Cleaning system for a dishwashing appliance

Abstract

Disclosed herein is a screen assembly (200) for preventing soiling of an optical sensor (320) in a dishwasher (100) having a washing cavity (110) and at least one washware support (120) for receiving washware (121), comprising a sealed housing (210) configured to house the optical sensor (320), a transparent screen (220) arranged in the sealed housing (210), at least one nozzle (230) configured to deliver a fluid (400) on a surface of the transparent screen (220), a fluid supply (140) arranged to provide a continuous flow of fluid to the at least one nozzle (230) wherein a fluid film (400) is formed on the transparent screen (220), flowing along the surface of the transparent screen (220) and wherein the optical sensor (320) is arranged to capture an image of the washing cavity (110) through the transparent screen (220) and the fluid film (400).

Description

Technical Field

[0001] The invention generally relates to optical components in dishwashing appliances and, more specifically, to a cleaning system for an optical component in a dishwashing appliance.Background

[0002] A typical dishwasher includes a washing cavity, a hydraulic circuit for a washing liquid, a hydraulic circuit for a detergent, and a hydraulic circuit for a rinsing liquid. Moreover, most dishwashers are manually loaded and unloaded through an opening closed by a door. The dishware is placed on a rack which is insertable into the washing cavity. Further, the dishwasher may have some type of user interface for a user to choose between different cleaning programs. Depending on the dishware loaded into the washing cavity, some cleaning programs may be more suitable than others. The cleaning programs may for example differ in time duration, amount of detergent and temperature of the washing / rinsing liquid. There are shortcomings to this type of dishwashers, for example the finite number of cleaning programs for a user to choose between, or relying on the knowledge of the user to determine the best cleaning program suitable for the loaded dishware.

[0003] Therefore, some dishwashers nowadays additionally include some type of optical system. The optical system may for example include a camera, for capturing an image or record a video of the washing cavity. The captured image or video may be used to determine for example the type of dishware, the material of the dishware or the cleanliness of the dishware. In this way, the optical system may aid the user in determining the best cleaning program for the current load of dishware. However, since the optical system needs to be installed inside, or with its field of view covering the inside of the washing cavity, there are drawbacks with these type of solutions. Since the inside of a washing cavity is typically an environment characterized by high levels of moisture, water droplets, food residuals and chemical agents, the field of view for the optical system is easily impaired. An impaired image or video of the washing cavity may destroy the result and affect the cleaning process in a negative way. Therefore, the lens or screen through which the optical system captures the image or video must be clean before the image or video can be captured. If the optical system is configured to capture several images throughout the cleaning program, this quickly becomes a problem.

[0004] Some existing cleaning systems attempting to solve this problem includes a wiper for wiping the lens or screen prior to capturing an image. However, in the situation above where the image should be captured throughout the cleaning process, this solution is expensive and inefficient because it doesn't maintain the screen clean long enough before it is once again soiled.Summary

[0005] In light of the above, it is desired to provide alternate solutions for preventing soiling of optical systems, especially for optical systems in dishwashers. These and other objects are achieved by providing a screen assembly having the features in the independent claims. Preferred embodiments are defined in the dependent claims.

[0006] Hence, according to a first aspect of the present invention, there is provided a screen assembly for preventing soiling of an optical sensor in a dishwasher having a washing cavity and at least one washware support for receiving dishware, the screen assembly comprising a sealed housing configured to house the optical sensor, the sealed housing comprising at least one wall, a transparent screen arranged in the at least one wall of said sealed housing, at least one nozzle arranged at a top side of the transparent screen and configured to deliver a fluid on a surface of the transparent screen, a fluid supply arranged to provide a continuous flow of fluid to the at least one nozzle, wherein a fluid film is formed on the transparent screen, flowing along the surface of the transparent screen from the top side to a bottom side thereof, and wherein the optical sensor is arranged to capture an image of the washing cavity through the transparent screen and the fluid film.

[0007] The screen assembly therefore advantageously provides a continuous fluid film on the transparent screen of the sealed housing. The fluid film may prevent the formation of condensate or 'halos' on the transparent screen, as well as preventing debris or droplets from sticking to the transparent screen. Thereby, the screen assembly may ensure that the optical sensor installed inside the sealed housing may capture an image or a film of the washing cavity free from obstructions.

[0008] According to an exemplifying embodiment of the present disclosure, the image captured by the optical sensor contains information regarding a characteristic of the washware, wherein the characteristic is at least one of a material of the washware, a type of washware, and a presence of soil on the washware. The image or film captured of the washing cavity may be used as input into an intelligent system, for example a machine learning model, which may be configured to determine different characteristics of the washware loaded therein, and classify the washware into different categories. The characteristics and / or categories may be used to determine a washing program, with predetermined values such as temperature, duration and detergent dose, for example. This is advantageous in that the washing program may be adapted to the washware that is loaded into the washing cavity, without the interference of the user. In this way, the optimal treatment for the currently loaded washware may be ensured. Further, the risk of damaging the washware due to the temperature being too high, or similar, may be reduced. In order for these advantages to be available, it is important that the image or film captured is free from obstruction, otherwise the intended machine learning model(s) may not work as intended.

[0009] Therefore, according to a second aspect of the present invention, there is provided a dishwasher comprising a screen assembly according to the first aspect, the dishwasher comprising a washing cavity, a washware support configured to receive washware, a drain arranged in a bottom of the washing cavity and configured to drain a fluid from the washing cavity, and a fluid supply for washing fluid configured to provide the washing cavity with a washing fluid, a detergent configured to clean the washware loaded in the washware support, an optical sensor arranged in the screen assembly and configured to capture an image of the washing cavity, and a control unit connected to the optical sensor, wherein the control unit is configured to, based on information from the image captured by the optical sensor, control a washing cycle of the dishwasher to clean the washware in the washware support.

[0010] With the present dishwasher, the diswhare loaded in the washing cavity may advantageously be cleaned from soil according to the washing cycle determined by the control unit. As previously mentioned, the information from the image captured by the optical sensor may be fed as input into the control unit.

[0011] According to an exemplifying embodiment of the present disclosure, the control unit is configured to, based on the characteristic of the washware, choose a washing cycle from a list of available washing cycles. The control unit may further be connected to an intelligent system, and more specfically to a machine learning model, configured to analyze the captured image of the washing cavity. The image captured by the optical sensor may therefore be fed into the machine learning model, which analyses the image and transmits the output of the analysis to the control unit which uses the output of the machine learning model to determine a washing cycle for the currently loaded washware. The output of the machine learning model may include information regarding the characteristics of the washware. For example, the information may include a type of washware (plate, mug, glass, bowl, saucer, pan, etc), a material of the washware (glass, metal, ceramic, porcelain, etc), and further. The information from the machine learning model may further include information regarding a category of the washware. The machine learning model may thus further be configured to divide the loaded washware into different categories, for example utensils, tools, plates, glasses, etc. The output from the machine learning model to the control unit may therefore include a category, based on which the control unit may determine a washing cycle suitable for that caterogy. The dishwasher may therefore advantageoulsy provide a way to ensure that regardless of the washware loaded into the washing cavity, the washware is treated optimally given their characteristics. The 'optimal' washing cycle may look different for saucers and pans than for wine glasses, for example. With the optical sensor capturing an image of the washing cavity and the currently loaded washware, and the machine learning model analyzing the captured image, the washware may be optimally treated each washing cycle. Further, it is the screen assembly that ensures that the image captured by the optical sensor portrays the washware in a fair way, preventing the captured image from including obstructions, or soil, damaging the input to the machine learning model and possibly skewing the results fed to the control unit. By the screen assembly maintaining the field of view of the optical sensor free from obstructions, the screen assembly may assure that the machine learning model and the control unit works as intended. If the image captured by the optical sensor does not show a fair view of the washware, the dishwasher may not work as intended, and all the advantages with having a machine learning model may be moot.

[0012] By the term "optical sensor" is herein meant any type of sensor capable of identifying the interior of a washing cavity in a dishwasher. The optical sensor may for example be a camera, a film camera, or an IR sensor, for example.

[0013] By the term "dishwasher" is herein meant a dishwasher for domestic use or a dishwasher for use in a professional environment.

[0014] By the term "intelligent system" or "machine learning model" is herein meant any type of intelligent system or machine learning model capable of image analysis.

[0015] As mentioned, the dishwasher comprises a washing cavity and at least one washware support. The washware cavity may be sealed by a door, a hatch, or a curtain, for example. The door, hatch or curtain may be opened to access the washing cavity, and closed to seal the washing cavity and prevent access. An operator operating the dishwasher may therefore access the washing cavity when the door, hatch or curtain is opened, and perform their intended tasks in the washing cavity. When the operator has finished their task(s), the door, hatch or curtain may be closed again, sealing and restricting access to the washing cavity. The washing cavity may hold the at least one washware support. The at least one washware support may be a plurality of washware supports, distributed in the washing cavity at different levels, for example. The washware support(s) may be a rack configured to receive washware. The washware support(s) may be removably arranged inside the washing cavity. The washware support(s) may be removed from the washing cavity to be emptied from cleaned washware, or filled with soiled washware. The washware support(s) may for example be slidably arranged in the washing cavity, and arranged on guide rails arranged along one or more walls of the washing cavity.

[0016] Moreover, there may be a drain arranged inside the washing cavity, for draining the fluid(s) from the washing process. The drain may be arranged in a bottom of the washing cavity. Further, there may be a dishwasher arm arranged in the washing cavity. The dishwasher arm may comprise a plurality of nozzles for supplying a rinsing fluid and / or washing fluid to the washing cavity and the washware loaded in the washware support. The dishwasher arm may be rotatable to better distribute the rinsing fluid and / or washing fluid inside the washing cavity.

[0017] According to an exemplifying embodiment of the present disclosure, the washing fluid is water or a water solution.The water solution may for example be comprised by water and a detergent, for cleaning the washware. The rinsing fluid may be comprised by water and / or a polishing agent.

[0018] According to an exemplifying embodiment of the present disclosure, the dishwasher further comprises a light source for illuminating the washing cavity. The light source may for example be a lamp. The light source may be connected to the control unit, and be configured to be turned on in combination with the optical sensor capturing an image. This is advantageous since the light source may illuminate the washing cavity, and facilitating for the optical sensor to capture a sharp image of the washing cavity. When the door, hatch or curtain of the washing cavity is closed, the washing cavity may be dark, making it hard to capture a detailed image of the interior of the washing cavity. Therefore, the light source may be configured to illuminate the washing cavity when the optical sensor is scheduled to capture an image. In this way, the quality of the image may be increased, facilitating for the intelligent system to analyse the images.

[0019] According to an exemplifying embodiment of the present disclosure, the sealed housing of the screen assembly is arranged in the washing cavity. This is advantageous in that the optical sensor may be arranged close to the washware in the washing cavity which it is meant to capture an image of.

[0020] The screen assembly comprises a sealed housing configured to house the optical sensor. The sealed housing comprises at least one wall, and a transparent screen arranged in the at least one wall. The at least one wall may be arranged such that it faces the washing cavity. The at least one wall may be more than one wall, for example four side walls, a top wall and a bottom wall, such that it forms a box like structure. The box may be sealed such that no fluids may enter the box. In the example where the at least one wall comprises one wall, the wall may coincide with one of the walls in the washing cavity. The transparent screen being arranged in the at least one wall may be arranged in the wall facing the cavity. The transparent screen may be sealed around its edges such that no fluid or liquid may leak through the transparent screen. The transparent screen may have shape corresponding to the shape of the wall it is arranged in. Moreover, the transparent screen may be substantially rectangular, or oval.

[0021] According to an exemplifying embodiment of the present disclosure, a field of view of the optical sensor at least partially coincides with an area of the transparent screen. The transparent screen may have a shape allowing the optical sensor to capture as much as possible of the washing cavity, by for example not obstructing the optical sensor's field of view. The field of view of an optical sensor may be defined as the observable area seen through the photographic lens, i.e. the maximum area the optical sensor may capture. By arranging the transparent screen such that it at least partially coincides with the field of view of the optical sensor, the captured image may be kept free from obstructions. Since the transparent screen is maintained clean from soil and dirt by the fluid film, the field of view of the optical sensor may be kept free from obstructions due to it's at least partial coincideness with the transparent screen. The optical sensor is arranged in the sealed housing. The optical sensor may be oriented to be directed towards the washing cavity. The optical sensor may comprise a photographic lens for capturing the image of the washing cavity. Therefore, the photographic lens may be directed to point towards the washing cavity. Thereby, the optical sensor may capture an image of the washing cavity through the transparent screen of the screen assembly. According to an exemplifying embodiment of the present disclosure, the optical sensor is a camera. This is advantageous in that a camera may capture both still images and videos. Further, in the case where the captured image is intended to be used as input to an intelligent system, the use of a camera is advantageous, since the common file formats of images, for example ".jpeg", ".heif", ".tiff", ".raw", ".png", etc., are a widely known and used in a number of machine learning programs and / or models, which may facilitate the modeling of the intelligent system.

[0022] As most optical sensors are sensitive to liquids, for example due to their internal electrical components, the transparent screen may function as a protective screen, preventing liquid from coming into contact with the optical sensor. Further, the photographic lens of the optical sensor may be sensitive to impact. Photographic lenses typically include a sensitive glass, which may be easily scratched, quickly impairing the quality of the image captured through the photographic lens. The transparent screen may therefore advantageously function as a protective screen for preventing objects from coming into contact with the photographic lens of the optical sensor. For example, there may be soil splashing up towards the photographic lens during the washing cycle, or an incautious user accidentally coming into contact with the photographic lens while loading or unloading washware from the washware support. However, these events may be advantageously prevented by arranging the optical sensor in the sealed housing with a transparent screen.

[0023] Moreover, the sealed housing comprises at least one nozzle arranged at a top side of the transparent screen and configured to deliver a fluid on a surface of the transparent screen. The transparent screen may for example have a substantially rectangular shape, with a top side, a bottom side, a left and a right side. The top side of the transparent screen may be oriented to correspond to a top side of the washing cavity. The transparent screen may be arranged in a wall of the washing cavity, and more specifically in a vertically oriented wall in the washing cavity. For example, the washing cavity may have the shape of a box having four side walls, a top wall and a bottom wall, where one of the side vertical walls may comprise a door, a curtain or a hatch. Another one of the four vertical side walls may comprise the transparent screen. The at least one nozzle may therefore deliver a fluid to the top side of the transparent screen, such that the fluid may flow down the transparent screen from a top side to a bottom side thereof, due to its vertical orientation and the force of gravity.

[0024] According to an exemplifying embodiment of the present disclosure, the at least one nozzle is arranged on an outside of the sealed housing, inside the washing cavity. The at least one nozzle may be directed towards the transparent screen, such that the fluid coming from the at least one nozzle is sprayed directly onto the transparent screen. This enables the fluid to spread out on the transparent screen, forming a fluid film thereon. This is advantageous in that there is no distance between the fluid film and the transparent screen, where dirt or soil may get in. Moreover, dirt and / or soil sticking to the transparent screen may immediately be removed by the fluid film bringing it along on its way from the top side to the bottom side of the transparent screen. The at least one nozzle may be any type of nozzle suitable for delivering a fluid in a predetermined direction.

[0025] Further, the at least one nozzle may be arranged to deliver a fluid onto the transparent screen at a top side thereof, meaning that the area where the jet of fluid from the nozzle hits the transparent screen may not be a part of the field of view of the optical sensor. The jet of fluid from the nozzle may be turbulent, and cause turbulence on the area where it hits the transparent screen, which in its turn may obstruct the image captured by the optical sensor and result in a blurry image, which is undesired. However, allowing the fluid hitting the screen to flow down the screen by the force of gravity will allow the fluid to flow down the screen in an even flow, with minimal turbulence. Moreover, spraying the fluid directly onto the transparent screen may ensure that the fluid is evenly spread out on the screen which is advantageous since it provides a fluid film with an even thickness. In this way, the optical sensor may capture an image through the transparent screen and the fluid film, where the fluid film will not obstruct the captured image.

[0026] According to an exemplifying embodiment of the present disclosure, the at least one nozzle is a plurality of nozzles.The plurality of nozzles may be distributed along the length of the top side of the transparent screen. This is advantageous in that it may ensure that the fluid reaches the entirety of the transparent screen, such that the fluid film is formed over the entire area of the transparent screen. According to an exemplifying embodiment of the present disclosure, the plurality of nozzles are evenly distributed along a length L of the transparent screen. The flow rate of the fluid flowing along the transparent screen may be largest the closer to the nozzle. By arranging a plurality of nozzles evenly distributed along the length of the screen may ensure that soil or dirt sticking to the transparent screen may be removed by the fluid film regardless of where on the transparent screen the dirt sticks. Further, by arranging the plurality of nozzles evenly along the length of the transparent screen, the average value of the flow rate may be similar across the area of the transparent screen.

[0027] According to an exemplifying embodiment of the present disclosure, the fluid supply comprises a manifold with a plurality of channels, wherein each channel leads to a nozzle in the plurality of nozzles. Therefore, the plurality of nozzles may all be connected to the same fluid supply. Each nozzle may be connected to an individual "pipe" in the manifold. By providing each nozzle with an individual pipe in the manifold, and connecting the manifold to the fluid supply, the fluid pressure may be evenly distributed over the plurality of nozzles. This enables the fluid to be distributed to the plurality of nozzles with similar flow rate. If the fluid pressure over the plurality of nozzles is uneven, the fluid may be distributed over the transparent screen with different flow rates, possible leading to an uneven distribution of fluid over the transparent screen, which may cause turbulence on the transparent screen.

[0028] According to an exemplifying embodiment of the present disclosure, the fluid supply is configured to provide the washing fluid with a constant flow rate. The fluid supply may provide the at least one nozzle or plurality of nozzles continuously, such that a uniform fluid film is provided on the transparent screen. Moreover, the constant flow rate enables a smooth fluid film on the transparent screen, decreasing the risk of turbulence in the fluid film disturbing the captured image.

[0029] According to an exemplifying embodiment of the present disclosure, the fluid is water or a water solution. The fluid for the fluid film on the transparent screen may be the same fluid as the washing fluid. Therefore, according to an exemplifying embodiment of the present disclosure, the fluid supply for washing fluid is also the fluid supply of the screen assembly. This is advantageous in that the screen assembly may be installed without the need of adding additional fluid supplies in order to make it work. Moreover, according to an exemplifying embodiment of the present disclosure, the fluid flowing along the transparent screen of the screen assembly is collected by the drain of the dishwasher. Since the at lesat one nozzle or plurality of nozzles are installed in the washing cavity, the fluid flowing off the bottom side of the transparent screen may be collected in the bottom of the washing cavity and drained by the drain in the washing cavity.

[0030] According to an exemplifying embodiment of the present disclosure, the fluid is compressed air. In this example, the fluid supply may be an independent fluid supply, providing the at lesat one nozzle or the plurality of nozzles with compressed air. The compressed air may be sprayed from a top of the transparent screen towards the bottom side of the transparent screen, forming a curtain of air immediately in front of the transparent screen. The dirt or soil splashing up towards the transparent screen may then be caught by the air curtain and sprayed down towards the bottom of the washing cavity. Thereby, the transparent screen is kept free from dirt or soil, and the field of view of the optical sensor free from obstructions.Brief Description of the drawings

[0031] Exemplifying embodiments will now be described in more detail, with reference to the following appended drawings, in which: Figures 1a-b illustrate perspective views of a dishwasher according to exemplifying embodiments of the present disclosure; Figures 2a-c illustrate perspective views of a screen assembly according to exemplifying embodiments of the present disclosure; Figure 3 illustrates a side view of the screen assembly installed in a dishwasher according to an exemplifying embodiment of the present disclosure; Figures 4a-b illustrate a schematic view of a soiled and a cleaned transparent screen according to exemplifying embodiments of the present disclosure; Detailed description

[0032] As illustrated in the figures, the size of the elements and regions may be exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of the embodiments. Like reference numerals refer to like elements throughout.

[0033] Exemplifying embodiments will now be described more fully hereinafter with reference to the accompanying figures, in which currently preferred embodiments are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

[0034] With reference to Fig. 1a, a perspective view of a dishwasher 100 according to exemplifying embodiments of the present disclosure is shown. The dishwasher 100 may be suitable for washing, rinsing and drying and dishes, and different washing cycles may be available to choose from. The dishwasher 100 comprises a washing cavity 110 in which a washware support 120 is installed. The washware support 120 comprises a rack loaded with washware 121. The washware 121 may for example be dishes, glasses, bowls, plates, utensils, tools, pans, etc. The washware support 120 is slidably arranged in the washing cavity 110, such that an operator (not shown) may remove the washware support 120 from the washing cavity 110 to empty clean washware 121 from the washware support 120, or load the washware support 120 with soiled washware 121. The washing cavity 110 can be closed with a door 130. When the door 130 is closed, the washing cavity 110 is sealed, and an operator is prevented from accessing the washing cavity 110. When the door 130 is opened, the washing cavity 110 is accessible for an operator. The washing cavity 110 comprises a lighting source 113, for example a lamp. The lighting source 113 may be turned on when the door 130 is opened, or when the door 130 is closed and the washing cycle is running, to illuminate the washing cavity 110.

[0035] Moreover, the dishwasher 100 comprises a screen assembly 200. The screen assembly 200 is installed in a side wall 101 of the dishwasher 100. In the example embodiment shown in fig. 1a, the screen assembly 200 is arranged on an outside of the washing cavity 110. The screen assembly 200 comprises a sealed housing 210. The sealed housing 210 has a substantially rectangular shape, wherein a wall 211 of the sealed housing 210 is installed in the side wall 101 of the dishwasher 100. The wall 211 of the sealed housing 210 comprises a transparent screen 220. The side wall 101 of the dishwasher 100 may comprise a recessed portion where the wall 211 of the sealed housing 210 is installed. The sealed housing 210 houses an optical sensor 320, for example a camera. The sealed housing 210 provides protection for the optical sensor 320, preventing dirt, soil or liquids (not shown) from coming into contact with it. The optical sensor 320 is configured to capture images of the washing cavity 110. A photographic lens (not shown) of the optical sensor 320 may therefore be directed towards the washing cavity 110, such that the photographic lens may capture an image through the transparent screen 220. Because of its placement and direction inside the sealed housing 210, the optical sensor 320 has a field of view 321 covering the washing cavity 110. The field of view 321 of the optical sensor 320 therefore at least partially coincides with the area of the transparent screen 220, such that the transparent screen 220 does not obstruct optical sensor's 320 field of view 321. The transparent screen 220 may for example be made from a transparent glass or a transparent plastic. The optical sensor 320 may capture one or a plurality of images of the washing cavity 110 before, during, or after the washing cycle has been completed. The captured images (not shown) may be continuously fed to an intelligent system (not shown) via a control unit (not shown) to be analysed. The outcome of the analysis may comprise a decision regarding which washing cycle to run on the washware 121 currently loaded in the washware support 120. Different washware 121 may have different characteristics, for example depending on material, size, shape, etc. It may therefore be advantageous to choose a washing cycle based on the characteristics of the washware 121. The intelligent system may help making this decision with the input from the optical sensor 320. The lighting source 113 may be turned on inside the washing cavity 110 when the optical sensor 320 captures images, to ensure that the washware 121 is visible.

[0036] Turning now to fig. 1b, a dishwasher 100 is shown without the washware support 120. The washing cavity 110 comprises a drain 111, arranged in a bottom side 102 thereof. The drain 111 is confiugred to drain liquids from the washing cavity 110, which may be collected on the bottom side 102 of the washing cavity. For example, a washing fluid (not shown) which is supplied to the washing cavity 110 for cleaning the washware 121, may flow down to the bottom side 102 and to the drain 111. The dishwasher 100 is connected to a fluid supply 140, providing the washing cavity 110 with fluids, for example washing fluid, rinsing fluid, and a fluid (not shown) to the screen assembly 200. The fluid supply 140 may for example be a main water supply line. Moreover, there is a dishwasher arm 112 arranged in the bottom side 102 of the washing cavity 110. The dishwasher arm 112 is connected to the fluid supply 140 and may comprise one or more nozzles (not shown) for spraying water into the washing cavity 110. The dishwasher arm 112 may be rotatable, in order for the washing fluid and / or rinsing fluid to reach the entirety of the washing cavity 110.

[0037] In the exemplifying embodiment illustrated in fig. 1b, the screen assembly 200 is arranged inside the washing cavity 110. The screen assembly 200 comprises a sealed housing 210, why the optical sensor 320 housed inside the sealed housing 210 is protected from the washing fluid, rinsing fluid, and fluid supplied to the transparent screen 220. The screen assembly 200 may be arranged anywhere inside the washing cavity 110 where the optical sensor's 320 field of view 321 covers the at least one washware support 120 arranged therein.

[0038] Figure 2a illustrates a perspective view of a screen assembly 200 according to exemplifying embodiments of the present disclosure. The screen assembly 200 comprises a sealed housing 210, wherein one of the walls 211 is formed by the transparent screen 220. Inside the sealed housing 210 there is an optical sensor 320 arranged. The optical sensor 320 is directed with it's photographic lens towards the transparent screen 220, such that the field of view 321 of the optical sensor 320 at least partially coincides with the transparent screen 220. The optical sensor 320 may therefore capture images through the transparent screen 220, such that the transparent screen 220 functions as a protective screen without obstructing or impairing the quality of the captured image. The screen assembly 200 further comprises at least one nozzle 230 arranged at a top side 221 of the transparent screen 220. In the exemplifying embodiment shown in fig. 2a, the at least one nozzle 230 is a plurality of nozzles 230. The plurality of nozzles 230 are distributed along the lenght L of the transparent screen 220. The nozzles 230 may be evenly distributed along the length L, or distributed with different distances between them. The nozzles 230 are configured to deliver a fluid 400 on a surface of the transparent screen 220. The nozzles 230 are connected to a pipe 141, which is connected to a fluid supply 140. The fluid supply 140 providing the screen assembly 200 with fluid may be the same fluid supply 140 for supplying the washing cavity 110 with fluid. The nozzles 230 are oriented in a way such that the fluid 400 is delivered onto the surface of the transparent screen 220. The fluid 400 flows downwards from the top side 221 of the transparent screen 220 towards the bottom side 222 of the transparent screen 220. The fluid 400 flows along the surface of the transparent screen 220 due to the force of gravity, and the transparent screen 220 is vertically arranged. The fluid 400 is continuously delivered on to the transparent screen 220, forming a fluid film 400 thereon. The fluid film 400 is therefore maintained on the transparent screen 220 throughout the duration of the washing cycle, or a predetermined period when the optical sensor 320 is programmed to capture images. The fluid film 400 prevents dirt, soil or debris from sticking to the transparent screen 220, obstructing the image captured by the optical sensor 320. The fluid 400 delivered from the fluid supply 140 to the nozzles 230 may be water, or a water solution, for example. The fluid 400 flowing down the transparent screen 220 may bring debris, soil or dirt along with it on its way from the top side 221 to the bottom side 222, ensuring that the transparent screen 220 remains transparent for the optical sensor 320 to capture an image through.

[0039] Figure 2b illustrates a perspective view of a screen assembly 200 according to an exemplifying embodiment of the present disclosure. The nozzles 230 are connected to a manifold 160 which is connected to the fluid supply 140. The fluid supply 140 delivers fluid to the manifold 160, which is divided into a plurality of individual channels 160a, 160b, 160c, 160d, 160e, 160f, which each are connected to a nozzle 230. In this example, the fluid 400 delivered from the fluid supply 140 may maintain the same pressure over each individual channel 160a-f, such that the flow rate through each one of the nozzles 230 is substantially equal. The individual channels 160a-f may be evenly distributed along the length L of the transparent screen 220.

[0040] Turning to figure 2c, an exemplifying embodiment of a screen assembly 200 is shown, wherein the fluid delivered to the nozzles 230 is compressed air 410. The compressed air 41 is delivered to the nozzles 230 from a fluid supply for compressed air 420. The fluid supply for compressed air 420 may be a compressed air system, connected to the screen assembly 200. The nozzles 230 are directed such that the compressed air 410 is sprayed in front of the transparent screen 220, from a top side 221 towards a bottom side 222 thereof. The compressed air 410 forms a fluid film, or an air curtain 410 in front of the transparent screen 220. The compressed air 410 is continuously supplied through the nozzles 230 such that the air curtain 410 is maintained throughout the duration of the washing cycle, or a predetermined period when the optical sensor 320 is programmed to capture images. The air curtain 410 may prevent debris, soil or other dirt from reaching the transparent screen 220. Instead, the dirt, soil or debris may be caught by the air curtain 410 being sprayed downwards, and therefore the dirt, debris or soil may follow the air curtain 410 downwards to the bottom 102 of the washing cavity 110.

[0041] With reference to fig. 3, a side view of the of the screen assembly 200 installed in a dishwasher 100 according to an exemplifying embodiment of the present disclosure is shown. The sealed housing 210 is seen housing an optical sensor 320, the optical sensor 320 directed with the photographic lens facing the transparent screen 220. On the other side of the transparent screen 220, outside of the sealed housing 210, a washware support 120 is placed, loaded with washware 121. The washware support 120 is placed inside the washing cavity (not shown in the present figure). The screen assembly 200 is connected to the fluid supply 140, and a pipe 141 leading to a nozzle 230. The nozzle 230 is arranged in front of the transparent screen 220 outside of the sealed housing 210. The nozzle 230 sprays a fluid 400 towards the transparent screen 220. The jet of fluid 400 coming from the nozzle 230 hits the transparent screen 220 and flows down on the transparent screen 220, from a top side 221 to a bottom side 222 thereof, forming a fluid film 400. The optical sensor 320 may therefore capture an image of the washware support 120 and the washware 121, throught the transparent screen 220 and the fluid film 400.

[0042] With reference to figs. 4a and 4b, a schematic view of a soiled (fig. 4a) and a cleaned (fig. 4b) transparent screen 220 according to exemplifying embodiments of the present disclosure are shown. In figure 4a, a front view of a transparent screen 220 is shown, where no fluid film is present. The optical sensor 320 may be seen through the transparent screen 220, which is arranged in the foreground of the present figure. Dirt, soil and debris 600 is stuck on the transparent screen 220, obstructing the field of view 321 of the optical sensor 320. The image captured by the optical sensor 320 may therefore be unusable by the intelligent system (not shown), or contribute to a faulty or misleading result. The control unit (not shown) may be configured to sort out images with poor quality. However, if too many images are sorted out, there may not be enough image data for the intelligent system to be able to analyse and suggest a washing cycle on, resulting in poor use of the intelligent system and non-reliable results. A non-reliable result may for example be that the intelligent system suggests a washing cycle to the control unit that leads to non-satisfying washing results, for example dirty washware or damaged washware. Moreover, an image containing obstructions from dirt on the transparent screen 220 may lead to that the control unit comprising the intelligent system makes an erroneous analysis, mistaking the obstructions for washware 121.

[0043] Turning to figure 4b, a front view of a transparent screen 220 with a fluid film 400 present is shown. The optical sensor 320 may be seen through the transparent screen 220, which is arranged in the foreground of the present figure. The fluid film 400 is visible, flowing downwards from a top side 221 towards a bottom side 222 of the transparent screen 220. The dirt, soil and debris 600 that was stuck on the transparent screen 220 in the previous figure, fig. 4a, has instead of getting stuck on the transparent screen 220, followed the fluid film 400 downwards to the bottom side 222. It is clearly seen that the field of view 321 of the optical sensor 320 is free from obstructions caused by debris, soil and dirt 600. The image captured by the optical sensor 320 may therefore be provided to the intelligent system through the control unit, which will analyse the image and provide a reliable analysis, and a trustworthy result.

[0044] Although features and elements are described above in particular combinations, each feature or element can be used alone without the other features and elements or in various combinations with or without other features and elements.

[0045] Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the figures, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage.

Examples

Embodiment Construction

[0032]As illustrated in the figures, the size of the elements and regions may be exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of the embodiments. Like reference numerals refer to like elements throughout.

[0033]Exemplifying embodiments will now be described more fully hereinafter with reference to the accompanying figures, in which currently preferred embodiments are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

[0034]With reference to Fig. 1a, a perspective view of a dishwasher 100 according to exemplifying embodiments of the present disclosure is shown. The dishwasher 100 may be suitable for washing, rinsing and drying and dishes, and different washing cycles may be available to choose from. ...

Technical Field

[0001] The invention generally relates to optical components in dishwashing appliances and, more specifically, to a cleaning system for an optical component in a dishwashing appliance.Background

[0002] A typical dishwasher includes a washing cavity, a hydraulic circuit for a washing liquid, a hydraulic circuit for a detergent, and a hydraulic circuit for a rinsing liquid. Moreover, most dishwashers are manually loaded and unloaded through an opening closed by a door. The dishware is placed on a rack which is insertable into the washing cavity. Further, the dishwasher may have some type of user interface for a user to choose between different cleaning programs. Depending on the dishware loaded into the washing cavity, some cleaning programs may be more suitable than others. The cleaning programs may for example differ in time duration, amount of detergent and temperature of the washing / rinsing liquid. There are shortcomings to this type of dishwashers, for example the finite number of cleaning programs for a user to choose between, or relying on the knowledge of the user to determine the best cleaning program suitable for the loaded dishware.

[0003] Therefore, some dishwashers nowadays additionally include some type of optical system. The optical system may for example include a camera, for capturing an image or record a video of the washing cavity. The captured image or video may be used to determine for example the type of dishware, the material of the dishware or the cleanliness of the dishware. In this way, the optical system may aid the user in determining the best cleaning program for the current load of dishware. However, since the optical system needs to be installed inside, or with its field of view covering the inside of the washing cavity, there are drawbacks with these type of solutions. Since the inside of a washing cavity is typically an environment characterized by high levels of moisture, water droplets, food residuals and chemical agents, the field of view for the optical system is easily impaired. An impaired image or video of the washing cavity may destroy the result and affect the cleaning process in a negative way. Therefore, the lens or screen through which the optical system captures the image or video must be clean before the image or video can be captured. If the optical system is configured to capture several images throughout the cleaning program, this quickly becomes a problem.

[0004] Some existing cleaning systems attempting to solve this problem includes a wiper for wiping the lens or screen prior to capturing an image. However, in the situation above where the image should be captured throughout the cleaning process, this solution is expensive and inefficient because it doesn't maintain the screen clean long enough before it is once again soiled.Summary

[0005] In light of the above, it is desired to provide alternate solutions for preventing soiling of optical systems, especially for optical systems in dishwashers. These and other objects are achieved by providing a screen assembly having the features in the independent claims. Preferred embodiments are defined in the dependent claims.

[0006] Hence, according to a first aspect of the present invention, there is provided a screen assembly for preventing soiling of an optical sensor in a dishwasher having a washing cavity and at least one washware support for receiving dishware, the screen assembly comprising a sealed housing configured to house the optical sensor, the sealed housing comprising at least one wall, a transparent screen arranged in the at least one wall of said sealed housing, at least one nozzle arranged at a top side of the transparent screen and configured to deliver a fluid on a surface of the transparent screen, a fluid supply arranged to provide a continuous flow of fluid to the at least one nozzle, wherein a fluid film is formed on the transparent screen, flowing along the surface of the transparent screen from the top side to a bottom side thereof, and wherein the optical sensor is arranged to capture an image of the washing cavity through the transparent screen and the fluid film.

[0007] The screen assembly therefore advantageously provides a continuous fluid film on the transparent screen of the sealed housing. The fluid film may prevent the formation of condensate or 'halos' on the transparent screen, as well as preventing debris or droplets from sticking to the transparent screen. Thereby, the screen assembly may ensure that the optical sensor installed inside the sealed housing may capture an image or a film of the washing cavity free from obstructions.

[0008] According to an exemplifying embodiment of the present disclosure, the image captured by the optical sensor contains information regarding a characteristic of the washware, wherein the characteristic is at least one of a material of the washware, a type of washware, and a presence of soil on the washware. The image or film captured of the washing cavity may be used as input into an intelligent system, for example a machine learning model, which may be configured to determine different characteristics of the washware loaded therein, and classify the washware into different categories. The characteristics and / or categories may be used to determine a washing program, with predetermined values such as temperature, duration and detergent dose, for example. This is advantageous in that the washing program may be adapted to the washware that is loaded into the washing cavity, without the interference of the user. In this way, the optimal treatment for the currently loaded washware may be ensured. Further, the risk of damaging the washware due to the temperature being too high, or similar, may be reduced. In order for these advantages to be available, it is important that the image or film captured is free from obstruction, otherwise the intended machine learning model(s) may not work as intended.

[0009] Therefore, according to a second aspect of the present invention, there is provided a dishwasher comprising a screen assembly according to the first aspect, the dishwasher comprising a washing cavity, a washware support configured to receive washware, a drain arranged in a bottom of the washing cavity and configured to drain a fluid from the washing cavity, and a fluid supply for washing fluid configured to provide the washing cavity with a washing fluid, a detergent configured to clean the washware loaded in the washware support, an optical sensor arranged in the screen assembly and configured to capture an image of the washing cavity, and a control unit connected to the optical sensor, wherein the control unit is configured to, based on information from the image captured by the optical sensor, control a washing cycle of the dishwasher to clean the washware in the washware support.

[0010] With the present dishwasher, the diswhare loaded in the washing cavity may advantageously be cleaned from soil according to the washing cycle determined by the control unit. As previously mentioned, the information from the image captured by the optical sensor may be fed as input into the control unit.

[0011] According to an exemplifying embodiment of the present disclosure, the control unit is configured to, based on the characteristic of the washware, choose a washing cycle from a list of available washing cycles. The control unit may further be connected to an intelligent system, and more specfically to a machine learning model, configured to analyze the captured image of the washing cavity. The image captured by the optical sensor may therefore be fed into the machine learning model, which analyses the image and transmits the output of the analysis to the control unit which uses the output of the machine learning model to determine a washing cycle for the currently loaded washware. The output of the machine learning model may include information regarding the characteristics of the washware. For example, the information may include a type of washware (plate, mug, glass, bowl, saucer, pan, etc), a material of the washware (glass, metal, ceramic, porcelain, etc), and further. The information from the machine learning model may further include information regarding a category of the washware. The machine learning model may thus further be configured to divide the loaded washware into different categories, for example utensils, tools, plates, glasses, etc. The output from the machine learning model to the control unit may therefore include a category, based on which the control unit may determine a washing cycle suitable for that caterogy. The dishwasher may therefore advantageoulsy provide a way to ensure that regardless of the washware loaded into the washing cavity, the washware is treated optimally given their characteristics. The 'optimal' washing cycle may look different for saucers and pans than for wine glasses, for example. With the optical sensor capturing an image of the washing cavity and the currently loaded washware, and the machine learning model analyzing the captured image, the washware may be optimally treated each washing cycle. Further, it is the screen assembly that ensures that the image captured by the optical sensor portrays the washware in a fair way, preventing the captured image from including obstructions, or soil, damaging the input to the machine learning model and possibly skewing the results fed to the control unit. By the screen assembly maintaining the field of view of the optical sensor free from obstructions, the screen assembly may assure that the machine learning model and the control unit works as intended. If the image captured by the optical sensor does not show a fair view of the washware, the dishwasher may not work as intended, and all the advantages with having a machine learning model may be moot.

[0012] By the term "optical sensor" is herein meant any type of sensor capable of identifying the interior of a washing cavity in a dishwasher. The optical sensor may for example be a camera, a film camera, or an IR sensor, for example.

[0013] By the term "dishwasher" is herein meant a dishwasher for domestic use or a dishwasher for use in a professional environment.

[0014] By the term "intelligent system" or "machine learning model" is herein meant any type of intelligent system or machine learning model capable of image analysis.

[0015] As mentioned, the dishwasher comprises a washing cavity and at least one washware support. The washware cavity may be sealed by a door, a hatch, or a curtain, for example. The door, hatch or curtain may be opened to access the washing cavity, and closed to seal the washing cavity and prevent access. An operator operating the dishwasher may therefore access the washing cavity when the door, hatch or curtain is opened, and perform their intended tasks in the washing cavity. When the operator has finished their task(s), the door, hatch or curtain may be closed again, sealing and restricting access to the washing cavity. The washing cavity may hold the at least one washware support. The at least one washware support may be a plurality of washware supports, distributed in the washing cavity at different levels, for example. The washware support(s) may be a rack configured to receive washware. The washware support(s) may be removably arranged inside the washing cavity. The washware support(s) may be removed from the washing cavity to be emptied from cleaned washware, or filled with soiled washware. The washware support(s) may for example be slidably arranged in the washing cavity, and arranged on guide rails arranged along one or more walls of the washing cavity.

[0016] Moreover, there may be a drain arranged inside the washing cavity, for draining the fluid(s) from the washing process. The drain may be arranged in a bottom of the washing cavity. Further, there may be a dishwasher arm arranged in the washing cavity. The dishwasher arm may comprise a plurality of nozzles for supplying a rinsing fluid and / or washing fluid to the washing cavity and the washware loaded in the washware support. The dishwasher arm may be rotatable to better distribute the rinsing fluid and / or washing fluid inside the washing cavity.

[0017] According to an exemplifying embodiment of the present disclosure, the washing fluid is water or a water solution.The water solution may for example be comprised by water and a detergent, for cleaning the washware. The rinsing fluid may be comprised by water and / or a polishing agent.

[0018] According to an exemplifying embodiment of the present disclosure, the dishwasher further comprises a light source for illuminating the washing cavity. The light source may for example be a lamp. The light source may be connected to the control unit, and be configured to be turned on in combination with the optical sensor capturing an image. This is advantageous since the light source may illuminate the washing cavity, and facilitating for the optical sensor to capture a sharp image of the washing cavity. When the door, hatch or curtain of the washing cavity is closed, the washing cavity may be dark, making it hard to capture a detailed image of the interior of the washing cavity. Therefore, the light source may be configured to illuminate the washing cavity when the optical sensor is scheduled to capture an image. In this way, the quality of the image may be increased, facilitating for the intelligent system to analyse the images.

[0019] According to an exemplifying embodiment of the present disclosure, the sealed housing of the screen assembly is arranged in the washing cavity. This is advantageous in that the optical sensor may be arranged close to the washware in the washing cavity which it is meant to capture an image of.

[0020] The screen assembly comprises a sealed housing configured to house the optical sensor. The sealed housing comprises at least one wall, and a transparent screen arranged in the at least one wall. The at least one wall may be arranged such that it faces the washing cavity. The at least one wall may be more than one wall, for example four side walls, a top wall and a bottom wall, such that it forms a box like structure. The box may be sealed such that no fluids may enter the box. In the example where the at least one wall comprises one wall, the wall may coincide with one of the walls in the washing cavity. The transparent screen being arranged in the at least one wall may be arranged in the wall facing the cavity. The transparent screen may be sealed around its edges such that no fluid or liquid may leak through the transparent screen. The transparent screen may have shape corresponding to the shape of the wall it is arranged in. Moreover, the transparent screen may be substantially rectangular, or oval.

[0021] According to an exemplifying embodiment of the present disclosure, a field of view of the optical sensor at least partially coincides with an area of the transparent screen. The transparent screen may have a shape allowing the optical sensor to capture as much as possible of the washing cavity, by for example not obstructing the optical sensor's field of view. The field of view of an optical sensor may be defined as the observable area seen through the photographic lens, i.e. the maximum area the optical sensor may capture. By arranging the transparent screen such that it at least partially coincides with the field of view of the optical sensor, the captured image may be kept free from obstructions. Since the transparent screen is maintained clean from soil and dirt by the fluid film, the field of view of the optical sensor may be kept free from obstructions due to it's at least partial coincideness with the transparent screen. The optical sensor is arranged in the sealed housing. The optical sensor may be oriented to be directed towards the washing cavity. The optical sensor may comprise a photographic lens for capturing the image of the washing cavity. Therefore, the photographic lens may be directed to point towards the washing cavity. Thereby, the optical sensor may capture an image of the washing cavity through the transparent screen of the screen assembly. According to an exemplifying embodiment of the present disclosure, the optical sensor is a camera. This is advantageous in that a camera may capture both still images and videos. Further, in the case where the captured image is intended to be used as input to an intelligent system, the use of a camera is advantageous, since the common file formats of images, for example ".jpeg", ".heif", ".tiff", ".raw", ".png", etc., are a widely known and used in a number of machine learning programs and / or models, which may facilitate the modeling of the intelligent system.

[0022] As most optical sensors are sensitive to liquids, for example due to their internal electrical components, the transparent screen may function as a protective screen, preventing liquid from coming into contact with the optical sensor. Further, the photographic lens of the optical sensor may be sensitive to impact. Photographic lenses typically include a sensitive glass, which may be easily scratched, quickly impairing the quality of the image captured through the photographic lens. The transparent screen may therefore advantageously function as a protective screen for preventing objects from coming into contact with the photographic lens of the optical sensor. For example, there may be soil splashing up towards the photographic lens during the washing cycle, or an incautious user accidentally coming into contact with the photographic lens while loading or unloading washware from the washware support. However, these events may be advantageously prevented by arranging the optical sensor in the sealed housing with a transparent screen.

[0023] Moreover, the sealed housing comprises at least one nozzle arranged at a top side of the transparent screen and configured to deliver a fluid on a surface of the transparent screen. The transparent screen may for example have a substantially rectangular shape, with a top side, a bottom side, a left and a right side. The top side of the transparent screen may be oriented to correspond to a top side of the washing cavity. The transparent screen may be arranged in a wall of the washing cavity, and more specifically in a vertically oriented wall in the washing cavity. For example, the washing cavity may have the shape of a box having four side walls, a top wall and a bottom wall, where one of the side vertical walls may comprise a door, a curtain or a hatch. Another one of the four vertical side walls may comprise the transparent screen. The at least one nozzle may therefore deliver a fluid to the top side of the transparent screen, such that the fluid may flow down the transparent screen from a top side to a bottom side thereof, due to its vertical orientation and the force of gravity.

[0024] According to an exemplifying embodiment of the present disclosure, the at least one nozzle is arranged on an outside of the sealed housing, inside the washing cavity. The at least one nozzle may be directed towards the transparent screen, such that the fluid coming from the at least one nozzle is sprayed directly onto the transparent screen. This enables the fluid to spread out on the transparent screen, forming a fluid film thereon. This is advantageous in that there is no distance between the fluid film and the transparent screen, where dirt or soil may get in. Moreover, dirt and / or soil sticking to the transparent screen may immediately be removed by the fluid film bringing it along on its way from the top side to the bottom side of the transparent screen. The at least one nozzle may be any type of nozzle suitable for delivering a fluid in a predetermined direction.

[0025] Further, the at least one nozzle may be arranged to deliver a fluid onto the transparent screen at a top side thereof, meaning that the area where the jet of fluid from the nozzle hits the transparent screen may not be a part of the field of view of the optical sensor. The jet of fluid from the nozzle may be turbulent, and cause turbulence on the area where it hits the transparent screen, which in its turn may obstruct the image captured by the optical sensor and result in a blurry image, which is undesired. However, allowing the fluid hitting the screen to flow down the screen by the force of gravity will allow the fluid to flow down the screen in an even flow, with minimal turbulence. Moreover, spraying the fluid directly onto the transparent screen may ensure that the fluid is evenly spread out on the screen which is advantageous since it provides a fluid film with an even thickness. In this way, the optical sensor may capture an image through the transparent screen and the fluid film, where the fluid film will not obstruct the captured image.

[0026] According to an exemplifying embodiment of the present disclosure, the at least one nozzle is a plurality of nozzles.The plurality of nozzles may be distributed along the length of the top side of the transparent screen. This is advantageous in that it may ensure that the fluid reaches the entirety of the transparent screen, such that the fluid film is formed over the entire area of the transparent screen. According to an exemplifying embodiment of the present disclosure, the plurality of nozzles are evenly distributed along a length L of the transparent screen. The flow rate of the fluid flowing along the transparent screen may be largest the closer to the nozzle. By arranging a plurality of nozzles evenly distributed along the length of the screen may ensure that soil or dirt sticking to the transparent screen may be removed by the fluid film regardless of where on the transparent screen the dirt sticks. Further, by arranging the plurality of nozzles evenly along the length of the transparent screen, the average value of the flow rate may be similar across the area of the transparent screen.

[0027] According to an exemplifying embodiment of the present disclosure, the fluid supply comprises a manifold with a plurality of channels, wherein each channel leads to a nozzle in the plurality of nozzles. Therefore, the plurality of nozzles may all be connected to the same fluid supply. Each nozzle may be connected to an individual "pipe" in the manifold. By providing each nozzle with an individual pipe in the manifold, and connecting the manifold to the fluid supply, the fluid pressure may be evenly distributed over the plurality of nozzles. This enables the fluid to be distributed to the plurality of nozzles with similar flow rate. If the fluid pressure over the plurality of nozzles is uneven, the fluid may be distributed over the transparent screen with different flow rates, possible leading to an uneven distribution of fluid over the transparent screen, which may cause turbulence on the transparent screen.

[0028] According to an exemplifying embodiment of the present disclosure, the fluid supply is configured to provide the washing fluid with a constant flow rate. The fluid supply may provide the at least one nozzle or plurality of nozzles continuously, such that a uniform fluid film is provided on the transparent screen. Moreover, the constant flow rate enables a smooth fluid film on the transparent screen, decreasing the risk of turbulence in the fluid film disturbing the captured image.

[0029] According to an exemplifying embodiment of the present disclosure, the fluid is water or a water solution. The fluid for the fluid film on the transparent screen may be the same fluid as the washing fluid. Therefore, according to an exemplifying embodiment of the present disclosure, the fluid supply for washing fluid is also the fluid supply of the screen assembly. This is advantageous in that the screen assembly may be installed without the need of adding additional fluid supplies in order to make it work. Moreover, according to an exemplifying embodiment of the present disclosure, the fluid flowing along the transparent screen of the screen assembly is collected by the drain of the dishwasher. Since the at lesat one nozzle or plurality of nozzles are installed in the washing cavity, the fluid flowing off the bottom side of the transparent screen may be collected in the bottom of the washing cavity and drained by the drain in the washing cavity.

[0030] According to an exemplifying embodiment of the present disclosure, the fluid is compressed air. In this example, the fluid supply may be an independent fluid supply, providing the at lesat one nozzle or the plurality of nozzles with compressed air. The compressed air may be sprayed from a top of the transparent screen towards the bottom side of the transparent screen, forming a curtain of air immediately in front of the transparent screen. The dirt or soil splashing up towards the transparent screen may then be caught by the air curtain and sprayed down towards the bottom of the washing cavity. Thereby, the transparent screen is kept free from dirt or soil, and the field of view of the optical sensor free from obstructions.Brief Description of the drawings

[0031] Exemplifying embodiments will now be described in more detail, with reference to the following appended drawings, in which: Figures 1a-b illustrate perspective views of a dishwasher according to exemplifying embodiments of the present disclosure; Figures 2a-c illustrate perspective views of a screen assembly according to exemplifying embodiments of the present disclosure; Figure 3 illustrates a side view of the screen assembly installed in a dishwasher according to an exemplifying embodiment of the present disclosure; Figures 4a-b illustrate a schematic view of a soiled and a cleaned transparent screen according to exemplifying embodiments of the present disclosure; Detailed description

[0032] As illustrated in the figures, the size of the elements and regions may be exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of the embodiments. Like reference numerals refer to like elements throughout.

[0033] Exemplifying embodiments will now be described more fully hereinafter with reference to the accompanying figures, in which currently preferred embodiments are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

[0034] With reference to Fig. 1a, a perspective view of a dishwasher 100 according to exemplifying embodiments of the present disclosure is shown. The dishwasher 100 may be suitable for washing, rinsing and drying and dishes, and different washing cycles may be available to choose from. The dishwasher 100 comprises a washing cavity 110 in which a washware support 120 is installed. The washware support 120 comprises a rack loaded with washware 121. The washware 121 may for example be dishes, glasses, bowls, plates, utensils, tools, pans, etc. The washware support 120 is slidably arranged in the washing cavity 110, such that an operator (not shown) may remove the washware support 120 from the washing cavity 110 to empty clean washware 121 from the washware support 120, or load the washware support 120 with soiled washware 121. The washing cavity 110 can be closed with a door 130. When the door 130 is closed, the washing cavity 110 is sealed, and an operator is prevented from accessing the washing cavity 110. When the door 130 is opened, the washing cavity 110 is accessible for an operator. The washing cavity 110 comprises a lighting source 113, for example a lamp. The lighting source 113 may be turned on when the door 130 is opened, or when the door 130 is closed and the washing cycle is running, to illuminate the washing cavity 110.

[0035] Moreover, the dishwasher 100 comprises a screen assembly 200. The screen assembly 200 is installed in a side wall 101 of the dishwasher 100. In the example embodiment shown in fig. 1a, the screen assembly 200 is arranged on an outside of the washing cavity 110. The screen assembly 200 comprises a sealed housing 210. The sealed housing 210 has a substantially rectangular shape, wherein a wall 211 of the sealed housing 210 is installed in the side wall 101 of the dishwasher 100. The wall 211 of the sealed housing 210 comprises a transparent screen 220. The side wall 101 of the dishwasher 100 may comprise a recessed portion where the wall 211 of the sealed housing 210 is installed. The sealed housing 210 houses an optical sensor 320, for example a camera. The sealed housing 210 provides protection for the optical sensor 320, preventing dirt, soil or liquids (not shown) from coming into contact with it. The optical sensor 320 is configured to capture images of the washing cavity 110. A photographic lens (not shown) of the optical sensor 320 may therefore be directed towards the washing cavity 110, such that the photographic lens may capture an image through the transparent screen 220. Because of its placement and direction inside the sealed housing 210, the optical sensor 320 has a field of view 321 covering the washing cavity 110. The field of view 321 of the optical sensor 320 therefore at least partially coincides with the area of the transparent screen 220, such that the transparent screen 220 does not obstruct optical sensor's 320 field of view 321. The transparent screen 220 may for example be made from a transparent glass or a transparent plastic. The optical sensor 320 may capture one or a plurality of images of the washing cavity 110 before, during, or after the washing cycle has been completed. The captured images (not shown) may be continuously fed to an intelligent system (not shown) via a control unit (not shown) to be analysed. The outcome of the analysis may comprise a decision regarding which washing cycle to run on the washware 121 currently loaded in the washware support 120. Different washware 121 may have different characteristics, for example depending on material, size, shape, etc. It may therefore be advantageous to choose a washing cycle based on the characteristics of the washware 121. The intelligent system may help making this decision with the input from the optical sensor 320. The lighting source 113 may be turned on inside the washing cavity 110 when the optical sensor 320 captures images, to ensure that the washware 121 is visible.

[0036] Turning now to fig. 1b, a dishwasher 100 is shown without the washware support 120. The washing cavity 110 comprises a drain 111, arranged in a bottom side 102 thereof. The drain 111 is confiugred to drain liquids from the washing cavity 110, which may be collected on the bottom side 102 of the washing cavity. For example, a washing fluid (not shown) which is supplied to the washing cavity 110 for cleaning the washware 121, may flow down to the bottom side 102 and to the drain 111. The dishwasher 100 is connected to a fluid supply 140, providing the washing cavity 110 with fluids, for example washing fluid, rinsing fluid, and a fluid (not shown) to the screen assembly 200. The fluid supply 140 may for example be a main water supply line. Moreover, there is a dishwasher arm 112 arranged in the bottom side 102 of the washing cavity 110. The dishwasher arm 112 is connected to the fluid supply 140 and may comprise one or more nozzles (not shown) for spraying water into the washing cavity 110. The dishwasher arm 112 may be rotatable, in order for the washing fluid and / or rinsing fluid to reach the entirety of the washing cavity 110.

[0037] In the exemplifying embodiment illustrated in fig. 1b, the screen assembly 200 is arranged inside the washing cavity 110. The screen assembly 200 comprises a sealed housing 210, why the optical sensor 320 housed inside the sealed housing 210 is protected from the washing fluid, rinsing fluid, and fluid supplied to the transparent screen 220. The screen assembly 200 may be arranged anywhere inside the washing cavity 110 where the optical sensor's 320 field of view 321 covers the at least one washware support 120 arranged therein.

[0038] Figure 2a illustrates a perspective view of a screen assembly 200 according to exemplifying embodiments of the present disclosure. The screen assembly 200 comprises a sealed housing 210, wherein one of the walls 211 is formed by the transparent screen 220. Inside the sealed housing 210 there is an optical sensor 320 arranged. The optical sensor 320 is directed with it's photographic lens towards the transparent screen 220, such that the field of view 321 of the optical sensor 320 at least partially coincides with the transparent screen 220. The optical sensor 320 may therefore capture images through the transparent screen 220, such that the transparent screen 220 functions as a protective screen without obstructing or impairing the quality of the captured image. The screen assembly 200 further comprises at least one nozzle 230 arranged at a top side 221 of the transparent screen 220. In the exemplifying embodiment shown in fig. 2a, the at least one nozzle 230 is a plurality of nozzles 230. The plurality of nozzles 230 are distributed along the lenght L of the transparent screen 220. The nozzles 230 may be evenly distributed along the length L, or distributed with different distances between them. The nozzles 230 are configured to deliver a fluid 400 on a surface of the transparent screen 220. The nozzles 230 are connected to a pipe 141, which is connected to a fluid supply 140. The fluid supply 140 providing the screen assembly 200 with fluid may be the same fluid supply 140 for supplying the washing cavity 110 with fluid. The nozzles 230 are oriented in a way such that the fluid 400 is delivered onto the surface of the transparent screen 220. The fluid 400 flows downwards from the top side 221 of the transparent screen 220 towards the bottom side 222 of the transparent screen 220. The fluid 400 flows along the surface of the transparent screen 220 due to the force of gravity, and the transparent screen 220 is vertically arranged. The fluid 400 is continuously delivered on to the transparent screen 220, forming a fluid film 400 thereon. The fluid film 400 is therefore maintained on the transparent screen 220 throughout the duration of the washing cycle, or a predetermined period when the optical sensor 320 is programmed to capture images. The fluid film 400 prevents dirt, soil or debris from sticking to the transparent screen 220, obstructing the image captured by the optical sensor 320. The fluid 400 delivered from the fluid supply 140 to the nozzles 230 may be water, or a water solution, for example. The fluid 400 flowing down the transparent screen 220 may bring debris, soil or dirt along with it on its way from the top side 221 to the bottom side 222, ensuring that the transparent screen 220 remains transparent for the optical sensor 320 to capture an image through.

[0039] Figure 2b illustrates a perspective view of a screen assembly 200 according to an exemplifying embodiment of the present disclosure. The nozzles 230 are connected to a manifold 160 which is connected to the fluid supply 140. The fluid supply 140 delivers fluid to the manifold 160, which is divided into a plurality of individual channels 160a, 160b, 160c, 160d, 160e, 160f, which each are connected to a nozzle 230. In this example, the fluid 400 delivered from the fluid supply 140 may maintain the same pressure over each individual channel 160a-f, such that the flow rate through each one of the nozzles 230 is substantially equal. The individual channels 160a-f may be evenly distributed along the length L of the transparent screen 220.

[0040] Turning to figure 2c, an exemplifying embodiment of a screen assembly 200 is shown, wherein the fluid delivered to the nozzles 230 is compressed air 410. The compressed air 41 is delivered to the nozzles 230 from a fluid supply for compressed air 420. The fluid supply for compressed air 420 may be a compressed air system, connected to the screen assembly 200. The nozzles 230 are directed such that the compressed air 410 is sprayed in front of the transparent screen 220, from a top side 221 towards a bottom side 222 thereof. The compressed air 410 forms a fluid film, or an air curtain 410 in front of the transparent screen 220. The compressed air 410 is continuously supplied through the nozzles 230 such that the air curtain 410 is maintained throughout the duration of the washing cycle, or a predetermined period when the optical sensor 320 is programmed to capture images. The air curtain 410 may prevent debris, soil or other dirt from reaching the transparent screen 220. Instead, the dirt, soil or debris may be caught by the air curtain 410 being sprayed downwards, and therefore the dirt, debris or soil may follow the air curtain 410 downwards to the bottom 102 of the washing cavity 110.

[0041] With reference to fig. 3, a side view of the of the screen assembly 200 installed in a dishwasher 100 according to an exemplifying embodiment of the present disclosure is shown. The sealed housing 210 is seen housing an optical sensor 320, the optical sensor 320 directed with the photographic lens facing the transparent screen 220. On the other side of the transparent screen 220, outside of the sealed housing 210, a washware support 120 is placed, loaded with washware 121. The washware support 120 is placed inside the washing cavity (not shown in the present figure). The screen assembly 200 is connected to the fluid supply 140, and a pipe 141 leading to a nozzle 230. The nozzle 230 is arranged in front of the transparent screen 220 outside of the sealed housing 210. The nozzle 230 sprays a fluid 400 towards the transparent screen 220. The jet of fluid 400 coming from the nozzle 230 hits the transparent screen 220 and flows down on the transparent screen 220, from a top side 221 to a bottom side 222 thereof, forming a fluid film 400. The optical sensor 320 may therefore capture an image of the washware support 120 and the washware 121, throught the transparent screen 220 and the fluid film 400.

[0042] With reference to figs. 4a and 4b, a schematic view of a soiled (fig. 4a) and a cleaned (fig. 4b) transparent screen 220 according to exemplifying embodiments of the present disclosure are shown. In figure 4a, a front view of a transparent screen 220 is shown, where no fluid film is present. The optical sensor 320 may be seen through the transparent screen 220, which is arranged in the foreground of the present figure. Dirt, soil and debris 600 is stuck on the transparent screen 220, obstructing the field of view 321 of the optical sensor 320. The image captured by the optical sensor 320 may therefore be unusable by the intelligent system (not shown), or contribute to a faulty or misleading result. The control unit (not shown) may be configured to sort out images with poor quality. However, if too many images are sorted out, there may not be enough image data for the intelligent system to be able to analyse and suggest a washing cycle on, resulting in poor use of the intelligent system and non-reliable results. A non-reliable result may for example be that the intelligent system suggests a washing cycle to the control unit that leads to non-satisfying washing results, for example dirty washware or damaged washware. Moreover, an image containing obstructions from dirt on the transparent screen 220 may lead to that the control unit comprising the intelligent system makes an erroneous analysis, mistaking the obstructions for washware 121.

[0043] Turning to figure 4b, a front view of a transparent screen 220 with a fluid film 400 present is shown. The optical sensor 320 may be seen through the transparent screen 220, which is arranged in the foreground of the present figure. The fluid film 400 is visible, flowing downwards from a top side 221 towards a bottom side 222 of the transparent screen 220. The dirt, soil and debris 600 that was stuck on the transparent screen 220 in the previous figure, fig. 4a, has instead of getting stuck on the transparent screen 220, followed the fluid film 400 downwards to the bottom side 222. It is clearly seen that the field of view 321 of the optical sensor 320 is free from obstructions caused by debris, soil and dirt 600. The image captured by the optical sensor 320 may therefore be provided to the intelligent system through the control unit, which will analyse the image and provide a reliable analysis, and a trustworthy result.

[0044] Although features and elements are described above in particular combinations, each feature or element can be used alone without the other features and elements or in various combinations with or without other features and elements.

[0045] Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the figures, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage.

Examples

Embodiment Construction

[0032]As illustrated in the figures, the size of the elements and regions may be exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of the embodiments. Like reference numerals refer to like elements throughout.

[0033]Exemplifying embodiments will now be described more fully hereinafter with reference to the accompanying figures, in which currently preferred embodiments are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

[0034]With reference to Fig. 1a, a perspective view of a dishwasher 100 according to exemplifying embodiments of the present disclosure is shown. The dishwasher 100 may be suitable for washing, rinsing and drying and dishes, and different washing cycles may be available to choose from. ...

Claims

1. A screen assembly (200) for preventing soiling of an optical sensor (320) in a dishwasher (100) having a washing cavity (110) and at least one washware support (120) for receiving washware (121), the screen assembly (200) comprising: a sealed housing (210) configured to house the optical sensor (320), the sealed housing (210) comprising at least one wall (211); a transparent screen (220) arranged in the at least one wall (211) of said sealed housing (210); at least one nozzle (230) arranged at a top side (221) of the transparent screen (220) and configured to deliver a fluid (400) on a surface (220s) of the transparent screen (220); a fluid supply (140) arranged to provide a continuous flow of fluid to the at least one nozzle (230); wherein a fluid film (400) is formed on the transparent screen (220), flowing along the surface (220s) of the transparent screen (220) from the top side (221) to a bottom side (222) thereof, and wherein the optical sensor (320) is arranged to capture an image of the washing cavity (110) through the transparent screen (220) and the fluid film (400).

2. The screen assembly (200) according to claim 1, wherein the at least one nozzle (230) is a plurality of nozzles.

3. The screen assembly (200) according to claim 2, wherein the plurality of nozzles are evenly distributed along a length (L) of the transparent screen (220).

4. The screen assembly (200) according to claim 2 or 3, wherein the fluid supply (140) comprises a manifold (160) with a plurality of channels (160a, 160b, 160c, 160d, 160e, 160f), wherein each channel leads to a nozzle (230) in the plurality of nozzles.

5. The screen assembly (200) according to any one of the preceding claims, wherein the at least one nozzle (230) is arranged on an outside of the sealed housing (210), inside the washing cavity (110).

6. The screen assembly (200) according to any one of the preceding claims, wherein a field of view (321) of the optical sensor (320) at least partially coincides with an area of the transparent screen (220).

7. The screen assembly (200) according to any one of the preceding claims, wherein the optical sensor (320) is a camera.

8. The screen assembly (200) according to any one of the preceding claims, wherein the fluid is water or a water solution.

9. The screen assembly (200) according to any of the claims 1 to 7, wherein the fluid is compressed air.

10. A dishwasher (100) comprising a screen assembly (200) according to claim 1, the dishwasher (100) comprising: a washing cavity (110); a washware support (120) configured to receive washware (121); a drain (112) arranged in a bottom of the washing cavity (110) and configured to drain a fluid from the washing cavity (110); and a fluid supply (140) for washing fluid configured to provide the washing cavity (110) with a washing fluid; a detergent configured to clean the washware (121) loaded in the washware support (120); an optical sensor (320) arranged in the screen assembly (200) and configured to capture an image of the washing cavity (110); and a control unit connected to the optical sensor (320); wherein the control unit is configured to, based on information from the image captured by the optical sensor (320), control a washing cycle of the dishwasher (100) to clean the washware (121) in the washware support (120).

11. The dishwasher (100) according to claim 10, wherein the fluid supply (140) for washing fluid is also the fluid supply (140) of the screen assembly (200).

12. The dishwasher (100) according to claim 10 or 11, wherein the washing fluid is water or a water solution.

13. The dishwasher (100) according to any one of the preceding claims, wherein the fluid flowing along the transparent screen (220) of the screen assembly (200) is collected by the drain (112) of the dishwasher (100).

14. The dishwasher (100) according to any one of the preceding claims, wherein the sealed housing (210) of the screen assembly (200) is arranged in the washing cavity (110).

15. The dishwasher (100) according to any one of claims 10 to 12, wherein the fluid supply (140) is configured to provide the washing fluid with a constant flow rate.

16. The dishwasher (100) according to any one of claims 10 to 15, further comprising a light source for illuminating the washing cavity (110).

17. The dishwasher (100) according to any one of claims 10 to 16, wherein the image captured by the optical sensor (320) contains information regarding a characteristic of the washware (121), wherein the characteristic is at least one of a material of the washware (121), a type of washware (121), and a presence of soil on the washware (121).

18. The dishwasher (100) according to claim 17, wherein the control unit is configured to, based on the characteristic of the washware (121), choose a washing cycle from a list of available washing cycles.

Images