Dish washer

Abstract

The present invention relates to a dishwasher. A dishwasher according to one embodiment of the present invention comprises: a tub having a washing chamber formed therein for storing objects to be washed; a door provided on one side of the tub for opening and closing the washing chamber; a rack disposed inside the washing chamber for storing objects to be washed; a nozzle disposed at the bottom of the rack for spraying washing water onto objects to be washed; a detection camera disposed inside the washing chamber that captures an area where washing water is sprayed by the nozzle and generates a plurality of detection images; and a controller that controls the operation of the nozzle, determines whether the nozzle is constrained based on the plurality of detection images received from the detection camera, and performs a constraint response operation based on whether the nozzle is constrained.

Description

Technology Field

[0001] The present invention relates to a dishwasher. Background Technology

[0003] A dishwasher is a home appliance that removes foreign substances remaining on objects to be cleaned, such as dishes or cooking utensils, by spraying water onto them.

[0004] Such dishwashers typically include a tub providing a washing space, a rack provided within the tub for accommodating dishes, a nozzle for spraying wash water onto the rack, a sump for storing wash water, and a wash pump for supplying wash water stored in the sump to the nozzle.

[0005] The nozzle rotates to evenly spray cleaning water onto the objects being cleaned. However, if an object is positioned within the nozzle's rotational range, the nozzle may become constrained and unable to rotate smoothly. Additionally, if contaminants accumulate excessively on the filter surrounding the cleaning pump, the nozzle may become constrained at a specific location and fail to rotate smoothly due to factors such as the inability of the cleaning water supplied by the pump to reach the nozzle. If the nozzle becomes constrained and fails to rotate due to such causes, cleaning water may be sprayed only onto certain areas of the objects being cleaned, potentially degrading the dishwasher's cleaning performance.

[0006] In order to solve the problem caused by the nozzle not rotating smoothly as described above, an embodiment of a dishwasher capable of detecting whether the nozzle is rotating is disclosed in US 2018-0008119 A1.

[0007] The dishwasher according to the above literature determines whether the nozzle is constrained based on the water stream entering a sensor located on the inner side of the door. However, the dishwasher according to the above literature cannot distinguish whether the water stream entering the sensor is due to washing water sprayed by the nozzle, water stream flowing along the wall, or condensed washing water. As a result, the dishwasher according to the above literature has a problem in that it is difficult to accurately determine whether the nozzle is constrained due to the influence of the water stream entering the sensor, regardless of the rotation of the nozzle.

[0008] Therefore, there is a need to develop a dishwasher capable of more accurately detecting whether the nozzle is constrained. The problem to be solved

[0010] The objective of the present invention is to provide a dishwasher capable of accurately detecting whether the nozzle is constrained.

[0011] In addition, the objective of the present invention is to provide a dishwasher capable of minimizing the degradation of cleaning performance even if the nozzle is constrained and does not rotate smoothly.

[0012] The objects of the present invention are not limited to those mentioned above, and other unmentioned objects and advantages of the present invention may be understood from the following description and will be more clearly understood by the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. means of solving the problem

[0014] In the present invention, the dishwasher includes a detection camera that captures an area where washing water is sprayed by a nozzle and generates a plurality of detection images, and a controller that determines whether the nozzle is constrained based on the plurality of detection images received from the detection camera and performs a constraint response operation based on whether the nozzle is constrained.

[0015] With this configuration, it is possible to accurately detect whether the nozzle is constrained, and even if the nozzle is constrained and does not rotate smoothly, the degradation of cleaning performance can be minimized.

[0016] According to one embodiment of the present invention, the apparatus comprises: a tub having a cleaning chamber formed therein for storing a cleaning object; a door provided on one side of the tub for opening and closing the cleaning chamber; a rack disposed inside the cleaning chamber for storing the cleaning object; a nozzle disposed at the bottom of the rack for spraying cleaning water onto the cleaning object; a detection camera disposed inside the cleaning chamber that captures an area where the cleaning water is sprayed by the nozzle and generates a plurality of detection images; and a controller that controls the operation of the nozzle, determines whether the nozzle is constrained based on the plurality of detection images received from the detection camera, and performs a constraint response operation based on whether the nozzle is constrained.

[0017] In addition, in one embodiment of the present invention, the detection camera is positioned on the inner side of the tub or on the inner side of the door, and is positioned at a height capable of capturing the upper part of the rack.

[0018] In addition, in one embodiment of the present invention, the controller generates a plurality of water stream images by removing a background image from each of the plurality of detection images, and determines whether the nozzle is constrained based on the water streams included in the plurality of water stream images.

[0019] In addition, in one embodiment of the present invention, the controller uses an image captured by the detection camera as the background image before spraying the cleaning water through the nozzle.

[0020] In addition, in one embodiment of the present invention, the controller uses the average image of the plurality of detected images as the background image.

[0021] In addition, in one embodiment of the present invention, the controller determines that the nozzle is constrained when a water stream is continuously detected in a specific area of ​​the plurality of water stream images.

[0022] In addition, in one embodiment of the present invention, the controller calculates the direction vector of the water stream included in the plurality of detection images and determines whether the nozzle is constrained based on the direction vector of the water stream.

[0023] In addition, in one embodiment of the present invention, the controller determines that the nozzle is constrained if the direction vector of the water stream is continuously detected in a specific area of ​​the plurality of detection images.

[0024] In addition, in one embodiment of the present invention, if the controller determines that the nozzle is constrained, it changes the rotation direction of the nozzle.

[0025] In addition, in one embodiment of the present invention, when the controller determines that the nozzle is constrained, it controls the interface to transmit an abnormality notification to a user terminal or output an abnormality notification.

[0026] In addition, in one embodiment of the present invention, if the controller determines that the nozzle is constrained, it increases the operating time of the nozzle.

[0027] In addition, in one embodiment of the present invention, the nozzle of the dishwasher includes a first nozzle and a second nozzle, and when the controller determines that the first nozzle is constrained, it decreases the operating time of the first nozzle and increases the operating time of the second nozzle, and when the controller determines that the second nozzle is constrained, it increases the operating time of the first nozzle and decreases the operating time of the second nozzle. Effects of the invention

[0029] The dishwasher according to the present invention has the advantage of being able to accurately detect whether the nozzle is constrained by determining whether the nozzle is constrained based on a plurality of detection images received from a detection camera.

[0030] In addition, the dishwasher according to the present invention performs a constraint-correcting operation based on whether the nozzle is constrained, so it has the advantage of minimizing the degradation of washing performance even if the nozzle is constrained and does not rotate smoothly.

[0031] In addition to the effects described above, the specific effects of the present invention are described together with the specific details for implementing the invention below. Brief explanation of the drawing

[0033] FIG. 1 is a perspective view illustrating a dishwasher according to one embodiment of the present invention. Figure 2 is a cross-sectional view along the "AA" line of Figure 1. Figure 3 is a cross-sectional view along the "BB" line of Figure 1. FIG. 4 is a flowchart for explaining the operation of a dishwasher according to one embodiment of the present invention. FIG. 5 is a flowchart illustrating a method for a dishwasher according to an embodiment of the present invention to determine whether a nozzle is constrained based on a plurality of detection images. FIG. 6 is a diagram showing an example of a detection image according to an embodiment of the present invention. FIG. 7 is a drawing showing an example of a background image according to an embodiment of the present invention. FIG. 8 is a drawing showing an example of a water stream image according to an embodiment of the present invention. FIG. 9 is a diagram showing an image divided into a plurality of regions according to an embodiment of the present invention. FIG. 10 is a diagram showing the state of displaying the direction vector of a water stream detected in a detection image according to one embodiment of the present invention. FIG. 11 is a graph showing the ratio of water streams included in a specific area of ​​a plurality of water stream images according to one embodiment of the present invention. Specific details for implementing the invention

[0034] The aforementioned objectives, features, and advantages are described in detail below with reference to the attached drawings, thereby enabling those skilled in the art to easily implement the technical concept of the present invention. In describing the present invention, detailed descriptions of known technologies related to the present invention are omitted if it is determined that such descriptions would unnecessarily obscure the essence of the invention. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0035] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0036] In the following, the statement that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0037] In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be directly connected or connected to each other, another component may be "interposed" between each component, or each component may be "connected," "combined," or "connected" through another component.

[0038] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0039] Singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "composed of" or "comprising" should not be interpreted as necessarily including all of the various components or steps described in the specification, and should be interpreted as meaning that some of the components or steps may be omitted or additional components or steps may be included.

[0040] Hereinafter, a dishwasher according to some embodiments of the present invention will be described.

[0041] FIG. 1 is a perspective view illustrating a dishwasher according to one embodiment of the present invention.

[0042] Referring to FIG. 1, a perspective view showing the exterior of a dishwasher (100) according to one embodiment of the present invention can be seen. A dishwasher (100) according to one embodiment of the present invention may include a case (101) and a door (120).

[0043] The case (101) forms the exterior of the dishwasher (100). The case (101) may be formed in the shape of a cuboid with one side open, and an empty space is formed inside the case (101).

[0044] A door (120) is provided on an open side of the case (101) to open and close an empty space inside the case (101). The door (120) can be opened and closed automatically or manually.

[0045] The configuration placed in the empty space inside the case (101) can be described using the cross-sectional views of FIGS. 2 and FIGS. 3.

[0046] FIG. 2 is a cross-sectional view along the line "AA" in FIG. 1. FIG. 3 is a cross-sectional view along the line "BB" in FIG. 1.

[0047] Referring to FIGS. 2 and 3, a dishwasher (100) according to one embodiment of the present invention includes a tub (110), a door (120), a rack (130), a nozzle (140), and a detection camera (150). Although not shown in the drawings, the dishwasher (100) according to one embodiment of the present invention includes a controller. The dishwasher (100) according to one embodiment of the present invention may further include a wash water supply unit (160).

[0048] The tub (110) is provided inside the case (101) and can be formed in the shape of a cuboid with one side open. The open side of the tub (110) can be opened and closed by a door (120). A cleaning chamber (111) in which a cleaning object is stored is formed inside the tub (110).

[0049] The door (120) opens and closes the open side of the tub (110). That is, the door (120) is provided on the open side of the tub (110) to open and close the washing room.

[0050] A washing water supply unit (160) is positioned at the lower side of the tub (110) and supplies washing water to the nozzle (140). Such a washing water supply unit (160) may comprise a sump in which washing water is stored, a washing pump that supplies washing water stored in the sump to the nozzle (140), a heater that heats the washing water inside the washing pump, a valve that controls the flow of washing water, and piping through which washing water flows.

[0051] A rack (130) is placed inside a washing room (111) and stores objects to be washed. The rack (130) may include a first rack (130a) and a second rack (130b). The first rack (130a) may be placed at the top of the washing room (111), and the second rack (130b) may be placed at the bottom of the washing room (111).

[0052] The nozzle (140) is positioned inside the washing chamber (111) and rotates to spray washing water onto the washing target. The nozzle (140) may include a first nozzle (140a), a second nozzle (140b), and a third nozzle (140c).

[0053] The first nozzle (140a) is positioned at the bottom of the first rack (130a) and can spray washing water upward. That is, the first nozzle (140a) can spray washing water onto a washing target stored in the first rack (130a). At this time, the first nozzle (140a) can rotate due to the repulsive force of the washing water supplied from the washing water supply unit (160) and spray washing water onto the washing target.

[0054] The second nozzle (140b) is positioned at the bottom of the second rack (130b) and can spray washing water upward. That is, the second nozzle (140b) can spray washing water onto a washing target stored in the second rack (130b). At this time, the second nozzle (140b) can rotate due to the repulsive force of the washing water supplied from the washing water supply unit (160) and spray washing water onto the washing target.

[0055] The third nozzle (140c) is positioned at the top of the first rack (130a) and can spray cleaning water downward. That is, the third nozzle (140c) can spray cleaning water onto the cleaning objects housed in the first rack (130a) and the second rack (130b). At this time, the third nozzle (140c) can rotate due to the repulsive force of the cleaning water supplied from the cleaning water supply unit (160) and spray cleaning water onto the cleaning objects.

[0056] The following description focuses on an embodiment for determining whether the first nozzle (140a) and the second nozzle (140b) are constrained, but the present invention is not limited thereto, and an embodiment described later may be similarly used to determine whether the third nozzle (140c) is constrained.

[0057] A detection camera (150) is positioned inside the washing room (111) and captures an area where washing water is sprayed by a nozzle (140), thereby generating multiple detection images.

[0058] The detection camera (150) can generate a detection image by capturing an area where cleaning water is sprayed. At this time, the image captured by the detection camera (150) includes a number of detection images corresponding to the number of frames per second of the detection camera (150). That is, the detection camera (150) can generate a detection image by capturing an area where cleaning water is sprayed, and can generate multiple detection images based on the generated detection image. The detection camera (150) can transmit the multiple detection images to a controller described later.

[0059] The detection camera (150) can be positioned in a location that facilitates capturing the area where the cleaning water is sprayed. The detection camera (150) can be positioned on the inner side of the door (120) as shown in FIG. 2. Additionally, the detection camera (150) can be attached to the inner side of the tub (110) as shown in FIG. 3. Although FIG. 2 and FIG. 3 show the detection camera (150) protruding in the direction of the cleaning room (111) from the inner side of the door (120) or the tub (110), the present invention is not limited thereto. That is, unlike FIG. 2 and FIG. 3, the detection camera (150) may be in a form that is recessed into the inner side of the door (120) or the tub (110).

[0060] The detection camera (150) may include a first detection camera (150a) and a second detection camera (150b).

[0061] The first detection camera (150a) can photograph the area where cleaning water is sprayed by the first nozzle (140a). To this end, the first detection camera (150a) can be positioned at a height capable of photographing the upper part of the first rack (130a), which is the area where cleaning water is sprayed by the first nozzle (140a).

[0062] The second detection camera (150b) can photograph the area where cleaning water is sprayed by the second nozzle (140b). To this end, the second detection camera (150b) can be positioned at a height where it can photograph the upper part of the second rack (130b), which is the area where cleaning water is sprayed by the second nozzle (140b).

[0063] The controller controls the overall operation of the dishwasher. Such a controller may be implemented by including at least one physical element among ASICs (Application Specific Integrated Circuits), DSPs (Digital Signal Processors), DSPDs (Digital Signal Processing Devices), PLDs (Programmable Logic Devices), FPGAs (Field Programmable Gate Arrays), controllers, microcontrollers, and microprocessors.

[0064] The controller controls the operation of the nozzle (140). At this time, the controller can control the rotational movement of the nozzle (140) by adjusting the amount of washing water supplied from the washing water supply unit (160) to the nozzle (140) to control the repulsive force of the washing water sprayed from the nozzle (140).

[0065] Then, the controller determines whether the nozzle (140) is constrained based on a plurality of detection images received from the detection camera (150), and performs a constrained corresponding operation based on whether the nozzle (140) is constrained.

[0066] The operation of the controller in more detail can be explained with reference to FIG. 4.

[0067] FIG. 4 is a flowchart for explaining the operation of a dishwasher according to one embodiment of the present invention.

[0068] Referring to FIG. 4, first, the controller sprays cleaning water through the nozzle (140) (S410). The controller can cause the nozzle (140) to rotate and spray cleaning water by supplying cleaning water from the cleaning water supply unit (160) to the nozzle (140).

[0069] Then, the controller captures the area where the cleaning water is sprayed through the detection camera (150) (S420). The controller can capture the upper part of the rack (130), which is the area where the cleaning water is sprayed through the nozzle (140), through the detection camera (150).

[0070] Then, the controller receives multiple detection images from the detection camera (150) (S430). At this time, the number of multiple detection images received by the controller from the detection camera (150) may be greater than the value obtained by dividing the number of frames per second of the detection camera (150) by the number of rotations per second of the nozzle (140).

[0071] For example, if the frame rate per second of the detection camera (150) is 60fps and the rotation rate per second of the nozzle (140) is 4 turns, the number of frames captured by the detection camera (150) when the nozzle (140) rotates one turn is 15. That is, if the controller receives a number of detection images greater than the value obtained by dividing the frame rate per second of the detection camera (150) by the rotation rate per second of the nozzle (140), it can detect the cleaning water sprayed over the entire upper area of ​​the rack (130) while the nozzle (140) rotates one turn. Accordingly, the controller can accurately determine the nozzle constraint using the detection images.

[0072] After receiving multiple detection images, the controller determines whether the nozzle (140) is constrained based on the multiple detection images (S440).

[0073] The controller can generate multiple water stream images by removing background images from multiple detection images and determine whether the nozzle is constrained based on the water streams included in the multiple water stream images. This can be explained in more detail with reference to FIG. 5.

[0074] FIG. 5 is a flowchart illustrating a method for a dishwasher according to an embodiment of the present invention to determine whether a nozzle is constrained based on a plurality of detection images.

[0075] Referring to FIG. 5, first, the controller generates multiple water stream images by removing the background image from each of the multiple detection images (S510).

[0076] Examples of the detection image, background image, and water stream image can be seen by referring to FIGS. 6 to 8.

[0077] FIG. 6 is a diagram showing an example of a detection image according to an embodiment of the present invention. FIG. 7 is a diagram showing an example of a background image according to an embodiment of the present invention. FIG. 8 is a diagram showing an example of a water stream image according to an embodiment of the present invention.

[0078] Referring to FIG. 6, an example of a detection image can be seen. The detection image is an image received from a detection camera (150) and includes both tableware placed on a rack (130) and a stream of water sprayed from a nozzle (140) as shown in FIG. 6.

[0079] Referring to FIG. 7, an example of a background image can be seen. The background image is an image of tableware placed on a rack (130) before a water stream is sprayed from the nozzle (140), and may include only tableware placed on the rack (130) as shown in FIG. 7.

[0080] The background image may be an image captured by a detection camera (150) before spraying cleaning water through the nozzle (140). That is, the controller receives an image captured by the detection camera (150) before spraying cleaning water through the nozzle (140), and can use the received image as a background image.

[0081] If the controller does not receive an image captured by the detection camera (150) before spraying cleaning water through the nozzle (140), the controller may use the average image of multiple detection images as a background image.

[0082] That is, the controller calculates an average image by calculating the average value of the color values ​​of pixels at the same location from multiple detected images, and can use the average image as a background image. The color values ​​can be one of RGB, CMYK, HSV, HSL, or HEX.

[0083] At this time, the accuracy of the background image can be increased by increasing the number of detection images used in the calculation of the average image. However, since the method of using the average image as the background image is less accurate than the method of using an image captured by the detection camera (150) as the background image before spraying the cleaning water through the nozzle (140), it may be used supplementarily.

[0084] Referring to FIG. 8, an example of a water stream image can be seen. The water stream image is an image generated by removing a background image from a detection image, and includes a water stream sprayed from a nozzle (140) as shown in FIG. 8. Through such a water stream image, the controller can determine which area the water stream is sprayed from the nozzle (140).

[0085] Returning to Fig. 5, after generating multiple water stream images, the controller determines whether a water stream is continuously detected in a specific area of ​​the multiple water stream images (S520).

[0086] The controller can divide the image into multiple regions as shown in Fig. 9.

[0087] FIG. 9 is a diagram showing an image divided into a plurality of regions according to an embodiment of the present invention.

[0088] Referring to FIG. 9, an embodiment in which an image is divided into four regions can be seen. As shown in FIG. 9, the controller can divide the top left of the image into a first region (R1), the top right into a second region (R2), the bottom left into a third region (R3), and the bottom right into a fourth region (R4).

[0089] At this time, since tableware is not placed in the first area (R1), third area (R3), and fourth area (R4) of the image as in FIG. 9, or there is an empty space between the tableware, when a water stream is sprayed into the area through the nozzle (140), the water stream may be included in the area of ​​the water stream image.

[0090] In this situation, if a water stream is continuously detected in the first area (R1), third area (R3), and fourth area (R4) of the water stream image, the controller can determine that the nozzle (140) is constrained and the water stream is continuously sprayed in a specific area.

[0091] In addition, if a water stream is not continuously detected in the first area (R1), third area (R3), and fourth area (R4) of the water stream image, the controller may determine that the nozzle (140) is constrained and the water stream is not continuously sprayed in a specific area.

[0092] And in the second region (R2) of the image as in FIG. 9, tableware is closely arranged and there is no empty space, so even if a water stream is sprayed into that region through the nozzle (140), the water stream cannot be included in that region of the water stream image. That is, regardless of whether the nozzle (140) is constrained, the water stream is not continuously detected in the second region (R2) of the water stream image.

[0093] Returning to Fig. 5, the controller determines whether a water stream is continuously detected in a specific area among the multiple divided regions of the water stream image. The result of water stream detection can be as shown in Fig. 11.

[0094] FIG. 11 is a graph showing the ratio of water streams included in a specific area of ​​a plurality of water stream images according to one embodiment of the present invention.

[0095] Referring to Fig. 11, a graph showing the ratio of a water stream to a specific area over time can be observed. If the ratio in the graph is close to 0, the controller can determine that no water stream has been detected. If the ratio in the graph is far from 0, the controller can determine that a water stream has been detected.

[0096] Graph G1 is a graph showing the case where the water stream is detected at regular intervals and then not detected. If the ratio of the water stream appears as in Graph G1, the controller can determine that the nozzle (140) is not constrained.

[0097] Graph G2 is a graph of the case where the water stream is not continuously detected. If the ratio of the water stream appears as in graph G2, the controller can determine that the nozzle (140) is constrained and the water stream is not continuously detected, or that the water stream is blocked by tableware and the water stream is not continuously detected.

[0098] Graph G3 is a graph of the case where a water stream is continuously detected. If the ratio of the water stream appears as in Graph G3, the controller can determine that the nozzle (140) is constrained and the water stream is continuously detected.

[0099] Graph G4 is a graph of the case where the water stream is detected once and then not detected. If the ratio of the water streams appears as in Graph G4, the controller can determine that the nozzle (140) is not constrained but there is a problem with the rotation speed of the nozzle (140).

[0100] Returning to FIG. 5, the controller determines that the nozzle (140) is constrained if a water stream is continuously detected in a specific area of ​​the multiple water stream images (S530). Conversely, the controller determines that the nozzle (140) is not constrained if a water stream is not continuously detected in a specific area of ​​the multiple water stream images (S540).

[0101] Returning to Fig. 4, in another way, the controller can calculate the direction vector of the water stream included in a plurality of detection images and determine whether the nozzle is constrained based on the direction vector of the water stream.

[0102] The controller can calculate the direction vector of the water stream using two chronologically adjacent detection images among multiple detection images. In this case, the controller can calculate the direction vector of the water stream using optical flow technology.

[0103] The direction vector of the water stream calculated by the controller may be as shown in Fig. 10.

[0104] FIG. 10 is a diagram showing the state of displaying the direction vector of a water stream detected in a detection image according to one embodiment of the present invention.

[0105] Referring to FIG. 10, an example of an image showing the direction vector of a water stream can be seen. In this way, the controller can determine which area the water stream is sprayed from the nozzle (140) by using the direction vector of the water stream obtained in a manner similar to an actual water stream.

[0106] Returning to Fig. 4, the controller determines whether the direction vector of the water stream is continuously detected in a specific area of ​​multiple detection images. Since this is the same as the method for determining whether the water stream is continuously detected in a specific area of ​​multiple water stream images described above, a detailed explanation will be omitted.

[0107] And the controller can determine that the nozzle (140) is constrained if the direction vector of the water stream is continuously detected in a specific area of ​​multiple detection images. Conversely, the controller can determine that the nozzle (140) is not constrained if the direction vector of the water stream is not continuously detected in a specific area of ​​multiple detection images.

[0108] Next, the controller checks whether the nozzle (140) is determined to be constrained (S450), and if it is determined that the nozzle (140) is not constrained, it terminates without further operation because there is no abnormality in the operation of the dishwasher (100).

[0109] And if it is determined that the nozzle (140) is constrained, a constrained response operation is performed (S460).

[0110] The controller can change the rotation direction of the nozzle (140) as a constraint response operation. If the constraint of the nozzle (140) occurs when a light object is positioned within the rotation radius of the nozzle (140), the constraint of the nozzle (140) can be released by changing the rotation direction of the nozzle (140).

[0111] In addition, the controller can transmit an abnormality notification to the user terminal as a constraint response action. For example, the controller can send a message to the user terminal indicating that a nozzle constraint has been detected.

[0112] Additionally, the controller can control an interface (not shown) included in the dishwasher (100) to output an abnormality notification as a constraint response action. For example, the controller can control the interface to display a warning sign or text.

[0113] In this way, by the controller outputting an abnormality notification when the nozzle (140) malfunctions, the user can respond more quickly to the malfunction of the nozzle (140).

[0114] Additionally, the controller can increase the operating time of the nozzle (140) as a constrained response operation. Even if the nozzle (140) is in a constrained state, the controller can increase the operating time of the nozzle (140) so that the washing of the dishes can be done a little longer.

[0115] Additionally, if the controller determines that the first nozzle (140a) is constrained, it can reduce the operating time of the first nozzle (140a) and increase the operating time of the second nozzle (140b) as a constrained response operation. Conversely, if the controller determines that the second nozzle (140b) is constrained, it can increase the operating time of the first nozzle (140a) and decrease the operating time of the second nozzle (140b) as a constrained response operation. In this way, by reducing the operating time of the nozzle (140) determined to be constrained and increasing the operating time of the other nozzle (140), the controller allows the cleaning operation to be performed for a longer period through the nozzle (140) capable of smooth rotation, thereby minimizing the degradation of cleaning performance even if the nozzle (140) is constrained and cannot rotate smoothly.

[0116] The dishwasher (100) according to the present invention as described above determines whether the nozzle (140) is constrained based on a plurality of detection images received from a detection camera (150), so it can accurately detect whether the nozzle (140) is constrained. In addition, since it performs a constrained response operation based on whether the nozzle (140) is constrained, it can minimize the degradation of washing performance even if the nozzle (140) is constrained and does not rotate smoothly.

[0117] Although the present invention has been described above with reference to the illustrated drawings, the present invention is not limited by the embodiments and drawings disclosed in this specification, and it is obvious that various modifications can be made by a person skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration of the present invention were not explicitly described while explaining the embodiments of the present invention above, it is natural to acknowledge that the effects predictable by said configuration should also be recognized. Explanation of the symbols

[0119] 100: Dishwasher 101: Case 120: Door 130a, 130b: Rack 140a, 140b, 140c: Nozzles 150a, 150b: Detection cameras 160: Washing water supply unit

Claims

Claim 1 A dishwasher comprising: a tub having a washing chamber formed therein for storing objects to be washed; a door provided on one side of the tub for opening and closing the washing chamber; a rack disposed inside the washing chamber for storing objects to be washed; a nozzle disposed at the bottom of the rack for spraying washing water onto objects to be washed; a detection camera disposed inside the washing chamber that captures an area where washing water is sprayed by the nozzle and generates a plurality of detection images; and a controller that controls the operation of the nozzle, receives a number of detection images from the detection camera that is greater than the value obtained by dividing the number of frames per second of the detection camera by the number of rotations per second of the nozzle, determines whether the nozzle is constrained based on the received plurality of detection images, and performs a constraint response operation based on whether the nozzle is constrained. Claim 2 A dishwasher according to claim 1, wherein the detection camera is positioned on the inner side of the tub or on the inner side of the door, and is positioned at a height capable of capturing the upper part of the rack. Claim 3 A dishwasher according to claim 1, wherein the controller generates multiple water stream images by removing a background image from each of the multiple detection images and determines whether the nozzle is constrained based on the water streams included in the multiple water stream images, and the controller calculates an average image by calculating the average value of the color values ​​of pixels at the same location of the multiple detection images and uses the average image as the background image. Claim 4 In paragraph 3, the dishwasher in which the controller uses an image captured by the detection camera as the background image before spraying the washing water through the nozzle. Claim 5 delete Claim 6 In paragraph 3, the dishwasher determines that the nozzle is constrained when the controller continuously detects a water stream in a specific area of ​​the plurality of water stream images. Claim 7 A dishwasher according to claim 1, wherein the controller calculates a direction vector of a water stream included in an image using two chronologically adjacent detection images among the plurality of detection images, and determines whether the nozzle is constrained based on the direction vector of the water stream. Claim 8 A dishwasher according to claim 7, wherein the controller determines that the nozzle is constrained if the direction vector of the water stream is continuously detected in a specific area of ​​the plurality of detection images. Claim 9 A dishwasher according to claim 1, wherein the controller changes the rotation direction of the nozzle when it is determined that the nozzle is constrained. Claim 10 A dishwasher according to claim 1, wherein the controller controls the interface to transmit an abnormality notification to a user terminal or output an abnormality notification when it is determined that the nozzle is constrained. Claim 11 A dishwasher according to claim 1, wherein the controller increases the operating time of the nozzle when it determines that the nozzle is constrained. Claim 12 A dishwasher according to claim 1, wherein the nozzle comprises a first nozzle and a second nozzle, and if the controller determines that the first nozzle is constrained, the operating time of the first nozzle is reduced and the operating time of the second nozzle is increased, and if the controller determines that the second nozzle is constrained, the operating time of the first nozzle is increased and the operating time of the second nozzle is reduced.

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