Abstract:
A method for cooking food items in an oven is disclosed. A history of instant oven temperatures is initially obtained during a cook of a first food item. A salient representation of the oven temperature history is stored in a non-volatile memory. The salient representation includes multiple average oven temperatures, each selected to represent a summary of the instant oven temperatures at various specific time periods throughout the cook of the first food item. During a cook of a second food item that is substantially similar to the first cook item, the current cook settings are dynamically adjusted during the cook of the second food item based on the results of a comparison between the instant oven temperatures and the stored average oven temperatures in order to duplicate the result of the cook of the first item.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. application Ser. No. 13/367,164, filed on Feb. 6, 2012, the entire content of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to ovens in general, and in particular to a method for cooking food in an oven. 
     2. Description of Related Art 
     Conventional ovens generally use a temperature feedback mechanism to maintain oven temperature relatively constant at a set temperature. The temperature feedback mechanism turns on the heating source when the oven temperature is less than the set temperature, and turns off the heating source when the oven temperature is greater than the set temperature. Basically, the only information that matters is the oven temperature, and the only action taken based on the oven temperature information is to turn the heating source on or off in order to maintain the oven temperature as close to the set temperature as possible. 
     Once the oven temperature of an oven has reached a steady state (i.e., the set temperature), a user can at any time put a food item into the oven. The amount of time the food item should be in the oven may be determined by the internal temperature at which the food item has reached. Once the food item has reached a predetermined internal temperature, the food item is considered to be “done.” In other words, for conventional ovens, once the oven has achieved the set temperature, the only other variable is time. A food item is considered to be done when it has been placed in the oven operating at the proper set temperature for the desired amount of time. 
     Rapid-cook ovens operate almost entirely based on time. Once a rapid-cook oven has reached its set temperature, for example, if a user pushes a button on a user interface that says “pepperoni pizza,” a set of previously entered cooking instructions that correspond to that selected food item are executed. Those cooking instructions may include: cook food item with a microwave on 50% power and a blower on 100% power for 1.5 minutes, and then continue to cook food item with the microwave on 100% power and the blower on 80% power for another 3 minutes. At the end of the 4.5 minute period, the cooking of the food item is deemed to have been completed because the allotted cooking time at the desired temperature and cook profile conditions have been met. 
     The present invention provides an improved method for cooking food items in an oven. 
     SUMMARY OF THE INVENTION 
     In accordance with a preferred embodiment of the present invention, a history of instant oven temperatures is initially obtained during a cook of a first food item. A salient representation of the oven temperature history is stored in a non-volatile memory. The salient representation includes multiple average oven temperatures, each selected to represent a summary of the instant oven temperatures at various specific time periods throughout the cook of the first food item. During a cook of a second food item that is substantially similar to the first cook item, a set of instant oven temperatures is obtained at the same various specific time periods during the cooking of the first cook item, and the current cook settings are dynamically adjusted during the cook of the second food item based on the results of a comparison between the obtained instant oven temperatures and the stored average oven temperatures in order to duplicate the result of the cook of the first item. 
     All features and advantages of the present invention will become apparent in the following detailed written description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention itself, as well as a preferred mode of use, further objects, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a front view of an oven in which a preferred embodiment of the present invention can be incorporated; 
         FIG. 2  is a flowchart of a method for developing a cook setting for a food item during a cook_setting_development mode of the oven from  FIG. 1 , in accordance with a preferred embodiment of the present invention; and 
         FIG. 3  is a flowchart of a method for cooking a food item using a cook setting during a cook_with_setting mode of the oven from  FIG. 1 , in accordance with a preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring now to the drawings and in particular to  FIG. 1 , there is depicted a front view of an oven in which a preferred embodiment of the present invention may be incorporated. As shown, an oven  10  is defined by a housing  11  having a cavity  12 . Oven  10  includes a heating and airflow system (not shown) to supply heat to cavity  12  for heating up any food items that have been placed inside cavity  12 . 
     Oven  10  also includes a user interface panel  15 . User interface panel  15  is preferably implemented with touchscreens but they can also be implemented with keypads and liquid crystal displays. A user can enter commands, such as cooking temperature within cavity  12 , cooking time, blower speed, microwave, steam amount, etc., via user interface panel  15  to effectuate cooking controls on any food items placed within cavity  12 . In addition, oven  10  includes various electronic devices (not shown), such as a controller, volatile memories, and non-volatile memories, for providing various functions related to oven operations. 
     In accordance with a preferred embodiment of the present invention, an oven operates under at least two different modes, namely, cook_setting_development mode and cook_with_setting mode. During the cook_setting_development mode, various cook settings for different food items can be developed and stored in a non-volatile memory within the oven. During the cook_with_setting mode, a specific cook setting corresponding to a food item to be cooked is recalled from the non-volatile memory, and the food item is cooked in the oven with the specific cook setting. 
     I. Cook_Setting_Development Mode 
     When a cook is performed on a first food item during the cook_setting_development mode, instant oven temperatures are measured throughout the cook cycle of the first food item, and all the measured instant oven temperatures are stored in a memory array within a volatile memory of the oven, as shown in block  21  of  FIG. 2 . Preferably, each entry of the array contains the instant oven temperature at each one second of the cook cycle. The array is to be viewed to have ten equal-sized sections. So, for a four-minute cook cycle, the array will contain 4×60=240 instant oven temperature data points, and each of the ten sections contains 240/10=24 instant oven temperature data points. As another example, if the cook cycle is six minutes, then the array will contain 6×60=360 instant oven temperature data points, and each of the ten sections contains 360/10=36 instant temperature data points. 
     After the cook cycle has been completed, the array should be populated with instant oven temperatures accordingly, and the number of temperature data points depends on the length of time of the cook cycle. At this point, if the temperature data points within the array are not saved by a user, such as a chef, the temperature data points within the array will eventually be discarded or overwritten by new temperature data points during a subsequent cook, as depicted in block  22  of  FIG. 2 . 
     However, if the chef is completely satisfied with the quality of the cooked first food item and considers the first food item is perfectly cooked, the chef can press a button on a user interface, such as user interface panel  15  from  FIG. 1 , to cause the average temperature of each of the ten sections within the array to be calculated, and to cause the ten average temperatures to be stored in the non-volatile memory along with the cook setting that was previously used to achieve the perfectly cooked food under a cook setting name such as Cook_setting X, as shown in block  23  of  FIG. 2 . 
     II. Cook_with_Setting Mode 
     When cooking a second food item, which is substantially similar to the first cook item, under the cook_with_setting mode, cook setting Cook_setting X is initially recalled from the non-volatile memory within the oven. During the cook cycle of the second food item, the instant oven temperatures are measured during the cook cycle, as shown in block  31  of  FIG. 3 . An average value of the measured instant oven temperatures is obtained at or near the end of each tenth segment of the cook cycle, as depicted in block  32  of  FIG. 3 . The average oven temperature value obtained at the end of each tenth segment of the cook cycle is compared to the stored average temperature value associated with Cook_setting X for the same time segment of the cook cycle, as shown in block  33  of  FIG. 3 . 
     If the average oven temperature value of the “current” cook for the second food item is different from the stored average temperature value, then the time duration of that tenth segment of the cook cycle is extended or reduced by a correction factor of the time duration of that tenth segment of the cook cycle, as depicted in block  34  of  FIG. 3 . In essence, when cooking the second food item, the cook setting of the oven is dynamically adjusted according to the comparison of the average oven temperature values to the stored average values associated with Cook_setting X at the same time segments during the cook of the first food item. 
     For example, suppose the total cook time for the second food item, which is similar to the first food item, is five minutes (i.e., 300 seconds). If the stored average temperature value for the first tenth segment of the five-minute cook cycle (i.e., 30 seconds) is 450 degrees, and the measured average temperature value for the first tenth segment of the current cook (i.e., 30 seconds) is 441 degrees, that means there is a 450−441=9 degrees (or 9/450×100%=2%) difference between the stored and measured average temperature values. Based on that, the first tenth segment of the current cook can be extended by using a correction factor. When a correction factor of 2 is employed, then the first tenth segment of the current cook is extended by twice that amount, i.e., 2×2% ×30 seconds=1.2 seconds. Thus, if the measured average temperature value in each of the ten segments of the current cook is 9 degrees (or 2%) lower than its stored average temperature value counterpart, then the total cook time for the second food item will be extended by 10×1.2 seconds=12 seconds. 
     Although a correction factor of 2 is used in the above-mentioned example, it is understood by those skilled in the art that the correction factor can be any numerical value. In addition, while the difference between the measured and stored average temperature values in each of the ten segments of the current cook is shown to be the same (i.e., 9 degrees lower) in the above-mentioned example, it is understood by those skilled in the art that the average temperature difference may vary from one segment to another, and from one cook cycle to another. 
     It is also understood by those skilled in the art that the difference between the measured and stored average temperature value can be a positive number, a negative number or zero. A positive number will result in a reduction of the corresponding tenth segment of the current cook cycle. A negative number will result in an extension of the corresponding tenth segment of the current cook cycle. A zero means nothing needs to be changed to the corresponding tenth segment of the current cook cycle. A total cook cycle can have any of the positive, negative and zero average temperature differences. Thus, an entire current cook cycle for the second food item may have, for example, 3 time extensions (to increase the corresponding tenth segments of the current cook cycle by a total of 10 seconds) and 2 time reductions (to reduce the corresponding tenth segments of the current cook cycle by a total of 8 seconds) for a net change in the total cook time of an additional 2 seconds. 
     As has been described, the present invention provides an improved method of cooking in an oven. While all conventional ovens capture an instant oven temperature and use it in the temperature feedback loop, then discard it immediately thereafter, the method of the present invention captures a history of instant oven temperatures for a “perfect” cook, and compares each subsequent cook to that perfect cook as the cook is unfolding and makes a series of small adjustments to the cook cycle based on those differences so that the conditions that resulted in the “perfect” cook can be duplicated as closely as possible. 
     Those skilled in the art will appreciate that the mechanisms of the present invention are capable of being distributed as a program product in a variety of recordable type media such as compact discs and digital video discs. 
     While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.