METHOD FOR AUTOMATICALLY EVALUATING THE DEGREE OF CLEANLINESS OF THE FILTERING SYSTEM IN A DISHWASHING MACHINE

Abstract

 The present disclosure relates to a method for automatically evaluating the degree of cleanliness of the filtering system in a dishwashing machine (1) comprising a washing zone (2) provided with a washing fluid collection zone (2"') in which a filter (F) is positioned, comprising steps of: acquiring (11) a first digital image (11A) representative of a first condition of the filter (F), digitally processing (12) the first digital image 11A so as to obtain a first processed image 11B, wherein the first processed image (11B) identifies a first surface value related to the surface area of the collection tank (F") of the filter (F) in a first condition in which the filter (F) is clean, acquiring (13) a second digital image (13A) representative of a second condition of the filter (F), digitally processing (14) the second digital image (13A) so as to obtain a second processed image (13B), wherein the second processed image (13B) identifies a second surface value related to the surface area of an accumulation of dirt present in the collection tank (F") in a second condition in which the filter (F) contains an accumulation of dirt, comparing (15) the second surface value with the first surface value to calculate an occlusion percentage value (OCL) of the filter (F) when passing between the first condition and the second condition, generating (16) a dirt presence signal (Sig) indicative of the presence of an accumulation of dirt in said filter (F), when the occlusion percentage value (OCL) of the filter (F) exceeds a predefined threshold value, generating (17) a sound and/or visual signal indicative of an obstructed filter condition, when the dirt presence signal (Sig) is generated.

Description

Field of application

[0001] The present description relates to a method for automatically evaluating the degree of cleanliness of the filtering system in a dishwashing machine, according to the preamble of claim 1.

[0002] The present description also relates to a dishwashing machine configured to implement the method for automatically evaluating the degree of cleanliness of the filtering system in a dishwashing machine, according to the preamble of claim 10.

[0003] The present description also relates to a system composed of a dishwashing machine and a portable device that can be gripped by a user and configured to implement the method for automatically evaluating the degree of cleanliness of the filtering system in a dishwashing machine, according to the preamble of claim 13.

Description of the prior art

[0004] Dishwashing machines are known in the state of the art that are provided with optical devices such as photo cameras, television cameras or video cameras arranged in a fixed or movable position with respect to the washing tank to check the weight of the dishes or the degree of cleanliness of the dishes.

[0005] For example, documents WO2016008699 and US 2012/0138092 illustrate the aforesaid dishwashing machines. Furthermore, document US 2013/032171 A1 describes a dishwashing machine comprising a washing zone provided with a washing fluid collection zone in which a filter is positioned, and a method for automatically evaluating the degree of cleanliness of the filtering system of the dishwashing machine.

[0006] The use of a dishwasher as identified above envisages the loading of dishes into a washing zone thereof by the user and the use of a washing detergent.

[0007] Such detergent is usually positioned inside a dispenser which is provided with an appropriate door that opens automatically once the user has closed the door of the dishwasher and has started the pre-chosen wash program.

[0008] Dishwashing machines of the known type are provided with a filter positioned at the bottom of the washing water collection tank, so as to be able to filter the water during the washing cycle, in order to collect and retain any deposits of dirt. In particular, the function of the filtering system placed in the lower part of the dishwashing machine is to guarantee that the water used in the washing circuit is filtered from debris and from dirt so as to guarantee better washing performance. A further function of the filtering system is to prevent residues of food and/or other objects being able to be introduced into the washing and draining circuits of the product.

Problem of the prior art

[0009] During the use of a dishwashing machine and, specifically, during the loading of the dishes and/or following the washing cycles, it can happen that deposits of dirt can accumulate in the filtering system positioned inside the dishwasher. The presence of a consistent accumulation of dirt in the filtering system leads to a drastic drop in the washing performance of the dishwashing machine and, in the event of complete occlusion of the filter, to the impossibility to be able to drain or suck back the washing water. Therefore, in the aforesaid condition in which the filters are partially or totally occluded by dirt, a maintenance intervention is necessary by the user who has to clean the filter removing the accumulation of dirt.

SUMMARY OF THE INVENTION

[0010] The object of the invention in question is to overcome the drawbacks of the prior art.

[0011] A further object of the invention is that of realising a method, a dishwashing machine and a system for evaluating the degree of cleanliness of the filtering system in a dishwashing machine so as to prevent the problems of the prior art described above.

[0012] Such objects are reached through a method, a dishwashing machine and a system for automatically evaluating the degree of cleanliness of the filtering system in a dishwashing machine according to the following claims 1, 10 and 13, respectively.

Advantages of the invention

[0013] Thanks to the embodiment of the present invention, it is possible to realize a method that allows the user to be informed of the need for maintenance of the filters. This allows the user to perform the correct maintenance of the product by preventing the decline of the washing performance due to the presence of dirty filters.

[0014] Thanks to an embodiment of the present invention, it is possible to realize a method and related dishwashing machine and a dishwashing machine system and device that is portable by hand by a user that allows:

• any increase in noise of the dishwashing machine to be prevented,
• the washing performance to be optimized, and
• the cleanliness of the plates both from dirt and detergent to be guaranteed.

BRIEF DESCRIPTION OF THE DRA WINGS

[0015] The characteristics and advantages of the present disclosure will become clear from the following detailed description of a possible practical embodiment, illustrated by way of non-limiting example in the set of drawings, wherein:

• Figure 1 shows a flow diagram of the method according to the present invention;
• Figure 2 shows a front perspective view of a dishwashing machine of the built-in type, without finishing panels, configured to perform the method of Figure 1;
• Figure 3 shows a rear perspective view of the dishwashing machine of Figure 2 without some of the components thereof and the dishes;
• Figure 4 shows in detail a component of the dishwashing machine of figure 2 and 3;
• Figure 5 shows a flow diagram of the system according to the present invention.

DETAILED DESCRIPTION

[0016] Even when not explicitly highlighted, the individual characteristics described with reference to the specific embodiments must be considered as accessories and/or exchangeable with other characteristics, described with reference to other embodiments.

[0017] With reference to the appended figures 2, 3 and 4, 1 indicates a dishwashing machine, e.g. of the type built-in to a kitchen unit, free from finishing panels for better understanding of the internal volumes.

[0018] Such dishwashing machine 1 comprises a washing zone 2 and a door 3 that is associable in closure with the washing zone 2.

[0019] The dishwashing machine 1 identifies a base 1A, usually dedicated to housing the necessary mechanisms/devices for the performance of the main operations of the machine 1.

[0020] The washing zone 2 defines the volume inside which the dishes S are arranged.

[0021] In particular, the washing zone 2 is defined by a plurality of walls such as the base wall 2A, the side walls 2B and 2C, the top 2D and the bottom wall 2E and identifies an upper portion 2' and a lower portion 2".

[0022] The term upper/lower must be interpreted in light of the correct installation and condition of use of the dishwashing machine 1. In such scenario, the term upper relates to the more distant part from the base 1A while the term lower relates to the more proximal part to the base 1A.

[0023] The door 3 can be activated by hand by the user and/or with an electrical servomechanism and has the aim of hermetically closing the washing zone 2 so as to prevent any losses of washing liquid during the performance of the cleaning program.

[0024] In the following description the term S means for example a plate, cutlery, a glass, a saucepan, etc..

[0025] The impellers 5A,5B are of the type known per se and therefore shall not be described. It is worth highlighting here that there may be one or, preferably, two impellers 5A,5B arranged in the washing zone 2. In particular, the lower impeller 5A is placed in the lower zone 2' in proximity to the base 1A and the upper impeller 5B in the upper zone 2", preferably in the lower part of the upper zone 2".

[0026] The lower zone 2' of the washing zone 2, when the dishwasher 1 is in use, identifies the collection zone of the washing fluid 2"'. In particular, such washing fluid collection zone 2'" is interposed between the lower impeller 5A and the base wall 2A. With reference to figure 4, the washing fluid collection zone 2"' is configured as a washing water collection tank, first cleaned as it is sucked from the water mains network at the start of the cleaning cycle, and subsequently contaminated by the dirt residues once the washing cycle has finished. It is however best to highlight that the dirt residues may also be present when the water is sucked from the mains network at the start of the cleaning cycle as such residues are due to the preceding washing cycle(s) to the one in progress.

[0027] The dishwashing machine 1 is also provided with a filter F, illustrated schematically in figure 4, arranged on the bottom wall of the washing fluid collection zone 2"'. The filter F comprises a filtering element F' adapted to filter the washing water, so as to retain the dirt residues and debris produced during the course of the washing cycle. The filter F also comprises a collection tank F" that extends surrounding the filtering element F' to collect the residues and accumulations of dirt that are retained by the filtering element F'. It is worth highlighting that the filter F must be regularly cleaned through manual intervention by a user in order to remove the accumulation of dirt and debris contained in the collection tank F".

[0028] In the lower zone 2' and/or in the upper zone 2" a respective dish holder basket 21 is arranged which has the function of housing the various dishes S, according to techniques known in the art and therefore not described.

[0029] The term dish holder basket 21 means any device and/or accessory dedicated to the positioning thereof and therefore suitable for supporting the dishes S.

[0030] Such basket and/or accessories must be compatible with the dimensions of the washing zone 2 of the dishwashing machine 1.

[0031] The dishwashing machine 1 comprises a dispenser 6 conformed so as to define a suitable volume for housing the products or detergents necessary for cleaning objects, in particular dishes S.

[0032] Such dispenser 6 may comprise one or more compartments each intended to receive a specific washing product.

[0033] According to one aspect, the dispenser 6 comprises a door 7 that is configured to pass between a closed position and a free access position to the internal volume of the dispenser 6.

[0034] For example, in the closed position of the door 7 products are prevented from being able to exit from their respective compartments while in the open position of the door 7, such washing products can exit, once the door 3 is in its closed position and a wash program P has been selected with which to wash the dishes S.

[0035] In other words, the passage of the door 7 between the closed position and the open position is controlled mechanically and/or electrically by the control unit 4 following the closure of the door 3 of the dishwashing machine 1.

[0036] According to one aspect, also with reference to Figures 2 and 3, the dispenser 6 is located on the door 3, in particular on the side facing towards the washing zone 2, at a predefined height. More in particular, the dispenser 6 is housed inside the thickness of the door 3.

[0037] The dishwashing machine 1 comprises a control unit 4, e.g. arranged in the thickness of the door 3 provided with a mother plate on which the usual electrical and electronic devices are housed which may include a CPU, a series of I/O ports for receiving and emitting data in a memory bank, the latter having a dedicated portion for permanently storing at least one cleaning program.

[0038] The cleaning program P is the result of one or a combination of more than one of the following parameters:

• duration of the washing step;
• pressure of the wash pump;
• temperature of the washing and drying steps;
• litres of water loaded.

[0039] The program P may also comprise other parameters that are not described here for description simplicity purposes.

[0040] The control unit 4 is a unit configured to control and monitor the operating functions of the dishwashing machine 1.

[0041] In one embodiment of the present invention, it is envisaged that in the memory of the control unit 4 a database is also permanently stored in which through appropriate parameters information is stored on the operating data collected by the sensors present inside the dishwashing machine. Various sensors will be described below intended to collect parameters within the dishwashing machine during the operation thereof, such as for example optical devices.

[0042] In order to allow the implementation of the selected cleaning program, the dishwashing machine 1 comprises a pump, e.g. arranged in the base 1A, which can be connected, according to techniques known to a person skilled in the art and therefore not described, with a mains water inlet.

[0043] Such pump is controlled by the control unit 4 and has the task of making water flow into the impellers 5A, 5B arranged inside the washing zone.

[0044] The dishwashing machine 1 comprises one or more optical devices 8 able to acquire digital images of the washing zone 2.

[0045] According to a preferred aspect of the invention, the optical devices 8 are arranged so that their optics are facing towards the washing fluid collection zone 2'" which, as already mentioned before, is interposed between the lower impeller 5A and the base wall 2A. In particular, the optical devices 8 are arranged so that their optics are facing towards the filter F, and in particular towards the collection tank F" and, optionally, also towards the filtering element F'.

[0046] In particular, each wall 2A, 2B, 2C, 2D and/or 2E of the washing zone 2 can each house, within their thickness, one or more of the aforesaid optical devices 8.

[0047] For that purpose a seat (not illustrated in the appended figures) is provided for each optical device 8.

[0048] The seat defines a suitable volume for housing the respective optical device and, preferably, to cover the optics of the optical device, a covering panel is provided which is transparent to light.

[0049] Such covering panel is, for example, made of glass or plastic or materials having similar technical properties.

[0050] The covering panel is preferably arranged so as to be substantially flush or slightly projecting from the surface of the wall 2A, 2B, 2C, 2D or 2E.

[0051] According to a preferred embodiment not illustrated in the appended figures, the optical devices 8 are housed inside respective seats obtained in the body of the dishwashing machine 1 at the washing fluid collection zone 2"'. Preferably, the washing fluid collection zone 2'" is configured like a collection tank for the washing liquid which has a bottom wall and a side wall (or various side walls) that define a container for collecting liquids.

[0052] Preferably, the seat in which one or more respective optical devices 8 are housed is obtained in the thickness of the side wall of the washing fluid collection zone 2"', so that the optical device 8 is able to transversally scan the washing fluid collection zone 2"', and in particular for acquiring images of the collection tank F" of the filter F. Coherently, the covering panel 8A is substantially arranged flush with the side wall of the washing fluid collection zone 2"'.

[0053] All the electrical and electronic elements necessary for the operation of the optical device 8 are arranged in each seat. Such arrangement is advantageous considering that it allows the optical device 8 to frame the washing fluid collection zone 2"', and in particular of the collection tank F", throughout the entire washing cycle.

[0054] Preferably, the optical device 8 has an optical field of view that allows the images of the washing fluid collection zone 2'" that fall within such predefined field of view to be acquired and, even more preferably, focused on the surface area of the collection tank F".

[0055] The purpose of the optical devices 8 used in the dishwashing machine 1 is that of acquiring two-dimensional images that are fixed and/or in sequence, at predetermined capture speeds, such as for example a single photogram, or a burst of images, or an uninterrupted flow of images of the washing fluid collection zone 2"', and in particular of the collection tank F" of the filter F.

[0056] According to a preferred form, the optical devices 8 acquire the images of the filter F seen transversally from the side wall of the washing fluid collection zone 2"', so as to view and clearly identify the surface area of the collection tank F". Alternatively or in combination with the previous embodiment, the optical devices 8 acquire the images of the filter F seen from the top 2D, so as to view and clearly identify the surface area of the collection tank F".

[0057] It is worth highlighting that the aforesaid optical devices 8 preferably acquire the images of the washing fluid collection zone 2"', and in particular of the collection tank F", throughout the whole washing cycle, at pre-established time intervals or with a predefined acquisition frequency. Preferably, the optical devices are configured to acquire the images of the collection tank F" at the end of each washing cycle.

[0058] Such optical devices 8 are in signal communication with the control unit 4 through its I/O ports in order to send the data acquired to the control unit 4.

[0059] Such optical devices 8, for example, are embodied in a photo camera and/or a video camera. Such devices are known in the sector and therefore will not be described in detail in the present description.

[0060] In the present description it is however worth highlighting that the photo camera and/or video camera, which can be used in the dishwashing machine 1 are preferably able to acquire images with lower acquisition times than a tenth of a second and adhere to the technical specifications according to which their operation is guaranteed also in the presence of water, i.e. the photo camera and/or video camera comply with the standard IP x(1-8).

[0061] Alternatively, or in combination with such technical specifications, it is envisaged that the seat, within which the optical devices 8 are arranged, is configured so as to be hermetic to water, e.g. using sealing techniques.

[0062] The dishwashing machine 1 comprises a user interface 9, i.e. the command and control interface through which the user can control and manage the operations and functions of the dishwashing machine itself.

[0063] For that purpose, the user interface 9 is in signal communication with the control unit 4 through its I/O ports in order to receive the data processed by the CPU of the control unit 4 itself.

[0064] In one embodiment, the user interface 9 is a screen 23 integrated into the dishwashing machine 1 so that it can be visible to a user during its normal use and/or with the addition of a buzzer (not shown in the figure).

[0065] According to one aspect, with reference to figures 2 and 3, the user interface 9 is integrated into the door 3 so that the screen faces the washing zone 2 externally.

[0066] It is worth highlighting that the screen 23 of the user interface 9 is configured to display luminous indications, text messages and/or single or continuous images. In particular, the images that can be displayed on the screen may be images of the washing zone 2 and of the related objects provided there acquired by the optical devices 8.

[0067] In particular, the screen may be of the touch type.

[0068] In another embodiment, the user interface 9 comprises one or more analog buttons and/or a combination of analog/digital controls and/or a combination of analog/digital controls and a screen, the latter for example of the touch type.

[0069] The buzzer of the user interface 9 has the aim of reporting any operating conditions or situations to the user through an acoustic signal.

[0070] In one embodiment, the dishwashing machine 1 comprises a radio transceiver device which is configured to create a signal communication with a wired and/or wireless network. For example, the wireless network may be a network based on an internet protocol through a WI-FI connection or a WPAN (Wireless Personal Area Network) based on Bluetooth protocol.

[0071] In this hypothesis, the user interface 9 also comprises a portable device (i.e. transportable or graspable by a hand of a user) 22 such as, for example, a smartphone, a tablet, a pc or similar instruments.

[0072] In other words, the user interface 9 comprises both the usual control interface of the dishwashing machine 1 and the screen of the transportable device 22.

[0073] In particular, the portable device 22 comprises its own radio transceiver device which is configured to establish a signal communication with the radio transceiver of the dishwashing machine 1.

[0074] According to one aspect, the portable device 22 as well as being able to communicate with the control unit 4 of the dishwashing machine 1 can also connect through the internet, e.g. through GSM infrastructure, with one or more remote servers 24 in order to perform the archiving, saving and/or processing operations of data on the images acquired by the optical devices 8.

[0075] In other words, the portable device 22 is suitable to connect both directly with the dishwashing machine 1 and with the internet through the GSM infrastructure. In such scenario, therefore, a system 25 is configured comprising the dishwashing machine 1, the portable device 22 in signal communication between them through GSM network, WI-FI connection and/or a WPAN network.

[0076] It is worth highlighting that the screen of the portable device 22 is configured to display luminous indications, text messages and/or images acquired from the optical devices 8.

[0077] In one embodiment of the present invention, if the user interface 9 also comprises the portable device 22 then it is envisaged that the database may be stored at least partially, preferably completely, in the memory of the portable device 22, in a mass memory of the server and/or, in distributed mode, between the memory of the dishwashing machine 1, of the portable device 22 and of the server 23.

[0078] According to one aspect, the control unit 4 is in signal communication with the user interface 9 (whether it is in the form of the actual screen only of the dishwashing machine 1 or that of the screen of the portable device 22) in order to be able to signal through the user interface 9 the blocked filter F condition and/or any modifications to be made to one or more of the cleaning parameters of the cleaning program P.

[0079] The term one or more of said cleaning parameters of the cleaning program P means in the present description any change to the parameters of the program P following the identification of the blocked filter F condition.

[0080] Now with reference to Figure 1, the method for automatically evaluating the degree of cleanliness of the filtering system of the dishwashing machine 1, comprises a step of acquiring 11 a first digital image 11A representative of a first condition of the filter F, in which the filter F is clean. Preferably, the acquisition step 11 is performed during the production and/or testing and/or initial configuration of the dishwashing machine 1, so as to obtain a first digital image 11A of the filter F in its maximum cleanliness condition.

[0081] Such acquisition step 11 is performed through the optical device(s) 8 provided inside the washing zone 2. For that purpose, the control unit 4 monitors the acquisition step by controlling the optical device(s) 8.

[0082] The method comprises a step of digitally processing 12 the first digital image 11A so as to obtain a first processed image 11B, in which the first processed image 11B identifies a first surface value related to the surface area of the collection tank F" of the filter F in the first condition in which the filter F is clean.

[0083] The method comprises a step of acquiring 13 a second digital image 13A representative of a second condition of the filter F, at the end of the washing cycle.

[0084] The method also comprises the step of digitally processing 14 the second digital image 13A so as to obtain a second processed image 13B, in which the second processed image 13B identifies a second surface value related to the surface area of a possible accumulation of dirt in the collection tank F" of the filter F in the second condition in which, for example, the filter F contains an accumulation of dirt.

[0085] For example, through the comparison with the first surface value identified by the first processed image 11B, it is possible to calculate the second surface value related to the surface area of any accumulation of dirt in the collection tank F" of the filter F in the second condition at the end of the washing cycle. In particular, the second surface value of the second processed image 13B can be calculated by subtracting the value of the free surface area of the collection tank F" from the first surface value, where the value of the free surface area represents the part of surface of the second processed image 13B that does not represent the accumulation of dirt in the collection tank F" of the filter F.

[0086] The method comprises a step of comparing 15 the second surface value with the first surface value for calculating an occlusion percentage value OCL of the filter F when passing between the first condition and the second condition.

[0087] The method also comprises the step of generating 16 a dirt presence signal Sig indicative of the presence of an accumulation of dirt in the filter F, when the occlusion percentage value OCL of the filter F exceeds a predefined threshold value.

[0088] The method further comprises the step of generating 17 a sound and/or visual signal indicative of a blocked filter condition, when the dirt presence signal Sig is generated.

[0089] Preferably, the method also comprises the step 18 of interrupting the cleaning cycle or modifying the parameters of the cleaning program P of the dishwashing machine 1 when the dirt presence signal Sig is generated.

[0090] It is worth highlighting that the steps of the method described herein below, the acquisition and processing steps, may be performed either directly by the CPU of the control unit 4 or, more preferably, by the CPU of the portable device of the user also through internet connection with the CPU of remote servers used for the analysis and processing of the data.

[0091] Preferably, the method also comprises the step of modifying 17 the cleaning parameters of the cleaning program P of the dishwashing machine 1 when the dirt presence signal Sig is generated.

[0092] According to a preferred solution, the step of comparing 15 the second surface value with the first surface value comprises the sub-step of calculating the ratio between the second surface value and the first surface value for calculating the occlusion percentage value OCL of the filter F when passing between the first condition and the second condition.

[0093] According to a preferred embodiment of the invention, the step of digitally processing 12 the first digital image 11A so as to obtain the first processed image 11B comprises the sub-step of splitting the surface area of the collection tank F" into a first predefined number of zones N. Each zone N has a predefined surface area value. In other words, the surface area of the collection tank F" is split into a grille composed of a first predefined number of zones N. The step of digitally processing 14 the second digital image 13A so as to obtain the second processed image 13B, comprises the sub-step of calculating a second number of zones N of the surface area of the collection tank F" occupied by the surface area of the accumulation of dirt in the filter F. The step of comparing 15 the second surface value with the first surface value comprises the sub-step of calculating the ratio between the second number of zones N and the first number of zones N to calculate the occlusion percentage value OCL of the filter F when passing between the first condition and the second condition. Preferably, the step of digitally processing 12 the first digital image 11A so as to obtain the first processed image 11B, comprises the sub-steps of:

• splitting the surface area of the filter F into a first predefined number of zones N, each zone N having a predefined surface area value, and
• calculating the first surface value by performing a sum of surface area values of the first number of zones N,

[0094] Preferably, the step of digitally processing 14 the second digital image 13A so as to obtain the second processed image 13B, comprises the sub-steps of:

• calculating a second number of zones N of the surface area of the collection tank F" occupied by the surface area of the accumulation of dirt in the filter F, and
• calculating the second surface value by performing a sum of surface area values of the second number of zones N.

[0095] According to a preferred embodiment of the invention, the first digital image 11A is representative of a first reference condition of the filter F before the use of the dishwashing machine 1. Preferably, the method comprises a step of starting a washing cycle of the dishwashing machine 1. In this circumstance, the second digital image 13A is representative of a second condition of the filter F after a predefined time interval following the step of starting the washing cycle and, more preferably, at the end of the washing cycle.

[0096] According to a preferred solution, the step of generating 16 a dirt presence signal Sig indicative of the presence of an accumulation of dirt in the filter F, comprises the sub-step of generating 16 the dirt presence signal Sig when the occlusion percentage value OCL of the filter F is greater than or equal to 10%. In other words, the dirt presence signal Sig occurs when at least 10% of the surface area of the collection tank F" of the filter F is obstructed by debris or accumulations of dirt.

[0097] According to a preferred embodiment, the method envisages iteratively repeating, during a washing cycle, the step of:

• acquiring 13 a second digital image 13A representative of the second condition of the filter F after a predefined time interval from the start time of a washing cycle of the dishwashing machine 1,
• digitally processing 14 the second digital image 13A so as to obtain the second processed image 13B,
• comparing 15 the second surface value with the first surface value for calculating the occlusion percentage value OCL of the filter F when passing between the first condition and the second condition,
• generating 16 a dirt presence signal Sig indicative of the presence of an accumulation of dirt in the filter F, when the occlusion percentage value OCL of the filter F exceeds a predefined threshold value.
• generating 17 the sound and/or visual signal indicative of a blocked filter condition, when the dirt presence signal Sig is generated.

[0098] According to a preferred solution, the step of acquiring 11 the first digital image 11A representative of the first condition of the filter F, comprises the sub-steps of storing the first digital image 11A in a database of the dishwashing machine 1.

[0099] Preferably, the step of generating 17 the sound and/or visual signal comprises the sub-step of signalling through the user interface 9 the sound and/or visual signal indicative of a blocked filter condition, when the dirt presence signal Sig is generated.

[0100] Still preferably, the method comprises the step of signalling through the user interface 9 the blocked filter condition when the dirt presence signal is generated and/or the interruption of the washing cycle and/or the modifications made to one or more of the cleaning program cleaning parameters P.

[0101] Advantageously, the method of the present invention allows the presence of dirt in the filter F of the dishwashing machine 1 to be detected.

[0102] Also advantageously, the method allows the washing cycle to be interrupted or one or more of the cleaning parameters of the cleaning program P to be modified as a function of the possible presence of dirt.

[0103] In particular, the cleaning parameters of the cleaning program that may be modified based on the filter F occlusion percentage detected and the time of the cycle in which it is detected are one or a combination of more than one of the following parameters:

• duration of the washing step;
• pressure of the wash pump;
• temperature of the washing and drying steps;
• litres of water loaded.

[0104] According to a preferred step, the method comprises a step of signalling through the user interface the presence of foam and/or the modifications made to one or more of the cleaning parameters of the cleaning program P so as to promptly inform the user of the variations made.

[0105] As has been seen, thanks to the method and the dishwashing machine 1 it is possible to signal through the user interface 9 the identification of a change in operating status of the machine itself in order to be able to restore the correct installation conditions of the object. This reduces the need to perform a dedicated wash for some dishes and/or to repeat the washing cycle with consequent water, detergent and energy consumptions.

[0106] It is necessary to specify that in conditions of absence of filter F occlusion, the second processed image 13B will not have any variation of the image compared to that of the first image processed 11B. Instead, in the presence of filter F occlusion, part of the surface area of the collection tank F" is occupied by an accumulation of dirt/debris and therefore the "blocked filter" condition will be identified.

[0107] According to a further preferred embodiment of the invention, it is possible to generate a "removal of filter occlusion" condition in the case in which, following the manual cleaning of the filter by a user all or almost all of the occlusion previously detected has been removed, obtaining a filter occlusion percentage value OCL lower than the threshold value. Furthermore, in the same way, it is possible to generate a "clean filter" signal when the occlusion percentage value OCL is equal to zero.

[0108] Obviously, a person skilled in the art, for the purpose of satisfying contingent and specific requirements, can make numerous modifications to the variants described above, all therefore contained within the scope of protection as defined in the following claims.

Claims

1. Method for automatically evaluating the degree of cleanliness of the filtering system in a dishwashing machine (1) comprising a washing zone (2) provided with a washing fluid collection zone (2"'), in which a filter (F) is positioned, said method being characterized in that it comprises the steps of:

- acquiring (11) a first digital image (11A) representative of a first condition of said filter (F),

- digitally processing (12) said first digital image (11A) so as to obtain a first processed image (11B), in which said first processed image (11B) identifies a first surface value related to the surface area of the collection tank (F") of said filter (F) in a first condition in which said filter (F) is clean,

- acquiring (13) a second digital image (13A) representative of a second condition of said filter (F),

- digitally processing (14) said second digital image (13A) so as to obtain a second processed image (13B), in which said second processed image (13B) identifies a second surface value related to the surface area of an accumulation of dirt in said collection tank (F") of said filter (F) in a second condition in which said filter (F) contains an accumulation of dirt,

- comparing (15) said second surface value with said first surface value for calculating an occlusion percentage value (OCL) of said filter (F) when passing between said first condition and said second condition,

- generating (16) a dirt presence signal (Sig) indicative of the presence of an accumulation of dirt in said filter (F), when said occlusion percentage value (OCL) of said filter F exceeds a predefined threshold value,

- generating (17) a sound and/or visual signal indicative of a blocked filter condition, when said dirt presence signal (Sig) is generated.

2. Method according to claim 1, wherein:

- said step of comparing (15) said second surface value with said first surface value comprises the sub-step of calculating the ratio between said second surface value and said first surface value for calculating said occlusion percentage value (OCL) of said filter (F) when passing between said first condition and said second condition.

3. Method according to claim 1, wherein:

- said step of digitally processing (12) said first digital image (11A) so as to obtain said first processed image (11B), comprises the sub-step of splitting said surface area of said collection tank (F") into a first predefined number of zones (N), each zone (N) having a predefined surface area value,

- said step of digitally processing (14) said second digital image (13A) so as to obtain said second processed image (13B), comprises the sub-step of calculating a second number of zones (N) of said surface area of said collection tank (F") occupied by said surface area of said accumulation of dirt in said filter (F),

- said step of comparing (15) said second surface value with said first surface value comprises the sub-step of calculating the ratio between said second number of zones (N) and said first number of zones (N) for calculating said occlusion percentage value (OCL) of said filter (F) when passing between said first condition and said second condition.

4. Method according to claim 1 or 2, wherein:

- said step of digitally processing (12) said first digital image (11A) so as to obtain said first processed image (11B), comprises the sub-steps of:

- splitting said surface area of said filter (F) into a first predefined number of zones (N), each zone (N) having a predefined surface area value,

- calculating said first surface value by performing a sum of surface area values of said first number of zones (N),

- said step of digitally processing (14) said second digital image (13A) so as to obtain said second processed image (13B), comprises the sub-steps of:

- calculating a second number of zones (N) of said surface area of said collection tank (F") occupied by said surface area of said accumulation of dirt in said filter (F),

- calculating said second surface value by performing a sum of surface area values of said second number of zones (N).

5. Method according to claim 1, wherein:

- said first digital image (11A) is representative of a first reference condition of said filter (F) before the use of said dishwashing machine (1),

- said method comprises a step of starting a washing cycle of said dishwashing machine (1),

- said second digital image (13A) is representative of a second condition of said filter (F) after a predefined time interval following said step of starting said washing cycle.

6. Method according to any one of the preceding claims, wherein:

- said step of generating (16) a dirt presence signal (Sig) indicative of the presence of an accumulation of dirt in said filter (F), comprises the sub-step of generating (16) said dirt presence signal (Sig) when said occlusion percentage value (OCL) of said filter (F) is greater than or equal to 10%,

7. Method according to any one of the preceding claims, wherein said method envisages iteratively repeating, during a washing cycle, the step of:

- acquiring (13) a second digital image (13A) representative of said second condition of said filter (F) after a predefined time interval from the start time of a washing cycle of said dishwashing machine (1),

- digitally processing (14) said second digital image (13A) so as to obtain said second processed image (13B),

- comparing (15) said second surface value with said first surface value for calculating said occlusion percentage value (OCL) of said filter (F) when passing between said first condition and said second condition,

- generating (16) a dirt presence signal (Sig) indicative of the presence of an accumulation of dirt in said filter (F), when said occlusion percentage value (OCL) of said filter F exceeds a predefined threshold value,

- generating (17) said sound and/or visual signal indicative of a blocked filter condition, when said dirt presence signal (Sig) is generated.

8. Method according to any one of the preceding claims, said step of acquiring (11) said first digital image (11A) representative of said first condition of said filter (F), comprising the sub-steps of storing said first digital image (11A) in a database of said dishwashing machine (1).

9. Method according to any one of the preceding claims, wherein said dishwasher (1) comprises a user interface (9), and said step of generating (17) said sound and/or visual signal comprises the sub-step of signalling through said user interface (9) said sound and/or visual signal indicative of a blocked filter condition, when said dirt presence signal (Sig) is generated.

10. Dishwashing machine (1) comprising a pump that can be connected to a mains water inlet for taking clean water from the network, one or more impellers (5A,5B) in fluid communication with such pump, a washing zone (2) provided with a washing fluid collection zone (2"') interposed between the lower impeller (5A) and the base wall (2A) of said washing zone (2), a filter (F) arranged on the bottom wall of the washing fluid collection zone (2"'), and a door (3) that can be associated in closure with said washing zone (2), a control unit (4) having a memory in one portion of which a cleaning program (P) is stored, a dispenser (6) configured to release a detergent into said washing fluid collection zone (2'"), and one or more resistive means for varying the temperature of the mains water, one or more optical devices (8) able to acquire digital images of said filter (F) and a user interface (9), said one or more optical devices (8) and said user interface (9) being in signal communication with said control unit (4), characterized in that it comprises a program resident in another portion of said memory structured to perform the method according to any one of the preceding claims from 1 to 9.

11. Dishwashing machine according to claim 10, wherein said user interface (9) is a screen integrated into said dishwashing machine, said screen (23) being configured to display said blocked filter signal through luminous type indications, text messages and/or images.

12. Dishwashing machine according to claim 10, wherein said dishwashing machine comprises a radio transceiver apparatus and said user interface (9) is a portable device having its own radio transceiver apparatus configured to establish a signal communication with said radio transceiver apparatus of said dishwashing machine (1) so as to receive data representative of said blocked filter signal through luminous type indications, messages and/or images.

13. System for automatically evaluating the degree of cleanliness of the filtering system in a dishwashing machine (1), comprising:

- a dishwashing machine comprising a pump that can be connected to a mains water inlet for taking clean water from the network, one or more impellers (5A,5B) in fluid communication with such pump, a washing zone (2) provided with a washing fluid collection zone (2"') interposed between the lower impeller (5A) and the base wall (2A) of said washing zone (2), a filter (F) arranged on the bottom wall of said washing fluid collection zone (2"'), and a door (3) that can be associated in closure with said washing zone (2), a control unit (4) having a memory in one portion of which a cleaning program (P) is stored, a dispenser (6) for dispensing a detergent and one or more resistive means for varying the temperature of the mains water, one or more optical devices (8) able to acquire digital images of said washing fluid collection zone (2"') and a user interface (9), said one or more optical devices (8) and user interface (9) being in signal communication with said control unit (4) like said pump and a radio transceiver apparatus;

- a portable device (22) that can be grasped by a hand of a user, having its own radio transceiver apparatus configured to establish a signal communication with said radio transceiver apparatus of said dishwashing machine, a screen configured to display luminous type indications, messages and/or images and a memory,

characterized in that it comprises a program resident in a portion of said portable device memory (22) that can be grasped by a user, said program being structured to perform the method according to any one of the preceding claims from 1 to 9 so as to display, on said interface (9) and/or on said screen of said mobile device graspable by a user, said blocked filter signal through luminous type indications, text messages and/or images.

Drawing