Microwave heating device

Abstract

To provide a microwave heating device that enables cooking methods more suitable for the food being heated. [Solution] The microwave heating device (100) comprises a heating chamber (101) in which objects to be heated (102A, 102B) are placed, a microwave generating unit (103) that generates microwaves, a microwave radiating unit (104) that radiates the microwaves generated by the microwave generating unit (103) into the heating chamber (101), and a dividing unit (105) that divides the space of the heating chamber (101) into at least two divided chambers (128A, 128B).

Description

Technical Field

[0001] The present disclosure relates to a microwave heating device.

Background Art

[0002] Conventionally, a microwave heating device is known that accommodates an object to be heated, such as food, in a heating chamber and supplies microwaves into the heating chamber to cook the object to be heated (see, for example, Patent Document 1).

[0003] The microwave heating device of Patent Document 1 includes a microwave generation unit that generates microwaves and a microwave radiation unit that radiates the microwaves generated by the microwave generation unit into the heating chamber.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present disclosure provides a microwave heating device capable of performing cooking more suitable for the object to be heated.

Means for Solving the Problems

[0006] A microwave heating device according to an aspect of the present disclosure includes a heating chamber in which an object to be heated is disposed, a microwave generation unit that generates microwaves, a microwave radiation unit that radiates the microwaves generated by the microwave generation unit into the heating chamber, and a dividing unit that divides the space of the heating chamber into at least two divided chambers.

Effects of the Invention

[0007] According to the present disclosure, cooking more suitable for the object to be heated is possible.

Brief Description of the Drawings

[0008] [Figure 1] Schematic front view of an example configuration of a microwave heating apparatus according to Embodiment 1 [Figure 2] Flowchart of an example of operation of the microwave heating apparatus according to Embodiment 1 [Figure 3] Flowchart of an example of operation of the microwave heating apparatus according to Embodiment 1 [Figure 4] Schematic side view of an example configuration of a microwave heating apparatus according to Embodiment 2 [Figure 5] Schematic top view of the heating chamber including the divided section according to Embodiment 2 [Figure 6] Schematic perspective view of the divided section according to Embodiment 2 [Figure 7] Schematic side view of the divided section according to Embodiment 2 [Figure 8] Schematic perspective view of the heating chamber including the divided section according to Embodiment 2 [Figure 9] A schematic front view showing the location where the divided section and the heating chamber wall are in close proximity according to Embodiment 2. [Figure 10] Schematic cross-sectional view of the microwave shielding structure between the radio wave shielding structure and the heating chamber wall according to Modification 1 of Embodiment 2. [Figure 11] Schematic cross-sectional view of the microwave shielding structure between the radio wave shielding structure and the heating chamber wall according to modified example 2 of Embodiment 2. [Figure 12] Schematic cross-sectional view of the microwave shielding structure between the radio wave shielding structure and the heating chamber wall according to modified example 3 of Embodiment 2. [Figure 13] Schematic cross-sectional view of the microwave shielding structure between the radio wave shielding structure and the heating chamber wall according to modified example 4 of Embodiment 2. [Figure 14] Schematic cross-sectional view of the microwave shielding structure between the radio wave shielding structure and the heating chamber wall according to modified example 5 of Embodiment 2. [Figure 15] Schematic cross-sectional view of the microwave shielding structure between the radio wave shielding structure and the heating chamber wall according to modified example 6 of Embodiment 2. [Figure 16]Schematic cross-sectional view of the microwave shielding structure between the radio wave shielding structure according to Modification Example 7 of Embodiment 2 and the inner wall of the heating chamber [Figure 17] Schematic cross-sectional view of the microwave shielding structure between the radio wave shielding structure according to Modification Example 8 of Embodiment 2 and the inner wall of the heating chamber [Figure 18A] Schematic side view of a configuration example of a microwave heating device according to Embodiment 3 [Figure 18B] Schematic side view of a configuration example of a microwave heating device according to a modification of Embodiment 3 [Figure 19] Schematic top view of the dividing part according to Embodiment 3 [Figure 20] Schematic cross-sectional view of the dividing part according to Embodiment 3 as viewed from the front side [Figure 21] Schematic front view showing an operation example of the rotating antenna according to Embodiment 3 [Figure 22] Schematic front view showing an operation example of the rotating antenna according to Embodiment 3 [Figure 23] Schematic front view showing an operation example of the rotating antenna according to Embodiment 3 [Figure 24] Schematic diagram regarding an example of use of a microwave sensor using the heating device according to Embodiment 3 [Figure 25] Flowchart of an example of the operation of the microwave heating device according to Embodiment 3 [Figure 26] Explanation diagram of detection of the state change of the object to be heated according to Embodiment 3 [Figure 27] Flowchart of an example of the operation of the microwave heating device according to Embodiment 3 [Figure 28] Explanation diagram of detection of the state change of the object to be heated according to Embodiment 3 [Figure 29] Explanation diagram of detection of the state change of the object to be heated according to Embodiment 3 [Figure 30] Explanation diagram of detection of the state change of the object to be heated according to Embodiment 3 [Figure 31] Explanation diagram of detection of the state change of the object to be heated according to Embodiment 3 [Figure 32] Explanation diagram of detection of the state change of the object to be heated according to Embodiment 3 [Figure 33] Schematic top view of an example configuration of a microwave heating apparatus according to Embodiment 4 [Figure 34] Schematic front view of an example configuration of a microwave heating apparatus according to Embodiment 5 [Figure 35] Schematic side view of an example configuration of a microwave heating apparatus according to Embodiment 6 [Figure 36] Schematic front view of an example configuration of a microwave heating apparatus according to Embodiment 7 [Figure 37] Schematic top view of an example configuration of a microwave heating apparatus according to Embodiment 8 [Figure 38] Schematic top view of an example configuration of a microwave heating apparatus according to Modification 1 of Embodiment 8 [Figure 39] Schematic top view of an example configuration of a microwave heating apparatus according to a modified example 2 of Embodiment 8. [Figure 40] Schematic top view of an example configuration of a microwave heating apparatus according to Embodiment 9 [Figure 41] Schematic front view of an example configuration of a microwave heating apparatus according to Embodiment 9 [Figure 42] Schematic front view of an example configuration of a microwave heating apparatus according to Embodiment 10 [Figure 43] A diagram illustrating the heating distribution of an object being heated when the phase difference is 0°. [Figure 44] A diagram illustrating the heating distribution of an object being heated when the phase difference is 180°. [Figure 45] This diagram illustrates the heating distribution of an object being heated when combining phase differences of 0° and 180°. [Figure 46] Diagram illustrating the heating distribution of the heated object in the comparative example. [Figure 47] A diagram illustrating the heat distribution of the heated object after heat treatment in the comparative example. [Figure 48] Diagram illustrating the model used to simulate the radio wave distribution in the heating chamber and the heating distribution of the object being heated, based on frequency and phase difference. [Figure 49] Figure 48 illustrates the differences in the radio wave distribution in the heating chamber and the heating distribution of the object being heated, based on frequency and phase difference, in the model shown. [Figure 50]Schematic front view of an example configuration of a microwave heating apparatus according to Embodiment 11 [Figure 51] A diagram illustrating the difference in heating distribution of an object being heated due to frequency and phase difference. [Figure 52] A diagram illustrating the difference in heating distribution of an object being heated due to frequency and phase difference. [Figure 53] Figure 52 shows the heating distribution of the object being heated when the phase difference is 0° and the frequency is 2400MHz. [Figure 54] A diagram illustrating the difference in heating distribution of an object being heated due to frequency and phase difference. [Figure 55] Figure 54 shows the heating distribution of the object being heated when the phase difference is 0° and the frequency is 914MHz. [Figure 56] Schematic front view of an example configuration of a microwave heating apparatus according to Embodiment 12 [Figure 57] Schematic side view of an example configuration of a microwave heating apparatus according to Embodiment 13 [Modes for carrying out the invention]

[0009] The embodiments will be described in detail below, with reference to the drawings as appropriate. However, unnecessary details may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding by those skilled in the art. The inventors provide the accompanying drawings and the following explanation so that those skilled in the art can fully understand this disclosure, and not to limit the subject matter described in the claims.

[0010] [1. Embodiments] [1.1 Embodiment 1] [1.1.1 Configuration] Figure 1 is a schematic front view of an example configuration of a microwave heating device 100 according to Embodiment 1. The microwave heating device 100 is, for example, a microwave processing device such as a microwave oven. The microwave heating device 100 shown in Figure 1 comprises a heating chamber 101, a microwave generating unit 103, a microwave radiating unit 104, a dividing unit 105, sensors 106A and 106B, and a control unit 110.

[0011] The heating chamber 101 forms a space for housing the objects to be heated 102A and 102B and is made of a material that shields against radio waves. The heating chamber 101 is, for example, a rectangular box that houses the objects to be heated 102A and 102B. In Figure 1, the directions related to the heating chamber 101 are shown as the depth direction X, the width direction Y, and the height direction Z. The heating chamber 101 comprises, for example, a left wall, a right wall, a bottom surface 108, a top surface 109, and a back surface made of a material that shields against radio waves, and an opening and closing door that opens and closes to house the objects to be heated 102A and 102B, and is configured to confine the microwaves radiated from the microwave radiation unit 104 inside the heating chamber 101. In this way, the heating chamber 101 is made of a material that shields against radio waves and can form a closed space when heating the objects to be heated 102A and 102B. In this disclosure, "shielding" means attenuating the energy of radio waves by reflection, absorption, multiple reflection, etc. Therefore, any material that can shield radio waves is acceptable as long as it provides this kind of "shielding" effect. Examples of materials that shield radio waves include materials that reflect radio waves, such as metal materials, and materials that absorb radio waves, such as ferrite rubber.

[0012] The microwave generator 103 is a microwave generator that generates microwaves for dielectric heating of the objects to be heated 102A and 102B. The microwave generator 103 generates microwaves using, for example, a magnetron or a semiconductor oscillator. In all embodiments below, the microwave generator may be a magnetron or a semiconductor oscillator. The frequency of the microwaves is, for example, 300 MHz to 1000 GHz. By irradiating a dielectric with microwaves of such frequency, dielectric loss occurs inside the dielectric, generating heat in the dielectric. This allows the dielectric to be heated. In this embodiment, the microwave generator 103 is operable with a commercial AC power supply and generates microwaves based on AC power from the commercial AC power supply.

[0013] The microwave radiating unit 104 is a component that radiates microwaves generated by the microwave generating unit 103 into the heating chamber 101. The microwave radiating unit 104 includes, for example, a waveguide and a rotating antenna (not shown). The configuration including a waveguide and a rotating antenna may be applied in all embodiments below. In this embodiment, the microwave radiating unit 104 is positioned below the bottom surface 108 of the heating chamber 101 and radiates microwaves into the interior of the heating chamber 101 through the bottom surface 108, which is made of a microwave-transmitting material. The microwave radiating unit 104 radiates microwaves into, for example, the divided chambers 128A and 128B, which will be described later.

[0014] The dividing section 105 is a component for dividing the heating chamber 101 into multiple divided chambers 128A and 128B. The dividing section 105 shown in Figure 1 extends along the height direction Z from the bottom surface 108 to the top surface 109 of the heating chamber 101, so as to divide the heating chamber 101 in the width direction Y. The heating chamber 101 is divided into two divided chambers 128A and 128B by the dividing section 105. In the example shown in Figure 1, the object to be heated 102A is placed in the lower divided chamber 128A, and the object to be heated 102B is placed in the upper divided chamber 128B. The dividing section 105 is fixed to the inner wall of the heating chamber 101, for example, and cannot be removed. The dividing section 105 is made of, for example, a radio wave shielding material such as metal, or a radio wave transmitting material such as a dielectric.

[0015] Sensors 106A and 106B are sensors for detecting the internal state of the heating chamber 101. In this embodiment, two sensors 106A and 106B are provided in the heating chamber 101. Sensor 106A is located in the divided chamber 128A, and sensor 106B is located in the divided chamber 128B. Sensors 106A and 106B are, for example, infrared sensors and detect the temperatures of the objects to be heated 102A and 102B placed in the heating chamber 101. Sensor 106A detects the temperature of object 102A, and sensor 106B detects the temperature of object 102B. The temperature information detected by sensors 106A and 106B is transmitted to the control unit 110.

[0016] The control unit 110 is a component that controls the operation of the microwave heating device 100. The control unit 110 is configured, for example, with a microcomputer. The control unit 110 is electrically connected to each component of the microwave heating device 100 and controls the operation of each component. In Figure 1, the electrical connections between the control unit 110 and other components are shown with dotted lines, but in subsequent drawings, the dotted lines and the notation for the control unit will be omitted. The control unit 110 shown in Figure 1 is electrically connected, for example, to the microwave generating unit 103, the microwave radiating unit 104, and sensors 106A and 106B.

[0017] [1.1.2 Operation] The operation of the control unit 110 of the heating device 100 shown in Figure 1 will be explained with reference to the flowcharts shown in Figures 2 and 3.

[0018] As shown in Figure 2, the control unit 110 detects the food items to be heated 102A and 102B based on the detection results of sensors 106A and 106B (S11), receives the menu selection by the user (S12), determines the heating sequence based on the selected menu (S13), and executes the heating process according to the determined heating sequence (S14). A flowchart of the heating process in step S14 is shown in Figure 3.

[0019] As shown in Figure 3, the control unit 110 controls the rotation of the rotating antenna of the microwave radiation unit 104 (S21), drives the microwave generator 103 to generate microwaves, supplies microwave power to the heating chamber 101 via the rotating antenna of the microwave radiation unit 104 (S22), acquires the detection results from sensors 106A and 106B to monitor the progress regarding the heating state of the objects to be heated 102A and 102B (S23), and determines whether or not to terminate the heating process based on the progress results monitored in step S23 (S24). If it is determined not to terminate the heating process (NO in S24), the process returns to step S21. If it is determined to terminate the heating process (YES in S24), the heating process in step S14 is terminated.

[0020] [1.1.3 Effects] The microwave heating apparatus 100 of the above-described embodiment 1 comprises a heating chamber 101 for housing objects to be heated 102A and 102B, a microwave generating unit 103 for generating microwaves, a microwave radiating unit 104 for radiating the microwaves generated by the microwave generating unit 103 into the heating chamber 101, and a dividing unit 105 for dividing the space of the heating chamber 101 into divided chambers 128A and 128B. With this configuration, by dividing the heating chamber 101 into multiple divided chambers 128A and 128B, it is possible to change the heating conditions for each object to be heated 102A and 102B, such as by changing the microwave supply method to each of the divided chambers 128A and 128B. This makes it possible to perform a heating treatment more suitable for the objects to be heated 102A and 102B.

[0021] Furthermore, the heating chamber 101 is divided into two partitioned chambers 128A and 128B. With this configuration, by placing the objects to be heated 102A and 102B in each partitioned chamber 128A and 128B respectively, it is possible to change the heating conditions for each object to be heated 102A and 102B. Moreover, while conventional equipment required heating each object to be heated 102A and 102B individually, it is possible to heat multiple objects to be heated 102A and 102B simultaneously. In addition, by placing the objects to be heated 102A and 102B in partitioned chambers 128A and 128B that are the same size as the objects to be heated 102A and 102B and heating them, highly efficient heating becomes possible. As a result, it is possible to select a heat source suitable for each object to be heated 102A and 102B, enabling simultaneous heating of two items, time-saving and high-temperature heating, and energy-saving heating. Furthermore, the effect is achieved even if the size of the divided chambers 128A and 128B in which the objects to be heated 102A and 102B are placed is smaller than that of the heating chamber 101 before division. In addition, the divided section 105 is not limited to cases where the heating chamber 101 is divided into two divided chambers 128A and 128B, but is sufficient if it is divided into at least two divided chambers (including three or more).

[0022] Furthermore, the heating chamber 101 is divided in the width direction Y. With this configuration, dividing the heating chamber 101 in the width direction Y makes it possible to heat multiple items, and furthermore, divided chambers 128A and 128B can be formed without restricting the height direction Z or depth direction X of the objects to be heated 102A and 102B. This relaxes the dimensional restrictions on the objects to be heated 102A and 102B. This configuration is particularly effective when the objects to be heated 102A and 102B have a large height direction Z, such as a tall glass.

[0023] Furthermore, sensors 106A and 106B are provided in each of the divided chambers 128A and 128B. With this configuration, based on the sensing results of sensors 106A and 106B located in each divided chamber 128A and 128B, the heating conditions using microwaves and other heat sources can be changed, or the heating process can be terminated, thereby enabling heating that is appropriate to the changes in the heating state of the objects to be heated 102A and 102B. This makes it possible to achieve uniform heating and detection of the end of heating (heating at the appropriate temperature).

[0024] Furthermore, infrared sensors are used as sensors 106A and 106B. With this configuration, by detecting the surface temperature of the objects to be heated 102A and 102B, it is possible to change the heating conditions or terminate the heating process in accordance with the temperature change of the objects to be heated 102A and 102B due to heating. In addition, by detecting the initial surface temperature of the objects to be heated 102A and 102B before heating, it is possible to set the heating conditions according to the initial temperature. This enables uniform heating, heating to the appropriate temperature (mitigation of overheating and underheating), and automatic cooking. Note that sensors 106A and 106B are not limited to infrared sensors; any type of sensor may be used, such as a humidity sensor for detecting humidity, a color sensor for detecting color, or a microwave sensor for detecting incident or reflected microwave waves.

[0025] Furthermore, the microwave radiation unit 104 radiates microwaves into the heating chamber 101 from the bottom surface 108 of the heating chamber 101. With this configuration, by supplying microwaves from the bottom surface 108 of the heating chamber 101, it is possible to strongly incident microwaves on the objects to be heated 102A and 102B from below. Therefore, especially when heating liquids, the temperature of the lower part can be increased, upward convection occurs within the objects to be heated 102A and 102B, improving heating efficiency and reducing uneven heating. In addition, since the lower parts of the objects to be heated 102A and 102B are in contact with a plate or the like, when heating above room temperature, heat transfer occurs from the objects to be heated 102A and 102B to the plate or the like, so the temperature of the lower parts of the objects to be heated 102A and 102B tends to be lower. Therefore, by supplying microwaves to the objects to be heated 102A and 102B from below, it is possible to further increase the temperature of the lower parts of the objects to be heated 102A and 102B. This enables highly efficient heating, faster cooking times, and uniform heating.

[0026] Furthermore, the divided section 105 is fixed to the heating chamber 101. With this configuration, when shielding microwaves by making the divided section 105 and the inner wall of the heating chamber 101 out of metal, higher shielding performance can be achieved. In addition, by fixing the divided section 105 and preventing its removal, the risk of deformation of the radio wave shielding structure due to the removal of the divided section 105 can be reduced. This makes it possible to improve and stabilize the shielding performance. When fixing the divided section 105 to the heating chamber 101, the divided section 105 and the inner wall of the heating chamber 101 are electrically connected. The spacing between the fixed parts needs to be shorter than half the microwave wavelength in the direction of the edge of the divided section 105 (depth direction X). In practice, considering that there may be cases where the fixing is partially insufficient, the spacing may be shorter than 1 / 4 of the microwave wavelength.

[0027] The microwave heating apparatuses of Embodiment 2 and later may also exhibit the same effects and advantages as described above. In the following description, effects and advantages that overlap with those of Embodiment 1 will be omitted as appropriate.

[0028] [1.2 Embodiment 2] [1.2.1 Structure] Figure 4 is a schematic side view of an example configuration of a microwave heating apparatus 200 according to Embodiment 2. The microwave heating apparatus 200 shown in Figure 4 comprises a heating chamber 201, a microwave generating unit 203, a microwave radiating unit 204, dividing units 205 and 206, a camera 207, a steam sensor 208, and a control unit 211.

[0029] The heating chamber 201 shown in Figure 4 is divided in the height direction Z by two dividing sections 205 and 206, forming three divided chambers 228A, 228B, and 228C. As shown in Figure 4, two objects to be heated 250A are placed in the lower divided chamber 228A, one object to be heated 250B is placed in the middle divided chamber 228B, and one object to be heated 250C is placed in the upper divided chamber 228C.

[0030] The microwave radiating unit 204 is located on the back side of the back surface 220 of the heating chamber 201. The microwave radiating unit 204 radiates microwaves toward the heating chamber 201 from the back surface 220, which is made of a microwave-transmitting material. The microwave radiating unit 204 has a rotating antenna 209. The rotating antenna 209 has an aperture that radiates microwaves and has a rotation function. The rotating antenna 209, having a rotation function, can change the position of the aperture that radiates microwaves and the direction of radiation. The rotating antenna 209 radiates microwaves toward, for example, the middle divided chamber 228B and the upper divided chamber 228C, respectively. The rotating antenna 209 radiates microwaves toward the divided chamber 228B in a first rotation range and radiates microwaves toward the divided chamber 228C in a second rotation range.

[0031] Camera 207 is a sensor that images the inside of the heating chamber 201. Camera 207 is, for example, mounted on the top surface 212 of the heating chamber 201 and images the upper divided chamber 228C. Steam sensor 208 is a sensor that detects steam in the heating chamber 201. Steam sensor 208 is, for example, mounted on the top surface 212 of the heating chamber 201 and detects steam present in the upper divided chamber 228C. For example, camera 207 is mounted on the front side X1 and steam sensor 208 is mounted on the rear side X2, but they may be placed in any position.

[0032] Each of the divided sections 205 and 206 is made of, for example, a metal that shields microwaves, and has radio wave shielding structures 210 and 211 at its ends. Here, the radio wave shielding structures 210 and 211 will be explained using Figures 5 to 7. The radio wave shielding structures 210 and 211 each have similar structures, and in Figures 5 to 7, the radio wave shielding structure 210 of the divided section 205 will be explained as a representative example.

[0033] Figure 5 is a top view of the heating chamber 201 including the divided section 205, Figure 6 is a perspective view of the divided section 205, and Figure 7 is a side view of the divided section 205. Figure 8 is a schematic perspective view of the heating chamber 201 including the divided section 205, and Figure 9 is a schematic front view showing the area where the divided section 205 and the inner wall 214 of the heating chamber 205 are in close proximity.

[0034] As shown in Figures 5 and 6, the divided section 205 has a central mounting surface 252 for placing the object to be heated 250B. The divided section 205 has radio wave shielding structures 210 on all four sides. The radio wave shielding structure 210 includes a radio wave shielding structure 210A provided on the straight sections of the divided section 205 and a radio wave shielding structure 210B provided on the corners of the divided section 205. The radio wave shielding structure 210A has, for example, a plurality of choke structures arranged regularly in a row. The radio wave shielding structure 210B has a different structure from the radio wave shielding structure 210A, for example, a structure in which the choke structures at the ends of the first row and the choke structures at the ends of the second row adjacent to the first row are arranged with a gap between them. As shown in Figure 5, the radio wave shielding structures 210A are provided on all four sides of the divided section 205, and the radio wave shielding structures 210B are provided at the four corners of the divided section 205. As a result, microwaves are shielded around the entire circumference of the divided section 205, preventing microwave transmission between the multiple divided chambers. As shown in Figures 6 and 7, the radio wave shielding structure 210 is provided in two stages. This improves the microwave shielding performance compared to a single-stage structure.

[0035] As shown in Figures 5 and 8, rails 216 are provided on the inner wall 214, which is the inner surface of the heating chamber 201. The rails 216 support the divided section 205 from below and position the divided section 205 in a predetermined position inside the heating chamber 201. The divided section 205 can be placed on the rails 216 and is configured to be detachable from the heating chamber 201. This makes it possible to select between heating the object to be heated with the divided section 205 positioned in the heating chamber 201, or heating the object to be heated without the divided section 205 positioned in the heating chamber 201.

[0036] As shown in Figure 9, the radio wave shielding structure 210A is a non-contact type choke structure that does not come into contact with the upper surface of the rail 216. The divided section 205 is supported by contacting the inner wall 214 of the heating chamber 201 at a location different from that of the radio wave shielding structure 210A.

[0037] The rail 216 is made of an insulator such as resin or rubber. When both the radio wave shielding structure 210A and the inner wall 214 of the heating chamber 201 are made of metal, the insulation resistance is increased by providing the rail 216 as an insulator between them. Note that the rail 216 is not limited to an insulator and may be made of metal, in which case another insulator can be provided between the radio wave shielding structure 210A and the rail 216.

[0038] [1.2.2 Effects] According to the microwave heating apparatus 200 of the second embodiment described above, three divided chambers 228A to 228C are provided. With this configuration, the variations in heating conditions can be increased compared to the case with two divided chambers, enabling more flexible heating treatment.

[0039] Furthermore, the divided sections 205 and 206 are made of metal. With this configuration, microwaves, hot air, and steam do not penetrate the metal. Therefore, it is possible to change the degree of heating by the microwave, hot air, and steam heat sources for each divided chamber 228A to 228C. Also, by dividing the heating chamber 201, it becomes possible to heat food with microwaves, hot air, or steam in a small space, enabling highly efficient heating. A suitable heat source can be selected for each of the items to be heated 250A to 250C, enabling simultaneous heating of multiple items, faster heating at high temperatures, and energy-saving heating. Typical metals include stainless steel, aluminum, aluminum-plated steel sheets, and galvanized steel sheets. It is also possible to allow only hot air and steam to pass through by creating gaps (holes, slits, etc.) in the divided sections 205 and 206 that are too small for microwaves to penetrate.

[0040] Furthermore, an insulator (rail 216) is provided between the divided section 205 and the inner wall 214 of the heating chamber 201. With this configuration, by placing an insulator between the metals, the insulation resistance can be increased, and even if a strong electric field is generated between the metals during microwave heating, the possibility of discharge can be reduced. In addition, the insulator makes it possible to maintain a certain distance between the metals, further reducing the possibility of discharge. This improves safety (reduces the possibility of discharge). Typical insulators include resin, rubber, and wood.

[0041] Furthermore, the heating chamber 201 is divided in the height direction Z. With this configuration, by dividing the heating chamber 201 in the height direction Z, multiple items can be heated simultaneously, and furthermore, divided chambers 228A to 228C can be formed without restricting the dimensions of the heated items 250A to 250C in the width direction Y or depth direction X. This enables simultaneous heating of multiple items and relaxes the dimensional restrictions on the heated items 250A to 250C. This configuration is particularly effective when the heated items 250A to 250C are low in height but have a large horizontal surface area, such as a bento box.

[0042] Furthermore, the divided sections 205 and 206 have mounting surfaces 252 on which the objects to be heated 250B and 250C are placed. With this configuration, each of the divided sections 205 and 206 can be given the function of dividing the heating chamber 201 and the function of placing the objects to be heated 250B and 250C, thereby reducing the number of parts. This makes it possible to simplify the structure (improve ease of use and cleaning) and reduce costs.

[0043] Furthermore, a steam sensor 208 is provided in the divided chamber 228C. With this configuration, the steam sensor 208 installed in the divided chamber 228C can detect steam generated from the object to be heated 250C, allowing it to determine when the temperature of the object to be heated 250C has risen, making it possible to change the heating conditions or terminate the heating process. This enables uniform heating, heating to the appropriate temperature (mitigating overheating and underheating), and automatic cooking. Note that if a steam sensor is to be installed, it may be installed in each of the divided chambers 228A to 228C, and it is sufficient to install it in at least one of the divided chambers 228A to 228C.

[0044] Furthermore, a camera 207 is provided in the divided chamber 228C. With this configuration, the camera 207 installed in the divided chamber 228C detects the shape or surface color of the object to be heated 250C, allowing the progress of heating of the object to be heated 250C to be determined, and enabling the heating conditions to be changed or the heating process to be terminated. Also, by detecting the shape or surface color of the object to be heated 250C before heating begins, it is possible to set the heating conditions according to the initial temperature. This enables uniform heating, heating to the appropriate temperature (mitigation of overheating and underheating), and automatic cooking. Note that if cameras are to be installed, they may be installed in each of the divided chambers 228A to 228C, and it is sufficient to install them in at least one of the divided chambers 228A to 228C.

[0045] In Embodiment 2, two types of sensors, a camera 207 and a steam sensor 208, were provided in the same divided chamber 228C. However, the invention is not limited to this case, and different types of sensors may be provided in different divided chambers 228A to 228C. Specifically, the divided chamber may have a first divided chamber and a second divided chamber, with a first sensor provided in the first divided chamber and a second sensor of a different type from the first sensor provided in the second divided chamber. With this configuration, the temperature change of the object being heated due to heating will differ depending on the type of object being heated. Depending on the type of object being heated, the temperature difference between the interior and surface waves of the object, the amount of steam emitted from the object, the change in shape of the object being heated due to heating, and the change in color of the surface of the object being heated due to the temperature rise will differ. Therefore, the type of sensor that more accurately detects the heating state of the object being heated will differ depending on the type of object being heated. For this reason, by providing different types of sensors in multiple divided chambers, it becomes possible to more accurately detect the heating state of the object being heated by selecting the divided chamber in which the object being heated is placed according to the type of object being heated, making it possible to change the heating conditions or terminate the heating process. This enables uniform heating, heating to the appropriate temperature (mitigating overheating and underheating), and automated cooking.

[0046] Furthermore, the microwave radiation unit 204 radiates microwaves into the heating chamber 201 from the back surface 220 of the heating chamber 201. With this configuration, the shape and dielectric constant of the components of the heating chamber 201 in the front-to-back direction (depth direction X) differ greatly, but the shape and components of the sides are often almost the same. Therefore, the standing wave distribution within the heating chamber 201 is almost symmetrical, so if the symmetrical objects to be heated 250A to 250C are placed in the center of the heating chamber 201 in the left-to-right direction, the heating distribution of the objects to be heated 250A to 250C will be symmetrical. However, due to the symmetry of the shape and components of the heating chamber 201, the heating distribution in the front-to-back direction and the up-to-down direction (height direction Z) is often not symmetrical. Therefore, by providing a microwave radiation unit 204 on the back surface 220 of the heating chamber 201 and controlling the directivity of the microwaves radiated from the microwave radiation unit 204 into the heating chamber 201 in the vertical direction, the heating distribution in the vertical direction of the object to be heated 250A to 250C can be made uniform. This enables uniform heating.

[0047] Furthermore, the microwave radiation unit 204 is equipped with a rotating antenna 209. With this configuration, by controlling the directivity of the microwaves radiated by the rotating antenna 209 into the heating chamber 201 or the divided chambers 228A to 228C, it is possible to change the standing wave distribution in the heating chamber 201 or the divided chambers 228A to 228C. Therefore, it is also possible to control the heating distribution of the object to be heated 250A to 250C, thereby achieving uniform heating.

[0048] Furthermore, the divided sections 205 and 206 are detachable from the inner wall 214 of the heating chamber 201. With this configuration, any object to be heated that fits within the dimensions of the heating chamber 201 can be heated. In addition, removing the divided sections 205 and 206 makes cleaning easier. This improves ease of cleaning, allows for the formation of divided chambers according to the size of the object to be heated, and relaxes the dimensional limitations on the object that can be heated.

[0049] Furthermore, the divided sections 205 and 206 are provided with bidirectional radio wave shielding structures 210 and 211. This configuration makes it possible to concentrate microwaves in each of the divided chambers 228A to 228C that emit microwaves. By reducing the amount of microwaves propagating from one divided chamber to another, it becomes easier to set cooking conditions, and for example, it becomes possible to control the heating so that microwaves are not applied to the heated objects 250A to 250C that are not to be exposed to microwaves. This enables concentrated heating.

[0050] Furthermore, radio wave shielding structures 210 and 211 are provided on all four sides of the divided sections 205 and 206. This configuration improves the radio wave shielding performance of the divided sections 205 and 206.

[0051] Furthermore, different radio wave shielding structures 210A and 210B are provided in the corners and non-corner portions of the divided section 205, respectively. With this configuration, the electric field distribution often differs between the corners and non-corner portions (straight sections) of the divided section 205. Specifically, the area around the corners is greatly affected by microwaves reflected by the inner walls of adjacent heating chambers 201, and because microwaves propagate in a direction parallel to the edge in the radio wave shielding structure 210 of adjacent edges of the divided section 205, the microwaves propagating parallel to the two edges interfere with each other, resulting in a different electric field distribution than in the straight sections. Therefore, the optimal shape of the radio wave shielding structure 210 differs between the straight sections and the area around the corners. As a result, by providing different radio wave shielding structures 210A and 210B in the corners and non-corner portions, improved shielding performance can be achieved.

[0052] Furthermore, the radio wave shielding structures 210 and 211 are non-contact chokes. With this configuration, the non-contact shielding structure makes it easy to remove the divided sections 205 and 206. Compared to a contact-type shielding structure, it is no longer necessary to ensure that the inner wall of the heating chamber 201 and the metal parts of the divided sections 205 and 206 are in contact, thus simplifying the configuration. As a result, the removal of the divided sections 205 and 206 becomes easier, improving ease of cleaning. In addition, microwave leakage from the parts where the inner wall of the heating chamber 201 and the metal parts of the divided sections 205 and 206 are not in contact is prevented, reducing the possibility of discharge.

[0053] [1.2.3 Variations of radio wave shielding structures] [1.2.3.1 Configuration] Here, a modified example of the radio wave shielding structure 210 will be explained using Figures 10 to 17. Figures 10 to 17 are schematic cross-sectional views of the microwave shielding structure between the radio wave shielding structure 210 and the inner wall 214 of the heating chamber 201.

[0054] The radio wave shielding structure 210 according to Modification 1 has the cross-sectional shape shown in Figure 10 and shields radio waves in one direction. The radio wave shielding structure 210 shown in Figure 10 shields microwaves that are about to be incident in the downward direction Z1, but does not shield microwaves that are incident in the upward direction Z2.

[0055] The radio wave shielding structure 210 according to the modified example 2 has the cross-sectional shape shown in Figure 11 and shields radio waves in one direction. The radio wave shielding structure 210 shown in Figure 11 shields microwaves that are about to be incident in the downward direction Z1, but does not shield microwaves that are incident in the upward direction Z2.

[0056] The radio wave shielding structure 210 according to the modified example 3 has the cross-sectional shape shown in Figure 12 and shields radio waves in both directions. The radio wave shielding structure 210 shown in Figure 12 shields microwaves that are about to be incident in the downward direction Z1 and also shields microwaves that are about to be incident in the upward direction Z2.

[0057] The radio wave shielding structure 210 according to Modification 4 has the cross-sectional shape shown in Figure 13 and shields radio waves in both directions. The radio wave shielding structure 210 shown in Figure 13 shields microwaves attempting to enter in the downward direction Z1 and also shields microwaves attempting to enter in the upward direction Z2.

[0058] The radio wave shielding structure 210 according to Modification 5 has the same shape as the radio wave shielding structure 210 of Modification 1 (Figure 10), as shown in Figure 14, and is a unidirectional radio wave shielding structure. The radio wave shielding structure 210 shown in Figure 14 further has a dielectric cover 218.

[0059] The radio wave shielding structure 210 according to Modification 6 has the same shape as the radio wave shielding structure 210 of Modification 2 (Figure 11), as shown in Figure 15, and is a unidirectional radio wave shielding structure. The radio wave shielding structure 210 shown in Figure 15 further has a dielectric cover 218.

[0060] The radio wave shielding structure 210 according to Modification 7 has the same shape as the radio wave shielding structure 210 of Modification 3 (Figure 12), as shown in Figure 16, and is a radio wave shielding structure in both directions. The radio wave shielding structure 210 shown in Figure 16 further has a dielectric cover 218.

[0061] The radio wave shielding structure 210 according to Modification 8 has the same shape as the radio wave shielding structure 210 of Modification 4 (Figure 13), as shown in Figure 17, and is a radio wave shielding structure in both directions. The radio wave shielding structure 210 shown in Figure 17 further has a dielectric cover 218.

[0062] [1.2.3.2 Effects] According to modifications 1, 2, 5, and 6, the divided section 205 has a unidirectional radio wave shielding structure 210. With this configuration, for example, in a non-contact type radio wave shielding structure, the radio wave shielding performance varies greatly depending on the distance between the metals facing each other from the divided chamber 205 to the resonant space of the radio wave shielding structure 210. Thus, because the radio wave shielding performance of the divided section 205 is directional, it is possible to either radiate microwaves into one divided chamber to propagate them to other divided chambers, or concentrate microwaves within one divided chamber. This makes it easier to perform concentrated heating and allows multiple divided chambers to be microwaved at once.

[0063] According to modifications 3, 4, 7, and 8, the divided portion 205 has a radio wave shielding structure 210 in both directions. This configuration provides the same effects as in embodiment 2.

[0064] According to modifications 5-8, the radio wave shielding structure 210 has a dielectric cover 218. In this configuration, the non-contact type radio wave shielding structure 210 is often composed of a periodic metal structure. Also, the transmission length of the resonant space of the shielding structure is often an integer multiple of 1 / 4 of the wavelength of the microwave to be shielded. Therefore, the radio wave shielding structure 210 is made of bent metal plates, and foreign matter such as food residue and water droplets can get inside. When foreign matter with a high dielectric constant gets inside, the microwave distribution in the resonant space of the radio wave shielding structure 210 changes, and the shielding performance may decrease compared to normal conditions without foreign matter. Also, since a strong electric field is likely to be generated between the metal parts of the radio wave shielding structure 210, the possibility of discharge and smoke generation increases when food residue gets inside. Therefore, by placing a dielectric cover 218 of a dielectric with a low dielectric constant, such as resin, on the shielding structure, it is possible to reduce the decrease in shielding performance and the possibility of discharge and smoke generation. It is also possible to improve cleaning performance. This stabilizes shielding performance (improves safety), prevents the insertion of foreign matter, reduces discharge (improves safety), and improves the insulation resistance of metal parts. Furthermore, by maintaining a certain distance between the inner wall 214 of the heating chamber 201 and the radio wave shielding structure 210, discharge can be reduced (improves safety) and cleaning can be improved. Typical dielectric materials include ceramics, resins, and glass.

[0065] [1.3 Embodiment 3] [1.3.1 Configuration] Figure 18A is a schematic side view of an example configuration of a microwave heating device 300 according to Embodiment 3. The microwave heating device 300 shown in Figure 18A comprises a heating chamber 301, a microwave generating unit 303, a microwave radiating unit 304, a dividing unit 305, a hot air heating means 315, a radiant heating means 316, a steam heating means 317, and microwave sensors 318A and 318B.

[0066] The heating chamber 301 shown in Figure 18A is divided in the height direction Z by a dividing section 305, forming two divided chambers 328A and 328B. The object to be heated 302A is placed in the lower divided chamber 328A, and the object to be heated 302B is placed in the upper divided chamber 328B.

[0067] The microwave radiation unit 304 is located on the rear side of the heating chamber 301 and has a rotating antenna 309. The rotating antenna 309 radiates microwaves, for example, toward the upper divided chamber 328B.

[0068] The hot air heating means 315 is a component for heating with hot air. The hot air heating means 315 includes, for example, a convection heater and a fan. The hot air heating means 315 is installed on the rear side of the heating chamber 301 so as to blow hot air toward the lower divided chamber 328A.

[0069] The radiant heating means 316 is a component for heating by radiation. The radiant heating means 316 has, for example, an infrared heater. The radiant heating means 316 is installed on the top side of the heating chamber 301 so as to supply radiant heat toward the upper divided chamber 328B.

[0070] The steam heating means 317 is a component for heating by steam. The steam heating means 317 includes, for example, a water reservoir for steam generation and a heater. The steam heating means 317 is provided on the rear side of the heating chamber 301 so as to blow steam toward the upper divided chamber 328B.

[0071] Microwave sensors 318A and 318B are sensors that detect microwaves. Two microwave sensors 318A and 318B are provided in the heating chamber 301 shown in Figure 18A. Microwave sensor 318A detects microwaves in the lower divided chamber 328A, and microwave sensor 318B detects microwaves in the upper divided chamber 328B.

[0072] In the lower divided chamber 328A, the object to be heated 302A is placed on the mounting surface 319A. The mounting surface 319A is a plate-shaped member that constitutes the bottom surface of the heating chamber 1. In the upper divided chamber 328B, the object to be heated 302B is placed on the mounting surface 319B. The mounting surface 319B is a plate-shaped member that constitutes the upper surface of the divided section 305. The mounting surfaces 319A and 319B are each made of dielectric material.

[0073] The divided portion 305 forms a recess 320 below the mounting surface 319B. A metal 321 is placed in the recess 320. By placing the metal 321, the microwave distribution around the lower part of the object to be heated 302B can be changed.

[0074] The divided section 305 further includes a radio wave shielding structure 310. Details of the radio wave shielding structure 310 will be explained with reference to Figures 19 and 20.

[0075] Figure 19 is a top view of the divided section 305, and Figure 20 is a cross-sectional view of the divided section 305 as seen from the front.

[0076] As shown in Figure 19, the radio wave shielding structure 310 has two types of radio wave shielding structures 310A and 310B. Radio wave shielding structure 310A is provided on one side of the divided section 310 that is closer to the door 325 and faces the door glass 326 that constitutes the door 325. Radio wave shielding structure 310B is provided on the three sides of the divided section 310 other than the side on which radio wave shielding structure 310A is provided. Radio wave shielding structure 310A has a different structure from radio wave shielding structure 310B, for example, its pitch and width are different from the choke structure of radio wave shielding structure 310B.

[0077] As shown in Figures 19 and 20, rails 323 are provided on the inner walls 312 on both sides of the heating chamber 310. The rail 323 shown in Figure 20 has an inclined surface 324 that supports the divided portion 305. An inclined surface 325 corresponding to the inclination of the inclined surface 324 is formed on the lower surface of the divided portion 305. By positioning the divided portion 305 with the inclined surface 325 of the divided portion 305 in contact with the inclined surface 324 of the rail 323, the divided portion 305 can be positioned (centered) toward a predetermined position (center position) in the Y direction when it is placed in the heating chamber 301.

[0078] An example of the operation of the rotating antenna 309 shown in Figure 18A will be explained using Figures 21 to 23.

[0079] The rotating antenna 309 shown in Figure 21 is controlled to rotate within a rotation range R1, with a rotation axis 321 located approximately at the center of the heating chamber 301. The rotation range R1 covers only the upper division chamber 328B. The rotating antenna 309 radiates microwaves toward the upper division chamber 328B, but does not radiate microwaves toward the lower division chamber 328A.

[0080] The rotating antenna 309 shown in Figure 22 is controlled to rotate within a rotation range R2, with a rotation axis 321 located approximately in the center of the heating chamber 301. The rotation range R2 covers only the lower division chamber 328A. The rotating antenna 309 radiates microwaves toward the lower division chamber 328A, but does not radiate microwaves toward the upper division chamber 328B.

[0081] The rotating antenna 309 shown in Figure 23 is controlled to rotate within a rotation range R3, around a rotation axis 321 located approximately in the center of the heating chamber 301. The rotation range R3 is a 360-degree rotation range, covering both the divided chambers 328A and 328B. In the first rotation range, the rotating antenna 309 radiates microwaves toward the lower divided chamber 328A, and in the second rotation range, it radiates microwaves toward the upper divided chamber 328B.

[0082] [1.3.2 Effects] The microwave heating device 300 of the above-described embodiment 3 further comprises a hot air heating means 315, a radiant heating means 316, and a steam heating means 317. With this configuration, by using hot air, radiant heating, or steam heating in combination with microwave heating, it becomes possible to cook the objects to be heated 302A and 302B in a manner more suitable for them, improving the quality of the cooked food and increasing the range of dishes that can be cooked. For example, for objects to be heated that require both an overall temperature increase and browning of the surface, such as gratin, the combination of microwave heating and radiant heating is effective. Also, for objects to be heated that require both an overall temperature increase and prevention of drying, such as Chinese steamed buns, the combination of microwave heating and steam heating is effective. Furthermore, for objects to be heated that have a large volume and require both an overall temperature increase and overall browning, such as roast beef, the combination of microwave heating and hot air heating is effective. Furthermore, it is not necessary to provide all of the hot air heating means 315, radiant heating means 316, and steam heating means 317; it is sufficient to provide at least one of each means in at least one divided chamber.

[0083] Furthermore, of the multiple divided chambers 328A and 328B, only one of them has the function of heating the object to be heated (Figures 21 and 22). With this configuration, by placing the object to be heated in one divided chamber, it is possible to change the heating conditions for each object. In addition, by placing the object to be heated in a divided chamber of the multiple divided chambers 328A and 328B that is the same size as the object to be heated and heating it, highly efficient heating becomes possible. This enables faster heating, higher temperature heating, and energy-saving heating. The same effect is obtained even if multiple objects to be heated are placed in one divided chamber. Moreover, the effect is obtained even if the size of the divided chamber in which the object to be heated is smaller than the heating chamber 301 before division, so the effect is obtained even if the size of the divided chamber is not the same as the size of the object to be heated.

[0084] Furthermore, of the multiple divided chambers 328A and 328B, two divided chambers 328A and 328B have the function of heating the objects to be heated 302A and 302B (Figure 23). With this configuration, by placing the objects to be heated 302A and 302B in the two divided chambers 328A and 328B respectively, it is possible to change the heating conditions for each object to be heated 302A and 302B. Moreover, while conventional equipment required heating each object to be heated 302A and 302B individually, it is possible to heat multiple objects to be heated 302A and 302B simultaneously. In addition, by placing the objects to be heated 302A and 302B in divided chambers 328A and 328B that are the same size as the objects to be heated 302A and 302B and heating them, highly efficient heating becomes possible. This allows for the selection of a suitable heat source for each object to be heated 302A, 302B, enabling simultaneous heating of two items, faster heating at high temperatures, and energy-saving heating. The same effect can be achieved even if multiple objects to be heated 302A, 302B are placed in a single divided chamber 328A, 328B. Furthermore, the effect is achieved even if the size of the divided chamber 328A, 328B containing the objects to be heated 302A, 302B is smaller than the heating chamber 301 before division; therefore, the effect is not limited to the size of the divided chamber 328A, 328B being the same size as the objects to be heated 302A, 302B.

[0085] Furthermore, the mounting surface 319B of the divided portion 305 is made of a dielectric material, and the divided portion 305 forms a recess 320 below the mounting surface 319B. With this configuration, by providing a recess 320 below the mounting surface 319B, a space can be created that allows microwaves to wrap around to the underside of the object to be heated 302B. If the object to be heated 302B is placed on a metal plate, the electric field strength generated during microwave heating becomes zero at the metal surface, so the contact surface between the object to be heated 302B and the metal will be less heated. Therefore, by providing a space below the mounting surface 319B made of a dielectric material, it is possible to strengthen the heating on the mounting surface 319B, which is the mounting surface of the object to be heated 302B. This makes it possible to achieve uniform heating. Typical dielectric materials include ceramics, resins, and glass.

[0086] Furthermore, a metal 321 is provided in the recess 320. With this configuration, the metal 321 reflects microwaves, so the surrounding microwave distribution becomes different from the microwave distribution when the metal 321 is not present. Therefore, depending on the shape and position of the metal 321, it is possible to make the heating distribution of the object to be heated 302B uniform. This enables uniform heating. The metal 321 is effective whether it is in the shape of a plate, block, or rod. By making any dimension of the metal 321 an integer multiple of 1 / 4 wavelength of a microwave, it can be made to act as an antenna, making it possible to change the microwave distribution around the metal 321 more significantly. Any dimension of the metal 321 refers to the dimension of one side of the metal 321, or the dimension between surfaces of the metal 321.

[0087] Furthermore, the rotating antenna 309 is controlled to rotate within a predetermined range. With this configuration, by moving the rotation angle of the rotating antenna 309 back and forth within the range that radiates microwaves into one divided chamber, it becomes possible to concentrate the heating of the object to be heated in one divided chamber and to heat while changing the standing wave distribution in the divided chamber determined by the rotation angle, thereby improving the uniformity of heating of the object to be heated. As a result, microwaves can be concentrated on the object to be heated in the target divided chamber, and the object to be heated can be heated uniformly.

[0088] Furthermore, radio wave shielding structures 310 are provided on all four sides of the divided section 305. This configuration improves the radio wave shielding performance of the divided section 305.

[0089] Furthermore, a radio wave shielding structure 310A (first radio wave shielding structure) is provided on the first side of the divided section 305, and a radio wave shielding structure 310B (second radio wave shielding structure) different from the first side of the divided section 305 is provided on the second side different from the first side of the divided section 305. With this configuration, the shape of the inner wall of the heating chamber 301 and the dielectric constant of its components are often different. For example, there is a dielectric such as a glass plate or resin plate on the door 325 side, and an antenna that radiates microwaves into the heating chamber 301 on the side with the power supply unit. Therefore, the optimal shape of the shielding configuration differs depending on the shape of the inner wall 312 of the heating chamber 301 and the dielectric constant of its components. As a result, the radio wave shielding performance can be improved by designing the radio wave shielding structure 310 according to the side of the divided section 305.

[0090] Furthermore, the first side of the divided section 305 on which the radio wave shielding structure 310A is provided is the side of the divided section 305 facing the door 325. In this configuration, a door glass 326 or a resin plate is often installed on the side of the door 325 facing the heating chamber 301. Since microwave wavelength compression occurs within the dielectric, the microwave distribution between the inner wall of the heating chamber 301 and the divided section 305 differs between the side facing the door 325 and the sides not facing the door 325. Therefore, if the shielding performance on the side facing the door 325 is to be equivalent to that on the other sides, it is advisable to make the radio wave shielding structure 310A on the side facing the door 325 different from the radio wave shielding structure 310B on the other sides. If the distance between the radio wave shielding structure 310 and the metal surface on the door 325 side is the same as the distance between the radio wave shielding structure 310 and the metal surface on the other sides, it is advisable to shorten the microwave transmission length in the resonant space of the radio wave shielding structure 310, taking into account the wavelength compression within the dielectric. Furthermore, in order to prevent mechanical interference, if the distance between the radio wave shielding structure 310 and the metal surface on the door 325 side is greater than the wavelength compression within the dielectric, it is advisable to increase the microwave transmission length within the resonant space of the radio wave shielding structure 310. This makes it possible to improve the radio wave shielding performance by making the radio wave shielding structure 310 on the door 325 side of the divided section 305 different from the radio wave shielding structure 310 on the other sides.

[0091] Furthermore, the side on which the radio wave shielding structure 310A is provided is not limited to the side of the divided section 305 on the door 325 side, but may also be provided on the side of the divided section 305 facing the microwave radiation section 304 (the back side). In other words, the first side of the divided section 305 on which the radio wave shielding structure 310A is provided may be the side of the divided section 305 closer to the microwave radiation section 304. With this configuration, the microwave energy density is higher in the vicinity of the microwave radiation section 304, and there is a high possibility that a strong electric field will be generated between the metal of the divided section 305 and the rotating antenna 309, causing a discharge. Therefore, if the radio wave shielding structure of the divided section 305 in the vicinity of the microwave radiation section 304 is configured to be less prone to discharge than the radio wave shielding structures in other parts, the possibility of discharge can be reduced. For example, the distance between the rotating antenna 309 and the radio wave shielding structure 300 may be made longer than the distance between the other inner walls 312 (side walls) of the heating chamber 301 and the radio wave shielding structure 300, thereby differentiating the radio wave shielding structure. Furthermore, rounding the end faces of each metal in the radio wave shielding structure 310 or the rotating antenna 309 is also effective. Additionally, attaching an insulator to the end faces of each metal in the radio wave shielding structure 310 or the rotating antenna 309 to increase the insulation resistance of the metal surface is also effective. This improves radio wave shielding performance and enhances safety by reducing discharge.

[0092] Furthermore, the divided section 305 divides the heating chamber 301 in the height direction Z, and the inner wall 312 of the heating chamber 301 has an inclined surface 324 for centering the divided section 305 toward the center of the heating chamber 301. With this configuration, if the inclined surfaces are not parallel, they will come into contact at a point or along a line, making them prone to slipping. However, if the inclined surfaces 324 and 325 are parallel, they will come into contact over a wide area, making them less likely to slip from one another. Therefore, by providing the divided section 305 and the rail 323 with inclined surfaces 324, the divided section 305 can slide due to its own weight until the inclined surfaces 324 and 325 become parallel, thereby stabilizing the position of the divided section 305 relative to the inner wall of the heating chamber 301. This stabilizes the shielding performance of the divided section 305.

[0093] Furthermore, microwave sensors 318A and 318B are installed in the divided chambers 328A and 328B. With this configuration, various controls can be performed using the detection results of the microwave sensors 318A and 318B. These controls will be explained using Figures 24 to 32.

[0094] [1.3.3 Examples of microwave sensor applications] Figure 24 is a schematic diagram illustrating an example of using a microwave sensor with a heating device 300 according to Embodiment 3. As shown in Figure 24, the heating device 300 includes a microwave generating unit 350 for generating microwaves W1, a microwave radiating unit 351 for radiating the microwaves generated by the microwave generating unit 350 onto an object to be heated 302A in a heating chamber 301, and a heating unit 352 for heating the object to be heated 302A by means other than microwaves. The microwave generating unit 350 is connected to a control unit 311. The heating unit 352 is a heating source other than a microwave heating source (heater), such as a radiant heating source, a hot air convection heating source, or a steam heating source.

[0095] The microwave generator 350 and microwave radiator 351 shown in Figure 24 combine the functions of radiating microwaves and detecting the radiated microwaves, and thus also function as microwave sensors. The microwave sensors are built into, for example, the microwave radiator 351 or the microwave generator 350. However, the configuration is not limited to this case; as in the example configuration of the heating device 300 shown in Figure 18A, the microwave generator 303 and microwave radiator 304 and the microwave sensors 318A and 318B may be separate components, and the same control can be applied.

[0096] The control unit 311 detects the power of the reflected wave over time using a microwave sensor, determines the state of the object to be heated 302A based on the change in the power of the reflected wave over time, and controls the radio waves irradiated by the microwave radiation unit 351 based on the result of the determination.

[0097] The control unit 311 may terminate the heating process by controlling the radio waves irradiated by the microwave radiator 351 if, for example, the state of the object to be heated 302A is in the state of having finished heating, based on the change in the power of the reflected wave over time.

[0098] The operation of the control unit 311 in this case will be explained with reference to the flowchart shown in Figure 25. The control unit 311 starts the heating process (S31), detects the reflected wave power using the microwave sensor (S32), and determines the state of the object to be heated 302A based on the change in the reflected wave power over time (S33). If the determination shows that the state of the object to be heated 302A is the state of heating completion (YES in S34), the control unit 311 terminates the heating process (S35).

[0099] For example, consider the case where the object to be heated 302A is water and the heating process causes it to boil. In this case, the state at the end of heating is that the object to be heated 302A is boiling. Figure 26 is an explanatory diagram for detecting the state change of the object to be heated 302A, showing the case when the object to be heated 302A is boiling. When the object to be heated 302A is boiling, the liquid level of the object to be heated 302A rises and falls, so the liquid level changes between h1 and h1+d1. When the liquid level is h1+d1, microwave W1 is irradiated onto the object to be heated 302A, but when the liquid level is h1, the microwave W1 does not hit the object to be heated 302A but hits the wall of the heating chamber 301 and is reflected, and the reflected wave W2 is detected by the microwave sensor. Therefore, based on the time-dependent change in reflected wave power detected by the microwave sensor, it is possible to determine whether the heated object 302A is boiling or not.

[0100] The control unit 311 may, for example, change the heating conditions by controlling the radio waves irradiated by the microwave radiator 351 if the state of the object to be heated 302A is in a state of condition change based on the time-dependent change in the power of the reflected wave. The change in heating conditions may be, for example, a switch from heating by the microwave generator 350 to heating by the heating unit 352. The change in heating conditions is not particularly limited and may be a change in at least one of the power, frequency, and phase difference of the radio waves generated by the microwave generator 350.

[0101] The operation of the control unit 311 in this case will be explained with reference to the flowchart shown in Figure 27. The control unit 311 starts the heating process (S41), detects the reflected wave power using the microwave sensor (S42), and determines the state of the object to be heated 302A based on the change in reflected wave power over time (S43). If the determination shows that the state of the object to be heated 302A is in a state where the conditions should be changed (YES in S44), the control unit 311 changes the heating conditions (S45).

[0102] Examples of changes in the conditions of the heated object 302A include changes in shape due to expansion, a local increase in dielectric constant due to melting, a local increase in dielectric constant due to thawing, changes in position, and a decrease in dielectric constant due to drying.

[0103] Figure 28 is an explanatory diagram for detecting changes in the state of the object being heated 302A, showing the case where a change in shape occurs due to expansion of the object being heated 302A. When the object being heated 302A expands, its height changes from h2 to h2+d2. When the height of the object being heated 302A is h2, the microwave W1 does not hit the object being heated 302A but hits the wall of the heating chamber 301 and is reflected, and is detected as a reflected wave W2 by the microwave sensor. When the height of the object being heated 302A is h2+d2, the microwave W1 is irradiated onto the object being heated 302A and absorbed. Therefore, based on the change in reflected wave power detected by the microwave sensor over time, it is possible to determine whether the object being heated 302A has changed shape due to expansion.

[0104] Figure 29 is an explanatory diagram for detecting a change in the state of the heated object 302A, showing the case where a localized increase in dielectric constant occurs due to the melting of the heated object 302A. The power of microwaves absorbed by a dielectric is proportional to the relative permittivity of the dielectric. After a melted portion 360 occurs in the heated object 302A, the power of the radio waves absorbed by the melted portion 360 increases, and the power of the reflected wave W2 decreases. Therefore, based on the change in reflected wave power over time detected by the microwave sensor, it is possible to determine whether the heated object 302A has partially melted and a localized increase in dielectric constant has occurred.

[0105] Figure 30 is an explanatory diagram for detecting a change in the state of the heated object 302A, showing a case where a localized increase in dielectric constant occurs due to the thawing of the heated object 302A. This change in state occurs when the heated object 302A is a frozen food and is thawed by the heat treatment. The power of microwaves absorbed by a dielectric is proportional to the relative permittivity of the dielectric. After a thawed portion 362 is formed in the heated object 302A, the power of the radio waves absorbed in the thawed portion 362 increases, and the power of the reflected wave W2 decreases. Therefore, based on the change in reflected wave power detected by the microwave sensor over time, it is possible to determine whether the state of the heated object 302A is such that it is partially thawed and a localized increase in dielectric constant has occurred.

[0106] Figure 31 is an explanatory diagram for detecting changes in the state of the object being heated 302A, showing the case where the position of the object being heated 302A changes. For example, during the heating process, a part of the object being heated 302A may burst, causing the object to move within the heating chamber 301 and changing its position. For example, when the object being heated 302A is in its initial position, the microwave W1 does not hit the object being heated 302A but hits the wall of the heating chamber 301 and is reflected, and is detected as a reflected wave W2 by the microwave sensor. On the other hand, for example, when the object being heated 302A moves from its initial position, the microwave W1 is irradiated onto the object being heated 302A and absorbed. Therefore, based on the change in the reflected wave power detected by the microwave sensor over time, it is possible to determine whether the state of the object being heated 302A has changed due to movement.

[0107] Figure 32 is an explanatory diagram for detecting a change in the state of the heated object 302A, showing the case where the dielectric constant decreases due to drying of the heated object 302A. The power of microwaves absorbed by a dielectric is proportional to the relative permittivity of the dielectric. After a dry portion 364 is formed in the heated object 302A, the power of the radio waves absorbed by the dry portion 364 decreases, and the power of the reflected wave W2 increases. Therefore, based on the change in reflected wave power over time detected by the microwave sensor, it is possible to determine whether the heated object 302A has partially dried and its dielectric constant has decreased.

[0108] In this embodiment as well, reflectance may be used instead of reflected wave power.

[0109] As described above, in this embodiment, the control unit 311 has the function of a state detection means for detecting a change in the state of the object to be heated 302A from a change in reflected wave power or reflectance, and the function of a control means for controlling the microwave according to the detected state. The control unit 311 detects a change in the state of the object to be heated 302A (for example, boiling, swelling, melting, thawing, bursting, drying) from a change in reflected wave power or reflectance, and changes the heating conditions or terminates heating. Here, microwave control includes microwave irradiation, stopping microwave irradiation, changing the microwave frequency, adjusting the microwave output, etc.

[0110] As the heating of the object 302A progresses, the object 302A may undergo shaking and changes in shape, such as boiling and swelling, as well as rapid changes in dielectric constant, such as melting and drying. These changes in the state of the object 302A alter its micro-absorption characteristics, resulting in changes to the reflected wave power or reflectance. Changing the heating conditions or ending heating when the state of the object 302A changes is effective in mitigating over- or under-heating and achieving a high-quality finish. Conventionally, cooking involved pre-determining the time for changing heating conditions and ending heating, or measuring the temperature inside the heating chamber with a thermocouple to change heating conditions and end heating. However, if the weight, container, or initial temperature of the object 302A differed from expectations, over- or under-heating was likely, preventing the realization of high-quality automatic cooking. In this embodiment, however, detecting the state of the object 302A enables high-quality automatic cooking. Furthermore, if information about the object being heated 302A, such as its weight, current temperature, and type, can be utilized, the accuracy of detecting changes in the state of the object being heated 302A can be further improved. In addition, by calculating auxiliary information such as reflectance from the relationship between the detected reflected wave power and the incident wave (irradiated wave) power and using it as feedback information, accuracy can be further improved.

[0111] Furthermore, when determining the state using reflected wave power, it is acceptable to use only the reflected wave power with respect to frequency, or to use representative values ​​of the reflected wave power for multiple frequencies (e.g., mean, maximum, minimum, mode, median, central value, etc.). In addition, when determining the state using reflected wave power, the state may be determined by whether the rate of change or standard deviation of the reflected wave power or reflectance per unit time exceeds a predetermined threshold.

[0112] [1.3.4 Modified Examples of Embodiment 3] Figure 18B is a schematic side view of an example configuration of a microwave heating apparatus 300 according to a modified example of Embodiment 3.

[0113] The microwave heating apparatus 300 shown in Figure 18B comprises a magnetron 370, a waveguide 372, and a microwave sensor 374.

[0114] The magnetron 370 is an example of a microwave generator and supplies microwaves to the waveguide 372. The waveguide 372 is a component that propagates the microwaves generated by the magnetron 370 and is coupled to the microwave radiator 304 and the rotating antenna 309. The microwave sensor 374 is a sensor that detects microwaves propagating through the waveguide 372.

[0115] With the above configuration, the microwaves generated by the magnetron 370 are supplied to the microwave radiation unit 304 and the rotating antenna 309 through the waveguide 372, allowing the rotating antenna 309 to radiate microwaves towards the division chambers 328A and 328B. By using the microwave sensor 374, it is also possible to perform control similar to the "Example of Microwave Sensor Use" explained with Figures 24 to 32.

[0116] A configuration having a magnetron 370 and a waveguide 372, as shown in Figure 18B, may be applied in all embodiments.

[0117] [1.4 Embodiment 4] [1.4.1 Configuration] Figure 33 is a schematic top view of an example configuration of a microwave heating apparatus 400 according to Embodiment 4. The microwave heating apparatus 400 shown in Figure 33 comprises a heating chamber 401, a microwave generating unit 403, a microwave radiating unit 404, and dividing units 405A and 405B.

[0118] The heating chamber 401 shown in Figure 33 is divided into three partitioned chambers 428A, 428B, and 428C by two partitioned sections 405A and 405B. Partitioned section 405A extends in the depth direction Y to divide the heating chamber 301 in the width direction X. Partitioned section 405B extends in the width direction X to further divide the space on one side of the heating chamber 301 divided by partitioned section 405A in the depth direction Y. In the example shown in Figure 33, the object to be heated 402 is placed in partitioned chamber 428B.

[0119] The dividing section 405A is made of a microwave-shielding material, such as metal. On the other hand, the dividing section 405B is made of a microwave-transmitting material, such as resin, i.e., a dielectric. As a result, microwaves are shielded between dividing chamber 428A and dividing chambers 428B and 428C by the dividing section 405A, while microwaves are not shielded between dividing chamber 428B and dividing chamber 428C and are transmitted through without being shielded by the dividing section 405B.

[0120] The divided section 405A further has radio wave shielding structures 410A and 410B at the ends facing the heating chamber 401. In this embodiment, the radio wave shielding structures 410A and 410B employ different types of structures. For example, depending on the distance between the divided section 405A and the inner wall of the heating chamber 401, the radio wave shielding structure 410A on the side not close to the radio wave radiating section 404 is a non-contact type radio wave shielding structure, and the radio wave shielding structure 410B on the side close to the radio wave radiating section 404 is a contact type radio wave shielding structure.

[0121] The microwave radiation unit 404 is located on the side of the heating chamber 401 and has a rotating antenna 409. The rotating antenna 409 radiates microwaves, for example, toward the division chamber 428B and the division chamber 428A, respectively. Microwaves radiated toward the division chamber 428B can pass through the division section 405B and enter the division chamber 428C.

[0122] As shown in Figure 33, when the object to be heated 402 is placed in the divided chamber 428B and no object to be heated is placed in the other divided chambers 428A and 428C, the microwave radiating unit 404 is controlled to radiate microwaves toward the divided chamber 428B, for example, with the rotating antenna 409 stopped. As a result, the rotating antenna 409 always radiates microwaves toward the divided chamber 428B. On the other hand, when another object to be heated is placed in the divided chamber 428A in addition to the object to be heated 402 in the divided chamber 428B, the microwave radiating unit 404 is controlled to radiate microwaves while continuously rotating the rotating antenna 409, for example. In this case, the microwave radiating unit 404 radiates microwaves toward the divided chamber 428A in a first rotation range and radiates microwaves toward the divided chamber 428B in a second rotation range. This allows the object to be heated 402, which is placed in the divided chamber 428B, and the object to be heated, which is placed in the divided chamber 428A, to be heated alternately, enabling the heating of multiple items.

[0123] [1.4.2 Effects] The microwave heating device 400 of the above-described embodiment 4 has the function of heating the object to be heated 402 in only one of the divided chambers 428A to 428C (for example, divided chamber 428B). With this configuration, by placing the object to be heated 402 in one divided chamber, it is possible to change the heating conditions for each object to be heated 402. Furthermore, by heating the object to be heated 402 in a divided chamber of the multiple divided chambers 428A to 428C that is the same size as the object to be heated 402, highly efficient heating becomes possible. This enables faster heating, higher temperature heating, and energy-saving heating. Note that the same effect is obtained even if multiple objects to be heated 402 are placed in one divided chamber. Note that the effect is obtained even if the size of the divided chamber in which the object to be heated 402 is placed is smaller than the heating chamber 401 before division, so the effect is obtained even if the size of the divided chamber is not the same as the size of the object to be heated 402.

[0124] Furthermore, the divided section 405B is made of a dielectric material. With this configuration, microwaves penetrate the dielectric, but hot air and steam do not. Therefore, it is possible to vary the degree of heating by heating sources other than microwaves in each divided chamber. In addition, by dividing the heating chamber 401, it becomes possible to heat food with hot air and steam in a smaller space, enabling highly efficient heating. This allows for the selection of a heating source suitable for each object to be heated, enabling simultaneous heating of multiple items, faster and higher-temperature heating, and energy-saving heating. Typical dielectric materials include ceramics, resins, and glass.

[0125] Furthermore, the dividing section 405A divides the heating chamber 401 in the depth direction X. With this configuration, by dividing the heating chamber 401 in the depth direction Y, it becomes possible to heat multiple items simultaneously, and moreover, compared to before the division, the divided chamber can be formed without restricting the height direction Z or width direction Y dimensions of the object to be heated 402. This enables simultaneous heating of multiple items and relaxes the dimensional restrictions on the object to be heated 402 that can be heated. This configuration is particularly effective when the object to be heated placed in the divided chamber 428A has a large width direction Y dimension, such as pasta.

[0126] Furthermore, the microwave radiation unit 404 radiates microwaves into the heating chamber 401 from its side. With this configuration, microwave ovens often have a door at the front, allowing the heated object 402 to be removed from the front. Perforated metal is used on the flat metal surface of the door so that the inside of the heating chamber 401 can be seen from the outside of the door. To increase the airtightness of the heating chamber 401 and improve ease of cleaning, a dielectric material such as a transparent glass plate or resin plate is placed on the heating chamber 401 side of the perforated metal. Therefore, the shape of the wall surface and the dielectric constant of the components differ greatly in the front-to-back direction of the heating chamber 401, so the heating distribution of the heated object 402 often differs greatly in the front-to-back direction. Therefore, by providing a microwave radiation unit 404 (power supply unit) on the side of the heating chamber 401 and controlling the directivity of the microwaves radiated from the microwave radiation unit 404 into the heating chamber 401 in the front-to-back direction, the heating distribution of the heated object 402 in the front-to-back direction can be made uniform. Furthermore, by providing a microwave radiation unit 404 on the side of the heating chamber 401 and controlling the directionality of the microwaves radiated from the microwave radiation unit 404 into the heating chamber 401 in the vertical direction, the heating distribution of the object to be heated 402 in the vertical direction can be made uniform. This enables uniform heating.

[0127] Furthermore, the microwave radiating unit 404 has the function of radiating microwaves while the rotating antenna 409 is stopped. With this configuration, by stopping the rotating antenna 409 and concentrating the microwaves radiated into one divided chamber (for example, divided chamber 428B), it becomes possible to concentrate the microwave heating of the object to be heated 402 in that divided chamber 428B. This enables concentrated heating. In practice, if the rotating antenna 409 is fixed in one direction and microwave heating is performed for a long time, the standing wave distribution in the heating chamber 401 becomes fixed, making it easy for discharge and heating unevenness to occur. To suppress this, the stopping operation and rotation operation of the rotating antenna 409 may be combined. If the shape of the rotating antenna 409 is branched and capable of radiating microwaves in two directions, it becomes possible to simultaneously concentrate the microwave heating of objects to be heated in two divided chambers.

[0128] Furthermore, the microwave radiating unit 404 has the function of radiating microwaves while continuously rotating the rotating antenna 409. With this configuration, by continuously rotating the rotating antenna 409 to heat the object to be heated, it becomes possible to heat the object while changing the standing wave distribution in the divided chambers 428A to 428C, which is determined by the rotation angle of the rotating antenna 409, thereby improving the uniformity of heating. In addition, if the divided chamber 428A to 428C that radiates microwaves more strongly changes depending on the rotation angle of the rotating antenna 409, it becomes possible to heat the objects to be heated in multiple divided chambers 428A to 428C simultaneously. This makes it possible to achieve uniform heating and simultaneous heating of multiple items.

[0129] Furthermore, the radio wave shielding structures 410A and 410B include a contact-type radio wave shielding structure 410B (first radio wave shielding structure) and a non-contact-type radio wave shielding structure 410A (second radio wave shielding structure). With this configuration, the type of radio wave shielding structure 410A and 410B can be selected to be either non-contact or contact-type depending on the positional relationship between the inner wall of the heating chamber 401 and the divided section 405A. In the part where the plate-shaped divided section 405A is held by providing irregularities on the inner wall of the heating chamber 401, the divided section 405A and the heating chamber 401 are in contact, so by using a contact-type shielding structure, the shielding configuration of the divided section 405A can be simplified. In the part where the divided section 405A and the heating chamber 401 are not in contact, a non-contact-type shielding configuration can be used to ensure stable shielding performance. This simplifies the structure of the divided sections 405A and 405B.

[0130] [1.5 Embodiment 5] [1.5.1 Configuration] Figure 34 is a schematic front view of an example configuration of a microwave heating apparatus 500 according to Embodiment 5. The microwave heating apparatus 500 shown in Figure 34 comprises a heating chamber 501, a microwave generating unit 503, and a microwave radiating unit 504.

[0131] The microwave heating device 500 has a dividing section (not shown) for dividing the heating chamber 501, but the dividing section is detachable, and Figure 34 shows the state with the dividing section removed.

[0132] The microwave radiating unit 504 is provided on the top side of the heating chamber 501, and the object to be heated 502 is placed in the heating chamber 501. In this configuration, with the divided section removed, the microwave radiating unit 504 radiates microwaves from the top surface of the heating chamber 501 toward the heating chamber 501, thereby heating the object to be heated 502 with microwaves.

[0133] [1.5.2 Effects] In the microwave heating apparatus 500 of the above-described embodiment 5, microwaves are emitted into the heating chamber 501 from the microwave radiating unit 504 with the divided section removed from the heating chamber 501. With this configuration, any object to be heated 502 that fits into the heating chamber 501 can be heated. This relaxes the dimensional limitations on the object to be heated 502.

[0134] Furthermore, the microwave radiation unit 504 radiates microwaves into the heating chamber 501 from the top surface of the heating chamber 501. With this configuration, by radiating microwaves from the top surface of the heating chamber 501, a longer distance can be secured between the object to be heated 502 and the microwave radiation unit 504 (power supply unit) compared to a configuration in which power is supplied from the bottom surface of the heating chamber 501. This makes it possible to diffuse the microwaves from the microwave radiation unit 504 into the heating chamber 501 and apply them to the object to be heated 502. This configuration is particularly effective for objects to be heated 502 that are short or for objects to be heated 502 where uniformity of heating distribution in the horizontal direction is important. This enables uniform heating.

[0135] [1.6 Embodiment 6] [1.6.1 Configuration] Figure 35 is a schematic side view of an example configuration of a microwave heating device 600 according to Embodiment 6. The microwave heating device 600 shown in Figure 35 comprises a heating chamber 601, a microwave generating unit 603, a microwave radiating unit 604, a dividing unit 605, a hot air heating means 615, a radiant heating means 616, a steam heating means 617, and a dividing unit moving mechanism 627.

[0136] The heating chamber 601 shown in Figure 35 is divided in the height direction Z by a dividing section 605, forming two divided chambers 628A and 628B. The dividing section 605 is made of a material such as metal that shields microwaves and has an electromagnetic wave shielding structure 610. In Figure 35, the object to be heated 602 is placed on the upper surface of the dividing section 605.

[0137] The division section moving mechanism 627 is a mechanism for moving the division section 605 in the vertical direction. The division section moving mechanism 627 moves the division section 605, for example, before or during heating. The division section moving mechanism 627 comprises a mounting section 630 and a sliding section 632. The mounting section 630 is a member for mounting the division section 605 and has, for example, a plate-like shape extending in the horizontal direction. The sliding section 632 is a member that supports the mounting section 630 so that it can move in the vertical direction and extends along the height direction Z. Although not shown in the figures, a gap (slit) is formed in the side wall of the heating chamber 601 to allow the mounting section 630 to pass through.

[0138] The microwave radiation unit 604 is provided on the side of the heating chamber 601. The hot air heating means 615 is a component for heating with hot air and, like the microwave radiation unit 604, is provided on the side of the heating chamber 601. The radiant heating means 616 is a component for heating by radiation and is provided on the top of the heating chamber 601. The steam heating means 617 is a component for heating with steam and, like the microwave radiation unit 604 and the steam heating means 617, is provided on the side of the heating chamber 601.

[0139] [1.6.2 Effects] According to the microwave heating apparatus 600 of the above-described embodiment 6, the dividing section 605 is configured to be movable before or during heating. With this configuration, by moving the dividing section 605 before heating, it is possible to set the dimensions of the dividing chamber 628B to the same size as the object to be heated 602. Furthermore, by moving the dividing section 605 during heating, the dimensions of the dividing chamber 628B can be changed, making it possible to change the heating conditions such as the distribution of microwaves, hot air, and steam. This allows for flexible changes in heating conditions to match the heating state of the object to be heated 602. Note that if the dividing section 605 is made of metal, the standing wave distribution of microwaves changes significantly when the dimensions of the dividing chamber 628B change. This makes it possible to equalize the heating distribution by microwave heating.

[0140] [1.7 Embodiment 7] [1.7.1 Configuration] Figure 36 is a schematic front view of an example configuration of a microwave heating apparatus 700 according to Embodiment 7. The microwave heating apparatus 700 shown in Figure 36 comprises a heating chamber 701, divided sections 705A and 705B, and a microwave radiating section 709.

[0141] The heating chamber 701 shown in Figure 36 is divided in the width direction Y and the height direction Z by dividing sections 705A and 705B, forming four divided chambers 728A, 728B, 728C, and 728D. Dividing section 705A extends in the height direction Z so as to divide the heating chamber 701 in the width direction Y. Dividing section 705B extends in the width direction Y so as to divide the heating chamber 701 in the height direction Z. Dividing section 705A is positioned, for example, at an intermediate position in the width direction Y so as to overlap with the rotation center 721 of the rotating antennas 709A and 709B, which will be described later. Dividing section 705B is positioned, for example, at a height below the rotation center 721 of the rotating antennas 709A and 709B. Dividing sections 705A and 705B may each be, for example, separate or integrated. The divided sections 705A and 705B may, for example, be fixed to the inner wall of the heating chamber 701, or they may be detachable.

[0142] The microwave radiation unit 709 is located on the rear side of the heating chamber 701 and has rotating antennas 709A and 709B. The rotating antennas 709A and 709B are configured to radiate microwaves toward the heating chamber 701, for example, the rotating antenna 709A radiates microwaves in a first direction, and the rotating antenna 709B radiates microwaves in a second direction. The rotating antennas 709A and 709B divide the microwave radiation from the microwave radiation unit 709 into multiple directions. More specifically, multiple radiation points are provided where the distance from the antenna's feed coupling point is an integer multiple of λ / 2, thereby creating multiple radiation directivity points from the antenna.

[0143] The rotating antennas 709A and 709B are integrally rotatable along the rotational direction R4, with the center position 721, which is the center of the heating chamber 701 in the width direction X and height direction Z, as the center of rotation. The angle between the rotating antennas 709A and 709B when the heating chamber 701 is viewed from the front is set to approximately 90 degrees. While the rotating antenna 709A radiates microwaves toward one divided chamber, the rotating antenna 709B radiates microwaves toward the divided chamber adjacent to that chamber. This allows microwaves to be radiated to multiple divided chambers simultaneously.

[0144] [1.7.2 Effects] According to the microwave heating device 700 of the above-described embodiment 7, the microwave radiating unit 709 has the function of simultaneously radiating microwaves in a first direction and a second direction. With this configuration, the antenna feed power can be divided and radiated in multiple directions. This increases the number of heating patterns and allows for the selection of the optimal heating for a wide variety of foods.

[0145] Furthermore, the microwave radiation unit 709 has the function of simultaneously radiating microwaves to multiple divided chambers 728A to 728D using microwaves radiated in the first and second directions. With this configuration, for example, when power is supplied using the rotating antenna 709, it becomes possible to control the power supply to the multiple divided chambers 728A to 728D by controlling the rotation of the rotating antenna 709. This makes it possible to achieve simultaneous finishing of multiple parts, allowing one part to be heated while the other part is heated, and enabling simultaneous heating of multiple parts under similar conditions.

[0146] [1.8 Embodiment 8] [1.8.1 Configuration] Figure 37 is a schematic top view of an example configuration of a microwave heating apparatus 800 according to Embodiment 8. The microwave heating apparatus 800 shown in Figure 37 comprises a heating chamber 801, a dividing section 805, and a door 825.

[0147] The divided section 805 shown in Figure 37 has a radio wave shielding structure 810 on only one of its four sides. Of the four sides of the divided section 805, the radio wave shielding structure 810 is provided on the side facing the door glass 826 of the door 825.

[0148] [1.8.2 Effects] In the microwave heating apparatus 800 of Embodiment 8 described above, a radio wave shielding structure 810 is provided on one side of the divided section 805. With this configuration, the radio wave shielding performance of the divided section 805 is improved by providing the radio wave shielding structure 810 on one side of the divided section 805. Since the standing wave distribution in the heating chamber 801 differs on each side of the divided section 805, the amount of leaked radio waves also differs on each side. Therefore, by providing the radio wave shielding structure 810 on the side with a large amount of leaked radio waves, it is possible to further improve the shielding performance.

[0149] [1.8.3 Modification of Embodiment 8] [1.8.3.1 Variation 1] [1.8.3.1.1 Configuration] Figure 38 is a schematic top view of an example configuration of a microwave heating apparatus 800 according to a modified example 1 of Embodiment 8.

[0150] The divided section 805 shown in Figure 38 has radio wave shielding structures 810 on only two of its four sides. Of the four sides of the divided section 805, the radio wave shielding structures 810A and 810B are provided on the two sides facing both ends (side walls) in the width direction X of the heating chamber 801.

[0151] [1.8.3.1.2 Effects] In the microwave heating apparatus 800 of the above-described embodiment 8, radio wave shielding structures 810A and 810B are provided on two sides of the divided section 805. With this configuration, the radio wave shielding performance of the divided section 805 is improved by providing the radio wave shielding structures 810A and 810B on two sides of the divided section 805. Since the standing wave distribution in the heating chamber 801 differs on each side of the divided section 805, the amount of leaked radio waves also differs on each side. Therefore, by providing the radio wave shielding structures 810A and 810B on the two sides with a large amount of leaked radio waves, it is possible to further improve the shielding performance. [1.8.3.2 Variation 2] [1.8.3.2.1 Configuration] Figure 39 is a schematic top view of an example configuration of a microwave heating apparatus 800 according to a modified example 2 of Embodiment 8.

[0152] The divided section 805 shown in Figure 39 has radio wave shielding structures 810 on only three of its four sides. Of the four sides of the divided section 805, one side facing the door glass 826 of the door 825 is provided with a radio wave shielding structure 810A, and the two sides facing both ends (side walls) in the width direction X of the heating chamber 801 are provided with radio wave shielding structures 810B.

[0153] [1.8.3.2.2 Effects] According to the microwave heating apparatus 800 of Embodiment 8 described above, radio wave shielding structures 810A and 810B are provided on three sides of the divided section 805. With this configuration, the radio wave shielding performance of the divided section 805 is improved by providing the radio wave shielding structures 810A and 810B on three sides of the divided section 805. Since the standing wave distribution in the heating chamber 801 differs on each side of the divided section 805, the amount of leaked radio waves also differs on each side. Therefore, by providing the radio wave shielding structures 810A and 810B on the three sides with a large amount of leaked radio waves, it is possible to further improve the shielding performance.

[0154] [1.9 Embodiment 9] [1.9.1 Configuration] Figures 40 and 41 are schematic top and front views, respectively, of an example configuration of a microwave heating apparatus 900 according to Embodiment 9. The microwave heating apparatus 900 shown in Figure 40 comprises a heating chamber 901, a dividing section 905, and a door 925.

[0155] The divided section 905 shown in Figure 40 has radio wave shielding structures 910 on only three of its four sides. Specifically, of the four sides of the divided section 905, a radio wave shielding structure 910A is provided on one side facing the door glass 926 of the door 925, and radio wave shielding structures 910B are provided on the two sides facing both ends (side walls) in the width direction X of the heating chamber 901. The radio wave shielding structures 910A and 910B are, for example, non-contact choke structures. While the radio wave shielding structure 910B is provided along the entire length of the side of the divided section 905, the radio wave shielding structure 910A is provided only at the ends of the side of the divided section 905 and not in the center of the side. That is, on the side of the divided section 905 facing the door 925, the non-contact radio wave shielding structure 910A is provided in a limited area. As shown in Figure 41, when the heating chamber 901 is viewed from the front, the central part 906 of the divided section 905 is open, making it easier to remove the object to be heated 902 placed on top of the divided section 905.

[0156] [1.9.2 Effects] According to the microwave heating device 900 of Embodiment 9 described above, the radio wave shielding structure 910A is non-contact and is provided in a limited area on the side of the divided section 905 that faces the door 925. With this configuration, the thickness of the divided section when a non-contact radio wave shielding structure is adopted is thicker than that of a flat divided section without a radio wave shielding structure or when a contact-type radio wave shielding structure is adopted. Therefore, by eliminating a portion of the radio wave shielding structure on the door 925 side, which is the side from which food is removed, the thickness of the divided section 905 is partially reduced, the opening is widened, and it becomes easier to remove food.

[0157] [1.10 Embodiment 10] [1.10.1 Configuration] Figure 42 is a schematic front view of an example configuration of a microwave heating device 1000 according to Embodiment 10. As shown in Figure 42, the microwave heating device 1000 comprises a microwave signal generation unit 1002, two signal amplification units 1003A and 1003B, two microwave radiation units 1004A and 1004B, and a phase difference control unit 1006.

[0158] The microwave signal generator 1002 is, for example, a microwave generator using a semiconductor oscillator. The signal amplification units 1003A and 1003B are signal amplifiers that amplify the microwave signal from the microwave signal generator 1002, and are connected to the microwave radiation units 1004A and 1004B, respectively. The phase difference control unit 1006 controls the phase difference of the microwaves irradiated by the multiple microwave radiation units 1004A and 1004B. The phase difference control unit 1006 is connected between the microwave signal generator 1002 and the two signal amplification units 1003A and 1003B. The phase difference control unit 1006 distributes the microwave signal from the microwave signal generator 1002 to each of the two signal amplification units 1003A and 1003B. The phase difference control unit 1006 controls the phase difference between multiple radio waves irradiated by multiple microwave radiators 1004 by controlling the phase difference between radio wave signals distributed to two signal amplification units 1003. The phase difference control unit 1006 can be used to change the microwave distribution within the heating chamber 1001 by changing the phase difference of the radio waves irradiated by the microwave radiators 1004. The phase difference control unit 1006 can be described as a phase variable unit.

[0159] The phase difference control unit 1006 is configured, for example, using a variable capacitance element whose capacitance changes according to the applied voltage. The phase variation range of the phase difference control unit 1006 may be, for example, in the range of 0° to approximately 180°. This allows the phase difference of the power irradiated from the multiple microwave radiation units 1004 to be controlled within the range of 0° to ±180°.

[0160] The microwave heating device 1000 has two radio wave irradiation units 1004 arranged facing each other so that they irradiate each other with radio waves. As shown in Figure 42, the two microwave radiation units 1004 are located on the right and left walls of the heating chamber 1001 and irradiate each other with radio waves.

[0161] The heating chamber 1001 is provided with a dividing section 1005. The heating chamber 1001 is divided in the height direction Z by the dividing section 1005, forming two divided chambers 1028A and 1028B. In the example shown in Figure 42, two microwave radiation units 1004 are installed in the lower divided chamber 1028A, and the object to be heated 1015 is placed in the center of the divided chamber 1028A.

[0162] As shown in Figure 42, by controlling the phase difference of microwaves radiated into the divided chamber 1028A from microwave radiators 1004 located opposite each other within the divided chamber 1028A, it is possible to control the superposition of electric fields of direct waves before the radio waves are reflected by the inner wall of the divided chamber 1028A and the direction and phase of the radio wave radiation are disrupted. For example, if the phase difference of microwaves from the microwave radiators 1004 is 180°, it becomes possible to strongly heat the center of the divided chamber 1028A. If the phase difference of radio waves from the microwave radiators 1004 is 0°, it becomes possible to heat the area around the center of the divided chamber 1028A more than the center. If the phase difference of radio waves from the microwave radiators 1004 is 90°, it is possible to create a radio wave distribution inside the divided chamber 1028A that is biased towards one of the microwave radiators 1004. In this way, by controlling the phase difference of microwaves from multiple microwave emitting units 1004 and controlling the radio wave distribution within the divided chamber 1028A, uniform heating and selective heating of the object to be heated 1015 become possible.

[0163] In the heating device 1000 shown in Figure 42, in order to superimpose the radio waves from the two microwave radiators 1004, it is preferable that the distance between the two microwave radiators 1004 is one wavelength or more in the frequency of the microwaves from the two microwave radiators 1004. In other words, the distance between the irradiation positions of the microwaves to be superimposed is set to one wavelength or more in the frequency of the microwaves.

[0164] [1.10.2 Effects] According to the microwave heating device 1000 of the above-described embodiment 10, the microwave signal generating means 1002 (microwave generating unit) has a semiconductor oscillator. With this configuration, conventional vacuum tube type microwave generating units, such as magnetrons, require an applied voltage of several kV, thus requiring voltage boosting by an inverter. With a semiconductor oscillator, it is possible to generate microwaves with an applied voltage of several tens of volts. Therefore, high-voltage components are unnecessary. This makes it possible to improve safety, simplify the power supply configuration, and reduce costs (reduction in the number of components, elimination of high-voltage components).

[0165] Furthermore, the microwave radiating units 1004A and 1004B each have a microwave radiating unit 1004A (first microwave radiating unit) and a microwave radiating unit 1004B (second microwave radiating unit) that is different from microwave radiating unit 1004A. With this configuration, conventionally, there is only one power supply unit, and the heating distribution of the heated object is controlled by changing the directivity of the microwaves using a rotating antenna or the like. However, in the case of a heating chamber the size of a microwave oven, the heating distribution of the heated object is greatly affected by the standing wave distribution caused by microwaves reflected from the walls of the heating chamber. In the case of a rotating antenna, this standing wave distribution can only be controlled by the direction of the antenna. By arranging semiconductor oscillators in each of the multiple power supply units, it becomes possible to control the frequency and phase difference, and the standing wave distribution can be controlled in a more diverse way. This makes it possible to achieve uniform heating and selective heating. Furthermore, in a configuration where the microwave output of each power supply unit can be controlled independently, the object to be heated 1015 can be selectively heated by radiating microwaves from a semiconductor microwave oscillator close to the object to be heated 1015.

[0166] Furthermore, the system includes a phase control unit 1006 (phase difference control means) that controls the phase of microwaves emitted by the microwave radiating unit 1004A and the microwave radiating unit 1004B, respectively. With this configuration, by changing the phase difference between the multiple microwave radiating units 1004A and 1004B, the direction of superposition of electric fields at each location within the heating chamber 1001 changes, and thus the overall radio wave distribution within the heating chamber 1001 also changes. When the object to be heated 1015 is placed in the divided chamber 1028A, the distribution of the amount of radio waves absorbed by the object to be heated 1015 and the absorbed power also differ due to the phase difference. Therefore, by changing the phase difference, it is possible to stir the electric field distribution within the divided chamber 1028A. By changing the phase difference and stirring the electric field distribution within the divided chamber 1028A, it becomes possible to heat the object to be heated 1015 with different combinations of absorbed power distributions, thereby achieving uniform heating of the object to be heated 1015.

[0167] Furthermore, microwave radiators 1004A and 1004B each radiate microwaves into the heating chamber 1001 from positions opposite to each other. With this configuration, by controlling the phase of the microwaves radiated into the heating chamber 1001 from opposing positions, it is possible to control the superposition of the electric fields of direct waves before the microwaves are reflected by the inner wall of the heating chamber 1001 and the radiation direction and phase are disrupted. As a result, for example, when the phase difference is pi, it is possible to strongly heat the center of the heating chamber 1001, and when the phase difference is zero, heating is possible around the center. Also, when the phase difference is pi / 2, a biased microwave distribution is obtained. In this way, by controlling the phase of the microwaves radiated by microwave radiators 1004A and 1004B and controlling the microwave distribution within the heating chamber 1001, uniform heating and selective heating of the object to be heated 1015 become possible. Note that the radiation positions of the microwaves whose phases are controlled should be designed to have a distance of one wavelength or more at the radiated frequency. [1.10.3 Examples relating to Embodiment 10]

[0168] The ability to uniformly heat the object to be heated 1015 by using multiple combinations of frequency and phase difference will be further explained with reference to Figures 43 to 47. In Figures 43 to 47, the object to be heated 1015 is, for example, frozen lasagna, which is rectangular in shape in plan view. In other words, Figures 43 to 47 show the temperature distribution when frozen lasagna is thawed. Below, an example of microwave heating of the object to be heated 1015 placed in the heating chamber 1001 with the divided section 1005 removed will be described. It is also considered that a similar trend will occur when microwave heating of the object to be heated 1015 placed in the divided chamber 1028A with the divided section 1015 installed in the heating chamber 1001, as shown in Figure 42.

[0169] Figure 43 illustrates the heating distribution of the object 1015 when the phase difference is 0°. As shown in Figure 43, when the phase difference between the microwaves irradiated from the two microwave radiators 1004A and 1004B is 0°, the region R12 surrounding the central region R11 of the object 1015 is hotter than the central region R11. Figure 44 illustrates the heating distribution of the object 1015 when the phase difference is 180°. As shown in Figure 44, when the phase difference between the microwaves irradiated from the two microwave radiators 1004A and 1004B is 180°, the central region of the object 1015 and the surface region R13 of the object 1015 are hotter than the region R14 surrounding the center. Therefore, it is thought that the object to be heated 1015 can be uniformly heated by combining heating with a phase difference of 0° between microwaves irradiated from two microwave radiators 1004A and 1004B and heating with a phase difference of 180° between microwaves irradiated from two microwave radiators 1004A and 1004B. Figure 45 is a diagram illustrating the heating distribution of the object to be heated 1015 when a phase difference of 0° and a phase difference of 180° are combined. As is clear from Figure 45, it was confirmed that the object to be heated 1015 can be uniformly heated by combining heating with a phase difference of 0° between microwaves irradiated from two microwave radiators 1004A and 1004B and heating with a phase difference of 180° between microwaves irradiated from two microwave radiators 1004A and 1004B.

[0170] Figure 46 illustrates the heating distribution of the object 1015 in the comparative example. The comparative example is a conventional microwave oven, in which the object 1015 is heated by rotating it on a turntable. In this case, as is clear from Figure 46, the temperature of the four corner regions R15 of the object 1015 is higher than that of the center, indicating that the object 1015 is heated from the corners. Figure 47 illustrates the heating distribution of the object 1015 after heat treatment in the comparative example. As is clear from Figure 47, the temperature of the four corner regions R16 of the object 1015 is clearly higher than that of the center. Therefore, the corners are overheated before the center of the object 1015 is sufficiently warmed. If the object 1015 is frozen lasagna, the dough at the corners of the frozen lasagna will become dehydrated or burned before the center of the frozen lasagna is sufficiently thawed.

[0171] Next, the simulation of the radio wave distribution in the heating chamber and the heating distribution of the object being heated, based on frequency and phase difference, will be explained with reference to Figures 48 and 49. Figure 48 is a diagram illustrating the model used for the simulation of the radio wave distribution in the heating chamber and the heating distribution of the object being heated, based on frequency and phase difference. The model shown in Figure 48 has four feed points P1 to P4. For example, feed points P1 and P2 correspond to the microwave radiation unit 1004A, and feed points P3 and P4 correspond to the microwave radiation unit 1004B. In the model shown in Figure 48, the four feed points P1 to P4 are located at the four corners of the bottom wall surface 1008 of the heating chamber 1001. More specifically, feed points P1 and P2 are located on the first end side in the longitudinal direction of the bottom wall surface 1008 (right side in Figure 48), and feed points P3 and P4 are located on the second end side in the longitudinal direction of the bottom wall surface 1008 (left side in Figure 48).

[0172] Figure 49 illustrates the differences in the radio wave distribution in the heating chamber and the heating distribution of the object being heated, based on frequency and phase difference, in the model shown in Figure 48. The frequencies of the radio waves radiated from the four feed points P1 to P4 are equal, being either 2413 MHz, 2455 MHz, or 2495 MHz. The phase difference is the phase difference between the radio waves radiated from feed points P1 and P2 and the radio waves radiated from feed points P3 and P4, which changes the phase of the radio waves radiated from feed points P3 and P4.

[0173] As is clear from Figure 49, the radio wave distribution within the heating chamber 1001 changes significantly depending on the combination of frequency and phase difference. Similarly, the heating distribution of the object being heated 1015 changes significantly depending on the combination of frequency and phase difference. Thus, the radio wave distribution within the heating chamber 1001 and the heating distribution of the object being heated 1015 are uniquely determined by the combination of frequencies and phase differences of multiple radio waves. Therefore, it is possible to control the radio wave distribution within the heating chamber 1001 and the heating distribution of the object being heated 1015 by the combination of frequency and phase difference.

[0174] At least one of the height, width, and depth dimensions of the heating chamber 1001 may be less than or equal to half the wavelength of the radio waves emitted from the microwave radiators 1004A and 1004B. In the direction of the heating chamber 1001 where the dimensions are less than or equal to half the wavelength of the radio waves emitted from the microwave radiators 1004A and 1004B, a radio wave distribution (electric field distribution) is less likely to occur, making it easier to control the radio wave distribution within the heating chamber 1001 by adjusting the frequency and phase difference. In particular, at least one of the height, width, and depth dimensions of the heating chamber 1001 may be less than or equal to one-quarter of the wavelength of the radio waves emitted from the microwave radiators 1004A and 1004B. In the direction of the heating chamber 1001 where the dimensions are less than or equal to one-quarter of the wavelength of the radio waves emitted from the microwave radiators 1004A and 1004B, no radio wave distribution (electric field distribution) occurs, making it even easier to control the radio wave distribution within the heating chamber 1001 by adjusting the frequency and phase difference. Thus, the shape of the heating chamber 1001 can determine whether or not a radio wave distribution is generated. Therefore, the controllability of the radio wave distribution within the heating chamber 1001 can be improved. This makes it easier to selectively perform uniform heating and selective heating of the object to be heated 1015. When the object to be heated 1015 is inside the heating chamber 1001, the presence of the object to be heated 1015 affects the radio wave distribution within the heating chamber 1001. However, if the size of the object to be heated 1015 is a practical size that can be accommodated in the heating chamber 1001, it is possible to control the radio wave distribution within the heating chamber 1001 by frequency and phase difference.

[0175] If the divided section 1005 is installed in the heating chamber 1001, the dimensions of the divided chamber 1028A where the object to be heated 1015 is placed should be designed as described above.

[0176] [1.11 Embodiment 11] [1.11.1 Configuration] Figure 50 is a schematic front view of an example configuration of a microwave heating device 1100 according to Embodiment 11. As shown in Figure 50, the heating device 1100 has a dividing section 1105 that divides the heating chamber 1101. The heating chamber 1101 is divided in the height direction Z by the dividing section 1105, forming two divided chambers 1128A and 1128B. The object to be heated 1115A is placed in the lower divided chamber 1128A, and the object to be heated 111BA is placed in the upper divided chamber 1128B.

[0177] The microwave heating device 1100 has four microwave supply units 1103A to 1103D. Microwave supply units 1103A and 1103B are located on the bottom side of the heating chamber 1101 to supply microwaves toward the lower divided chamber 1128A, while microwave supply units 1103C and 1103D are located on the top side of the heating chamber 1101 to supply microwaves toward the upper divided chamber 1128B.

[0178] Each of the microwave supply units 1103A to 1103D comprises a plurality of microwave radiation units 1104A to 1104D, a plurality of microwave signal generation units 1130A to 1130D, a plurality of signal amplification units 1131A to 1131D, and a plurality of microwave control units 1132A to 1132D.

[0179] Each of the microwave control units 1132A to 1132D serves as both a "frequency control unit" and a "power control unit." Each of the microwave control units 1132 to 1132D has both the function of controlling the microwave frequency and the function of controlling the microwave power.

[0180] Each of the microwave control units 1132A to 1132D, acting as frequency control units, controls the frequency of the radio waves emitted by the microwave radiating units 1104A to 1104D. For example, each of the microwave control units 1132A to 1132D controls the frequency of the radio waves emitted by the microwave radiating units 1104A to 1104D within a predetermined frequency range. The predetermined frequency range may be appropriately selected from the frequency range usable for dielectric heating of the objects to be heated 1115A and 1115B. Each of the microwave control units 1132A to 1132D controls the frequency of the radio waves emitted by the microwave radiating units 1104A to 1104D by controlling the frequency of the radio wave signals generated by the radio wave signal generating units 11320 to 1130D. The microwave control units 1132A to 1132D can be used to change the frequency of the microwaves irradiated by the microwave radiating units 1104A to 1104D, depending on the objects to be heated 1115A and 1115B. Each of the microwave control units 1132A to 1132D, acting as frequency control units, can be considered a frequency variable unit.

[0181] The microwave control units 1132A to 1132D, acting as power control units, each control the output of the radio waves emitted by the microwave radiating units 1104A to 1104D. The microwave control units 1132A to 1132D each control the output of the radio waves emitted by the microwave radiating units 1104A to 1104D by controlling the magnitude of the microwave signal generated by the microwave signal generating units 1130A to 1130D. The microwave control units 1132A to 1132D can each be used to change the output of the microwaves emitted by the microwave radiating units 1104A to 1104D according to the objects being heated 1115A and 1115B. In essence, the microwave control units 1132A to 1132D, acting as power control units, can each be described as variable output units. Furthermore, each of the microwave control units 1132A to 1132D may control the output of the radio waves irradiated by the microwave radiating units 1104A to 1104D by other means such as changing the amplification ratio of the signal amplification units 1131A to 1131D or changing the voltage of the internal power supply connected to the signal amplification units 1131A to 1131D.

[0182] The microwave control units 1132A to 1132D, which serve as the frequency control unit and power control unit, may be configured, for example, by a microcontroller having one or more processors and memory. The microwave control units 1132A to 1132D may also be configured, for example, by an FPGA (Field-Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit).

[0183] [1.11.2 Effects] The microwave heating apparatus 1100 of the above-described embodiment 11 further includes microwave control units 1132A to 1132D as frequency control means for varying the frequency of microwaves generated by microwave signal generation units 1130A to 1130D (microwave generation units). With this configuration, radio waves of the optimal frequency are irradiated according to the heating objects 1115A and 1115B which have different dielectric constants. Furthermore, it becomes possible to change the microwave distribution within the heating chamber 1101. This enables efficient heating of dielectrics and uniform heating. Note that the optimal frequency for heating differs not only depending on the dielectric constant of the dielectric, but also on its size, weight, container, and placement. Even when there are such differences in dielectrics, the present invention enables efficient heating. In addition, even for the same dielectric, the half-depth differs depending on the frequency, so heating at the optimal frequency is effective depending on whether the purpose is to mainly heat the surface or to heat the interior as well.

[0184] Furthermore, the system includes microwave control units 1132A to 1132D, which serve as power variable means for varying the power of the microwaves generated by the microwave signal generation units 1130A to 1130D (microwave generation units). With this configuration, precise output control in increments of a few watts enables microwave heating at an output suitable for the objects to be heated 1115A and 1115B. For objects to be heated 1115A and 1115B, such as frozen products, which require precise control of microwave output, optimal microwave output heating becomes possible, enabling heating to the desired temperature, which was not possible with conventional output control in increments of several hundred watts. In addition, it becomes possible to stably and continuously oscillate low microwaves of a few watts to continue heating the objects to be heated 1115A and 1115B. For objects 1115A and 1115B that cannot be heated with high-power microwaves, such as eggs, low-power microwave heating allows for heating while preventing overheating by conducting heat within the objects 1115A and 1115B, enabling low-temperature heating that was not possible with conventional high-power heating. This makes it possible to heat at the appropriate temperature (improved heating performance) and to heat objects 1115A and 1115B (such as eggs) that could not be heated before.

[0185] [1.11.3 Examples relating to Embodiment 11] Figure 51 illustrates the difference in heating distribution of the object to be heated 1115A due to the frequency of radio waves emitted from the two microwave radiators 1104A and 1104B and the phase difference between the radio waves emitted from the two microwave radiators 1104A and 1104B. Below, an example of microwave heating of the object to be heated 1115A placed in the heating chamber 1101 with the dividing section 1105 removed will be described. It is also considered that a similar trend will occur when microwave heating of the object to be heated 1115A placed in the dividing chamber 1128A with the dividing section 1105 installed in the heating chamber 1101, and when microwave heating of the object to be heated 1115B placed in the dividing chamber 1128B, as shown in Figure 50.

[0186] Figure 51 shows the heating distribution of the object to be heated 1115A for combinations of the frequency of radio waves emitted from the two microwave radiators 1104A and 1104B and the phase difference between the radio waves emitted from the two microwave radiators 1104A and 1104B. In Figure 51, the frequencies are 902MHz, 906MHz, 910MHz, 914MHz, 918MHz, 922MHz, and 926MHz, and the phase differences are 0°, 30°, 60°, 90°, 120°, 150°, and 180°. The object to be heated 1115A is, for example, roast beef.

[0187] As is clear from Figure 51, the heating distribution of the heated object 1115A changes significantly depending on the combination of frequency and phase difference. When the frequency is 914MHz, 918MHz, 922MHz, and 926MHz, and the phase difference is 0°, 30°, and 60°, the temperature is higher in the central part and on both sides in the length direction of the heated object 1115A. On the other hand, when the frequency is 906MHz and the phase difference is 120°, 150°, and 180°, the temperature is higher on both sides in the width direction of the heated object 1115A. Thus, even with the same heated object 1115A, the heating area can be selected by the combination of frequency and phase difference, and by using multiple combinations of frequency and phase difference, uniform heating becomes possible.

[0188] Figures 52 to 55 illustrate the differences in heating distribution due to frequency and phase difference for different types of heated objects 1115A. Figures 52 and 54 show the heating distribution of heated objects 1111, 1112, and 1113 (see Figures 53 and 55) for combinations of the frequency of radio waves emitted from two microwave radiators 1104A and 1104B and the phase difference of the radio waves emitted from the two microwave radiators 1104A and 1104B. Heated objects 1111 and 1112 are, for example, vegetables. Heated object 1111 is, for example, a potato. Heated object 1112 is, for example, a bell pepper. Heated object 1113 is, for example, meat. Heated object 1113 is, for example, beef.

[0189] In Figure 52, the frequencies are 2400MHz, 2420MHz, 2440MHz, 2460MHz, 2480MHz, and 2500MHz, and the phase differences are 0°, 30°, 60°, 90°, 120°, 150°, and 180°. Figure 53 shows the heating distribution of the heated objects 1111, 1112, and 1113 when the phase difference is 0° and the frequency is 2400MHz, as shown in Figure 52. In Figure 54, the frequencies are 902MHz, 906MHz, 910MHz, 914MHz, 918MHz, 922MHz, and 926MHz, and the phase differences are 0°, 30°, 60°, 90°, 120°, 150°, and 180°. Figure 55 shows the heating distribution of the heated objects 1111, 1112, and 1113 when the phase difference is 0° and the frequency is 914 MHz, as shown in Figure 54.

[0190] As is clear from Figures 52 to 55, the heating distribution changes significantly depending on the type of object being heated (1111 to 1113) due to the combination of frequency and phase difference. As shown in Figure 52, when the frequency is 2400MHz to 2500MHz (2450±50MHz), it is possible to heat objects 1111 and 1112 more than object 1113. Since objects 1111 and 1112 are vegetables and object 1113 is meat, the frequency of 2400MHz to 2500MHz is effective for selectively heating vegetables (objects 1111 and 1112), as shown in Figure 53. As shown in Figure 54, when the frequency is 902MHz to 928MHz (915±13MHz), it is possible to heat object 1113 more than object 1111 and 1112. Since the heated objects 1111 and 1112 are vegetables and the heated object 1113 is meat, the frequency range of 902MHz to 928MHz is effective for selectively heating the meat (heated object 1113), as shown in Figure 55. In this way, by combining frequency and phase difference, it is possible to selectively heat different types of heated objects 1111, 1112, and 1113, and by using multiple combinations of frequency and phase difference, it is possible to heat different types of heated objects 1111, 1112, and 1113 uniformly.

[0191] [1.12 Embodiment 12] [1.12.1 Configuration] Figure 56 is a schematic front view of an example configuration of a microwave heating device 1200 according to Embodiment 12. As shown in Figure 56, the microwave heating device 1200 comprises a heating chamber 1201 and a dividing section 1205 that divides the heating chamber 1201 in the height direction Z. The object to be heated 1115A is placed in the lower dividing chamber 1228A, and the object to be heated 1115B is placed in the upper dividing chamber 1228B.

[0192] In this embodiment, the divided portion 1205 is not provided with a radio wave shielding structure such as a choke structure, and a non-contact type radio wave shielding structure 1210 is provided on the inner wall 1220 of the heating chamber 1201. The divided portion 1205 is supported by contact with the inner wall 1220 of the heating chamber 1201 at locations other than those facing the radio wave shielding structure 1210.

[0193] [1.12.2 Effects] According to the microwave heating apparatus 1200 of Embodiment 12 described above, a radio wave shielding structure 1210 is provided on the inner wall 1220 of the heating chamber 1201. With this configuration, the non-contact type radio wave shielding structure 1210 can also be provided on the inner wall 1220 of the heating chamber 1201. Alternatively, a part of the radio wave shielding structure can be provided on the inner wall 1220 of the heating chamber 1201, and the remaining radio wave shielding structure can be provided on the divided section 1205. By eliminating or simplifying the radio wave shielding structure of the divided section 1205, it is possible to prevent deformation of the radio wave shielding structure and the resulting decrease in radio wave shielding performance caused by the heated objects 1115A and 1115B coming into contact with the divided section 1205 when the heated objects 1115A and 1115B are removed. It is also expected that deformation of the radio wave shielding structure when the divided section 1205 is removed can be prevented. This makes it possible to simplify the structure of the divided section 1205 and stabilize the shielding performance.

[0194] [1.13 Embodiment 13] [1.13.1 Configuration] Figure 57 is a schematic side view of an example configuration of a microwave heating device 1300 according to Embodiment 13. As shown in Figure 57, the microwave heating device 1300 comprises a heating chamber 1301, a microwave generating unit 1303, a microwave radiating unit 1304, and a dividing unit 1305.

[0195] The heating chamber 1301 shown in Figure 57 is divided in the height direction Z by a dividing section 1305, forming two divided chambers 1328A and 1328B. The dividing section 1305 is made of a material such as metal that shields microwaves, and has a non-contact or contact type radio wave shielding structure 1310. In Figure 57, the object to be heated 1302A is placed in the lower divided chamber 1328A, and the object to be heated 1302B is placed in the upper divided section 1328B.

[0196] The microwave generator 1303 and microwave radiator 1304 are located on the rear side X2 of the heating chamber 1301. The microwave radiator 1304 radiates microwaves from the rear side of the heating chamber 1301 toward the heating chamber 1301. The microwave radiator 1304 further has a rotating antenna 1309. The rotating antenna 1309 radiates microwaves toward the divided chamber 1328A and the divided chamber 1328B, respectively, depending on its rotational position.

[0197] As shown in Figure 57, the divided portion 1305 has a mounting surface 1320 for placing the object to be heated 1302B. The mounting surface 1320 is made of, for example, a dielectric material. The divided portion 1305 has a recess 1322 below the mounting surface 1320, and the dielectric material 1324 is placed in the recess 1322. [1.13.2 Effects] According to the microwave heating device 1300 of the above-described embodiment 13, the mounting surface 1320 is made of a dielectric, and the divided portion 1305 has a recess 1322 below the mounting surface 1320, and a dielectric 1324 is provided in the recess 1322. With this configuration, wavelength compression of microwaves occurs within the dielectric 1324 according to the dielectric constant of the dielectric 1324. By placing the dielectric 1324 in the recess 1322, the wavelength compression within the dielectric 1324 results in a microwave distribution around the dielectric 1324 that is different from the distribution when the dielectric 1324 is not present. Therefore, it is possible to homogenize the heating distribution of the object to be heated 1302B according to the dielectric constant, shape, and placement of the dielectric 1324. This enables uniform heating.

[0198] Although the invention of this disclosure has been described above with reference to the embodiments described above, the invention of this disclosure is not limited to the embodiments described above. Although this disclosure is sufficiently described in relation to preferred embodiments with reference to the accompanying drawings, various variations and modifications will be obvious to those skilled in this art. Such variations and modifications should be understood to be included within the scope of the invention as defined in the attached claims. Furthermore, changes in the combination and order of elements in each embodiment can be realized without departing from the scope and spirit of this disclosure.

[0199] Furthermore, by appropriately combining any of the above embodiments, the effects of each embodiment can be achieved. [Industrial applicability]

[0200] This disclosure is applicable to any microwave heating device that heats and cooks food or other items using microwaves. [Explanation of Symbols]

[0201] 1 Heating chamber 2A, 2B Heated object 3. Microwave Generator 4. Microwave radiation section 5 Division 6A, 6B sensors 100 Microwave heating device 101 Control Unit 102 Bottom 104 Top surface X depth direction Y width direction Z (height direction)

Claims

1. A heating chamber in which the object to be heated is placed, A microwave generating unit that generates microwaves, A microwave radiating unit that radiates microwaves generated by the microwave generating unit into the heating chamber, The heating chamber includes a dividing section that divides the space of the heating chamber into at least two divided chambers, Microwave heating device.

2. The microwave heating apparatus according to claim 1, further comprising at least one of a hot air heating means, a radiant heating means, and a steam heating means.

3. The microwave heating apparatus according to claim 1 or 2, wherein two of the aforementioned divided chambers are provided.

4. The microwave heating apparatus according to claim 1 or 2, wherein three or more of the divided chambers are provided.

5. A microwave heating apparatus according to any one of claims 1 to 4, wherein only one of the divided chambers has the function of heating the object to be heated.

6. A microwave heating apparatus according to any one of claims 1 to 4, wherein two of the divided chambers have the function of heating an object to be heated.

7. The microwave heating apparatus according to any one of claims 1 to 6, wherein the divided portion is detachably attached to the inner wall of the heating chamber.

8. The microwave heating apparatus according to claim 7, wherein microwaves are emitted into the heating chamber from the microwave radiating unit with the divided section removed from the heating chamber.

9. The microwave heating apparatus according to any one of claims 1 to 8, wherein the divided portion is made of a dielectric material.

10. The microwave heating apparatus according to any one of claims 1 to 8, wherein the divided portion is made of metal.

11. A microwave heating apparatus according to any one of claims 1 to 10, wherein an insulator is provided between the divided portion and the inner wall of the heating chamber.

12. The microwave heating apparatus according to any one of claims 1 to 11, wherein the dividing section divides the heating chamber in the height direction.

13. The microwave heating apparatus according to any one of claims 1 to 11, wherein the dividing portion divides the heating chamber in the width direction.

14. The microwave heating apparatus according to any one of claims 1 to 11, wherein the dividing section divides the heating chamber in the depth direction.

15. The microwave heating apparatus according to any one of claims 1 to 14, wherein the divided portion is configured to be movable before or during heating.

16. The microwave heating apparatus according to any one of claims 1 to 15, wherein the divided portion has a mounting surface on which an object to be heated is placed.

17. The microwave heating apparatus according to claim 16, wherein the mounting surface is made of a dielectric, and the divided portion forms a recess below the mounting surface described above.

18. The microwave heating apparatus according to claim 17, wherein a dielectric material is provided in the recess.

19. The microwave heating apparatus according to claim 17 or 18, wherein a metal is provided in the recess.

20. The microwave heating apparatus according to any one of claims 1 to 19, wherein each of the divided chambers is provided with a sensor.

21. The microwave heating apparatus according to any one of claims 1 to 20, wherein an infrared sensor is provided in at least one of the divided chambers.

22. The microwave heating apparatus according to any one of claims 1 to 21, wherein a steam sensor is provided in at least one of the divided chambers.

23. The microwave heating apparatus according to any one of claims 1 to 22, wherein a microwave sensor is provided in at least one of the divided chambers.

24. The microwave heating apparatus according to any one of claims 1 to 23, wherein a camera is provided in at least one of the divided chambers.

25. The aforementioned divided chamber has a first divided chamber and a second divided chamber. A microwave heating apparatus according to any one of claims 1 to 24, wherein a first sensor is provided in the first divided chamber, and a second sensor of a different type from the first sensor is provided in the second divided chamber.

26. The microwave heating apparatus according to any one of claims 1 to 25, wherein the microwave radiation unit radiates microwaves into the heating chamber from the bottom surface of the heating chamber.

27. The microwave heating apparatus according to any one of claims 1 to 25, wherein the microwave radiation unit radiates microwaves into the heating chamber from the top surface of the heating chamber.

28. The microwave heating apparatus according to any one of claims 1 to 25, wherein the microwave radiation unit radiates microwaves into the heating chamber from the side of the heating chamber.

29. The microwave heating apparatus according to any one of claims 1 to 25, wherein the microwave radiation unit radiates microwaves into the heating chamber from the back surface of the heating chamber.

30. The microwave heating apparatus according to any one of claims 1 to 29, wherein the microwave radiating unit comprises a rotating antenna.

31. The microwave heating apparatus according to claim 30, wherein the microwave radiating unit has the function of radiating microwaves while continuously rotating the rotating antenna.

32. The microwave heating apparatus according to claim 30 or 31, wherein the microwave radiating unit has the function of radiating microwaves while stopping the rotating antenna.

33. The microwave heating apparatus according to any one of claims 30 to 32, wherein the rotating antenna is controlled to rotate within a predetermined range of rotation.

34. The microwave heating apparatus according to any one of claims 1 to 33, wherein the microwave radiation unit has the function of simultaneously radiating microwaves in a first direction and a second direction.

35. The microwave heating apparatus according to claim 34, wherein the microwave radiation unit has the function of simultaneously radiating microwaves to a plurality of divided chambers using microwaves radiated in the first direction and the second direction.

36. The microwave heating apparatus according to any one of claims 1 to 35, wherein the divided portion is fixed to the heating chamber.

37. The microwave heating apparatus according to any one of claims 1 to 36, wherein the divided portion is provided with a unidirectional radio wave shielding structure.

38. The microwave heating apparatus according to any one of claims 1 to 37, wherein the divided portion is provided with a radio wave shielding structure in both directions.

39. The microwave heating apparatus according to any one of claims 1 to 38, wherein a radio wave shielding structure is provided on one side of the divided portion.

40. The microwave heating apparatus according to any one of claims 1 to 38, wherein a radio wave shielding structure is provided on two sides of the divided portion.

41. The microwave heating apparatus according to any one of claims 1 to 38, wherein a radio wave shielding structure is provided on three sides of the divided portion.

42. The microwave heating apparatus according to any one of claims 1 to 38, wherein a radio wave shielding structure is provided on all four sides of the divided portion.

43. A microwave heating apparatus according to any one of claims 1 to 42, wherein different radio wave shielding structures are provided in the corner portion and the portion other than the corner portion of the divided portion.

44. A microwave heating apparatus according to any one of claims 1 to 43, wherein a first radio wave shielding structure is provided on the first side of the divided portion, and a second radio wave shielding structure different from the first radio wave shielding structure is provided on the second side of the divided portion.

45. The microwave heating apparatus according to claim 44, wherein the first side is the side on the door side of the divided portion.

46. The microwave heating apparatus according to claim 44, wherein the first side is the side of the divided portion that is closer to the microwave radiating portion.

47. The microwave heating apparatus according to any one of claims 37 to 46, wherein the radio wave shielding structure is non-contact and is provided on an edge of the divided portion other than the door side.

48. The microwave heating apparatus according to any one of claims 37 to 46, wherein the radio wave shielding structure is non-contact and is provided in a limited area of ​​the door-side edge of the divided portion.

49. The microwave heating apparatus according to any one of claims 1 to 48, wherein a radio wave shielding structure is provided on the inner wall of the heating chamber.

50. The microwave heating apparatus according to any one of claims 1 to 49, wherein the radio wave shielding structure comprises a contact-type first radio wave shielding structure and a non-contact-type second radio wave shielding structure.

51. The microwave heating apparatus according to any one of claims 37 to 50, wherein the radio wave shielding structure has a dielectric cover.

52. The microwave heating apparatus according to any one of claims 37 to 51, wherein the radio wave shielding structure is a non-contact type choke.

53. The aforementioned division section divides the heating chamber in the height direction, The microwave heating apparatus according to any one of claims 1 to 52, wherein the inner wall of the heating chamber has an inclined shape for centering the divided portion toward the center of the heating chamber.

54. The microwave heating apparatus according to any one of claims 1 to 53, wherein the microwave generating unit has a semiconductor oscillator.

55. The microwave heating apparatus according to any one of claims 1 to 54, wherein the microwave radiating section comprises a first microwave radiating section and a second microwave radiating section different from the first microwave radiating section.

56. The microwave heating apparatus according to claim 55, further comprising a phase control means for controlling the phase of microwaves emitted by the first microwave radiating unit and the second microwave radiating unit, respectively.

57. The microwave heating apparatus according to claim 55 or 56, wherein the first microwave radiating unit and the second microwave radiating unit each radiate microwaves into the heating chamber from positions facing each other.

58. The microwave heating apparatus according to any one of claims 1 to 57, further comprising a frequency variable means for varying the frequency of microwaves generated by the microwave generating unit.

59. The microwave heating apparatus according to any one of claims 1 to 58, further comprising a power variable means for varying the power of the microwaves generated by the microwave generating unit.

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