Microwave Oven

• US 20090321427A1
• Filed: 07/31/2008
• Published: 12/31/2009
• Est. Priority Date: 06/30/2008
• Status: Active Grant

• Current Assignee: Enterprise Science Fund, LLC (Intellectual Ventures LLC)
• Original Assignee: The Invention Science Fund I, L.L.C. (Intellectual Ventures LLC)
• Inventors: Ishikawa, Muriel Y., Myhrvold, Nathan P., Tegreene, Clarence T., Jung, Edward K.Y., Wood, Lowell L. JR., Hyde, Roderick A.
• Granted Patent: US 8,610,038 B2
• Time in Patent Office: Days
• US Class Current: 219/702
• CPC Class Codes: H05B 6/6447 Method of operation or details of the microwave heating apparatus related to the use of detectors or sensors
• CPC Class Codes: H05B 6/6455 the sensors being infrared detectors
• CPC Class Codes: H05B 6/705 using microwave tuning
• CPC Class Codes: H05B 6/72 Radiators or antennas
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

Abstract

Generally and not exclusively, a microwave cooking oven to cook food in a microwave chamber includes at least one array of radiation detectors. An exemplary method includes sensing an optical depth of the item along each of multiple beam paths from at least two sides of the item, and mapping isothermal regions in the interior of the item 3-dimensionally based on the sensing. Another exemplary method includes sensing a microwave power representing a value of a heatability property for each of multiple regions of the same item, and applying a different measure of the microwave power to each of the different regions according to the value of the heatability property in each individual region. Yet another exemplary method includes sensing different frequencies of the microwave power in the microwave chamber, and changing the frequency of the microwave power for heating the item, as the item undergoes heating.

Claims

1. A method, comprising:

emitting microwave power to a microwave chamber;

dynamically sensing the microwave power in the microwave chamber at an array of locations in the microwave chamber;

modeling a relationship between the sensed microwave power and a heatability property of an item in the microwave chamber; and

controlling the emitting of the microwave power based on the modeling.

2. The method as recited in claim 1, wherein dynamically sensing the microwave power in the comprises:

detecting an intensity of the microwave power.

3. The method as recited in claim 1, wherein dynamically sensing the microwave power in the comprises:

detecting a frequency of the microwave power.

4. The method as recited in claim 1, wherein dynamically sensing the microwave power in the comprises:

detecting a duration of the microwave power.

5. The method as recited in claim 1, wherein emitting microwave power to a microwave chamber comprises:

transferring the microwave power to the microwave chamber via multiple beam paths, wherein each beam path has an origin on one side of the item and a termination on an opposing side of the item; and

wherein dynamically sensing the microwave power in the comprises;

sensing at least part of the microwave power on a termination side of each beam path.

6. The method as recited in claim 5, further comprising:

redirecting at least one of the beam paths from a first target location in the microwave chamber to a second target location in the microwave chamber.

7. The method as recited in claim 6, wherein redirecting at least one of the beam paths from a first target location in the microwave chamber to a second target location in the microwave chamber comprises:

switching from a first emitter to a second emitter in an array of microwave emitters to change a beam path from one part of the microwave chamber to another part of the microwave chamber; and

sensing the microwave power associated with a termination side of each beam path.

8. The method as recited in claim 6, wherein redirecting at least one of the beam paths from a first target location in the microwave chamber to a second target location in the microwave chamber comprises:

changing a position of a metallic vane to reflect microwaves associated with an emitter emitting the microwave power for at least one of the beam paths.

9. The method as recited in claim 1, wherein dynamically sensing the microwave power in the comprises:

sensing the microwave power in the microwave chamber at multiple locations to one side of the item.

10. The method as recited in claim 9, wherein sensing the microwave power in the microwave chamber at multiple locations to one side of the item comprises:

sensing the microwave power at each termination of a beam path.

11. The method as recited in claim 9, wherein sensing the microwave power in the microwave chamber at multiple locations to one side of the item comprises:

sensing the microwave power at an array of locations on one or more sides of the microwave chamber.

12. The method as recited in claim 11, wherein sensing the microwave power at an array of locations on one or more sides of the microwave chamber comprises:

sensing the microwave power at an array of locations that has a higher number of sensors than a number of emitters in an array of emitters for emitting the microwave power for the multiple beam paths, to provide increased sensing resolution.

13. The method as recited in claim 9, further comprising:

emitting a first measure of the microwave power to the microwave chamber for a first interval;

turning off the emitting;

for a second interval, sensing a second measure of the microwave power as an emission of radiation from the item, wherein the microwave power absorbed by the item spontaneously radiates from the item; and

mapping isothermal regions of the item based on the sensed microwave power.

14. The method as recited in claim 13, further comprising:

sensing the second measure of the microwave power at different sensor arrays disposed on at least two different sides of the item; and

mapping one or more 3-dimensional isothermal regions in the interior of the item based on the sensing the second measure of the microwave power at different sensor arrays disposed on at least two different sides of the item.

15. The method as recited in claim 14, further comprising:

sensing an infrared image of one or more surfaces of the item;

mapping isothermal areas of one or more surfaces of the item based on the infrared image; and

associating the isothermal regions in the interior of the item with the isothermal areas on the one or more surfaces of the item.

16. The method as recited in claim 15, further comprising:

refining the mapping of the isothermal regions in the interior of the item based on the associating the isothermal regions in the interior of the item with the isothermal areas on the one or more surfaces of the item.

17. The method as recited in claim 9, further comprising:

sensing an optical depth of the item along each of multiple beam paths;

associating each sensed optical depth with a local absorptivity of the item;

associating each local absorptivity with a temperature; and

mapping isothermal regions in the interior of the item based on the sensing.

18. The method as recited in claim 17, wherein sensing an optical depth of the item along each of multiple beam paths comprises:

sensing an optical depth of the item along each of multiple beam paths from at least two sides of the item; and

wherein mapping isothermal regions in the interior of the item based on the sensing comprises;

3-dimensional mapping isothermal regions in the interior of the item based on the sensing.

19. The method as recited in claim 9, further comprising:

sensing a power level of at least two beam paths of the microwave power; and

triangulating a location of an interior isothermal region of the item, wherein the interior isothermal region varies in temperature beyond a threshold from an adjacent region in the item.

20. The method as recited in claim 19, wherein the interior isothermal region has a temperature lower than its surrounding regions, the method further comprising:

directing a microwave beam path to the interior isothermal region to heat the interior isothermal region.

21. The method as recited in claim 19, wherein the interior isothermal region has a temperature higher than its surrounding regions, the method further comprising:

directing a beam path away from the interior isothermal region to cool the interior isothermal region.

22. The method as recited in claim 9, wherein sensing the microwave power in the microwave chamber at multiple locations to one side of the item comprises:

differentially sensing microwave beam paths, including;

assigning a microwave frequency to each emitter that emits the microwave power for a beam path; and

sensing the microwave frequency of each beam path at multiple locations in the microwave chamber.

23. The method as recited in claim 22, further comprising:

sensing a first optical depth of a surface layer of the item, wherein the first optical depth is associated with a first microwave frequency assigned to a first beam path;

sensing a second optical depth of a non-surface layer of the item, wherein the second optical depth is associated with a second microwave frequency assigned to a second beam path;

heating the surface layer via the first beam path using the first microwave frequency; and

heating the non-surface layer via the second beam path using the second microwave frequency.

24. The method as recited in claim 5, further comprising:

scanning the microwave chamber for a presence of the item, wherein at least one beam path is redirectable to different parts of the microwave chamber; and

wherein sensing at least part of the microwave power on a termination side of each beam path comprises;

detecting an attenuation of the microwave power associated with each beam path that is intersected by the item.

25. The method as recited in claim 24, wherein scanning the microwave chamber for a presence of the item comprises:

determining a shape and a geometry of the item.

26. The method as recited in claim 24, wherein scanning the microwave chamber for a presence of the item comprises:

differentiating multiple items in the microwave chamber, including determining a unique shape and geometry of each item.

27. The method as recited in claim 24, wherein scanning the microwave chamber for a presence of the item comprises:

directing the multiple beam paths through the microwave chamber from at least two different sides of the microwave chamber to sense a 3-dimensional shape and geometry of the item.

28. The method as recited in claim 27, further comprising:

sensing a value of the heatability property in different regions of the same item.

29. The method as recited in claim 28, further comprising:

applying a different measure of the microwave power to each of the different regions according to the value of the heatability property in each individual region.

30. The method as recited in claim 29, further comprising:

separately sensing a variation in the value of the heatability property in each region; and

dynamically controlling the measure of the microwave power applied to each different region based on each variation.

31. The method as recited in claim 28, further comprising:

sensing multiple heatability properties of the item;

sensing a variation of one of the heatability properties in different regions of the item; and

dynamically controlling the measure of the microwave power applied to each different region based on a different heatability property associated with each region.

32. The method as recited in claim 31, further comprising:

separately modeling the heatability property of each region; and

dynamically controlling the measure of the microwave power applied to each different region based on the model associated with each region.

33. The method as recited in claim 32, further comprising:

dynamically controlling the measure of the microwave power applied to each different region using different microwave beam paths.

34. The method as recited in claim 1, wherein modeling a relationship between the sensed microwave power and a heatability property of an item in the microwave chamber comprises:

relating the sensed microwave power to a microwave absorptivity of the item.

35. The method as recited in claim 1, wherein modeling a relationship between the sensed microwave power and a heatability property of an item in the microwave chamber comprises:

relating the sensed microwave power to an optical depth of the item.

36. The method as recited in claim 1, wherein modeling a relationship between the sensed microwave power and a heatability property of an item in the microwave chamber comprises:

relating the sensed microwave power to a temperature of the item.

37. The method as recited in claim 1, wherein modeling a relationship between the sensed microwave power and a heatability property of an item in the microwave chamber comprises:

relating the sensed microwave power to a dielectric property of the item.

38. The method as recited in claim 1, wherein modeling a relationship between the sensed microwave power and a heatability property of an item in the microwave chamber comprises:

relating the sensed microwave power to a physical state of a carbohydrate, a protein, or a fat in the item.

39. The method as recited in claim 1, wherein modeling a relationship between the sensed microwave power and a heatability property of an item in the microwave chamber comprises:

relating the sensed microwave power to a liquid food state of the item.

40. The method as recited in claim 1, wherein modeling a relationship between the sensed microwave power and a heatability property of an item in the microwave chamber comprises:

relating the sensed microwave power to a moisture content of the item.

41. The method as recited in claim 1, wherein modeling a relationship between the sensed microwave power and a heatability property of an item in the microwave chamber comprises:

relating the sensed microwave power to a physical geometry of the item.

42. The method as recited in claim 1, wherein modeling a relationship between the sensed microwave power and a heatability property of an item in the microwave chamber comprises:

relating the sensed microwave power to a type of food of the item.

43. The method as recited in claim 1, wherein modeling a relationship between the sensed microwave power and a heatability property of an item in the microwave chamber comprises:

selecting a type of modeling based on a sensed microwave power.

44. The method as recited in claim 1, further comprising:

estimating a food type, including;

sensing the microwave power in the microwave chamber to estimate a geometry of the item;

sensing the microwave power in the microwave chamber to estimate an optical depth of the item; and

estimating a food type of the item based on the geometry and the optical depth.

46. The method as recited in claim 44, further comprising:

sensing the microwave power in the microwave chamber to estimate a food type and temperature of the item; and

wherein estimating a food type of the item based on the geometry and the optical depth. comprises;

estimating a food type of the item based on the geometry and the optical depth. at a given temperature.

47. The method as recited in claim 46, further comprising:

estimating the temperature of the item from the optical depth.

48. The method as recited in claim 1, further comprising:

iteratively sensing the microwave power in the microwave chamber at the array of locations in the microwave chamber and controlling the emitting of the microwave power based on modeling the relationship between the sensed microwave power and a heatability property of an item in the microwave chamber.

49. The method as recited in claim 1, further comprising dynamically changing the sensing based on one changes in one of the emitting, the modeling, or the controlling.

50. The method as recited in claim 1, wherein the sensing the microwave power in the microwave chamber at an away of locations in the microwave chamber comprises:

sensing different frequencies of the microwave power in the microwave chamber;

modeling a microwave absorptivity versus frequency relationship for a given item being heated;

selecting one of the frequencies of the microwave power for heating the item, based on the modeling.

51. The method as recited in claim 50, further comprising sensing the microwave power in the microwave chamber at the selected frequency;

detecting a change in the absorptivity as the item is heated; and

changing the frequency of the microwave power for heating the item when the absorptivity changes, based on the modeling.

45. (canceled)

52. A system, comprising:

means for emitting microwave power into a microwave chamber;

means for sensing a level of at least part of the microwave power in the microwave chamber;

means for modeling a relationship between the sensed level of the microwave power and a heatability property of an item in the microwave chamber; and

means for dynamically controlling the means for emitting microwave power based on a signal from the means for modeling.

53-69. -69. (canceled)

70. A microwave oven, comprising:

a microwave chamber for receiving a food item to be cooked and for receiving microwave power for cooking the food item;

magnetrons for emitting microwave power, wherein the magnetrons are disposed in one or more arrays on the exterior of one or more sides of the microwave chamber;

detector diodes for measuring microwave power in the microwave chamber, wherein the detector diodes are disposed in one or more arrays on one or more sides of the microwave chamber opposing the magnetrons;

a modeling engine for modeling one or more relationships between the measured level of the microwave power and one or more heatability properties of the food item; and

a controller for dynamically managing the operation of the magnetrons, based on one or more signals from the modeling engine.

71. The microwave oven as recited in claim 70, wherein the magnetrons transfer the microwave power to the microwave chamber via multiple beam paths;

and

wherein the detector diodes measure at least part of the microwave power of each beam path.

72. The microwave oven as recited in claim 71, wherein the magnetrons are capable of directing a beam path to different parts of the microwave chamber.

73. The microwave oven as recited in claim 72, wherein the detector diodes measure the microwave power in the microwave chamber at multiple locations to one side of the food item.

74. The microwave oven as recited in claim 72, wherein the detector diodes measure the microwave power at an array of locations on one or more sides of the microwave chamber.

75. The microwave oven as recited in claim 74, wherein the modeling engine models an optical depth of the food item along each of multiple beam paths based on the measured microwave power at the array of locations;

wherein the modeling engine associates each sensed optical depth with a local absorptivity of the food item;

wherein the modeling engine associates each local absorptivity with a temperature; and

wherein the modeling engine maps one or more isothermal regions in the interior of the food item, based on one of the individual temperatures.

76. The microwave oven as recited in claim 75, wherein the modeling engine models an optical depth of the food item along each of multiple beams paths from at least two sides of the food item;

and

wherein the modeling engine 3-dimensionally maps the isothermal regions in the interior of the food item.

77. The microwave oven as recited in claim 74, wherein the detector diodes measure a power level of at least two microwave beam paths;

and

wherein the modeling engine triangulates a location of an interior isothermal region of the food item, wherein the interior isothermal region varies in temperature beyond a threshold from its surrounding regions.

78. The microwave oven as recited in claim 77, wherein the controller directs a microwave beam path to an interior isothermal region that has a temperature lower than its surrounding regions to heat the isothermal region.

79. The microwave oven as recited in claim 77, wherein the controller directs a beam path away from an interior isothermal region that has a temperature higher than its surrounding regions to cool the isothermal region.

80-87. -87. (canceled)