Infrared oven

Abstract

An infrared oven and method of toasting use a support configured to hold a food product relative to an infrared source. A light source and a camera are arranged relative to the support to illuminate the food product and capture digital images of the food product. A processor receives and analyzes successive images from the camera. The processor operates the IR source to achieve a predetermined toasting level of the food product. The processor operates the IR source to terminate operation of directing IR energy when the predetermined toasting level is reached.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 817,277 filed on March 12, 2019 and U.S. Patent Application No. 16 / 814,414 filed on March 10, 2020, the contents of which are incorporated herein by reference in their entirety. Technical Field Background Art

[0003] Many restaurants offer toast and toasted English muffins as regular menu items. Many other menu items include sandwiches that contain toasted baked goods including toasted bread slices, toasted fruit bread, toasted bagels or toasted English muffins.

[0004] Baking a food has a flavor that is noticeably different from the same food before baking. Baking a food also changes the color of the bread product and its texture. In addition to changing the flavor, color, and texture, the baking process often develops a pleasant aroma.

[0005] Baking of foods, such as sliced ​​bread, English muffins, bagels, pizza crust, and other baked foods, is typically accomplished using radiant or conductive energy transferred from one or more heat sources into the baked food. The process of baking (also referred to herein as browning) is the result of a chemical reaction known as the Maillard reaction. The Maillard reaction is a reaction between carbohydrates and proteins that occurs when heat is applied, which produces browning.

[0006] It is believed that when the Maillard reaction proceeds too far or for too long, the carbohydrates in the bread product will completely oxidize and form carbon. Carbon absorbs light. Therefore, the surface of a burnt bread product appears black. Therefore, the term "burning" is considered to be the heat-induced oxidation of carbohydrates to the extent that the carbon content of the surface of the bread product is high enough to absorb visible light impinging on the surface of the bread product, thus making the surface or part of the surface of the bread product appear black in color to an ordinary observer.

[0007] A well-known problem with all types of prior art ovens is that they are generally unable to consistently achieve uniform baking on the surface of a bread product in the same amount of time. Due to their mass, surface irregularities, and temperature, bread products such as English muffins are particularly difficult to uniformly and consistently bake in a short period of time because the peaks and valleys of the English muffin surface are at different distances from the IR source that achieves the baking process. Since many restaurant operators require and prefer to be able to bake bread products such as English muffins as quickly as possible, attempts to shorten baking times by simply increasing the input infrared energy typically result in more bread products being scorched rather than being baked. An oven and method for baking foods such as bread and English muffins that can consistently provide uniform browning in a relatively short period of time would be an improvement over the prior art. Summary of the invention

[0008] An example of an oven includes a support configured to hold food. An infrared (IR) source is arranged relative to the support. The IR source is operable to direct IR energy to the food on the support. A light source is arranged relative to the support. The light source is operable to illuminate the food on the support when the IR source is operated to direct the IR energy. A camera is operated to capture a digital image of the food on the support. A processor receives the image from the camera. The processor analyzes successive images received from the camera. Based on the analysis of the successive images, the IR source is operated to achieve a predetermined toasting level of the food. The processor operates the IR source to terminate the operation of directing the IR energy when the predetermined toasting level is reached.

[0009] In other examples of the oven, the light source operates to illuminate the support, and the processor analyzes the digital image from the camera to determine the presence of food on the support. The processor determines the current baking level of the food based on the amount of light in at least one test spectrum in each of the consecutive images received from the camera. The processor analyzes the digital image from the camera to determine the initial color of the food on the support, and the processor determines the weighted value of at least one test spectrum analyzed by the processor to determine the current baking of the food. The at least one test spectrum may include a green light test spectrum and a red light test spectrum. The weighted value of the red light test spectrum may increase as the darkness of the initial color of the food increases. The processor may further determine the current baking level of the food based on a brightness compensation factor of at least one test spectrum. The processor may calculate at least one brightness compensation factor based on a reference brightness of at least one test spectrum determined according to a portion of the initial image of the food acquired by the camera. The portion of the initial image may be a portion that does not include the food. At least one brightness compensation factor may be further calculated based on the current brightness of at least one test spectrum determined according to the same portion of a subsequent image from the camera.

[0010] Other examples of ovens may include an image tearing mask. The processor may apply the image tearing mask to each successive image received from the camera and pass or reject the image for determining the current toasting of the food product based on the application of the image tearing mask. The oven may include a predetermined static mask. The processor may apply the static mask to the images received from the camera to limit the portion of the received image that is analyzed to determine the current toasting of the food product. The oven may determine a dynamic mask based on at least one image of the food product received from the camera. The dynamic mask includes at least one calculated boundary of the food product in at least one image, and the processor applies the dynamic mask to the images received from the camera to limit the portion of the received image that is analyzed to determine the current toasting of the food product.

[0011] Additional examples of ovens may include an ejector operably connected to a support and a processor. When a predetermined toasting level is reached, the processor may operate the ejector to remove the bread product from the vicinity of the IR source. The oven may include an IR source configured as a ring, and the camera is positioned at the center of the IR source. The camera may include a wide angle lens. The camera may be recessed from the outer surface of the IR source in a direction away from the bread product. The light source may be positioned at the center of the IR source and adjacent to the camera. The oven may include a forced air source and a duct opened around the camera between the camera and the IR source to generate a forced air flow around the camera.

[0012] A method of toasting, exemplarily including holding a food on a support relative to an infrared (IR) source. Operating the IR source to direct IR energy to the food on the support. Illuminating the food on the support. Acquiring a digital image of the food on the support with a camera. Analyzing consecutive images acquired by the camera to determine a current toasting level of the food based on the amount of light in at least one test spectrum in each of the digital images acquired by the camera. Determining when the current toasting level of the food reaches a predetermined toasting level of the food. When the predetermined toasting level of the food is reached, operating the IR source to terminate directing IR energy to the food. The method may include determining an initial color of the food by analyzing an initial image from the camera, and determining a weighted value of at least one test spectrum based on the initial color to determine the current toasting level of the food. The method may further include determining a reference brightness of at least one test spectrum based on a portion of the initial image that does not include the food, determining a current brightness of at least one test spectrum based on the same portion of a subsequent image from the camera, calculating a brightness compensation factor of at least one test spectrum based on the reference brightness and the current brightness, and further using the brightness compensation factor of at least one test spectrum to calculate the current toasting level of the food. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a system diagram of an exemplary embodiment of an oven.

[0014] Figure 2 The toasting doneness levels are depicted exemplarily.

[0015] Figure 3 is a flow chart of an exemplary embodiment of a baking method.

[0016] Figure 4 An exemplary embodiment of an oven in a horizontal configuration is depicted.

[0017] Figure 5 This is a system diagram of a horizontally configured oven.

[0018] Figure 6 An exemplary embodiment of an oven in an angled configuration is depicted.

[0019] Figure 7 is along Figure 6 A cross-sectional view taken along line 7-7. DETAILED DESCRIPTION

[0020] Figure 1 An exemplary embodiment of an oven 10 is depicted. The oven 10 uses at least one infrared (IR) source 12, such as Figure 1 1. The IR sources 12 are illustratively depicted in FIG. 1. The IR sources may illustratively take the form of conductive coils that are believed to heat and emit IR energy when energized. It will be appreciated that there are other IR energy sources that may be used in other embodiments, including but not limited to one or more IR emitting LEDs, such as an array arrangement of IR emitting LEDs. The IR sources 12 are arranged to direct IR excitation 14 to the food 16. Figure 1 In the embodiment depicted in, and as will be explained in further detail herein, the IR source 12 can be configured and / or operated as a baking IR source 12A and a heating source 12B, the IR source 12 being illustratively an IR emitting source. Additional disclosure and description of an oven and its components and operation are provided in the applicant's co-pending U.S. Patent Application Publication No. 2019 / 0387926 entitled "Infrared Toaster", which is incorporated herein by reference in its entirety. Based on the present disclosure, it will be recognized that the features disclosed therein are combined with the features disclosed herein.

[0021] Figure 1The oven 10 of exemplarily presents an embodiment of a single side for baking food 16, and the baking surface 18 is arranged to be close to the baking IR source 12A. In this embodiment, the heating source 12B provides additional thermal energy to the baking system to increase the overall temperature of the baking system during operation. Once the food 16 is turned over in the oven 10, this embodiment can bake the second side of the food 16 by performing a second baking cycle on the food 16. In other embodiments, two baking IR sources 12A can be arranged in the oven 10 to bake the two surfaces of the food 16 at the same time. Although heat treatment, exemplary cooking, grilling, baking or baking can be achieved in other embodiments, the food is exemplarily a bread product that is desired to be baked. Bread products may include but are not limited to sliced ​​bread, English muffins, bagels, pizza and flatbreads, rolls or fruit bread. In other embodiments, a complete or partially complete sandwich or sandwich portion (e.g., a half-open sandwich) can be baked. In a further embodiment, the oven can be operated to melt the cheese placed on the bread product.

[0022] In an embodiment, baking IR source 12A is configured with one or more sensors as described herein, and the one or more sensors point to the baking surface to be baked by IR source. Baking IR source 12A is arranged to be close to the baking surface and operates with generally higher thermal energy output. This is compared with heating source 12B that can be a heating IR source but may not include associated sensors or at least the baking sensor described about baking IR source 12A. In addition, heating IR source 12B may not point to the baking surface and may also operate with generally lower thermal energy output. In an example, baking IR source 12A is configured to guide IR energy to the surface of food 16 exemplarily by radiant heat transfer, and heating source 12B may be configured to heat food 16 and the entire interior of the oven by radiation, conduction and / or convection heat transfer.

[0023] In an example, the baking IR source 12A may include a resistance coil exposed toward a baking surface 18 of the food 16, which generates IR excitation and directs the IR excitation to the baking surface 18. The heating source 12B may also include a resistance wire, but the food may be isolated from the resistance wire. In an example, a glass layer and a stainless steel layer may be inserted between the resistance wire and the food. This helps to disperse the heat from the resistance wire of the heating source 12B to increase the temperature inside the oven and increase the temperature of the food, but only provides limited or no food baking.

[0024] As previously mentioned, the challenge of baking equipment is to quickly provide a certain amount of energy to the food 16 to achieve the desired level of baking or amount of baking on the outside of the food without over-baking or under-baking within a narrow quality range. In addition, it is desirable to provide an apparatus and method for baking, wherein a specific level of baking is consistently achieved. In another exemplary embodiment, it is desirable to provide an apparatus and method for baking, wherein this specific level of baking is consistently achieved across a range of food types. Although foods, more specifically baked foods, differ in various physical properties, examples of different physical properties of baked foods include surface area (A), thickness (T), and initial color (C).

[0025] Figure 2 An example of different doneness levels on various examples of baked goods is provided. Figure 2 The examples provided in are arranged so that baked goods of the same type are oriented in horizontal rows, while the vertical rows each represent the level of toasting achieved on each type of baked good. Figure 2 An example of five different toasting levels is provided, but it should be appreciated that more or fewer levels may be used with different embodiments, and that the range between levels may be wider to include more toasting and less toasting.

[0026] Return to reference Figure 1 , oven 10 includes features that will be described in further detail herein, whereby the baking progress of food product 16 can be closely monitored and the operation of components of oven 10 can be controlled to quickly bake the food product to a desired level of baking, and to terminate the baking process so as not to exceed the desired level of baking.

[0027] Oven 10 includes at least one sensor, illustratively a camera 20, oriented relative to food product 16 and directed toward baking surface 18 of the food product. Figure 1 1, but more specific exemplary embodiments of such a camera arrangement will be disclosed in greater detail herein, and it will be appreciated that embodiments of oven 10 may include other features within camera 20 in addition to those provided in the examples herein. Camera 20 illustratively acquires digital image captures of the surface of the food being baked, and provides these digital image captures to processor 22 for analysis and control of IR source 12.

[0028] Figure 1A camera 20 is depicted that is arranged in the center of the baking IR source 12A and is pointed at the baking surface 18 of the food 16. Exemplarily, the baking IR source 12A is annular in shape, with the camera 20 positioned inside the baking IR source 12A. As will be described in further detail herein, it is desirable to protect the camera 20 from the heat from the IR source 12, and therefore, the camera 20 is recessed from the heating element 24 of the baking IR source 12A. However, as will be explained herein, it is desirable that the field of view 25 of the camera 20 is wide, so that the digital image captured by the camera 20 includes at least a large portion of the baking surface. Therefore, there is a limit to the distance that the camera 20 can be recessed relative to the baking IR source 12A. In some embodiments, the digital image can capture a field of view that extends beyond the periphery of the food, while in other embodiments, the digital image can capture a field of view that includes only a portion of the baking surface.

[0029] In order to perform accurate analysis of food baking, supplementary light is projected onto the baking surface 18. The supplementary light is provided by one or more light sources 26. The light source 26 is illustratively an LED light source, which is arranged close to the camera 20, such as at the center of the baking IR source 12A. In other embodiments, the light source 26 can be located at other positions, such as on the side of the oven 10; however, it has been found that increasing the relative angle of the normal of the light source 26 toward the baking surface 18 improves the illumination of the baking surface 18 by the light source 26. The light source 26 can be operated to emit visible spectrum light, IR spectrum light, UV spectrum light, or a specific wavelength or combination of wavelengths within these ranges according to the specific embodiments described herein. Exemplary and non-limiting embodiments can project green spectrum wavelengths of visible light, red spectrum wavelengths of visible light, IR spectrum wavelengths of light, or all visible spectrum wavelengths of light (e.g., white light).

[0030] As previously mentioned, it is desirable to protect the camera 20 from excessive heat generated by the heating element 24 of the baked IR source 12A. In addition, the inventors have recognized that the temperature of the light source 26 can change the intensity of the light generated, thereby causing detection errors, as will be discussed in further detail herein. In addition, it is desirable to limit the exposure of the light source 26 as a whole to excessive heat. An air source directs air flow around and through the light source 26 and the camera 20, and the air source can be a blower 28, but can also be other air movement sources recognized by those of ordinary skill in the art.

[0031] The air flowing past the camera 20 in the direction of the food item 16 also creates an air barrier around the lens of the camera 20 that protects the camera 20 from the accumulation of grease, condensation, food particles, dust, or other contaminants that could cloud or blur the images captured by the camera 20. However, this air flow may also have the negative effect of locally cooling the food item 16 at the location of the air flow. Therefore, an air plenum 30 configured around the camera 20 and light source 26 enables air to circulate relative to the camera and light source 26. This cools the camera 20 and light source 26, and heats the air that is directed past the camera 20 toward the food item 16. The air plenum 30 also exhausts a portion of the circulating air out of the air plenum 30, away from the food item 16.

[0032] The food support 32 supports the food 16 between the IR sources 12. Embodiments of the food support 32 may take a variety of forms as will be described in further detail herein, and may be operated in such a form to facilitate loading and ejecting the food 16 relative to the oven 10. The food support 32 holds the food 16 within the oven 10 in a predetermined position relative to at least the camera 20 and the baking heat source 12A. The food support 32 may be, but is not limited to, a grate bar, a door, a platform, or a conveyor belt. As will be described in further detail herein, the ejector 34 may be further operated by the processor 22 to facilitate mechanical ejection of the food so as to quickly end the baking process.

[0033] The processor 22 is communicatively connected to a computer readable medium (CRM) 36, which is illustratively non-transitory and on which is stored computer readable code in the form of a computer program or software that, when executed by the processor 22, causes the processor to operate in a manner that performs functions and actions as described in further detail herein. It will be appreciated that the processor 22 is illustratively incorporated into any of a variety of known controller circuits, integrated circuits, microcontrollers, or associated circuits. The processor 22 may be part of a central processing unit (CPU) including integrated memory, but in embodiments, the CRM 36 may be a separate component or communicatively connected to the processor 22. The processor 22 accesses software or firmware in the form of computer readable code stored on the CRM 36 as an integrated memory or an external memory. The processor 22 executes the computer readable code as a set of instructions to perform the functions described herein, including receiving inputs, calculations, and outputs as will be described. Processor 22 receives the digital images captured by camera 20 and uses image processing techniques as described in further detail herein to monitor the toasting process and provide operating commands to components of oven 10 in a manner that achieves a desired level of toasting of food product 16 .

[0034] The processor can also be communicatively connected to the source of model or algorithm 38, which can be stored on a non-transitory computer-readable medium, and such a model can define parameters or algorithms for the baking operation of a specific type of food or a specific request to be baked. This article provides an example of an equation that can be used during the operation process, and such an equation can be stored on a non-transitory computer-readable medium. Model 38 can include various baking level models, which can be represented as a curve of a determined amount of reflected light from food, and the curve represents different baking levels. Model 38 can be stored in processor and oven 10 locally, or can be stored in a remote location, and communication connection can span a local area network or a wide area network. As will be further explained in detail herein, processor 22 can be selected from the information stored in the source of model 38 when receiving input or detecting a specific condition. It will be recognized that this can also be stored on CRM 36.

[0035] The oven 10 may include a user interface 40 through which the oven 10 receives one or more user inputs to control the toasting operation. In an exemplary embodiment, the user interface 40 may be a physical button or may be a touch-enabled graphical display. In further embodiments, the user interface may be presented on a personal computing device that is communicatively connected to the oven 10, for example, via a Wi-Fi or Bluetooth communication protocol. Examples of inputs that may be received include 1-side or 2-side toasting; identification of the food item and the desired toasting level.

[0036] In another embodiment, the processor 22 of the oven 10 can be communicatively connected to a kitchen management system (KMS) 42, which can be exemplarily a computer system implemented locally or remotely, which operates to manage customer orders, order completion status, monitor inventory levels and operation of equipment in the kitchen, and / or provide operating instructions to equipment in the kitchen. In an exemplary embodiment, the communication connection between the processor 22 and the KMS 42 can enable the KMS to provide operating instructions to the processor 22, such as the type of food to be baked, the side of the food to be baked, and the baking level to be achieved, without further input from the user or staff. Although not depicted, a food dispenser (e.g., a baked food dispenser) can be operably connected to the oven 10 and communicatively connected to the KMS, and the coordinated operation between the devices can cause the oven 10 to automatically load the appropriate baked food and operate the oven 10 to achieve the desired baking level of the baked food.

[0037] Figure 3 is a flow chart depicting an exemplary embodiment of a method 100 for baking a food product and will be described herein, for example, with reference to the above description of Figure 1The present invention relates to an oven 10 and an exemplary embodiment of a food product of a baked food described in the present invention. Method 100 begins by receiving bread into an oven at 102. In addition, the oven receives the desired toasting level of the bread. For example, when the oven is configured to provide the same toasting level in each baking operation, this can be a preset toasting level. Or, the desired toasting level can be input by a user or received from a KMS as described above. In a further exemplary embodiment, the received slice of bread can be identified, and the specific identification of the bread (for example, white bread, wheat bread, rye bread, bagel, English muffin or fruit bread) can have a preset associated toasting level. The toasting level can be defined as one or more curves or functions of the determined light quantity as described in further detail herein.

[0038] At 104, the oven illuminates the baking chamber with red light. The system determines whether the food has been loaded into the oven. The inventor has found that red spectrum light is useful for determining whether the baking chamber is empty or whether baked food has been received for baking, because red light provides a contrast between the food and the interior of the oven in a wide range of food types, shapes and initial colors. If the identification of the baked food has not yet been received, the system can determine the initial color of the baked food at 106. In doing so, the bread is illuminated at 106, and the image of the illuminated bread is captured, and the initial color of the bread is determined at 106. In some embodiments, this lighting can be used with white light or a subset of the visible spectrum can be used for lighting purposes. In one embodiment, red light illumination can be used for the contrast between the different initial colors of the available bread. In some embodiments, the red spectrum of light can be useful for both light and dark bread, and also helps the system to distinguish the presence of bread in the oven and an empty oven.

[0039] When used to evaluate the progress of baking and the level of baking, different spectra may be preferred or produce preferred results based on the initial color of the food. In an example, a combination of one or more of green spectrum light, blue spectrum light and red spectrum light may be used for baking analysis. In another example, analysis of green spectrum light and red spectrum light may be used. At 108, a weighted value for each of the test spectra is determined. In an example, weighting may be a function of the determined initial color of the food. The initial color of the food may be standardized based on the expected range of the initial color of the food. The initial color of the determined food may be compared with one or more thresholds associated with different weighted values. In another example, the weighted value for each of the light test spectra is determined by a function. It will be appreciated that a weight of 0.0 may have the effect of a test spectrum not used in determining. It will also be appreciated that weighting may have the effect of determining using only a single test spectrum. Generally, it has been determined that the red light test spectrum is advantageous for determining the baking of a food (e.g., dark rye) with a darker initial color, while the green light test spectrum is advantageous for determining the baking of a food (e.g., white bread) with a lighter initial color.

[0040] As will be described in further detail herein, the toasting determination may be calculated based in part on the following equation, where the parameter W G , W B and W R are the respective weights applied to each of the green, blue, and red test spectra.

[0041] Equation 1: R DN =(W G (RB BG -[CB BG *BF NBG ])+W B (RB BB -[CB BB *BF NBB ])+W R (RB BR -[CB BR *BF NBR ]))*MC

[0042] in:

[0043] MC = mask compensation factor;

[0044] BF NBG = Brightness factor of non-bread green;

[0045] BF NBB = Brightness factor of non-bread blue;

[0046] BF NBR = Brightness factor of non-bread red;

[0047] RB NBR = reference brightness of non-bread red;

[0048] RB BR = Reference brightness of bread red;

[0049] RB BG = Reference brightness of bread green;

[0050] RB BB = Reference brightness of bread blue;

[0051] CB BR = the current brightness of bread red;

[0052] CB BG = Current brightness of breadgreen;

[0053] CB BB =Current brightness of bread blue;

[0054] R DN = Original doneness value.

[0055] Returning to 110, after the bread is identified, at 110, the bread can be illuminated with white light. White light is used to assess the toasting level during the baking process. It will be appreciated that in embodiments where white light (or the same spectrum) is used to illuminate the food to determine the initial color of the food at 106, 106 and 110 can be effectively combined. This is also true for other examples, where the same spectrum is used to illuminate the food for initial color determination and monitoring the progress of baking. As described above, it will be appreciated that in other embodiments, alternative colors or combinations of illumination light wavelengths or one or more colors alone can be used, including but not limited to the illumination of light using green spectrum wavelengths. Although test spectra in red, green and / or blue wavelengths are described in the examples herein. It should be appreciated that in other embodiments, other selected test wavelength spectra can be used, including but not limited to yellow, orange, purple, infrared or UV spectra. In the example, these test wavelength spectra and different combinations of identified baked foods can be used to analyze specifically identified baked foods for baking, or such different combinations can be used to analyze baked foods with specific properties. As previously described, the use of specific test spectrum wavelengths may be adjusted using weightings of the various test spectra based on the identification of the baked good or the identification of the nature of the baked good.

[0056] At 112, a heat source is activated. As described above, the heat source may illustratively be a coil that is heated to a luminescent temperature upon receiving electrical excitation, at which temperature the coil emits IR radiation toward the bread held in the oven. As previously described, in embodiments of the oven, the oven may be configured to toast a single side of a received bread, and a heat source on a side of the bread opposite the toasting side of the bread may be used to increase the ambient temperature of the oven while not operating to achieve a particular toasting level on a side of the bread opposite the toasting side.

[0057] The method enters a baking level assessment subprocess 114, which is repeated until it is determined that the bread has been baked to the desired baking level. The subprocess 114 begins at 116, where a digital image of the bread is acquired with a camera. The acquisition of the digital image at 116 may further include IR filtering. IR filtering may be physically performed with the IR lens of the camera, or may be performed digitally during the image acquisition process of the camera. In either case, the digital image acquired at 116 is a digital image of the received bread depicted in an oven without emitting IR excitation from a heat source. Illumination of the baking surface from 110, for example, by white light also helps to acquire the image, and supplementary light saturates the effect of the light emitted from the heat source.

[0058] At 118, an image mask is acquired. In an example, a static or default image mask may be stored locally to the processor of the oven. The static image mask may be the same mask for all foods, or different static masks may be stored for different types of foods (e.g., English muffins, bagels, bread slices, fruit bread). If the identification of the food is known, the corresponding static mask may be selected and used. In yet another example, a dynamic image mask may be created based on the image acquired at 116. In an example, such a dynamic image mask may be created by modifying the static image mask as described above. Once a dynamic image mask is created, in an example, the dynamic image mask may be used throughout the toast determination process, while in other examples, the dynamic mask may be iteratively updated during subsequent cycles of the imaging process. The image mask may exemplarily exclude all portions of the digital image that are not a portion of the food, and the image mask limits the portion of the digital image data that is evaluated to determine the toast level of the bread.

[0059] In an example, the doneness value calculated according to Equation 1 above may be created with respect to a static mask that determines the portion / region of the digital image data that is evaluated when determining the doneness value. Therefore, if a dynamic mask is used, which results in different regions of the digital image data being used, a mask compensation factor MC may be required to maintain an accurate determination. The mask compensation factor may be calculated first using a static mask and then using a dynamic mask based on spectral measurements from the digital image:

[0060] Equation 2:

[0061] in:

[0062] SMA R = average red value of static mask;

[0063] SMA G = average green value of static mask;

[0064] SMA B = average blue value of static mask;

[0065] DMA R = Dynamic mask average red value;

[0066] DMA G = Dynamic mask average green value;

[0067] DMA B = Dynamically mask the average blue value.

[0068] At 124, the current toasting level of the surface of the food is determined based on the amount of light reflected from the toasting surface and captured in the digital image from the camera. The image mask focuses the analysis to the portion of the acquired digital image that produces the most information related to the toasting level determination. As previously described, not all spectra returned in the digital image can be used, and some spectra can be more or less weighted than other spectra. In addition, the acquired digital image is evaluated using the image tear mask at 126, which blocks the portion of the acquired digital image that belongs to the bread and compares the non-bread portion of the image with the previous image to determine whether the image represents a discontinuity between images caused by movement of the bread in the oven or image acquisition errors by the camera. The image tear mask evaluation returns instructions that indicate whether to discard the acquired digital image in the loop of process 114 or use the image in process 114.

[0069] If this image is to be used, then an original doneness value is calculated, for example, using a weighted determination of the amount of light at the test spectrum according to equation 1 above. Looking further at equation 1, from the initial digital image, the bread is obtained at each test spectrum RB BX These reference brightnesses are used for each iteration of the calculation of the raw doneness value. For each subsequently acquired digital image accepted by the image tear mask evaluation at 126, the bread is obtained from the acquired image at each test spectrum CB BXAs will be explained in further detail herein, the temperature within the oven, and in particular the temperature of the light source within the oven, can change the light intensity output from the light source. This is corrected in the raw doneness value calculated using Equation 1, which includes the brightness correction factor BF for the light source for each of the test spectra. NBX .

[0070] In an example, the raw doneness value may be used as the current level of doneness of the food determined at 124 from the amount of light determined at one or more test spectra, or weighted test spectra, according to Equation 1. In other examples, the raw doneness value may be converted to the current level of doneness, illustratively by applying a function of the following form:

[0071] Equation 3: F DN =fn([R DN ])

[0072] The function used to determine the final doneness value may illustratively be linear, exponential or logarithmic to the raw doneness value and place the raw doneness value on the same scale as the roast level model or definition.

[0073] At 128, the converted toasting level is compared with the received desired toasting level value, and a determination is made as to whether toasting is complete. If the toasting process is complete and the desired toasting level value is reached, at 130, the oven operates to discharge the bread from the oven to quickly end the toasting operation so as not to excessively shoot the desired toasting level or burn the toasted bread.

[0074] If the desired toastiness level has not been reached, the subprocess 114 is repeated by acquiring a new digital image 116 and repeating the evaluation steps described herein. In an exemplary embodiment, one cycle of the subprocess 114 is performed every 250 milliseconds, although it will be appreciated that in alternative embodiments, the cycle between digital image acquisition and evaluation may be longer or shorter while remaining within the scope of the present disclosure. The subprocess 114 is thus repeated until it is determined that the desired toastiness level of the bread has been reached and the bread is discharged from the oven.

[0075] Optionally, at 132, a dynamic boundary mask is calculated to evaluate any changes in the surface area of ​​the baking surface due to the baking operation by comparing the current digital image to a previously acquired digital image and evaluating the changes in pixel values ​​between the two images. As previously described, some embodiments may use a standardized static image mask, may calculate a dynamic mask that is used throughout the baking process, or may update the image mask during the baking process. If areas of the bread have shrunk, these shrunk portions will appear as areas of large change within the image that exceed any abnormal amount of change due to baking between any two subsequently acquired images. At 118, the areas of change due to bread shrinkage are added to the updated dynamic mask to provide a dynamic mask that accounts for this possibility of bread shrinkage.

[0076] It will be appreciated that embodiments of method 100 may include more or fewer steps than those presented and described above. In addition to the method features described above, additional control processes may be implemented within method 100 to further refine and / or control the results of the process, as will be described in further detail herein.

[0077] In an exemplary embodiment, the process includes initialization and a heating dwell time between starting the heat source and acquiring the first digital image. In an exemplary embodiment, a dwell time between four and five seconds is used for toasting assessment before acquiring an initial reference image of the bread. In an embodiment, one or more scales or relationships may be used to assess the determined return light relative to the current toasting level. In an exemplary embodiment, two or more scales or relationships may be used to represent a range of toasting levels. In one embodiment, each toasting level has a separate function defining the return light and toasting level, while in other embodiments, one function may represent a progression between two or more toasting levels (e.g., light and medium toasting levels), while at least one other function is used to represent a progression toward one or more other toasting levels (e.g., dark toasting levels).

[0078] As previously discussed, heat from a heat source may affect the intensity of the light produced by the light source. These changes in light intensity may be recorded in the image processing as additional baking or slowed baking. In an exemplary embodiment, an additional camera may be added to the oven and pointed at the light source or a middle portion of the oven, such as insulation or other structure on the wall between the light source and the heating element. The readings from this camera or light sensor provide a reading or measurement of the light output intensity from the light source. The measurement of light intensity may be used as a compensation factor to ensure a consistent assessment of the baking level regardless of fluctuations in the output light intensity of the light source. For each light source / test spectrum, the brightness compensation factor BF NBX Exemplarily calculated as:

[0079] Equation 4:

[0080] In the calculation of the brightness compensation factor, the initial digital image is used to calculate the reference brightness RB at each test spectrum. NBX This is done illustratively by using one or more portions of the initial digital image known not to include the food product. In an example, the portion may include an area that is otherwise obscured by the image mask when assessing the toastiness of the food product. The brightness compensation factor is the difference between the reference brightness of the current digital image and the current brightness CB obtained. NBX The current brightness is calculated for each test spectrum and using the same one or more portions of the current digital image as used in the initial digital image. In the example of using a brightness compensation factor as described above, the compensation factor can also adjust the maturity value determination to maintain accuracy in the event of an error in the operation of one of the light sources, such as one of the light sources burning out or malfunctioning and not operating properly.

[0081] As described above, some examples of oven 10 may include a heating source 12B that is arranged to provide additional thermal energy to the baking system while providing little or no baking of the food itself. In an example, heat source 12B may include a resistance wire. The resistance of the resistance wire and therefore the current passing through the resistance wire may change with the temperature of the resistance wire. Therefore, an ammeter or other current sensor may be used to determine the temperature of heat source 12B, and heat source 12B may be operated to a set point temperature or within a set temperature range. In addition, control of the lower heater temperature may be based on the following equation:

[0082] Equation 5:

[0083] in:

[0084] T LH =Lower heater temperature;

[0085] TT LH =Lower heater target temperature;

[0086] t I = idle time in seconds;

[0087] t t = time since the last measurement.

[0088] In another exemplary embodiment of the method, one or more alternate processes provide additional calculations of toasting completion, and the results may indicate that the bread is at risk of being burnt or over-baked, thereby causing the bread to be discharged from the overload in the oven. One such alternate process is a "forward push" algorithm that compares changes in the doneness level between subsequent evaluation cycles. In an exemplary embodiment, the moving average of the change in the doneness level (e.g., over five previous evaluation cycles) must remain positive in order for the toasting process to continue. Conceptually, the toasting process is expected to accelerate until a saturation point (e.g., burnt), at which point the rate of change in the doneness level will stabilize or become negative. Therefore, as long as the toasting process follows the expected logarithmic pattern, the toasting process is allowed to continue.

[0089] In another exemplary embodiment, the latent heat model is used to perform an alternative calculation of the toasting level that is independent of the digital image acquired by the camera. Therefore, in the event of an image acquisition error by the camera, an image processing error, or a failure of the camera and / or light source required for image acquisition, the latent heat model backup method can provide control of the toasting operation. In a further embodiment, in the event that one or more errors prevent control based on the above-mentioned digital image acquisition, the oven can be operated in a latent heat control mode. In latent heat control, the system energy can be exemplarily represented by the following equation:

[0090] Equation 6:

[0091] Among them, T t = baking time in seconds.

[0092] In latent heat model control, the baking time is adjusted according to the latent heat stored in the oven. This is calculated by tracking how much energy has been input into the baking system from the heating cycle and how much energy has been lost based on the assumed baking system cooling curve. In such an embodiment, the expected baking time is calculated based on the expected baking level and the heat already in the baking system and the thermal energy being input into the oven during the baking operation. If the expected baking time is exceeded, or a predetermined threshold percentage is exceeded, or a threshold percentage based on the expected baking level, the system can ignore the baking process and discharge the bread to prevent the bread from being overbaked or burnt. Latent heat control is described in more detail in the applicant's pending U.S. patent application No. 16 / 556,826 entitled "Latent Heat Toaster Control", the entire contents of which are incorporated herein by reference.

[0093] Figure 4 An exemplary embodiment of oven 10 is depicted that is oriented horizontally. Figure 5A schematic diagram of the oven 10 in a horizontal orientation is also shown. It will be appreciated that these figures are similar to Figure 1 The same reference numerals between are used to indicate the same parts and incorporate the description of those parts as previously provided herein. It will be appreciated that in addition to other disclosures as provided in this application, additional embodiments may be described above with respect to Figure 1 Those features described herein are similar to those described herein Figure 4 and Figure 5 The features described are combined to arrive at embodiments within the scope of the present disclosure.

[0094] Figure 4 and Figure 5 The oven 10 depicted in FIG. 1 illustratively includes at least one conveyor belt 44. Figure 4 As shown, oven 10 may include two conveyor belts 44 that operate parallel to each other. These conveyor belts 44 may extend through oven 10. Conveyor belts 44 may be operated to advance food products (not shown) to predetermined locations within oven 10 relative to the aforementioned IR sources contained within oven 10. It should be appreciated that each conveyor belt may have at least one associated IR source within oven 10.

[0095] Figure 5 Examples of additional features that may be found in examples of oven 10 are provided. Figure 5 The conveyor 44 in the oven 10 operates only to transport food products into the oven 10, and the conveyor 44 may include dividers 46 extending outwardly from the conveyor 44, which help define spacing to retain food products thereon and help provide regular spacing and / or order for the food products 16 placed thereon.

[0096] The oven 10 may include a safety door 48 for a variety of purposes. In the first purpose, the safety door prevents a user from entering the baking area 50 relative to the IR source 12. This protects the user so that when the safety door 48 is closed, a corresponding limit switch 52 is activated, allowing the IR source 12 to be activated and heated. When the safety door 48 is open, the limit switch 52 is also open and prevents the IR source 12 from being energized.

[0097] In addition, if Figure 5 As shown, in the event that a food item 16 is misplaced on conveyor belt 44, the misplaced food item 16 may engage the exterior of safety gate 48, thereby preventing further advancement of the food item 16 despite advancement of conveyor belt 44. Further advancement of conveyor belt 44 will advance conveyor belt 44 relative to the misplaced food item 16 until the food item 16 is properly aligned with both conveyor belt 44 and safety gate 48 so as to be received into toasting area 50 during the next toasting operation.

[0098] exist Figure 5In the example shown, the toasting zone 50 is further defined by a bottom heater or tray 54 that supports the food within the toasting zone 50 relative to the IR source 12. When it is determined that the desired level of toasting has been achieved in the food, the bottom heater and / or tray 54 pivots or otherwise opens to release the toasted food 16 onto an exit ramp 56 for dispensing from the oven 10. Figure 4 and Figure 5 The examples depicted and described above may illustratively have the functional advantage of returning a baked food product to a position similar to the position in which the food product was first placed in the oven, and in the same orientation as the food product was loaded into oven 10 (e.g., with the baking surface facing upward).

[0099] Figure 6 and Figure 7 Yet another exemplary embodiment of oven 10 is depicted, wherein oven 10 is arranged in a tilted orientation. Figure 6 The oven 10 of this embodiment is depicted, and Figure 7 is along Figure 6 A cross-sectional view of line 7-7. Figure 4 and Figure 5 As with the embodiments shown, it will be appreciated that like reference numerals in these figures denote like components between the embodiments, and that for other exemplary embodiments of ovens within the scope of the present disclosure, Figure 6 and Figure 7 Some or all of the features described in the embodiments of the present invention may be used in combination with the features described above or herein.

[0100] like Figure 7 As best shown in FIG. 4 , the baking area 50 and many operating components of the oven 10 are arranged at an angle. In this embodiment, the user can insert food directly into the opening 60 that is selectively blocked by the safety door 48. The heating area 50 inside the opening 60 is also arranged at an angle and is defined by the baking IR source 12a and the heating IR source 12b. The heating IR source 12b also forms a bottom tray 54. The feed rack 58 is exposed at the inner end of the baking area 50 and is used to receive food in the baking area 50 and help align the food relative to the baking IR source 12a and the heating IR source 12b for consistent and repeated baking. When the baking operation is completed, the bottom tray 54 including the heating IR source 12b slides in the direction of arrow 62 inside the oven 10 to remove the tray 54 from the baked food. The baked food falls from the baking area 50 onto the exit ramp 56 to separate from the oven 10.

[0101] Many references are cited herein. The cited references are incorporated herein by reference in their entirety. In the event of inconsistency between the definition of a term in the specification and the definition of the term in the cited reference, the term should be interpreted based on the definition in the specification.

[0102] In the above description, certain terms are used for brevity, clarity and understanding. No unnecessary limitations beyond the requirements of the prior art should be inferred therefrom, because these terms are used for descriptive purposes and are intended to be broadly interpreted. The different systems and method steps described herein may be used alone or in combination with other systems and methods. It is contemplated that various equivalents, substitutes and modifications are possible within the scope of the appended claims.

[0103] The functional block diagrams, operation sequences, and flow charts provided in the accompanying drawings represent exemplary architectures, environments, and methods for performing novel aspects of the present disclosure. Although the methods included herein may be in the form of functional diagrams, operation sequences, or flow charts and may be described as a series of actions for simplicity of description, it should be understood and appreciated that these methods are not limited by the order of the actions because, according to these methods, some actions may occur in a different order than shown and described herein and / or occur simultaneously with other actions. For example, those skilled in the art will appreciate and appreciate that the methods may be alternatively represented as a series of interrelated states or events such as in a state diagram. In addition, not all actions shown in the methods are required for novel implementations.

[0104] This written description uses examples to disclose the invention, including the best mode, and also to enable those skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. If these other examples have structural elements that do not differ from the literal language of the claims, or if these other examples include equivalent structural elements that are not substantially different from the literal language of the claims, then these other examples are intended to be within the scope of the claims.

Claims

1. An oven, comprising: a support configured to hold a food product; an infrared (IR) source disposed relative to the support and operable to direct IR energy toward the food product on the support; a light source disposed relative to the support and operable to illuminate the food product on the support when the IR source is operated to direct IR energy; a camera operative to capture a digital image of the food product on the support while an IR source operative to direct IR energy toward the food product; a processor that receives the digital image from the camera, the processor analyzing successive images received from the camera and, based on the analysis, operating the IR source to achieve a predetermined level of toasting of the food product, wherein the processor operates the IR source to terminate operation of directing IR energy when the predetermined level of toasting is reached; wherein the processor determines, based on the continuous images received from the camera, a current toasting level of the food based on an amount of light in at least one test spectrum in each of the continuous images, the at least one test spectrum comprising a green light test spectrum and a red light test spectrum; wherein the processor analyzes the digital image from the camera to determine an initial color of the food on the support, and the processor determines a weighted value of the at least one test spectrum analyzed by the processor to determine a current toasting of the food, wherein the weighted value of the red light test spectrum increases as the darkness of the initial color of the food increases.

2. The oven according to claim 1, wherein: The light source operates to illuminate the support, and the processor analyzes the digital image from the camera to determine the presence of the food product on the support.

3. The oven of claim 1 further comprising an ejector operably connected to the support and the processor, wherein: When the predetermined toasting level is reached, the processor operates the ejector to remove the food product from the vicinity of the IR source.

4. The oven according to claim 1, wherein: The IR source is configured in a ring shape, and the camera is positioned at the center of the IR source.

5. The oven according to claim 4, wherein: The camera includes a wide-angle lens.

6. The oven according to claim 5, wherein: The camera is recessed from an outer surface of the IR source in a direction away from the food product.

7. The oven according to claim 4, wherein: The light source is positioned centrally of the IR source and adjacent to the camera.

8. The oven of any one of claims 1-7, further comprising a forced air source and a duct, the duct opening around the camera between the camera and the IR source to create a forced airflow around the camera.

9. An oven, comprising: a support configured to hold a food product; an infrared (IR) source disposed relative to the support and operable to direct IR energy toward the food product on the support; a light source disposed relative to the support and operable to illuminate the food product on the support when the IR source is operated to direct IR energy; a camera operative to capture a digital image of the food product on the support while an IR source operative to direct IR energy toward the food product; a processor that receives the digital image from the camera, the processor analyzing successive images received from the camera and, based on the analysis, operating the IR source to achieve a predetermined level of toasting of the food product, wherein the processor operates the IR source to terminate operation of directing IR energy when the predetermined level of toasting is reached; The processor determines the current toasting level of the food according to the continuous images received from the camera based on the amount of light in at least one test spectrum in each of the continuous images and a brightness compensation factor of at least one test spectrum.

10. The oven according to claim 9, wherein: The processor calculates the at least one brightness compensation factor based on a reference brightness of at least one test spectrum determined based on a portion of an initial image of the food acquired by the camera, wherein the portion does not include the food, and the at least one brightness compensation factor is also calculated based on a current brightness of at least one test spectrum determined based on the same portion of subsequent images from the camera.

11. An oven, comprising: a support configured to hold a food product; an infrared (IR) source disposed relative to the support and operable to direct IR energy toward the food product on the support; a light source disposed relative to the support and operable to illuminate the food product on the support when the IR source is operated to direct IR energy; a camera operative to capture a digital image of the food product on the support while an IR source operative to direct IR energy toward the food product; a processor that receives the digital image from the camera, the processor analyzing successive images received from the camera and, based on the analysis, operating the IR source to achieve a predetermined level of toasting of the food product, wherein the processor operates the IR source to terminate operation of directing IR energy when the predetermined level of toasting is reached; wherein the processor applies an image tearing mask to each successive image received from the camera and passes or rejects the successive images for use in determining a current toasting of the food product based on the application of the image tearing mask.

12. An oven, comprising: a support configured to hold a food product; an infrared (IR) source disposed relative to the support and operable to direct IR energy toward the food product on the support; a light source disposed relative to the support and operable to illuminate the food product on the support when the IR source is operated to direct IR energy; a camera operative to capture a digital image of the food product on the support while an IR source operative to direct IR energy toward the food product; a processor that receives the digital image from the camera, the processor analyzing successive images received from the camera and, based on the analysis, operating the IR source to achieve a predetermined level of toasting of the food product, wherein the processor operates the IR source to terminate operation of directing IR energy when the predetermined level of toasting is reached; wherein the processor applies a predetermined static mask to the image received from the camera to limit a portion of the received image that is analyzed to determine the current toasting of the food product.

13. An oven, comprising: a support configured to hold a food product; an infrared (IR) source disposed relative to the support and operable to direct IR energy toward the food product on the support; a light source disposed relative to the support and operable to illuminate the food product on the support when the IR source is operated to direct IR energy; a camera operative to capture a digital image of the food product on the support while an IR source operative to direct IR energy toward the food product; a processor that receives the digital image from the camera, the processor analyzing successive images received from the camera and, based on the analysis, operating the IR source to achieve a predetermined level of toasting of the food product, wherein the processor operates the IR source to terminate operation of directing IR energy when the predetermined level of toasting is reached; wherein the processor further determines a dynamic mask based on at least one image of the food product received from the camera, wherein the dynamic mask includes at least one calculated boundary of the food product in the at least one image, and the processor applies the dynamic mask to the image received from the camera to limit the portion of the received image that is analyzed to determine the current toasting of the food product.

14. A method for baking using the oven according to any one of claims 1 to 13, the method comprising: holding the food on a support relative to the IR source; operating the IR source to direct IR energy toward the food product on the support; illuminating the food on the support; acquiring a digital image of the food product on the support with a camera while an IR source operates to direct IR energy toward the food product; analyzing successive images acquired by the camera to determine a current toasting level of the food product based on an amount of light in at least one test spectrum in each of the digital images acquired by the camera; determining when a current toasting level of the food product reaches a predetermined toasting level of the food product; operating the IR source to terminate directing IR energy to the food product when the predetermined toasting level of the food product is reached; determining an initial color of the food product by analyzing an initial image from the camera; determining a weighted value of the at least one test spectrum based on the initial color to determine the current toasting level of the food product; determining a reference brightness of at least one test spectrum based on a portion of the initial image that does not include the food; determining a current brightness of at least one test spectrum based on the same portion of a subsequent image from the camera; Calculate a brightness compensation factor of at least one test spectrum according to the reference brightness and the current brightness; as well as The brightness compensation factor of at least one test spectrum is further used to calculate the current toastiness level of the food product.

Images