Patent Description:
A microwave oven is a kitchen appliance that uses electromagnetic radiation to heat a food item placed within a cavity thereof. For example, a magnetron within the microwave oven can emit microwaves into the cavity. Water molecules of the food item within the microwave oven absorb the microwaves, which causes the water molecules to vibrate and generate heat. The generated heat conducts through the food item.

Some microwave ovens include an automatic heating function. With the automatic heating function, an infrared sensor of the microwave oven is utilized to determine a temperature of the food item being heated. In general, when the determined temperature of the food item reaches a desired temperature, the microwave oven ceases emitting microwaves.

Accuracy of the determination of the temperature of the food item is a function of position of the food relative to the infrared sensor. In short, the further the food item is from the infrared sensor, the less accurate the determination of the temperature of the food item from the output of the infrared sensor will be. A lack of uniform microwave energy distribution throughout a cavity in which the food item is placed for heating compounds the inaccuracy of the temperature determination.

<CIT> discloses a microwave oven and a method of operating the microwave oven according to the preambles of claims <NUM> and <NUM> respectively.

When the food item is at a temperature sufficiently different than the cavity of the microwave, the infrared sensor can be utilized to identify the position of the food item relative to the infrared sensor. Such instances include when the food item is frozen, or when the food item is warm but not as warm as desired, while the cavity is near room temperature. The temperature of the food item and the temperature of the cavity sufficiently contrast for the microwave oven to determine the position of the food item relative to the infrared sensor, before the heating operation begins. If the food item is determined to be too far from the infrared sensor for the microwave oven to determine accurately the temperature of the food item during the heating operation, then the microwave oven can prompt the user to reposition the food item to a position closer to the infrared sensor.

However, there is a problem in that, when the temperature of the food item and the temperature of the cavity are approximately the same, the microwave oven cannot utilize a contrast in the temperatures (as determined via output from the infrared sensor) to determine the position of the food item before the heating operation begins. The microwave oven would then first have to heat the food item to generate the temperature contrast with the cavity and then determine whether the food item had been properly placed within the cavity relative to the infrared sensor to allow for accurate automatic heating of the food item. If the microwave oven determines that the food item is inadequately placed within the cavity, then the microwave would have to stop the heating operation, notify the user, and wait for the user to replace the food item at a better position within the cavity. That may cause the user to be less than completely satisfied.

The present disclosure addresses that problem by (i) estimating where in the cavity of the microwave oven the user has placed the food item relative to an infrared sensor of the microwave oven, despite the temperature of the food item not contrasting with the temperature of the cavity, (ii) determining whether the food item is placed in a position within the cavity that allows the infrared sensor to provide output that is accurate enough to determine a temperature of the food item, and (iii) if it is determined that the user has not placed the food item in such a position, then notifying the user to replace the food item in such a position. As will be further elaborated upon herein, the microwave oven can estimate where in the cavity the user has placed the food item by recognizing, via output from the infrared sensor, a rise and fall in temperature at one or more positions within the cavity. The rise and fall in temperature is indicative of a hand of the user entering the cavity to place the food item therein and, then, leaving the cavity. Although the food item and the cavity may be at similar temperatures, the hand of the user is likely at a much higher temperature than the cavity. Thus, the output of the infrared sensor can be interpreted to determine the presence of the hand in the cavity and the assumed deposit of the food item within the cavity. The output of the infrared sensor can further be utilized to determine the positions of the hand within the cavity while the hand was delivering the food item into the cavity. From the determined positions of the hand, the microwave oven can estimate the position(s) of the food item within the cavity. The microwave oven can be installed with a taught algorithm that correlates sensed positions of the hand with the positions of the food item within the cavity that the hand deposited. If the microwave oven determines that the food item was suboptimally placed within the cavity relative to the position of the infrared sensor, then the microwave oven can prompt the user to replace the food item before commencing the heating operation. Or the microwave oven may move the food item automatically to a more optimal position. On the other hand, if the microwave oven determines that the food item was adequately placed within the cavity to permit automatic cooking of the food item, then the microwave oven commences the heating operation. Determining the position or positions of the food item before commencing the heating operation saves time and may improve user satisfaction with the microwave oven.

Other ways to estimate the position of the food item having a similar temperature as the cavity are additionally disclosed herein.

According to one aspect of the present disclosure, a microwave oven includes (a) a cavity configured to accept a food item for heating, the cavity providing an array of positions at which the food item can be placed; (b) an infrared sensor comprising an array of pixels, each pixel configured to generate an output and each pixel corresponding to a different position of the array of positions of the cavity; (c) a human-machine interface configured to provide an instruction to the user; and (d) a controller in communication with the infrared sensor and the human-machine interface, the controller configured: (i) to determine a temperature at each position of the array of positions of the cavity as a function of the output of each pixel of the array of pixels; (ii) to recognize a rise and fall in the temperature at one or more positions of the array of positions within the cavity; (iii) to estimate the position or positions of the array of positions within the cavity that a food item occupies as a function of the one or more positions of the array of positions within the cavity where the controller recognized a rise and fall in temperature occurred; and (iv) to determine whether the position or positions that the food item is estimated to occupy is adequate for the controller to determine accurately a temperature of the food item during an automatic heating operation that utilizes the infrared sensor.

According to another aspect of the present disclosure, a microwave oven comprises:
(a) a cabinet comprising a floor, a ceiling, and opposing sidewalls defining a cavity configured to accept a food item for heating and an opening into the cavity from an external environment; (b) one or more sensors positioned to generate output indicative of whether and where laterally an object enters the opening from the external environment into the cavity; (c) a human-machine interface configured to provide an instruction to the user; (d) an infrared sensor configured to determine a temperature of the food item during an automatic heating operation of the food item; and (e) a controller in communication with the one or more sensors and the human-machine interface, the controller configured: (i) to estimate a position or positions within the cavity that a food item occupies as a function of the output of the one or more sensors; and (ii) to determine whether the position or positions that the food item is estimated to occupy is adequate for the controller to determine accurately the temperature of the food item during the automatic heating operation.

According to yet another aspect of the present disclosure, a method of operating a microwave oven comprises: (i) estimating one or more positions within a cavity of a microwave oven that a food item occupies, without first heating the food item within the cavity; and (ii) determining that the one or more positions that the food item is estimated to occupy is suboptimal for the microwave oven to determine accurately, with an infrared sensor of the microwave oven, a temperature of the food item during an automatic heating operation of the food item.

The present illustrated embodiments reside primarily in combinations of method steps and apparatus components related to a microwave oven. Accordingly, the apparatus components and method steps have been represented, where appropriate, by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Further, like numerals in the description and drawings represent like elements.

Unless stated otherwise, the term "front" shall refer to the surface of the element closer to an intended viewer (e.g., a user of the microwave), and the term "rear" shall refer to the surface of the element further from the intended viewer.

The terms "including," "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by "comprises a. " does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprise the element.

Referring to <FIG>, a microwave oven <NUM> includes a cabinet <NUM> and a door <NUM> attached to the cabinet <NUM>. The cabinet <NUM> defines a cavity <NUM>. For example, the cabinet <NUM> can provide a floor <NUM> and a ceiling <NUM> opposing each other, a sidewall <NUM> and a sidewall <NUM> opposing each other, and a rear wall <NUM> that opposes the door <NUM> when the door <NUM> is in a closed position <NUM> (see <FIG>), which collectively define the cavity <NUM>. The cavity <NUM> has an opening <NUM>. The floor <NUM> has a perimeter <NUM> bound by the sidewalls <NUM>, <NUM>, the rear wall <NUM>, and the opening <NUM> into the cavity <NUM>. The cavity <NUM> is configured to accept a food item <NUM> for heating. For example, the cavity <NUM> is sized appropriately to accept the food item <NUM> therein, with sufficient distance between the floor <NUM> and the ceiling <NUM>, between the sidewalls <NUM>, <NUM>, and between the rear wall <NUM> and the door <NUM>. In the closed position <NUM>, the door <NUM> separates the cavity <NUM> from an external environment <NUM> and, thus, denies a user <NUM> access to the cavity <NUM> from the external environment <NUM>. The door <NUM> additionally has an open position <NUM> (see <FIG>), where the door <NUM> allows the user <NUM> access to the cavity <NUM> from the external environment <NUM>. In the closed position <NUM>, the door <NUM> covers the opening <NUM> into the cavity <NUM>. In the open position <NUM>, the door <NUM> does not cover the opening <NUM> into the cavity <NUM>. For example, a user <NUM> is able to place the food item <NUM> within the cavity <NUM>, when the door <NUM> is in the open position <NUM>.

The microwave oven <NUM> further includes a magnetron <NUM> and a waveguide <NUM>, or some other component to transfer the microwaves from the magnetron <NUM> to the cavity <NUM>. The magnetron <NUM> generates the microwaves that heat the food item <NUM>. The magnetron <NUM> generates the microwaves via a process called electron cyclotron resonance, where a magnetic field accelerates electrons in a circular path within a vacuum tube. As the electrons move in that circular path, the electrons emit in-phase microwaves having the same frequency. The waveguide <NUM> guides the microwaves that the magnetron <NUM> emitted into the cavity <NUM>. The waveguide <NUM> can be a tube made of metal, such as copper or aluminum. The magnetron <NUM> and waveguide <NUM> can be disposed between the cavity <NUM> (e.g., the side wall and/or floor <NUM> thereof) and an outer wall <NUM> of the cabinet <NUM>.

In embodiments, the microwave oven <NUM> further includes a turntable <NUM> and a motor <NUM> coupled to the turntable <NUM>. The turntable <NUM> is disposed within the cavity <NUM>. The motor <NUM> can be disposed within the cabinet <NUM>, under the floor <NUM> of the cavity <NUM>. The turntable <NUM> can be made of glass or some other heat-resistant material. When activated, the motor <NUM> causes the turntable <NUM> to rotate.

The cavity <NUM> provides an array <NUM> of positions 50a, 50b,. <NUM>n at which the user <NUM> can place the food item <NUM>. The array <NUM> of positions 50a, 50b,. <NUM>n is generally coextensive with a horizontal plane just above the floor <NUM>, or in embodiments of the microwave oven <NUM> that include the turntable <NUM>, a horizontal plane just above the turntable <NUM>. To illustrate, the food item <NUM> illustrated at <FIG> is placed at positions 50a-50d. However, the food item <NUM> is not placed at the position 50e or any other position 50n of the array <NUM>.

The microwave oven <NUM> further includes a human-machine interface <NUM>. The human-machine interface <NUM> is configured to provide an instruction <NUM> (see <FIG>) to the user <NUM>. In embodiments, the human-machine interface <NUM> includes a digital display <NUM>, at which the instruction <NUM> to the user <NUM> can be displayed. In addition, the human-machine interface <NUM> can include a speaker <NUM> to provide the instruction <NUM> to the user <NUM> audibly. The content of the instruction <NUM> will be further described below. In embodiments, the human-machine interface <NUM> is available at the door <NUM> of the microwave oven <NUM>. In other environments, the human-machine interface <NUM> is disposed at the cabinet <NUM>.

Referring additionally to <FIG> the microwave oven <NUM> further includes an infrared sensor <NUM>. The infrared sensor <NUM> includes an array <NUM> of pixels 62a, 62b,. Each pixel 62n corresponds to a different position <NUM>n of the array <NUM> of positions 50a, 50b,. 50n of the cavity <NUM>. For example, the pixel 62a corresponds to the position 50a, the pixel 62b corresponds to the position 50b, the pixel 62c corresponds to the position 50c, and the pixel 62d corresponds to the position 50d. In embodiments, the infrared sensor <NUM> has a field a view <NUM> that encompasses at least the perimeter <NUM> of the floor <NUM> of the cavity <NUM>. Accordingly, the array <NUM> of pixels 62a, 62b,. <NUM>n will at least encompass the array <NUM> of positions 50a, 50b,. <NUM>n of the cavity <NUM>. The infrared sensor <NUM> can be mounted above the ceiling <NUM>, with the cavity <NUM> visible through a window that is sufficiently transparent to infrared electromagnetic radiation. Each pixel <NUM>n generates an output.

Referring additionally to <FIG>, the microwave oven <NUM> further includes a controller <NUM>. The controller <NUM> can be housed in the cabinet <NUM>. In other embodiments, the controller <NUM> is housed in the door <NUM>. The controller <NUM> is in communication with the human-machine interface <NUM>, the infrared sensor <NUM>, the magnetron <NUM>, and the motor <NUM> that moves the turntable <NUM>, among other components as herein described. The communication can be via wired or wireless means (e.g., Wi-Fi, Bluetooth, and Zigbee), or a combination thereof.

The controller <NUM> controls the output of the human-machine interface <NUM>, such as the digital display <NUM> and the speaker <NUM>, if included. The controller <NUM> includes memory <NUM> and a processor <NUM>. The memory <NUM> stores programs and data, such as from the infrared sensor <NUM> and the human-machine interface <NUM>, that the processor <NUM> executes in furtherance of the controller <NUM> actions described herein. The memory <NUM> can be random access memory (RAM), read-only memory (ROM), and flash memory, among other possibilities. The processor <NUM> can be a microprocessor or a microcontroller, among other possibilities.

The controller <NUM> receives and processes the outputs that the infrared sensor <NUM> generates. More specifically, each pixel <NUM>n of the array <NUM> of pixels 62a, 62b,. <NUM>n of the infrared sensor <NUM> generates output that the controller <NUM> receives. The output of each pixel <NUM>n, typically a voltage, is proportional to the incident infrared energy, which in turn is proportional to the temperature. Accordingly, the controller <NUM> can determine a temperature at each position <NUM>n of the cavity <NUM> as a function of the output of each pixel 62n that correlates to that particular position <NUM>n. The output of each pixel <NUM>n is indicative of the temperature at the position <NUM>n in the cavity <NUM> to which the pixel <NUM>n corresponds. The controller <NUM> can thus determine a heat map (see e.g., <FIG>) of the cavity <NUM> corresponding to the temperature at each of the positions 50a, 50b,. <NUM>n of the cavity <NUM>.

The controller <NUM> is further configured to identify a rise and fall in the temperature at one or more of the positions <NUM>n of the array <NUM> of positions 50a, 50b,. <NUM>n within the cavity <NUM>. By monitoring the output that each pixel <NUM>n of the array <NUM> of pixels 62a, 62b,. 62n of the infrared sensor <NUM> generates as a function of time, the controller <NUM> can identify a short term change in output, for example, a rise and fall in voltage generated by one or more of the pixels 62a, 62b,. <NUM>n as a function of time. Because the array <NUM> of pixels 62a, 62b,. <NUM>n corresponds to the array <NUM> of positions 50a, 50b,. <NUM>n within the cavity <NUM>, the short term change in output, such as the rise and fall in voltage, can be equated with a rise and fall in temperature at the one or more positions 50a, 50b,. <NUM>n corresponding to the one or more pixels 62a, 62b,. <NUM>n showing the short term change in output. In embodiments, the controller <NUM> can be configured to require a certain number of contiguous pixels 62a, 62b,. <NUM>n generate a similar short term change in output as requisite to identifying a rise and fall in temperature. Other filters could be utilized to eliminate noise at the level of individual pixels 62a, 62b,.

In embodiments, the rise and fall in the temperature at the one or more positions 50a, 50b,. <NUM>n that the controller <NUM> is configured to recognize include rising from about room temperature to above <NUM> and then back to about room temperature. The temperature of the cavity <NUM> will likely be equalized with room temperature. Thus, room temperature here literally can mean the temperature of the external environment <NUM> (e.g., a room, a kitchen) in which the microwave oven <NUM> is located. In some instances, room temperature may be about <NUM>, but can be colder or warmer in other instances. A hand <NUM> of the user <NUM> in the external environment <NUM> having a room temperature of about <NUM> will typically have a temperature of about <NUM> to about <NUM>. However, the temperature of the hand <NUM> can be lower than <NUM> under a variety of circumstances, such as when the external environment <NUM> is cooler than <NUM>. Thus, the temperature of <NUM> is a reasonable minimum value for the signature of the hand <NUM>. In some instances, the temperature can be lower than <NUM>.

The rise and fall of the temperature that the controller <NUM> is configured to recognize can occur over a predefined time period. The user <NUM> action of placing the food item <NUM> within the cavity <NUM> takes a finite amount of time. If the rise and fall of the temperature is too quick - shorter than the predefined time period - then the controller <NUM> can be configured to disregard the rise and fall as noise. In some instances, the predefined period of time can be within a range of from <NUM> second to <NUM> seconds, although a period of time outside of that range may be appropriate.

The controller <NUM> is further configured to estimate the position <NUM>n or positions 50a, 50b,. <NUM>n of the array <NUM> of positions 50a, 50b,. <NUM>n within the cavity <NUM> that a food item <NUM> occupies as a function of the one or more positions 50a, 50b,. <NUM>n of the array <NUM> of positions 50a, 50b,. <NUM>n within the cavity <NUM> where the controller <NUM> recognized a rise and fall in temperature occurred. As mentioned, the rise and fall of temperature at the one or more positions 50a, 50b,. <NUM>n within the cavity <NUM> indicates the hand <NUM> of the user <NUM> entering the cavity <NUM> to deposit the food item <NUM> within the cavity <NUM> (e.g., upon the floor <NUM> or turntable <NUM>) and then leaving the cavity <NUM> to return to the external environment <NUM>. A trained algorithm can be generated that correlates the positions 50a, 50b,. <NUM>n that the hand <NUM> of the user <NUM> occupied, as a function of time, while depositing the food item <NUM> into the cavity <NUM> with the positions 50a, 50b,. <NUM>n that the food item <NUM> occupies after being so deposited. Various different hand <NUM> postures and entries into the cavity <NUM> can be correlated with different containers for the food item <NUM>, sizes of containers, and the positions 50a, 50b,. <NUM>n that the food item <NUM> occupies within the cavity <NUM>. The signature, in terms of positions 50a, 50b,. <NUM>n within the cavity <NUM> as a function of time, of the hand <NUM> depositing a cup of soup into the cavity <NUM> is different than the signature of the hand <NUM> depositing a plate of some food item <NUM>. The signature of a hand <NUM> depositing a small plate is different than the signature of a hand <NUM> depositing a large plate, and so on.

There are various machine learning techniques that can be utilized to generate the trained algorithm that can predict the positions 50a, 50b,. <NUM>n of the food item <NUM> as a function of the positions 50a, 50b,. <NUM>n that the hand <NUM> occupies while entering and leaving the cavity <NUM>. Supervised learning is an example, where datasets of examples are provided with the food item <NUM> and the hand <NUM> labeled. Once the algorithm is trained to predict the positions 50a, 50b,. <NUM>n of the food item <NUM> within the cavity <NUM> and a function of the position of the hand <NUM>, the trained algorithm can be further taught to equate output from the pixels 62a, 62b,. <NUM>n of the infrared sensor <NUM> with the positions 50a, 50b,. <NUM>n of the hand <NUM> in a similar manner. The trained algorithm would thus be able to predict the positions 50a, 50b,. <NUM>n of the food item <NUM> within the cavity <NUM> as a function of the outputs of the pixels 62a, 62b,. <NUM>n of the infrared sensor <NUM>. The trained algorithm is stored in memory <NUM> for the controller <NUM> to access and utilize while receiving output from the pixels 62a, 62b,. <NUM>n of the infrared sensor <NUM> in order to estimate the position 50n or positions 50a, 50b,. <NUM>n that the food item <NUM> occupies.

In embodiments, the machine learning technique utilizes a deep learning neural network. A deep learning neural network can be used to identify regions of interest in images. One example deep learning network is VGG16. VGG16 is a convolutional neural network architecture that can analyze an image, extract features therefrom, and pass the extracted features through a series of connected layers, which predict the content of the extracted features. For purposes of this disclosure, the VGG16 architecture can accept, as input, the output from the pixels 62a, 62b,. <NUM>n of the infrared sensor <NUM> and extract features therefrom, pass them through the series of connected layers, and conclude whether and where the hand <NUM> is positioned within the cavity <NUM> - for example, which of the positions 50a, 50b,. <NUM>n the hand <NUM> occupies.

Another example deep learning network is YOLO (short for You Only Look Once). The YOLO architecture processes an image (here, the output from the pixels 62a, 62b,. 62n of the infrared sensor <NUM> at a point in time) and predicts the location and classification of objects (e.g., the hand <NUM>) within the image. YOLO architecture allows for real-time or near real-time object detection from input image data. YOLO divides the input into a grid of cells and determines the presence of desired object(s) (e.g., the hand <NUM>) within each cell via a convolutional neural network. Thus, the YOLO architecture could identify that the hand <NUM> is within the cavity <NUM> and track the movement thereof - for example which of the positions 50a, 50b,. <NUM>n the hand <NUM> occupies as a function of time.

Other architectures can be considered with the objective of reducing the size and complexity of the network. This can depend on the type of sensor used, as the dimensions of the raw image can be different, changing the architecture of the neural network. A simplified version of the algorithm can be extracting elements of the temperature blob, like size, direction, angle, etc. This can be achieved by applying a clustering algorithm on the image and separate background from object, then extracting the elements mentioned above from the object.

In embodiments, the controller <NUM> is configured so that the positions 50a, 50b,. <NUM>n that the controller <NUM> estimates the food item <NUM> occupies are different than the positions 50a, 50b, <NUM>n where the controller <NUM> recognized the rise and fall in temperature occurred. This can be a consequence of the trained algorithm. As an example, consider the user <NUM> placing a plate holding the food item <NUM> into the cavity <NUM>. At the greatest progression of the hand <NUM> into the cavity <NUM>, the hand <NUM> occupies one set of positions 50a, 50b,. <NUM>n within the cavity <NUM> while the food item <NUM> occupies another set of positions 50a, 50b,. <NUM>n within the cavity <NUM>. In many instances, the hand <NUM> within the cavity <NUM> and the food item <NUM> do not fully overlap. In embodiments, the controller <NUM> estimates that the food item <NUM> occupies a position 50n or positions 50a, 50b,. <NUM>n that are directly rearward <NUM> of the one or more positions 50a, 50b,. <NUM>n where the controller <NUM> recognized the rise and fall in temperature occurred - for example, the food item <NUM> is estimated to be closer to the rear wall <NUM> than the one or more positions 50a, 50b,. <NUM>n where the controller <NUM> recognized the rise and fall in temperature occurred. There are likely exceptions, such as the hand <NUM> palming the food item <NUM>, such as a biscuit. Thus, in embodiments, the controller <NUM> estimates that the food item <NUM> occupies a position <NUM>n or positions 50a, 50b,. <NUM>n that are coextensive with or subsumed by the one or more positions 50a, 50b,. <NUM>n where the controller <NUM> recognized the rise and fall in temperature occurred.

The controller <NUM> is further configured to determine whether the position <NUM>n or positions 50a, 50b,. <NUM>n that the food item <NUM> is estimated to occupy is adequate for the controller <NUM> to determine accurately a temperature of the food item <NUM> during an automatic heating operation that utilizes the infrared sensor <NUM>. As mentioned, the microwave oven <NUM> is capable of heating the food item <NUM> without the user <NUM> having to set a fixed time of heating (e.g., <NUM> minutes). The microwave oven <NUM> performs that automatic heating function relying on the output from the infrared sensor <NUM>, from which the temperature of the food item <NUM> can be determined. Once a desirable temperature is achieved, the microwave oven <NUM> ceases the heating operation. However, the further the food item <NUM> is from the infrared sensor <NUM>, the less accurate the output of infrared sensor <NUM>. In other words, the pixels 62a, 62b,. <NUM>n of the infrared sensor <NUM> positioned to generate output correlating with positions 50a, 50b,. <NUM>n within the cavity <NUM> further away from infrared sensor <NUM> generate output that is less accurate than the output generated by pixels 62a, 62b,. <NUM>n correlated with positions 50a, 50b,. <NUM>n within the cavity <NUM> closer to the infrared sensor <NUM>. Various positions 50a, 50b,. <NUM>n within the cavity <NUM> can be predetermined as being too far from the infrared sensor <NUM>. If the controller <NUM> estimates that the food item <NUM> occupies those positions 50a, 50b,. <NUM>n that are too far away from the infrared sensor <NUM>, then the controller <NUM> determines that the positions 50a, 50b,. <NUM>n are inadequate for the controller <NUM> to determine accurately the temperature of the food item <NUM> during the automatic heating operation. However, if the controller <NUM> estimates that the food item <NUM> does not occupy those positions 50a, 50b,. 50n that are too far from the infrared sensor <NUM>, then the controller <NUM> determines that the positions 50a, 50b,. <NUM>n are adequate for the controller <NUM> to determine accurately the temperature of the food item <NUM> during the automatic heating operation.

The controller <NUM> is configured to perform these described actions (e.g., to determine the temperature at each position <NUM>n, to recognize the rise in fall in temperature, to estimate the positions 50a, 50b,. <NUM>n that the food item <NUM> occupies, and to determine whether the positions 50a, 50b,. <NUM>n are adequate for automatic heating) without first activating the magnetron <NUM> to increase the temperature of the food item <NUM>. As mentioned, instead of performing those actions, the controller <NUM> could activate the magnetron <NUM> and heat the food item <NUM> until the temperatures of the food item <NUM> and the cavity <NUM> respectively contrast sufficiently for the controller <NUM> to ascertain the positions 50a, 50b,. <NUM>n of the food item <NUM>. However, that takes time. And if the positions 50a, 50b,. <NUM>n of the food item <NUM> are inadequate to perform the automatic heating operation, then the microwave oven <NUM> would have to cease the heating operation and call for the user <NUM> to reposition the food. The approach of the present disclosure results in the controller <NUM> making the decision as to whether the positions 50a, 50b,. 50n of the food item <NUM> are adequate for the automatic heating operation without first causing the magnetron <NUM> to heat the food item <NUM>.

Referring now to <FIG>, in embodiments, the controller <NUM> is further configured to cause the human-machine interface <NUM> to issue the instruction <NUM> to the user <NUM>. In embodiments, the instruction <NUM> to the user <NUM> is to reposition the food item <NUM> within the cavity <NUM>. The repositioning of the food item <NUM> is so that the food item <NUM> occupies a position 50n or positions 50a, 50b,. 50n that are adequate for the controller <NUM> to determine accurately the temperature of the food item <NUM> during the automatic heating operation. After the user <NUM> repositions the food item <NUM>, the controller <NUM> again (i) recognizes the rise and fall in at one or more positions 50a, 50b,. <NUM>n within the cavity <NUM> due to the hand <NUM> entering the cavity <NUM> and (ii) estimates the positions 50a, 50b,. <NUM>n within the cavity <NUM> that the food item <NUM> occupies. In embodiments, the algorithm that the controller <NUM> utilizes is specifically trained with repositioning data, as the hand <NUM> movement and posture during repositioning may be different than the hand <NUM> movement and posture during the initial positioning of the food item <NUM> within the cavity <NUM>. The human-machine interface <NUM> can utilize the digital display <NUM> to issue the instruction <NUM> visibly, the speaker <NUM> to issue the instruction <NUM> audibly, or a combination of the two. After the user <NUM> repositions the food item <NUM> to an adequate position <NUM>n or positions 50a, 50b,. <NUM>n, then the controller <NUM> commences the automatic heating operation.

In embodiments, the controller <NUM> is further configured to cause the motor <NUM> to rotate the turntable <NUM> to reposition the food item <NUM> within the cavity <NUM> to occupy a position 50n or positions 50a, 50b,. <NUM>n that is adequate for the controller <NUM> to determine accurately the temperature of the food item <NUM> during the automatic heating operation. For example, if the controller <NUM> determines that the food item <NUM> occupying position 50e (see <FIG>) is inadequate, and that position 50f would be adequate, then the controller <NUM> can cause the turntable <NUM> to rotate the food item <NUM> from the position 50e to the position 50f. After the turntable <NUM> repositions 50a, 50b,. <NUM>n the food item <NUM> to an adequate position <NUM>n or positions 50a, 50b,. <NUM>n, then the controller <NUM> commences the automatic heating operation.

Referring back to <FIG> and <FIG>, in embodiments, the microwave oven <NUM> includes a time of flight sensor <NUM>. The time of flight sensor <NUM> is positioned to generate output from which it can be determined whether an object, such as the hand <NUM> of the user <NUM>, is approaching the cavity <NUM> of the microwave. For example, the time of flight sensor <NUM> can be placed at the cabinet <NUM> inside the door <NUM> elevationally, such as elevationally lower than the floor <NUM> of the cavity <NUM> or elevationally higher than the ceiling <NUM> of the cavity <NUM>. The time of flight sensor <NUM> utilizes a light or radio signal to travel from the sensor to the object and back to the sensor again. The time of flight sensor <NUM> can be a LIDAR sensor or an ultrasonic sensor, among other options. The controller <NUM> can use the output of the time of flight sensor <NUM> to determine that an object, such as the hand <NUM> of the user <NUM> with the food item <NUM>, is approaching the cavity <NUM>. In embodiments, the controller <NUM> determines, as a function of the output of the time of flight sensor <NUM>, that an object is approaching the cavity <NUM> before analyzing the output from the array <NUM> of pixels 62a, 62b,. <NUM>n of the infrared sensor <NUM> to determine the temperature at each position 50n within the cavity <NUM> and before attempting to recognize whether there has been a rise and fall in temperature at any of the positions 50a, 50b,. The controller <NUM> can utilize the output of the time of flight sensor <NUM> as a cue to begin processing the output from the infrared sensor <NUM>. If no object is approaching the cavity <NUM>, then there is no need for the controller <NUM> to expend resources to process the output of the infrared sensor <NUM>. If an object is approaching the cavity <NUM>, as determined via analyzing the output of the time of flight sensor <NUM>, then the controller <NUM> can begin processing the output from the infrared sensor <NUM>. The time of flight sensor <NUM> can increase the energy efficiency of the microwave oven <NUM>.

In embodiments, the microwave oven <NUM> includes a light curtain <NUM>. The light curtain <NUM> includes one or more pairs of a transmitter <NUM> of electromagnetic radiation and a receiver <NUM> of electromagnetic radiation. One transmitter <NUM> is paired with one receiver <NUM>, another transmitter <NUM> is paired with another receiver <NUM>, and so on. The electromagnetic radiation that the transmitter <NUM> is configured to emit, and that the receiver <NUM> is configured to receive, can be red visible light or infrared radiation, among other options. The light curtain <NUM> is in communication with the controller <NUM>.

The light curtain <NUM> is positioned to generate output from which the controller <NUM> can determine whether an object (e.g., a hand <NUM>, a plate with the food item <NUM>, etc.) has crossed, or is about to cross, the opening <NUM> into the cavity <NUM>. For example, the one or more pairs of the transmitter <NUM> and the receiver <NUM> can be disposed proximate the opening <NUM> into the cavity <NUM>, such as just inside the cavity <NUM> at the sidewall <NUM> and the sidewall <NUM> respectively. The pairs of transmitters <NUM> and receivers <NUM> can be positioned elevationally, in a spaced apart fashion, along a height <NUM> of the cavity <NUM> from the floor <NUM> to the ceiling <NUM>. The positioning of, and the elevational distance between adjacent, transmitters <NUM> and receivers <NUM> ought to be sufficient to detect an object regardless of where elevationally the object crosses the opening <NUM> into the cavity <NUM> (e.g., sufficient to detect the object crossing substantially anywhere along the height <NUM>). The transmitter <NUM> emits electromagnetic radiation that the receiver <NUM> is positioned to receive. The receiver <NUM> generates an output that changes as a function of whether the receiver <NUM> is receiving the electromagnetic radiation that the transmitter <NUM> emits. If an object is not disposed between the transmitter <NUM> and the receiver <NUM>, then the receiver <NUM> receives the electromagnetic radiation that the transmitter <NUM> transmits. In contrast, if an object is disposed between the transmitter <NUM> and the receiver <NUM>, then the receiver <NUM> does not receive the electromagnetic radiation that the transmitter <NUM> transmits, and the output of the receiver <NUM> changes compared to when the receiver <NUM> was receiving the electromagnetic radiation. The controller <NUM> can thus recognize the change in output of the receiver <NUM> and conclude that an object has crossed the opening <NUM> into the cavity <NUM>.

In embodiments, the controller <NUM> determines, as a function of the output of the light curtain <NUM>, that an object has crossed the opening <NUM> into the cavity <NUM> before analyzing the output from the array <NUM> of pixels 62a, 62b,. <NUM>n of the infrared sensor <NUM> to determine the temperature at each position 50n within the cavity <NUM> and before attempting to recognize whether there has been a rise and fall in temperature at any of the positions 50a, 50b,. The controller <NUM> can utilize the output of the receiver <NUM> of the light curtain <NUM> as a cue to begin processing the output from the infrared sensor <NUM>. If no object has crossed the opening <NUM> into the cavity <NUM>, then there is no need for the controller <NUM> to expend resources to process the output of the infrared sensor <NUM>. If an object has crossed the opening <NUM> into the cavity <NUM>, as determined via analyzing the output of the light curtain <NUM>, then the controller <NUM> can begin processing the output from the infrared sensor <NUM>. In many scenarios, a food item <NUM> (or container or dishware holding the food item <NUM>) crosses the opening <NUM> into the cavity <NUM> before the hand <NUM>. Thus, in many scenarios, the controller <NUM> will have sufficient time to analyze the output from the infrared sensor <NUM> to determine the presence and signature of the hand <NUM> after noticing a change in output of the light curtain <NUM> due to the food item <NUM>.

In embodiments, the microwave oven <NUM> includes a door sensor <NUM>. The door sensor <NUM> is in communication with the controller <NUM>. The door sensor <NUM> generates an output that changes as a function whether the door <NUM> is in the closed position <NUM> or the open position <NUM>. For example, the door sensor <NUM> can include a magnet coupled to the door <NUM> and a reed switch coupled to the cabinet <NUM> near where the magnet is when the door <NUM> is in the closed position <NUM>. When the door <NUM> is in the closed position <NUM>, a magnetic field of the magnet closes metal reeds of the reed switch to contact and close an electrical circuit in communication with the controller <NUM>. When the door <NUM> moves to the open position <NUM>, the metal reeds separate and the electrical circuit becomes open. The controller <NUM> notices the change in output and can thus deduce whether the door <NUM> is in the closed position. Other arrangements than the magnet and reed switch are possible for the door sensor <NUM>.

In embodiments, the controller <NUM> is further configured to determine, as a function of the output generated by the door sensor <NUM>, that the door <NUM> has moved away from the closed position <NUM> toward the open position <NUM> before determining the temperature at each position of the array <NUM> of positions 50a, 50b,. <NUM>n of the cavity <NUM> and before attempting to recognize whether there has been a rise and fall in temperature at any of the positions 50a, 50b,. The controller <NUM> can utilize the output of the door sensor <NUM> as a cue to begin processing the output from the infrared sensor <NUM>. If the door <NUM> is in the closed position <NUM>, then there is no need for the controller <NUM> to expend resources to process the output of the infrared sensor <NUM>. The user <NUM> cannot place a food item <NUM> into the cavity <NUM> from the external environment <NUM> when the door <NUM> is in the closed position. If the door <NUM> has moved away from the closed position <NUM> toward the open position <NUM>, as determined via analyzing the output of the door sensor <NUM>, then the controller <NUM> can begin processing the output from the infrared sensor <NUM>.

Referring now to <FIG>, in another embodiment of the microwave oven 10A, instead of utilizing the output generated by the array <NUM> of pixels 62a, 62b,. <NUM>n of the infrared sensor <NUM> to estimate the position 50n or positions 50a, 50b,. <NUM>n that the food item <NUM> occupies as with the microwave oven <NUM>, the controller <NUM> can rely upon one or more sensors <NUM> (other than the infrared sensor <NUM>). The one or more sensors <NUM> are in communication with the controller <NUM>. The microwave oven 10A can otherwise be the same as the microwave oven <NUM> described above, without the need to restate the above discussion and drawings. The microwave oven 10A still includes the infrared sensor <NUM> to determine the temperature of the food item <NUM> during the automatic heating operation of the food item <NUM> but not to determine the position <NUM>n or positions 50a, 50b,. <NUM>n of the food item <NUM> before the automatic heating operation begins.

In embodiments, the one or more sensors <NUM> can include at least three sensors 84a-84c. Each of the at least three sensors 84a-84c has a field of view 86a-86c that is different than the field of view 86a-86c of the other sensors 84a-84c of the at least three sensors 84a-84c. For example, the sensor 84a can have a field of view 86a, the sensor 84b can have a field of view 86b, and the sensor 84c can have a field of view 86c. In some instances, the adjacent fields of view 86a-86c overlap. The fields of view 86a-86c can include the opening <NUM> into the cavity <NUM> and the external environment <NUM> adjacent to the opening <NUM> when the door <NUM> is in the open position <NUM>. The at least three sensors 84a-84c can include time of flight sensors, a light curtain, one-pixel infrared sensors, among other options.

The one or more sensors <NUM> are positioned to generate output that is indicative of whether and where laterally <NUM> (e.g., where between the sidewalls <NUM>, <NUM>) an object enters the opening <NUM> from the external environment <NUM> into the cavity <NUM>. For example, in the illustrated scenario with the at least three sensors 84a-84c, the object entering the opening <NUM> into the cavity <NUM> through a region 90a would cause a change in output of the sensor 84c because the region 90a is within the field of view 86c of the sensor 84c. The controller <NUM> can then understand that an object, such as plate holding a food item <NUM>, is entering the cavity <NUM> from that region 90a. The object entering the opening <NUM> into the cavity <NUM> through a region 90b would cause a change in output of both the sensor 84b and the sensor 84c. The controller <NUM> can then understand that the object is entering the cavity <NUM> from that region 90b. The greater the number of sensors <NUM>, the more precisely the controller <NUM> can determine from changes in output of the sensors <NUM> the region 90n where the object crosses the opening <NUM> into the cavity <NUM> from the external environment <NUM>.

In turn, the controller <NUM> can estimate the position 50n or positions 50a, 50b,. 50n within the cavity <NUM> that the food item <NUM> occupies as a function of the output of the one or more sensors <NUM>. After the controller <NUM> determines the region 90n where the object crosses the opening <NUM> into the cavity <NUM> from the external environment <NUM>, the controller <NUM> can estimate the position 50n or positions 50a, 50b,. <NUM>n at which the object (e.g., the food item <NUM>) resides within the cavity <NUM>. This correlation between region 90n of entry into the cavity <NUM> and position <NUM>n or positions 50a, 50b,. <NUM>n within the cavity <NUM> that the object (e.g., food item <NUM>) is estimated to reside can be predetermined. For example, after the controller <NUM> determines that the object (e.g., the food item <NUM>) entered the cavity <NUM> via the region 90a, the controller <NUM> can estimate that the object resides at one or more of the positions <NUM>n in the columns of positions 50n rearward <NUM> of positions <NUM>-50i adjacent to the opening <NUM>. In embodiments, the controller <NUM> is configured to estimate that the food item <NUM> occupies positions <NUM>n rearward <NUM> of the positions <NUM>n adjacent to the region 90n where the food item <NUM> crossed the opening <NUM> into the cavity <NUM>. In embodiments, the controller <NUM> estimates the position 50n or positions 50a, 50b,. <NUM>n of the food item <NUM> within the cavity <NUM> as a function of which of the at least three sensors 84a-84c generated output indicative of the object entering the opening <NUM> into the cavity <NUM>.

The controller <NUM> is further configured to determine whether the position <NUM>n or positions 50a, 50b,. <NUM>n that the food item <NUM> is estimated to occupy is adequate for the controller <NUM> to determine accurately a temperature of the food item <NUM> during the automatic heating operation that utilizes the infrared sensor <NUM>. It can be predetermined, for example, that a food item <NUM> placed relatively close to the sidewalls <NUM>, <NUM>, such as occupying the columns of positions <NUM>n rearward <NUM> of the positions <NUM>-50i in the illustrated scenario, is inadequately positioned for the controller <NUM> to determine accurately a temperature of the food item <NUM> during the automatic heating operation. In some instances, the positions 50a, 50b,. <NUM>n that are inadequate for the controller <NUM> depend on the location of the infrared sensor <NUM>.

As with the microwave oven <NUM>, the controller <NUM> for the microwave oven <NUM> is further configured to cause the human-machine interface <NUM> to issue the instruction <NUM> to the user <NUM> to reposition the food item <NUM> to occupy a position 50n or positions 50a, 50b,. <NUM>n that is adequate for the controller <NUM> to determine accurately the temperature of the food item <NUM> during the automatic heating operation. After the user <NUM> does so, and moves the door <NUM> to the closed position <NUM>, the controller <NUM> initiates the magnetron <NUM> and performs the automatic heating operation until the controller <NUM> determines, based on the output from the infrared sensor <NUM>, that the food item <NUM> has reached a desired temperature.

Referring now to <FIG>, a method <NUM> of operating a microwave oven (such as the microwave oven <NUM> or the microwave oven 10A) is herein disclosed. At a step <NUM>, the method <NUM> includes estimating the position <NUM>n or positions 50a, 50b,. <NUM>n within the cavity <NUM> that the food item <NUM> occupies, without first heating the food item <NUM> within the cavity <NUM>. As further elaborated above, in embodiments, estimating the position 50n or positions 50a, 50b,. <NUM>n that the food item <NUM> occupies includes (i) determining a temperature at each of the positions 50a, 50b,. <NUM>n within the cavity <NUM>, (ii) recognizing a rise and fall in the temperature at one or more of the positions 50a, 50b,. <NUM>n within the cavity <NUM>, and (iii) estimating the position 50n or positions 50a, 50b,. <NUM>n within the cavity <NUM> that the food item <NUM> occupies as a function of the one or more positions 50a, 50b,. <NUM>n where the rise and fall in temperature was recognized to occur.

The temperature at each of the positions 50a, 50b,. <NUM>n within the cavity <NUM> can be determined with the infrared sensor <NUM> of the microwave oven <NUM>. The output that the pixels 62a, 62b,. <NUM>n of the infrared sensor <NUM> generates can be utilized to determine the temperature at the positions 50a, 50b,. <NUM>n within the cavity <NUM>, although other ways are possible. Recognizing the rise and fall in temperature can be achieved by monitoring the output of the pixels 62a, 62b,. <NUM>n as a function of time. The infrared sensor <NUM> that generates the output for that determination can be the same infrared sensor <NUM> that is utilized to determine the temperature of the food item <NUM> during an automatic heating operation. The rise and fall in the temperature can include a rise from about room temperature to above <NUM> and then back down to about room temperature. As discussed above, a rise and fall in temperature of that magnitude can be assumed to indicate the entry of the hand <NUM> of the user <NUM> into the cavity <NUM> (e.g., to deposit the food item <NUM>) and the subsequent withdrawal of the hand <NUM> from the cavity <NUM>. Other temperature ranges for the rise and fall of temperature can indicate the entry and withdrawal of the hand <NUM> into and from the cavity <NUM>.

Estimating the position <NUM>n or positions <NUM>n that the food item <NUM> occupies as a function of the one or more positions 50a, 50b,. <NUM>n where the rise and fall in temperature was recognized to occur can be done in a variety of ways. One example, as described above, is to train an algorithm that correlates the position of food as a function of the hand <NUM> position and posture within the microwave, and that correlates the hand <NUM> position and posture within the microwave with temperature as a function of position <NUM>n. Another example is to make an assumption regarding the positions 50a, 50b,. <NUM>n of the food item <NUM> as a function of the rise and fall in temperature. With such an assumption, the position 50n or positions 50a, 50b,. <NUM>n that the food item <NUM> is estimated to occupy can be at least partially different than the one or more positions 50a, 50b,. <NUM>n where the rise and fall in temperature was recognized to occur. For example, it can be assumed the food item <NUM> occupies positions 50a, 50b,. <NUM>n directly rearward <NUM> of positions 50a, 50b,. <NUM>n where the rise and fall in temperature was recognized to occur.

At a step <NUM>, the method <NUM> further includes determining the position <NUM>n or positions 50a, 50b,. 50n that the food item <NUM> is estimated to occupy at the step <NUM> is suboptimal for the microwave oven <NUM> to determine accurately, with the infrared sensor <NUM> of the oven, a temperature of the food item <NUM> during the automatic heating operation of the food item <NUM>. For example, it can be predetermined that certain of the positions 50a, 50b,. <NUM>n within the cavity <NUM> are not well positioned relative to the infrared sensor <NUM> for the infrared sensor <NUM> to produce output from which temperature can be determined with sufficient accuracy.

In embodiments, the method <NUM> further includes, at a step <NUM>, determining that an object is approaching the cavity <NUM> of the microwave, before the step <NUM> of estimating the position <NUM>n or positions 50a, 50b,. <NUM>n that the food item <NUM> occupies. As described above, determining that an object is approaching the cavity <NUM> can be a cue that the food item <NUM> may soon be occupying a position 50n or positions 50a, 50b,. <NUM>n of the food cavity <NUM>. It may take less processing power to first determine that an object is approaching the cavity <NUM> before determining the temperature at each position 50n within the cavity <NUM> than always determining the temperature at each position 50n within the cavity <NUM>. It can be determined that the object is approaching the cavity <NUM> in a variety of ways, such as a sensor disposed near the opening <NUM> into the cavity <NUM>. Examples of appropriate sensors include a time of flight sensor <NUM> or a light curtain <NUM>.

In embodiments, the method <NUM> further includes, at a step <NUM>, determining that that the door <NUM> of the microwave oven <NUM> has moved from the closed position <NUM> toward the open position <NUM>, before estimating the position <NUM>n or positions 50a, 50b,. <NUM>n that the food item <NUM> occupies. Again, determining that the door <NUM> has moved from the closed position <NUM> to the open position <NUM> can be a cue that the food item <NUM> may soon be occupying a position <NUM>n or positions 50a, 50b,. <NUM>n of the food cavity <NUM>. It may take less processing power to first determine that the door <NUM> is opening <NUM> before determining the temperature at each position 50n within the cavity <NUM> than always determining the temperature at each position <NUM>n within the cavity <NUM>. It can be determined that the door <NUM> is opening <NUM> in a variety of ways, such as with a door sensor <NUM>.

In embodiments, the method <NUM> further includes, at a step <NUM>, issuing the instruction <NUM> into the external environment <NUM> calling for the repositioning of the food item <NUM> within the cavity <NUM> to occupy a new position <NUM>n or positions 50a, 50b,. <NUM>n within the cavity <NUM>. The instruction <NUM> can be issued visibly via the digital display <NUM> at the human-machine interface <NUM>, or audibly via the speaker <NUM>, among other ways. The user <NUM> of the microwave oven <NUM> thus knows to reposition the food item <NUM>. The user <NUM> then repositions the food item <NUM> after receiving the instruction <NUM>.

In embodiments, the method <NUM> further includes, at a step <NUM>, activating the turntable <NUM> to reposition the food item <NUM> to a new position <NUM>n or positions 50a, 50b,. <NUM>n within the cavity <NUM> that is more optimal for the microwave oven <NUM> to determine accurately, with the infrared sensor <NUM>, the temperature of the food item <NUM> during the heating operation of the food item <NUM>. Instead or in addition to the step <NUM> of issuing the instruction <NUM> and relying on the user <NUM> to reposition the food item <NUM>, the microwave oven <NUM> can utilize the turntable <NUM> to place the food item <NUM> in a position <NUM>n or positions 50a, 50b,. <NUM>n that would allow the output of the infrared sensor <NUM> to more accurately indicate the temperature of the food item <NUM>.

In embodiments, after the steps <NUM>, <NUM> resulting in the repositioning the food item <NUM>, the method <NUM> further includes the step <NUM> of heating the food item <NUM>. The heating can be the microwave oven <NUM> automatically heating the food item <NUM> until the food item <NUM> reaches a desired temperature. The microwave oven <NUM> can determine the desired temperature, or the user <NUM> can inform the microwave oven <NUM> what is the desired temperature. The microwave oven <NUM> can determine the temperature of the food item <NUM> using the output of the infrared sensor <NUM>.

The principles disclosed here have been in the context of the microwave oven <NUM>. However, the principles can be extended to household appliances generally. For example, monitoring into which region (e.g., shelf) of a refrigerator a hand <NUM> enters can be utilized to direct cold to that region on the assumption that the hand <NUM> deposited a heat load (e.g., a recently heated food item <NUM>) at that region.

Example <NUM> - For Example <NUM>, in reference to <FIG>, a mug full of water at about ambient temperature was placed within the cavity of a microwave oven that was also at about ambient temperature. The output of each of the pixels of the pixel array of the infrared sensor associated with the microwave oven was obtained at a particular point in time. Each pixel corresponds with a different position within the cavity. The temperature at each position within the cavity was calculated as a function of the output of each pixel. The temperatures were then plotted graphically as a function of position with the cavity (or as function of pixel position within the array of pixels). The graph is reproduced at <FIG>. Because the cavity, the water, and the mug are all at about ambient temperature, the plot does not reveal a temperature contrast or any other signature from which the positions of the water can be determined.

Example <NUM> - For Example <NUM>, in reference to <FIG>, a frozen beef patty was placed within the cavity of a microwave oven that was at about ambient temperature. The output of each of the pixels of the pixel array of the infrared sensor associated with the microwave oven was obtained at a particular point in time. Each pixel corresponds with a different position within the cavity. The temperature at each position within the cavity was calculated as a function of the output of each pixel. The temperatures were then plotted graphically as a function of position with the cavity (or as function of pixel position within the array of pixels). The graph is reproduced at <FIG>. Because the temperature of the beef patty contrasts with the temperature of the remainder of the cavity, the output of the infrared sensor can be readily utilized to determine the positions that the beef patty occupies. As the beef patty is relatively centrally placed within the cavity, the microwave oven could automatically heat the beef patty and adequately monitor the temperature thereof until a predetermined temperature is reached.

Examples 3A and 3B - For Examples 3A and 3B, in reference to <FIG>, a hand entered with a mug of room temperature water, deposited the mug, and exited the cavity of the microwave. For Example 3A, the hand entered and exited toward the left sidewall of the cavity. For Example 3B, the hand entered and exited more toward the midline of the cavity (e.g., approximately equidistant from each sidewall). The output of each of the pixels of the pixel array of the infrared sensor associated with the microwave oven was obtained at a particular point in time for each of the examples. Each pixel corresponds with a different position within the cavity. The temperature at each position within the cavity was calculated as a function of the output of each pixel. The temperatures were then plotted graphically as a function of position within the cavity (or as function of pixel position within the array of pixels). The graphs for each example is reproduced at <FIG> (for Example 3A) and <FIG> (for Example 3B). Because the temperature of the hand contrasts with the temperature of the remainder of the cavity, the output of the infrared sensor can be readily utilized to determine the positions that the hand occupies at the particular point in time. The water and mug, being at room temperature like the cavity, were not identifiable with the infrared sensor.

In addition, the maximum temperature calculated from the output of the pixels of the infrared sensor was ascertained as a function of time covering before the hand entered the cavity, while the hand was in the cavity, and after the hand exited the cavity. The maximum temperature as a function of time was graphed. The graph is reproduced at <FIG>. As the graph reveals, the entry and exit of the hand into the cavity causes a rise and fall of the maximum temperature within the cavity as a function of time. The temperatures derived from the individual pixels corresponding to the positions within the cavity at which the hand resided would also reveal a rise and fall in temperature.

According to a first aspect of the present disclosure, a microwave oven comprises: (a) a cavity configured to accept a food item for heating, the cavity providing an array of positions at which the food item can be placed; (b) an infrared sensor comprising an array of pixels, each pixel configured to generate an output and each pixel corresponding to a different position of the array of positions of the cavity; (c) a human-machine interface configured to provide an instruction to the user; and (d) a controller in communication with the infrared sensor and the human-machine interface, the controller configured: (i) to determine a temperature at each position of the array of positions of the cavity as a function of the output of each pixel of the array of pixels; (ii) to recognize a rise and fall in the temperature at one or more positions of the array of positions within the cavity; (iii) to estimate the position or positions of the array of positions within the cavity that a food item occupies as a function of the one or more positions of the array of positions within the cavity where the controller recognized a rise and fall in temperature occurred; and (iv) to determine whether the position or positions that the food item is estimated to occupy is adequate for the controller to determine accurately a temperature of the food item during an automatic heating operation that utilizes the infrared sensor.

According to a second aspect of the present disclosure, the microwave oven of the first aspect further comprises a magnetron in communication with the controller, wherein, the controller is further configured to perform (i)-(iv) without first activating the magnetron to increase the temperature of the food item.

According to a third aspect of the present disclosure, the microwave oven of any one of the first through second aspects is presented, wherein the controller is further configured to cause the human-machine interface to issue an instruction to the user to reposition the food item within the cavity to occupy a position or positions that is adequate for the controller to determine accurately the temperature of the food item during the automatic heating operation that utilizes the infrared sensor.

According to a fourth aspect of the present disclosure, the microwave oven of any one of the first through third aspects further comprises: (i) a turntable within the cavity; and (ii) a motor coupled to turntable, the motor in communication with the controller, wherein, the controller is further configured to cause the motor to rotate the turntable to reposition the food item within the cavity to occupy a position or positions that is adequate for the controller to determine accurately the temperature of the food item during the automatic heating operation that utilizes the infrared sensor.

According to a fifth aspect of the present disclosure, the microwave oven of any one of the first through fourth aspects is presented, wherein the rise and fall in the temperature at the one or more positions that the controller is configured to recognize comprise rising from about room temperature to above <NUM> and then back down to about room temperature.

According to a sixth aspect of the present disclosure, the microwave oven of any one of the first through fifth aspects is presented, wherein (i) the controller further comprises a memory and a trained algorithm stored within the memory; and (ii) the controller is configured to utilize the trained algorithm to estimate the position or positions that the food item occupies.

According to a seventh aspect of the present disclosure, the microwave oven of any one of the first through sixth aspects is presented, wherein the controller is configured so that the position or positions that the controller estimates the food item occupies is different or are different than the one or more positions where the rise and fall in temperatures was recognized to occur.

According to an eighth aspect of the present disclosure, the microwave oven of any one of the first through seventh aspects is presented, wherein the infrared sensor comprises a field of view that encompasses at least a perimeter of a floor of the cavity.

According to a ninth aspect of the present disclosure, the microwave oven of any one of the first through sixth aspects is presented, wherein the controller is configured so that the position or positions that the controller estimates the food item occupies either is coextensive with, subsumed by, or is directly rearward of the one or more positions where the controller recognized the rise and fall in temperature occurred.

According to a tenth aspect of present disclosure, the microwave oven of any one of the first through ninth aspects further comprises a time of flight sensor in communication with the controller, the time of flight sensor positioned to generate output from which it can be determined whether an object is approaching the cavity of the microwave oven, wherein, the controller is further configured to determine, as a function of the output generated by the time of flight sensor, that an object is approaching the cavity of the microwave before determining the temperature at each position of the array of positions of the cavity as a function of the output of each pixel of the array of pixels.

According to an eleventh aspect of the present disclosure, the microwave oven of any one of the first through ninth aspects further comprises a light curtain in communication with the controller, the light curtain positioned to generate output from which it can be determined whether an object has crossed an opening into the cavity, wherein, the controller is further configured to determine, as a function of the output generated by the light curtain, that an object has crossed the opening into the cavity before determining the temperature at each position of the array of positions of the cavity as a function of the output of each pixel of the array of pixels.

According to a twelfth aspect of the present disclosure, the microwave oven of any one of the first through eleventh aspects further comprises: (a) a door comprising (i) a closed position denying a user access to the cavity from an external environment and (ii) an open position allowing the user access to the cavity from the external environment; and (b) a door sensor in communication with the controller, the door sensor configured to generate output that changes as a function of whether the door is in the closed position or the open position, wherein, the controller is further configured to determine, as a function of the output generated by the door sensor, that the door has moved away from the closed position toward the open position before determining the temperature at each position of the array of positions of the cavity as a function of the output of each pixel of the array of pixels.

According to a thirteenth aspect of the present disclosure, a microwave oven comprises (a) a cabinet comprising a floor, a ceiling, and opposing sidewalls defining a cavity configured to accept a food item for heating and an opening into the cavity from an external environment; (b) one or more sensors positioned to generate output indicative of whether and where laterally an object enters the opening from the external environment into the cavity; (c) a human-machine interface configured to provide an instruction to the user; (d) an infrared sensor configured to determine a temperature of the food item during an automatic heating operation of the food item; and (e) a controller in communication with the one or more sensors and the human-machine interface, the controller configured: (i) to estimate a position or positions within the cavity that a food item occupies as a function of the output of the one or more sensors; and (ii) to determine whether the position or positions that the food item is estimated to occupy is adequate for the controller to determine accurately the temperature of the food item during the automatic heating operation.

According to a fourteenth aspect of the present disclosure, the microwave oven of the thirteenth aspect is presented, wherein (i) the one or more sensors comprises at least three sensors, each of the at least three sensors having a field of view that is different than the field of view of the other sensors of the at least three sensors; and (ii) the controller is further configured to estimate the position or positions of the food item within the cavity as a function of which of the at least three sensors generated output indicative of the object entering the opening into the cavity from the external environment.

According to a fifteenth aspect of the present disclosure, the microwave oven of the fourteenth aspect is presented, wherein the at least three sensors are time of flight sensors.

According to a sixteenth aspect of the present disclosure, the microwave oven of the fourteenth aspect is presented, wherein the at least three sensors are one-pixel infrared sensors.

According to a seventeenth aspect of the present disclosure, the microwave oven of the fourteenth aspect is presented, wherein the at least three sensors are components of a light curtain.

According to an eighteenth aspect of the present disclosure, the microwave oven of any one of the thirteenth through seventeenth aspects is presented, wherein the controller is further configured (iii) to cause the human-machine interface to issue an instruction to the user to reposition the food item within the cavity to occupy a position or positions that is adequate for the controller to determine accurately the temperature of the food item during the automatic heating operation.

According to a nineteenth aspect of the present disclosure, a method of operating a microwave oven comprises: (a) estimating one or more positions within a cavity of a microwave oven that a food item occupies, without first heating the food item within the cavity; and (b) determining that the one or more positions that the food item is estimated to occupy is suboptimal for the microwave oven to determine accurately, with an infrared sensor of the microwave oven, a temperature of the food item during an automatic heating operation of the food item.

According to a twentieth aspect of the present disclosure, the method of the nineteenth aspect further comprises determining that an object is approaching the cavity of the microwave, before estimating the position or positions that the food item occupies.

According to a twenty-first aspect of the present disclosure, the method of any one of the nineteenth through twentieth aspects further comprises determining that a door of the microwave oven has moved from a closed position denying access to the cavity from the external environment toward an open position allowing access to the cavity from the external environment, before estimating the one or more positions that the food item occupies.

According to a twenty-second aspect of the present disclosure, the method of any one of nineteenth through twenty-first aspects further comprises: (i) issuing an instruction into the external environment calling for the repositioning of the food item within the cavity to occupy a new position or positions within the cavity; and (ii) after the food item is repositioned, heating the food item.

According to a twenty-third aspect of the present disclosure, the method of any one of the nineteenth through twenty-first aspects further comprises: (i) activating a turntable to reposition the food item to a new position or positions within the cavity that is more optimal for the microwave oven to determine accurately, with the infrared sensor, the temperature of the food item during the heating operation of the food item; and (ii) after the food item is repositioned, heating the food item.

According to a twenty-fourth aspect of the present disclosure, the method of any one of the nineteenth through twenty-third aspects is presented, wherein estimating the one or more positions within the cavity that the food item occupies comprises (i) determining a temperature at one or more positions within the cavity, (ii) recognizing a rise and fall in the temperature at the one or more of the positions within the cavity, and (iii) estimating the one or more positions within the cavity that the food item occupies as a function of the one or more positions where the rise and fall in temperature was recognized to occur.

According to a twenty-fifth aspect of the present disclosure, the method of the twenty-fourth aspect is presented, wherein the rise and fall in the temperature at the one or more positions includes a rise from about room temperature to above <NUM> and then back down to about room temperature.

According to a twenty-sixth aspect of the present disclosure, the method of any one of the twenty-fourth through twenty-fifth aspects is presented, wherein the one or more positions within the cavity that the food item is estimated to occupy is at least partially different than the one or more positions of the cavity where the rise and fall in temperature was recognized to occur.

It is also important to note that the construction and arrangement of the elements of the disclosure as shown in the exemplary embodiments is illustrative only. Although only a few embodiments of the present innovations have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts or elements shown as multiple parts may be integrally formed, the operation of the interfaces may be reversed or otherwise varied, the length or width of the structures and/or members or connector or other elements of the system may be varied, the nature or number of adjustment positions provided between the elements may be varied. It should be noted that the elements and/or assemblies of the system may be constructed from any of a wide variety of materials that provide sufficient strength or durability, in any of a wide variety of colors, textures, and combinations. Accordingly, all such modifications are intended to be included within the scope of the present innovations. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the desired and other exemplary embodiments without departing from the spirit of the present innovations.

Claim 1:
A microwave oven (<NUM>) comprising:
a cavity (<NUM>) configured to accept a food item (<NUM>) for heating, the cavity (<NUM>) providing an array (<NUM>) of positions (50a, 50b, . . . <NUM>n) at which the food item (<NUM>) can be placed;
an infrared sensor (<NUM>) comprising an array (<NUM>) of pixels (62a, 62b, . . . <NUM>n), each pixel (<NUM>n) configured to generate an output and each pixel (<NUM>n) corresponding to a different position (<NUM>n) of the array (<NUM>) of positions (50a, 50b, . . . <NUM>n) of the cavity (<NUM>);
a human-machine interface (<NUM>) configured to provide an instruction (<NUM>) to a user (<NUM>); and
a controller (<NUM>) in communication with the infrared sensor (<NUM>) and the human-machine interface (<NUM>), the controller (<NUM>) configured:
(i) to determine a temperature at each position (<NUM>n) of the array (<NUM>) of positions (50a, 50b, . . . <NUM>n) of the cavity (<NUM>) as a function of the output of each pixel (<NUM>n) of the array (<NUM>) of pixels (62a,62b,...62n);
characterized in that the controller is further configured:
(ii) to recognize a rise and fall in the temperature at one or more positions (50a, 50b, . . . <NUM>n) of the array (<NUM>) of positions (50a, 50b, ... <NUM>n) within the cavity (<NUM>);
(iii) to estimate the position (50n) or positions (50a, 50b, . . . <NUM>n) of the array (<NUM>) of positions (50a, 50b, . . . <NUM>n) within the cavity (<NUM>) that the food item (<NUM>) occupies as a function of the one or more positions (50a, 50b, . . . <NUM>n) of the array (<NUM>) of positions (50a, 50b, . . . <NUM>n) within the cavity (<NUM>) where the controller (<NUM>) recognized a rise and fall in temperature occurred; and
(iv) to determine whether the position (<NUM>n) or positions (50a, 50b, . . . 50n) that the food item (<NUM>) is estimated to occupy is adequate for the controller (<NUM>) to determine accurately a temperature of the food item (<NUM>) during an automatic heating operation that utilizes the infrared sensor (<NUM>).