WO2025036545A1

WO2025036545A1 - Low-power level sensor for hygiene consumable

Info

Publication number: WO2025036545A1
Application number: PCT/EP2023/072287
Authority: WO
Inventors: Anders Lundqvist
Original assignee: Essity Hygiene and Health AB
Current assignee: Essity Hygiene and Health AB
Priority date: 2023-08-11
Filing date: 2023-08-11
Publication date: 2025-02-20
Anticipated expiration: 2026-02-11

Abstract

A sensor arrangement for detecting a filling state of a reservoir of a hygiene consumable comprising a set of sensors arranged along a depletion direction of the reservoir, each sensor being configured to detect presence of hygiene consumable in its respective proximity, and a processing section being coupled to said set of sensors for obtaining a presence detection from individual sensors of said set of sensors, wherein the processing section is configured to obtain start information indicating an individual sensor to be used as a start sensor, address the sensor indicated by the start information and obtain a first presence detection result from the addressed sensor, if the first presence detection result indicates no presence of hygiene consumable, address a subsequent sensor arranged downstream relative to the previously addressed sensor and in the depletion direction, and obtain a subsequent presence detection result from the addressed sensor, and, if the subsequent presence detection result indicates presence of hygiene consumable, store information indicating the addressed subsequent sensor as the start information.

Description

LOW-POWER LEVEL SENSOR FOR HYGIENE CONSUMABLE

Technical field

The present invention relates to detecting a filling level of a reservoir of a hygiene consumable, such as soap, disinfectant , tissue , towel , and the like . In particular, the present invention relates to power consumption in a level sensor for a hygiene consumable in a piece of hygiene equipment such as a dispenser of that consumable .

Background

The benefits of proper hygiene , in particular in the form of hand hygiene , are widely acknowledged . It is commonplace that public or commercial facilities such as washrooms in public buildings , of fices , restaurants , airports , hospitals , shopping malls and so on are normally provided with dispensers for various hygiene consumables , for example paper towels , liquid soap, disinfectant , tissues , toilet paper, or sanitary napkins .

Such consumables are normally stored in dispensers , which may be fixedly located at suitable positions in the washroom or other locations . A dispenser can for example be in the form of a holder for paper towels or tissues , a holder for toilet paper, a holder for diapers , or a container for liquid soap, disinfectant or other consumable . Further, also used items , such as towels or tissues , may still be considered as a hygiene consumable and respective equipment for receiving such used consumables may be waste bins or other receptacles for receiving and containing such used consumables .

In the above context it is oftentimes desirable to know about the filling level of a piece of hygiene equipment such as a dispenser or waste bin . Usually, knowledge on the filling state is desired in order to initiate and plan the refilling of dispensers , emptying bins or other receptacles , or other service activities . For this purpose , it is already known to provide said hygiene equipment with level sensors that are configured to measure and report a filling state of the respective consumable . Such sensors are usually provided with a sensor arrangement that can detect a measured figure that relates to the filling state ( such as a distance , weight , presence , and the like ) , and some kind of logging and/or reporting function that provides the relevant information to an applicable service entity . For example , the sensors report respective filling states to a service center from which refi lls or replacements can be initiated .

However, such sensors are oftentimes battery powered or employ energy harvesting techniques ( such as solar cells ) and thus the available power may be limited . As sensors should at the same time provide a reliable , in terms of both measurement quality as well as responsiveness , measurement output for allowing a high- quality management of the hygiene equipment , the mitigation of responsiveness and power management can be challenging .

There is therefore a need for an improved sensor arrangement for detecting a filling state of a hygiene consumable that can be employed in hygiene equipment that provides high quality output at less power consumption . In other words , there is a need for sensor arrangements that operate longer or more often with the respectively available power resources , whilst providing reliable and responsive information on the filling state . Summary

The mentioned problems are solved by the subj ect-matter of the independent claims . Further preferred embodiments are defined in the dependent claims .

According to an aspect of the present invention, there is provided a sensor arrangement for detecting a filling state of a reservoir of a hygiene consumable comprising a set of sensors arranged along a depletion direction of the reservoir, each sensor being configured to detect presence of hygiene consumable in its respective proximity, and a processing section being coupled to said set of sensors for obtaining a presence detection from individual sensors of said set of sensors , wherein the processing section is configured to ( a ) obtain start information indicating an individual sensor to be used as a start sensor, (b ) address the sensor indicated by the start information and obtain a first presence detection result from the addressed sensor, ( c ) i f the first presence detection result indicates no presence of hygiene consumable , address a subsequent sensor arranged downstream relative to the previously addressed sensor and in the depletion direction, and obtain a subsequent presence detection result from the addressed sensor, and ( d) i f the subsequent presence detection result indicates presence of hygiene consumable , store information indicating the addressed subsequent sensor as the start information .

According to an aspect of the present invention, there is provided a piece of hygiene equipment for dispensing and/or receiving a hygiene consumable , comprising a sensor arrangement according to one of the disclosed embodiments .

According to a method aspect of the present invention, there is provided a method of operating a piece of hygiene equipment , such as a dispenser for a hygiene consumable , or a sensor arrangement according to one of the disclosed embodiments for detecting a filling state of a reservoir of a hygiene consumable . The method embodiments are speci f ically provided for detecting a filling state of a reservoir of a hygiene consumable by employing a sensor arrangement comprising a set of sensors arranged along a depletion direction of the reservoir, each sensor being configured to detect presence of hygiene consumable in its respective proximity, the method comprising the steps of : a ) obtaining start information indicating an individual sensor to be used as a start sensor ; b ) addressing the sensor indicated by the start information and obtaining a first presence detection result from the addressed sensor ; c ) i f the first presence detection result indicates no presence of hygiene consumable , addressing a subsequent sensor arranged downstream relative to the previously addressed sensor and in the depletion direction, and obtaining a subsequent presence detection result from the addressed sensor ; d) i f the subsequent presence detection result indicates presence of hygiene consumable , storing information indicating the addressed subsequent sensor as the start information .

Brief Description of the Drawings

Embodiments of the present invention, which are presented for better understanding the inventive concepts and which are not to be seen as limiting the invention, will now be described with reference to the Figures in which :

Figures 1A and IB show general device embodiments o f the present invention for a sensor arrangement detecting a filling state of a reservoir of a hygiene consumable ;

Figures 2A to 2 F show di f ferent types of hygiene equipment in which a filling state of a reservoir of a hygiene consumable is detected according to embodiments of the present invention;

Figures 3A and 3B show general measuring concepts involved in detecting a filling state of a reservoir of a hygiene consumable according to embodiments of the present invention;

Figure 4 shows a schematic view of a sensor arrangement according to a further embodiment of the present invention; and

Figures 5A to 5C show flow charts of general method embodiments of the present invention .

Detailed description

Figures 1A and IB show general device embodiments of the present invention for a sensor arrangement detecting a filling state of a reservoir of a hygiene consumable . While Figure 1A shows a modular example of such a sensor arrangement , Figure IB focusses on the functional elements at a more general level . The reference numerals are however used for the same elements in both depictions . According to embodiments of the present invention, there is provided a sensor arrangement 10 for detecting a filling state of a reservoir of a hygiene consumable comprising . The sensor arrangement 10 comprises a set of sensors 110- 1 , 110-2 , ... 110-n, arranged along a depletion direction D of the reservoir that is subj ect to filling state monitoring . Generally, the mentioned reservoir may form part of a piece of hygiene equipment and holds a supply of the hygiene consumable ( e . g . paper towels , soap, etc . ) . During use the supply diminishes and the reservoir correspondingly depletes . This is assumed to happen along a speci fic direction which is indicated with the so-called depletion direction . For example , a stack of paper towels is depleted whilst one end of the stack moves along that depletion direction .

Each sensor 110- 1 , 110-2 , ... 110-n, is configured to detect presence of hygiene consumable in its respective proximity . In this way, a filling state can be derived from information that indicates what sensor (s) of the set of sensors "see" consumable (i.e. detect presence) and what sensor (s) of the set of sensors do not "see" consumable (i.e. do not detect presence or detect absence) . For this purpose, the set of sensors are arranged along the depletion direction. Further details on measuring presence of consumable are provided elsewhere in the present disclosure and specifically also in conjunction with Figures 3A & 3B.

The sensor arrangement 10 further comprises a processing section 120 that is coupled to said set of sensors 110-1, 110-2, ... 110- n for obtaining a presence detection from individual sensors thereof. The sensor arrangement 10 may further comprise a memory 130 storing data related to the measurement and reporting process, including program data for instructing the processing section 120 to perform one or more of the actions and functionalities as described elsewhere in the present disclosure. The sensor arrangement 10 may further comprise a communication section 140 for accessing remotely stored data or information and/or forward an report on any measured or determined figure to a network 160, such as the "Cloud" or the Internet. The sensor arrangement 10 may further comprise a battery or other power supply 150 in the form of any one of a battery cell, a rechargeable battery, a super-capacitor, an energy harvesting device, a solar or light cell, a e/m-wave receiver, and the like.

According to the embodiments of the present invention, the processing section 120 is configured to obtain start information indicating an individual sensor to be used as a start sensor. This action may be performed prior to other actions in a potentially repetitive sequence of actions and is thus also referred to as "a)". In this way, the processing section 120 determines with which one of the sensors of the set of sensors 110-1, 110-2, ... 110-n it is to be proceeded. In other words, the processing unit 120 determines a specific one of the sensors to address and drive for a measurement. The fact, that there is a determination of a specific one of the sensors may allow for employing the available, but probably limited, power resources efficiently. However, the start information may change over time and indicate another sensor at a later point in time as compared to an initial or earlier state . Further, initial start information may initially indicate a sensor which may be not the most ef ficient to address as that in point in time . However, as the remaining actions follow, and full sequences of all actions may be repeated one or more times , the start information may indicate an individual sensor which is actually more ef ficient or even most ef ficient to be used as a start sensor, i . e . as the start of the current sequence of actions .

The processing section 120 is further configured to address the sensor indicated by the start information and obtain a first presence detection result from the addressed sensor, which is also referred to as action "b ) " . Speci fically, the processing section addresses the sensor that was selected in the previous action a ) . This may involve providing power (voltage and current ) to the addressed sensor, sending an activation/enabling signal to that sensor, and/or reading an output from that sensor by, for example , performing signal processing such as analogue-to- digital conversion (ADC ) and or other signal level parsing . The latter all employ power resources which may need to be provided by a local ( and quite limited) power supply such as the mentioned battery 150 . It is noted that each such addressing thus involves power consumption and the fact that a speci fic one of the sensors is selected and addressed may very much contribute to power ef ficiency of the presented sensor arrangement .

The processing section 120 is further configured to determine whether the first presence detection result indicates no presence of hygiene consumable . In other words , it is checked whether the j ust addressed sensor provides a measurement output that indicates that there is no presence of hygiene consumable which is basically equivalent to the situation that the reservoir is empty and carries no supply of the consumable at least in the area or section being monitored by the addressed sensor . I f the first presence detection result indicates no presence of hygiene consumable , the processing section 120 is configured to address a subsequent sensor arranged downstream relative to the previously addressed sensor and in the depletion direction and to obtain a subsequent presence detection result from the addressed sensor . As the sensors are arranged along the direction along the reservoir depletes , the so selected next sensor is , from the current point of view, the most likely sensor to detect presence . For example , i f at this point in time the subsequent sensor detects presence of consumable , the filling state can be determined quite ef ficiently by only addressing two sensors which may be anyway the minimum number of sensors . The set of actions including determining whether the first presence detection result indicates no presence and addressing and reading out accordingly the subsequent sensor, is also referred to as action "c ) " .

The processing section 120 is further configured to determine whether the subsequent presence detection result indicates presence of hygiene consumable . I f so , the processing section 120 is configured store information indicating the addressed subsequent sensor as the start information (which is also referred to action "d) " ) . This relates to the minimum case where one sensor showed no presence whi le an adj acent and subsequent showed presence of the hygiene consumable , and precise knowledge on the filling state is obtained by addressing only two sensors and thus consuming also only the power needed to address these two sensors . The start information is updated accordingly, which allows the sensor arrangement in the next sequence to consider the sensor output history and even skip the addressing of the previously valid start sensor, i . e . in the next sequence only one sensor need to be addressed as long as this yields presence of the consumable . At a time when the supply in the reservoir has further depleted, the transition to a "next" subsequent sensor may be necessary but even this transition would only require the addressing of two sensors . In all , a monitoring scheme is obtained that addresses only the minimum number of sensors and thus substantially saves power so that the power supply may provide in all a longer operation time .

In case the optimum pair of sensors , i . e . one that indicates no presence and an adj acent one that indicates presence of consumable , has not yet been found, the processing section can proceed as follows . Speci fically, the processing section may be configured to , i f the subsequent presence detection result indicates no presence of hygiene consumable , address a subsequent sensor arranged downstream relative to the previously addressed sensor and in the depletion direction, obtain a subsequent presence detection result from the addressed sensor, repeat said addressing and obtaining as long as the subsequent presence detection result indicates no presence of hygiene consumable , and, i f the subsequent presence detection result indicates presence of hygiene consumable , store information indicating the addressed subsequent sensor as the start information .

Generally, an addressing of a sensor may include to select one of the set of sensors by means of setting a stored value to a respective value . For example , the processing unit may employ a memory for storing a pointer value that indicates what speci fic one of the set of sensors is to be activated and driven and/or from what speci fic one of the set of sensors a measurement value is to be acquired . This pointer value may be independent from any measurement process or result , so that it may remain unchanged even i f an indicated sensor has already been activated, driven and a measurement value has been acquired from it . In this way, the addressed sensor may be identi fied as a "current" sensor to which the information or pointer may point to still at a later point in time for inferring a filling state . That may mean that a currently or previously addressed sensor may change dynamically with a linear counter/pointer changing correspondingly . Further, it may be provided that two sensors in a row, i . e . adj acent sensors , need to yield a measurement result indicating no presence of hygiene equipment in order to confirm such a state for obtaining a higher degree of reliability . Further, the start sensor may be identi fied as a default start sensor, by means of a respectively provided default value for initiating the embodiments of the present invention at a most suitable position .

The processing section can be further configured to repeat said addressing and obtaining as long as the subsequent presence detection result indicates no presence of hygiene consumable and as long as a last sensor at an end of the depletion direction is not reached . In this way, an iterative approach is provided for searching for the two sensors that clearly indicate the filling state of the reservoir, as one indicates no presence of consumable and an adj acent one indicates presence of consumable . Naturally, there can also be the case that the reservoir is fully depleted and that accordingly no one sensor of the set of sensors will indicate presence of hygiene consumable . For this case , the processing section may be configured to determine that the reservoir is in an empty state i f the last sensor at the end of the depletion direction is addressed and a detection result from the addressed sensor indicates no presence of hygiene consumable .

In other situations , the initial action a ) may yield presence of hygiene consumable . This may be the case when a previous sequence has already determined the filling state and the reservoir has since then not depleted enough to be detected by the set of sensors with their given granularity ( i . e . number of sensors per unit length along the depletion direction) . Further reasons may include that the default attempt did not start at a suitable position or whenever a refill of the reservoir has taken place . Especially in the latter, it is appropriate to search for a new filling state and the involved power consumption may be well invested . Speci fically, the processing section may then be further configured, i f the first presence detection result indicates presence of hygiene consumable , address a subsequent sensor arranged upstream relative to the previously addressed sensor and in the depletion direction, obtain a subsequent presence detection result from the addressed sensor, repeat said addressing and obtaining as long as the subsequent presence detection result indicates presence of hygiene consumable .

For the above case , the processing section is further configured, i f the subsequent presence detection result indicates no presence of hygiene consumable , store , as the start information, information indicating the sensor addressed before the addressed subsequent sensor . In this way, a new optimum start position can be set for considering the situations of a refill of the reservoir, i . e . in situation in which the reservoir' s supply changed, possibly also relatively abruptly, against the "usual" depletion direction .

Further, the processing section may be configured to repeat said addressing and obtaining as long as the subsequent presence detection result indicates presence of hygiene consumable and as long as a first sensor at a beginning of the depletion direction is not reached . This would in any way correspond to situations in which the reservoir is filled completely so that every sensor of the set of sensors would detect presence of hygiene consumable in the reservoir . Especially then the processing section can be further configured to determine that a refill of the reservoir has taken place i f the first presence detection result indicates presence of hygiene consumable . I t is noted that the mentioned first sensor refers to a sensor which is at an end of the set of sensors , so there will be no further sensor available beyond that sensor . For example , such a first sensor may be identi fied by sensor 110- 1 in the configuration as shown in Figure 1A.

The processing section can be further configured, to store information indicating the filling state of the reservoir of the hygiene consumable on the basis of and/or in relation to the stored start information . For example , information can be stored that allows for determining a measured filling state to some degree of precision or resolution ( e . g . in steps of 10% of a maximum capacity of the reservoir ) or to at least make conclusions on a more general level , such as determining that a refill is necessary or advisable . In the latter case , it may be suf ficient that the information indicates a fact that the fil ling state has decreased below some threshold that is to trigger a refill . The information indicating the filling state can be thus stored on the basis of the stored start information that , in turn, would indicate such situations including the need for refill . Likewise , the information indicating the filling state can also be stored in relation to the stored start information, in the sense that the stored start information indicates a particular sensor, which, in turn, indicates to a particular filling state , as the sensor' s position is more or less well defined along the depletion direction . For example , there may be 10 sensors in the set of sensors arranged equidistantly along the depletion direction over the depletion span . A sensor position or number may thus relate to the filling state in steps of a tenth of the reservoir capacity .

The processing section may be further configured to compile a reporting message on the basis of the information indicating the filling state . For example , a message may be compiled that can inform a remote entity ( e . g . network server, control centre , and the like ) about the filling state directly or already at a more general level of merely indicating a necessary action such as a refill . The processing section may for example instruct and/or control the communication section 140 to convey the compiled reporting message toward a network 160 .

As already mentioned, the embodiments of the present disclosure consider a continuous approach in which the individual actions a ) through d) are repeated from time to time in order to determine the filling state and to take into account the depletion of the reservoir in use . In one embodiment , the processing section may be speci fically configured to repeat the actions a ) through d) periodical ly and to decrease the time period in relation to the filling state . In other words , the measurements are performed more often as the reservoir depletes . In this way, energy resources can be saved as long as a need for refill is less likely as the reservoir is still relatively full , whilst the responsiveness is increased once a need for a refill becomes more likely . Especially for high quality of service applications , such an approach may contribute to initiating a refill in time and avoiding situations in which the necessity for a refill is unnoticed .

The sensor arrangement 10 further comprises a housing 100 which may accommodate at least some elements , such as the sensors 110- I and the processing section 120 . The housing may be in a speci fic form comprising an elongate housing bar 101 that accommodates the set of sensors . In this way, a modular configuration of the sensor arrangement 10 can be obtained which can be handled easily for installation and servicing in the respective application of a piece of hygiene equipment , whilst reliably spanning the extension of the reservoir for providing sensors at relative positions .

Figures 2A to 2 F show di f ferent types of hygiene equipment in which a filling state of a reservoir of a hygiene consumable is detected according to embodiments of the present invention . Figure 2A shows a schematic view of a dispenser 1- 1 that is arranged to dispense a hygiene consumable in a liquid form . For example , this may be a soap dispenser or a dispenser for a disinfectant such as alcohol or alcogel . Predominantly for such a dispenser type the depletion direction D will be from the top to the bottom as the supply of the consumable will accumulate toward the bottom . The measured figure may be in relation to a top surface of the supply and a maximum height of the reservoir . A sensor arrangement 10 as described in the respective embodiments of the present disclosure may be arranged as shown .

Figure 2B shows a schematic view of a dispenser 1-2 that is arranged to dispense a hygiene consumable such as a tissue or paper towel 2 . The dispenser 1-2 has a reservoir 200 with a given supply 20 of hygiene consumable , in the present exemplary case a stack of paper towels 2 . A user can take one towel from an opening on a bottom side 19 of the dispenser 1-2 , which will make the reservoir 200 gradually deplete in the depletion region D as the supply 20 diminishes . A sensor arrangement 10 as described in the respective embodiments of the present disclosure may be arranged as shown .

Figure 2C shows a schematic view o f a similar dispenser 1-3 that is arranged to dispense a hygiene consumable such as a tissue or paper towel . The shown case may be similar to that shown and described in conj unction with Figure 2B except for the depletion direction D being from the bottom to the top . Namely, there exist tissue dispensers that push a supply upwards so that a user can pull out one or more towels/ tissues from the top . Mechanical spring action may be involved to push up the tissue supply as consumables are dispensed . This configuration may provide the opportunity for measuring a distance between a sensor position and the position of a well-defined element such as the support that pushes the consumable supply upwards . In this way, the sensor ( e . g . TOF or light ref lection/absorption) may be more independent from the consumable as such as measurement do not depend on optical or other physical properties of the consumable . A sensor arrangement 10 as described in the respective embodiments of the present disclosure may be arranged as shown .

Figure 2D shows a schematic view of a dispenser 1-4 that is arranged to dispense a hygiene consumable such as a tissue or paper towel 2 ' . In this case , the consumable is an endless towel supply 2 ' which may have perforations in between individual towels to be dispensed . Namely, a user can pull on the supply from the bottom side 19 of dispenser 1-4 in which the supply is led upwards and then again over one or more rolls 18 again downwards ( see partial cut outs of the dispenser front and the supply moving downwards ) . The dispenser 1-4 has again a reservoir 200 with a given supply 20 ' of hygiene consumable , in the present exemplary case an endless concatenation of paper towels 2 ’ . Taking one towel from an opening on that bottom side 19 of the dispenser 1-4 will make the reservoir 200 gradually deplete in the depletion region D as the supply 20 ' diminishes . It is noted that in this regard the behaviour is similar to the dispenser 1- 2 described in conj unction with Figure 2B, although the consumable will first move upwards and then downwards . Speci fically, a sensor arrangement 10 as described in the respective embodiments of the present disclosure may be arranged in dispenser 1-4 and would operate j ust as in the case of dispenser 1-2 . For this , it may be provided that the paper 2 ’ moves upwards and downwards relatively close to the front and rear dispenser housing wall , whereas the sensor 10 is arranged substantially there in between .

Figure 2E shows a schematic view of a dispenser 1-5 that is arranged to dispense a hygiene consumable in the form of a roll , such as toilet paper . In such types , a diameter of the roll can act as an end or limit of the supply, whereas the position of the sensor may be again a fixed point for any distance measurements . It is noted that this concept may apply to both types of roll dispensers , namely rolls that supply from the outside ( depletion direction D, distance to be considered between outer roll diameter and sensor position) as well as rolls that supply from the inside ( depletion direction D' , distance to be considered between inner roll diameter and sensor position) . A sensor arrangement 10 as described in the respective embodiments of the present disclosure may be arranged as shown .

Figure 2 F shows a schematic view o f a piece of hygiene equipment in the form of a waste bin 1- 6 that is arranged to receive a used hygiene consumable in the form of towels , tissues , and the like . In such types , the reservoir is for used consumables and the filling state will increase over time rather than decrease as is the case for the earlier discussed types of hygiene equipment . A full reservoir is then an indication for the need of emptying the bin or replacing a full bin liner with a new one . However, the general concepts of the present invention naturally apply accordingly . Especially, also any considerations relating to a filling state and a depletion direction, in that the reservoir is seen as free capacity to receive further used consumables . Thus , during use of a piece of hygiene equipment of that type the reservoir will al so deplete along a depletion direction, as , for example , the reservoir for holding additional material will deplete upwards , and as shown with the depletion direction D in Figure 2 F, while the bin is in use . A sensor arrangement 10 as described in the respective embodiments of the present disclosure may be arranged as shown .

Figures 3A and 3B show general measuring concepts involved in detecting a filling state of a reservoir of a hygiene consumable according to embodiments of the present invention . In Figure 3A there is shown a sensor arrangement 10 with a set of sensors arranged along the depletion direction D of the reservoir 200 . In such a configuration, each sensor 110 is configured to detect presence of hygiene consumable in its respective proximity . This may be implemented by means of light sensors that produce a distinguishable output in relation to whether or not there is supply of consumable next to it ( i . e . in the respective vicinity) . In the shown example , the sensor can emit light and measure a reflected signal , which may be reflected at a reflection point R of an inner wall of the reservoir or the piece of hygiene equipment . As the consumable 20 has already depleted in the reservoir, a sensor 110-A will detect a reflected light signal R which would be equivalent to detecting no presence of consumable 20 in the vicinity of sensor 110-A. On the other hand, the light path for a subsequent sensor 110-B (hidden) may be blocked by the consumable so this sensor would not detect any, or detect only attenuated reflection, which would be in turn equivalent to detecting presence of consumable . It is noted that this concept could also be modi fied to interpret a reflected light as presence and no reflection as absence i f the consumable reflects the probe signal while empty reservoir does not .

In Figure 3B there is shown a sensor arrangement 10 ' with a set of sensors arranged along the depletion direction D of the reservoir 200 . This embodiment considers sensors 110 ' that detect presence of consumable in their respective proximity by means of an interaction I , which can be any one of capacitive coupling, electromagnetic coupling, RADAR, Infrared and other applicable probing techniques . Speci fically, the sensor may be any one of a light barrier sensor, a reflection sensor, a proximity sensor, a capacitive sensor, and the like . This Figure also shows the general concept of a depletion span along the depletion direction D which can range from a full level F to an empty level E . A current supply level S may be determined, at least to some degree of precision, by means of the embodiments of the present invention in a power ef ficient manner .

Figure 4 shows a schematic view of a sensor arrangement according to a further embodiment of the present invention . Speci fically, there is shown at least a sensor section 101" of a sensor arrangement 10" which is the relevant part that accommodates the set of sensors 110"- l , 110"-2 , ..., 110"- 6 , 110"-7 . In this embodiment , the sensors 110"-i are again arranged along a depletion direction including a depletion range starting at some full level F and ending at some empty level E . However, the sensors 110"-i are arranged at a smaller distance dE to each other toward the end E of the depletion direction D as compared to the distance dF to each other toward the start F of the depletion direction D . In this way, measurements are finer or have a higher resolution as the reservoir depletes . In this way, a relatively coarse measurement ( and mapping between sensor and filling state ) can be accepted when a need for refill is less likely as the reservoir is still relatively full , whilst the precision is increased once a need for a refill becomes more likely .

Figure 5A shows a flow chart of a general method embodiment of the present invention . This method is for operating a sensor arrangement for detecting a filling state of a reservoir of a hygiene consumable . The sensor arrangement may comprise a set of sensors arranged along a depletion direction of the reservoir, each sensor being configured to detect presence of hygiene consumable in its respective proximity, and a processing section being coupled to said set of sensors for obtaining a presence detection from individual sensors of said set of sensors , which have been explained in some greater detail elsewhere in the present disclosure .

The method steps can be generally performed by means of the processing section which may employ remote and/or local processing and memory resources such as a microprocessor or an interface to cloud computing . The steps performed include a step S 100 of obtaining start information indicating an individual sensor to be used as a start sensor ; a step S200 of addressing the sensor indicated by the start information and obtain a first presence detection result from the addressed sensor, and a determining step S300 whether the first presence detection result indicates no presence of hygiene consumable . I f determined as YES , i . e i f the first presence detection result indicates no presence of hygiene consumable , the method proceeds to a step S400 addressing a subsequent sensor arranged downstream relative to the previously addressed sensor and in the depletion direction, and obtain a subsequent presence detection result from the addressed sensor . In a step S500 it is determined whether the subsequent presence detection result indicates presence of hygiene consumable . I f determined as YES , i . e . i f the subsequent presence detection result indicates presence of hygiene consumable , the method proceeds to a step S 600 of storing information indicating the addressed subsequent sensor as the start information .

Figure 5B shows a flow chart of a further method embodiment of the present invention . Speci fically, the method may continue from step S300 of Figure 5A i f the determining S300 is not YES , i . e . i f presence of hygiene consumable is determined . The method may then proceed to a step S310 of addressing a subsequent sensor arranged upstream relative to the previously addressed sensor and in the depletion direction . This may comprise altering, e . g . decrementing, a pointer value so that during subsequent executions of that step S310 , the method will address step by step all the sensors that come upstream . After step S310 , the method will proceed to a step S320 of obtaining a subsequent presence detection result from the addressed sensor, and a determining step S330 whether the subsequent presence detection result indicates no presence of hygiene consumable . I f determined NO in step S330 the method comprises a repeating of said addressing step S310 and obtaining step S320 as long as the subsequent presence detection result indicates presence ( logically equivalent to a result "NO" of determining "no presence" ) of hygiene consumable . I f determined YES in step S330 the method may comprise a step S340 of storing information indicating the addressed subsequent sensor as the start information .

Figure 50 shows a flow chart of a further method embodiment of the present invention . Speci fically, the method may continue from step S500 of Figure 5A i f the determining S500 is not YES , i . e . i f no presence of hygiene consumable is determined . The method may then proceed to a step S510 of addressing a subsequent sensor arranged downstream relative to the previously addressed sensor and in the depletion direction . This may comprise altering, e . g . incrementing, a pointer value so that during subsequent executions of that step S510 , the method will address step by step all the sensors that come downstream . After step S510 , the method will proceed to step S520 of obtaining a subsequent presence detection result from the addressed sensor . I f in step S530 no presence of hygiene consumable is determined, then the method proceeds to repeating the addressing S510 and obtaining S520 as long as the subsequent presence detection result indicates no presence of hygiene consumable . However, i f in step S530 presence of hygiene consumable is determined, i . e . i f the subsequent presence detection result indicates presence of hygiene consumable , then the method proceeds to a step S540 of storing information indicating the addressed subsequent sensor as the start information .

Generally, any method and operation schemes according to the disclosed embodiments may comprise a check whether or not the addressing of or the search for a subsequent sensor - either upstream or downstream - has reached a last sensor in the corresponding direction, upstream or downstream along the depletion direction . In other words , an extremum check may be provided for considering the circumstance that there is a first , or extremum sensor at the beginning of the depletion direction and a last , or extremum sensor at the end of the depletion direction . For example and referring to Fig . 1A, a current sensor may be sensor 110-2 and a subsequent sensor may be addressed upstream, i . e . sensor 110- 1 . The mentioned extremum check may in this case yield the result that a subsequent sensor in the upstream direction can be addressed ( and read put as described in the context of the present disclosure ) . However, the sequence may start already at the first sensor 110- 1 and addressing a subsequent sensor upstream is not possible as there is none . In this case , the extremum check may yield the result that there i s no subsequent sensor to be addressed and that the start information to be stored remains unchanged . As for the extremum sensors , storing additional information, e . g . in the form of flags or Booleans , may be considered that account for reaching such extremum sensors . For example , detecting presence at sensor 110- 1 would initially result in looking for a subsequent sensor upstream . As this is not possible , the information may be set so as to indicate that the first sensor indicates presence and thus the reservoir can be considered to be maximally full . A similar way may apply for the last extremum sensor 110-n, i f this yields no presence . In this case , it can be considered that the reservoir is empty .

The above-mentioned extremum checks may be considered as embodiments of the more general definition of repeating the addressing and obtaining as long as the subsequent presence detection result indicates no presence of hygiene consumable and as long as a last sensor at an end of the depletion direction is not reached and repeating the addressing and obtaining as long as the subsequent presence detection result indicates presence of hygiene consumable and as long as a first sensor at a beginning of the depletion direction is not reached . Speci fically, a mentioned extremum check can be considered before any one of steps S 100 , S200 , S400 , S310 , S320 , S510 , S520 , and/or after "NO" in step S330 , and/or after "NO" in step S530 .

Although detailed embodiments have been described, these only serve to provide a better understanding of the invention defined by the independent claims and are not to be seen as limiting .

Claims

Claims :

1 . A sensor arrangement for detecting a filling state of a reservoir of a hygiene consumable comprising : a set of sensors arranged along a depletion direction of the reservoir, each sensor being configured to detect presence of hygiene consumable in its respective proximity, and a processing section being coupled to said set of sensors for obtaining a presence detection from individual sensors of said set of sensors , wherein the processing section is configured to : a ) obtain start information indicating an individual sensor to be used as a start sensor ; b ) address the sensor indicated by the start information and obtain a first presence detection result from the addressed sensor ; c ) i f the first presence detection result indicates no presence of hygiene consumable , address a subsequent sensor arranged downstream relative to the previously addressed sensor and in the depletion direction, and obtain a subsequent presence detection result from the addressed sensor ; d) i f the subsequent presence detection result indicates presence of hygiene consumable , store information indicating the addressed subsequent sensor as the start information .

2 . The sensor arrangement according to claim 1 , wherein the processing section is further configured to , i f the subsequent presence detection result indicates no presence of hygiene consumable , address a subsequent sensor arranged downstream relative to the previously addressed sensor and in the depletion direction, obtain a subsequent presence detection result from the addres sed sensor, repeat said addressing and obtaining as long as the subsequent presence detection result indicates no presence of hygiene consumable , and, i f the subsequent presence detection result indicates presence of hygiene consumable , store information indicating the addres sed subsequent sensor as the start information .

3 . The sensor arrangement according to claim 2 , wherein the processing section is further configured to repeat said addressing and obtaining as long as the subsequent presence detection result indicates no presence of hygiene consumable and as long as a last sensor at an end of the depletion direction is not reached .

4 . The sensor arrangement according to claim 3 , wherein the processing section is further conf igured to determine that the reservoir is in an empty state i f the last sensor at the end of the depletion direction is addressed and a detection result from the addres sed sensor indicates no presence of hygiene consumable .

5 . The sensor arrangement according to claim 1 , wherein the processing section is further configured, i f the first presence detection result indicates presence of hygiene consumable , address a subsequent sensor arranged upstream relative to the previously addressed sensor and in the depletion direction, obtain a subsequent presence detection result from the addressed sensor, repeat said addressing and obtaining as long as the subsequent presence detection result indicates presence of hygiene consumable .

6 . The sensor arrangement according to claim 5 , wherein the processing section is further configured, i f the subsequent presence detection result indicates no presence of hygiene consumable , store , as the start information, information indicating the sensor addressed before the addressed subsequent sensor .

7 . The sensor arrangement according to claim 5 , wherein the processing section is further configured to repeat said addressing and obtaining as long as the subsequent presence detection result indicates presence of hygiene consumable and as long as a first sensor at a beginning of the depletion direction is not reached .

8 . The sensor arrangement according to any one of claims 5 to

7 , wherein the processing section is further configured to determine that a refill of the reservoir has taken place i f the first presence detection result indicates presence of hygiene consumable .

9 . The sensor arrangement according to any one of claims 1 to

8 , wherein the processing section is further configured to store information indicating the filling state of the reservoir of the hygiene consumable on the basis of and/or in relation to the stored start information .

10 . The sensor arrangement according to claim 9 , wherein the processing section is further configured to compile a reporting message on the basis of the information indicating the filling state .

11 . The sensor arrangement according to claim 9 or 10 , wherein the processing section is further configured to repeat a ) through d) periodically and to decrease the time period in relation to the filling state .

12 . The sensor arrangement according to any one of claims 1 to

11 , wherein the sensors are arranged at a smaller distance to each other toward the end of the depletion direction as compared to the distance to each other toward the start of the depletion direction .

13 . The sensor arrangement according to any one of claims 1 to

12 , further comprising a housing, wherein an elongate housing bar accommodates the set of sensors .

14 . The sensor arrangement according to any one of claims 1 to 13 , wherein the sensor is any one of light barrier sensor, a reflection sensor, a proximity sensor, and a capacitive sensor .

15 . A piece of hygiene equipment for a hygiene consumable , preferably a dispenser for dispensing said hygiene consumable , comprising a sensor arrangement according to any one of claims 1 to 14 .

16 . A method for detecting a filling state of a reservoir of a hygiene consumable by employing a sensor arrangement comprising a set of sensors arranged along a depletion direction of the reservoir, each sensor being configured to detect presence of hygiene consumable in its respective proximity, the method comprising the steps of : a ) obtaining start information indicating an individual sensor to be used as a start sensor ; b ) addressing the sensor indicated by the start information and obtaining a first presence detection result from the addressed sensor ; c ) i f the first presence detection result indicates no presence of hygiene consumable , addressing a subsequent sensor arranged downstream relative to the previously addressed sensor and in the depletion direction, and obtaining a subsequent presence detection result from the addressed sensor ; d) i f the subsequent presence detection result indicates presence of hygiene consumable , storing information indicating the addressed subsequent sensor as the start information .