PL197470B1 - Double sheet detector for automated transaction machine - Google Patents

Abstract

An automated transaction machine includes apparatus for distinguishing between single sheets and multiple sheets in a sheet path. The apparatus includes radiation emitters (14, 34) and radiation detectors (20, 40, 42). The radiation emitters are operated to emit radiation at periodic intervals. Signal conditioners (50) receive signals from the radiation detectors and generate outputs responsive to the intensities sensed by the detectors substantially only during the periodic intervals. The outputs are combined, weighed and/or compared to thresholds to distinguish single and multiple sheets. The apparatus enables reliable operation in noisy electrical environments and with a wide variety of sheet properties.

Description

Description of the invention

The present invention relates to a method and apparatus for distinguishing single sheets from multiple sheets composed of a plurality of superimposed sheets.

Automated transaction machines, and in particular automated banking machines, operate with electrical circuits and components containing motors, transformers, relays, electromagnets, and other actuators, all of which generate unwanted electrical signals or noise.

An important task of the automatic banking machine is the issuing and receiving of sheets. Such sheets can be of several types. Banknotes are a common type of sheet issued. Occasionally, two or more banknotes can stick together because of the surface condition of the banknotes or because of moisture or other weather conditions. It is desirable that this condition be detected before the sheets are dispensed. A similar condition may exist in the banknote accepting machines. Two or more banknotes stuck together introduce errors into the banknote receiving processes.

Mechanical methods of detecting thickness have been developed, but changes in the surface properties of circulating banknotes compared to new banknotes make it difficult to measure the thickness of double banknotes. If detection when dispensing sheets is not sensitive enough, multiple sheets may be issued and there is a loss for the operator of the automated banking machine. If the detection is too sensitive, the thicker individual banknotes will be discharged rather than dispensed, with the result that the automated banking machine needs to be refilled more often than necessary.

The electrical and optical detection methods are influenced by electrical noise in the environment of the automated banking machine. Such noise affects the sensitivity with which electrical and optical methods can operate. The signal strength must be large enough for it to be detected above the electrical noise level in the automated banking machine. Increasing the signal strength requires operating with more power. When operating at higher power without compromising sensitivity, and to avoid problems such as signal saturation, components with higher power ratings are needed.

Radiation based sheet thickness detecting devices can deteriorate in accuracy due to color differences in the sheet. For example, a dark colored sheet typically absorbs more radiation than a lighter colored sheet. Different materials used in banknotes of different countries have different radiation absorption properties. This can make it difficult to distinguish between single sheets and multiple sheets. This presents a challenge for automated transaction machines that must distinguish between single and multiple sheets having different radiation absorption and radiation reflection properties.

It is known from US 5,692,067 and US 4,723,072 to distinguish single sheets from multiple sheets composed of a plurality of superimposed sheets, including illuminating the side of the sheet with a radiation source located on that side of the sheet. Also known from the above descriptions is a device for distinguishing single sheets from multiple sheets composed of a plurality of superimposed sheets, having a radiation source on one side of the sheet path and a detector, the radiation from the radiation source being directed to incident on the sheet. on the way of the sheets.

The object of the invention is to provide a method and an apparatus for distinguishing single sheets from multiple sheets composed of a plurality of superimposed sheets, which solutions are highly reliable.

A method of distinguishing single sheets from multiple sheets of a plurality of superimposed sheets, comprising (a) illuminating a first side of a sheet with a first radiation source disposed on the first side of the sheet, according to the invention is characterized by (b) detecting with a detector positioned on the first side of the sheet, a first level of radiation from the first radiation source reflected from the first side of the sheet, (c) detecting by a detector on the other side of the sheet, a second level of radiation from the first radiation source transmitted through the sheet, (d) illuminating the second side of the sheet by means of a second radiation source on the other side of the sheet, (e) detecting by a detector on the other side of the sheet, third level

The radiation from the second radiation source reflected from the second surface of the sheet (f) is generated by means of a composing member for at least one value on the basis of the first level, the second level and the third level, and (g) is compared by means of a comparator. at least one value with at least one threshold, the relationship of the at least one value to the at least one threshold indicates whether the sheet is a single or multiple sheet.

Preferably, in step (c) a detector is used that detects the second radiation level, being the same detector, which detects the third radiation level in step (e).

Optionally, steps (b) and (c) are performed on a first time interval and step (e) is performed on a second time interval.

In particular, the first time interval and the second time interval are non-overlapping.

Preferably, a sheet is used having substantially non-uniform indicia printed on the first and second sides, and the method further includes the step of moving the sheet along the path of the sheets through the detection area, steps (a) - (e) being performed each multiple times. as the sheet passes through the detection area.

Optionally, in addition, a first reflectance value is generated in response to each of the plurality of first reflectance values detected during step (b), and a plurality of first reflectance values are combined to produce a cumulative first sheet reflectance value.

Optionally, furthermore, transmission coefficient values are generated in response to each of the plurality of second levels produced during step (c), and multiple transmission coefficient values are combined to form a cumulative transmission value of the sheet.

Specifically, furthermore, transmittance values are produced in response to each of the plurality of second levels produced during step (c), multiple transmittance values are combined to form a cumulative transmittance value of the sheet, wherein step (f) is at least one weighting factor versus at least one total reflectance value and total transmittance value.

In particular, furthermore, a transmission value is produced in response to each of the plurality of second levels produced during step (c), a plurality of transmittance values are combined to produce a total transmittance value of the sheet, a second reflectance value is produced in response to each from the plurality of third levels produced during step (e), and a plurality of second reflectance values are combined to produce a combined second sheet reflectance value.

Optionally, in step (f), a weighting factor is applied to at least one of the following values: a first total reflectance value, a second total reflectance value, and total transmittance value.

Specifically, in step (f) the weighting factor is applied such that increasing the first total reflectance value and / or the second total beat factor value serves to cause the relationship of at least one of these values and the at least one threshold value compared in in step (g), it tended to point to a multiple sheet.

Preferably, steps (b) and (c) are performed at each of a plurality of first periodic intervals, and step (e) is performed at a plurality of second periodic intervals, with the first periodic intervals not substantially overlapping the second periodic intervals.

Preferably, in step (f), the at least one value is generated by applying at least one weighting factor to the at least one output signal corresponding to at least one of the first, second and / or third levels.

In particular, the at least one weighting factor is applied such that an increase in the output signal corresponding to an increase in the first level and an increase in the third level changes the relationship towards pointing at the multiple sheet in step (g).

Preferably, an infrared radiation source is used as the first radiation source.

Optionally, an infrared radiation source is used as the second radiation source.

PL 197 470 B1

Preferably, the sheet is further advanced along the path of the sheets and discharged from the path of the sheets under the relationship of said at least one value and at least one threshold value compared in step (g), indicating that the sheet is a multiple sheet.

A device for distinguishing single sheets from multiple sheets of a plurality of superimposed sheets having a first radiation source located on the first side of the sheet path and a first detector, the radiation from the first radiation source being directed to incident on the sheet in the sheet path. according to the invention, characterized in that the first radiation source emits radiation substantially only during the first periodic intervals, while the first detector is arranged to examine radiation from the first radiation source which is either reflected or transmitted through the sheet in the way of the sheets, the first being the detector is operable to generate the first signals upon detecting the radiation, and the apparatus has a first signal processing member operably connected to the first signals, the first signal processing member being operative to generate a first output signal in response to the first signal processing member. first signals generated substantially only during the first periodic intervals, a scheduler in operative connection with the first output signal unit, the scheduler acting in response to operation of at least the first unit of output signal to generate a first detected value, and a comparator in operative connection with a first signal processing stage, the comparator for comparing the first detected value and the threshold value, the relationship of the first detected value and the threshold value changing in response to the first output signal, and the relationship between the first detected value and the threshold value indicates whether the detected sheet it is a single or multiple worksheet.

Preferably, the device has a second detector located on the opposite side of the sheet path from the first detector, the second detector positioned to study radiation from a first radiation source that is either reflected or transmitted through the sheet in the sheet path, the latter being the detector is operable to generate the second signals upon the detected radiation, and a second signal processing member operably linked to the second signals, the second signal processing member being operable to generate a second output signal in response to a portion of the second signals that is generated substantially only during the first periodic intervals, the second output unit being in operative connection with the comparator, and the relationship of the detected value and the threshold also vary in response to the second output.

Optionally, the first signal processing member includes a first chopper circuit portion that serves to amplify the first signals substantially only during the first periodic intervals and to suppress the first signals at substantially all other times, the first chopper circuit portion generating the first chopper signals.

Specifically, the first integrator circuit portion includes a first integrator circuit portion to integrate the first chopper signals in a first time period, the first integrator circuit portion producing first integrator signals corresponding to the first output signal.

In particular, the apparatus further comprises a sheet advancing drive, the sheet moving along the sheet path between the first radiation source and either the first detector or the second detector for at least a portion of the first period of time.

Optionally, the device includes a staging member in operative communication with the first and second output signal groups, the staging member acting in response to operation of the first and second output signal groups and generating a detected value.

In particular, the apparatus further comprises a data memory that contains data representing the weighting factors, and the stacking member is operatively connected to the data memory and serves to apply weighting factors to the first and second outputs when generating a detected value.

Preferably, the device further comprises a processor that includes a comparator.

Optionally, the apparatus further comprises a processor in operative connection with a data memory in which data is stored, the processor including a staller, the coefficients

The weights applied to the first and second output signals correspond to the data stored in the data memory.

Preferably, the device further comprises a second radiation source located on the other side of the sheet path than the first radiation source, the second side substantially opposite the first side, and the second radiation source emitting radiation substantially only at second periodic intervals not corresponding to the first periodic intervals. wherein the radiation from the second radiation source is directed to strike the sheet in the sheet path and the second detector is positioned on the other side of the sheet path, and comprises a third signal processing member in functional connection with the second signals, the third processing member signal is for generating a third output signal in response to a portion of the second signals that is generated substantially only at second periodic intervals, and furthermore, the third output signal assembly is operably coupled to the comparator, the relationship of the detected the value relative to the threshold changes in response to the third output.

The subject of the invention has been shown, in exemplary embodiments, in the drawing, in which Fig. 1 shows a schematic side view of a radiation source and a radiation detector, the detector detecting radiation reflected from the sheet surface, Fig. 2 - a schematic side view of a radiation source, the first a radiation detector for detecting radiation reflected from a surface of a sheet and a second radiation detector for detecting radiation transmitted through the sheet; Fig. 3 is a schematic view of an exemplary synchronized discriminator circuit having a radiation source driver stage, a preamplifier stage, a synchronized chopper stage, and an integrator stage, Fig. 4 - a signal having a high state and a low state for impulse control of the radiation source and detectors shown in Figs. 1-3, Fig. 5 is a schematic view of an exemplary automatic transaction device including a device according to Figs. Fig. 6 is a schematic view of a first alternative embodiment of the invention comprising two radiation emitters, the first emitter producing radiation incident on the sheet, Fig. 7 is a schematic view of the alternative embodiment shown in Fig. 6 with an alternative emitter shown in a state of emitting radiation. Fig. 8 is a schematic view showing the waveforms used to control the emitters in the embodiment shown in Fig. 6, the waveforms including periodic intervals in which the emitters produce radiation, Fig. 9 is a schematic view of the processing, weighing, combining and comparison members. 6, Fig. 10 is a schematic view of exemplary signal processing members used in an alternative embodiment of the invention, and Fig. 11 is a schematic view of emitters and detectors used in conjunction with a further alternative embodiment of the invention.

In the drawings, and more particularly in Fig. 1, the radiation source and reflected radiation detector assembly 10 and the sensing sheet elements 12. The sheet 12 is typically a banknote, bill, coupon, ticket, or other document or sheet representing a value. The radiation source 14 causes schematically indicated radiation 16 hitting the surface of the sheet 12. The schematically marked reflected radiation 18 is detected or otherwise sensed by detector 20. The signal from detector 20 corresponds to the intensity level of the reflected radiation.

Another embodiment of the invention is shown in Fig. 2. It comprises a radiation detector assembly 30 including a radiation source 34, a reflected radiation detector 40, a transmitted radiation detector 44, and a detected sheet object 12. The radiation source 34 causes the schematically indicated radiation 36 to fall on the sheet surface. 12. Some of this radiation 36 will be reflected from the surface of sheet 12 and some will pass through the sheet. The principle of the present invention is that the intensity of the radiation 38 reflected from the defined area to which the radiation is directed is substantially proportional to the thickness of the sheet 12 under examination, while the intensity of the transmitted radiation 42 is substantially inversely proportional to the thickness of the sheet. Both the intensity of reflected radiation 38 and the intensity of transmitted radiation 42 are substantially inversely proportional to the "darkness" or radiation-absorbing properties of the sheet 12 in the area of interest.

PL 197 470 B1

In the embodiment shown in Fig. 2, reflected radiation 38 is detected by the reflectance detector 40. The transmitted radiation 42 is detected by a transmission coefficient detector 44. The reflectance detector 40 and the transmittance detector 42 produce signals indicative of the detected radiation intensity level. Combining or otherwise processing these two signals as described later improves the detection of the thickness of the sheet 12 to distinguish a single sheet from a sheet that is composed of two or more sheets superimposed on each other.

Preferably, the sources 14, 34 shown in Figures 1 and 2 are infrared light emitting diodes. The radiation beams 16, 36, the reflected beams 18, 38 and the transmitted beam 42 are therefore also preferably infrared radiation. The radiation detectors 20, 40, 44 are preferably photo diodes or photo transistors suitable for detecting infrared radiation. It should be understood that other types of radiation sources and other types of detectors, including both visible and invisible radiation sources, may be used in other embodiments.

As shown in Fig. 3, the synchronized discriminator of one exemplary embodiment includes a signal processing unit that includes a driver 60, a preamplifier 70, a synchronized chopper 80, and an integrator 90.

The driver 60 includes a circuit having a transistor 65 and resistors 66, 68. The driver 60 also includes a radiation source 62, which is preferably an infrared light emitting diode. Source 62 is pulsed on a sync signal 100 having a selected waveform. The synchronization signal 100 is supplied to the driver input 69. The waveform of one preferred sync signal 100 having a high state and a low state is shown in FIG. 4, but other sync signals may be used. For example, one such waveform is a series of pulses with a 50% duty cycle. As described above with reference to FIG. 2, a portion of the radiation generated by the sources 62 will be reflected from the medium 12 as a reflected beam 38, and a portion will be transmitted through the medium 12 as a transmitted beam 42.

The preamplifier stage 70 includes the amplification circuit shown. It comprises a photodiode 72. The photodiode 72 produces signals corresponding to a detected level of radiation intensity. The diode 72 can therefore produce signals corresponding to the reflected beam 38 or the transmitted beam 42. The preamplifier stage further includes an opamp 74. A phototransistor or other signal generating sensor element may also be used in place of a photodiode 72. The output of op amp 74 is applied to a timed chopper 80.

The synchronized chopper 80 in this exemplary embodiment includes an operational amplifier 82 with a positive input resistor 87, a negative input resistor 88, and a feedback resistor 89. An analog switch 84 is connected to the positive input of op amp 82. This analog switch 84 is driven by a sync signal 100 at input 86. When sync 100 is high, analog switch 84 is turned on, thereby shorting the positive input of op amp 82 to ground. Shorting the positive input to ground causes the op amp 82 to become a -1 gain analog inverter. When the sync signal 100 is low, the analog switch 84 is turned off and the op-amp 82 is a +1 gain follower. The output of the op amp 82 is the input of the integrator stage 90.

The integrator 90 in this exemplary embodiment includes an operational amplifier 92 with a positive input resistor 93, a negative input resistor 94, and a feedback capacitor 95. The output signal 110 of integrator 90 results from signal processing corresponding to a calculation that favors signals substantially in sync with sync signal 100. In alternative embodiments, a bandpass filter may be used in place of integrator 90.

A useful aspect of the synchronized discriminator in accordance with the embodiments of the invention is that any signal that is not substantially in synchronization with the synchronization signal 100 will be attenuated. The synchronized discriminator 50 of this embodiment is both frequency and phase sensitive. Unlike the bandpass filter itself, which cannot remove noise in the passband, the timing discriminator 50 according to the embodiment suppresses noise signals that are essentially not of the same frequency and phase as the timing signal 100.

PL 197 470 B1

In the exemplary timed discriminator 50 a spool signal 98 designed to discharge jumper 96 through capacitor 95 is applied to bias integrator 90. The spotting signal is generally provided such that the integrator is reset for each sheet or sheet portion being analyzed.

The output 110 of the integrator 90 is the output of the synchronized discriminator 50. The output of the synchronized discriminator 50 may be expressed as t

y (t) = k J f (t) g (t) dt 0 where g (t) is the sync signal, f (t) is the noise signal detected by photodiode 72, and k is the constant. When the sync signal is a square wave, shown in FIG. 4 as sync signal 100, g (t) is either +1 or -1 in the sync discriminator 50. Thus, for each sheet as it passes, timing discriminator 50 produces a signal that amplifies the signals from the photodiode 72 synchronized in frequency and phase with the output of radiation source 62. Other signals that represent noise are suppressed.

It should be understood that the synchronized discriminator circuit 50 is exemplary. In other implementations, other forms of circuit and other signal processing devices may be used to distinguish between detector signals that are substantially frequency and phase synchronized with the source of the signal of interest, and to suppress other signals. The signals produced by the radiation detectors 20, 40 and 42 may be processed by a synchronized discriminator. As a result, the separate outputs represent the transmission and reflection properties of the sheet in the area of the sheet that is irradiated. In preferred embodiments of the invention, when used in conjunction with automated banking machines, the sheet's transmission and reflection properties are tested as the sheet is advanced in the path of the sheet relative to the radiation source and sensors. The sheets may advantageously be advanced one at a time along the path of the sheets by any sheet handling device such as belts, rollers, pick-up mechanisms, or combinations thereof.

The outputs of the synchronized discriminators, which represent the transmission and reflection properties of the sheets, can be combined or otherwise processed together to define those situations where double or other multiple sheets pass the sensor instead of a single sheet. Multiple sheet detection is often needed in automated banking machines where notes or other sheets are picked up from the warehouse essentially one at a time by a pick up device to be delivered to the user. However, due to a malfunction or other sheet properties, multiple sheets are sometimes picked up. Detection of such multiple sheets allows them to be recycled or separated at the device, or to be prevented from being delivered to the user.

As described above with reference to Fig. 2, the intensity of reflected radiation 38 is proportional to the thickness of the sheet 12, and the intensity of transmitted radiation 42 is inversely proportional to the thickness of the sheet 12. Both the intensity of reflected radiation 38 and the intensity of transmitted radiation 42 are inversely proportional to the darkness. (color distribution) of the sheet 12. Combining the signals corresponding to the intensity of the reflected beam 38 and the transmitted radiation 42 with different weights improves the distinction between single sheet detection and the detection of double or other multiple sheets with the detected sheet 12. The intensity of the reflected beam 38 is used for color and pattern recognition. sheet surface (e.g., the relative darkness of the color of the detected sheet) and to improve the detection of double sheets. As a result, determining whether the detected sheet is single or double made on the basis of the combined signals will be more sensitive to thickness and less sensitive to color.

It can be seen that the synchronized discriminator described herein and its operation can also be used for other sensor applications to achieve better signal-to-noise ratio, higher detection sensitivity and lower power consumption. The principles of the present invention are particularly useful in those applications where ambient noise or signal interruptions are a problem.

The signals representing the levels of transmission and reflectance may be combined or otherwise processed separately or together in various ways and used to distinguish whether the detected sheet is a single or double sheet.

PL 197 470 B1

The approach used depends on the nature of the sheets detected and the analysis being performed. For example, each of the signals corresponding to the transmittance and reflectance values produced by the synchronized discriminator can be converted into digital signals by an analog-to-digital converter. The digital signals may then be weighted, compared, or otherwise processed together by a processor or other signal processing device based on programmed commands. Determining whether the detected sheet is single or double (or other multiple) can be made by the processor based on comparing the measured value corresponding to the radiation data to be tested with one or more fixed or programmable thresholds. In general, the approach to combining or evaluating the signals and thresholds in deciding whether the test sheet is single or double is taken from experience with single or multiple sheet types that are supported by the apparatus. The reflectance and transmission coefficient signals produced in response to sheets of the same type in a single or multiple state allow the determination of weighting factors applied to the signals and threshold data that represent the states of the sheets and can be used to distinguish whether the detected sheet is single, double or other multiple.

Processing the transmission and reflection signals as digital signals according to programmed commands has the advantage that in the same device in response to different programmed commands, different weights can be easily assigned to the signals and different approaches to signal combination and threshold comparison can be used. The use of such commands may be selectively triggered by input signals that indicate the type of the sheet, including, for example, inputs indicating the source of the sheet in the device, devices on the sheet path that determine the type of the sheet from the characters on it or inputs from the user.

While processing of signals representing detected reflected and transmitted radiation into digital signals is discussed, other approaches can be used. A circuit may be used that weighs and combines the analog output signals with timed discriminators and compares such detected value outputs to one or more thresholds representing the detection of double or other multiple sheets of a particular type. It should be understood that when referring to a detected value based on the detected sheet data, it may be one or more values and when referring to a threshold it may be one or more thresholds.

Moreover, in some embodiments, the output of the synchronized discriminators may be combined and processed over substantially the entire length of the passing sheet. This can be done by resetting the integrator in response to the detection of the sheet leading edge. It may be triggered in response to a decrease in the transmittance value, an increase in the reflectance value, or by a separate sensor mechanism that signals the presence of the sheet at the detector assembly. Likewise, the signal is no longer integrated when the sheet is no longer detected. Alternatively, signals representing transmission and reflectance may be processed on a single part or on multiple selected parts of the sheet that are smaller than the entire sheet. Alternatively, the signals corresponding to the radiation levels for each detector may be accumulated on the sheet or part thereof and the accumulated values weighted, combined or otherwise processed. The approach used will depend on what is considered appropriate for a given type of sheet to distinguish between single sheets and multiple sheets.

Although, in the described embodiment, the signals from the radiation detectors are processed by signal processing units that include synchronized discriminators to produce output signals that are combined with the weighting factors used, other embodiments may operate differently. For example, the signals resulting from the intensities of radiation reflected from or transmitted through the sheet may be weighted and combined before being fed to a signal processing unit that provides a synchronization-sensitive output signal at periodic intervals in which the emitter emits radiation. In addition, while the signal processing units described include a chopper, an amplifier, and an integrator, other embodiments of the signal processing units may be used in other embodiments.

In some preferred embodiments, the signal-to-noise ratio of the radiation detectors may be increased by a factor of 100. However, since the signal-to-noise ratio

PL 197 470 B1 is increased, there is a corresponding increase in the integration time. The longer the integration time, the greater the signal-to-noise ratio will be. This ratio is limited by the time that a certain position of the sheets can be detected and by the saturation level of the integrator.

The present invention is preferably used in conjunction with automatic transaction machines. For the purposes of this description, automated transaction machines include any equipment that is used to carry out a value transfer transaction. For example, an automated banking machine in which the present invention may be used is an automated banking machine. Fig. 5 is a schematic view of an exemplary transaction device 112 that includes an embodiment of the present invention. This transaction machine includes a stock of sheets 114. The sheets are received in a cassette or bin 116. The sheets are generally ejected from the bin one at a time through a pick mechanism 118. The pick mechanism 118 may be of the type generally shown in US 4,494,747. but any of many different types of picking mechanisms can be used.

A pick mechanism 118 is provided to selectively feed sheets one at a time into a path of 120 sheets. A drive mechanism including opposing belts 122 serves to advance the sheets in the path of the sheets. The drive mechanism is driven by a motor 124 or similar drive device.

The sheet detection mechanism of the present invention is schematically designated 126 in an exemplary apparatus. The sheet detection mechanism 126 extends along the path of the sheets to detect radiation transmitted through and reflected from sheets passing through its detection region. The sheet detection mechanism 126 is operatively coupled to a processor 128. The processor 128 has a data memory 130 operatively coupled to it. In this exemplary embodiment, the processor serves to receive the output signals corresponding to the radiation intensity values. The processor is for calculating a measured value corresponding to the outputs, which may include one or more values. The detected value is compared with one or more threshold values which are determined from the data stored in the data memory.

Under the relationship of the at least one measured value and the at least one threshold value, processor 128 operates according to its program to determine whether the detected sheet is a single sheet, deliverable to the user, or is a double or other multiple sheet to be distinguished. and keep inside the machine. The processor 128 is operatively connected to a discharge channel which includes a gate 132. When the detected sheet is a single note, the discharge channel gate is in the position shown in Figure 5. As a result, the sheets are directed to the second part of the sheet path, schematically designated 134. the other part of the sheet path 134 ends in the delivery area 136. Sheets from the delivery area are delivered to the user of the machine.

If the detected value based on the radiation intensities detected by the sheet detection mechanism means that the sheet moving through the sheets is doubled or otherwise multiple, or it is a bad sheet, then the processor 128 causes the discharge channel gate 132 to move to a position where the sheets are. discharged from the other part of the sheet path. The discharge chute gate then serves to guide the sheets to the discharge bin 138. The sheets are stored in this container until they are removed by authorized personnel having access to the interior of the automated transaction machine.

While the described embodiment of an automated banking machine is an automated banking machine, the present invention may be used with many different types of automated transactional machines that dispense or receive sheet materials having radiation properties that vary with thickness. In addition, while the described embodiment uses radiation to determine the thickness of the sheet, other types of sensors may be used in other embodiments. For example, for suitable sheets, emitters and optical sensors and other types can provide a suitable indication of the state of the sheets. In addition, the principles of the invention may also be used to suppress foreign signals from mechanical type detectors, including detectors that inspect the thickness of the sheet with members contacting the sheets.

PL 197 470 B1

Figure 6 shows an array of radiation emitters and detectors in an alternative embodiment of the sheet detection device of the invention. This alternative arrangement, generally designated 140, includes a first radiation source, denoted emitter 142. A radiation emitter 142 is located on the first side of sheet 144. The first radiation detector 146 is located on the same side of the sheet as the emitter 142. Another radiation detector 148 is located on the opposite side of sheet 144 from emitter 142.

As shown in FIG. 6, when the emitter 142 emits radiation, the radiation strikes the sheet surface and is partially reflected and detected by detector 146. A second portion of the radiation is passed through the sheet and detected by detector 148. The detector 142 emits radiation periodically. These periodic radiation intervals are schematically represented by positive pulses in waveform 150 in FIG. 8.

The embodiment 140 also includes a further radiation source represented by the emitter 152. The emitter 152 is positioned such that the radiation emitted by it is incident on the opposite surface of the sheet 144 as the sheet moves through the sheets. Some of the radiation from the emitter 152 is reflected to the detector 148. A small portion of the radiation from the emitter 152 is also transmitted through the sheet. However, because of the angle of incidence of radiation from the emitter 152 in the illustrated arrangement, relatively little radiation passes through the sheet and the transmitted radiation from the emitter is not analyzed in this embodiment.

The emitter 152 is activated by a control signal to emit radiation at second periodic intervals. These second periodic intervals are represented by waveform 154 in FIG. 8. It should be noted that waveform 154 is preferably out of phase with waveform 150, such that emitter 142 does not emit radiation at the same time as emitter 152, however. in other embodiments where the emitters emit different types of radiation such that the detector (s) for one emitter is substantially beyond the interaction of radiation from the other emitter, the waveforms may overlap.

Figure 9 schematically shows the components of the signal processing and analysis devices in conjunction with the alternative embodiment 140. The detector 146 is in operative connection with the first signal processing unit 156. This signal processing unit 156 may include components comparable to the timed discriminator described previously, or another suitable signal processing system. The signal processing unit may include a driver that controls the emitter 142 to emit radiation at the first periodic intervals represented by waveform 150, or it may be coupled to such a driver. The signal processing unit 156 is operable to synchronize the detected signals from the detector 146 with the emission of radiation from the emitter 142 using a chopper or other device.

Signal processor 156 may also include an amplifier and an integrator similar to a synchronizing discriminator previously described to amplify and integrate signals in response to radiation detected by detector 146. In some embodiments, signal processor 156 may be used to integrate signals corresponding to signals of detected radiation. from the detector at periodic intervals that include the time sheet 144 is in the detection area in the sheet path at the detectors and emitters. Of course, in alternative embodiments, integration across less than the entire length of the sheet may be used.

Although the signal processing unit 156 may include components similar to or function the same as those of the synchronizing discriminator, the signal processing unit 156 may also include other components. Such components may include, e.g., an analog-to-digital converter, processor, or other circuit or members that are used to sample and pass only signals corresponding to the radiation detected while the emitter 142 is emitting radiation, and to suppress or reject other signals. The components of the signal processing unit 156 will also depend on the nature of the emitters and sensors used, and possibly the characteristics of the sheets. It should also be mentioned that, in fact, the time at which the radiation signals from the sensor 146 or other sensors are sampled and analyzed need not necessarily exactly match the periodic intervals in which the emitter emits radiation. It is sufficient for the signals from the detectors to be analyzed essentially only while the emitter of interest is producing the radiation. Favorable results can still be obtained when the signal analysis time is shorter than the emission time of the emitter and / or not exactly in phase with it.

As shown in Fig. 9, detector 148 is operatively connected to signal processing unit 158. The signal processing assembly 158 in the described embodiment may be similar to the assembly

PL 197 470 B1

156 signal processing. Signal processing unit 158 is operable to produce an output in response to radiation detected by detector 148 at intervals in which the emitter 142 emits radiation. Like signal processing unit 156, signal processing unit 158 is operable to produce an output signal corresponding to the radiation detected by detector 148 at a selected time.

Emitter 152 and detector 148 are also operatively connected to signal processing unit 160. The signal processing unit 160 is for generating the control signal or is otherwise operably coupled to a control signal source that causes the emitter 152 to generate radiation according to the waveform 154 shown in Fig. 8. Signal processing unit 160 is substantially similar to processing units 156 and 158. signal. However, the output signal it produces represents the light reflected by the sheet from the emitter 152 during the second periodic intervals in which the emitter 152 produces radiation.

It should be noted that the sheet detector configuration 140 serves to provide an indication of darkness or radiation absorption on both sides of the sheet as the reflected radiation intensity value is inversely proportional to the darkness of the sheet material. The availability of reflectance data on each side of the sheet is useful in detecting double sheets of some kind.

In the exemplary implementation, the outputs of the signal processing units 156, 158, and 160 are operatively coupled to interconnecting device 162. The combining device serves to apply weighting factors to the outputs and / or to combine the signals by methods suitable for detecting double sheets according to recorded data. in data memory 164. The combiner 162 in the described exemplary embodiment forms part of a functional software component running on the processor 166. Of course, it should be understood that other types of linking and weighting devices may be used in other implementations.

The combiner is operable to use the information of the output signal to produce a detected value that includes one or more values or signals resulting from combining the output from the signal processing units. The detected value is then output to comparator 168. The comparator is used to determine the relationship of the detected value to a threshold, which may include one or more thresholds indicating conditions such as single sheets, double sheets, triple sheets, etc. In other embodiments, the threshold may be used to distinguish a single sheet from a multiple sheet. In other embodiments, the threshold may be used to distinguish a single sheet from a multiple sheet. It should be understood that the combiner and comparator may, in some embodiments, operate together to set both the detected value and the threshold relative to the outputs from the signal processing units. For example, the high dark outputs on the sides of the sheet can be used to set the threshold such that a relatively less amount of radiation detected as traversing the sheet does not amount to double sheets under circumstances where a similar amount of radiation traversing the less dark sheets would be double sheets. Depending on the specific detection sheets and on the system software, different approaches can be used to combine the outputs from the signal processing units and to set the detected value and threshold relationship. These approaches to combining and weighting output signals and to setting and adjusting thresholds are preferably established from experiments with single and multiple sheets of machine-detectable types to determine the range and type of signals received from acceptable single and multiple sheets or superimposed on them. each other.

Comparator 168 is operable to output signals corresponding to a comparison of the relationship between a detected value and a threshold. If the comparator determines the probable existence of a double sheet, the signals output from the comparator serve to cause the device to take appropriate action. This may include, for example, activating a drain channel 132 shown in Fig. 5 to guide the duplicate sheets into a drain bin 138.

It should be understood that the arrangement and types of components shown in Fig. 9 are exemplary and that other hardware and software solutions may be used in other embodiments of the invention. It should further be understood that the embodiment of the invention described herein with one emitter and two detectors may also be as shown in Fig. 9. Of course, such an arrangement will not employ the third signal processing unit 160 and the combining apparatus will be

PL 197 470 B1 was used to combine the synchronized signals output by the other two signal processing units. It should further be understood that while in conjunction with the embodiments disclosed herein, the radiation from the emitters is sometimes described as a beam and is generally shown to be linear, the radiation sources and radiation signals therefrom may take a variety of forms, including conical, fan-shaped, or other suitable shapes. to fall on the sheets passing on the sheet path. It should be understood that in the embodiments of the invention, the emitters used may generate substantially single frequency or multi-frequency radiation. In alternative embodiments that use emitters that produce substantially different types of detection signals so that they can operate simultaneously, different or additional detectors may be used on each side of the sheet to detect the signals from the respective emitter.

Figure 10 shows a system 180 that is substantially similar to the system 140 of Figure 9 but employs alternative signal processing devices and methods. In system 80, radiation sources 142 and 152 are controlled by substantially non-overlapping control signals 150 and 154. As in the previous embodiment, detector 148 examines the level of radiation transmitted through the sheet from source 142 when source 142 is triggered by a control signal. 150. Detector 148 also examines the level of radiation reflected from the sheet opposite surface from source 152 when source 152 is driven by signal 154. Detector 146, which is located on the same side of the sheet path as source 142, examines the level of radiation reflected from the opposite surface of the sheet. when source 142 is driven by signal 150.

In system 180, the preamplifier 182 amplifies and converts the current signals produced by the photodiode used as detector 148 and converts the current into a voltage signal. Preamplifier 184 similarly amplifies and processes current signals from the photodiode used as detector 146 and produces a voltage signal in response thereto.

The output of the preamplifier 182 is fed to a correlation discriminator 186. This correlation discriminator 186 operates in a toggle mode to filter out noise and interference in frequency and phase. The switching is performed by pulse correlation 188, which corresponds to the combination of waveforms 150 and 154. Switching correlation discriminator 186 due to pulse correlation 188 demultiplexes the transmission signal and reflection signals generated in response to transmitted and reflected radiation detected by detector 148.

A signal corresponding to the radiation level found for the radiation passing through the sheet to detector 148 is fed to an amplifier 190 with a low-pass filter. A signal corresponding to the level of radiation reflected from the sheet to detector 148 is applied to amplifier 192 with a low pass filter. The outputs of the amplifiers 190 and 192 are applied to one or more analog-to-digital converters in this exemplary embodiment. This results in at least one value representing the levels of radiation detected by detector 148 that may be compared, applied weighting factors, or further processed to distinguish between single and multiple sheets.

The output from the preamplifier 184 corresponding to the radiation level detected by detector 146 is applied to the correlation discriminator 194. This correlation discriminator 194 is switched in switching mode by pulse wave 188 and preferably passes signals corresponding to the frequency and phase to the source 142 driving pulses. This filters out the result. noise by passing only those signals that are frequency and phase synchronized with the control waveform.

The output of the synchronized discriminator 194 is fed to an amplifier 196 with a low pass filter. The output of this amplifier 196, which is a measure of the level of radiation reflected from the banknote surface at the source 142, is then applied in this embodiment to one or more analog-to-digital converters. The appropriate digital signal is then combined, weighted, and / or processed with other signals to determine whether the inspected sheet is a single or multiple sheet.

In this exemplary embodiment, the digital signals corresponding to each signal representing the sheet transmission level are accumulated to produce a cumulative transmission value representing radiation transmitted through the sheet or a portion thereof being analyzed. Likewise, each of the surface reflectance values

The sheet is combined to form the appropriate cumulative reflectance values. These values represent the reflectance over the entire sheet surfaces in the parts analyzed. These cumulative values can then be processed by applying weighting factors which implement the principle that less radiation will be transmitted through the sheet when the sheet color is dark when tested by the reflectance value. The weighting factors are also advantageously used to introduce the rule that the sheet reflectance level will be the greater the greater the sheet thickness, as indicated by a multiple sheet. By applying the weighting factors that implement the principles discussed, the values can be individually compared to thresholds or combined into one or more values and compared to one or more thresholds to determine whether the sheet under test is a single or multiple sheet.

Alternative approaches may include weighing and combining sets of individual transmission and reflectance values to obtain compensation for each local area of the sheet under inspection. This may involve weighing and combining the values in a set of one transmittance value and two reflectance values. Alternatively, this may involve combining and weighting groups of reflectance and transmission values. Using such approaches, values can be produced that can be compared to thresholds many times during a banknote examination. The conclusion as a result of these comparisons can then be used to determine whether the worksheet is a single or multiple worksheet. Various approaches to combining, weighing and processing the signals from the detectors can be used to make comparisons with thresholds and determine whether the sheet under test is a single or multiple sheet.

Many embodiments are within the scope of the present invention. Embodiments of the invention may be used to pass single sheets through and discharge or otherwise prevent the delivery of multiple sheets that are wholly or partially overlapped. Since embodiments of the invention can be used to obtain an indication of the sheet thickness, they can also be used to pass identified multiple banknotes under circumstances where this is acceptable. This can be done in a manner similar to that previously used with the mechanical thickness detectors disclosed in US Pat. Nos. 4,464,369 and 4,462,587.

Figure 11 shows yet another alternative arrangement of emitters and detectors in the sheet detection apparatus of the present invention. This further alternate arrangement, generally designated 170, includes an emitter 172 and an emitter 174. This alternate arrangement further includes a detector 176 positioned on the same side of the sheet path as the emitter 172.

Detector 178 is located on the same side of the sheet path as the emitter 174. The detected sheet is schematically designated 179. As the sheets pass between the emitters and detectors in the sheet path, the emitter 172 and emitter 174 are controlled to emit radiation preferably substantially non-overlapping. each other at periodic intervals of the first and second. When the emitter 172 emits radiation, the signals from detectors 176 and 178 are processed and synchronized with each other to analyze the transmission and reflection properties of the sheet against the radiation hitting the sheet from the first side of the sheet path. At substantially non-overlapping second periodic intervals where the emitter 174 is emitting radiation, detector 178 and detector 176 examine the intensity of reflected and transmitted radiation from the emitter 174 on the opposite side of the sheet path from the emitter 172.

It should be noted that this alternative circuit 170 produces four outputs that can be weighted, combined, or otherwise analyzed to determine if an adjacent sheet has single, double, or other multiple sheet properties. The weighing of the signals and the determination of thresholds for the purposes of deciding on the sheet conditions are preferably performed on the basis of data obtained experimentally with the sheets of interest. Of course, it will be appreciated that other numbers and types of detectors and other emitter and detector arrays may be used in other embodiments of the invention. Further, as discussed in relation to other embodiments, if the emitters used are of a type that sufficiently differ in the frequency of the radiation or other emitted signals, it may be acceptable to have periods in which the emitters operate and significant overlap is detected. degree.

PL 197 470 B1

The method and apparatus according to the invention thus achieve the objectives set out above, eliminate the difficulties of using known devices and systems, solve the problems, and achieve the desired results described herein.

Claims (27)

Patent claims 1. Way to distinguish from multiple sheets. of a plurality of superimposed sheets, including (a) illuminating the first side of the sheet with a first radiation source located on the first side of the sheet, (b) detecting with a detector (146) located on the first side of the sheet (144) a first radiation level from the first radiation source (142) reflected from the first side of the sheet (144), (c) detecting by a detector (148) located on the other side of the sheet (144) a second radiation level from the first radiation source (142), passed through the sheet (144), (d) illuminating the other side of the sheet (144) with a second radiation source (152) positioned on the other side of the sheet (144), (e) detecting with a detector positioned on the other side of the sheet (144) ) a third level of radiation from the second radiation source (152) reflected from the second surface of the sheet (144), (f) is generated by the jumper (162) at most less one value based on the first level, the second level and the third level, and (g) comparing the at least one value with the at least one threshold value by means of a comparator (168), the relationship of the at least one value to the at least one the threshold value indicates whether the sheet (144) is a single or multiple sheet (144). 2. The method according to p. 1, incl. that eeap (c) uses a deekkor detecting the second radiation level being the same detector (148) that detects the third radiation level in step (e). 3. The method according to principles. 1, in that eeapy (b) and (cc) are performed on a first time interval and step (e) is performed on a second time interval. 4. The method according to principles. The method of claim 3, wherein the first interval and the second time interval are non-overlapping. 5. The method according to Zasł. 1, in that a sheet (144) having substantially non-uniform indicia printed on the first and second sides is rolled, and the method further includes the step of moving the sheet (144) along the path of the sheets through the detection area, the steps (a) - (e) is carried out each a plurality of times as the sheet (144) passes through the detection area. 6. The method according to p. The method of claim 5, further producing a first reflectance value in response to each of the plurality of first reflectance values detected during step (b), and combining the first plurality of reflectance values to produce a cumulative first reflectance value of the sheet. 7. The method according to principles. The method of claim 5, further generating a transmission value in response to each of the plurality of second levels generated during step (c), and combining the plurality of transmission factor values to form a cumulative transmission value of the sheet. 8. The method according to principles. The method of claim 6, further producing a transmission value c in response to each of the plurality of second levels generated during step (c), combining the plurality of transmission coefficient values to form a cumulative transmission value of the sheet (144), wherein in step (f) at least one weighting factor is applied to at least one total reflectance value and total transmittance value. 9. The method according to zasirz. 6. The process of claim 6, further generating a transmission value in response to each of the plurality of second levels generated during step (c), combining the plurality of transmission coefficient values to produce a total transmission value of the sheet (144) generating a second value. reflectivity in response to each of the plurality of third levels produced during step (e), and a plurality of second reflectance values are combined to produce a combined second reflectance value of the sheet (144). PL 197 470 B1 10. The method according to p. The method of claim 6, wherein in step (f) a weighting factor is applied to at least one of the first total reflectance value, the second total reflectance value, and total transmittance value. 11. The method according to p. 10, characterized by the following. that in step ((f) the weighting factor is applied such that increasing the first total reflectance value and / or the second total beat factor value serves to cause the relationship of at least one of these values and at least one threshold value to be compared in step ( g), tended to point to a multiple sheet. 12. The method according to p. 5, characterized by. that steps (b) and (c) are performed at each of the plurality of first periodic intervals, and step (e) is performed at a plurality of second periodic intervals, with the first periodic intervals not substantially overlapping the second periodic intervals. Method according to 1, characterized in that in et: apie ((f (ê at least one (one value is generated by applying at least one weighting factor to at least one output signal corresponding to at least one of the following levels: first, second, and / or the third. 14. The method according to 13, characterized by that the at least one weighting factor is applied such that an increase in the output signal corresponding to a first level increase and a third level increase changes the relationship towards pointing to the multiple sheet (144) in step (g). 15. The method according to principles The method of claim 1, wherein (as the first radiation source (14, 34, 142, 172) an infrared radiation source is used. 16. Method according to the above-mentioned (characterized in that the second radiation source (152, (74)) is an infrared radiation source. 17. The method according to p. The method of claim 1, further advancing the sheet (144) along a path of the sheets, and discharging the sheet (144) out of the path of the sheets under the relationship of said at least one value and at least one threshold value compared in step (g), indicating, that the sheet is a multiple sheet. 18. A device for distinguishing single sheets from multiple sheets, composed of a plurality of superimposed sheets, having a first radiation source located on the first side of the sheet path and a first detector, the radiation from the first radiation source being directed to strike the sheet in the pathway. sheets, characterized in that the first radiation source (14, 34, 142, 172) emits radiation substantially only during the first periodic intervals, and the first detector (20, 40 or 44, 146 or 148, 176 or 178) is positioned to examined radiation from a first radiation source (14, 34, 142, 172) that is either reflected or transmitted through a sheet (12, 114, 144, 179) through the sheets, the first detector (20, 40, 44, 146) , 148, 176, 178) is for generating the first signals when detecting the radiation, and the device has the first signal processing term (50, 156 or 158, 190 or 196) connected to functionally with the first signals, the first signal processing member (50, 156 or 158, 190 or 196) for generating a first output signal in response to first signals generated substantially only during the first periodic intervals, the scheduler (162) at in operative connection with the first output unit, the scheduler (162) acts in response to operation of at least the first output unit and generates a first detection value, and the comparator (168) in operative connection with the first unit (50, 156 or 158). 190 or 196) of signal processing, the comparator (168) being used to compare the first detected value and the threshold value, the relationship of the first detected value and the threshold value changing in response to the first output signal, and the relationship between the first detected value and the threshold value indicates whether the detected sheet is a single sheet or multiple. 19. Device according to principles. 18, characterized by. that it has a second detector (40 or 44, 146 or 148, 176 or 178) located on the opposite side of the sheet path from the first detector (40 or 44, 146 or 148, 176 or 178), which second detector (40 or 44, 146 or 148, 176 or 178) is positioned to study radiation from the first radiation source (14, 34, 142, 172) that is either reflected or transmitted through the sheet (12, 114, 144, 179) through the sheets the second detector (40 or 44, 146 or 148, 176 or 178) is used to generate the latter Upon detected radiation, and a second signal processing term (156 or 158, 190 or 196) operably coupled to the second signals, the second signal processing term (156 or 158, 190 or 196) for generating a second signal. the output signal in response to a portion of the second signals that is generated substantially only during the first periodic intervals, the second set of output signal being in operative connection with the comparator (168) and the relationship of the detected value and the threshold also changing in response to the second output signal. 20. The device according to claim 1 18, characterized in that the first signal processing member (50, 156 or 158, 190 or 196) comprises a first chopper circuit portion (80) that serves to amplify the first signals substantially only during the first periodic intervals and to suppress the first signals. substantially at all other times with the first portion (80) of the chopper circuit generating the first chopper signals. 21. Device according to principles. 20, characterized in that the first signal processing titer (50, 156 or 158, 190 or 196) comprises a first integrator circuit portion (90) that is to integrate the first chopper signals into a first period of time, the first portion (90) of the integrator circuit being (90) of the integrator circuit produces first integrator signals corresponding to a first output signal. 22. The device according to claim 22 21, further comprising a drive (122) to move the sheet along the sheet path (12, 114, 144, 179), the sheet (12, 114, 144, 179) extending through the sheet path between the first source (14). , 34, 142, 172) of radiation and either the first detector (20, 40 or 44, 146 or 148, 176 or 178) or the second detector (40 or 44, 146 or 148, 176 or 178) for at least part of the first period of time . 23. The device according to principles. 19, characterized by a sucker (162) operably connected to the first and second output groups, the scheduler (162) acting in response to the first and second output groups and generating the detected value. 24. Device according to principles. 23, characterized by. that further includes a data memory (130, 164) that includes data representing the weighting factors, and the stacker (162) is operatively coupled to the data memory (130, 164) to apply the weighting factors to the first and second outputs in creating the detected values. 25. An apparatus as claimed in 18, further comprising a processor (128, 166) that includes a comparator. The device of claim 26 The processor as claimed in claim 24, further comprising a processor (128, 166) in operative connection with a data memory (130, 164) in which data is stored, the processor (128, 166) comprising a staging member, the weighting factors applied to the the first and second outputs correspond to data stored in the data memory (130, 164). The device of claim 27 19. The apparatus of claim 19, further comprising a second radiation source (152, 174) positioned on the other side of the sheet path than the first radiation source (14, 34, 142, 172), the second side substantially opposite the first side, and the second radiation source (152, 174) emits radiation substantially only at second periodic intervals not corresponding to the first periodic intervals, the radiation from the second radiation source (152, 174) being directed to incident on the sheet (12, 114, 144, 179) on the sheet path, while the second detector (40 or 44, 146 or 148, 176 or 178) is located on the other side of the sheet path, and includes a third signal processing member (160, 192) in functional connection with the second signals, wherein the third signal processing term (160, 192) is for generating a third output signal in response to a portion of the second signals that is generated substantially only in the second periods. these intervals, and further, the third output signal group is operatively coupled to a comparator (168), wherein the relationship of the detected value to the threshold changes in response to the third output signal.