Microwave heating apparatus

• US 10,271,388 B2
• Filed: 01/23/2013
• Issued: 04/23/2019
• Est. Priority Date: 01/23/2012
• Status: Active Grant

• Current Assignee: Whirlpool Corporation
• Original Assignee: Whirlpool Corporation
• Inventors: Hallgren, Fredrik, Parachini, Davide, Santacatterina, Gianpiero, Devito, Daniele
• Primary Examiner(s): Stapleton, Eric
• Application Number:
  US13/747,847
• Publication Number:
  US 20130186887A1
• Time in Patent Office: 2,281 Days
• Field of Search: 219702
• 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 6/68 for monitoring or control
• CPC Class Codes: H05B 6/686 Circuits comprising a signal generator and power amplifier, e.g. using solid state oscillators
• CPC Class Codes: H05B 6/688 for thawing
• CPC Class Codes: H05B 6/705 using microwave tuning
• 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

A microwave heating apparatus and a method of heating a load using microwaves is disclosed. The microwave heating apparatus comprises a cavity arranged to receive a load, a plurality of feeding ports for feeding microwaves from a plurality of microwave generators to the cavity, and a control unit. The control unit is configured to obtain a desired temperature pattern within the cavity based on information about a plurality of regions of the load. The control unit is also configured to determine a heating pattern comprising zones of different intensities corresponding to the desired temperature pattern, and control at least one of the plurality of microwave generators for providing the heating pattern within the cavity. The apparatus and method may provide heating of a load according to different desired temperatures in various parts of the load.

Claims

1. A microwave heating apparatus comprising:

a cavity arranged to receive at least one load having load regions;

a plurality of independently controllable microwave generators;

a plurality of feeding ports configured to feed microwaves from the plurality of microwave generators to the cavity, wherein the microwaves provide mode fields in the cavity; and

a control unit configured to;

obtain a desired temperature pattern for the at least one load based on information about the load regions;

determine a heating pattern in the cavity comprising zones of different intensities corresponding to the desired temperature pattern, wherein a zone of higher intensity in the determined heating pattern corresponds to a region requiring higher temperature in the desired temperature pattern; and

control at least one of the plurality of independently controllable microwave generators or the plurality of feeding ports so the mode fields form the determined heating pattern and thereby heat the at least one load according to the desired temperature pattern.

2. The microwave heating apparatus of claim 1, wherein the control unit is configured to receive information about measurements of the amount of microwaves reflected from the cavity and at least one of the plurality of independently controllable microwave generators or the plurality of feeding ports based also on that information.

3. The microwave heating apparatus of claim 1, wherein the information about the load regions includes at least one of the location of the load regions within the cavity, a food type corresponding to the load regions, a weight of the load regions, a volume of the load regions or an instantaneous temperature of the load regions.

4. The microwave heating apparatus of claim 1, further comprising an image capturing device arranged to acquire an image of the load arranged in the cavity wherein the control unit is further configured to derive the information about the load regions from the image.

5. The microwave heating apparatus of claim 4, wherein the image capturing device includes a charge-coupled device whose sensitivity extends into the infrared range.

6. The microwave heating apparatus of claim 1, wherein the desired temperature pattern represents different desired finishing temperatures for different load regions.

7. The microwave heating apparatus of claim 1, further comprising an infrared sensor for capturing a temperature image of the load regions wherein the control unit is further configured to derive the information about the load regions from the temperature image.

8. The microwave heating apparatus of claim 1, further comprising an entry means for user entry of at least a portion of the information about the load regions.

9. The microwave heating apparatus of claim 8, wherein the entry means includes a touch screen display for displaying the load located in the cavity and for selection of a cooking level for the load regions, the temperature pattern corresponding to the selected cooking level.

10. The microwave heating apparatus of claim 1, wherein the control unit is configured to control at least one of a frequency, a phase or an amplitude of the microwaves of at least some of the microwave generators for providing the determined heating pattern.

11. The microwave heating apparatus of claim 1, wherein the plurality of microwave generators includes at least one of a solid state microwave generator or a frequency-controllable magnetron.

12. The microwave heating apparatus of claim 1, wherein the control unit is configured to control some of the microwave generators for simultaneous feeding of microwaves to the cavity.

13. The microwave heating apparatus of claim 1, wherein the plurality of microwave generators includes magnetrons, the control unit being configured to control some of the magnetrons for feeding of microwaves to the cavity during different time periods.

14. The microwave heating apparatus of claim 1, wherein the control unit is configured to select some of the feeding ports and microwave generators based on the determined heating pattern.

15. A microwave heating apparatus comprising:

a cavity configured to receive a load;

at least one microwave port configured to supply a signal from at least one signal generator to the cavity, the signal being generated by at least one of a solid state microwave generator or a frequency-controllable magnetron, wherein the signal is configured to provide a mode field in the cavity; and

a control unit, wherein the control unit is configured to obtain a desired temperature pattern within the cavity based on at least one sensed input in at least one region of the load to determine a heating pattern correlating to the desired temperature pattern and comprising a plurality of zones having different intensities, the intensities corresponding to the desired temperature pattern, wherein a zone of higher intensity in the determined heating pattern corresponds to a region of higher temperature in the desired temperature pattern; and

wherein the control unit is configured to control at least one of a plurality of signals generated by the signal generator for combining mode fields provided by at least one of the signal generators thereby providing the heating pattern within said cavity.

16. The microwave heating apparatus of claim 15, wherein the desired temperature pattern is based on at least one of a location of the load regions, a food type corresponding to the load regions, a weight of the load regions, a volume of the load regions or an instantaneous temperature of the load regions within the cavity.

17. The microwave heating apparatus of claim 15, further comprising an image capturing device configured to acquire an image of the load arranged in the cavity, the control unit being configured to obtain the desired temperature pattern based on the image.

18. The microwave heating apparatus of claim 15, further comprising an infrared sensor for at least one of capturing a temperature image of the load regions wherein the control unit is further configured to derive information about the load regions from the temperature image.

19. The microwave heating apparatus of claim 15, further comprising an entry means for user entry of at least one of a location of the load regions, a food type corresponding to the load regions, a weight of the load regions, a volume of the load regions, an instantaneous temperature of the load regions, a desired finishing temperature for the load regions within the cavity, or a selected cooking program from a set of cooking programs wherein the control unit is further configured to correlate the desired temperature pattern and the determined heating pattern based on the user entry.