WO2008130111A1

WO2008130111A1 - Apparatus for detecting tape-paste banknote and detecting method the same

Info

Publication number: WO2008130111A1
Application number: PCT/KR2008/001873
Authority: WO
Inventors: Sang Hwan Jang
Original assignee: Kisan Electronics Co., Ltd.
Priority date: 2007-04-20
Filing date: 2008-04-03
Publication date: 2008-10-30
Also published as: KR20080094426A

Abstract

The present invention relates to an apparatus and a method for detecting a tape-attached banknote (currency note or bill) using ultrasonic waves to be implemented in automatic teller machines including currency counters, bill scanners, CDs, BRMs (Bill Recycling Machines), CRMs (Cash Recycling Machines). In particular, the present invention can be advantageously used for sorting out mutilated banknotes, such as, a torn out or repaired banknote that is joined together by tape, in any kind of ATMs provided with a cassette feeder for conveying a number of sheets of bills individually one by one into the machine and a discrimination section for sensing types and conditions of conveyed bills. Since the present invention makes use of ultrasonic waves, not a mechanical structure as in the related art, tape-attached mutilated banknotes are detected at a higher accuracy.

Description

APPARATUS FOR DETECTING TAPE-PASTE BANKNOTE AND DETECTING METHOD THE SAME

Technical Field

[1] The present invention relates in general to an automatic teller machine (ATM) which counts the number of sheets of banknotes deposited in a cassette by sorting them out into individual sheets and recognizes genuine banknotes or types of banknotes, and discriminates mutilated banknotes, more specifically, to an apparatus and a method for detecting a banknote or a bill bonded by tape (hereinafter, referred to as a "tape- attached banknote"), one of key factors for discriminating worn out or mutilated banknotes. Background Art

[2] Technical advances in the manufacturing filed of adhesive tape have gradually reduced the thickness of tape. People often use such a tape to bond torn, a disintegrated currency note to preserve the original note until they go to their local bank to exchange or deposit the torn out bill. Then the bank sorts out those tape-attached bills (e.g., mutilated banknotes) unfit for circulation and discards them.

[3] As many people nowadays use ATMs a lot, ATM is also required to be able to detect any tape- attached banknote at high accuracy. Unfortunately however, an ultra- thin adhesive tape commercially available in the market is already well beyond the limits of existing ATM detection capacities.

[4] A typically used tape-attached banknote sorting mechanism applied to ATM usually adopts a mechanical structure. However, a problem arises in that mechanical structure because ATM which is required for high-speed processing cannot perform a high- accuracy detection.

[5] Fig. 1 is a schematic perspective view of a related art tape-attached banknote detection structure.

[6] Referring to Fig. 1, the tape- attached banknote detection structure according to a related art is designed to recognize a mechanical change and convert the mechanical change into an electrical signal for sorting out any tape-attached banknote.

[7] In detail, a currency note or a bill is inserted and conveyed along a bill convey direction and then passes through a fixed roller 20 and a sliding roller 10 installed on opposite sides. Then, the sliding roller 10 moves in a direction perpendicular to the bill convey direction, in correspondence to the thickness of the bill being conveyed. Depending on how much the sliding roller 10 has moved in the direction perpendicular to the bill convey direction, moving bars 30 start moving with respect to a hinge 40, and sensing bars 50 rotate. Following the rotation of the sensing bars 50, a detection sensor 60 detects the moving distance of the sliding roller 10. The moving distance of the sliding roller 10 corresponds to the thickness of the bill being conveyed. Therefore, when a taped portion of the bill passes between the rollers, the sliding roller 10 moves more. That is, a distance increment is computed in comparison with a moving distance of the sliding roller when a regular bill passes between the rollers as the reference, and the calculated signal is time-shared to detect the length of the tape-attached portion on the bill.

[8] In effect, the above-described mechanical structure and its detection method are implemented the most in ATMs. However, in case a limp or folded bill is inserted, despite its validity and normal condition, the moving distance of the sliding roller increases and the ATM is likely to regard it as a tape-attached banknote. Interesting enough, bills tend to get thicker when they are used under damp, improper conditions over a long period of time. Although those bills are perfectly normal and valid, they might also be regarded as tape-attached banknotes by ATM.

[9] Meanwhile, currency notes being currently issued such as Euro often have a silver line running through the broad area of a note to prevent counterfeiting. In this case, since the silver line imprinted portion of a bill is relatively thicker than the rest portion of the bill, even if an adhesive tape is attached to the surface of the bill other than the silver line imprinted portion, it is difficult for existing ATMs to sort out the bill as a tape-attached banknote. Meanwhile, although a regular euro bill with no taped portion on the surface is inserted, the silver line imprinted portion of the bill affects the moving distance of the sliding roller, resulting in an error detection of tape-attached banknotes. Overall, this impairs the tape-attached banknote sorting performance of ATM. Disclosure of Invention Technical Problem

[10] In view of foregoing concerns, it is, therefore, an object of the present invention to provide an apparatus and a method for detecting a tape-attached banknote at high accuracy using an ultrasonic sensor.

[11] To be more specific, the prevent invention provides an automatic teller machine

(ATM) featuring an improved detection performance for tape-attached banknotes, which implements a thickness detection structure and its method using ultrasonic waves to be able to relatively compare the thickness of a tape-attached portion of a bill with the thickness of a portion of a bill with no tape attached thereto. Technical Solution

[12] In accordance with one aspect of the present invention, there is provided a thickness detection structure for a bill convey path in an ATM, wherein transmission sensors and receiving sensors are arrayed in form of five to twenty pairs on opposite sides from each other at a preset tilt angle (B; approximately 10-25 degrees) with respect to the direction perpendicular to a bill convey direction, and a center-to-center distance (A) between each transmission sensor and each receiving sensor is about 10-20mm, and a distance (C) between an ultrasonic transmission portion and an ultrasonic receiving portion is about 5-30mm. A tape-attached banknote detecting apparatus incorporating such a structure includes: an ultrasonic wave transmission part for generating and transmitting an ultrasonic wave of a predetermined frequency band between 100kHz and 500kHz (preferably between 20OkHz and 300kHz), an ultrasonic wave receiving part for receiving a transmitted ultrasonic wave, an amplifying part for amplifying a received signal to facilitate the detection, a signal processing part for processing a number of amplified signals by the arrival time of a received signal, an analog/digital (AJD) converting part for converting a processed signal into a digital signal, a thickness detection and analysis part for analyzing the intensity of a received signal in use of the converted digital signal to determine whether a bill being conveyed is a tape- attached banknote, and a result processing part for transmitting an analysis result to a main control part.

[13] The present invention can be implemented in an ATM having a structure for receiving separate sheets of bills individually and consecutively at high speed, in which the structure is provided with an ultrasonic transmission part and an ultrasonic receiving part installed on opposite sides with a distance of about 5-30mm between them in a bill convey direction (i.e., the horizontal direction) to maintain a tilt angle of 10-25 degrees each other. Preferably, five to twenty sensors are arranged in plural array form.

[14] To briefly explain the detection method, the ultrasonic receiving part constantly receives ultrasonic waves generated by the ultrasonic transmission part, and the intensity of a received signal by sensors is time-shared to analyze a thickness pattern of a bill being conveyed. In result, it becomes possible to detect an accurate position and length of a tape-attached portion on the bill. Advantageous Effects

[15] The apparatus and method for detecting a tape-attached banknote using ultrasonic waves in accordance with the present invention is implemented in a sorter or installed in a bill convey path of an ATM and can accurately yet efficiently detect the position, length, and area of a tape- attached portion on a bill being conveyed. Brief Description of the Drawings

[16] The above and other objects and features of the present invention will become apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which:

[17] Fig. 1 shows a schematic perspective view of a detection structure for executing a tape-attached banknote detection in accordance with a related art;

[18] Fig. 2(a) shows a perspective view of an ultrasonic transmission part of a tape- attached banknote detection apparatus in accordance with the present invention;

[19] Fig. 2(b) shows a perspective view of an ultrasonic receiving part of a tape-attached banknote detection apparatus in accordance with the present invention;

[20] Fig. 3 shows an exemplary view describing a structure used for a thickness detection operation performed in an automatic teller machine (ATM) in accordance with a preferred embodiment of the present invention;

[21] Fig. 4 shows a layout of internal sensors of a banknote (e.g., currency note or bill) counting device in accordance with a preferred embodiment of the present invention;

[22] Fig. 5 (a) shows an exemplary view explaining a tape-attached banknote detection limit by the number of ultrasonic sensors in a tape-attached banknote detection apparatus in accordance with the present invention;

[23] Fig. 5(b) shows another exemplary view explaining a tape-attached banknote detection limit by the number of ultrasonic sensors in a tape-attached banknote detection apparatus in accordance with the present invention;

[24] Fig. 6 is a flow chart describing how to detect a tape-attached banknote (e.g., currency note or bill) implemented in a tape-attached banknote detection apparatus in accordance with the present invention; and

[25] Fig. 7 (a) through Fig. 9(e) show exemplary views of signal detection in an ultrasonic transmission part for explaining the detection method that is executed in a tape- attached banknote detection apparatus in accordance with the present invention. Best Mode for Carrying Out the Invention

[26] Preferred embodiment(s) of the present invention will now be described hereinafter with reference to accompanying drawings.

[27] Fig. 2(a) and Fig. 2(b) show the structure of an ultrasonic transmission part and the structure of an ultrasonic receiving part, respectively, installed in a tape-attached banknote detection apparatus in accordance with the present invention. An ultrasonic transmission module 160 and an ultrasonic receiving module 150 are positioned on opposite sides, facing each other with respect to a bill convey direction (i.e., the horizontal direction). Ultrasonic sensors 100 provided to the ultrasonic transmission module are ones that are actually involved in transmission of ultrasonic waves of a predetermined frequency (between 100kHz and 500kHz, preferably between 20OkHz and 300kHz) generated by an ultrasonic transmission board 120. The thusly generated signals are received by ultrasonic sensors 100 provided to the ultrasonic receiving module 150 on the opposite side of the bill convey path. A received signal then goes through a series of processing performed in the ultrasonic receiving module 150. To explain in detail by referring to the flow chart shown in Fig. 6, an amplifying part 320 first amplifies the received signal, a signal processing part 330 scans the amplified signal and converts it into a serial signal, an analog/digital converter (ADC) 340 converts the serial signal in form of an analog signal into a digital signal, a thickness detection/analysis part 350 detects and analyzes, based on the digital signal from the ADC 340, the position, area and length of a relatively thicker portion than the rest, regular portion on a bill being conveyed, and a result processing part 360 provides the analysis result from the thickness detection/analysis part to a main control part.

[28] Referring to Fig. 2(a), the distance A between sensors is a key factor related to the accuracy of thickness detection. As an example, for banking machines where high accuracy is valued, such as a currency scanner, a currency counter with a scanning capability, and the like, ultrasonic sensors may be arrayed at the interval of 10- 17mm. On the other hand, for other general-purpose banking machines where high accuracy is not absolutely required, such as a banking machine used for sensing the overlapping or double condition of bills (i.e., two bills stick together and are conveyed as one), so- called double sheet detection, ultrasonic sensors are arranged at the interval of 17mm or more. In short, a narrower gap between sensors realizes the high-accuracy detection of a tape-attached portion on a bill passing between sensors. In the meantime, crosstalk between sensors can likely cause an error in signal detection. In order to get rid of crosstalk between sensors, the present invention apparatus is provided with a shield 130 as a countermeasure against crosstalk.

[29] Referring to Fig. 2(b), the ultrasonic sensors 100 of the ultrasonic transmission module 160 and the ultrasonic sensors 100 of the ultrasonic receiving module 150 are arrayed to be spaced a preset distance C (e.g., 5-30mm) apart from each other, so as to sense an optimum signal. In case the sensors 100 of both the transmission part and the receiving part are installed at positions at right angles to the bill convey direction, reflected waves are synthesized with a received signal, thereby making it difficult to have accurate detection of the thickness of a bill. Because of this, in the case of the present invention apparatus, ultrasonic sensors are tilted at a preset angle B (i.e., 10-25 degrees) from the direction normal to the bill convey path, as shown in Fig. 2(b).

[30] Fig. 3 is an exemplary view describing a structure used for a thickness detection operation performed in an automatic teller machine (ATM) in accordance with a preferred embodiment of the present invention. As an example, a premium type currency counter 200 that has a main pocket and an auxiliary pocket and is capable of recognizing types of banknotes and discriminate brand-new bills from old worn-out bills is depicted. [31] When bills or banknotes are stacked in a hopper 210, equipment starts running and an insertion part 220 inserts separate sheets of banknotes individually into the equipment. Next, an image sensor 230 acquires images of the banknotes to recognize their types. The banknotes then pass between the ultrasonic transmission module 160 and the ultrasonic receiving module 150. According to the processing flow described in the flow chart of Fig. 6 as noted earlier, the detection results on tape-attached banknotes are sent to a main board 240. Later, the main board determines a discharge pocket and controls a switch 250, such that regular bills are discharged to the main pocket 270 while other bills that turned out to have a tape-attached portion of a certain length or area greater than user- set standards in result of the detection are discharged to the auxiliary pocket 260, respectively. In this manner, regular banknotes are discriminated from tape-attached banknotes (mutilated banknotes).

[32] Fig. 4 shows a layout of internal sensors of a banknote (e.g., currency note or bill) counting device in accordance with a preferred embodiment of the present invention. In such a banknote counting device, a number of sheets of banknotes stacked in a hopper 210 are separated into individual sheets by an insertion part 220, and are conveyed to a discrimination part one by one. Next, an image sensor 230 installed at the discrimination part acquires a target banknote image which is then compared with a reference pattern for the device to discriminate the type of the target banknote. Next, the banknote passes a banknote status detection sensor 290, which is usually used as a forgery detection sensor. The banknote then passes between an ultrasonic transmission module 160 and an ultrasonic receiving module 150. Following the processing flow described in the flow chart of Fig. 6 as noted before, the device examines whether there is a tape-attached portion on a banknote being conveyed and transmits the examination result to a control board. In response to a command from the control board, a switch 250 is operated to classify banknotes according to the situation explained in relation to Fig. 3 and discharge them to the pockets 260 and 270.

[33] Fig. 5 (a) and Fig. 5(b) show exemplary views explaining a tape-attached banknote detection limit by the number of ultrasonic sensors in a tape-attached banknote detection apparatus in accordance with the present invention. Referring to Fig. 5 (a), in case of a banking machine the bill insertion direction of which is vertical D, a small number of ultrasonic sensors may be provided to both the ultrasonic transmission module 160 and the ultrasonic receiving module 150 because the position, distance, and area of a tape-attached portion F on the front face of a bill 300 can still be detected. Referring now to Fig. 5(b), in case of a banking machine the bill insertion direction of which is horizontal E, a maximum of 20 ultrasonic sensors may be provided to the ultrasonic transmission module 160 and to the ultrasonic receiving module 150 because the position, distance, and area of a tape-attached portion F on the front face of the bill 300 can still be detected. Meanwhile, in case of sensing only the overlapping or double condition of bills, ultrasonic sensors may be spaced apart from each other by a greater distance.

[34] Fig. 7 (a) through Fig. 9(e) show exemplary views of signal detection in an ultrasonic transmission part for explaining the detection method that is executed in a tape- attached banknote detection apparatus in accordance with the present invention. Each graph in the drawings illustrates the intensity of a signal detected by an individual sensor.

[35] In detail, Fig. 7(a) illustrates an example where there is no banknote between the ultrasonic transmission module 160 and the ultrasonic receiving module 150. In this case, a signal having an intensity of signal waveform I 410 is detected.

[36] Fig. 7(b) illustrates an example where only one banknote 300 passes between the ultrasonic transmission module 160 and the ultrasonic receiving module 150. In this case, a signal having an intensity of signal waveform II 420 is detected.

[37] Fig. 8(c) illustrates an example where one banknote 300 having a tape-attached (F portion) portion at one side passes between the ultrasonic transmission module 160 and the ultrasonic receiving module 150. In this case, a signal having an intensity of signal waveform III 430 is detected.

[38] Fig. 8(d) illustrates an example where one banknote 300 having a tape-attached (F portion) on its front face passes between the ultrasonic transmission module 160 and the ultrasonic receiving module 150. That is, one tape-attached (F portion) banknote covers the front side of a sensor as it passes between the sensors. In this case, a signal having an intensity of signal waveform IV 440 is detected.

[39] Fig. 9(e) illustrates an example where two banknotes 300 pass between the ultrasonic transmission module 160 and the ultrasonic receiving module 150. In this case, a signal having an intensity of signal waveform V 450 is detected.

[40] From the detected signal waveforms I through V shown in Fig. 7 (a) Fig. 9(e), showing an example where there is no banknote between the ultrasonic transmission module 160 and the ultrasonic receiving module 150, an example where only one banknote 300 passes between the ultrasonic transmission module 160 and the ultrasonic receiving module 150, an example where one banknote 300 having a tape- attached (F portion) portion at one side passes between the ultrasonic transmission module 160 and the ultrasonic receiving module 150, an example where one banknote 300 having a tape-attached (F portion) on its front face passes between the ultrasonic transmission module 160 and the ultrasonic receiving module 150 (that is, one tape- attached (F portion) banknote covers the front side of a sensor as it passes between the sensors), and an example where two banknotes 300 pass between the ultrasonic transmission module 160 and the ultrasonic receiving module 150, respectively, one can notice that the intensities of signals detected at the ultrasonic receiving module tend to reduce gradually. In other words, the intensity of a signal detected at the ultrasonic receiving module 150 varies by the thickness of a target object passing between the ultrasonic transmission module 160 and the ultrasonic receiving module 150.

[41] While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.

[42]

Claims

[1] An apparatus for detecting a tape-attached banknote implemented in an automatic teller machine which counts the number of sheets of banknotes deposited by sorting them out into individual sheets and discriminating types of banknotes, the apparatus comprising: an ultrasonic transmission part for generating and transmitting ultrasonic waves of a predetermined frequency; an ultrasonic receiving part positioned on the opposite side of the ultrasonic transmission part in a way to maintain a defined angle, distance, and spacing from the ultrasonic transmission part, for receiving an ultrasonic wave from the ultrasonic transmission part; and an analysis/detection means for detecting intensity of a signal received at the ultrasonic receiving part, amplifying the signal, converting the amplified signal into a time-shared digital signal, and analyzing the intensity of the signal, so as to detect position, length, and width of a tape-attached portion on a target banknote.

[2] The apparatus according to claim 1 , wherein five to twenty sensors are provided in plural array form to the ultrasonic transmission part and to the ultrasonic re ceiving part; and wherein the apparatus is implemented in a banking machine the bill insertion direction of which is either horizontal or vertical, so as to detect a banknote having a tape-attached portion in part, or a fully tape-attached banknote.

[3] The apparatus according to claim 1, wherein the ultrasonic transmission part and the ultrasonic receiving part are tilted at an angle of 10 to 25 degrees from a direction normal to a bill convey path.

[4] The apparatus according to claim 1, wherein a center- to-center distance between the sensors provided to the ultrasonic transmission part and to the ultrasonic receiving part in an array form ranges from 10mm to 20mm, and a distance between an ultrasonic transmission portion and an ultrasonic receiving portion ranges from 5mm to 30mm.

[5] The apparatus according to claim 1, wherein the ultrasonic wave has the predetermined frequency of a frequency band between 100kHz and 500kHz, preferably between 20OkHz and 300kHz.

[6] A method for detecting a tape-attached banknote to be implemented in a tape- attached banknote detection apparatus as described in one of claims 1 through 5, the method comprising the steps of: receiving ultrasonic signals from each of five or more pairs of sensors installed in an array form; amplifying a received signal; processing the amplified signal by a time-sharing manner to output a serial signal; converting the serial signal in form of an analog signal into a digital signal; analyzing intensity of the converted digital signal; and recovering synchronously-received plural signals by a built-in program, and making a relative comparison among signals at each position to detect thickness and to compute position, length, and width of a tape-attached portion on a banknote.