light at an angle “a” to the banknote, thereby making it possible to further expect the effect caused by the contrast difference (i.e., the effect in which the tape on the banknote is sensed more brightly than the banknote).
The above description has been made of an effect in which the light sensor unit 142 is set (placed) to receive light incident at a second incidence angle “a+b” or “a−b” (or a misalignment angle) so that the tape on the banknote is sensed more brightly than the banknote, in comparison to a first incidence angle “a” (or an alignment angle).
Hereinafter, description will be made to a method of determining the taped region on the banknote on the basis of the effect caused by a difference in the above-mentioned contrast ratio (i.e., an effect in which the tape on the banknote is sensed more brightly than the banknote).
Referring to
Here, as illustrated in
Thus, the control unit 150 produces a banknote image (i.e., banknote surface images) using data from the light sensor units 141 and 142 at designated angles or positions above and/or below the banknote (i.e., the light sensor units set or placed such that light reflected from the banknote through the glass[es] is incident at a second incidence angle “a+b” and/or “a−b”) (S103).
Further, when the control unit 150 processes the obtained banknote images (i.e., banknote surface images) in which a contrast difference generated by the aforementioned effect according to the present disclosure is detected (i.e., the effect that the tape on the banknote is brighter than the banknote) (S104) (e.g., the tape region is detected to be bright, and the banknote region is detected to be dark or less bright), the tape on the banknote is determined (discriminated) (S105). When the control unit 150 does not determine a contrast difference on an image of the banknote, then it is determined that tape is not on the banknote.
In this case, the detection (determination) of the tape region can be performed on the basis of (e.g., in comparison with) several normal (e.g., untaped) banknote templates. However, when the tape region is detected (e.g., on the basis of or with use of a deep learning model generated from performing deep learning while variously changing a position and shape of tape attached to the banknote and a status condition of the banknote), performance of the present invention further improves.
As described above, the present embodiments improve solutions to the existing problems. The present disclosure has been described with reference to embodiments illustrated in the drawings, which are merely illustrative. Those having ordinary skill in the art understand that various modifications and equivalent embodiments are possible. Therefore, the protection or scope of the present disclosure should be defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0149062 | Nov 2021 | KR | national |
