RU2388141C2 - Automatic batcher - Google Patents

Abstract

FIELD: physics; control.

SUBSTANCE: invention relates to automation. The automatic batcher for pieces of paper for use as hand wipers has an infrared sensor system for user detection. The sensor system scans at a first scanning frequency, as well as at a second higher frequency. When the sensor system detects a user, it changes the scanning frequency from the first to the second.

EFFECT: reduced power consumption, as well as fast reaction for issuing out paper.

34 cl, 8 dwg

Description

FIELD OF THE INVENTION

The present invention generally relates to a dispenser, in particular, of a type comprising a dosed tempering system driven by an electric motor combined with a control circuit for recognizing the presence of a potential user and controlling the operation of said electric motor for dispensing dosed material. Moreover, the invention, even more precisely, relates to an automatic towel dispenser (preferably paper towels stored inside the dispenser body) with an electric drive (in particular, operating from a battery, but may also be an alternating current (AC) power supply or a combination of power alternating current and direct current (DC)), in which paper sheets, such as paper towels for hands, are dispensed when the presence of said potential user is detected satisfying the condition of being within the range hydrochloric zone, without physical contact the user with the dispenser required to actuate the dispensing sequence. Such dispensers are often referred to as dispensers that do not require manual manipulation or contactless dispensers.

BACKGROUND OF THE INVENTION

Dispensers of the aforementioned type are known, for example, from US-A1-2003 / 0169046 and US-B1-6695246, as well as US-A-60G9354.

For example, in a dispenser according to US-B1-6695246, the sensitive control circuitry uses either passive infrared radiation, that is, detection of reflected external infrared radiation, or active infrared radiation (both emitting and detecting infrared radiation) to control presence detection possible user. In the active IR mode, the presence of an object (that is, a possible user) can be detected within the detection zone from about 12 to 24 cm at the dispenser and, according to the mentioned detection, the motor is controlled to dispense a hand towel to the user. The detection zone is kept small so that objects that are outside the detection zone do not lead to undesirable or unintended dosing. When in the desired area, the microprocessor controlling the operation of the electric motor drives the electric motor to dispense the towel only when two scanning cycles are received by the infrared radiation sensing circuit. The microprocessor can be driven to scan at approximately 7 Hz (i.e., 1 scan cycle every 0.14 seconds) by using a vibrator to turn the microprocessor on and off. Alternatively, it can be tuned to operate at a different frequency. When the electric motor is running, the microprocessor remains constantly on.

US-A1-0169046 discloses a dispenser in which an IR sensor system is mentioned as an alternative to capacitive detection for near detection. In the example of capacitive type identification, a capacitive type sensor is connected to the microprocessor. No details are given as to where the IR sensor system would be located, if any, nor how it would be arranged for operation. An additional sensor system is included in the composition for detecting paper web in the exhaust chute. The optional paper sensing system uses a microprocessor to feed power on / off pulses to the photosensors. Additionally, a watchdog timer can be used that stops the pulse function and resumes it again when it periodically puts the microprocessor from the idle state into an active state.

US-A-6069354 discloses a meter using active infrared radiation that produces a square wave at approximately 1.2 kHz so as to emit a modulated infrared signal that is detected according to reflection from a possible user on the infrared detector. This document assumes the use of a sensor system configured to recognize a user that is between approximately 1.25 cm and approximately 30 cm from the dispenser.

The above documents all use sensory systems that, when operational, operate at a specific scanning frequency (repetition frequency) to drive an electric motor to dispense a piece of towel.

The above dispensers operate using a scanning frequency (number of scan cycles per second) that is constant when the device is operational. This frequency remains fairly high, so that when the user is in the detection zone, the dispenser will not be too slow for dispensing. A high scanning frequency, however, means that energy is consumed at a high level, since infrared emitters and detectors need to be activated very often, and those that consume energy when they are active. Using a lower scanning frequency would, of course, save energy, but the time for dispensing a towel, in this case, could be longer, and when the user quickly moves his / her hands to the dispenser after washing, this may give the user the feeling that the device is not detecting him / her properly if the towel is not dispensed immediately.

The present invention has as one of its objectives the provision of low power consumption by the sensor system during periods when a potential / potential user (i.e., an object intended by a user requiring dosing of an article, such as a piece of hand towel or toilet paper) is not located close enough to the dispenser and at the same time providing a relatively quick reaction time when the potential / potential user is close enough to the dispenser and needs a towel to be dispensed. Low power consumption is especially important in batchers that are fully battery-powered, from one or more replaceable batteries, especially those battery systems that operate without the possibility of recharging with a solar recharge system or another type of recharge system, while batchers of this type are intended working for a long time (for example, enough time to dispense 60 or more rolls of paper without requiring battery replacement).

An additional objective of the invention is, in addition, to provide the possibility of additional energy savings when there are no possible users in the vicinity of the dispenser.

In addition, additional objectives of the invention will be apparent from reading this description of the invention.

SUMMARY OF THE INVENTION

The main objective of the invention is achieved by providing a dispenser having the features defined in paragraph 1 of the claims. Some preferred features of the invention are defined in the dependent claims.

Additional preferred features of the invention will be apparent to the reader of this description of the invention.

The invention is based on the concept that the scanning frequency, that is, the number of scanning cycles performed per second, is provided to be varied depending on the user's location relative to the dispenser, so that the dispenser operates at the first scanning frequency (i.e., performs a scan sequence by activating the circuits IR emitter and receiver and emitting single scan pulses in the first number of single scan cycles per second) when no possible o / potential user. The system then increases the scanning frequency when a user logs in close to the dispenser (i.e., enters the first detection zone). This variable scanning frequency makes it possible to use very low power when no users are close enough to the dispenser and use a higher power level only when required, so that the user experiences a fast reaction time to dispense the product.

The invention thus provides a sensor system that creates a first detection zone, which, when a potential user enters, initiates a change in the scanning frequency from the first lower scanning frequency to the second higher scanning frequency.

The first detection zone may be resized in order to detect the user at varying distances. For example, a remote sensor connected either with a wired connection to the dispenser or a wireless line (e.g., IR or radio) with the dispenser can be used to detect a user entering the toilet room, and thus can initiate a change in the first scan frequency to the second scan frequency . Such a “remote” sensor could, if required, alternatively be mounted on the front facing of the dispenser and can be configured to operate at a very low scanning frequency due to the distance of the entrance to the toilet room from the location of the dispenser, so that the time when a potential user wants to use the dispenser and, accordingly, moved closer to the dispenser, the dispenser was already working at a higher second scanning frequency, which allows s rapid detection of active IR sensor system of the dispenser defined in the claims.

Alternatively, the same set of sensors that are used to prompt the dispenser to dispense the product can also be used to detect a user entering the first detection zone and to incorporate a control system that changes the scan frequency from the first lower scan frequency to second higher scan rate. In this way, a user who is suitable for the dispenser (for example, 40 to 50 cm or maybe even further from the dispenser) will actuate the sensor system to change the scanning frequency to a higher scanning frequency, and, as the user continues to move his hands and / or body closer to the outlet of the dispenser, the user will be detected as being in the "dispensing zone" and, accordingly, force the dispenser to dispense the product (for example, a paper towel for hands).

If required, more than two scan frequencies can be used. For example, you can use the first slow scan frequency (such as 1 or 2 times per second), followed by a higher second scan frequency (for example, from 3 to 6 times per second), followed by an additional higher frequency (for example, from 7 to 12 times per second), whereby the scanning frequency changes from one frequency to the next, as the user is detected moving closer to the dispenser. This can be accomplished, for example, by a sequence of different sensors, each of which detects at different distances, or, for example, by using the same set of sensors to detect increased reflection of the infrared signal from the user as the user comes closer to the dispenser.

When the user moves away from the dispenser, the scanning frequency, in this case, can again be reduced to a lower frequency, thereby consuming less energy for the sensors.

As will be apparent, even at relatively short distances for the first detection zone (for example, up to about 50 cm from the dispenser, for example, in a direction from 30 ° to 60 ° inclined forward and downward), it will be understood that the system has the additional advantages of significant energy savings still, along with the possibility of a good reaction time for dispensing towels. This is because the user suggests that his / her hands should be moved relatively close to the device in order to dispense, and this takes about a quarter and a half seconds at normal hand movement speeds (between 0.2 m / s and 0 , 5 m / s), by that time the dispenser can already be made scanning at a second higher frequency (or even even higher frequency) and thus able to dispense very close to the point in time when the hands are in the “assumed” position and dosing (ie, a position where a user might be expected to dispense a towel, typically, public anything from 15 to 25 cm from the outlet of the dispenser).

Similarly, it is preferable that, when using the IR sensor system, the sensor system should preferably be able to cope with the exceptional anomalies of short-term high-IR reflections that sometimes occur without dispensing the towel, so that it is suitable for two or more following each other one after another scan cycles or, for example, a predetermined number of scan cycles for a certain number of successive cycles kanirovaniya (e.g., two out of three consecutive scans), each exists at a predetermined level of IR above background level of IR radiation prior to dispensing the product.

An advantageous use may consist of a varying scan frequency by setting a first scan frequency, for example between 0.15 and 0.25 seconds between scan cycles (i.e., scan frequency when a potential user is outside the first detection zone) or even longer (such as between 0 , 25 seconds and 0.5 seconds), and a second scan frequency, of the order of about 0.08 to 0.12 seconds, between scan cycles, and the requirements of only two consecutive scan cycles (or For example, two of three consecutive scans) providing the level of the reflected IR level above background IR radiation, for actuating the dispensing action. Such dosing will be perceived by the user as almost immediate, however, a significant amount of energy used by the sensor system can be saved due to the low initial scanning frequency, which consumes less energy.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further explained in more detail with reference to some non-limiting options for its implementation and using the accompanying drawings, in which:

figure 1 shows a schematic front view of a dispenser of paper towels with a roll of paper and a paper transport mechanism in a hidden form, depicting a schematic view of the first detection zone,

figure 2 shows a side view of the layout of figure 1, in accordance with which the side panel of the dispenser was removed to schematically show the paper roll and simplified schematic details of the paper transport mechanism,

figure 3 shows an additional embodiment of the invention with an additional sensor capable of detecting a user at a remote distance from the dispenser,

figure 4 shows an exemplary graph of the amplitude of the emissivity of the scanning pulses as a function of time,

figure 5 shows a graph of the level of the received signal versus time for a sequence of received reflections of infrared radiation resulting from the emitted pulses of infrared radiation in figure 4,

6 shows a schematic representation of the main elements of a system according to an embodiment of a dispenser according to the invention,

Fig. 7 shows an RC circuit used to make an active state of a microprocessor in an MCU in order to perform a scan cycle, and

FIG. 8 shows an alternative embodiment of the RC circuit shown in FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figures 1 and 2 show the dispenser 1 in front and side views, respectively, in accordance with which Fig. 2 shows the dispenser 1 mounted on its rear side to the wall (the mounting means are not shown, but can be of any suitable type, such as screws, glue, adhesive tape or other means of fastening).

The dispenser 1 comprises a housing 2 within which the product stock is located, in this case the paper stock in the roll 3. The roll is respectively a roll of continuous unperforated paper, but may also contain perforated paper in some cases. Also located in the housing 2 is a paper transport mechanism 4, preferably in the form of a modular drive cassette with its own casing 15, which can preferably be removed as a single unit from the housing 2 when the housing is open.

Figure 1 shows a roll of paper 3 and a transport mechanism 4 as simple blocks for the sake of simplicity. Similarly, FIG. 2 shows a paper roll 3 and a conveying mechanism 4 in a very simplified form, whereby the conveying mechanism includes a drive roller 5 engaged with a support roller 6, whereby a portion of the paper sheet 7 is shown located between said rollers 5, 6 with a leading edge of said paper sheet 7, ready for dispensing, in an outlet 8 formed in the housing 2 on its lower side.

The drive roller 5 is schematically shown attached to a drive motor M powered by batteries B. A gear train, typically in a gearbox, can be connected between the drive shaft of the electric motor and drive roller 5. Suitable batteries may supply 6V when new, and typically four batteries in 1.5 V are suitable for this purpose. Examples of suitable types are MN1300 Duracell batteries, whereby each battery has a capacity of 13A · h and can operate from fully charged to fully discharged in the range from 1.5V to 0.8V. The operation of the electric motor M causes the drive roller 5 to rotate and therefore pull the paper sheet 7 from the paper roll 3 by pinching the paper in the contact area of the rollers 5 and 6. When driven, the electric motor rotates, thereby removing the paper sheet from the roll 3, which also rotates in order to allow the paper to move toward the outlet 8. Other types of drive mechanisms for removing paper from the roll may also be used. Details of the paper transport mechanism or other product transport mechanism, however, are not important for understanding the invention. Such devices are also well known in the art per se.

It will also be a priori clear that the drive roller 5 and the support roller 6 can have their functions mutually rearranged, so that the support roller 6 would be a drive roller that is operably connected to the drive motor (and thus the drive roller 5 shown in FIG. .2, acts only as a backup roller in contact with the roller 6, usually with paper or a towel in the contact zone between them).

Although the principle of operation is explained using paper in the form of a continuous paper sheet in a roll, it should be clear that the dispenser can be used to dispense other products from the stock of products, for example, such as a continuous piece of paper in the form of an accordion. Alternative products can be dispensed by the device when properly redesigned. It is also possible that other metering devices may function with a metering device. For example, the dispenser may further include an air freshener that is activated, for example, every 5 or 10 minutes (or another suitable time) or once after a certain number of dispensed towels. This dispenser with additional features may be controlled by a dispenser control circuit (to be described later) or by a separate control circuit (not described herein).

The electric motor M is at rest and without energy supplied to it, when the paper should not be dosed at all. The electric motor M rotates when the paper is to be dosed through the outlet 8. The operation of the electric motor M is controlled by a main control device (not shown in FIGS. 1 and 2, but described later) connected to a sensor system containing sensing elements 9-13, of which sensitive elements 10 and 12 are emitters, preferably IR emitters, and sensitive elements 9, 11 and 13 are IR receivers. Such IR emitters and receivers are well known in the art and typically contain diode structures. Suitable IR emitters and receivers, for example, are manufactured by Lite-ON Electronics Inc. under the type number LTE-3279K for IR emitters and under the type number LTR-323DB for receivers. Other types of IR emitters and receivers, of course, can also be used. In the shown embodiment, the sensitive elements: IR emitters 10, 12 and IR receivers 9, 11, 13, are shown distributed at approximately equal intervals continuously in the transverse direction X-X of the housing (generally parallel to the roll 3 of storage products). The interval may suitably be an interval of about 5 cm between the next emitter and the receiver, so that the distance between the sensing elements 9 and 10, 10 and 11, 11 and 12, 12 and 13 are all approximately equal.

In addition, emitters and receivers are shown (see FIG. 2) arranged on opposite sides of the outlet 8. Other arrangements of the sensing elements are also possible, such as where all the sensing elements are placed on the front side of the outlet in a straight row (i.e., in where the sensors 10 and 12 are shown placed in figure 2). Sensing elements could also be placed on the rear side of the outlet in a straight row (for example, where sensitive elements 9, 11 and 13 are shown placed). The arrangement of the sensing elements in series, in the order of the receiver / emitter / receiver / emitter / receiver, enables the predominant form of the detection zone, which, in shape, is somewhat similar to the language (see figure 1). The underlying form of the tongue can vary to some extent, for example, depending on the power applied to the emitters, as well as their relative degree of protrusion from their housing.

Dispenser 1 upon detection of a possible user (the sequence of detection operations is described further below) without any contact of the user with the dispenser or sensitive elements for a sufficient time in the first detection zone thus forces the dispenser to determine that the user is present in the dispensing zone and, accordingly dispense the product. Dosing, in this case, is carried out with the front portion of the paper 7, released automatically. This allows the user to grab the paper 7 and pull it toward the cutting edge, such as the cutting edge 16 shown in FIG. 2, close to the outlet 8, so as to remove a torn / cut piece of paper. The location of the cutting edge, of course, can be changed, for example, to be at or up to 1 cm lower and opposite to the roller 5.

The first detection zone 14, as shown in FIGS. 1 and 2, is shown to be somewhat tongue-like and tilted down and forward from the outlet at an angle of x °, preferably between 20 ° to 30 ° relative to the vertical axis Y, for example 27, 5 °. As will be explained in more detail below, when a potential user’s body part enters this first detection zone 14, the sensor system detects the presence of the user and causes the sensor system to change from the first scanning frequency to a second scanning frequency that is higher than the first scanning frequency. The sensor system, in this case, also causes the motor M to rotate when judged by the user (due to the received signals) as being present in the dosing zone. The definition of a user in a position requiring towel dispensing is explained below.

Although the preferred arrangement of the emitters / receivers is advantageous, the use of only one emitter and one receiver or more than 2 emitters and 3 receivers can also be used. The configuration or field covered by the sensing elements, however, will change accordingly, and 2 emitters and three sensing elements were found to be advantageous in the balance between the obtained coverage area and the required energy consumption.

In the alternative embodiment of the invention shown in FIG. 3, an additional sensing element 19, removed from the dispenser housing 2 and, when operating, is connected by a wireless or wire connection 20 to the sensor system (schematically shown under 22) and its control system in the dispenser housing, can be used to form the first detection zone 18, which is further from the dispenser than the detection zone 17 (the detection zone 17 in this case is similar in shape to the first detection zone 14 in FIGS. 1 and 2). Alternatively or additionally, the additional sensing element can be placed on the front of, for example, the front surface, the dispenser housing and be facing in the direction of travel from any wall or the like on which the dispenser is mounted to allow a longer detection range in front of the dispenser, such as a sensor element 21 shown schematically, which is also connected to the sensor system 22. The sensor element 19 and / or 21, for example, can be configured to detect detect the presence of possible users up to a distance greater than the first detection zone, for example a distance of more than 50 cm, preferably more than 100 cm, more preferably more than 200 cm, and even more preferably more than 300 cm, or even further from the housing 2 dispensers.

The emitters 10, 12 of the sensor system are arranged using a suitable control circuit that can control the circuit, as is essentially known in the art, to emit pulsed infrared radiation in a narrow frequency band of approximately 15 kHz. However, a different infrared frequency could be chosen. The receivers (sensing elements) 9, 11, 13 are configured to detect the emitted infrared radiation, which is reflected from objects (fixed or moving) back to the receivers. In order to detect infrared radiation, which originates mainly and almost completely from the emitted infrared radiation, even up to very bright conditions (10,000 lux or more), it is preferable from all sources and frequencies of infrared radiation due to background influences , IR receivers need to tune to the frequency of the emitters. Thus, IR receivers are equipped with a detection circuit that suppresses IR radiation outside the expected frequency range of the reflected waves and amplifies IR radiation at a level of the 15 kHz range. In this regard, despite the fact that the frequency detection range is both higher and lower than the range of the emitted frequency band between 2 to 10 kHz (can work in most situations), it may be found more suitable to use the frequency range (frequency band) that lies about 3 kHz or higher, and also below the center frequency of the emitted infrared radiation. Thus, the receivers are tuned (or, in other words, “synchronized”) according to the emitted infrared radiation (at a central frequency of 15 kHz), providing the possibility of detecting infrared radiation in the range from 12 to 18 kHz (for example, by using a band pass filter tuned to from 12 to 18 kHz). Frequencies outside such a band are thus suppressed to a large extent, while frequencies within the band from 12 to 18 kHz are amplified with a maximum gain located at a center frequency of 15 kHz, for example, up to approximately 53 dB.

By working with a modulated frequency in the emitters and receivers of exposure, for example, bright sunlight, which otherwise can cause the saturation of the received infrared signal in comparison with any reflected signal, they are essentially eliminated by allowing the device to work in conditions of illumination of backlighting up to up to approximately 10,000 lux.

Figure 4 shows a sequence of individual scan cycles (i.e., emitting pulsed infrared radiation) at a first scan frequency having a time between individual scan cycles t1, a second scan frequency having a time between individual scan cycles t2 that is shorter than t1 (i.e. is a higher scanning frequency than t1), and a third scanning frequency having a time between individual scan cycles t3, where t3 is greater than t1 and t2. The time between individual scan cycles is measured as the time between the start of one single scan cycle until the start time of the next separate scan cycle. Each of the individual scan cycles is shown here as having the same pulse intensity (that is, no adjustment is made between the individual scan cycles to account for the previously received reflected scans, which may result in different emissive power supplied to the IR emitters). The additional time t4 is shown, which is a predefined time interval or a predetermined number of pulses divided by time t1 (the first scanning frequency), which must expire before the system changes the scanning frequency to the third slowest scanning frequency with a time interval t3. The pulse duration of each individual pulse is usually constant.

The time t1 is set at a constant level to be between 0.15 to 1.0 seconds, preferably from 0.15 to 0.4 seconds, that is, from the condition that a separate scanning pulse is separated by an equal time t1. Time t1, however, can vary, and exactly the right frequency for optimizing the device for the sake of saving battery power and the reaction time before dosing were found to be around t1 = 0.17 seconds. The second scan frequency is always faster than the first scan frequency, and t2 is set to preferably be between 0.05 to 0.2 seconds, preferably between 0.08 and 0.12 seconds, between scan cycles. Time t2, however, may vary to be another suitable value, but is preferably between 30% to 70% t1. The time t3 can be set between approximately 0.3 and 0.6 seconds, although a longer time t3, such as 1 second or even longer, is also possible. However, starting the operating time of the radiating circuit (in particular by using an RC starting circuit using an RC time constant to cause a discharge of current with respect to the microprocessor to initiate the synchronization operation) is most suitable if t3 is set to double the duration of t1. Thus, t3 can be set to 0.34 seconds in the case where t1 is 0.17 seconds. The initial moment t1 can be made variable, for example, by means of a variable resistor controlled from the outside of the device, although, typically, this can be a factory setting in order to avoid inadvertently changing the time t1, which is inappropriate in certain situations.

The time t4, typically, can be selected to be between 30 seconds to 10 minutes, and can also be adjusted in a variable manner in the device depending on the type of use and the environment that is usually found where the device should be located. However, a suitable value for optimized operation was found to be approximately 300 seconds, although it can also be great where additional energy is required to be saved.

Although not shown, it will be apparent that additional time periods can also be set in the device with intermediate time periods (i.e., intermediate between t1 and t2 or intermediate between t2 and t3, etc.) or even longer time periods, depending from operating conditions, although the use of three different scanning frequencies has been shown to take into account most situations with good performance, based on reaction time and energy conservation. For example, an additional time period longer than t4, for example, 30 minutes, occurring during the duration of the scan cycles with an interval of t3, could be used to change the time period between scan cycles to be longer than t3 (for example, 10 seconds between individual scan cycles). This situation may be useful when the dispenser cannot be used hard during night time periods. The reason for this will become clearer by reading the following job description.

As can be seen in FIG. 4, after four scanning cycles S1-S4 with a time interval t1, the scanning frequency changes to a second faster scanning frequency with an interval t2 and remains at the second scanning frequency for two further scanning cycles S5 and S6. The reason for this change will be explained below with reference to FIG.

5 shows an example of a possible level (received signal strength) of the received signals R1-R7 caused in response to the emission of the scanning pulses S1-S7.

The approximate background infrared level is indicated as the received signal level Q0. This level of Q0, of course, can vary, and, as further shown below, this, however, can be taken into account. For ease of explanation, however, the following example assumes that Q0 remains essentially constant.

When S1 is emitted and there is no object that is not considered in the last background value of the received signal, the background level received at R1 will be approximately at the level of Q0. Similarly, in the next scanning cycle S2, the level of the received infrared radiation is also close to Q0 and therefore does not cause a change in the first scanning frequency. In the scanning cycle S3, the level R3 of the received signal, however, is above the background level, but only to the very minimum extent (for example, less than a predetermined value, for example, less than 10%, higher than the level of background IR radiation), and the strength of this is retained by the first scanning frequency. Such small changes (below a predetermined level) above or below Q0 can occur due to temporary changes in humidity levels or persons moving a greater distance from the dispenser, or spurious IR radiation due to changes in sunlight or temperature conditions around the dispenser.

In the scanning cycle S4, the level of the received signal has reached or exceeded a predetermined value, for example, 10% higher than the background infrared radiation, and the sensor system and its control device thus assume that the likely user (e.g. hands or the entire body of the user) moves closer to dispenser in order to remove the product, such as a paper towel. In order to be able to respond faster when it is assumed that the user wants the towel to be dosed (that is, when the level of the received signal reaches or exceeds a predetermined value, for example, 10% higher than the background infrared radiation), the scanning frequency accordingly increases to a second scan frequency and thus produces the next scan pulse with a shorter time t2 after the previous pulse.

If the signal level R5 received in the next scanning cycle S5 also satisfies the existence criteria at or more than a predetermined level above the background IR radiation (for example, at or more than 10% above the background IR radiation in accordance with the criteria used for the previous scan cycles), the sensor system registers through a counter (for example, in memory or another form of register) a single detection above a predetermined level, and then gives an additional scan cycle S6 interval t2 to check whether the received infrared radiation is still at or above a level, for example, 10% greater than Q0 of the background infrared radiation. As shown in FIG. 5, this is the case for the scanning cycle S6, and the control system of the sensor system (containing both software and a microprocessor in a preferred form) then immediately outputs an output signal to the motor M to start the rotation of the motor in order to dispense the product (for example, a portion of paper 7 from roll 3). In this case, when two consecutive scanning cycles are above a predetermined level, the system accordingly determines that the potential user is in the zone, demanding that the product be dosed, and thus determines that the user is in the “dosing" zone.

In the case where only one set of sensing elements is used to detect the presence of the user in the first detection zone (for example, the embodiment of FIGS. 1 and 2), the detection zone and the dispensing zone will be the same physical zone, but it is only a touch a control system that logically determines that the user has entered the dosing zone.

However, in the embodiment of FIG. 3, where an additional sensing element 3 and / or 21 is used, the signal level R4 will be recognized in zone 18 and thus will cause the first scan frequency to change to the second scan frequency even before the user enters zone 17, which, in the case of FIG. 9, would be a metering zone that is different from the first detection zone 18. Zones 17 and 18, of course, could overlap to a lesser or greater extent, but zone 18 in this case always has at least a part of it that is arranged to extend farther from the dispenser than zone 17. In this case, however, for the second scanning frequency is appropriately maintained for a time suitable for the user to physically enter zone 17 (e.g., time to move to the sink, wash hands, and then use a towel). Such a suitable time, for example, can be set between 1 and 10 minutes, during which time a second scanning frequency is maintained, pending the reception of reflected IR signals R that satisfy the criteria by which the product should be dosed.

In an additional situation, it is not shown where the level at R5 is below a predetermined level (for example, 10% above the background IR radiation), the system can be programmed to issue an additional scan cycle and again check whether the level of the received signal is at or above a predetermined level in order to indicate that the user is present and wishes to receive a towel. Thus, it is preferable that the two consecutive scan cycles to invoke two received signals having a received signal intensity above a predetermined level be more than constant, it was found preferable to allow any two or three consecutive scan cycles to be above a predetermined level . Of course, there are also additional possibilities, due to which the number of scan cycles to enable dispensing of the towel would be any two of four consecutive scan cycles, or any three of four consecutive scan cycles, or additional combinations. However, with t1 set to 0.17 seconds and t2 set to 0.1 seconds, it was found appropriate to provide any two of the three consecutive scanning cycles with the ability to start dispensing the product, as this gives very reliable results.

In the case of FIG. 4, after the towel or other article has been dispensed (released), the system changes the scanning frequency back to the first scanning frequency in order to save energy, and thus the scanning cycle S7 is emitted at a time t1 after S6 scan cycle. It is clear that this saves energy as timely as possible. However, the second scanning frequency may last longer if required (the situation is not shown in Fig. 4), so that when the user again wishes to receive a second or additional product (for example, an additional towel), again moving his hands to the dispenser outlet, again quickly dosing occurs.

In the case shown in FIG. 5, the case corresponding to FIG. 4 is shown, where the user, for example, tore off a piece of paper that has been dispensed from the dispenser, and thus the IR level received at R7 has moved back below a predetermined level (for example, below a predetermined level of 10% or more than Q0).

A predetermined level above the background level at which the control system of the sensor system causes the release of the product has been described above as existing 10% above the background for two of three consecutive scanning cycles. However, practical tests have shown that a more suitable level is at or above 12% more than the background IR radiation and even more preferably at or above 15% more than the background IR radiation. This is intended, for example, to take into account the changing lighting conditions that may occur when the user is close to the dispenser, but actually does not want to use it.

However, during the test it was also found that the increase in reflected infrared radiation, which is received, makes it possible to use completely different threshold values in those cases when required. Thus, sensor circuits, for example, can be adjusted so that the predetermined level above the background level is up to 90% or more, even up to 95% or more, above the background IR radiation before dosing occurs. This, for example, provides the possibility of a much better discrimination between the reflection from the user's hands compared to any unwanted received infrared radiation with a bandwidth of the frequency spectrum of the pulse from 12 to 18 kHz (for example, in the case of very bright lighting). At the same time, the proximity at which such a high level occurs is usually less than when a predetermined level is used, until the current in the emitters is slightly increased.

In some cases, users can move their hands very quickly toward the dispenser and may be annoyed to have to wait for some time longer than it is necessary for the first scan frequency to be replaced with the second scan frequency and wait an additional 0.2 seconds (when using t2 = 0.1), even if it is, in most cases, an insignificant time. An additional manual correction control unit can thus be included in which any single received scan signal is 30% higher or higher (or a higher value, such as higher than 95%, in the case described in the previous paragraph) compared to the background level can be used to call the immediate dosing of the product, without the requirement of successive scanning cycles at or above a predetermined level, even in the mode of the first (lower) scanning frequency. This can also be done in the second scan frequency mode.

After a period of inactivity for a long time period t4, during which the sensor system was scanning at the first frequency, the system may be allowed to assume that there are no possible users nearby the dispenser. In this case, even the time t1 can be considered too short to allow optimal energy conservation, and thus the system can change the scanning frequency to a third scanning frequency lower than the first scanning frequency, during which the scan pulse is issued only once after the time has elapsed t3. However, in this case, when one IR signal is received that is at or above a predetermined level (for example, 15% or more above the background level), then the system must change the scan frequency directly to a second higher scan frequency, preferably than first adopting the initial first scan frequency. However, in such a case, it is appropriate to require at least two scan cycles, but preferably a larger number of scan cycles, to cause dispensing of the article. For example, when the toilet room where the dispenser is placed is plunged into darkness, and then, at some point in time, the lamps turn on, the received infrared levels can be taken into account to determine that the user is present. In order to avoid dosing the product in such a case, it may be appropriate to allow the system to have time to account for the levels of background infrared radiation before being able to dose.

In terms of the background level of infrared radiation, as mentioned above, such will vary with time. Similarly, the presence of immovable objects (such as soap dishes, other containers or other immovable objects) within the dispenser area must be taken into account as background IR radiation. In order to do this, it was found appropriate to obtain a moving average of the most recently recorded received IR signals R in order to continuously change the level of Q0.

For example, four (or more or less than four) of the most recently received infrared signal values can be used to generate the average level of the background signal, for example, by dividing the sum of the four most recent received signal levels by four. As each new IR value is received, the oldest of the four values is removed from the calculation (for example, by removing it from the register or drive of the latest values in the control circuit) and calculating the new average value based on the latest values. The calculation of the moving average and the means required for this in both hardware and / or software for the most recently recorded set of values are very well known in the field of electronics and are thus considered to be without further explanation.

By using such a moving average level of background infrared radiation, an additional advantage is obtained that when a user who has just removed a towel or other product holds his / her hands at the dispensing outlet, the level of received infrared radiation will remain high. However, in order to prevent the user thereby causing the release of large quantities of the product, such as paper towel material, the user's hands will be considered as being background IR radiation when they are relatively stationary, and thus dosing will not occur. To dispense an additional product (such as paper), the user therefore needs to remove his / her hands from the sensing element of the dispenser in order to allow reading of the “true” background IR radiation (that is, background IR radiation without the user's hands present too close to the device ) Only with the renewed movement of the user's hands in the direction of the sensing elements of the dispenser can dosing of the product be called up to occur again.

In addition, another additional means by which misuse of the dispenser can be prevented when the towels are re-removed excessively is to organize or even as an alternative to the above moving average an adjustable minimum elapsed time between dispensing towels (e.g., time between 2 and 10 seconds). However, this symptom is usually not required, since in most cases the inherent expiration time for the system to determine the user as being present in the dispensing zone and to rotate the electric motor to dispense the towel will be sufficient to prevent such misuse.

It will also be appreciated that, as the metering batteries discharge over time, the power supplied to the sensing elements may also be affected, which may cause less efficient operation. In order to prevent this from occurring and thus guarantee that a constant voltage is available for supplying the sensing elements (up to a time close to the full discharge of the batteries), a constant current load can be applied. Such constant current loads to ensure voltage stability are well known per se in the field of electronics, and thus are considered not to require further description, although it may be understood that their use in a sensor circuit for such a dispenser as described in the materials of this application is particularly useful. The amount of additional energy required to control the constant current load is negligible, and, accordingly, the use of such a device is barely noticeable in a usable battery life.

The power supplied to the emitters can additionally be configured to vary by automatic control, respectively, between a value of 0.001 mA · s to 0.1 mA · s (when using a battery assembly of 6 V), in order to take into account the received intensity of the reflected signal from the previous ones scanning cycles and to adjust the level of emitted infrared radiation to a more suitable level. This can be achieved by changing the current in the emitters, for example, between 1 mA and 100 mA (that is, the possibility of a 100-fold change). This can be done by using a PWM (Pulse Width Modulator, PWM) module 106 (to be described later), whereby a rectangular PWM signal is converted to a direct current voltage (DC) having an output power proportional to the PWM duty cycle, and by virtue of whereby the MCU changes the PWM duty cycle to adjust the DC voltage in the emitter circuits and, accordingly, the power of the emitted IR signal based on the input signal intensity received by the sensors and sent to the MCU. For example, if the intensity of the reflected signal is very low in the last few scanning cycles (for example, five scanning cycles) when dosing occurred, this may be because the typical brightness of the user's hands is low and the background lighting levels are relatively high. This can cause an increase in the levels of the received signal only slightly above a predetermined level compared to the background infrared radiation, while the user's hands are not located very close to the sensitive elements, which can lead to difficulty in detection in some conditions. In such a case, it may be appropriate to increase the power supplied to the IR emitters in order to receive a more easily perceptible signal change. Similarly, if the typical brightness of the user's hands is high and the background IR levels are low, it may be appropriate to lower the power supplied to the IR emitters, while an easily perceived change in signal level is received (i.e., the level of reflected IR radiation during dosage compared to the level of background infrared radiation). In this way, the power supplied to the emitters, in addition, is further optimized to take into account such conditions, along with the provision of reliable and fast recognition and dosing. Thus, in addition to very high light conditions, only very low power can be used with respect to sensors. Thus, it will also be understood that the dispenser can be optimized so that the first detection zone, in which the presence of a possible user causes a change from the first to the second scanning frequency, is selected between approximately 20 and 60 cm, preferably between 25 cm and 50 cm from the outlet. It will be obvious that additional power increases with respect to the emitters will increase the detection range, but power consumption will increase to a much greater extent, and false detection can also occur more often. A range of up to 50 cm from the dispenser to enable user detection is the preferred maximum.

An alternative, possibly simpler method, which can be used to change the current of the infrared emitter, rather than by comparing (as above) the values of the reflection levels with the general background, is to set the so-called "standard value" or "threshold value "In the control circuit, which is the value of the expected intensity of the detected signal received under normal operating conditions. The supplied current can be, for example, 5 mA. If this standard value is called A1, then during operation the control circuit (its MCU) can be made to calculate the level of infrared radiation, A2, according to a predetermined number of the most recently received infrared radiation values (that is, the moving average of the most recent values). If A2> A1 (that is, the level A2 of the moving average detected reflection signal is higher than the stored standard signal level A1), the current supplied to the emitter can be reduced preferably in incremental steps. Similarly, if A2> A1, then the current supplied to the emitters can preferably increase with a certain increment.

In an additional preferred embodiment of the invention, the dispenser may be configured to have two modes of operation, one that is the recognition mode described previously, by virtue of which active perception of infrared radiation is active, the other that is the mode of “hanging” the towel, for example, by virtue of which, every time a paper towel is dosed and also removed (for example, torn off), a new paper towel is released from the dispenser. For this purpose, for example, the cutting edge 16, as shown in FIG. 2, could be set so that applying pressure on the cutting edge (often referred to as a cutting mechanism) causes the switch to be actuated to start the electric motor M to give out a new a piece of towel ready to be torn off. The device may also include a manual switch, so that this mode of hanging towels can be set manually by the user or automatically by a timer, for example, with known time periods when the dispenser will normally be in constant use, and the use of an active IR sensor system is temporarily unnecessary.

The “hanging” mode of a towel, for example, may also be suitable in conditions of excessively high background infrared radiation, when the sensor system is completely saturated and thus cannot detect a difference in the increased level of infrared radiation from the user compared to background levels or at times close to full battery discharge when the power consumption of the active IR sensor system is inappropriately high for the remaining energy. Automatically switching to this mode and disabling active recognition of infrared radiation at very high background infrared radiation (for example, at or above 10,000 lux) and when the batteries are completely discharged in this way can have advantages.

6 shows a block diagram of a basic system according to one embodiment of a dispenser according to the invention, in which the part shown by the dashed line includes the main components for modulating the infrared signal, emitting infrared radiation and receiving infrared radiation used to transmit the signal recognition in (analog / digital) A / D modulation of the main control unit (MCU), which device contains a microprocessor.

Rectangle 101 and 102 denotes infrared emitter (s) and receiver (s), respectively, generally corresponding to the previously described emitters 10, 12 and 9, 11, 13. These infrared emitters and receivers are preferably photodiodes. The user's hand, shown outside the dashed lines, indicates that the infrared radiation emitted by the emitter (s) 101 is reflected by the hand back to the receiver (s) 102. The node 103 is a photoelectric converter for converting the received infrared signal before it is passed to the filtering and amplification unit 104, where the pass-through bandpass filter and amplification circuits act to amplify the received signal near the center frequency in a limited bandwidth and thereby to proportionally suppress other frequencies of infrared radiation. The signal is then passed to the signal rectifier 105 because the IR signal is an AC signal. From node 105, the signal passes to the A / D module of the MCU.

To emit an infrared signal, an analog pulse width module 106 is used to control the infrared emission power. The output of the PWM module 106 is controlled by the MCU so that the square-wave signal of the PWM can have its duty cycle variable by the MCU to control the DC voltage in the emitter circuits and thus the power of the emitted IR signal. The PWM 106 is connected to the D / A converter 107 and to the node 109 of the excitation circuit of the infrared emitter, which includes a constant current load mentioned earlier. The same excitation circuit of the IR emitters also provides a signal from the phase-detection module 108, which produces a 15 kHz pulse modulated signal (± 0.5%) (or another modulated signal frequency that is considered appropriate) in order to excite the emitters 101 through emitter driving circuit 109 for emitting modulated IR signals for short intervals (for example, each signal is emitted for approximately 1 ms). In this regard, it should be noted that before the modulated signal is emitted, the MCU, first of all, must already put into operation the filter and amplification circuit assembly 104 for the received signal for a short period, for example 2.5 ms, before emitting the modulated pulse, in order to allow the receiver circuit to stabilize in order to reliably detect reflected IR radiation from the emitted IR signal. Since the assembly 104 is already in operation when the infrared scan pulse is emitted, and since the filters and the amplification assembly are centered on the center frequency of the emitted pulse, there is no need to synchronize the timing of the emitted pulse and the received pulse to any additional degree.

The signal from the node 109 delivers the information to the on / off control unit 110 of the IR emitter. The MCU I / O module 118 also supplies a signal to the node 110 to turn on and off, as necessary, thereby performing a scan cycle of infrared radiation through the emitter 101.

In order to drive the microprocessor (that is, put it in an active state to perform a scan cycle at a certain frequency), the launch RC circuit 115 supplies a signal to the MCU, to the transition detection unit 114 to the active state. Node 117 is an external interrupt detection node.

From I / O module 118, there is a transfer to node 119, which can be considered as a motor control circuit, which drives motor M when the sensor system (which preferably includes MCUs and software) has detected that the product must be dosed due to the determination the presence of the user in the dosing zone.

Additional peripheral nodes 111, 112, respectively, are a paper recognition circuit assembly and a low power detection circuit (i.e., for detecting batteries close to full charge). The node 116 indicates the battery power that is used to drive the MCU, as well as all other external devices and the electric motor. The assembly 120 may be a motor overload circuit that cuts off power to the motor, for example, when paper becomes jammed in the dispenser or when there is no paper in the dispenser. Node 121 is a paper length control unit that operates so that a constant paper length (which in itself is variable adjustable by manual operation, for example, with a variable resistor or the like), each time the electric motor is made to dispense some the length of the paper sheet 7 through the outlet 8. This assembly 121 may also include a low power compensation module, whereby the electric motor is rotated at low power in over a longer period of time in order to dispense an identical length of the paper sheet, although the assembly may simply be a pulsed position control system by which the rotation of the electric motor is counted by a sequence of pulses and the rotation is stopped only when the exact number of pulses is reached. Such a pulsed position control system, for example, could include a rigidly located photo interrupter that can detect gaps in a corresponding split unit attached to the drive shaft of the electric motor (or, alternatively, on the drive roller 5, operably connected to the drive electric motor) . The assembly 122 may be an insufficient paper detection circuit, and the assembly 123 may be the assembly used to indicate whether the housing is open or closed. This, for example, can be used to automatically feed the first portion of paper from the paper roll through the outlet when the housing is closed, for example, after refilling with a new roll of paper, so that the person refilling the dispenser is sure that the device is dispensing properly after of how it was closed.

Although not shown here, a sequence of warning or status lights may be associated, for example, with various nodes, such as nodes 111, 112, 120 to 123, to indicate specific conditions to a potential user or person servicing the dispenser or repair worker (e.g. if the batcher electric motor is jammed or the batcher needs to be re-filled with paper, or the like).

FIG. 7 shows one embodiment of an RC control circuit that can be used to provide a synchronized microprocessor active state transition in an MCU. The principle of such a circuit is widely known, and in the present case, a suitable value for the Re resistor is 820 kOhm, and for a capacitor 0.33 microfarads. Although not shown specifically in FIG. 6, the active state RC circuit uses the MCU I / O 118 to provide a synchronized active state function of the microprocessor, so that a scan cycle occurs at a prescribed time interval (for example, t1, t2 or t3 ) When there is a drop from high to low voltage at the input / output as a result of the RC circuit, the MCU will “go into active state” and perform a scan cycle. This transition to an active state leading to a scan cycle also requires software support. Similarly, the length of time t1 and / or t2 and / or t3 can be appropriately performed as a multiple of the time constant of the RC circuit, whereby the input signal from the RC circuit can be used in software to determine whether or not scan cycle in each interval. In this regard, it will be noted that the RC circuit undergoes changes in the input voltage (via VDD, which is the MCU power supply obtained after passing through the diode from the battery voltage source). As the voltage of the battery (or batteries) drops, there will be an increase in the RC time constant in the circuit of FIG. 7, and thus the time intervals t1, t2 and t3 set initially will change as the batteries become more depleted. For example, with a time interval t1 set at a predetermined level of 0.17 seconds for a battery level of 6 V, dropping to a full discharge level of 4.2 V will increase the time interval t1 to 0.22 s. Thus, the values of t1, t2, t3, etc., as used in the materials of this application should be understood as being values at a fully discharged battery source.

Fig. 8 shows a modified RC circuit which has the advantage of using less current than the circuit shown in Fig. 7. In FIG. 8, three bipolar transistors are used to minimize the current used when the MCU is inactive.

Under normal conditions, the digital circuitry inside the MCU operates in a high voltage logic state and a low voltage logic state in which the load current is very low. However, when the active state RS-circuit is connected, as in FIG. 7 (whereby the indication “to the MCU” assumes connection to the MCU I / O port), this creates a step-like voltage change on the MCU I / O port, which is proportionally increasing abrupt change in voltage due to the process of charge and discharge in the RC circuit. This creates a relatively long period of operation for the digital circuit in the MCU, which in turn results in an internally higher power consumption in the internal circuits of the IC (integrated circuit, IC) than is present during normal operating conditions. This results in somewhat higher power consumption for the MCU during its “shutdown” cycle (that is, the “inactive” MCU cycle).

According to the diagram of FIG. 8, the modification includes the use of two input / output ports PA7 (on the right side of the figure) and PB7 (on the left side of the figure) of the MCU. An important aspect of this circuit is that two transistors Q2 and Q3 have been added to the cascade, which together modify the characteristics of the RC discharge. The output of the PA7 MCU, in this case, gives a steeper discharge curve. The delay time constant for switching the MCU to the active state is determined according to R4 and C1, which were set to 820 kΩ and 0.68 μF, respectively, in the example shown. Of course, other values for other time constants can be selected.

A quick, abrupt change in voltage at port PA7 is achieved after conversion to Q2 and Q3, which minimizes the time required to switch from a high voltage logic level to a low voltage logic level. A circuit such as in FIG. 8 can achieve a power reduction of about 40% during an idle cycle compared to circuits of circuit 7 for approximately the same RC time constants. Thus, the RC timing chain of FIG. 8 is particularly useful in cases where maximum energy is to be saved.

Claims (34)

1. A dispenser for automatically dispensing a product stored in the product stock of said dispenser, said dispenser comprises a sensor system for detecting the presence of a potential user, to which said article can be dispensed, while said sensor system is configured to scan for the presence of a possible user at a first frequency scanning at a second scanning frequency and at a third scanning frequency, wherein said second scanning frequency being higher than said first scanning frequency, and said third scanning frequency being lower than said first scanning frequency, and the sensor system is configured to change said scanning frequency from said first scanning frequency to said second scanning frequency, when a potential user is determined to be detected by said sensor system located within the first detection zone, and wherein the sensor The said system is configured to change said scanning frequency to said third scanning frequency when the sensor system has not determined the presence of a possible user for a predetermined time period. 2. The dispenser according to claim 1, wherein said first detection zone includes an area that is located at a more remote distance from the dispenser than the detection zone, and wherein the sensor system is arranged so that a possible user defined by the sensor system in as penetrated into the dosing zone, causes the said dispenser to dispense the said product. 3. The dispenser according to claim 1, wherein said dispenser is a paper dispenser. 4. The dispenser according to claim 1, in which said stock of the product includes a stock of non-perforated paper and wherein said dispenser contains an outlet with a cutting edge located in close proximity to said outlet and with respect to which cutting edge said paper can be proportionate move in order to cut off said paper to remove the cut portion. 5. The dispenser according to claim 1, wherein said dispenser is a dispenser of paper towels for hands and wherein said stock of products is in the form of a continuous sheet of paper, preferably in the form of a roll. 6. The dispenser according to claim 1, in which the sensor system comprises infrared radiation sensors, including at least one infrared emitter and at least one infrared receiver, arranged at the outlet of said dispenser. 7. The dispenser according to claim 6, in which the sensor system comprises at least two infrared emitters and at least three infrared receivers for detecting the presence of a potential user. 8. The dispenser according to claim 7, in which in the lateral direction of the outlet of the dispenser, the receivers and emitters are arranged in series in the form of a receiver / emitter / receiver / emitter / receiver. 9. The dispenser according to claim 1, in which the first scan frequency is a frequency of from 0.15 to 1.0 s between single scan cycles, and said second scan frequency is a frequency of from 0.05 to 0.2 s between single scan cycles. 10. The dispenser according to claim 1, in which the first scanning frequency is a frequency of from 0.15 to 0.4 s between single scanning cycles, and the second scanning frequency is a frequency of from 0.05 to 0.15 s between single scanning cycles. 11. The dispenser according to claim 1, wherein the predetermined time period is at least 60 s. 12. The dispenser according to claim 1, wherein said sensor system comprises an additional sensor arrangement including at least one emitter and one receiver configured to detect the presence of a potential user at a distance of more than 50 cm. 13. The dispenser according to claim 12, wherein said sensor arrangement is located in the dispenser on its outer surface so as to face forward and outward, said arrangement is preferably located on the outwardly facing front of said dispenser, so that at least part emitters of the sensor arrangement protrude outward from said dispenser. 14. The dispenser according to claim 4, in which the specified dispenser includes a housing containing an outlet. 15. The dispenser according to claim 12, wherein said additional sensor arrangement is arranged at a location remote from said dispenser and, during operation, is connected to said dispenser sensor system via a wired communication line or a wireless communication line. 16. The dispenser according to claim 1, wherein said sensor system includes a control system configured to detect a possible user depending on the signal intensity of the received infrared emissions, so that the possible user is determined to have penetrated into said first zone when said the sensor system detects a change in the intensity of the received signal, which is more than a predetermined value, higher than the intensity level of another signal, I will mention th change in the intensity of said received signal level is the predetermined signal intensity level above the background intensity level signal. 17. The dispenser according to clause 16, wherein a potential user is determined to have entered the dispensing zone when said sensor system is operating at said second scanning frequency, and when said control circuit detects a signal intensity greater than a predetermined signal intensity level compared to the intensity level of the background signal, for a predetermined number of single scan cycles at said second scan frequency, thereby prompting said dispenser to dispense the product. 18. The dispenser of claim 16, wherein said predetermined signal intensity level is 10% greater than the background level. 19. The dispenser of claim 16, wherein said predetermined number of single scan cycles at said second scan frequency are between one and five scan cycles. 20. The dispenser according to clause 16, in which said control system is configured to recognize the user as penetrated into the dosing zone when the intensity of the received signal in one single scan cycle at the first or second scan frequencies is 30% or more than the level background signal. 21. The dispenser according to claim 1, wherein said second scanning frequency is maintained for a predetermined time period after said control system has prompted said dispenser to dispense the article before returning to said first scanning frequency. 22. The dispenser according to claim 1, wherein said second scan frequency is maintained for a predetermined number of scan cycles after said control system prompts said dispenser to dispense the article before returning back to said first scan frequency. 23. The dispenser according to claim 1, wherein said sensor system changes said second scanning frequency back to said first scanning frequency, immediately after the sensor system has registered that the product is to be dosed. 24. The dispenser according to claim 1, wherein said sensor system is configured to emit infrared radiation with only a first limited emission frequency band and said sensor system is configured to detect radiation in a limited detection frequency range with a passband between about 2 to 10 kHz, both above and below the aforementioned first emission frequency band. 25. The dispenser of claim 24, wherein said first emission frequency is about 15 kHz, and said detection frequency range is between about 12 and 18 kHz. 26. The dispenser according to claim 1, wherein said sensor system is an infrared sensor system, wherein the power supplied to one or more emitters of said sensor system is variable so as to be able to change the intensity of the emitted infrared signal. 27. The dispenser of claim 26, wherein the power supplied to said one or more emitters increases when the average signal level of a predetermined number of the most recent received previous scan cycles is less than at least the first predetermined signal level and in this case, the supplied power decreases when the average energy level of a predetermined number of the most recently received previous scan cycles is large them than said first predetermined signal level. 28. The dispenser according to claim 27, wherein the power supplied to said one or more emitters is determined so that a possible user will cause a change from said first scanning frequency to said second scanning frequency when said user is located at a distance up to where- anywhere between 20 and 60 cm from the outlet of said dispenser. 29. The dispenser according to claim 1, wherein said sensor system includes means for detecting background infrared radiation, said means including a storage device of a predetermined number of the most recently received infrared radiation detections obtained during scanning, and wherein the value of the aforementioned predetermined amount of the most recently received infrared radiation detections is taken as the background infrared level go radiation. 30. The dispenser according to claim 1, wherein said dispenser includes a device for adjusting the minimum time between dispensing one product and dispensing the next product. 31. The dispenser according to claim 30, wherein said device for setting the minimum time between dispensing one product and the next product can be set to zero so that the time between dispensing one product and the next is determined by the minimum return time characteristic of the system. 32. The dispenser according to claim 1, in which the dispenser and the sensor system operate on battery power by means of a battery located in the dispenser housing. 33. The dispenser according to claim 1, wherein at least the first scanning frequency is set by the RC synchronization circuit operating in conjunction with software controlled by the microprocessor, wherein said microprocessor is brought into active state by the said RC synchronization circuit, which supplies current to the microprocessor input at the end of each RC time constant, and which causes said microprocessor to be inactive between scan cycles. 34. The dispenser according to claim 33, wherein the RC synchronization circuit includes three bipolar transistors, two in cascade, and two connections to the input / output section of said microprocessor.

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