Microwave oven

Abstract

The invention provides a microwave oven which can improve heating efficiency of a heated object and restrain uneven heating with a simple structure. A microwave oven (10) is provided with a heating chamber (14), a bottom microwave source (31A) and a rear microwave source (31B) disposed outside the heating chamber (14), a bottom power supply unit (33A) disposed below a bottom wall (15) of the heating chamber (14), a rear power supply unit (33B) disposed behind a rear wall (18) of the heating chamber (14), and a control unit (50) that individually controls the microwave sources (31A, 31B).

Description

Technical Field

[0001] The present invention relates to a microwave oven. Background Art

[0002] Patent Document 1 discloses a microwave oven having power supply units for radiating microwaves disposed on the ceiling, bottom, and a pair of side walls of a heating chamber. To adjust the radiation direction of the microwaves radiated from each power supply unit, the microwave oven further includes a first antenna and a second antenna of different shapes, and a control unit for adjusting their rotational angles.

[0003] The first and second antennas are positioned on opposing walls of the heating chamber. Specifically, the first antenna is positioned on the top wall and one of a pair of side walls, while the second antenna is positioned on the bottom wall and the other of the pair of side walls. The control unit detects reflected microwaves and adjusts the angles of the first and second antennas to minimize reflected power, thereby improving heating efficiency and minimizing uneven heating of the object being heated.

[0004] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Laid-Open No. 2009-181727 Summary of the Invention

[0005] Problems to be solved by the invention The microwave oven disclosed in Patent Document 1 requires antennas to be disposed on the top and bottom walls, and antennas to be disposed on each of the pair of side walls, resulting in a complex structure. In other words, the microwave oven disclosed in Patent Document 1 has room for improvement in terms of improving heating efficiency of the heated object and suppressing uneven heating with a simple structure.

[0006] An object of the present invention is to provide a microwave oven that can improve the heating efficiency of an object to be heated and suppress uneven heating with a simple structure.

[0007] Technical solutions to problems One embodiment of the present invention provides a microwave oven comprising: a heating chamber defined by a bottom wall, a top wall, a pair of side walls, a rear wall, and a door; a bottom microwave source and a rear microwave source, respectively arranged outside the heating chamber; a bottom power supply portion arranged on the lower side of the bottom wall, radiating microwaves emitted by the bottom microwave source into the heating chamber via the bottom wall; a rear power supply portion arranged on the rear side of the rear wall, radiating microwaves emitted by the rear microwave source into the heating chamber via the rear wall; and a control portion for individually controlling the bottom microwave source and the rear microwave source.

[0008] Microwave ovens are often installed in a dedicated space within a kitchen's cutlery rack. The depth of this space is generally determined by the usability of the kitchen where the cutlery rack is installed. The height of this space is generally determined by the storage capacity of cutlery. Furthermore, considering the size of the kitchen, users can select the desired width of the cutlery rack, including the space.

[0009] Typically, the depth and height of a microwave oven are determined by the dimensions of the space needed to accommodate the dish rack. Meanwhile, the lateral width of a microwave oven is determined by the capacity of the heating chamber, increasing as the capacity increases, leading to a more horizontally elongated shape. In other words, while the depth and height of a microwave oven are highly stable, its lateral width is highly variable. Furthermore, the distance from the bottom wall and rear wall to the object being heated within the heating chamber is often closer than the distance from the side walls.

[0010] In this method, microwave-radiating power supply units are located on the bottom and rear walls, respectively. Because the bottom and rear walls are located close to the object being heated, microwaves that diffuse as they move away from the power supply units can be concentrated on the object. This simple structure improves heating efficiency. Furthermore, since the microwaves from the bottom microwave source and the rear microwave source radiate in different directions, the two microwave sources can be independently controlled by a control unit, thereby minimizing uneven heating of the object.

[0011] A tray holding unit is provided between the bottom power supply unit and the rear power supply unit within the heating chamber. The tray holding unit is configured to position a tray holding the object to be heated along the bottom wall. The tray can be selected from at least one of a heating tray capable of generating heat through microwaves, a translucent tray capable of transmitting microwaves, and a reflective tray capable of reflecting microwaves. When using a heating tray, the heating tray is heated by microwaves radiated from the bottom power supply unit. Therefore, the object to be heated is heated from its lower surface by the heat of the heating tray, while the object is heated from the inside by microwaves radiated from the rear power supply unit. This improves heating efficiency while minimizing uneven heating of the object. When using a translucent tray, the object to be heated is heated by microwaves radiated from both the bottom power supply unit and the rear power supply unit. This improves heating efficiency while minimizing uneven heating of the object. When using a reflective tray, the object to be heated is heated by microwaves radiated from the bottom power supply unit while the object to be heated is heated from the reflective tray by microwaves radiated from the rear power supply unit. Therefore, different objects to be heated can be heated simultaneously and individually, so that the heating efficiency of the objects to be heated can be improved and the convenience for the user can be improved.

[0012] At least a part of the rear power supply portion is located at an upper side than the upper end of the tray when the heating chamber is viewed from the door side. Thereby, on the basis that the heating efficiency of the heated object arranged on the tray can be reliably improved, the heating unevenness of the heated object can be reliably suppressed.

[0013] The rear power supply portion is entirely located at an upper side than the upper end of the tray when the heating chamber is viewed from the door side. Thereby, the heating efficiency of the heated object can be improved. For example, when a reflective tray is used, and the heated objects are arranged on the reflective tray and on the bottom wall respectively, the heated objects on the reflective tray can be heated by the rear microwave source, and the heated objects on the bottom wall can be heated by the bottom microwave source respectively and individually, and thus the heating efficiency of the heated objects can be improved.

[0014] The first projection area of the bottom power supply portion extending from the bottom wall toward the top wall and the second projection area of the rear power supply portion extending from the rear wall toward the door have an overlapping area that overlaps each other. Thereby, by arranging the heated object in the overlapping area, the heating efficiency of the heated object can be effectively improved, and the heating unevenness of the heated object can be effectively suppressed.

[0015] The overlapping area is located at the center between the pair of side walls and the center between the rear wall and the door. Users mostly arrange the heated object at the center in the heating chamber, and thus, if provided as in the present mode, on the basis that the heating efficiency of the heated object can be reliably improved, the heating unevenness of the heated object can be reliably suppressed.

[0016] A heater is arranged on the top wall. In other words, since the rear power supply portion is arranged on the rear wall rather than the top wall, the heater can be arranged on the top wall. Thereby, the following combined heating process can be performed: the center of the heated object is heated by the microwaves from the microwave source, and the outer side of the heated object is heated by the radiant heat based on the heater. Thus, the convenience of the user can be improved.

[0017] The control unit repeatedly performs the following control at predetermined intervals: after activating one of the bottom microwave source and the rear microwave source and stopping the other, the control unit activates the other and stops the operation of the one. Alternatively, the control unit repeatedly performs the following control at predetermined intervals: after activating one of the multiple heating units, including the bottom microwave source, the rear microwave source, and the heater, and stopping the operation of the remaining heating units, the control unit activates a heating unit other than the activated one and stops the operation of the remaining heating units. In this case, the microwave source reaches a high temperature due to continuous operation, and therefore has a limited operating time. Therefore, for objects requiring a relatively long heating time, the inactivity time of the microwave source reduces heating efficiency. In contrast, in this method, the multiple heating units, including the bottom microwave source and the rear microwave source, are activated one by one. Therefore, when one heating unit is activated at the maximum power available, the other heating units can be inactive. Therefore, the object is always heated by one of the multiple heating units. This improves the heating efficiency of the object and shortens the total heating time compared to when multiple heating units are operated simultaneously. In addition, since the multiple heating units heat the object in different directions, uneven heating of the object can be suppressed.

[0018] Alternatively, the control unit may operate the bottom microwave source and the rear microwave source simultaneously. This reduces the power input to each microwave source compared to when only one microwave source is operated, but allows the entire object to be heated with a so-called low power, thereby suppressing uneven heating.

[0019] The tray allows the heating chamber to be divided into a lower portion below the tray and an upper portion above the tray. The microwave oven further comprises a lower temperature detector for detecting the temperature of an object in the lower portion of the heating chamber, and an upper temperature detector for detecting the temperature of an object in the upper portion of the heating chamber. This allows the bottom microwave source and the rear microwave source to be controlled based on the heating status of the objects positioned in the lower and upper portions of the heating chamber, thereby improving the heating efficiency of each object.

[0020] The control unit independently controls the bottom microwave source and the rear microwave source based on the detection results of the lower and upper temperature detection units, respectively. For example, the control unit controls the bottom microwave source based on the detection results of the lower temperature detection unit, and controls the rear microwave source based on the detection results of the upper temperature detection unit. Thus, the bottom microwave source and the rear microwave source are independently controlled based on the heating conditions of the respective objects to be heated, respectively, located in the lower and upper portions of the heating chamber. This allows each object to be reliably heated to a desired state without uneven heating.

[0021] The tray adopts the reflective tray, and the lower end of the discharge portion of the rear microwave source is arranged at a height higher than the height of the upper end of the reflective tray. Thus, by arranging the reflective tray, the transmission of microwaves between the lower part and the upper part of the heating chamber can be suppressed. In other words, the heating chamber can be essentially divided into the lower part and the upper part of the heating chamber by the reflective tray. Therefore, the heated object in the lower part of the heating chamber can be reliably heated by the bottom microwave source, and the heated object in the upper part of the heating chamber can be reliably heated by the rear microwave source. As a result, it is possible to easily construct a control program for simultaneously and individually heating different heated objects arranged in the lower part and the upper part of the heating chamber.

[0022] A heater is located below the bottom wall of the heating chamber. Radiation heat from the heater heats objects placed on a tray within the heating chamber. This improves heating efficiency and user convenience.

[0023] Effects of the Invention In the present invention, the heating efficiency of the object to be heated can be improved and heating unevenness can be suppressed with a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic cross-sectional view of a microwave oven according to a first embodiment of the present invention.

[0025] Figure 2 Cut from different directions Figure 1 Schematic cross-sectional view of a microwave oven.

[0026] Figure 3 yes Figure 1 Block diagram of a microwave oven.

[0027] Figure 4 This is a timing chart showing an example of heating control by the control unit.

[0028] Figure 5 This is a timing chart showing another example of heating control by the control unit.

[0029] Figure 6 This is a timing chart showing another example of heating control by the control unit.

[0030] Figure 7 It is a schematic cross-sectional view of a microwave oven according to a second embodiment.

[0031] Figure 8 Cut from different directions Figure 7 Schematic cross-sectional view of a microwave oven.

[0032] Figure 9 yes Figure 7 Block diagram of a microwave oven. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0034] (First embodiment) Figure 1 and Figure 2 A microwave oven 10 according to a first embodiment of the present invention is shown. Figure 1 and Figure 2 The X direction in FIG. 1 is the front-to-back direction of microwave oven 10. The direction indicated by the arrow is the rear side, and the direction opposite to the arrow is the front side. The Y direction is the width direction of microwave oven 10. The direction indicated by the arrow is the left side, and the direction opposite to the arrow is the right side. The Z direction is the height direction of microwave oven 10. The direction indicated by the arrow is the upper side, and the direction opposite to the arrow is the lower side.

[0035] Reference Figures 1 to 3 The microwave oven 10 includes a microwave oven body 12, a heating chamber 14, a door 25, and dedicated trays 40, 41, and 42 that are detachably disposed in the heating chamber 14. Furthermore, the microwave oven 10 includes a plurality of heating sections 31A, 31B, and 38, an infrared sensor 44, a thermistor 45, an operation panel 47, and a control section 50.

[0036] The multiple heating units include two magnetrons (microwave sources) 31A and 31B, and a heater 38. The control unit 50 activates one of the magnetrons 31A, 31B, and heater 38 based on the heating process selected via the operation panel 47, heating the object 1 or 2 within the heating chamber 14. In this embodiment, the power supply unit 33A of the magnetron 31A is located below the bottom wall 15 defining the heating chamber 14, and the power supply unit 33B of the magnetron 31B is located behind the rear wall 18 defining the heating chamber 14. This improves the heating efficiency of the objects 1 and 2 and reduces uneven heating. In this specification, the object 1 refers to the food placed on the trays 40 and 42, and the object 2 refers to the food placed on the bottom wall 15.

[0037] Hereinafter, the structure of the microwave oven 10 will be described in detail.

[0038] Reference Figure 1 and Figure 2 The microwave oven body 12 includes a heating chamber 14 within a housing 13. The heating chamber 14 is a rectangular parallelepiped space defined by a bottom wall 15, a top wall 16, a pair of side walls 17, a rear wall 18, and a door 25. The top wall 16 and the pair of side walls 17 are each made of metal plates that serve as microwave reflectors.

[0039] The bottom wall 15 and rear wall 18 each include a main wall portion 20 and a discharge portion 21. The main wall portion 20 is formed from a metal plate that serves as a microwave reflector and includes a recessed portion 20a that extends outward from the inside of the heating chamber 14. The discharge portion 21 is formed from ceramic, glass, or resin that serves as a microwave transmissive member and fits into the recessed portion 20a. The area occupied by the discharge portion 21 accounts for at least half (e.g., 80%) of the total area of ​​the bottom wall 15 and rear wall 18.

[0040] In order to arrange trays 40 to 42 for arranging the heated objects 1, a pair of guide rails 22 and 23 are provided on the pair of side walls 17. The lower guide rail 22 is provided in an area of ​​the pair of side walls 17 below the center of the entire height of the heating chamber 14. The upper guide rail 23 is provided in an area of ​​the pair of side walls 17 above the center of the entire height of the heating chamber 14. The guide rails 22 and 23 are formed by protruding portions of the side walls 17 into the heating chamber 14 and extending in the front-to-back direction. The number of guide rails is not limited to two sets; three or more sets may be provided.

[0041] The upper and lower guide rails 22 and the pair of lower guide rails 22 of the guide rails 23 constitute the tray holding unit of the present invention. This tray holding unit positions the trays 40-42 along the bottom wall 15 within the heating chamber 14, between the bottom power supply section 33A (more specifically, the bottom wall 15) and the rear power supply section 33B. However, the tray holding unit is not limited to the guide rails 22; it may also be a platform having legs that are separate from or integral with the trays 40-42, as long as it can position the trays 40-42 at intervals above the bottom wall 15.

[0042] Door 25 is attached to the front side of housing 13, closing the front opening of heating chamber 14 in an openable manner. Door 25 is attached to the lower portion of housing 13 and is rotatable about a rotation axis (not shown) extending in the width direction. However, door 25 may also be rotatable about a rotation axis extending in the height direction, as long as the structure can open and close the opening of heating chamber 14.

[0043] Door 25 includes a door body 26 that prevents viewing through heating chamber 14, and a window 27 that allows viewing through heating chamber 14. Door body 26 is made of a metal plate that serves as an opaque microwave reflector. Window 27 is made of glass or resin that serves as a transparent microwave transmissive material. A reflective layer 28 that reflects microwaves is provided on window 27. Reflective layer 28 is made of perforated metal with multiple holes to ensure visibility.

[0044] The bottom magnetron 31A is a heating unit that radiates microwaves into the heating chamber 14 via the bottom wall 15 to heat the objects 1 and 2 to be heated. The rear magnetron 31B is a heating unit that radiates microwaves into the heating chamber 14 via the rear wall 18 to heat the objects 1 and 2 to be heated. These magnetrons 31A and 31B are respectively arranged outside the heating chamber 14, that is, between the housing 13 and the heating chamber 14, on the lower side of the heating chamber 14, and are connected to the control unit 50 (see Figure 3 ).

[0045] More specifically, each magnetron 31A, magnetron 31B radiates microwaves into heating chamber 14 via waveguide 32A, waveguide 32B, power supply 33A, power supply 33B, and antenna 36A, antenna 36B, respectively. In the following description, magnetron 31A, magnetron 31B, waveguide 32A, waveguide 32B, power supply 33A, power supply 33B, and antenna 36A, antenna 36B are sometimes not distinguished as being for the bottom portion or for the rear portion, and are sometimes simply referred to as magnetron 31, waveguide 32, power supply 33, and antenna 36.

[0046] The waveguide 32 is made of a metal plate that serves as a microwave reflector. A bottom waveguide 32A for the bottom magnetron 31A is located below the recess 20a of the bottom wall 15, extending from the left side of the recess 20a past the center of the recess 20a. The bottom magnetron 31A is located at the left end of the bottom waveguide 32A. A rear waveguide 32B for the rear magnetron 31B is located behind the recess 20a of the rear wall 18, extending from the bottom side of the recess 20a past the center of the recess 20a. The rear magnetron 31B is located at the lower end of the rear waveguide 32B. However, the arrangement of the waveguides 32A and 32B, including the magnetrons 31A and 31B, can be modified as needed, as long as they are located within the housing 13 and between the heating chamber 14.

[0047] The power supply 33 is cylindrical and is located at the end of the waveguide 32 opposite the magnetron 31. It extends through the bottom of the recess 20a and is positioned within the recess 20a. The bottom power supply 33A for the bottom magnetron 31A is located at the center of the recess 20a in both the front-to-back and width directions of the bottom wall 15. The rear power supply 33B for the rear magnetron 31B is located at the center of the recess 20a in both the width and height directions of the rear wall 18.

[0048] Specifically describing the height arrangement of the rear power supply unit 33B, when the trays 40-42 are arranged on the guide rails 22, the rear power supply unit 33B is positioned above the upper ends of the trays 40-42. More specifically, in this embodiment, the lower end of the rear power supply unit 33B is positioned above the upper ends of the trays 40-42. However, the height arrangement of the rear power supply unit 33B only requires that a portion of the rear power supply unit 33B be positioned above the upper ends of the trays 40-42.

[0049] like Figure 1 and Figure 2The first projection area 34A of the bottom power supply portion 33A extending from the bottom wall 15 toward the top wall 16 and the second projection area 34B of the rear power supply portion 33B extending from the rear wall 18 toward the door 25 include an overlapping area 35 in which they overlap each other, as indicated by the middle double-dot chain line. The first projection area 34A refers to an area defined as extending along an axis of the bottom power supply portion 33A in the same cross-sectional shape as the bottom power supply portion 33A. The second projection area 34B refers to an area defined as extending along an axis of the rear power supply portion 33B in the same cross-sectional shape as the rear power supply portion 33B. In the present embodiment, the diameter of the bottom power supply portion 33A including the first projection area 34A is the same as the diameter of the rear power supply portion 33B including the second projection area 34B, and the axes thereof are orthogonal to each other. However, the diameters of the bottom power supply portion 33A and the rear power supply portion 33B can be different, and the cross-sectional shapes of the bottom power supply portion 33A and the rear power supply portion 33B can be different. In addition, the axes of the first projection area 34A and the second projection area 34B can be located at positions separated by an interval in the width direction of the heating chamber 14, as long as they are within the range in which the overlapping area 35 is formed.

[0050] Here, the microwave oven 10 is mostly provided in a dedicated installation space provided in a kitchen utensil rack. The depth of the installation space is determined roughly in accordance with the usability of the kitchen in which the utensil rack is installed. The height of the installation space is determined roughly in accordance with the storage property of the utensils. On the other hand, the user can select the lateral width of the utensil rack including the installation space as desired, taking into account the size of the kitchen.

[0051] The depth (dimension in the front-rear direction) and the height (dimension in the height direction) of the microwave oven 10 are determined in accordance with the dimensions of the installation space of the utensil rack. On the other hand, the lateral width of the microwave oven 10 is determined in accordance with the capacity of the heating chamber 14 formed, and becomes larger as the capacity increases, and the shape of the heating chamber 14 becomes horizontally long. That is, the invariability of the depth and the height of the microwave oven 10 is high, and the variability of the lateral width of the microwave oven 10 is high. In addition, the distance from the bottom wall 15 and the distance from the rear wall 18 are mostly closer than the distance from the side wall 17 with respect to the heated objects 1, 2 arranged in the heating chamber 14.

[0052] On the other hand, the microwaves radiated from the power supply sections 33A, 33B into the heating chamber 14 spread as they move away from the power supply sections 33A, 33B. That is, the microwaves are more easily irradiated to the heated objects 1, 2 near the power supply sections 33A, 33B, and are less easily irradiated to the heated objects 1, 2 as they move away from the power supply sections 33A, 33B. Also, in the present embodiment, the power supply sections 33A, 33B are respectively arranged at the bottom wall 15 and the rear wall 18 closer to the heated objects 1, 2 than to the side wall 17. Therefore, the microwaves can be concentrated on the heated objects 1, 2, and thus the heating efficiency of the heated objects 1, 2 can be improved. Also, since the irradiation direction of the microwaves of the bottom magnetron 31A is different from the irradiation direction of the microwaves of the rear magnetron 31B, uneven heating of the heated objects 1, 2 can be suppressed.

[0053] The antennas 36 are structures for diffusing the microwaves radiated from the power supply sections 33 into the heating chamber 14. Each of the antennas 36 is a circular plate as in the past, and is arranged between the power supply sections 33 and the discharge sections 21 in each of the recesses 20a, and is rotatable by the motors 37. The bottom motor 37A that rotates the bottom antenna 36A arranged on the upper side of the bottom power supply section 33A is arranged on the lower side of the bottom waveguide 32A. The rear motor 37B that rotates the rear antenna 36B arranged on the front side of the rear power supply section 33B is arranged on the rear side of the rear waveguide 32B. The motor shaft of each of the motors 36 penetrates the waveguide 32 and the power supply section 33, and protrudes between the power supply section 33 and the discharge section 21 in the recess 20a.

[0054] The heater 38 is arranged in the recess 16a of the top wall 16 recessed outward from the heating chamber 14, and is a heating section that heats the heated objects 1 in the heating chamber 14 by radiating heat. The heater 38 is composed of a tube heater such as a quartz tube heater, and two are arranged at intervals in the front-rear direction, and respectively extend in the width direction, and are connected to the control section 50 (see FIG. 2). Figure 3 However, the heater 38 can be arranged only one in the center of the front-rear direction of the heating chamber 14, or three or more can be arranged at intervals in the front-rear direction. Also, the heater 38 can be arranged to extend in the front-rear direction. Also, instead of the tube heater, a mica heater can be arranged on the upper surface of the recess 16a (outside the heating chamber 14).

[0055] The trays 40 to 42 are structures for arranging the heated objects 1 in the heating chamber 14, and are selectively and detachably arranged on either one of the lower guide rail 22 and the upper guide rail 23. In addition, the same or different trays 40 to 42 can be arranged on the lower guide rail 22 and the upper guide rail 23, respectively, and the heated objects 1, the heated objects 1, and the heated objects 2 can be arranged in the three regions in the heating chamber 14, respectively. One of the three trays is the heat generating tray 40, one of the remaining is the permeable tray 41, and the other of the remaining is the reflective tray 42.

[0056] The heat generating tray 40 is constructed, for example, by welding or bonding a silicon rubber containing ferrite to the lower side of an aluminum-plated steel sheet that is a microwave reflector having good thermal conductivity. The permeable tray 41 is constructed of ceramic, glass, or resin that is a microwave permeable body. The reflective tray 42 is constructed of metal that is a microwave reflector. The reflective tray 41 can also be a structure in which a reflection layer capable of reflecting microwaves is provided on the surface of a tray body constructed of a microwave permeable body such as ceramic.

[0057] The three trays 40 to 42 are each constructed of a square tray that is a quadrangular shape when viewed in the height direction, and are all provided in the same shape. However, the shapes of the trays 40 to 42 can be different. In this case, the arrangement in the height direction of the rear power supply portion 33B is preferably such that a part of the rear power supply portion 33B is positioned on the upper side of the upper end of the one having a larger height dimension between the heat generating tray 40 and the reflective tray 42.

[0058] In the case where the heat generating tray 40 is arranged in the heating chamber 14, since the heat generating tray 40 is heated by the microwaves radiated from the bottom power supply portion 33A, the heated objects 1 can be heated from the lower side surface by the heat of the heat generating tray 40, and the heated objects 1 can be heated from the inside by the microwaves radiated from the rear power supply portion 33B. For example, in the case where the heated objects 1 are heated by microwaves, water vapor generated from the heated objects (food materials) 1 tends to stay on the lower side of the heated objects 1, and there is a tendency that the processing quality of the lower side surface of the heated objects 1 deteriorates. In contrast to this, in the present embodiment, by using the heat generating tray 40, the lower side of the heated objects 1 can be heated. Therefore, the processing quality of the heated objects 1 can be improved.

[0059] In the case where the permeable tray 41 is arranged in the heating chamber 14, the heated objects 1 can be heated by the microwaves radiated from the bottom power supply portion 33A and the microwaves radiated from the rear power supply portion 33B. More specifically, the lower side of the heated objects 1 can be heated by the microwaves radiated from the bottom power supply portion 33A, and the upper side of the heated objects 1 can be heated by the microwaves radiated from the rear power supply portion 33B. Therefore, as in the case where the heat generating tray 40 is used, the processing quality of the heated objects 1 can be improved.

[0060] When the reflective tray 42 is placed within the heating chamber 14, the object 2 placed on the bottom wall 15 can be heated by microwaves radiated from the bottom power supply 33A, while the object 1 placed on the reflective tray 42 can be heated by microwaves radiated from the rear power supply 33B. If the microwave power supply is located only at the bottom, using the transparent tray 41 to heat the upper and lower objects 1 and 2, the heating efficiency of the upper object 1, farther from the power supply, is lower than that of the lower object 2, closer to the power supply. In contrast, in this embodiment, the reflective tray 42 allows the lower object 2 to be heated by microwaves radiated from the bottom power supply 33A, while the upper object 1 can be heated by microwaves radiated from the rear power supply 33B. This improves the heating efficiency when heating objects 1 and 2 placed one above the other within the heating chamber 14, and allows for independent control of the upper and lower objects 1 and 2.

[0061] Reference Figure 3 , the infrared sensor 44 is configured to detect Figure 1 The temperature detecting unit for detecting the temperature of the object 2 on the bottom wall 15 of the heating chamber 14 is connected to the control unit 50. For example, the infrared sensor 44 is a single-lens thermopile type having one infrared detection element. Figure 2 The upper guide rail 23 is shown positioned outside the side wall 17 between the upper guide rail 23 and the top wall 16, facing into the heating chamber 14 via a through-hole (not shown) formed in the side wall 17. However, the infrared sensor 44 may also be a multi-element thermopile type having multiple infrared detection elements. Furthermore, the infrared sensor 44 may be a movable type capable of changing the detection direction.

[0062] Thermistor 45 is used to detect Figure 1 The steam temperature detection unit of the steam temperature in the heating chamber 14 is connected to the control unit 50. The thermistor 45 is arranged at Figure 2 A detection unit is arranged on the upper side of the top wall 16 shown in the figure, at a corner of the heating chamber 14 defined by the top wall 16 , the rear wall 18 , and the right side wall 17 .

[0063] The operation panel 47 includes a liquid crystal panel 48 and an operation unit 49 including switches, and is connected to the control unit 50. The operation panel 47 is disposed, for example, at Figure 1 The lower side of the window portion 27 of the door 25 is shown. The liquid crystal panel 48 displays the selected state of the heating process and the execution state of the heating process based on the operation of the operation portion 49. The operation portion 49 is composed of, for example, a rotary push switch, and can select any one of a plurality of heating processes.

[0064] The control unit 50 is composed of one or more microcomputers and other electronic devices. It includes a memory 51 and a timer 52. The memory 51 stores programs for executing various heat treatments and the settings (temperature, time, etc.) used by the programs. The timer 52 measures the execution time of each heat treatment step.

[0065] The control unit 50 controls the magnetron 31A, the magnetron 31B, and the heater 38 individually according to a program determined according to the selected heating process, thereby heating the object 1 or the object 2. The heating process includes microwave heating in which only the magnetron 31A and the magnetron 31B are controlled, composite heating in which both the magnetron 31A, the magnetron 31B, and the heater 38 are controlled, and heater heating in which only the heater 38 is controlled.

[0066] Microwave heating treatment includes a lower range, an upper range, and an upper and lower range. The lower range is performed with the object to be heated 2 placed on the bottom wall 15 of the heating chamber 14. The upper range is performed with the object to be heated 1 placed on the heating tray 40 or the transparent tray 41. The upper and lower ranges are performed with the object to be heated 2 placed on the bottom wall 15 and the object to be heated 1 placed on any of the trays 40 to 42. In these microwave heating treatments, the control unit 50 controls the magnetron 31A and the magnetron 31B based on the detection results of the infrared sensor 44 and the thermistor 45, respectively, to heat the objects to be heated 1 and 2 using microwaves.

[0067] The combined heating process is performed with the object 1 placed on the heating tray 40 or the transparent tray 41. In this combined heating process, the control unit 50 controls the magnetrons 31A and 31B and the heater 38 based solely on the detection results of the thermistor 45, heating the object 1 using microwaves and radiant heat.

[0068] The heater heating process is performed with the object 1 placed on the transmissive tray 41 or the reflective tray 42. In the heater heating process, the control unit 50 controls the heater 38 based solely on the detection result of the thermistor 45 to heat the object 1 by radiant heat.

[0069] Hereinafter, an example of control by the control unit 50 in the microwave heating process and the combined heating process will be described in detail.

[0070] Figure 4The following illustrates an example of control by the controller 50 over the magnetrons 31A and 31B during microwave heating. In this example, the controller 50 repeats, at predetermined intervals of time t, a first step in which the bottom magnetron 31A is activated and the rear magnetron 31B is deactivated, and a second step in which the rear magnetron 31B is activated and the bottom magnetron 31A is deactivated. However, the rear magnetron 31B may be activated in the first step and the bottom magnetron 31A in the second step. Specifically, the controller 50 repeats, at predetermined intervals of time t, control of the following: activating one of the bottom magnetron 31A and the rear magnetron 31B and deactivating the other, then activating the other and deactivating the first.

[0071] exist Figure 4 In the control shown, the power supplied to one magnetron 31A or magnetron 31B is the maximum power that can be supplied (e.g., 1000 W). Furthermore, the set time t for switching the operation of magnetrons 31A and 31B is set within a range of 3 to 5 minutes. If the set time t is too long, the temperatures of magnetrons 31A and 31B will increase. On the other hand, if the set time t is too short, the heating efficiency of the objects 1 and 2 will decrease. To prevent these problems, the set time t for each operation of magnetrons 31A and 31B is preferably set within the above-specified range. Furthermore, this configuration improves heating efficiency and shortens the total heating time when heating the objects 1 and 2 requires a relatively long time. Furthermore, the microwave irradiation direction of the bottom magnetron 31A differs from that of the rear magnetron 31B, thereby suppressing uneven heating of the objects 1 and 2.

[0072] Figure 5 Another example of control of the magnetrons 31A and 31B by the control unit 50 during microwave heating is shown. In this example, the control unit 50 operates both the bottom magnetron 31A and the rear magnetron 31B simultaneously. In this control, based on the maximum power consumption, both magnetrons 31A and 31B are operated at a power level (e.g., 350 W) that is less than half the maximum power (1000 W) that can be supplied when only one magnetron 31A or 31B is in operation. However, the power supplied to one magnetron 31A or 31B may be different from the power supplied to the other.

[0073] Figure 6The following is an example of the control of the magnetron 31A, the magnetron 31B, and the heater 38 by the control unit 50 in the composite heating process. In this example, the control unit 50 repeatedly performs the first process of operating the bottom magnetron 31A and stopping the operation of the rear magnetron 31B and the heater 38, the second process of operating the rear magnetron 31B and stopping the operation of the bottom magnetron 31A and the heater 38, and the third process of operating the heater 38 and stopping the operation of the two magnetrons 31A and 31B at set time intervals t. That is, the control unit 50 repeatedly performs the following control at set time intervals t: after operating one of the multiple heating units including the two magnetrons 31A, the magnetron 31B, and the heater 38 and stopping the operation of the remaining heating units, it operates a heating unit other than the operating one and stops the operation of the remaining heating units. However, the order of operating the magnetron 31A, the magnetron 31B, and the heater 38 can be changed as needed. In addition, the set time t for the switching operation is different from the set time t for the switching operation. Figure 4 In addition, in the composite heating process, it is also possible to Figure 5 As shown in the control, the magnetron 31A, the magnetron 31B and the heater 38 are all operated simultaneously.

[0074] exist Figure 4 and Figure 6 In the control shown, one of the magnetron 31A, magnetron 31B and heater 38 can be operated with the maximum power that can be input, so Figure 5 Compared with the control shown in FIG. 1 , the heating efficiency of the object 1 can be improved and the total time required for heating can be shortened. Figure 5 In the control shown, Figure 4 and Figure 6 Compared with the control shown, the power that can be input to each of the magnetrons 31A and 31B is lower, but the entire object 1 can be heated with so-called low heat, so that uneven heating can be suppressed.

[0075] The microwave oven 10 configured as described above has the following features.

[0076] Microwave-radiating power supply sections 33A and 33B are located below the bottom wall 15 and behind the rear wall 18, respectively. Because the bottom wall 15 and rear wall 18 are located close to the object 1, microwaves that diffuse as they move away from the power supply sections 33A and 33B are concentrated on the object 1. This allows for improved heating efficiency of the objects 1 and 2 with a simple structure. Furthermore, since the microwave irradiation directions of magnetron 31A and magnetron 31B are different, the control unit 50 allows independent control of the two magnetrons 31A and 31B, thereby minimizing uneven heating of the objects 1 and 2.

[0077] The tray positioned between the bottom power supply section 33A and the rear power supply section 33B within the heating chamber 14 includes a heating tray 40 that generates heat through microwaves radiated from the bottom power supply section 33A. This allows the object 1 to be heated from its lower surface by the heat from the heating tray 40, while the object 1 can be heated from the inside by microwaves radiated from the rear power supply section 33B. This improves heating efficiency for the object 1 and reduces uneven heating of the object 1.

[0078] The tray disposed between the bottom wall 15 and the rear power supply section 33B within the heating chamber 14 includes a translucent tray 41 that allows microwaves to pass through. This allows the object 1 to be heated by both the microwaves radiated from the bottom power supply section 33A and the microwaves radiated from the rear power supply section 33B. This improves the heating efficiency of the object 1 while minimizing uneven heating of the object 1.

[0079] The tray positioned between the bottom wall 15 and the rear power supply section 33B within the heating chamber 14 includes a reflective tray 42 that reflects microwaves. This allows microwaves radiated from the bottom power supply section 33A to heat the object 2 placed on the bottom wall 15, while microwaves radiated from the rear power supply section 33B to heat the object 1 placed on the reflective tray 42. This allows simultaneous and independent heating of the objects 1 and 2, improving heating efficiency and user convenience.

[0080] At least a portion of the rear power supply unit 33B is located above the upper ends of the trays 40 to 42. This ensures that the heating efficiency of the objects 1 placed on the trays 40 to 42 is increased while also preventing uneven heating of the objects 1.

[0081] The rear power supply units 33B are all located above the upper ends of the trays 40 to 42. This reliably improves the heating efficiency of the objects 1 placed on the trays 40 to 42. For example, when using a reflective tray 42, with the objects 1 and 2 placed on the reflective tray 42 and bottom wall 15, respectively, the rear magnetron 31B can heat the object 1 on the reflective tray 42, while the bottom magnetron 31A can heat the object 2 on the bottom wall 15, respectively. This improves the heating efficiency of the objects 1 and 2.

[0082] The first projected area 34A of the bottom power supply portion 33A and the second projected area 34B of the rear power supply portion 33B overlap each other in an overlapping area 35. Thus, by arranging the object 1 in the overlapping area 35, the heating efficiency of the object 1 can be effectively improved while effectively suppressing uneven heating of the object 1.

[0083] The overlapping region 35 is located in the center between the pair of side walls 17 and in the center between the rear wall 18 and the door 25. Since users often place the object 1 in the center of the heating chamber 14, the heating efficiency of the object 1 can be reliably improved while uneven heating of the object 1 can be reliably suppressed.

[0084] Since rear power supply unit 33B is disposed on rear wall 18 rather than top wall 16, heater 38 can be disposed on top wall 16. This allows for a combined heating process in which the center of object 1 is heated by microwaves from magnetrons 31A and 31B, while the outer side of object 1 is heated by radiant heat from heater 38. This improves user convenience.

[0085] The control unit 50 repeatedly performs the following control at predetermined intervals t: after activating one of the magnetrons 31A and 31B and stopping the other, it then activates the other and stops the one. Alternatively, the control unit 50 repeatedly performs the following control at predetermined intervals t: after activating one of the multiple heating units including the magnetrons 31A, 31B, and heater 38 and stopping the remaining heating units, it activates a heating unit other than the activated one and stops the remaining heating units. Since the magnetrons 31A and 31B reach high temperatures due to continuous operation, their operating time is limited. Therefore, for objects 1 and 2 requiring relatively long heating times, ensuring that the magnetrons 31A and 31B are idle reduces heating efficiency. In contrast, in this embodiment, the multiple heating units, including magnetrons 31A and 31B, are operated one by one. Therefore, when magnetron 31A or 31B is operating at the maximum power available, the other magnetrons 31A or 31B can be deactivated. Consequently, compared to operating multiple heating units simultaneously, the heating efficiency of the object 1 or 2 can be improved, and the total heating time can be shortened. Furthermore, the microwave irradiation directions of magnetron 31A and magnetron 31B differ, thereby minimizing uneven heating of the objects 1 and 2.

[0086] Alternatively, the control unit 50 can operate the magnetrons 31A and 31B simultaneously. This reduces the power input to each magnetron 31A and 31B compared to operating the magnetrons 31A and 31B alternately. However, the objects 1 and 2 can be heated entirely with so-called low heat, thereby reducing uneven heating.

[0087] Hereinafter, other embodiments and various modifications of the present invention will be described, but in these descriptions, points not specifically mentioned are the same as those of the first embodiment. In the drawings mentioned below, the same reference numerals are given to the same elements as those of the first embodiment.

[0088] (Second embodiment) Reference Figures 7 to 9 The microwave oven 10 of the second embodiment differs from the microwave oven 10 of the first embodiment in that an intermediate rail 24 is provided in addition to the upper and lower rails 22 and 23; the configuration of the microwave emission portion 21 radiated by the magnetron 31B at the rear is changed; and infrared sensors 44A and 44B are installed for separately detecting the temperatures of the objects to be heated 2 and 1.

[0089] The middle rails 24, like the lower rails 22 and upper rails 23, are used to accommodate trays 40 to 42, which accommodate the heated objects 1. The middle rails 24 are provided at the same height between the lower rails 22 and the upper rails 23 in the pair of side walls 17.

[0090] A pair of intermediate guide rails 24 are arranged so that the bottom surfaces of trays 40 to 42 are located approximately in the center of the entire height of heating chamber 14. A pair of lower guide rails 22 are arranged between intermediate guide rails 24 and bottom wall 15. A pair of upper guide rails 23 are arranged between intermediate guide rails 24 and top wall 16. Guide rails 22 to 24 are each formed into a right triangle shape with the upper end extending along the XY plane. In the second embodiment, the pair of intermediate guide rails 24, among the three types of guide rails 22 to 23, constitute the tray holding unit of the present invention for arranging trays 40 to 42 along bottom wall 15 in heating chamber 14.

[0091] The placement of trays 40 and 42 on intermediate rails 24 divides heating chamber 14 into a lower heating chamber portion 14A located below trays 40 and 42 and an upper heating chamber portion 14B located above trays 40 and 42. The placement of heating trays 40 or reflective trays 42 on intermediate rails 24 suppresses the transmission of microwaves between lower heating chamber portion 14A and upper heating chamber portion 14B. The placement of transmissive trays 41 on intermediate rails 24 allows the transmission of microwaves between lower heating chamber portion 14A and upper heating chamber portion 14B.

[0092] As in the first embodiment, the bottom wall 15 and the rear wall 18 are both composed of a wall main body 20 and a discharge portion 21. As in the first embodiment, the wall main body 20 of the bottom wall 15 includes a recess 20a formed so that the ratio of the area occupied by the discharge portion 21 to the total area is at least half (e.g., 80%). Meanwhile, in the wall main body 20 of the rear wall 18 of the second embodiment, the recess 20a is formed so that the lower end 21a of the discharge portion 21 is at the same height as the upper ends of the trays 40 to 42 arranged on the middle rail 24. However, the lower end 21a of the discharge portion 21 may also be arranged at a position higher than the upper ends of the trays 40 to 42 arranged on the middle rail 24.

[0093] As in the first embodiment, magnetrons 31A and 31B radiate microwaves into heating chamber 14 via waveguides 32A and 32B, power feeders 33A and 33B, and antennas 36A and 36B, respectively. However, rear waveguide 32B of rear magnetron 31B differs from rear waveguide 32B of the first embodiment only in that it extends upward so as to be located in the center of recess 20a of rear wall 18.

[0094] The heater 38 of the second embodiment is a sheet-shaped mica heater. The recess 16a is not provided in the ceiling wall 16, but is laid on the upper side of the flat ceiling wall 16 (outside the heating chamber 14). However, the upper heater 38 disposed on the upper side of the ceiling wall 16 may be a tube heater similar to the first embodiment, or an Inkloy heater.

[0095] In the second embodiment, a heater 39 is further installed in the recess 20a of the bottom wall 15. The lower heater 39 is composed of a tube heater arranged in the recess 20a so as to surround the bottom antenna 36A and is connected to the control unit 50 (see Figure 9 However, the lower heater 39 may also be formed of an Incoloy heater or a mica heater.

[0096] The infrared sensor 44A and the infrared sensor 44B are installed on one side of the pair of side walls 17 at a distance therebetween. Figure 8 The outside of the right side is connected to the control unit 50 (refer to Figure 9 ). More specifically, the lower infrared sensor 44A is a lower temperature detection unit for detecting the temperature of the object to be heated 2 arranged in the lower portion 14A of the heating chamber, that is, on the bottom wall 15. The lower infrared sensor 44A is arranged in one of the recesses of the pair of middle guide rails 24 in a manner capable of detecting the object to be heated 2 arranged in the center of the bottom wall 15, and faces the inside of the heating chamber 14 through a through-hole (not shown). The upper infrared sensor 44B is an upper temperature detection unit for detecting the temperature of the object to be heated 1 arranged in the upper portion 14B of the heating chamber, that is, on the trays 40 to 42. The upper infrared sensor 44B is arranged on the outer side of the side wall 17 between the upper guide rail 23 and the top wall 16 in a manner capable of detecting the object to be heated 1 arranged in the center of the trays 40 to 42, and faces the inside of the heating chamber 14 through a through-hole (not shown).

[0097] As in the first embodiment, the control unit 50 individually controls the magnetrons 31A and 31B and the heaters 38 and 39 according to a program determined according to the selected heating process, thereby executing microwave heating, combined heating, and heater heating. Furthermore, in the second embodiment, since the temperatures of the objects 2 and 1 can be detected by infrared sensors 44A and 44B, respectively, the control unit 50 can perform precise control when simultaneously and individually heating the objects 2 and 1 in the lower heating chamber 14A and the upper heating chamber 14B using microwave heating, as will be described in detail in an example below.

[0098] A reflective tray 42 is placed on the middle guide rail 24. When the objects 2 and 1 are heated simultaneously to a target temperature T1 (e.g., 70°C) in the lower and upper heating chambers 14A and 14B, the control unit 50 sets a confirmation temperature T2 (e.g., 60°C) based on the target temperature T1. The control unit 50 first controls the bottom magnetron 31A based on the detection results of the lower infrared sensor 44A and the rear magnetron 31B based on the detection results of the upper infrared sensor 44B. If the object 2 in the lower heating chamber 14A reaches the confirmation temperature T2, but the object 1 in the upper heating chamber 14B does not, the control unit 50 controls the power input to the bottom magnetron 31A to decrease (reducing the heating power) and controls the power input to the rear magnetron 31B to increase (increasing the heating power). In other words, if the control unit 50 determines based on the detection results of the infrared sensor 44A and the infrared sensor 44B that one of the upper and lower heated objects 2 and the heated object 1 is heated to the confirmation temperature T2 and the other is not heated to the confirmation temperature T2, the input power of the magnetron 31A or the magnetron 31B of the heated side is reduced, and the input power of the magnetron 31A or the magnetron 31B of the other side that is not heated is increased.

[0099] Alternatively, the control unit 50 may perform control as follows. If there is a possibility that microwaves from the rear magnetron 31B may affect the object 2 to be heated in the lower portion 14A of the heating chamber, the rear magnetron 31B may be controlled based on the detection result of the lower infrared sensor 44A. On the other hand, if there is a possibility that microwaves from the bottom magnetron 31A may affect the object 1 to be heated in the upper portion 14B of the heating chamber, the bottom magnetron 31A may be controlled based on the detection result of the upper infrared sensor 44B.

[0100] In other words, the control unit 50 independently controls the bottom magnetron 31A and the rear magnetron 31B based on the detection results of the lower infrared sensor 44A and the upper infrared sensor 44B. This allows the heating conditions of the object 2 in the lower heating chamber 14A and the object 1 in the upper heating chamber 14B to be aligned, and both objects can be heated to the target temperature T1 simultaneously.

[0101] The microwave oven 10 of the second embodiment also includes a heater 39 below the bottom wall 15. Therefore, during the combined heating process or the heater heating process, the objects 1 on the trays 40 and 42 can be heated by the radiant heat of the lower heater 39.

[0102] The microwave oven 10 of the second embodiment configured as described above has the following features.

[0103] The heating chamber includes a lower infrared sensor 44A for detecting the temperature of the object 2 to be heated within the lower heating chamber portion 14A, and an upper infrared sensor 44B for detecting the temperature of the object 1 to be heated within the upper heating chamber portion 14B. This allows the bottom magnetron 31A and the rear magnetron 31B to be controlled based on the heating conditions of the objects 2 and 1 positioned in the lower heating chamber portion 14A and the upper heating chamber portion 14B, respectively. This improves the heating efficiency of the objects 2 and 1.

[0104] The control unit 50 independently controls the bottom magnetron 31A and the rear magnetron 31B based on the detection results of the lower infrared sensor 44A and the upper infrared sensor 44B, respectively. For example, the control unit 50 controls the bottom magnetron 31A based on the detection results of the lower infrared sensor 44A and controls the rear magnetron 31B based on the detection results of the upper infrared sensor 44B. In this way, the bottom magnetron 31A and the rear magnetron 31B are independently controlled according to the heating conditions of the respective objects to be heated, which are arranged in the lower heating chamber 14A and the upper heating chamber 14B. This ensures that each object to be heated is heated reliably to the desired state without uneven heating.

[0105] The lower end 21a of the discharge portion 21 of the rear magnetron 31B is positioned at a height above the upper end of the reflective tray 42. Thus, the placement of the reflective tray 42 suppresses the transmission of microwaves between the lower heating chamber 14A and the upper heating chamber 14B. In other words, the reflective tray 42 effectively divides the interior of the heating chamber 14 into the lower heating chamber 14A and the upper heating chamber 14B. Therefore, the bottom magnetron 31A can reliably heat the object 2 in the lower heating chamber 14A, while the rear magnetron 31B can reliably heat the object 1 in the upper heating chamber 14B. As a result, it is easy to construct a control program for simultaneously and independently heating the different objects 2 and 1 arranged in the lower heating chamber 14A and the upper heating chamber 14B.

[0106] A heater 39 is disposed below the bottom wall 15 of the heating chamber 14. The radiant heat from the heater 39 heats the objects 1 placed on the trays 40 to 42 in the heating chamber 14. This improves heating efficiency for the objects 1 and enhances user convenience.

[0107] In addition, the present invention is not limited to the configuration of the above-described embodiment, and various modifications can be made.

[0108] For example, three or more magnetrons may be used as the heating unit, or a configuration may be employed in which heaters 38 and 39 are not used. Furthermore, in the microwave oven 10 of the second embodiment, the upper heater 38 may be omitted and only the lower heater 39 may be installed. When heater 38 is omitted, the magnetron power supply unit may be disposed on the top wall 16 separately from the bottom power supply unit 33A and the rear power supply unit 33B. Alternatively, the power supply unit may be disposed on the side wall 17 separately from the bottom power supply unit 33A and the rear power supply unit 33B. When power supply units are provided in locations other than the bottom wall 15 and the rear wall 18, the waveguides 32A and 32B may be branched, and the magnetrons 31A and 31B may be shared, or dedicated waveguides and magnetrons may be used.

[0109] A plurality of emission portions 21 for radiating microwaves into the heating chamber 14 may be provided on each of the bottom wall 15 and the rear wall 18 .

[0110] When a tray is used to place the heated object 1, the tray may be only one of the heating tray 40, the transparent tray 41, and the reflective tray 42, or two. In other words, any structure including at least one of the heating tray 40, the transparent tray 41, and the reflective tray 42 will suffice.

[0111] The first projection area 34A of the bottom power supply portion 33A and the second projection area 34B of the rear power supply portion 33B may be arranged without overlapping area 35. Of course, the bottom power supply portion 33A and the rear power supply portion 33B may each be arranged at a location other than the center between the pair of side walls 17 and the center between the rear wall 18 and the door 25.

[0112] The control of the magnetron 31A, the magnetron 31B, and the heater 38 by the control unit 50 can be changed as needed as long as the structure can heat the object 1 or the object 2 efficiently without heating unevenness.

[0113] Description of Reference Numerals 1.2 Objects to be heated 10. Microwave 12 Microwave oven body 13 Housing 14 Heating Chamber 14A Heating chamber lower part 14B Upper part of heating chamber 15 bottom wall 16 Top wall 16a recess 17 Sidewall 18 posterior wall 20 Wall main body 20a recess 21 Release section 21a Lower end 22 Lower guide rail (tray holding unit of the first embodiment) 23 Upper guide rail 24 Middle rail (tray holding unit of the second embodiment) 25 doors 26 Door body 27 Window 28 Reflection layer 31A Bottom magnetron (heating unit, bottom microwave source) 31B rear magnetron (heating unit, rear microwave source) 32A bottom waveguide 32B rear waveguide 33A bottom power supply 33B rear power supply unit 34A First projection area 34B Second projection area 35 overlapping areas 36A bottom antenna 36B rear antenna 37A bottom motor 37B rear motor 38. Heater (heating unit) 39 Lower heater 40 Heating Tray 41 Permeable Tray 42 Reflective Tray 44 infrared sensors 44A Lower infrared sensor (lower temperature detection unit) 44B Upper infrared sensor (upper temperature detection unit) 45 Thermistor 47 Operation Panel 48 LCD panel 49 Operation Department 50 Control Department 51 Memory 52 timer.

Claims

1. A microwave oven comprising: The heating chamber is defined by a bottom wall, a top wall, a pair of side walls, a rear wall and a door; A microwave source for the bottom and a microwave source for the rear are respectively arranged outside the heating chamber; a bottom power supply portion, disposed on the lower side of the bottom wall, radiating the microwaves emitted by the bottom microwave source into the heating chamber via the bottom wall; a rear power supply unit, disposed on the rear side of the rear wall, radiating the microwaves emitted by the rear microwave source into the heating chamber via the rear wall; as well as The control unit controls the bottom microwave source and the rear microwave source individually.

2. The microwave oven according to claim 1, wherein A tray holding unit is provided between the bottom power supply unit and the rear power supply unit in the heating chamber, and the tray holding unit is used to arrange the tray for placing the heated object along the bottom wall. The tray includes at least one of a heat-generating tray capable of generating heat through microwaves, a transmissive tray capable of transmitting microwaves, and a reflective tray capable of reflecting microwaves.

3. The microwave oven according to claim 2, wherein: When the heating chamber is viewed from the door side, at least a portion of the rear power supply unit is located above an upper end of the tray.

4. The microwave oven according to claim 3, wherein: When the heating chamber is viewed from the door side, the entire rear power supply portion is located above the upper end of the tray.

5. The microwave oven according to any one of claims 1 to 4, wherein A first projection area of ​​the bottom power supply portion extending from the bottom wall toward the top wall and a second projection area of ​​the rear power supply portion extending from the rear wall toward the door have an overlapping area that overlaps with each other.

6. The microwave oven according to claim 5, wherein The overlapping area is located centrally between the pair of side walls and centrally between the rear wall and the door.

7. The microwave oven according to any one of claims 1 to 4, wherein A heater is arranged on the top wall.

8. The microwave oven according to any one of claims 1 to 4, wherein The control unit repeatedly performs control at predetermined time intervals to operate one of the bottom microwave source and the rear microwave source and stop the other, and then operate the other and stop the one.

9. The microwave oven according to claim 7, wherein: The control unit repeatedly performs the following control at predetermined intervals: after operating one of the plurality of heating units including the bottom microwave source, the rear microwave source, and the heater and stopping the operations of the remaining heating units, operating one heating unit other than the operating one heating unit and stopping the operations of the remaining heating units.

10. The microwave oven according to any one of claims 1 to 4, wherein The control unit operates the bottom microwave source and the rear microwave source simultaneously.

11. The microwave oven according to any one of claims 2 to 4, wherein: The tray can be used to partition the heating chamber into a lower portion of the heating chamber below the tray and an upper portion of the heating chamber above the tray. The microwave oven further comprises: a lower temperature detection unit for detecting the temperature of the object to be heated in the lower portion of the heating chamber; and The upper temperature detection unit detects the temperature of the object to be heated in the upper portion of the heating chamber.

12. The microwave oven according to claim 11, wherein The control unit independently controls the bottom microwave source and the rear microwave source based on respective detection results of the lower temperature detection unit and the upper temperature detection unit.

13. The microwave oven according to claim 12, wherein: The control unit controls the bottom microwave source based on a detection result of the lower temperature detection unit, and controls the rear microwave source based on a detection result of the upper temperature detection unit.

14. The microwave oven according to claim 11, wherein The tray adopts the reflective tray, The lower end of the emitting portion of the rear microwave source is arranged at a height higher than that of the upper end of the reflective tray.

15. The microwave oven according to any one of claims 1 to 4, wherein A heater is disposed on a lower side of the bottom wall of the heating chamber.

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