CA2261081C - Sensor for evaluating dielectric properties of specialized paper - Google Patents
Sensor for evaluating dielectric properties of specialized paper Download PDFInfo
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- CA2261081C CA2261081C CA002261081A CA2261081A CA2261081C CA 2261081 C CA2261081 C CA 2261081C CA 002261081 A CA002261081 A CA 002261081A CA 2261081 A CA2261081 A CA 2261081A CA 2261081 C CA2261081 C CA 2261081C
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- G—PHYSICS
- G07—CHECKING-DEVICES
- G07D—HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING
- G07D7/00—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency
- G07D7/02—Testing electrical properties of the materials thereof
- G07D7/026—Testing electrical properties of the materials thereof using capacitive sensors
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- General Physics & Mathematics (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
- Inspection Of Paper Currency And Valuable Securities (AREA)
Abstract
A capacitor sensor for assessing dielectric properties of currency paper uses a transmitting dielectrode on a first side of an evaluation channel and a receiving electrode on the same first side of the evaluation channel. A passive electrode is located on the opposite side of the evaluation channel and overlays with the transmitting and receiving electrodes. An electronic processing arrangement is connected to the transmitting and receiving electrodes and evaluates the signals for changes in the capacitance coupling of the electrode. This coupling is directly related to the properties of the paper passing between the passive electrode on one side and then transmitting and receiving electrodes on the other side.
Description
WH-10,294CA
TITLE: SENSOR FOR EVALUATING DIELECTRIC PROPERTIES OF
SPECIALIZED PAPER
FIELD OF THE INVENTION
The present invention relates to validators having sensors for evaluating dielectric properties of specialized papers. The invention has particular application for paper currency evaluation and security appear evaluation.
BACKGROUND OF THE INVENTION
Currency validators are designed to receive a banknote and move the banknote through an evaluator channel prior to accepting and storing of the accepted banknote.
From time to time a banknote can become jammed in the validator which creates problems, particularly for unsupervised installations.
Jamming of a validator often :Ls due to a wet or high humidity banknote or due to high density paper sometimes found in fraudulent banknotes. These conditions can be recognized by a capacitor sensor.
When the currency bill passes between capacitor electrodes, the capacitor capacitance increases according to the effect of the dielectric properties of the currency note. The deviations from this value will be observed when the samples with higher or lower density are tested in the validator.
Water has a dielectric constant almost ten times higher than the dielectric constant of currency paper.
V~lhen we, currency paper passes between the capacitor plates, its capacitance is higher than dry paper, the wetter the paper, the larger the capacitance (as compared to the authentic currency paper). Therefore, the capacitive sensor can determine the "humidity" of currency paper and can be used to evaluate the authenticity of the WH-10,294CA
paper, as the currency paper is being evaluated by the validator.
Many validators are used in a generally non-supervised application such as a vending machine.
Fraudulent bills often have a high density and if fully processed by a validator, can become jammed or damage the validator.
It is important in validators to reject fraudulent bills, however, it is also important to reject bills which may become jammed in the validator or which may damage the validator. A jammed validator causes the operator problems and also frustrates the user.
Information about the humidit~r and other parameters of the paper, evaluated by a validator, are important for the validator's operation.
The design of automatic validators makes contradictory demands. The size of the sensor should be small. It should be designed in such a way that it can be placed anywhere inside the validator channel. Rigid mechanical and electrical connections between the sensor elements placed on the opposite sides of the validator channel lead to complex configurations. The measurement results should not significantly vary with wobble of the paper in the validator channel. It is also desirable for the validator to reject bills which are likely to become jammed in the validator.
SUMMARY OF THE INVENTION
The present invention is directed to an arrangement for sensing the dielectric properties of a paper substrate as the paper substrate moves through an evaluation channel.
TITLE: SENSOR FOR EVALUATING DIELECTRIC PROPERTIES OF
SPECIALIZED PAPER
FIELD OF THE INVENTION
The present invention relates to validators having sensors for evaluating dielectric properties of specialized papers. The invention has particular application for paper currency evaluation and security appear evaluation.
BACKGROUND OF THE INVENTION
Currency validators are designed to receive a banknote and move the banknote through an evaluator channel prior to accepting and storing of the accepted banknote.
From time to time a banknote can become jammed in the validator which creates problems, particularly for unsupervised installations.
Jamming of a validator often :Ls due to a wet or high humidity banknote or due to high density paper sometimes found in fraudulent banknotes. These conditions can be recognized by a capacitor sensor.
When the currency bill passes between capacitor electrodes, the capacitor capacitance increases according to the effect of the dielectric properties of the currency note. The deviations from this value will be observed when the samples with higher or lower density are tested in the validator.
Water has a dielectric constant almost ten times higher than the dielectric constant of currency paper.
V~lhen we, currency paper passes between the capacitor plates, its capacitance is higher than dry paper, the wetter the paper, the larger the capacitance (as compared to the authentic currency paper). Therefore, the capacitive sensor can determine the "humidity" of currency paper and can be used to evaluate the authenticity of the WH-10,294CA
paper, as the currency paper is being evaluated by the validator.
Many validators are used in a generally non-supervised application such as a vending machine.
Fraudulent bills often have a high density and if fully processed by a validator, can become jammed or damage the validator.
It is important in validators to reject fraudulent bills, however, it is also important to reject bills which may become jammed in the validator or which may damage the validator. A jammed validator causes the operator problems and also frustrates the user.
Information about the humidit~r and other parameters of the paper, evaluated by a validator, are important for the validator's operation.
The design of automatic validators makes contradictory demands. The size of the sensor should be small. It should be designed in such a way that it can be placed anywhere inside the validator channel. Rigid mechanical and electrical connections between the sensor elements placed on the opposite sides of the validator channel lead to complex configurations. The measurement results should not significantly vary with wobble of the paper in the validator channel. It is also desirable for the validator to reject bills which are likely to become jammed in the validator.
SUMMARY OF THE INVENTION
The present invention is directed to an arrangement for sensing the dielectric properties of a paper substrate as the paper substrate moves through an evaluation channel.
- 2 -WH-10,294CA
The arrangement includes a generating electrode on a first side of the channel; a receiving electrode located on the first side of the channel and spaced from the generating electrode; a passive conducting electrode situated on a second side of the channel opposite the first side and overlapping with the generating electrode and the receiving electrode; and a electronic processing arrangement connected to the generating electrode and the receiving electrode which evaluates the signals thereof for changes in the detected capacitance sensed by coupling of the electrodes via the passive conducting electrode.
According to an aspect of the invention, the arrangement further includes a screening electrode located on the first side of the channel and connected to the electronic processing arrangement in a manner to diminish capacitance due to direct coupling of the generating electrode and the receiving electrode.
According to a further aspect of the invention, the generating electrode is provided with an alternating voltage high frequency signal.
According to yet a further aspect of the invention, the passive conducting electrode has no electrical connection with the electronic processing arrangement.
According to yet a further as~~ect of the invention, the processing arrangement converts any high frequency signal received by the receiving electrode into a d.c.
voltage which provides a measure of the capacitive coupling of the generating and receiving electrodes which is greatly changed in accordance with the banknote currency.
According to yet a further aspect of the invention, the electronic processing arrangement uses the d.c. voltage to assess the humidity of a substrate located in the evaluation channel.
The arrangement includes a generating electrode on a first side of the channel; a receiving electrode located on the first side of the channel and spaced from the generating electrode; a passive conducting electrode situated on a second side of the channel opposite the first side and overlapping with the generating electrode and the receiving electrode; and a electronic processing arrangement connected to the generating electrode and the receiving electrode which evaluates the signals thereof for changes in the detected capacitance sensed by coupling of the electrodes via the passive conducting electrode.
According to an aspect of the invention, the arrangement further includes a screening electrode located on the first side of the channel and connected to the electronic processing arrangement in a manner to diminish capacitance due to direct coupling of the generating electrode and the receiving electrode.
According to a further aspect of the invention, the generating electrode is provided with an alternating voltage high frequency signal.
According to yet a further aspect of the invention, the passive conducting electrode has no electrical connection with the electronic processing arrangement.
According to yet a further as~~ect of the invention, the processing arrangement converts any high frequency signal received by the receiving electrode into a d.c.
voltage which provides a measure of the capacitive coupling of the generating and receiving electrodes which is greatly changed in accordance with the banknote currency.
According to yet a further aspect of the invention, the electronic processing arrangement uses the d.c. voltage to assess the humidity of a substrate located in the evaluation channel.
- 3 -WH-10,294CA
The electronic processing arrangement in a preferred aspect of the invention uses a measurement of capacitance for determining the humidity of the substrate and rejects the substrate when the determined humidity is grater than a predetermined level. It also rejects dry fraudulent bills with deviations of the dielectric properties relative to known dielectric properties of authentic bills.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the _~nvention are shown in the drawings, wherein:
Figure 1 is a perspective view of the sensor electrode system, located in a validator evaluation channel;
Figure 2 is the block schemat:~c of the sensing arrangement; and Figure 3 is a schematic of thE~ arrangement for processing the signals of the sensing arrangement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Currency or banknote validato~_s move a banknote along a particular path and assuming the banknote is accepted, typically store the banknote in a stacking arrangement. The pathway through the validator has a number of sensors placed there along for evaluating the banknotes as it passes the sensor. Various drive wheels advance the banknote from the entrance to the validator to the banknote stacking arrangement. An example of such a validator is shown in our United States Patent 5,657,846.
A capacitive sensor 2, is shown in Figure 1 and is located in the channel 4 through which the banknote 7 is passed for evaluation in the direction of arrow 8. The channel 4 includes opposed channel walls 5 and 6 which are
The electronic processing arrangement in a preferred aspect of the invention uses a measurement of capacitance for determining the humidity of the substrate and rejects the substrate when the determined humidity is grater than a predetermined level. It also rejects dry fraudulent bills with deviations of the dielectric properties relative to known dielectric properties of authentic bills.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the _~nvention are shown in the drawings, wherein:
Figure 1 is a perspective view of the sensor electrode system, located in a validator evaluation channel;
Figure 2 is the block schemat:~c of the sensing arrangement; and Figure 3 is a schematic of thE~ arrangement for processing the signals of the sensing arrangement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Currency or banknote validato~_s move a banknote along a particular path and assuming the banknote is accepted, typically store the banknote in a stacking arrangement. The pathway through the validator has a number of sensors placed there along for evaluating the banknotes as it passes the sensor. Various drive wheels advance the banknote from the entrance to the validator to the banknote stacking arrangement. An example of such a validator is shown in our United States Patent 5,657,846.
A capacitive sensor 2, is shown in Figure 1 and is located in the channel 4 through which the banknote 7 is passed for evaluation in the direction of arrow 8. The channel 4 includes opposed channel walls 5 and 6 which are
- 4 -WH-10,294CA
made of a plastic or similar dielectric isolating material.
The channel walls 5 and 6 include slots therein for receiving the generator electrode 11 and the receiving electrode 12 as well as the screening electrode 14 in the channel wall 5. Directly opposite these electrodes is a large flat passive electrode 13 located in a slot in the channel wall 6. This flat passive electrode 13 is situated directly over and is parallel to the generator electrode 11 and the receiving electrode 12.
The passive electrode 13 is sized and placed within the channel walls 6 such that the projection of electrode 13 on the wall 5 of the channel covers both the generator electrode 11 and the receiving electrode 12. The purpose of the passive electrode is to couple the electrodes in a manner to be directly influenced by the change in capacitance caused by the dielectric properties of the banknote 7 passing between the electrodes.
The screening electrode 14 serves to reduce the direct coupling between the generating electrode 11 and receiving electrode 12.
As the banknote 7 is transpor~ed along the channel 4, it is located between the electrodes, and thus significantly effects the magnitude of the capacitive coupling of the electrodes. Generally, the banknote is parallel to electrodes 11, 12 and 13, however, it may be nonparallel because of some wobble on the banknote. The exact position of the banknote between the electrodes is not critical as the net is tolerable because capacitance is mainly dependent on the presence of the banknote between the electrodes and the exact location of the banknote between the electrodes is not as significant.
It can be appreciated the sen;~ing arrangement of Figure 1 is quite compact and rugged and there is no requirement to electrically hard wire the passive electrode
made of a plastic or similar dielectric isolating material.
The channel walls 5 and 6 include slots therein for receiving the generator electrode 11 and the receiving electrode 12 as well as the screening electrode 14 in the channel wall 5. Directly opposite these electrodes is a large flat passive electrode 13 located in a slot in the channel wall 6. This flat passive electrode 13 is situated directly over and is parallel to the generator electrode 11 and the receiving electrode 12.
The passive electrode 13 is sized and placed within the channel walls 6 such that the projection of electrode 13 on the wall 5 of the channel covers both the generator electrode 11 and the receiving electrode 12. The purpose of the passive electrode is to couple the electrodes in a manner to be directly influenced by the change in capacitance caused by the dielectric properties of the banknote 7 passing between the electrodes.
The screening electrode 14 serves to reduce the direct coupling between the generating electrode 11 and receiving electrode 12.
As the banknote 7 is transpor~ed along the channel 4, it is located between the electrodes, and thus significantly effects the magnitude of the capacitive coupling of the electrodes. Generally, the banknote is parallel to electrodes 11, 12 and 13, however, it may be nonparallel because of some wobble on the banknote. The exact position of the banknote between the electrodes is not critical as the net is tolerable because capacitance is mainly dependent on the presence of the banknote between the electrodes and the exact location of the banknote between the electrodes is not as significant.
It can be appreciated the sen;~ing arrangement of Figure 1 is quite compact and rugged and there is no requirement to electrically hard wire the passive electrode
- 5 -13 to the processing circuitry. This simplifies the electrical connection of the capacitance sensor as validators typically open by splitting along the pathway 4 for servicing of sensors and removing any banknote which may have become jammed. With a spilt validator, the components on one side of the pathway remain stationary and components on the opposite side of the pathway move when the validator is opened. In this case, the channel wall 5 can be located in the stationary part of the validator and thus, its electrical connection to the processing circuitry is simple and straightforward, and does not have to accommodate movement for service. The passive electrode 13 is located in the moving part of the housing.
In Figure 2, a high frequency generator 9 is connected with the generating electrode 11; the feed of the high frequency generator is also provided to the locking detector and is used as a reference signal. The receiving electrode 12 is connected with one of the differential inputs of the 20 lock-in detector 20. Another differential input of the lock-in detector 20 is supplied with the compensating high frequency signal formed by the capacitance divider C1-C2.
The screening electrode 14 is connected with the ground of the system. The signal formed by the lock-in detector 20 is amplified by amplifier 21 and is subsequently converted to a digital signal which may be analyzed by the program of the central processing unit 25. At certain levels of the signal, the banknote is rejected as having too high a moisture level, otherwise the signal is compared to the appropriate standard of authentic currency.
Figure 3 shows a schematic of the capacitance of the various electrodes of the sensor and the elements of the electronic processing arrangement that are directly as:~ociated with the electrodes. C11-12 is the capacitance between the generating electrode 11 and passive electrode 12; C13-12 is
In Figure 2, a high frequency generator 9 is connected with the generating electrode 11; the feed of the high frequency generator is also provided to the locking detector and is used as a reference signal. The receiving electrode 12 is connected with one of the differential inputs of the 20 lock-in detector 20. Another differential input of the lock-in detector 20 is supplied with the compensating high frequency signal formed by the capacitance divider C1-C2.
The screening electrode 14 is connected with the ground of the system. The signal formed by the lock-in detector 20 is amplified by amplifier 21 and is subsequently converted to a digital signal which may be analyzed by the program of the central processing unit 25. At certain levels of the signal, the banknote is rejected as having too high a moisture level, otherwise the signal is compared to the appropriate standard of authentic currency.
Figure 3 shows a schematic of the capacitance of the various electrodes of the sensor and the elements of the electronic processing arrangement that are directly as:~ociated with the electrodes. C11-12 is the capacitance between the generating electrode 11 and passive electrode 12; C13-12 is
-6-the capacitance between the passive electrode 13 and receiving electrode 12. As evident from Figure 1, these capacitance are the ones of plane capacitors. C11-12 is negligibly small in the case of installed screening electrode 14. Figure 3 also illustrates capacity divider C1, C2 for the signal of the high frequency generator 9, input capacitance C and input active resistances R of the inputs of the lock-in detector 20. It can be seen that the capacitors form a capacitance bridge with generator 9; the outputs of the bridge are connected to the inputs of the lock-in detector 20. The bridge may be balanced by adjusting capacitance divider C1, C2.
When the bridge is unbalanced, a d.c. voltage is produced at the output of the lock-in-detector 20. The resulting voltage is a direct function of the unbalanced state of the bridge.
Since the sensor has small plate sizes, the interelectrode capacitances are small, generally not exceeding 10 pF. The input capacitances of the lock-in detector are of the same order of magnitude. To achieve a useful sensitivity, a high generating frequency is used. It has been determined that the preferred frequency range is between 50 - 150 MHz.
At these frequencies, the impedances of the bridge capacitances are smaller than the input active resistances R
of lock-in detector and, therefore, the input resistances only marginally affect the phase and amplitude characteristics of the bridge.
It should be noted that the elements C1 and C2 can be excluded from the circuit if their absence does not saturate lock-in detector 20. In their absence, the system can be balanced by varying the input voltage shift of d.c. amplifier 21.
WH-10,294CA
V~hen the currency paper moves between the electrodes of the sensor, the capacit;~nces of C11-13 and C13-12 increase and unbalance the cap~~citance bridge. As the currency paper is situated in pra~~tically the constant field of the capacitors C11-13 and C13-12, the magnitude of the disbalance signal is isolated from effects of wobble the paper in the validator channel an~~ essentially depends on the dielectric properties of the currency paper. Thus by measuring the magnitude of the unbalanced signal, the system determines the authenticity of the dielectric properties of the currency paper.
Wet currency paper fed to the validator may jam the transport mechanism. Therefore, it is important to evaluate the moisture content of the currency paper as early as possible. The dielectric constant of water is approximately 10 times larger than the dielectric constant of dry currency paper. As such, currency paper having high humidity provides high capacitance and produces a large signal in the sensor. Thus, the magnitude of the output signals gives information about the humidity of the currency paper. If the measured signal is too high, the banknote is rejected.
It should be understood by those skilled in the art, that modifications may be made without departing from the spirit and scope of the invention as defined in the claims. Accordingly, reference should be made primarily to the accompanying claims, rather than the foregoing specification, to determine the scope of the invention.
_ g
When the bridge is unbalanced, a d.c. voltage is produced at the output of the lock-in-detector 20. The resulting voltage is a direct function of the unbalanced state of the bridge.
Since the sensor has small plate sizes, the interelectrode capacitances are small, generally not exceeding 10 pF. The input capacitances of the lock-in detector are of the same order of magnitude. To achieve a useful sensitivity, a high generating frequency is used. It has been determined that the preferred frequency range is between 50 - 150 MHz.
At these frequencies, the impedances of the bridge capacitances are smaller than the input active resistances R
of lock-in detector and, therefore, the input resistances only marginally affect the phase and amplitude characteristics of the bridge.
It should be noted that the elements C1 and C2 can be excluded from the circuit if their absence does not saturate lock-in detector 20. In their absence, the system can be balanced by varying the input voltage shift of d.c. amplifier 21.
WH-10,294CA
V~hen the currency paper moves between the electrodes of the sensor, the capacit;~nces of C11-13 and C13-12 increase and unbalance the cap~~citance bridge. As the currency paper is situated in pra~~tically the constant field of the capacitors C11-13 and C13-12, the magnitude of the disbalance signal is isolated from effects of wobble the paper in the validator channel an~~ essentially depends on the dielectric properties of the currency paper. Thus by measuring the magnitude of the unbalanced signal, the system determines the authenticity of the dielectric properties of the currency paper.
Wet currency paper fed to the validator may jam the transport mechanism. Therefore, it is important to evaluate the moisture content of the currency paper as early as possible. The dielectric constant of water is approximately 10 times larger than the dielectric constant of dry currency paper. As such, currency paper having high humidity provides high capacitance and produces a large signal in the sensor. Thus, the magnitude of the output signals gives information about the humidity of the currency paper. If the measured signal is too high, the banknote is rejected.
It should be understood by those skilled in the art, that modifications may be made without departing from the spirit and scope of the invention as defined in the claims. Accordingly, reference should be made primarily to the accompanying claims, rather than the foregoing specification, to determine the scope of the invention.
_ g
Claims (19)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A system for sensing dielectric properties of currency paper, said system comprising an evaluation channel through which the currency paper moves; said evaluation channel including on one side of said evaluation channel a) a generator producing a high frequency signal connected to a generating electrode;
b) a receiving conducting electrode situated a spaced distance from the generator electrode in generally the same plane thereof; said evaluation channel on an opposite side including c) a passive conducting electrode situated in a plane, parallel to the plane of the generating electrode and receiving electrode and having a capacitance coupling therewith; said system further including d) a signal processing arrangement connected with the generating and the receiving electrodes and converting a high frequency signal on the receiving electrode with reference to the high frequency signal of said generating electrode into a d.c. voltage that characterizes a magnitude of capacitance coupling between the generator and receiving electrodes, the magnitude of the d.c. voltage being dependent on humidity and dielectric properties of the currency paper moving through the evaluation channel between the electrodes.
b) a receiving conducting electrode situated a spaced distance from the generator electrode in generally the same plane thereof; said evaluation channel on an opposite side including c) a passive conducting electrode situated in a plane, parallel to the plane of the generating electrode and receiving electrode and having a capacitance coupling therewith; said system further including d) a signal processing arrangement connected with the generating and the receiving electrodes and converting a high frequency signal on the receiving electrode with reference to the high frequency signal of said generating electrode into a d.c. voltage that characterizes a magnitude of capacitance coupling between the generator and receiving electrodes, the magnitude of the d.c. voltage being dependent on humidity and dielectric properties of the currency paper moving through the evaluation channel between the electrodes.
2. The system of claim 1, further comprising a screening electrode, situated between the generating electrode and receiving electrode connected to the signal processing arrangement, said screening electrode diminishing the direct capacitance between generating and receiving electrodes.
3. The system of claim 1, wherein a lock-in detector is used for the transformation of high frequency voltage of the receiving electrode.
4. The system of claim 3, wherein an attenuated output of the generator is applied to a differential input of said lock-in detector and is used as a compensation signal when there is no currency paper in the space between the electrodes.
5. The system of claim 1, wherein the signal processing arrangement is situated near the generator and receiving electrodes which are all situated on one side of a channel which receives the currency paper.
6. An arrangement for sensing the dielectric properties of a paper substrate as the paper substrate moves through an evaluation channel, said arrangement comprising;
a generating electrode on a first side of said channel connected to a high frequency signal source;
a receiving electrode located on said first side of said channel and spaced from said generating electrode;
a passive conducting electrode situated on a second side of said channel opposite said first side and overlapping with said generating electrode and said receiving electrode;
and a electronic processing arrangement connected to said generating electrode and said receiving electrode which evaluates the signals thereof for changes in the capacitance couplings of said electrodes via the passive conducting electrode.
a generating electrode on a first side of said channel connected to a high frequency signal source;
a receiving electrode located on said first side of said channel and spaced from said generating electrode;
a passive conducting electrode situated on a second side of said channel opposite said first side and overlapping with said generating electrode and said receiving electrode;
and a electronic processing arrangement connected to said generating electrode and said receiving electrode which evaluates the signals thereof for changes in the capacitance couplings of said electrodes via the passive conducting electrode.
7. An arrangement as claimed in claim 6 wherein said arrangement further includes a screening electrode located on said first side of said channel between said generating and receiving electrodes and connected to said electronic processing arrangement in a manner to diminish direct capacitance between said generating electrode and said receiving electrode.
8. An arrangement as claimed in claim 7 wherein said generating electrode is provided with an alternating voltage high frequency signal having a frequency in the range of 50 to 150 MHz.
9. An arrangement as claimed in claim 6 wherein said generating and said receiving electrodes are located in the same plane and said evaluation channel is made of a dielectric isolating material.
10. An arrangement as claimed in claim 9 wherein said passive electrode has no direct electrical connection with said electronic processes arrangement.
11. An arrangement as claimed in claim 9 wherein said electronic processing arrangement converts any high frequency signal received by said receiving electrode into a d.c.
voltage which provides a measure of the capacitance coupling between said generating and receiving electrode via the passive electrode.
voltage which provides a measure of the capacitance coupling between said generating and receiving electrode via the passive electrode.
12. An arrangement as claimed in claim 11 wherein said electronic processing arrangement uses the d.c. voltage to additionally assess the humidity of said paper substrate.
13. An arrangement as claimed in claim 12 wherein said electronic processing arrangement uses a measurement of capacitance for determining the humidity of the substrate and rejecting the substrate when the determined humidity is greater than a predetermined level.
14. An arrangement as claimed in claim 6 wherein said passive electrode is at least twice the size of said generating electrode.
15. A system for sensing dielectric properties of currency paper, said system comprising:
a) a generator producing a high frequency signal connected to a generating electrode;
b) a receiving conducting electrode situated a spaced distance from the generator electrode in generally the same plane thereof;
c) a passive conducting electrode situated in a plane, parallel to the plane of the generating electrode and receiving electrode and defining a currency evaluation channel with said passive conducting electrode on one side of said channel and said generating and receiving electrodes on an opposite side of said channel, said passive conducting electrode having no electrical interconnections with a signal processing arrangement; and d) said signal processing arrangement being connected with the generating and the receiving electrode and converting a high frequency signal on the receiving electrode with reference to the high frequency signal of said generating electrode into a d.c. voltage that characterizes the magnitude of capacitance coupling between the generator and receiving electrodes, the magnitude of the d.c. voltage being dependent on the humidity and dielectric properties of the currency paper placed in the space between the electrodes.
a) a generator producing a high frequency signal connected to a generating electrode;
b) a receiving conducting electrode situated a spaced distance from the generator electrode in generally the same plane thereof;
c) a passive conducting electrode situated in a plane, parallel to the plane of the generating electrode and receiving electrode and defining a currency evaluation channel with said passive conducting electrode on one side of said channel and said generating and receiving electrodes on an opposite side of said channel, said passive conducting electrode having no electrical interconnections with a signal processing arrangement; and d) said signal processing arrangement being connected with the generating and the receiving electrode and converting a high frequency signal on the receiving electrode with reference to the high frequency signal of said generating electrode into a d.c. voltage that characterizes the magnitude of capacitance coupling between the generator and receiving electrodes, the magnitude of the d.c. voltage being dependent on the humidity and dielectric properties of the currency paper placed in the space between the electrodes.
16. The system of claim 15, further comprising a screening electrode, situated between the generating electrode and receiving electrode connected to the signal processing arrangement, said screening electrode diminishing the direct capacitance between generating and receiving electrodes.
17. The system of claim 15, wherein a lock-in detector is used for converting of high frequency voltage of the receiving electrode.
18. The system of claim 17, wherein a attenuated output of the generator being applied to a differential input of said lock-in detector and is used as a compensation signal when there is no currency paper in the space between the electrodes.
19. The system of claim 15, wherein the signal processing arrangement is situated near the generator and receiving electrodes which are all situated on one side of a channel which receives the currency paper.
Priority Applications (10)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002261081A CA2261081C (en) | 1999-02-01 | 1999-02-01 | Sensor for evaluating dielectric properties of specialized paper |
| AU25062/99A AU772710B2 (en) | 1999-02-01 | 1999-02-17 | Sensor for evaluating dielectric properties of specialized paper |
| CNB998159808A CN1187719C (en) | 1999-02-01 | 1999-02-17 | Sensor for evaluating dielectric properties of specialized paper |
| ES99904649T ES2214008T3 (en) | 1999-02-01 | 1999-02-17 | SENSOR TO EVALUATE THE DIELECTRIC PROPERTIES OF PAPERS WITH SPECIFIC USES. |
| BR9917015-9A BR9917015A (en) | 1999-02-01 | 1999-02-17 | System for sensing dielectric properties of paper money, and, arrangement for sensing the dielectric properties of a paper substrate |
| DE69914107T DE69914107T2 (en) | 1999-02-01 | 1999-02-17 | SENSOR FOR EVALUATING THE DIELECTRICAL PROPERTIES OF SPECIAL PAPER |
| JP2000597764A JP2002536751A (en) | 1999-02-01 | 1999-02-17 | Sensor for evaluating the dielectric properties of special paper |
| EP99904649A EP1149363B1 (en) | 1999-02-01 | 1999-02-17 | Sensor for evaluating dielectric properties of specialized paper |
| PCT/CA1999/000117 WO2000046760A1 (en) | 1999-02-01 | 1999-02-17 | Sensor for evaluating dielectric properties of specialized paper |
| US09/263,516 US6229317B1 (en) | 1999-02-01 | 1999-03-05 | Sensor for evaluating dielectric properties of specialized paper |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002261081A CA2261081C (en) | 1999-02-01 | 1999-02-01 | Sensor for evaluating dielectric properties of specialized paper |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2261081A1 CA2261081A1 (en) | 2000-08-01 |
| CA2261081C true CA2261081C (en) | 2006-05-09 |
Family
ID=4163261
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002261081A Expired - Fee Related CA2261081C (en) | 1999-02-01 | 1999-02-01 | Sensor for evaluating dielectric properties of specialized paper |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP1149363B1 (en) |
| JP (1) | JP2002536751A (en) |
| CN (1) | CN1187719C (en) |
| AU (1) | AU772710B2 (en) |
| BR (1) | BR9917015A (en) |
| CA (1) | CA2261081C (en) |
| DE (1) | DE69914107T2 (en) |
| ES (1) | ES2214008T3 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4599566B2 (en) | 2004-08-31 | 2010-12-15 | 国立大学法人 新潟大学 | Electrical detection of nonpolar complex molecular motion using inhomogeneous electric fields |
| JP4622694B2 (en) * | 2005-06-16 | 2011-02-02 | 富士電機リテイルシステムズ株式会社 | Bill recognition device |
| DE102013205048A1 (en) * | 2013-03-21 | 2014-09-25 | Bundesdruckerei Gmbh | Device and method for authenticating a value or security document |
| JPWO2015029904A1 (en) * | 2013-09-02 | 2017-03-02 | アルプス電気株式会社 | Moisture detector |
| KR101554253B1 (en) | 2013-12-20 | 2015-09-18 | 노틸러스효성 주식회사 | An apparatus for detecting wet-notes in ATM and the detection method thereof |
| CN104049003A (en) * | 2014-06-10 | 2014-09-17 | 中国人民银行印制科学技术研究所 | Array-capacitor inductive sensor and negotiable-securities anti-counterfeit detection method |
| CN107393116B (en) * | 2017-07-06 | 2023-04-25 | 得力集团有限公司 | Cash inspecting machine and cash inspecting method and circuit structure thereof |
| JP2019120582A (en) * | 2018-01-05 | 2019-07-22 | 株式会社リコー | Characteristic detection device, media supply device, and image forming device |
| CN109345685A (en) * | 2018-11-09 | 2019-02-15 | 威海华菱光电股份有限公司 | Paper product discrimination method and device and storage medium |
| JP6873338B2 (en) * | 2018-12-05 | 2021-05-19 | 三菱電機株式会社 | Capacitance detector and image reader |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4355300A (en) * | 1980-02-14 | 1982-10-19 | Coulter Systems Corporation | Indicia recognition apparatus |
| NO165697C (en) * | 1988-03-10 | 1991-03-20 | Inter Marketing Oy Ab | SENSOR FOR AUTHENTICITY OF SECURITY PAPER. |
| DE4232185A1 (en) * | 1992-09-25 | 1994-03-31 | Chemnitz Textiltech Forsch | Residual humidity measurement for moving material web - using screening effect on generated electrical field to determine humidity-dependent DC resistance of web |
-
1999
- 1999-02-01 CA CA002261081A patent/CA2261081C/en not_active Expired - Fee Related
- 1999-02-17 AU AU25062/99A patent/AU772710B2/en not_active Ceased
- 1999-02-17 BR BR9917015-9A patent/BR9917015A/en not_active IP Right Cessation
- 1999-02-17 EP EP99904649A patent/EP1149363B1/en not_active Expired - Lifetime
- 1999-02-17 JP JP2000597764A patent/JP2002536751A/en active Pending
- 1999-02-17 DE DE69914107T patent/DE69914107T2/en not_active Expired - Lifetime
- 1999-02-17 ES ES99904649T patent/ES2214008T3/en not_active Expired - Lifetime
- 1999-02-17 CN CNB998159808A patent/CN1187719C/en not_active Expired - Fee Related
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|---|---|
| CN1187719C (en) | 2005-02-02 |
| AU772710B2 (en) | 2004-05-06 |
| EP1149363B1 (en) | 2004-01-07 |
| ES2214008T3 (en) | 2004-09-01 |
| JP2002536751A (en) | 2002-10-29 |
| CA2261081A1 (en) | 2000-08-01 |
| CN1348573A (en) | 2002-05-08 |
| BR9917015A (en) | 2002-01-15 |
| DE69914107D1 (en) | 2004-02-12 |
| EP1149363A1 (en) | 2001-10-31 |
| DE69914107T2 (en) | 2004-10-21 |
| AU2506299A (en) | 2000-08-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |
Effective date: 20140203 |