Patent Publication Number: US-2021186275-A1

Title: Dispenser, retrofit kit for a dispenser, a method for provision of portions of a tissue web and method for upgrading a dispenser

Description:
CROSS-REFERENCE TO FOREIGN PRIORITY APPLICATION 
     The present application claims the benefit under 35 U.S.C. §§ 119(b),  119 ( e ),  120 , and/or 365(c) of European Application No. EP 19218314.3 filed Dec. 19, 2019. 
     FIELD OF THE INVENTION 
     The invention relates to a dispenser for provision of portions of a tissue web, a retrofit kit for a dispenser, a method for provision of portions of a tissue web, and a method for upgrading a dispenser. 
     BACKGROUND OF THE INVENTION 
     Dispensers and methods for provision of portions of a tissue web are known, for example, from EP1191872B1, EP2810259B1, EP0283554B1, EP0483314B1. Existing dispensers and methods, however, in practice still have room for improvement regarding reliability and trouble-free operation. 
     SUMMARY OF THE INVENTION 
     Therefore, it is an object of the present invention to provide an improved dispenser for provision of portions of a tissue web, an improved retrofit kit for a dispenser, an improved method for provision of portions of a tissue web, and an improved method for upgrading a dispenser. In particular, it is an object of the present invention to provide a dispenser for provision of portions of a tissue web, a retrofit kit for a dispenser, a method for provision of portions of a tissue web, and a method for upgrading a dispenser, which are highly reliable and/or reduce troubles and/or faults during operation. 
     According to a first aspect, it is provided a dispenser for provision of portions of a tissue web, comprising a first transport arrangement for unused tissue and a second transport arrangement for used tissue, a housing with a dispensing opening through which a tissue portion located between the first transport arrangement and the second transport arrangement protrudes, a detection arrangement comprising at least one sensor unit, preferably comprising a first sensor and a second sensor, for detecting a user change, a control unit adapted to activate the second transport arrangement when a user change is detected. 
     The dispenser is preferably suitable for washrooms and other hygienic environments. The dispenser comprises a housing. The housing preferably comprises a back part and an openable housing cover with a front face. The housing further has a dispensing opening. 
     The tissue to be dispensed from the dispenser can be a multiuse tissue, such as a cloth towel or microfiber towel, or a single-use tissue, such as a paper tissue or a reinforced paper tissue, for example. The tissue is preferably provided as a continuous web, for example, coiled up to a tissue roll or folded in a stack, e.g., concertina-like. 
     Portions of the tissue web, which preferably means a certain length of tissue to be used by a user, often for drying hands, are provided by the dispenser. The portion to be used by a user protrudes through dispensing opening in the housing, such that the user can access the portion. Preferably, the portion is provided as a hanging loop of tissue web. For example, the dispensing opening may have a front and a back slot, preferably separated by an intermediate part of the housing. For example, a part of the tissue portion facing the user may protrude through the front slot and a part of the tissue portion facing the wall (in a wall-mounted dispenser) may protrude from the back slot. 
     Preferably, the dispensed and used portions of tissue can be retrieved and coiled, for example, within the dispenser. Usually, the used multiuse tissue is removed by service personnel, washed and recycled, and then provided for a further use cycle. Once a tissue roll is empty, usually a new tissue roll, which also can be a recycled tissue roll, is inserted into the dispenser and received there by some form of holding arrangement. 
     The dispenser comprises a first transport arrangement for unused tissue and a second transport arrangement for used tissue. The tissue portion protruding through the dispensing opening is located between the first transport arrangement and the second transport arrangement. Preferably, the first transport arrangement is adapted to provide unused tissue in the form of a continuous web by uncoiling it from a roll of unused tissue. Further preferably, the second transport arrangement is adapted to retrieve used tissue, preferably by coiling it to a used tissue roll. 
     Dispensers with a first and second transport arrangement, in particular, dispensers with a multiuse tissue web that is retrieved after use, can also be referred to as retracting dispensers. 
     The dispenser further comprises a control unit adapted to activate the second transport arrangement. Preferably, the control unit is further adapted to activate the first transport arrangement and/or to deactivate the first transport arrangement and/or to deactivate the second transport arrangement. Further preferably, the control unit can be adapted to control further elements of the dispenser. 
     The dispenser further comprises a detection arrangement. The detection arrangement has at least one sensor unit for detecting a user change. In particular, the detection of a user change is meant as a detection of a change in the person using the dispenser. For example, the detection of a user change can comprise the detection of a change in the position of a person using the dispenser in combination with the detection of the end of a use and/or the beginning of a new use. Preferably, the detection of a user change can comprise the detection of the departure of a user, possibly including the departure speed of a user, and/or the approach of a user, possibly including an approach speed. 
     Preferably, the sensor unit comprises a first sensor. This first sensor can be the only sensor of the sensor unit. Further preferably, the sensor unit comprises a first sensor and a second sensor. In particular, the first sensor and the second sensor can be employed together for detecting a user change; for example, having a first sensor detecting a change in the position of the person using the sensor and the second sensor detecting the end and/or beginning of a use. 
     The sensor unit can comprise one or more sensors, e.g., a first sensor and possibly further sensors like a second, third, fourth or further sensors. The sensor(s) of the sensor unit can be separate sensors. The sensor(s) of the sensor unit also can be integral and/or an integrated sensor and/or integrated into one single sensor element. For example, the sensor unit and/or one of its sensor(s) can be adapted to generate one or more sensor signals, e.g., based on one or more detection principles and/or one or more detection fields, wherein the detection principles may be the same or different ones and/or the detection fields may be the same or different ones. 
     Preferably, the detection arrangement and/or the sensor unit, in particular, the first sensor and/or a second sensor, is connected to further components of the dispenser, for example, the control unit, in a wired or wireless way. The sensor(s) of the detection arrangement and/or the sensor unit can be connected to each other and/or to further components of the dispenser, for example the control unit, in a wired or wireless way. 
     The control unit of the dispenser is adapted to activate the second transport arrangement upon detection of a user change by the detection arrangement. In particular, it is preferred that such an activation of the second transport arrangement results in the at least partial retraction of the tissue portion protruding through the dispensing opening back into the housing of the dispenser, in particular, by coiling the used tissue on a used tissue roll by the second transport arrangement. 
     The solution as described herein is based on the finding that existing dispensers and methods for providing portions of tissue have drawbacks, in particular, in high-frequency operating situations. High-frequency operating situations typically are situations where a high number of users intends to use the dispenser in quick succession. Existing dispensers, in particular, retracting dispensers, may not be adapted for such a high-frequency use. In particular, the retrieving of used tissue by a second transport arrangement may be too slow or too delayed for such a quick succession of uses. Typically, in retracting dispensers, the retrieval of used tissue by the second transport mechanism takes place after a certain time after unused tissue has been provided to the dispensing opening. The reason for this delay of the retrieval of the used tissue portion is to give a user sufficient time to use the portion of tissue protruding through the dispensing opening. The use of this tissue portion typically takes place by a user grabbing the tissue portion and moving it over his hands for drying hands. A retrieval of used tissue by the second transport arrangement directly after provision of the tissue portion by the first transport arrangement would result in the user not having a large enough portion protruding from the dispensing opening for actually accessing this tissue portion and using it for drying the hands. 
     While this operating principle has a number of advantages and makes sense in a number of regular or low-frequency operating situations, it does have drawbacks in high-frequency operating situations. When a quick succession of users activates the provision of tissue portions from a reservoir of unused tissue, in particular, via the first transport arrangement, to protrude through the dispensing opening in a higher frequency than the used tissue is retrieved by the second transport arrangement, the tissue portion protruding from the dispensing opening will get larger and larger over time. It often happens that the tissue portion protruding from the dispensing opening in such a situation gets too large and thus too heavy to be retrieved by the second transport arrangement. This can lead to so-called “floor loops,” in which the tissue portion protruding from the dispensing opening becomes so large that it reaches the floor of a washroom. 
     The solution as described herein is based on the finding that such drawbacks can be avoided when the second transport arrangement is activated as soon as the person using the dispenser changes. Thus, the solution as described herein provides for a detection arrangement for detecting a user change and a control unit for activating the second transport arrangement upon such detection. When in a high-frequency operating situation the user takes shorter time to dry his or her hands than the usual delay for retrieving the used tissue, the solution described herein detects such a user change and activates the second transport arrangement. This has the advantage that as soon as a user change occurs, the retrieval of the used portion can be initiated. In this way, it can be avoided that two or even more times an unused tissue portion is provided through the dispensing opening before a used tissue portion is retrieved. Increasingly large loops, and even floor loops, can be avoided in this way. 
     The control unit preferably is connected to various components of the dispenser using a wired or wireless connection in order to transfer signals, e.g., sensor signals, activation signals, deactivation signals, control signals, and the like, and to generate and/or process and/or receive and/or transmit such signals. Further preferably, the control unit may, using either a wireless or wired connection, also be connected to external components, for example, a washroom information system, an external communication unit, and/or a backend unit. 
     The control unit preferably is adapted to communicate with an external communication unit and/or with a backend unit, preferably in a bidirectional way and/or in a wireless way. Preferably, information can be transferred from the control unit to the external communication unit and/or to the backend unit. Further preferably, information, such as software updates and/or settings and/or update of (operational) parameters, can be received from the external communication unit and/or from the backend unit by the control unit. It is further preferred that the external communication unit and/or the backend unit is adapted and arranged to communicate, preferably in a bidirectional way, with a plurality of arrangements and/or a plurality of dispensers. For example, the wireless communication can be realized by a Bluetooth connection. Further preferably, the external communication unit and/or the control unit is adapted and arranged to communicate, preferably in a wireless way, such as Bluetooth, to a backend unit, in particular, in order to exchange client specific and/or process related information. Further preferably, the control unit and/or the external communication unit and/or the backend unit is adapted and arranged to communicate with one or more mobile devices like tablets and/or smart phones, preferably in a bidirectional way and/or in a wireless way. 
     Preferably, the dispenser can be part of a system further comprising an external communication unit and/or a backend unit and/or one or more mobile devices. 
     In a preferred embodiment, the control unit is adapted to activate the first transport arrangement when a user change is detected. In this embodiment, the event of a user change can also trigger the activation of the first transport arrangement, which preferably results in dispensing a further unused portion of tissue web through the dispensing opening. In this way, the new user does not need to activate, for example manually or via an automatic, e.g., non-touch, activation mechanism, the provision of a new portion of tissue web. Rather, by activating the first transport arrangement upon detection of a user change, the new user will be provided with an unused tissue portion without the need for further action from his or her side. 
     Preferably, the detection arrangement, in particular, the sensor unit, comprises a third and/or fourth and/or further sensor(s) for detecting a user change. Preferably, also the third and/or fourth and/or further sensor(s) for detecting a user change can have the features, characteristics, and advantages as described herein for the first and/or second sensor. Further, it is preferred that a combination of the sensors of the detection arrangement and/or the sensor unit or all sensors of the detection arrangement and/or the sensor unit contribute to the detection of a user change. For example, some or all of the sensors of the detection arrangement and/or the sensor unit, in particular, their individual sensor signals, may be used and/or assessed as a whole, and/or interdependently, in order to detect a user change. In particular, the detection arrangement and/or the sensor unit and/or the control unit can be adapted to detect a user change and/or to activate the second transport arrangement upon detection of a user change depending on a combination of signals from a plurality or all of the sensors of the detection arrangement and/or the sensor unit. 
     Preferably, the first sensor and/or the second sensor and/or the third sensor and/or the fourth sensor and/or the further sensor(s) can have the same or different detection principles. For example, the sensors can be of the same or different types. In this way, the accuracy and reliability of the detection of a user change can be improved. 
     Further preferably, the first sensor and/or the second sensor and/or the third sensor and/or the fourth sensor and/or the further sensor(s) can have the same or different detection fields. For example, the detection fields of the sensor(s) can vary, e.g., regarding their size and/or range and/or direction and/or sensibility. Again, in this way, the accuracy and reliability of the detection of a user change can be improved. Further preferably, a detection field can be directed upwards, downwards, sideward, forward, rearward, or any combination thereof. 
     Preferably, the detection arrangement and/or the sensor unit and/or at least one of or all of the sensor(s) can be arranged such that the detection field can be adjusted. For example, the detection arrangement and/or the sensor unit and/or at least one of or all of the sensor(s) can be pivotable, e.g., about a horizontal and/or about a vertical pivot axis. This has the advantage that the detection arrangement can be adjusted, for example for different operating situations. 
     In particular, it can be preferred that at least one of the sensors and/or the sensor unit has a detection field in the direction of a user. A detection field in the direction of a user can be directed towards the torso of a user and/or towards the (likely) position of the user&#39;s hands during the drying process. For example, a detection field in the direction of a user can be substantially horizontal and/or angled downwards and/or angled upwards. 
     Further, it can be preferred that at least one of the sensors and/or the sensor unit has a detection field in the direction of the tissue web, in particular, in the direction of the protruding portion of the tissue web, in particular, its part facing the user. 
     In a preferred embodiment at least one of the sensors and/or the sensor unit is positioned on a front face of the dispenser, in particular, on a lower part thereof. Preferably, at least one of the sensors and/or the sensor unit can be positioned adjacent or near the dispensing opening. 
     Further preferably, at least one of the sensors and/or the sensor unit is positioned on an intermediate part of the dispenser housing. Further preferably, at least one of the sensors and/or the sensor unit is positioned inside the housing and/or arranged at the housing, in particular, on its outside or on its inside, and/or separate from the dispenser, e.g., next to the dispenser. 
     In particular, different combinations of the details of individual sensors can be preferred to create a detection arrangement and/or a sensor unit having a high speed and/or high accuracy and/or high reliability and/or short reaction time in detecting a user change while at the same time having a low energy consumption. 
     For example, the first sensor and/or the second sensor and/or the third sensor and/or the fourth sensor and/or the further sensor(s) can be chosen from the following group of sensors, comprising or consisting of: acceleration sensor, motion sensor, thermal sensor, infrared sensor, radiation sensor, in particular, electromagnetic radiation sensor, optic sensor, time-of-flight sensor, capacitive sensor, image sensor, reflective sensor, pyroelectric (passive) infrared sensor, thermopile sensor. 
     In particular, sensors are preferred having sharp signals and/or low noise and/or fast response time and/or low energy consumption. 
     For example, a sensor unit can be preferred having an infrared sensor and an acceleration sensor. As described above, these two sensors of the sensor unit can be separate sensors or implemented as an integrated sensor, providing for both infrared detection and acceleration detection, for example. An acceleration sensor with a low energy consumption can be used, for example, for continuously detecting whether a user pulls the tissue or not. If it is detected that a user pulls a tissue, the infrared sensor (and possibly also a control unit) preferably is switched from an inactive, energy-saving mode, to an active mode. The infrared sensor then preferably detects whether a user approaches and/or leaves the dispenser. The infrared sensor and the control unit can be arranged on a single circuit board, for example. 
     In general, the sensor(s) and/or detection principles and/or detection fields used herein are preferably adapted to detect a user change independent from and/or despite possibly interfering factors such as light, e.g., sunlight, artificial light, UV light, and/or radiation, in particular electromagnetic radiation, and/or electromagnetic fields and/or reflective and/or colored surfaces and/or heat sources like radiators. 
     Further, it is preferred that the sensitivity and/or the detection field of the detection arrangement and/or the sensor/and/or at least one of or all of the sensor(s) can be adjusted. For example, the detection field of a sensor, e.g., of an infrared sensor, can be enlarged or reduced. This can be realized, for example, by positioning a sensor, e.g., an infrared sensor, behind a plate with a hole, acting as an aperture. By varying the distance between the sensor and the plate with a hole, the sensitivity and/or the detection field can be varied. 
     Further preferably, at least two of the first sensor and/or the second sensor and/or the third sensor and/or the fourth sensor or the further sensor(s), preferably three or more or all of the sensors, are arranged on a single circuit board, in particular, a single printed circuit board. 
     Preferably, also the control unit can be arranged on the same single circuit board, in particular, on the same single printed circuit board. Alternatively, the control unit can be provided on a separate (printed) circuit board. The provision of several components on a single circuit board has the advantage of a compact solution which is easy to manufacture and/or to install and/or to exchange and/or to service. A single circuit board also has a cost advantage and can be less susceptible to interference than a cable connection, since unshielded cables may act as antennas and may emit interference signals. 
     In a further preferred embodiment, the second transport arrangement comprises a blocking element, wherein the activation of the second transport arrangement via control unit comprises the release of the blocking element. The blocking element of the second transport arrangement preferably is adapted to block the activation of the second transport arrangement, preferably for a certain time. In particular, it is preferred that the blocking element is adapted to block the second transport arrangement for a certain period of time after the activation of the first transport arrangement. Further preferably, the blocking element is adapted to be released after a certain period of time. Further preferably, the second transport arrangement is adapted to automatically, for example, via a biasing mechanism, such as a spring or an electrically driven mechanism, to retrieve the used portion of tissue web once the blocking element is released. 
     When such a blocking element is present, it is particularly preferred that the activation of the second transport arrangement via the control unit comprises the release of the blocking element. In particular, in case the second transport arrangement is adapted to retrieve the used portion of tissue web once the blocking element is released, the activation of the second transport arrangement may consist simply in the release of the blocking element. Further preferably, the blocking element can be coupled with the activation of the first transport arrangement such that the second transport arrangement will automatically be blocked once the first transport arrangement has been activated. 
     In a preferred embodiment, the blocking element is a time controlled, preferably mechanical, blocking element. A time controlled blocking element preferably is released after a predetermined amount of time. The blocking element can be a mechanical and/or an electric blocking element and/or a blocking element based on a different blocking principle. 
     In a further preferred embodiment, the second transport arrangement comprises a release element adapted to release the blocking element. 
     In particular, the release element is adapted to release the blocking element before the predetermined time of a time controlled blocking element. The activation of the second transport arrangement, for example, can comprise the activation of the release element, which then in turn releases the blocking element and thus enables the automatic retrieval of the used portion of tissue web by the second transport arrangement. 
     For example, the release element comprises a valve, in particular, an electric valve and/or a solenoid valve, and/or a drive, in particular, an electric drive. 
     For example, the release element can comprise an electrically driven solenoid valve which interacts with, for example, a pneumatic blocking element in order to release it. Preferably, the release element has a low energy consumption and/or is adapted to be battery-supplied. 
     The first transport arrangement can comprise a manual transport mechanism and/or an automatic transport mechanism, in particular, a driven transport mechanism, preferably electrically driven, e.g., via a battery supply and/or other energy supply. A manual transport mechanism for the first transport arrangement preferably is operated by action of a user, only, e.g., by a user pulling the tissue, which preferably leads to a corresponding provision of tissue, e.g., by decoiling and possibly guiding the tissue via rolls to the dispensing opening. Preferably, a manual transport mechanism does not need any energy supply, e.g., in the form of batteries or a power line. 
     The second transport arrangement can comprise a manual transport mechanism and/or an automatic transport mechanism, in particular, a driven transport mechanism, preferably electrically driven, e.g., via a battery supply and/or other energy supply. A manual transport mechanism for the second transport arrangement preferably is independent from, in particular, electric, energy supply, e.g., in the form of batteries or a power line. Preferably, the manual transport mechanism for the second transport arrangement operates by tensioning and releasing a biasing element, such as a spring, and/or via a, preferably mechanical, coupling with the first transport mechanism. 
     For example, the dispenser can be a so-called “non-touch” dispenser where the activation of the first transport arrangement for dispensing a portion of unused tissue is realized without having the user making contact with the dispenser of the tissue. For example, a user&#39;s presence in front of the dispenser can be detected and the first transport arrangement can be activated thereupon. The detection of a user&#39;s presence can be detected, for example, via the detection arrangement described herein and/or via a separate detection unit, which may be specifically adapted for detecting whether a user holds his or her hand in front of a detection area of the dispenser, for example. 
     In a further preferred embodiment the detection arrangement is in an energy-saving sleeping mode by default and preferably is adapted to raise to an active mode upon activation of the first transport arrangement. This embodiment is particularly preferred to save energy consumption. For example, the control unit can be adapted to raise the detection arrangement from the energy saving sleeping mode to an active mode upon activation of the first transport arrangement. Alternatively or additionally, a switch can be provided, for example, a reed switch. Preferably, such a switch is switched upon activation of the first transport arrangement. The switching of the switch preferably results in raising the detection arrangement from energy saving sleeping mode to an active mode. For example, a reed switch can be positioned in the vicinity of the blocking element. A magnet can be positioned on the blocking element such that when the blocking element reaches its blocking position (in particular, when or after the first transport arrangement has been activated), the magnet on the blocking element switches the reed switch and thus initiates the raising of the detection arrangement to the active mode. 
     According to a further preferred embodiment the control unit is adapted to activate the second transport arrangement when a repeated activation of the first transport arrangement by a single user is detected. In practice, situations can arise where a user wants to use more than one portion of tissue web and thus repeatedly activates the first transport arrangement. In such a situation, it is preferred that increasingly large loops, in particular “floor loops,” are avoided. Thus, it is advantageous to detect the repeated activation of the first transport arrangement by the same user, i.e., a repeated activation of the first transport arrangement without detecting a user change, and to activate the second transport arrangement, in particular, for retrieval of the used tissue portion, in such a situation. In addition, maintenance and service calls and costs can be reduced, and the availability of the dispenser for the operator can be increased. 
     Increasingly large loops are heavy and harder to retrieve by the second transport arrangement and thus put additional wear on the second transport arrangement. By providing solutions for avoiding increasingly large loops, the lifespan and reliability of the second transport arrangement can be increased. 
     In a further preferred embodiment the control unit is adapted to activate the second transport arrangement when a departure speed of a user is detected that is above a threshold value, in particular, in case such a departure speed is detected after a certain amount of time has elapsed after a manual activation of the first transport arrangement by a user. 
     When the first transport arrangement is a manual activation mechanism, such as in dispensers where the user actively pulls the tissue web, movements may occur right after the pulling of the tissue by the user that resemble a high departure speed. Therefore, the activation of the second transport arrangement in case of a high departure speed is particularly preferred only after a certain amount of time after a manual activation of the first transport arrangement. 
     Individual or all embodiments relating to the dispenser, in particular, the detection arrangement and/or the control unit, can be combined and have particular advantages, also in the specific combinations. 
     According to a further aspect, it is provided a retrofit kit for a dispenser according to at least one of the preceding claims, the retrofit kit comprising a detection arrangement comprising at least one sensor unit, preferably comprising a first sensor and a second sensor, for detecting a user change a control unit adapted to activate a second transport arrangement of the dispenser when a user change is detected. 
     It is particularly preferred that the retrofit kit comprises a release element adapted to release a blocking element of the second transport arrangement of the dispenser. 
     According to a further aspect, it is provided a method for provision of portions of a tissue web, the method comprising transporting unused tissue and transporting used tissue such that a tissue portion located between a first transport arrangement and a second transport arrangement protrudes through a dispensing opening in a housing of a dispenser, detecting a user change, in particular, with a detection arrangement comprising at least one sensor unit, preferably comprising a first sensor and a second sensor; activating the second transport arrangement when a user change is detected. 
     According to a further aspect, it is provided a method for upgrading a dispenser for provision of portions of a tissue web, the method comprising installing a retrofit kit as described herein in a dispenser for provision of portions of a tissue web, the dispenser comprising a first transport arrangement for unused tissue and a second transport arrangement for used tissue and a housing with a dispensing opening through which a tissue portion located between the first transport arrangement and the second transport arrangement protrudes. 
     As to the advantages, preferred embodiments and details of these further aspects and their preferred embodiments, reference is made to the corresponding advantages, preferred embodiments and details described above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments shall now be described with reference to the attached drawings, in which 
         FIG. 1  shows an example of a wall-mounted dispenser with three users in a high-frequency operating situation; 
         FIG. 2  shows a side view of an example of a dispenser with first and second transport arrangements; 
         FIG. 3  shows examples of two dispensers with two different detection principles; 
         FIG. 4  shows examples of three sensors with three different detection principles; 
         FIG. 5  shows an example of a dispenser in different stages of use and a possible detection principle; 
         FIG. 6  shows a detail of a section of an example of a dispenser with a second transport arrangement and a front slot of a dispensing opening; 
         FIG. 7  shows side views of examples of three dispensers with different positions of sensors having detection fields in different directions; 
         FIG. 8  shows an example of a dispenser over a washbasin; 
         FIG. 9  shows an example of a dispenser with a sensor having a detection field in the direction of a user; 
         FIG. 10 a    shows a further example of a dispenser with a sensor having a detection field in the direction of a user; 
         FIG. 10 b    shows an example of a dispenser with a sensor having a detection field in the direction of a user where three users queue in line; 
         FIG. 11  shows an example of a dispenser with a sensor having a detection field in the direction of the hands of a user; 
         FIG. 12  shows a further example of a dispenser with a sensor having a detection field in the direction of the hands of a user; 
         FIG. 13  shows an example of a dispenser over a washbasin having a detection field in the direction of the hands of a user; 
         FIG. 14  shows an example of a blocking element of a second transport arrangement and a release element; 
         FIG. 15  shows an example of a first schematic set up of a detection arrangement and a control unit; 
         FIG. 16  shows an example of a second schematic set up of a detection arrangement and a control unit; 
         FIG. 17  shows an example of a schematic basic set up of sensors on a printed circuit board; 
         FIG. 18  shows an example of a schematic flow diagram of an activation of the second transport arrangement; 
         FIG. 19  shows two examples of a sensor output evaluation; 
         FIG. 20  shows an example of an evaluation of sensor data of a first sensor; 
         FIG. 21  shows an example of an evaluation of sensor data of a second sensor; 
         FIG. 22  shows an example of a schematic flow diagram of a method for provision of portions of a tissue roll; and 
         FIG. 23  shows an example of a schematic flow diagram of a method for upgrading a dispenser for provision of portions of a tissue web. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     In the figures, elements with the same or comparable functions are indicated with the same reference numerals. 
       FIG. 1  shows an example of a wall-mounted dispenser  1  with three users U in a high-frequency operating situation.  FIG. 2  shows a dispenser  1  in a side view. 
     The dispenser  1  for provision of portions of a tissue web  30  has a first transport arrangement  41  and a second transport arrangement  42 . In the figures, only schematic parts of the first and second transport arrangement  41 ,  42  are shown. Further, the dispenser  1  has a housing  10  with a back part  13 , in particular, for wall mounting the dispenser  1 , and an openable housing cover  11  with a front face  12 . The dispenser  1  further has a dispensing opening  20  comprising a front slot  21  and a back slot  22 . The front slot  21  and the back slot  22  are separated by an intermediate part  14  of the housing  10 . 
     A tissue portion  33  located between the first transport arrangement  41  and the second transport arrangement  42  protrudes through the dispensing opening  20 . The tissue portion  33  protruding through the dispensing opening  20  has the form of a loop, as can be seen in  FIG. 1 , for example. A part  33   a  of the tissue portion  33  faces the user U and a part  33   b  of the tissue portion  33  faces the wall or away from the user. Typically, the part  33   a  of the tissue portion  33  facing the user is unused. The part  33   b  of the tissue portion  33  facing the wall may be used. 
     Preferably, unused tissue  31  is provided in a coiled form as a roll and dispensed through the front slot  21  of the dispensing opening  20  by the first transport arrangement  41 . Once a user U has dried his or her hands, the part  33   b  of the tissue portion  33  facing the wall is retracted through the back slot  22  of the dispensing opening  20  via the second transport arrangement  42  and coiled up to a roll of used tissue  32 . 
     In the next dispensing cycle, when the first transport arrangement  41  is activated and provides tissue web  30  through the front slot  21  of the dispensing opening  20 , the former part  33   a  of the tissue portion facing the user U, which has just been used, becomes the part  33   b  of the tissue portion facing the wall. In this way, the part  33   a  of the tissue portion  33  facing the user U is usually freshly dispensed from the unused tissue  31  through the front slot  21  of the dispensing opening  20  via the first transport arrangement  41 . Once this part  33   a  of the tissue portion  33  has been used and the part  33   b  of the tissue portion  33   b  facing the wall has been retracted through the back slot  22  of the dispensing opening  20  by the second transport arrangement  42 , the former user facing part  33   a  of the tissue portion  33  becomes the new wall facing part of the tissue portion  33   b.    
     The dispenser  1  further comprises a detection arrangement  100  with a sensor unit  120  comprising a first sensor  101  and a second sensor  102  for detecting a user change. Preferably, the detection arrangement can comprise a third sensor  103  and possibly a fourth sensor and possibly further sensor(s). Further, a control unit  50  is provided, which is adapted to activate the second transport arrangement  42  when a user change is detected. Further preferably, the control unit  50  is also adapted to activate the first transport arrangement  41  when a user change is detected. 
       FIGS. 3, 4, and 5  show dispensers  1  with different detection arrangements  100  having at least a first and a second sensor  101 ,  102 , for detecting a user change. For example, the detection arrangement  100  in the left-hand dispenser  1  in  FIG. 3  is arranged at the intermediate part  14  of the housing  10  of the dispenser  1  and adapted to detect movements of the hands H of a user U and the resulting movements of the portion  33  of tissue web  30  protruding from the dispensing opening  20 . On the right-hand side of  FIG. 3 , the detection arrangement  100  of the dispenser  1  is adapted to detect the proximity of a user U or of his or her hand H in front of the sensor  1 . 
     The left-hand dispenser  1  in  FIG. 4  has a detection arrangement  100  comprising a first sensor  101  in the form of a passive infrared sensor for detecting the proximity of a user&#39;s U hand H. In the middle of  FIG. 4 , a dispenser  1  is depicted comprising a second sensor  102  in the form of a capacitive sensor, which is also adapted to detect the presence of a user&#39;s U hands H. On the right-hand side of  FIG. 4 , a dispenser  1  is depicted with a detection arrangement  100  having a third sensor  103  in the form of a time-of-flight (TOF) sensor adapted for detecting a user&#39;s U presence, as well as his or her arrival and/or departure to or from the dispenser  1 . 
       FIG. 5  shows a dispenser  1  with different forms of the portions  33  of tissue web  30  protruding from the dispensing opening  20  during use. On the left-hand side of  FIG. 5  the portion  33  protruding from the dispensing opening  20  of the dispenser  1  is small. In the second depiction of the dispenser  1  in  FIG. 5  the first transport arrangement  42  has been activated by pulling the tissue and the portion  33  protruding from the dispensing opening  20  has increased and clearly shows a user facing part  33   a  and a wall facing part  33   b . In the third depiction of the dispenser  1  in  FIG. 5 , the loop of the portion  33  of tissue web is hanging freely from the dispensing opening  20 . The right-hand side depiction of the dispenser  1  in  FIG. 5  shows a situation similar to the second depiction of the dispenser  1  in  FIG. 5 , where the loop of the portion  33  of the tissue web is tilted towards the right-hand side, which means in the direction towards the user U. In particular, when a user U uses a dispenser  1 , he would draw the loop of the portion  33  of tissue web, in particular, the part  33   a  towards him or her, leading to a situation as depicted in the second and fourth depiction of the dispenser  1  in  FIG. 5 . For the detection of the movement of the tissue, a sensor can be deployed, for example, detecting the varying distance between the user facing part  33   a  of the portion  33  protruding from the dispensing opening  20  and the intermediate portion  14  of the housing, as indicated in the second and third depiction of the dispenser  1  in  FIG. 5 . Alternatively or additionally, the detection arrangement  100  may comprise a sensor  104  depicted on the right-hand side in  FIG. 5 , adapted to detect the position of the wall facing part  33   b  of the tissue portion  33  protruding from the dispensing opening. 
     The individual sensors and detection principles shown herein are preferably combined in a detection arrangement and/or in a sensor unit  120  having at least a first and a second sensor  101 ,  102 , which together produce a combination of sensor signals based on which a change user can be detected. 
       FIG. 6  shows a detail of a section of an example of the dispenser  1  with a roll  41   a  of a first transport arrangement  41  and a front slot  21  of a dispensing opening  20 . A first sensor  101  of a detection arrangement  100  is positioned in the front face  12  of the housing cover  10 . In  FIG. 6 , two different positions of the user facing part  33   a  of the tissue web is shown.  33   a ′ schematically shows the position when a user pulls the user facing part  33   a  of the tissue web.  33   a ″ indicates a situation where the loop of tissue web can hang freely and the front facing part  33   a ″ hangs downward through the front such  21  of the dispensing opening  20 . 
       FIG. 7  shows three dispensers  1  with different positions of sensors  101  having different detection fields  110  oriented in different directions. On the left-hand side, the sensor  101  is positioned at a lower end of the intermediate housing part  14  and has a detection field  110  directed towards the lower end of the user facing part  33   a  of the portion  33  of tissue web protruding from the dispensing opening  20 . In the middle of  FIG. 7 , the sensor  101  is positioned at an upper end of the intermediate housing part  14  and has a detection field  110  directed towards the inner side of the loop of the tissue portion  33 . On the right side of  FIG. 7 , the sensor  101  is located at a lower part of the front face  12  of the housing  10  and has a detection field  110  directed towards a likely position of a user&#39;s U hands H during use of the dispenser  1 . 
       FIG. 8  shows a dispenser  1  with a sensor having a similar detection field  110  as on the right-hand side of  FIG. 7  in a situation where a dispenser  1  is wall-mounted over a washbasin  2 . 
       FIG. 9  shows a dispenser  1  with a detection arrangement having at least one sensor with a detection field  110  in a substantially horizontal direction towards a user U. 
       FIG. 10 a    shows a dispenser  1  having a detection arrangement with at least one sensor having a detection field  110  in the direction of a user U.  FIG. 10 b    shows a similar situation as  FIG. 8  but with a queue of three users U, i.e., a high-frequency situation. 
       FIG. 11  shows a dispenser  1  with a detection arrangement having at least one sensor with a detection field  110  directed towards the likely position of the hands H of a user U during use of the dispenser  1 . 
       FIG. 12  shows a dispenser  1  similar to the dispenser depicted in  FIG. 11  in a top view. 
       FIG. 13  shows a dispenser  1  similar to the dispenser depicted in  FIG. 11 . In  FIG. 13 , additional washroom components are shown, which are common in practice and often pose challenges to the correct detection of a user change, in particular, a washbasin  2  with metallic surface, ceiling mounted elements  3  like heat radiators, light bulbs, or heaters, and underfloor heating  4 . 
       FIG. 14  shows an example of a blocking element  210  of a second transport arrangement  42  and a release element  220 . The blocking element  210  is in the form of a time controlled, mechanical blocking element having a spring  211  and a pneumatic component  212  controlled by a time controlled valve  215 . 
     When the first transport arrangement  41  is activated, the blocking element  210  is moved against the force of spring  211  into its blocking position, where the pneumatic element  212  is brought against the wall  213  having a hole  214 . The pneumatic element  212  is sucked there against and will be released only after a certain amount of time, which is defined by the time controlled valve  215 . For example, the certain amount of time, after which the pneumatic element  212  will be released, can be changed by adjusting or exchanging the time controlled valve  215 . 
     On the other side of the wall  213 , the opening  214  is closed by a closure element  222  connected to a release valve  221  in the form of a solenoid valve. This release element  220  is adapted to release the blocking element  210  by moving the closure element  222  away from the hole  214 . In this way, the pneumatic element  212  relaxes prematurely, i.e., before the determined time of the time controlled valve  215  of the blocking element  210  is over. 
     Once the pneumatic element  212  is released (either after a certain time via the time controlled valve  215  or prematurely via the release valve  221 ), the blocking element  210  moves back into its unblocked position shown on the left-hand side in  FIG. 14  via the force of spring  211 . The detail on the right-hand side on  FIG. 14  shows the blocking element  210  in its blocking position. 
       FIGS. 15 and 16  show examples of schematic setups of a detection arrangement  100  and a control unit  50 . In principle, a retrofit kit  300  as described herein can comprise or consist of such a detection arrangement and a control unit. For example, in  FIG. 15 , a first printed circuit board  51  as well as a second and third printed circuit board  52  and  53  are provided. The first printed circuit board  51  is the main board comprising the central processing unit (CPU) and the batteries and is connected via for spring connectors  54  to the third printed circuit board  53  the which the release valve  221  of the release element  220  and a switch, preferably a magnetic switch  230  are connected to activate the release element. Further, the first printed circuit board  51  is connected to a second printed circuit board  52  housing a sensor  101 , for example, a TOF sensor, and having a detection field  110 . 
       FIG. 16  shows an example where a first sensor  101 , for example, a TOF sensor having a detection field  110 , a second sensor  102 , for example, an infrared sensor having a detection field  110 , and a third sensor  103 , for example, an acceleration sensor, are all located on one single printed circuit board  51  together with the control unit  50 . In this case, on the main printed circuit board the CPU and the battery are also positioned having a detection field  110 . The release valve  221  of the release element is connected to this single printed circuit board  51 . 
       FIG. 17  shows a further example of a printed circuit board with a first sensor, for example, a time of flight sensor  101  with a detection field  110 , a second sensor  102 , for example, in the form of an infrared sensor with a detection field  110 , a third sensor  103 , in the form of an accelerometer. 
       FIG. 18  shows a schematic flow diagram of an example activation of the second transport arrangement. On the right-hand side, the steps related to the blocking element  210  are shown, on the left-hand side the steps related to the detection arrangement  100  are shown. Step  401  depicts the start, which can be the activation of the first transport arrangement. This moves the blocking elements  210  in the blocking position and thereby switches the switch  230 . This leads to the raising of the detection arrangement  100  from energy-saving sleeping mode to an active mode in step  403 . In the following steps, the sensors of the detection arrangement  100  are detecting whether the user change takes place or not. Firstly, in step  404  it is detected whether a user is present in front of the dispenser. In step  408  the value is stored in case a user is present in front of the sensor. In step  406  it is determined whether the user moves away from the sensor. This is done as long as the user does not move away. As soon as the user does move away, the release element is activated in step  407  and the blocking element  210  is released. Subsequently, in step  408 , the detection arrangement goes back into energy-saving sleeping mode. 
     Further, after step  403  and parallel to step  404 , a timer countdown is started in step  409 , wherein in step  410  a time value can be set for this timer countdown. This timer countdown preferably corresponds to the predetermined time of the time controlled locking element  210 . Step  411  checks whether the timer has counted down to zero. Once the timer is counted down to zero, the detection arrangement  100  is also put into energy-saving sleeping mode again, possibly without activating the release element in step  407 , in case the timer has counted down to zero before a user change has been detected in steps  404 ,  406 , and  408 . 
       FIG. 19  shows an example of two different sensor outputs over time. For the reliability and accuracy of the detection of a user change it is advantageous when the sensor output gives a clear indication of an event to be detected. In the left-hand example of  FIG. 19 , the sensor signal indicates the use of the dispenser when the sensor output is larger than a threshold for certain period of time. On the right-hand side of  FIG. 19 , a use is detected when the sensor output, for example, resembling a proximity of a user, is below a certain threshold for certain period of time. Sensors are preferred, which produce a reliable sensor signal allowing to indicate an event in a very short amount of time, i.e., having a short response time. 
       FIGS. 20 and 21  show examples on how sensor signals can be interpreted for further assessment, in particular in order to have the control unit act upon detected events. In  FIG. 20 , the line S shows the sensor signal indicating the end of usage, and line I shows the interpretation thereof that the user is out of range.  FIG. 21  shows with S 1  a peak in the sensor signal indicating that a new tissue portion is released and a second peak S 2  that the tissue portion is swinging. The vertical portion in dashed line I shows the interpretation of the end of usage. 
       FIGS. 22 and 23 , finally, show schematic flow diagrams of the following methods. 
       FIG. 22  shows a method  1000  for provision of portions of a tissue web, the method comprising transporting  1001  unused tissue and transporting used tissue such that a tissue portion located between a first transport arrangement and a second transport arrangement protrudes through a dispensing opening in a housing of a dispenser, detecting  1002  a user change; activating  1003  the second transport arrangement when a user change is detected. 
     The method  2000  for upgrading a dispenser for provision of portions of a tissue web, depicted in  FIG. 23  comprises installing  2001  a retrofit kit  300  in a dispenser for provision of portions of a tissue web, the dispenser comprising a first transport arrangement for unused tissue and a second transport arrangement for used tissue and a housing with a dispensing opening through which a tissue portion located between the first transport arrangement and the second transport arrangement protrudes.