Cooking appliance for detecting contamination of protective window and control method thereof

Abstract

A cooking appliance is disclosed. The cooking appliance according to the present disclosure comprises: a heating unit; a thermal imaging camera which is disposed above a cooking chamber and is for capturing an image of a lower region of the cooking chamber in which a turntable is located in the cooking chamber; a window which is disposed between the turntable of the cooking chamber and the thermal imaging camera and is for protecting the thermal imaging camera from food placed on the turntable; a memory for storing instructions; and at least one processor including processing circuitry. The at least one processor, when the instructions are individually or collectively executed, can: rotate the turntable when the cooking appliance is turned on, and heat the food by using the heating unit; acquire a plurality of thermal images by using the thermal imaging camera while the turntable rotates; identify a plurality of heating areas, which are areas occupied by the food placed on the turntable, in the plurality of thermal images; identify an accumulated heating area corresponding to the plurality of heating areas in an accumulated thermal image acquired by accumulating the plurality of thermal images; generate a circle on the basis of coordinate values of a plurality of pixels selected from the outline of the accumulated heating area in the accumulated thermal image; and identify whether the window is contaminated on the basis of the generated circle.

Description

Cooking device for detecting contamination of a protective window and a method for controlling the same

[0001] The present disclosure relates to a cooking appliance and a method for controlling the same, for detecting contamination of a protective window of a camera embedded in the cooking appliance.

[0002] Cooking appliances, such as microwave ovens, may have a thermal imaging camera built into the cooking chamber. In this case, as the food inside the chamber heats up, the lens of the thermal imaging camera may become contaminated or damaged. To prevent this, a separate protective window may be positioned over the lens to protect it. Alternatively, the protective window may be attached integrally to the lens. If the protective window becomes contaminated, the thermal imaging camera may be unable to accurately measure the temperature of the food inside the chamber. Consequently, the need has arisen for a method to detect when the protective window is contaminated.

[0003] A cooking appliance according to the present disclosure comprises a heating unit; a thermal imaging camera disposed above a cooking chamber and configured to photograph a lower area of ​​the cooking chamber where a turntable is located in the cooking chamber; a window disposed between the turntable of the cooking chamber and the thermal imaging camera to protect the thermal imaging camera from food placed on the turntable; a memory for storing instructions; and at least one processor comprising processing circuitry, wherein when the instructions are executed individually or collectively, the at least one processor rotates the turntable and heats the food using the heating unit, acquires a plurality of thermal imaging images using the thermal imaging camera while the turntable is rotating, identifies a plurality of heating areas in the plurality of thermal imaging images which are areas occupied by food placed on the turntable, identifies a cumulative heating area corresponding to the plurality of heating areas in a cumulative thermal imaging image acquired by accumulating the plurality of thermal imaging images, and the cumulative thermal imaging A circle is generated based on the coordinate values ​​of a plurality of pixels selected from the outline of the accumulated heating area in the image, and the contamination status of the window can be identified based on the generated circle.

[0004] Additionally, when the instructions are executed individually or collectively, the at least one processor can identify the turntable area and the background area outside the turntable area in each of the plurality of thermal images, identify at least one pixel among the pixels included in the turntable area in each of the plurality of thermal images that has a temperature difference from the background area greater than or equal to a preset value, and identify the area including the at least one pixel in the plurality of thermal images as the plurality of heating areas.

[0005] Additionally, when the instructions are executed individually or collectively, the at least one processor binarizes the plurality of thermal images to obtain a plurality of binarized images composed of a first pixel and a second pixel, accumulates the plurality of binarized images to obtain a cumulative thermal image, and identifies an area including the first pixel among the plurality of pixels of the cumulative thermal image as the cumulative heating area.

[0006] Additionally, the at least one processor can acquire the accumulated thermal image by accumulating the plurality of binarized images such that, when the instructions are executed individually or collectively, for pixels at the same location in the plurality of binarized images, if at least one pixel among the pixels is the first pixel, the pixel at the location in the accumulated thermal image becomes the first pixel, and if the pixels are the second pixel, the pixel at the location in the accumulated thermal image becomes the second pixel.

[0007] Additionally, when the instructions are executed individually or collectively, the at least one processor can identify pixels adjacent to the second pixel among a plurality of first pixels included in the accumulated heating area as the outline of the accumulated heating area.

[0008] Additionally, when the instructions are executed individually or collectively, the at least one processor can identify whether the accumulated heating area is the source based on the generated circle, and identify whether the window is contaminated based on whether the accumulated heating area is the source.

[0009] Additionally, when the instructions are executed individually or collectively, the above-mentioned at least one processor can generate a plurality of circles based on at least three pixels selected from among the pixels corresponding to the outline of the accumulated heating area, for each of the generated plurality of circles, identify the ratio of specific pixels to the pixels corresponding to the outline of the accumulated heating area, identify the circle with the largest ratio among the plurality of circles, and for each pixel forming the outline of the identified circle in the identified circle, identify the radius of the identified circle and the difference in distance from the center of the identified circle to the pixel included in the heating area, and if the sum of the distance differences is less than a preset value, identify the accumulated heating area as a circle, and if the accumulated heating area is identified as a circle, identify the window as not contaminated, and if the sum of the distance differences is greater than or equal to a preset value, identify the accumulated heating area as not a circle, and if the accumulated heating area is identified as not a circle, identify the window as contaminated.

[0010] Additionally, when the instructions are executed individually or collectively, the at least one processor can identify, for each of the generated circles, the distance between the pixels corresponding to the outline of the accumulated heating area and the center pixels of the generated circle, and identify the specific pixels among the pixels corresponding to the outline of the accumulated heating area such that the difference between the center pixels of the generated circle and the radius of the generated circle is less than a preset value.

[0011] In addition, when the instructions are executed individually or collectively, the at least one processor can acquire a plurality of thermal images based on the shooting speed of the thermal imaging camera and the time it takes for the turntable to rotate one full revolution, and can identify the accumulated heating area by accumulating the acquired thermal images.

[0012] Additionally, the at least one processor can control the heating unit to stop heating the cooking chamber when the window is identified as contaminated when the instructions are executed individually or collectively.

[0013] A method for controlling a cooking appliance including a heating unit, a turntable, a thermal imaging camera, and a window according to the present disclosure may include the steps of: executing instructions individually or collectively; when the cooking appliance is turned on, rotating the turntable and heating food using the heating unit; acquiring a plurality of thermal images using the thermal imaging camera while the turntable is rotating; identifying a plurality of heating areas in the plurality of thermal images, which are areas occupied by food placed on the turntable; identifying a cumulative heating area corresponding to the plurality of heating areas in a cumulative thermal image acquired by accumulating the plurality of thermal images; generating a circle based on the coordinate values ​​of a plurality of pixels selected from the outline of the cumulative heating area in the cumulative thermal image; and identifying whether the window is contaminated based on the generated circle.

[0014] Additionally, in a non-transient computer-readable recording medium that stores one or more instructions executed by a processor of a cooking device, the operation may include the steps of: rotating a turntable and heating a cooking chamber using a heating unit when the cooking device is turned on; acquiring a plurality of thermal images using a thermal imaging camera while the turntable is rotating; identifying a plurality of heating areas corresponding to food placed on the turntable in the plurality of thermal images; identifying a cumulative heating area corresponding to the plurality of heating areas in a cumulative thermal image acquired by accumulating the plurality of thermal images; generating a circle based on the coordinate values ​​of a plurality of pixels selected from the outline of the cumulative heating area in the cumulative thermal image; and identifying whether the window is contaminated based on the generated circle.

[0015] FIG. 1 is a drawing showing the appearance of a cooking appliance according to at least one embodiment of the present disclosure.

[0016] FIG. 2 is a block diagram showing the configuration of a cooking appliance according to at least one embodiment of the present disclosure.

[0017] FIG. 3 is a block diagram showing the detailed configuration of a cooking appliance according to at least one embodiment of the present disclosure.

[0018] FIG. 4 is a flowchart illustrating a method for controlling a cooking appliance according to at least one embodiment of the present disclosure.

[0019] FIG. 5 is a drawing for explaining a method for identifying a heating area of ​​a cooking chamber according to at least one embodiment of the present disclosure.

[0020] FIGS. 6 to 8 are drawings showing thermal images of a cooking chamber according to at least one embodiment of the present disclosure.

[0021] FIG. 9 is a flowchart illustrating a method for identifying contamination of a protective window that occurs during the operation of a cooking appliance according to at least one embodiment of the present disclosure.

[0022] FIG. 10 is a flowchart illustrating another embodiment for identifying contamination of a protective window according to at least one embodiment of the present disclosure.

[0023] FIGS. 11 and 12 are drawings for explaining a thermal image converted into a polar coordinate system image according to at least one embodiment of the present disclosure.

[0024] FIGS. 13 and 14 are drawings for illustrating a method for identifying contamination of a protective window according to the rotation rate of a turntable according to at least one embodiment of the present disclosure.

[0025] The various embodiments of the present disclosure and the terms used therein are not intended to limit the technical features described in the present disclosure to specific embodiments, and should be understood to include various modifications, equivalents, or substitutions of said embodiments.

[0026] In relation to the description of the drawings, similar reference numerals may be used for similar or related components.

[0027] The singular form of the noun corresponding to an item may include one or plural items, unless the relevant context clearly indicates otherwise.

[0028] In the present disclosure, each of the phrases such as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B or C,” “at least one of A, B and C,” and “at least one of A, B, or C” may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof. For example, “A or B,” “at least one of A and B,” or “at least one of A or B” may refer to cases including (1) at least one A, (2) at least one B, or (3) both at least one A and at least one B.

[0029] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish a component from another component and do not limit the components in other aspects (e.g., importance or order).

[0030] Where any (e.g., 1st) component is referred to as "coupled" or "connected" to another (e.g., 2nd) component, with or without the terms "functionally" or "communicationly," it means that the component may be connected to the other component directly (e.g., via a wire), wirelessly, or through a third component.

[0031] Terms such as "include" or "have" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in this document, and do not preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0032] When it is said that a component is "connected," "combined," "supported," or "in contact" with another component, this includes not only cases where the components are directly connected, combined, supported, or in contact, but also cases where they are indirectly connected, combined, supported, or in contact through a third component.

[0033] When it is said that a component is located "on" another component, this includes not only cases where one component is in contact with the other, but also cases where another component exists between the two components.

[0034]

[0035] The term "and / or" includes a combination of multiple related described components or any of the multiple related described components.

[0036] In some situations, the expression “device configured to do something” may mean that the device is “capable of doing something” in conjunction with other devices or components. For example, the phrase “processor configured (or set) to perform A, B, and C” may mean a dedicated processor for performing the said operations (e.g., an embedded processor), or a generic-purpose processor (e.g., a CPU or application processor) capable of performing said operations by executing one or more software programs stored in a memory device.

[0037] In the embodiments, a "module" or "part" performs at least one function or operation and may be implemented in hardware or software, or a combination of hardware and software. Additionally, a plurality of "modules" or a plurality of "parts" may be integrated into at least one module and implemented by at least one processor (not shown), except for a "module" or "part" that needs to be implemented in specific hardware.

[0038] Meanwhile, the various elements and areas in the drawings are depicted schematically. Accordingly, the technical concept of the present invention is not limited by the relative sizes or spacing depicted in the attached drawings.

[0039] An embodiment of the present disclosure will be described in more detail below with reference to the attached drawings.

[0040] FIG. 1 is a drawing for explaining the operation of a cooking device according to an embodiment of the present disclosure.

[0041] In the present disclosure, the cooking device (100) refers to a device capable of heating food by irradiating it with microwaves. For example, the cooking device (100) may be a device such as a microwave oven or a microwave oven, but is not limited to a specific type. In the following description, the cooking device (100) is described on the premise that it is a microwave oven.

[0042] According to FIG. 1, (100) may include a thermal imaging camera (110). The thermal imaging camera (110) can photograph the cooking chamber (10) of the cooking device (100). For example, the thermal imaging camera (110) may be located inside a housing. The housing and the cooking chamber may be separated by a perforated metal plate. The lens of the thermal imaging camera (110) can photograph the cooking chamber through the perforation. Additionally, the shooting direction of the thermal imaging camera (110) may be downward (e.g., from the top of the cooking chamber (10) toward the bottom of the cooking chamber (10) where the turntable (150) is located). Accordingly, the thermal imaging camera (110) can photograph the turntable (150) and the surrounding area of ​​the turntable (150).

[0043] When a user input to operate the cooking device (100) is received, the cooking device (100) can irradiate microwaves into the cooking chamber (10). Then, when the temperature of the thermal imaging camera (110) rises due to the microwaves, the cooking device (100) can obtain a thermal image by photographing the background area and the cooking chamber (10) using the thermal imaging camera (110).

[0044] Here, the background area may include the interior space of the cooking room (10) excluding the turntable (150). For example, the background area may refer to the area surrounding the turntable (150).

[0045] Meanwhile, as food inside the cooking chamber (10) is heated, the lens portion of the thermal imaging camera (110) may become contaminated or damaged. To prevent this, a transparent protective window (140) may be attached to the lens of the thermal imaging camera (110). The protective window (140) may be a component for protecting the lens of the thermal imaging camera (110). Specifically, the protective window (140) may be placed between the turntable (150) of the cooking chamber and the thermal imaging camera (110) to protect the thermal imaging camera (110) from food placed on the turntable (150). The protective window (140) may be treated with a special coating to protect the lens from heat. For example, the protective window (140) may be composed of a material such as germanium or silicon.

[0046] If the protective window (140) is contaminated, the contaminants may obscure the lens of the thermal imaging camera (110). If the contaminants obscure the lens of the thermal imaging camera (110), the thermal imaging camera (110) may not be able to accurately measure the temperature of the food present inside the cooking chamber (10). Accordingly, the cooking device (100) identifies whether the protective window (140) is contaminated based on the thermal image obtained using the thermal imaging camera (110), and

[0047] If the protective window (140) is identified as contaminated, the heating unit (120) can be controlled to stop heating the food. Specific details regarding this will be described later.

[0048] FIG. 2 is a block diagram illustrating a cooking apparatus according to an embodiment of the present disclosure.

[0049] According to FIG. 2, the cooking device (100) may include a thermal imaging camera (110), a heating unit (120), and at least one processor (130).

[0050] A thermal imaging camera (110) can acquire a thermal image. Specifically, the thermal imaging camera (110) can detect radiant heat emitted by an object and acquire a thermal image showing the intensity and distribution of the detected heat.

[0051] For example, one thermal imaging camera (110) may be placed at the top of the cooking device (100) (e.g., the center of the top). However, according to the embodiments of the present disclosure, there are no special limitations on the location and number of thermal imaging cameras (110).

[0052] The heating unit (120) can heat food. For example, the heating unit (120) can generate microwaves and emit the generated microwaves. Since the microwaves emitted from the heating unit (120) have a very short wavelength, they can interact with water molecules inside the food and cause the water molecules to vibrate, and the vibration of the water molecules can be converted into heat to raise the temperature of the food. The location and number of heating units (120) can be determined in various ways. In addition, the heating unit (120) may include a microwave radiation unit.

[0053] At least one processor (130) can control the overall operation of the cooking device (100). Specifically, at least one processor (130) can control the overall operation of the cooking device (100) by being connected to each component of the cooking device (100). For example, at least one processor (130) can control the operation of the cooking device (100) by being electrically connected to a thermal imaging camera (110) and a heating unit (120). At least one processor (130) may include one or more of a CPU (Central Processing Unit), GPU (Graphics Processing Unit), APU (Accelerated Processing Unit), MIC (Many Integrated Core), DSP (Digital Signal Processor), NPU (Neural Processing Unit), hardware accelerator, or machine learning accelerator. At least one processor (130) can control one or any combination of other components of the cooking device (100) and can perform operations or data processing related to communication. At least one processor (130) can execute one or more programs or instructions stored in the memory (e.g., 170 in FIG. 3) of the cooking appliance (100). For example, at least one processor (130) can perform a method according to one embodiment of the present disclosure by executing one or more instructions stored in the memory (170).

[0054] When a method according to one embodiment of the present disclosure includes a plurality of operations, the plurality of operations may be performed by a single processor or by a plurality of processors. For example, when a first operation, a second operation, and a third operation are performed by a method according to one embodiment, the first operation, the second operation, and the third operation may all be performed by a first processor, or the first operation and the second operation may be performed by a first processor (e.g., a general-purpose processor) and the third operation may be performed by a second processor (e.g., an artificial intelligence dedicated processor).

[0055] At least one processor (130) may be implemented as a single-core processor including one core, or as one or more multi-core processors including multiple cores (e.g., homogeneous multi-core or heterogeneous multi-core). When at least one processor (130) is implemented as a multi-core processor, each of the multiple cores included in the multi-core processor may include internal processor memory such as cache memory or on-chip memory, and a common cache shared by multiple cores may be included in the multi-core processor. Additionally, each of the multiple cores included in the multi-core processor (or some of the multiple cores) may independently read and execute program instructions for implementing a method according to one embodiment of the present disclosure, or all (or some) of the multiple cores may be linked together to read and execute program instructions for implementing a method according to one embodiment of the present disclosure.

[0056] When a method according to one embodiment of the present disclosure includes a plurality of operations, the plurality of operations may be performed by one of the plurality of cores included in a multi-core processor, or may be performed by a plurality of cores. For example, when a first operation, a second operation, and a third operation are performed by a method according to one embodiment, the first operation, the second operation, and the third operation may all be performed by a first core included in a multi-core processor, or the first operation and the second operation may be performed by a first core included in a multi-core processor and the third operation may be performed by a second core included in a multi-core processor.

[0057] In the embodiments of the present disclosure, a processor may refer to a system-on-chip (SoC) in which one or more processors and other electronic components are integrated, a single-core processor, a multi-core processor, or a core included in a single-core processor or a multi-core processor, wherein the core may be implemented as a CPU, GPU, APU, MIC, DSP, NPU, hardware accelerator, or machine learning accelerator, but the embodiments of the present disclosure are not limited thereto. In the following description, at least one processor (130) is described as a processor (130).

[0058] FIG. 3 is a block diagram illustrating the detailed configuration of a cooking apparatus according to an embodiment of the present disclosure.

[0059] Referring to FIG. 3, the cooking device (100) may include a thermal imaging camera (110), a heating unit (120), at least one processor (130), a turntable (150), an interface (160), a memory (170), and a driving unit (180). However, such a configuration is exemplary, and it is understood that in carrying out the present disclosure, new configurations may be added or some configurations may be omitted in addition to such configurations. Meanwhile, detailed descriptions of configurations shown in FIG. 3 that overlap with configurations shown in FIG. 2 will be omitted.

[0060] The turntable (150) refers to a rotatable configuration. Specifically, the turntable (150) is placed at the bottom of the cooking appliance (100), and food or a container containing food (e.g., a plate) may be placed on the turntable (150). When the turntable (150) is rotated by the drive unit (180), the food placed on the turntable (150) may be rotated accordingly. The term turntable (150) may be replaced with terms such as, for example, a rotating plate.

[0061] When microwaves are emitted from the heating unit (120), if there is no turntable (150), certain parts of the food (e.g., the center) may be heated relatively quickly, while other parts (e.g., the periphery) may be heated relatively slowly. However, when the turntable (150) rotates, the food rotates along with it, so the food can be heated uniformly, and accordingly, the cooking result can be improved and the cooking time can also be shortened.

[0062] An interface (160) is a configuration created to interact between two or more systems, devices, programs, or users. The interface (160) may include at least one of a communication interface (161) and an input / output interface (162, 163).

[0063] The communication interface (161) includes a circuitry and can communicate with an external device (e.g., a server device and / or an external device). At least one processor (130) can receive various data or information from an external device connected through the communication interface (161) and can transmit various data or information to the external device.

[0064] The communication interface (161) can communicate with an external device through a nearby access point (AP). The access point (AP) can connect the local network (LAN) to which the cooking appliance (100) is connected to a wide area network (WAN) to which the external device is connected. The cooking appliance (100) can be connected to the external device through the network (WAN). Additionally, the communication interface (161) can perform device-to-device (D2D) communication with the external device. For example, the communication interface (161) can communicate with the external device over short distances without using an access point.

[0065] The communication interface (161) can communicate with an external device using various types of communication methods. For example, the communication interface (161) may include a LAN communication module such as an Ethernet module. The communication interface (161) may include wireless communication modules such as Wi-Fi, Wi-Fi Direct, Bluetooth, BLE (Bluetooth Low Energy), Zigbee, NFC, Z-Wave, and infrared communication. The communication interface (160) may include cellular communication modules such as 3G (3rd Generation), 3GPP (3rd Generation Partnership Project), LTE (Long Term Evolution), and 5G. The communication interface (161) may include communication modules such as HDMI (High-Definition Multimedia Interface) and USB (Universal Serial Bus).

[0066] The input interface (162) may include a circuit. The input interface (162) may receive user input for controlling the operation of the cooking appliance (100) and provide the user input to at least one processor (130). The user input may include an input for turning the heating unit (120) of the cooking appliance (100) on / off, an input for adjusting the intensity of the output power of the heating unit (120), an input for setting a timer, etc. The input interface may include, for example, a tact switch, a push switch, a slide switch, a toggle switch, a micro switch, a touch switch, a touch pad, a touch screen, a jog dial, and / or a microphone, etc.

[0067] The input interface (162) may be provided in an area of ​​the outer wall surface of the cooking appliance (100). For example, the input interface (162) may be provided in an area of ​​the front portion of the housing. However, the present disclosure is not limited thereto, and the input interface (162) may be provided in various locations, such as the front and / or side of the housing.

[0068] The output interface (163) includes a circuit, and at least one processor (130) can visually or audibly convey various information related to the cooking appliance (100) to the user through the output interface (163). The output interface (163) may include a Liquid Crystal Display (LCD) panel, a Light Emitting Diode (LED) panel, a speaker, etc.

[0069] The memory (170) may store at least one instruction regarding the cooking device (100). Additionally, the memory (170) may store an operating system (O / S) for operating the cooking device (100). Furthermore, the memory (170) may store various software programs or applications for operating the cooking device (100) according to various embodiments of the present disclosure. Additionally, the memory (170) may include semiconductor memory such as flash memory or magnetic storage media such as a hard disk.

[0070] Specifically, various software modules for operating a cooking appliance (100) according to various embodiments of the present disclosure may be stored in the memory (170), and the processor (130) may control the operation of the cooking appliance (100) by executing the various software modules stored in the memory (170). That is, the memory (170) is accessed by the processor (130), and data recording, modification, deletion, updating, etc. by the processor (130) may be performed.

[0071] Meanwhile, in the present disclosure, the term memory (170) may be used to include memory (170), ROM, RAM, or a memory card (e.g., micro SD card, memory stick) mounted in the processor (130).

[0072] In addition, various information necessary within the scope of achieving the purpose of the present disclosure may be stored in the memory (170), and the information stored in the memory (170) may be updated as it is received from an external device or input by a user.

[0073] In the present disclosure, information of a cooking device (100) may be stored in the memory (170). The information of the cooking device (100) may include information such as the type of the cooking device (100), whether a turntable exists, the size and height of the chamber, etc.

[0074] The drive unit (180) can rotate the turntable (150). Specifically, the drive unit (180) may include a motor that generates power to rotate the turntable (150) using electrical energy. Additionally, the drive unit (180) may further include components such as a drive camp and a bearing for transmitting the power generated by the motor, and a roller for smooth rotational movement of the turntable (150).

[0075] The processor (130) can control the drive unit (180) to rotate the turntable (150) while cooking of the food is performed by the heating unit (120).

[0076] Specifically, when user input is received to select cooking conditions and start cooking, the processor (130) can rotate the turntable (150) using the drive unit (180) while cooking is being performed so that the food is heated according to the selected conditions. For example, the selected conditions may be a set temperature (e.g., 80 degrees), a cooking time (e.g., 3 minutes), a cooking type (e.g., grilling), etc.

[0077] FIG. 4 is a flowchart illustrating a method for controlling a cooking appliance according to at least one embodiment of the present disclosure. When instructions are executed individually or collectively, the processor (130) can perform the operations of FIG. 4.

[0078] In operation 410, when the cooking device (100) is turned on, the processor (130) can rotate the turntable (150) and heat the food using the heating unit (120).

[0079] Specifically, the user can turn on the cooking device (100) through the input interface (162). When a command to turn on the cooking device (100) is input, the processor (130) can rotate the turntable (150) and control the heating unit (120) so that the cooking device (100) can generate microwaves to vibrate water molecules inside the food.

[0080] As the specific method of heating food by the processor (130) has been described later through FIGS. 2 and FIGS. 3, a redundant description is omitted.

[0081] In operation 420, the processor (130) can acquire a plurality of thermal images using a thermal imaging camera (110) while the turntable is rotating.

[0082] FIG. 4 is described on the premise that the turntable rotates one or more times. An embodiment in which the turntable rotates one or fewer times will be described later.

[0083] Specifically, the processor (130) can take a picture through the thermal imaging camera (110) when the cooking device (100) is turned on, and obtain a plurality of thermal images.

[0084] A thermal image consists of multiple pixels, and each pixel may contain information regarding temperature. For example, a thermal image may contain approximately 5,000 pixels, and pixels with higher temperatures may be represented in darker colors, while pixels with lower temperatures may be represented in brighter colors. However, the resolution and color representation method of the thermal image can be determined in various ways. For example, a thermal image may be represented as a two-dimensional array containing information regarding temperature values ​​for each pixel. When a thermal image is represented as a two-dimensional array, each coordinate of the thermal image can represent an accurate temperature value.

[0085] As described above, the thermal imaging camera (110) can photograph the lower part of the cooking chamber (10) from the upper part of the cooking chamber (10). Accordingly, when no object is placed on the turntable (150), the thermal image may include the turntable (150) and a background area. Additionally, when an object is placed on the turntable (150), the thermal image may include the turntable (150), a background area, and an object placed on the turntable (150) (e.g., food, etc.).

[0086] Additionally, the processor (130) can acquire multiple thermal images based on the shooting speed of the thermal imaging camera (110) and the time it takes for the turntable (150) to rotate one full turn.

[0087] Specifically, the processor (130) can acquire thermal images equal to the number of thermal images that the thermal camera (110) can acquire per hour multiplied by the time it takes for the turntable (150) to rotate one full turn.

[0088] For example, the thermal imaging camera (110) can take 7 to 10 shots per second. Additionally, the turntable (150) can rotate once every 20 seconds. In this case, the processor (130) can acquire 140 to 200 thermal images while the turntable rotates once.

[0089] The number of thermal images that the thermal imaging camera (110) can acquire per second and the time it takes for the turntable (150) to rotate one full turn are not limited to the examples described above and may have various values.

[0090] In operation 430, the processor (130) can identify a plurality of heating zones corresponding to food placed on the turntable (150) in a plurality of thermal images.

[0091] The heating area may be the area occupied by a moisture-containing object placed on a turntable in a thermal image. For example, the heating area may be the area where food is placed.

[0092] The processor (130) can identify the turntable area and the background area outside the turntable area in each of the plurality of thermal images.

[0093] The processor (130) can identify the average temperature of a preset area among the background areas outside the turntable (150) based on a preset area among the background areas outside the turntable (150) included in the thermal image. The preset area among the background areas outside the turntable (150) may be stored in memory (170).

[0094] Specifically, FIG. 5 is a drawing for explaining a method for identifying a heating area of ​​a cooking chamber according to at least one embodiment of the present disclosure.

[0095] Referring to FIG. 5, the thermal image may show the turntable (150) of the cooking room and the background area. At this time, one area within the background area may be pre-set. The pre-set area within the background area is defined as the first area (1).

[0096] The processor (130) can identify the average temperature of the first area (1). Specifically, the processor (130) can detect thermal radiation of food using a thermal imaging camera and acquire a thermal image. At this time, each pixel of the thermal image may contain temperature information of the actual cooking room corresponding to the pixel location.

[0097] The processor (130) can extract the temperature value of each pixel from the acquired thermal image. Based on the temperature value of each extracted pixel, the processor (150) can set a specific area to calculate the average temperature and identify the average temperature.

[0098] For example, the processor (130) can identify the average temperature of the pixels included in the first region (1). The average temperature of the pixels included in the first region (1) identified by the processor (130) can be considered as the temperature of the background region.

[0099] The processor (130) can identify at least one pixel among the pixels included in the turntable area in each of the plurality of thermal images that has a temperature difference from the background area greater than or equal to a preset value, and can identify the area including the at least one pixel in the plurality of thermal images as the plurality of heating areas.

[0100] That is, the processor (130) can identify that the pixels included in the preset turntable area constitute a heating area based on the difference between the temperature of the pixels included in the preset turntable area and the average temperature of the preset area among the background areas outside the turntable being greater than or equal to a preset value. The preset turntable area may be stored in memory (170).

[0101] Specifically, the preset turntable area (2) may be an area where the turntable (150) is presumed to be located. The processor (130) can identify pixels where the difference between the temperature of a pixel included in the preset turntable area (2) and the average temperature of a pixel included in the first area (1) is greater than or equal to a preset value. The processor (130) can identify the area occupied by the identified plurality of pixels among the pixels included in the preset turntable area (2) as a heating area.

[0102] In operation 440, the processor (130) can identify a cumulative heating area corresponding to a plurality of heating areas in a cumulative thermal image obtained by accumulating a plurality of thermal images.

[0103] The accumulated thermal image may be a thermal image captured by a thermal camera (110) while the turntable (150) rotates one full turn. Additionally, the accumulated heating area may be a heating area identified in the accumulated thermal image.

[0104] The processor (130) can acquire a plurality of thermal images while the turntable (150) rotates one full turn. Additionally, the processor (130) can binarize the plurality of thermal images. Specifically, the processor (130) can identify the area identified as a heating area among the plurality of thermal images as 1, and the area outside the heating area as 0. In the thermal images, 1 can be represented in white, and 0 can be represented in black.

[0105] Therefore, the processor (130) can convert the heating area to white and the area outside the heating area to black.

[0106] The processor (130) can accumulate multiple binarized images to obtain an accumulated thermal image.

[0107] Specifically, the processor (130) can identify pixel areas marked in white in a plurality of thermal images acquired while the turntable is rotating. The processor (130) can identify pixel areas marked in white at least once in the plurality of thermal images and mark the pixel areas marked in white at least once identified in the accumulated thermal images as white.

[0108] The processor (130) can obtain a cumulative thermal image by accumulating a plurality of binarized images such that for pixels at the same location in a plurality of binarized images, if at least one pixel among the pixels is a white pixel, the pixel corresponding to the location of the white pixel in the cumulative thermal image becomes a white pixel, and if the pixels are black pixels, the pixel corresponding to the location of the black pixel in the cumulative thermal image becomes a black pixel.

[0109] In the method described above, the processor (130) can identify an area containing white pixels among a plurality of pixels of an accumulated thermal image as an accumulated heating area.

[0110] FIGS. 6 and 7 are drawings showing thermal images of a cooking chamber according to at least one embodiment of the present disclosure. Referring to FIG. 6, the heating area may be an object containing moisture placed on a turntable as described above. For example, the heating area may be food.

[0111] In the cumulative thermal image acquired by rotating the turntable one full turn, the heating area may be displayed as a circle as shown in FIG. 7. On the other hand, if the window protecting the lens of the thermal imaging camera (110) is contaminated, the heating area in the cumulative thermal image acquired by rotating the turntable one full turn may not be displayed as a circle as shown in FIG. 8. Therefore, the processor (130) can identify whether the window is contaminated by identifying whether the heating area in the cumulative thermal image appears as a circle. The method by which the processor (130) identifies whether the heating area in the cumulative thermal image appears as a circle is explained based on operations 450 to 460.

[0112] In operation 450, the processor (130) can generate a circle based on the coordinate values ​​of a plurality of pixels selected from the outline of the accumulated heating area in the accumulated thermal image.

[0113] Specifically, the processor (130) can binarize the accumulated thermal image to distinguish between two types of pixels: pixels included in the heating area and pixels included in the area outside the heating area.

[0114] For example, the processor (130) can convert pixels included in the heating area to white and pixels included in the area outside the heating area to black. The method of binarizing the image is the same as described above.

[0115] The processor (130) can identify pixels adjacent to a black pixel among a plurality of white pixels included in the accumulated heating area as the outline of the accumulated heating area.

[0116] Specifically, the processor (130) can identify the colors of pixels adjacent to a pixel included in the heating area. As previously mentioned, the pixel included in the heating area may be white. Additionally, the pixel included in the area not included in the heating area may be black.

[0117] The outline of the heating area may be the boundary between the heating area and the area outside the heating area. Therefore, white pixels included in the outline of the heating area may be adjacent to black pixels included in the area outside the heating area.

[0118] The processor (130) can identify whether a pixel adjacent to a pixel included in the heating area is black. If a pixel adjacent to a pixel included in the heating area is black, the processor (130) can identify the pixel included in the heating area as a pixel included in the outline of the heating area. The processor (130) can identify pixels included in the outline of the heating area by identifying the color of a pixel adjacent to a pixel included in the heating area for the entire heating area of ​​the accumulated thermal image. The method by which the processor (130) distinguishes between pixels included in the heating area and pixels included in the area outside the heating area into two types is not limited to this and may be distinguished in various ways.

[0119] Additionally, the processor (130) can identify the coordinates of pixels included in the outline of the heating area in the cumulative thermal image. The origin of the coordinates may be pre-set. For example, the origin of the coordinates may be the top-left corner of the cumulative thermal image. However, the origin of the coordinates is not limited to this and may exist at various locations.

[0120] The processor (130) can generate multiple circles based on at least three pixels among the pixels corresponding to the outline of the accumulated heating area.

[0121] Specifically, the processor (130) can generate a circle based on extracting at least three coordinates from among the pixels included in the outline of the heating area. The processor (130) can randomly extract at least three coordinates from among the pixels included in the outline of the heating area. The processor (130) can generate a circle based on the equation of a circle with the point where the perpendicular bisectors of the three sides of the triangle formed by the three coordinates meet.

[0122] In operation 460, the processor (130) can identify whether the protective window is contaminated based on the generated circle.

[0123] Specifically, the processor (130) can identify the shape of the accumulated heating area based on the radius of the generated circle and the distance to the pixel included in the accumulated heating, and identify whether the window is contaminated.

[0124] To identify the shape of the accumulated heating area, the processor (130) can identify the number of pixels for which the difference between the radius of the generated circle and the distance from the center of the generated circle to the pixels included in the outline of the heating area is less than a preset value.

[0125] Specifically, the processor (130) can generate a circle and identify the radius (r) of the generated circle and the distance (d) to any pixel included in the outline of the heating area.

[0126] The processor (130) can identify the difference between r and d. Additionally, the processor (130) can identify the number of pixels where the difference between r and d is less than or equal to a preset value. Specifically, the processor (130) can repeat the operation of calculating the difference between r and d for all pixels included in the outline.

[0127] The processor (130) can identify, for each of the generated multiple circles, the ratio of specific pixels to pixels corresponding to the outline of the accumulated heating area. The specific pixels may include pixels in which the difference between r and d is less than a preset value.

[0128] Specifically, the processor (130) can identify the distance between the pixels corresponding to the outline of the accumulated heating area and the center pixels of the generated circle for each of the generated circles. Additionally, the processor (130) can identify the number of specific pixels among the pixels corresponding to the outline of the accumulated heating area such that the difference between the center pixel of the generated circle and the radius of the generated circle is less than a preset value.

[0129] The processor (130) can repeatedly perform the operation of identifying the number of specific pixels for each of the generated multiple circles.

[0130] Additionally, the processor (130) can identify the circle with the highest ratio of a specific pixel among the coordinates of all pixels forming the outline among a plurality of circles.

[0131] Specifically, the processor (130) can identify the circle with the largest number of pixels for which the difference between the radius (r) of the generated circle and the distance (d) from the center of the generated circle to the pixels included in the outer edge of the heating area is less than a preset value.

[0132] Additionally, the processor (130) can calculate the difference between r and d for each pixel forming the outline in the identified circle. The processor (130) can add up all the difference values ​​between r and d for each pixel. If the sum of the difference values ​​between r and d is greater than or equal to a preset value, the processor (130) can identify the accumulated heating area as not being a circle.

[0133] On the other hand, the processor (130) can identify that the accumulated heating area is close to a circle if the sum of the differences between r and d is less than a preset value.

[0134] In the method described above, the processor (130) can identify that the protective window (140) is not contaminated if the accumulated heating area is a circle. On the other hand, the processor (130) can identify that the protective window (140) is contaminated if the accumulated heating area is not a circle.

[0135] The processor (130) can control the heating unit to stop heating the cooking chamber (10) if it is identified that the protective window (140) is contaminated. Additionally, if the processor (130) identifies that the window is contaminated, it can send a notification to an external device stating that the window is contaminated and needs to be cleaned.

[0136] While the turntable (150) is rotating, objects inside the cooking chamber (10) may be heated unevenly. If objects are heated unevenly, a temperature difference may occur between pixels included in the heating area.

[0137] The processor (130) can identify that the accumulated heating image is not a circle even though the shape of the image is a circle, when a temperature difference occurs between pixels included in the heating area.

[0138] To prevent this, if the processor (130) identifies that the shape of the accumulated heating image is not a circle, it may stop the operation of the heating unit (130) for a preset time to convect the temperature. After the preset time, the processor (130) may operate the heating unit (130) again and identify the shape of the accumulated heating image. At this time, if the accumulated heating image is a circle, the processor (130) may identify that the protective window (130) is not contaminated. On the other hand, if the accumulated heating image is not a circle, the processor (130) may identify that the protective window (130) is contaminated.

[0139] In addition to the method described above, the processor (130) can identify whether the window is contaminated based on identifying the contour of the heating area in the thermal image.

[0140] If the protective window (140) is contaminated during the operation of the cooking device (100), the boundary of the heating area may be obscured in the thermal image. In this case, the processor (130) can identify the temperature of the obscured part of the heating area as lower than the actual temperature. That is, the brightness of the pixels included in the obscured part of the heating area in the thermal image may differ little from the brightness of the pixels included in the background area. Therefore, the processor (130) can identify whether the window (140) is contaminated based on the change in brightness of the pixels included in the heating area. A specific method for this is explained based on FIG. 9.

[0141] FIG. 9 is a flowchart illustrating a method for identifying contamination of a protective window that occurs during the operation of a cooking appliance according to at least one embodiment of the present disclosure.

[0142] In operation 910, the processor (130) can identify a heating area inside the cooking chamber (10). The method by which the processor (130) identifies a heating area inside the cooking chamber (10) is as described above.

[0143] In operation 920, the processor (130) can identify the contour of the heating area.

[0144] Specifically, the processor (130) can obtain high frequency information from the thermal image. The high frequency information may include information about rapidly changing configurations in the image. For example, the high frequency information may include information about lines where two objects meet. Thus, by extracting high frequency information from the thermal image, the processor (130) can identify the boundary between the heating area and the background. Additionally, the high frequency information may have a large value when the brightness of the pixels changes significantly. On the other hand, the high frequency information may have a small value when the brightness of the pixels changes little.

[0145] The processor (130) can obtain high-frequency information of a thermal image using a Laplacian operator or a Sobel filter.

[0146] The Laplacian operator is a second-order differential operator used in image processing. The processor (130) can use the Laplacian operator to identify abrupt changes in brightness around each pixel of an image.

[0147] Specifically, the processor (130) may use a matrix when using a Laplacian operator on a thermal image. The matrix is ​​called a mask, and a 5x5 matrix may be used, but is not limited thereto, and masks of various sizes may be used.

[0148] Each pixel included in the thermal image can have a value corresponding to brightness. Therefore, the processor (130) can apply a mask to each pixel of the thermal image to perform a convolution operation and identify the difference in brightness with surrounding pixels.

[0149] Specifically, the processor (130) can apply a mask over a thermal image with the pixel at which brightness difference is to be identified as the center. Additionally, the processor (130) can add the product of each coordinate of the mask and the pixel value of the pixel located at each coordinate of the mask. If the result of the convolution is greater than a preset value, the pixel located at the center of the mask can be identified as a pixel included in the boundary of the image. On the other hand, if the result of the convolution is smaller than a preset value, the pixel located at the center of the mask can be identified as not being a pixel included in the boundary of the image.

[0150] Additionally, the processor (130) can identify the boundaries of the heating area using a Sobel filter. The Sobel filter is a filter that detects boundaries by calculating brightness changes in the horizontal and vertical directions of the image.

[0151] The processor (130) can identify abrupt changes in brightness around each pixel of an image using a Sobel filter. Unlike the Laplacian operator, which uses only one mask, the Sobel filter can use a mask in the horizontal direction (x-axis) and a mask in the vertical direction (y-axis).

[0152] Specifically, the processor (130) can apply a mask over a thermal image with the pixel to be identified as the center. The processor (130) can square the convolution value obtained through the horizontal mask and the convolution value obtained through the vertical mask, add them together, and then take the square root. If the size of the square root value obtained by the processor (130) is greater than a preset value, the pixel located at the center of the mask can be identified as a pixel included in the boundary of the image. On the other hand, if the size of the square root value is smaller than a preset value, the pixel located at the center of the mask can be identified as not being a pixel included in the boundary of the image.

[0153] The processor (130) can identify the boundary portion of the heating area within the thermal image through the aforementioned process.

[0154] In operation 930, the processor (130) can compare the acquired thermal images in chronological order to identify the amount of change in high-frequency information and the amount of change in temperature of the pixels forming the contour of the object.

[0155] Specifically, the processor (130) can compare the high-frequency information values ​​of the thermal image acquired at time t and the thermal image acquired at time t+1 after the turntable has rotated. The processor (130) can obtain the sum of all high-frequency information values ​​of each pixel located at the boundary of the heating area of ​​the thermal image acquired at time t. Additionally, the processor (130) can obtain the sum of all high-frequency information values ​​of each pixel located at the boundary of the heating area of ​​the thermal image acquired at time t+1.

[0156] In operation 940-Y, the processor (130) can identify that the protective window (140) is contaminated if the difference between the sum of the high-frequency information values ​​obtained at time t and the sum of the high-frequency information values ​​obtained at time t+1 is greater than or equal to a preset value (operation 950). On the other hand, in operation 940-N, the processor (130) can identify that the protective window (140) is not contaminated if the difference between the sum of the high-frequency information values ​​obtained at time t and the sum of the high-frequency information values ​​obtained at time t+1 is less than a preset value (operation 960).

[0157] Additionally, the processor (130) may identify whether the protective window (140) is contaminated based on the difference between the temperature average of the entire thermal image acquired at time t and the temperature average of the entire thermal image acquired at time t+1.

[0158] In operation 940-Y, the processor (130) can identify that the protective window (140) is contaminated if the difference between the sum of the high-frequency information values ​​acquired at time t and the sum of the high-frequency information values ​​acquired at time t+1 is greater than or equal to a preset value, and the difference between the temperature average of the entire thermal image acquired at time t and the temperature average of the entire thermal image acquired at time t+1 is also greater than or equal to a preset value (operation 950).

[0159] On the other hand, in operation 940-N, the processor (130) can identify that the protective window (140) is not contaminated if the difference between the sum of the high-frequency information values ​​acquired at time t and the sum of the high-frequency information values ​​acquired at time t+1 is less than a preset value, and the difference between the temperature average of the entire thermal image acquired at time t and the temperature average of the entire thermal image acquired at time t+1 is also less than a preset value (operation 960).

[0160] According to the method described above, the processor (130) can identify cases where the protective window (140) is contaminated during the operation of the cooking device (100).

[0161] In addition to the method described above, the processor (130) can identify whether the window is contaminated based on the average temperature of the concentric circles formed by the pixels of the heating area in the thermal image while the turntable (150) rotates one full turn. A specific method for this is described based on FIG. 10.

[0162] FIG. 10 is a flowchart illustrating another embodiment for identifying contamination of a protective window according to at least one embodiment of the present disclosure.

[0163] In operation 1010, the processor (130) can identify a heating area inside the cooking chamber (10). The method by which the processor (130) identifies the heating area is as described above.

[0164] In operation 1020, the processor (130) can acquire multiple thermal images using a thermal imaging camera while the turntable (150) rotates one or more times. Additionally, the processor (130) can generate an image by accumulating multiple thermal images. A specific method for generating an accumulated thermal image has been described above.

[0165] When the turntable (150) rotates one full turn, each pixel included in the heating area can also rotate one full turn. Therefore, when the processor (150) generates a cumulative heating thermal image, each pixel included in the heating area can generate multiple concentric circles centered on the turntable (150). To do this, the processor (130) must identify the center position of the turntable (150).

[0166] In operation 1030, the processor (130) can identify the center of the turntable (150).

[0167] The center position of the turntable may be stored in memory (170), but there may be cases where the center position of the turntable needs to be re-identified according to the position of the thermal imaging camera (110).

[0168] Specifically, arbitrary coordinates that can be the center of the turntable (150) and a range of x-coordinates and y-coordinates that are estimated to be the center of the turntable (150) may be stored in memory (170).

[0169] For example, the coordinates that can be the center of the turntable (150) may be stored as (30,30). Additionally, the range of x-coordinates and y-coordinates that are estimated to be the center of the turntable (150) may each be -5 to +5. Thus, the x-coordinate may have a range from 25 to 35, and the y-coordinate may also have a range from 25 to 35.

[0170] The processor (130) can identify all possible coordinates based on the range of x and y coordinates.

[0171] In a plurality of circles centered on the turntable (150), a plurality of pixels included in one circle may be rotated while a specific point of food is fixed. Therefore, the temperature values ​​of the plurality of pixels included in one circle may not differ significantly.

[0172] For example, if the center coordinates of the turntable (150) are (30, 30), the difference in temperature between the pixel located at (40, 30) and the pixel located at (20, 30) may not be large.

[0173] Therefore, the processor (130) can identify the temperature difference between two pixels that are equidistant from each other for each of all possible coordinate cases. The processor (130) can identify the coordinate with the smallest temperature difference between the two pixels as the center coordinate of the turntable (150).

[0174] In operation 1040, the processor (130) can identify the average temperature of each of the multiple concentric circles generated while the turntable (150) rotates one full turn.

[0175] Specifically, the processor (130) can identify the temperature of the pixels included in each of the multiple concentric circles centered on the turntable (150). Accordingly, the processor (130) can identify the average temperature of the pixels included in each of the multiple concentric circles.

[0176] In operation 1050, the processor (130) can identify whether the difference between the average temperature of the pixels formed by each concentric circle and the temperature of the pixels included in each concentric circle is greater than or equal to a preset value.

[0177] Specifically, the processor (130) can identify the average temperature of the pixels included in each of the plurality of concentric circles and the temperature difference of the individual pixels included in each of the plurality of concentric circles.

[0178] Additionally, if there is a pixel where the identified temperature difference is greater than a preset value, the processor (130) can identify that the protective window (140) is contaminated and the thermal imaging camera (110) is mis-detecting the temperature of the object (operation 1060).

[0179] On the other hand, for pixels where the identified temperature difference is less than a preset value, the processor (130) can identify that the protective window (140) is not contaminated and the thermal imaging camera (110) detects the temperature of the object normally (operation 1070).

[0180] For example, assume that the average temperature of one of the multiple concentric circles is 50 degrees. In this case, among the pixels included in the concentric circle with an average temperature of 50 degrees, assume that the temperatures of some pixels are 51, 52, and 44 degrees, respectively, and that the preset values ​​are -3 degrees to +3 degrees.

[0181] Pixels detected at temperatures of 51 and 52 degrees, respectively, have a difference within the average temperature and a preset value. Therefore, the processor (130) can identify that for pixels detected at temperatures of 51 and 52 degrees, the protective window (140) is not contaminated and the thermal imaging camera (110) detects the temperature of the object normally.

[0182] On the other hand, for pixels where the temperature is detected as 44 degrees, there is a difference exceeding the average temperature and preset value. Therefore, the processor (130) can identify that for pixels where the temperature is detected as 44 degrees, the protective window (140) is contaminated and the thermal imaging camera (110) misdetects the temperature of the object.

[0183] In the example described above, the amount of computation can be massive because the processor (130) calculates the average temperature and the temperature difference between each pixel for each of the multiple concentric circles generated by multiple pixels.

[0184] The processor (130) can convert the accumulated thermal image into a polar coordinate system as shown in FIG. 11 to reduce the amount of computation. A polar coordinate system is a coordinate system that expresses the position of a point in terms of angles and distances. Thus, the x-axis of the polar coordinate system can be the radius and the y-axis can be the angle.

[0185] The processor (130) may assume that the object placed in the first acquired thermal image is 0 degrees. The processor (130) may generate a polar coordinate system based on the rotation angle of the object while the turntable (150) rotates one full turn and the distance from the center of the turntable (150) to the pixel.

[0186] The processor (130) can identify the difference between the average temperature for each radius and the temperature of individual pixels included in each radius, as in the example described above. Even in this case, if there is a pixel where the identified temperature difference is greater than or equal to a preset value, the processor (130) can identify that the protective window (140) is contaminated and the thermal imaging camera (110) is misdetecting the temperature of the object.

[0187] FIG. 12 is a drawing of the cumulative thermal image converted into polar coordinates when the protective window (140) is contaminated.

[0188] As described above, pixels included within the same radius may have similar temperatures. However, if the protective window (140) is contaminated, the thermal imaging camera (110) may not be able to properly detect the temperature of the object. Therefore, there may be a significant difference in temperature values ​​among pixels included within the same radius in the cumulative thermal image.

[0189] On the other hand, the processor (130) can identify that for pixels where the identified temperature difference is less than a preset value, the protective window (140) is not contaminated and the thermal imaging camera (110) detects the temperature of the object normally.

[0190] FIG. 11 is a drawing of the cumulative thermal image converted into polar coordinates when the protective window (140) is not contaminated.

[0191] Since pixels within the same radius may have similar temperatures, there may not be a significant difference in temperature values ​​among pixels within the same radius in a cumulative thermal image.

[0192] When the processor (130) converts the accumulated thermal image into a polar coordinate system, it may not be necessary to identify concentric circles and individual pixels included in the concentric circles as in the example above. Since the processor (130) only needs to identify whether the average value of the pixels included on the vertical axis of the graph and the difference value of the temperature of individual pixels are less than a preset value, the amount of computation of the processor (130) can be reduced compared to the example above.

[0193] Additionally, the processor (130) can identify whether the protective window (140) is contaminated based on statistics by radius.

[0194] Specifically, the processor (130) can identify that the protective window (140) is contaminated if the difference between the pixel detected with the largest temperature and the pixel detected with the smallest temperature among the pixels included in each radius is greater than or equal to a preset value.

[0195] To further reduce the computational load of the processor (130), the processor (130) can generate an accumulated thermal image by rotating the turntable (150) only partially, without rotating it a full turn. This is explained based on FIGS. 13 and 14.

[0196] FIGS. 13 and 14 are drawings for explaining a method of identifying contamination of a protective window (140) according to the rotation rate of a turntable according to at least one embodiment of the present disclosure.

[0197] For example, referring to FIG. 13, the processor (130) can generate a cumulative thermal image by rotating the turntable (150) halfway. Also, referring to FIG. 14, the processor (130) can generate a polar coordinate image based on the generated cumulative thermal image. Rotating the turntable (150) halfway means that the rotation angle is between 0 and 180 degrees. As previously mentioned, there may not be a significant difference in temperature among pixels included within the same radius. Therefore, for the same radius, the temperature from 180 to 360 degrees of the generated polar coordinate image may be similar to the temperature from 0 to 180 degrees.

[0198] Therefore, if a polar coordinate system is formed based on the fact that temperatures from 0 to 180 degrees are similar to temperatures from 180 degrees to 360 degrees, a polar coordinate system image can be obtained when the turntable (150) is rotated one full turn as in Fig. 11.

[0199] Therefore, the processor (130) can identify whether the protective window (140) is contaminated based on the acquired polar coordinate system image as described above.

[0200] Various embodiments of the present document may be implemented as software comprising one or more instructions stored in a storage medium (e.g., memory (170)) readable by a machine (e.g., cooking machine (100)). For example, a processor (e.g., processor (130)) of the machine (e.g., cooking machine (100)) may call at least one of the one or more instructions stored in the storage medium and execute it. This enables the machine to be operated to perform at least one function according to the at least one called instruction. The one or more instructions may include code generated by a compiler or code that can be executed by an interpreter. The storage medium readable by the machine may be provided in the form of a non-transitory storage medium. Here, 'non-temporary' simply means that the storage medium is a tangible device and does not contain a signal (e.g., electromagnetic waves), and the term does not distinguish between cases where data is stored semi-permanently and cases where it is stored temporarily.

[0201] According to one embodiment, the method according to the various embodiments disclosed herein may be provided by being included in a computer program product. The computer program product may be traded between a seller and a buyer as a product. The computer program product may be distributed in the form of a device-readable storage medium (e.g., compact disc read-only memory (CD-ROM)) or an application store (e.g., Play Store). ™It can be distributed online (e.g., downloaded or uploaded) through ) or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily created on a device-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or a relay server.

[0202] According to various embodiments, each component (e.g., module or program) of the components described above may include a singular or multiple entities, and some of the multiple entities may be separated and placed in other components. According to various embodiments, one or more of the components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Generally or additionally, multiple components (e.g., module or program) may be integrated into a single component. In this case, the integrated component may perform one or more functions of each of the multiple components in the same or similar manner as those performed by the corresponding component among the multiple components prior to integration. According to various embodiments, operations performed by the module, program, or other components may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0203] Although the present invention has been described above with reference to the attached drawings, the scope of the present invention is determined by the claims set forth below and should not be interpreted as being limited to the aforementioned embodiments and / or drawings. Furthermore, it should be clearly understood that improvements, changes, and modifications to the invention described in the claims that are obvious to those skilled in the art are also included within the scope of the present invention.

Claims

1. Regarding cooking appliances, Heating part; A thermal imaging camera positioned above the cooking chamber and for photographing the lower area of ​​the cooking chamber where the turntable is located; A window positioned between the turntable of the above-mentioned cooking room and the thermal imaging camera to protect the thermal imaging camera from food placed on the turntable; Memory for storing instructions; and at least one processor including processing circuitry; and The above at least one processor, when the instructions are executed individually or collectively, When the above cooking device is turned on, the above turntable is rotated, and the food is heated using the above heating unit, and While the above turntable rotates, a plurality of thermal images are acquired using the thermal imaging camera, and Identifying a plurality of heating zones, which are areas occupied by food placed on the turntable in the plurality of thermal images, and Identifying a cumulative heating area corresponding to the plurality of heating areas in a cumulative thermal image obtained by accumulating the plurality of thermal images, and A circle is generated based on the coordinate values ​​of a plurality of pixels selected from the outline of the accumulated heating area in the above accumulated thermal image, and A cooking device that identifies whether the window is contaminated based on the circle generated above.

2. In Paragraph 1, The above at least one processor, when the instructions are executed individually or collectively, Identifying the turntable area and the background area outside the turntable area in each of the plurality of thermal images, and Identifying at least one pixel among the pixels included in the turntable area in each of the plurality of thermal images above, wherein the temperature difference from the background area is greater than or equal to a preset value, and A cooking device that identifies an area including at least one pixel in the plurality of thermal images as the plurality of heating areas.

3. In Paragraph 1, The above at least one processor, when the instructions are executed individually or collectively, The above plurality of thermal images are binarized to obtain a plurality of binarized images composed of a first pixel and a second pixel, and The above plurality of binarized images are accumulated to obtain the accumulated thermal image, and A cooking device that identifies an area including the first pixel among a plurality of pixels of the above-mentioned cumulative thermal image as the above-mentioned cumulative heating area.

4. In Paragraph 3, The above at least one processor, when the instructions are executed individually or collectively, A cooking device that acquires a cumulative thermal image by accumulating a plurality of binarized images such that, for pixels at the same location in the plurality of binarized images, if at least one pixel among the pixels is the first pixel, the pixel at the location in the cumulative thermal image becomes the first pixel, and if the pixels are the second pixel, the pixel at the location in the cumulative thermal image becomes the second pixel.

5. In Paragraph 3, The above at least one processor, when the instructions are executed individually or collectively, A cooking device that identifies pixels adjacent to a second pixel among a plurality of first pixels included in the above-mentioned cumulative heating area as the outline of the above-mentioned cumulative heating area.

6. In Paragraph 1, The above at least one processor, when the instructions are executed individually or collectively, Based on the circle generated above, identify whether the accumulated heating area is a circle, and A cooking device that identifies whether the window is contaminated based on the cause of the above-mentioned cumulative heating area.

7. In Paragraph 6, The above at least one processor, when the instructions are executed individually or collectively, A plurality of circles are generated based on at least three pixels selected from among the pixels corresponding to the outline of the accumulated heating area, and For each of the plurality of circles generated above, the ratio of specific pixels to pixels corresponding to the outline of the accumulated heating area is identified, and Identify the circle with the largest identified ratio among the plurality of circles above, and In the above-identified circle, for each pixel forming the outline of the above-identified circle, the radius of the above-identified circle and the difference in distance from the center of the above-identified circle to the pixel included in the heating area are identified, and If the sum of the above distance differences is less than a preset value, the above accumulated heating area is identified as the cause, and if the above accumulated heating area is identified as the cause, the above window is identified as not contaminated. A cooking device that identifies the accumulated heating area as not being a circle if the sum of the above distance differences is greater than or equal to a preset value, and identifies the window as being contaminated if the accumulated heating area is identified as not being a circle.

8. In Paragraph 7, The above at least one processor, when the instructions are executed individually or collectively, For each of the plurality of circles generated above, the distance between the pixels corresponding to the outline of the accumulated heating area and the center pixels of the generated circle is identified, and A cooking device that identifies specific pixels among pixels corresponding to the outline of the accumulated heating area, wherein the distance from the center pixel of the generated circle is less than the difference between the radius of the generated circle and the specific pixels is less than a preset value.

9. In Paragraph 1, The above at least one processor, when the instructions are executed individually or collectively, A plurality of thermal images are acquired based on the shooting speed of the thermal imaging camera and the time it takes for the turntable to rotate one full revolution, and A cooking device that identifies the accumulated heating area by accumulating the thermal images acquired above.

10. In Paragraph 1, The above at least one processor, when the instructions are executed individually or collectively, A cooking device that controls the heating unit to stop heating the food when the window is identified as contaminated.

11. A method for controlling a cooking appliance including a heating unit, a turntable, a thermal imaging camera, and a window, A stage in which instructions are executed individually or collectively; When the above cooking device is turned on, a step of rotating the turntable and heating the food using the heating unit; A step of acquiring a plurality of thermal images using the thermal imaging camera while the turntable rotates one or more times; A step of identifying a plurality of heating zones corresponding to food placed on the turntable in the plurality of thermal images; A step of identifying a cumulative heating region corresponding to the plurality of heating regions in a cumulative thermal image obtained by accumulating the plurality of thermal images; A step of generating a circle based on the coordinate values ​​of a plurality of pixels selected from the outline of the accumulated heating area in the above accumulated thermal image; and A control method comprising the step of identifying whether the window is contaminated based on the generated circle.

12. In Paragraph 11, The step of identifying the plurality of heating zones above is, A step of identifying the turntable area and the background area outside the turntable area in each of the plurality of thermal images; A step of identifying at least one pixel among the pixels included in the turntable area in each of the plurality of thermal images, wherein the temperature difference from the background area is greater than or equal to a preset value; and A control method comprising the step of identifying a plurality of heating regions including a region comprising at least one pixel in the plurality of thermal images.

13. In Paragraph 11, The step of identifying the above-mentioned cumulative heating area is, A step of binarizing the plurality of thermal images to obtain a plurality of binarized images composed of a first pixel and a second pixel; A step of acquiring the accumulated thermal image by accumulating the plurality of binarized images; and A control method comprising the step of identifying an area including the first pixel among a plurality of pixels of the above-mentioned cumulative thermal image as the above-mentioned cumulative heating area.

14. In Paragraph 13, The step of acquiring the above-mentioned cumulative thermal image is, A control method comprising the step of accumulating a plurality of binarized images to obtain a cumulative thermal image, wherein for pixels at the same location in the plurality of binarized images, if at least one pixel among the pixels is a first pixel, the pixel at the location in the cumulative thermal image becomes a first pixel, and if the pixels are a second pixel, the pixel at the location in the cumulative thermal image becomes a second pixel.

15. In Paragraph 13, A control method further comprising the step of identifying pixels adjacent to a second pixel among a plurality of first pixels included in the cumulative heating area as the outline of the cumulative heating area.

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