Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H7/00—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles
  • B65H7/02—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles by feelers or detectors
  • B65H7/14—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles by feelers or detectors by photoelectric feelers or detectors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H7/00—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles
  • B65H7/02—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles by feelers or detectors
  • B65H7/06—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles by feelers or detectors responsive to presence of faulty articles or incorrect separation or feed
  • B65H7/12—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles by feelers or detectors responsive to presence of faulty articles or incorrect separation or feed responsive to double feed or separation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H2553/00—Sensing or detecting means
  • B65H2553/40—Sensing or detecting means using optical, e.g. photographic, elements
  • B65H2553/41—Photoelectric detectors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H2701/00—Handled material; Storage means
  • B65H2701/10—Handled articles or webs
  • B65H2701/19—Specific article or web
  • B65H2701/1912—Banknotes, bills and cheques or the like

Definitions

• This invention relates to an apparatus for detecting the passage of multiple documents in a trans ⁇ port system.
• the invention has application, for example, to an apparatus which monitors a currency dispenser in order to detect the simultaneous feeding of multiple bills.
• a major function of any currency dispenser is to remove bills from a stack and present them one at a time to a transport mechanism for delivery to the cus- tomer.
• This function may also be deemed the most criti ⁇ cal, since problems in delivering the bills, such as failure to feed or the feeding of more than one bill at a time, generally begin at this stage.
• problems in delivering the bills such as failure to feed or the feeding of more than one bill at a time, generally begin at this stage.
• a double document detector is described in the IBM Technical Disclosure Bulletin, Vol. 7, No. 8 of January 1965, in which the documents are arranged to pass between a pair of cooperating rollers.
• One of the rollers has an arm attached thereto and is displaceable relative to the other by an extent dependent on the thickness of the documents passing between the rollers. If a single document passes between the rollers, the arm is moved from the home position to a position in which it will not prevent light from passing through an aperture to impinge upon a light sensitive element. When overlapped documents pass between the rollers, the arm is moved to a position to cover the aperture and prevent light from reaching the element, thereby indi- eating an overlapped document condition.
• a disadvantage of this arrangement is that static changes in the position of the rollers, caused by wear, elasticity or accumulation of foreign matter, may result in a drift of the operating range of the system causing erroneous operation.
• an apparatus for detecting the passage of mul ⁇ tiple documents in a transport system including a gaug ⁇ ing means through which documents are arranged to pass, said gauging means being displaceable by an extent de ⁇ pendent on the thickness of one document or multiple documents passing therethrough, characterized by detec ⁇ ting means which is coupled to said gauging means and which is arranged to produce an output whichprogressively ⁇ sively varies in response to a displacement of said gaug- ing means, and circuit means, responsive to said detec ⁇ ting means, for producing an indication of whether multiple documents have simultaneously passed through said gauging means.
• Fig. 1 is a diagrammatic view illustrating certain components of a currency dispenser
• Fig. 2 shows a partial sectional view of the currency dispenser taken along the line 2-2 of Fig. 1;
• Fig. 3 is a schematic diagram of the monitoring circuitry of the currency dispenser
• Fig. 4 shows the unfiltered waveform of a single bill passing through the currency dispenser with its leading edge folded over
• Fig. 5 shows the unfiltered waveform of a double bill passing through the currency dispenser
• Fig. 6 shows the waveforms of several bills as inputs to the doubles detection comparator
• Fig. 7 shows the waveforms of several bills as
• Fig. 8 is a graph of the output voltages of several detectors versus displacement of the film strip
• Fig. 9 is a graph of the normalized output voltage of several detectors versus displacement of the film strip from the energized center position.
• cer- tain components of a currency dispenser there are shown cer- tain components of a currency dispenser.
• O PI ,* A , 1PO or other documents 10 are urged against a table 12 by spring 13 for feeding.
• a pair of spaced-apart driving wheels 14, each located between two adjacent arms of an assembly 16, are fixed to a shaft 18 to be driven there- by.
• currency 10 is urged by driving wheels 14 between a pair of rollers 20 and 22.
• both rollers are composed of an alumi ⁇ num core with a polyurethane covering.
• Feed roller 20 is fixed at the end of a motor shaft 24, which rotates at a surface speed of 250 centimeters per second.
• Idler roller 22 is rotatably mounted on a short shaft 26, which freely rotates in the arms of assembly 16.
• Arm assembly 16 is pivotally mounted on a shaft 28 and tensioned by a spring 30, which spring is' attached to arm assembly 16 at connecting pin 32.
• the opposite end of spring 30 is attached to a short shaft 33.
• Spring 30 applies a force on arm assembly 16 such that roller 22 is urged into cooperating engagement with roller 20.
• roller 22 As currency 10 is fed between rollers 20 and 22, roller 22 is forced away from roller 20 a distance equal to the thickness of the currency 10, causing arm assembly 16 to pivot about shaft 28, and displacing the bottom of arm assembly 16 in the direction toward roller 20.
• the distance between shaft 28 and the bottom of arm assembly 16 is three times greater than the distance between shaft 28 and shaft 26; therefore, the bottom of arm assembly 16 is displaced toward roller 20 three times further than roller 22 is moved away from roller 20 when currency 10 is fed between rollers 20 and .22. Consequently, when using U.S. currency, which has a normal average thickness of 0.010 centimeters, the bottom end of arm assembly 16 will travel approximately 0.030 centimeters when a single bill passes between rollers 20 and 22.
• a processed photographic film strip 34 is bonded along a protrusion 35 on the end of arm assembly 16.
• Film strip 34 is attached to arm assembly 16 such that it moves between the light source and sensor of a detector module 36 as the bottom end of arm assembly 16 is displaced. Since film.strip 34 is processed in such a manner as to exhibit a relatively rapid change in optical density in a direction parallel to its length, the described motion of arm assembly 16 will change the amount of light activating the sensor of module.36.
• the electrical output of detector 36 is relative to the position of arm assembly 16.
• the currency dis ⁇ glutamate is used to detect the presence of a single bill in addition to sensing the presence of multiple bills.
• the home position of rollers 20 and 22 may change. ' Causes for the position drift may be variations in the resilience of the polyurethane surface covering of the rollers, wearing of the surfaces, ink deposits from the bills, wear in the bearings, or changes in ambient temperatures which cause expansion or contraction of the machine base and components.
• Experimental analy ⁇ sis of this home position drift indicates that it may shift plus or minus 0.075 centimeters from its initial position. Therefore, assuming a 0.075 centimeter dis ⁇ placement being necessary for detecting multiple bills, a linear measurement range of 0.225 centimeters is pre- ferred for satisfactory operation of the doubles detec- tor.
• a low-cost and commer ⁇ cially-available component in the circuit of detector 36 which is pre-aligned, and has a sufficiently high elec- trical output to provide direct drive of the associated electronic circuitry.
• a satisfactory component is General Electric type H13B1 photon-coupled interruptor module, which is composed of a gallium arsenide solid- state lamp illuminating a silicon photo-darlington sensor across an air gap of 0.318 centimeters. This component and the film strip provide the entire optical system for the present currency dispenser monitor.
• detector units have an active optical area of only 0.050 to 0.075 centimeters. There ⁇ fore, if the film strip contained a sharp opaque/trans ⁇ parent transition line, the desired range of 0.225 centi- meters could not be reached. To expand the operating range, an incrementally graded density film strip is used.
• a method and apparatus for producing such a film strip is disclosed in an international application filed by the present Applicants on the same day as the present application entitled "Method and Apparatus for Fabricating a Translucent Graded Density Medium” (NCR Docket No. 2905) .
• the film strip having a substantially linear density gradient enables the detector to operate over a greater travel distance. Any movement of the film will cause a change in the intensity of light which the sensor of the detector receives; therefore, the length of the filmstrip determines the operating range of the detector.
• Fig. 3 shows the electronic circuitry which, taken together with detector 36, comprises the monitor control.
• a phototransistor 40 contained within detector 36 acts as a variable resistor between the supply voltage 42, which is filtered by capacitors 43 and 44, and line 45.
• the resistance of phototransistor 40 is controlled by illumination emitted by a photodiode 46 also contained within detector 36. As the illumination from photodiode 46 increases when film strip 34 is moved in one direction within the air gap between the components of detector 36, the circuit voltage becomes more positive across a resistor 47 with respect to ground 48. The voltage on
• line 45 is also applied to a filtering combination of resistor 49 and capacitor 50.
• the coupling capacitor 50 blocks the DC component of the voltage at 45, which voltage is proportional to the quiescent position of film strip 34, arm assembly 16, and roller 22, allowing the circuit to respond only to changes in the position of film strip 34 between the components of detector 36.
• the circuit of Fig. 3 is independent of the static position of rollers 20 and 22, and reacts only to a physical movement of roller 22, which also causes move ⁇ ment of arm assembly 16 and film strip 34; mechanical drift of the static roller position will not affect the proper operation of the circuit.
• Regulator 51 may be an integrated circuit chip, such as Motorola Type MC1723CL or its equivalent, and serves to insure a sufficient calibrated current supply to photo ⁇ diode 46 for proper operation. Regulator 51 and its associated components (resistors 54, 56, 58 and capaci ⁇ tor 60) may be eliminated if the power supply used to drive the circuit is sufficiently stable.
• the output 61 of regulator 51 which is ap ⁇ proximately 8 volts, is applied to another portion of the detection circuitry via resistors 62 and 64 and a diode 66.
• Diode 66 tends to hold the voltage across resistor 64 on the cathode of capacitor 50, which pro ⁇ vides a fast recovery from the charge condition on capacitor 50.
• the voltage at 68 is applied to the non-inver ⁇ ting input 69 of a differential comparator 70 via an integrating network of resistor 72 and capacitor 74.
• Comparator 70 which may be a Motorola type MC1414L or its equivalent, detects the presence of more than one bill between rollers 20 and 22.
• the reference voltage for the inverting input 75 of comparator 70 is generated when the supply voltage at 42 is transmitted across a series combination of a resistor 78 and a zener diode 80.
• the voltage present across zener diode 80 which is approximately 3.3 VDC, is transmitted to the strobe input 81 of comparator 70, and also to input 75 via a resistor 82 and a potentiometer 84.
• Potentiometer 84 makes it possible to adjust the reference voltage for input 75 to a desired level for precise detection of a single bill thickness.
• comparator 70 outputs a fast rising TTL compatible signal at terminal 86 across a load resistor 88.
• Detection of the presence of a single bill is accomplished in a similar manner.
• the voltage at 68 is applied to the non-inverting input 90 of a differential comparator 92 via an integrating network of a resistor 94 and a capacitor 96.
• Comparator 92 may be a Motorola type MC1414L or its equivalent.
• the reference voltage across zener diode 80 is applied to the strobe input 97 of comparator 92, and also to the inverting input 98 via a resistor 100 and a potentiometer 102. Potentiometer 102 adjusts the reference voltage for input 98 to a desired level such that the signal received at input 90 exceeding this reference voltage is indicative of one or more bills passing between rollers 20 and 22.
• comparator 92 when the voltage at input 90 exceeds the reference voltage at 98 by a few millivolts, comparator 92 outputs a signal to terminal 104 across a load resistor 106, indicating the presence of at least a single bill between rollers 20 and 22.
• Fig. 4 shows the waveform of the voltage at 68 when a single bill with the leading edge folded back approximately one-half inch is inserted between rollers 20 and 22. The initial bounce caused as the bill enters rollers 20 and 22 is of sufficient
• FIG. 5 shows the waveform of the voltage at 68 when a double bill travels between rollers 20 and 22.
• the signal in Fig. 5 shows the initial bounce caused by the double bill entering rollers 20 and 22, but the signal also remains at a sufficient level for triggering comparator 70 for a longer time period, due to the extra thickness along the entire length of the bill.
• the initial bounce is softened, allowing comparator 70 to detect only true double bills.
• Fig. 6 shows waveforms of the signals gener ⁇ ated by various bills at input 69 to comparator 70, which signals have been smoothed by the integrating network of resistor 72/ capacitor 74.
• Line 110 repre ⁇ sents the double detection threshold; any signal rising above this will trigger comparator 70.
• Signal 112 represents a double bill with its leading edge folded back approximately one-half inch; it is readily detected by comparator 70.
• Signal 114 shows a double bill; it is also detected by comparator 70.
• Signal 116 represents a single bill with its leading edge folded back approximately one-half inch; the inte ⁇ grating network has filtered the signal so that it will not cause comparator 70 to falsely trigger.
• Signal 118 shows the waveform for an unfolded single bill; it also is not great enough to activate comparator 70.
• the idle noise of the circuitry is represented by signal 120.
• FIG. 7 shows waveforms of the signals generated by various bills at input 90 to com ⁇ parator 92, which signals have been smoothed by the integrating network of resistor 94/capacitor 96.
• Line 121 indicates the present detect threshold; any signal rising above this will trigger comparator 92.
• Signal 122 represents a double bill
• signal 124 represents a single bill with the leading edge folded back one-half inch
• signal 126 represents an unfolded single bill. As shown in Fig. 7, these three signals are sufficiently high enough to surpass the present detection threshold, triggering comparator 92.
• Signal 128 represents idle noise picked up by the cir ⁇ cuitry; it is not strong enough to activate comparator 92.
• Fig. 8 is a graph showing curves 140 and 142 representing the output voltages of two detectors with respect to the displace ⁇ ment of the graded density film strip which is used in the currency dispensor monitor. The graphs show that as the distance from the dark-to-light transition area of the film strip increases the output voltages of the detectors increase in a linear fashion.
• each detector can be normalized in the circuitry of Fig. 3 by adjusting potentiometer 52 until the current through photodiode 46 of the detector module 36 reaches a prescribed level while the output voltage of the phototransistor 40 is held at a fixed level.
• the current level was analytical ⁇ ly and experimentally determined to be 590 microamps using a 4 volt output across phototransistor 40.
• the normalized operating curves 140a and 142a of the detec ⁇ tors used in Fig. 8 are shown in Fig 9.
• the graph of Fig. 9 plots the normalized detector output against the "centered" or normalized position of the film strip. Curves 140a and 142a show that, over a 0.254 centimeter range (+_ 0.127 centimeters from the normalized position), the output voltages of two commercial detectors can be normalized to obtain a uniform response.
• Typical values of the components of the cir ⁇ cuit of Fig. 3 may be as follows:

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• 1980
  • 1980-12-23 WO PCT/US1980/001720 patent/WO1981001827A1/en not_active Application Discontinuation
  • 1980-12-23 EP EP81900285A patent/EP0042860B1/de not_active Expired
  • 1980-12-23 JP JP81500504A patent/JPS56501801A/ja active Pending
  • 1980-12-23 DE DE8181900285T patent/DE3068754D1/de not_active Expired

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