JP3970115B2 - microwave - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooking apparatus, and more particularly to a microwave oven that heats food by high frequency.
[0002]
[Prior art]
A conventional microwave oven includes a magnetron that supplies a microwave, and a waveguide that guides the microwave generated by the magnetron to a heating chamber. For example, some conventional microwave ovens are supplied with microwaves from the side surface of the heating chamber, while others are supplied with microwaves from the bottom surface of the heating chamber.
[0003]
Some conventional microwave ovens include a coaxial antenna that exists between the waveguide and the heating chamber, and a radiation antenna that is attached to the end of the coaxial antenna on the heating chamber side. In such a microwave oven, microwaves are diffused by the radiation antenna and supplied to the heating chamber. In addition, in order to uniformly heat the food in the heating chamber, the radiation antenna may be rotated and microwaves may be supplied evenly in the heating chamber.
[0004]
[Problems to be solved by the invention]
However, in the conventional microwave oven, when the food is heated, in particular, when the food having the thickness of the whole potato or the like is heated, the whole food is uniformly distributed if microwaves are supplied from only one side. In some cases, it could not be heated. Moreover, in the conventional microwave oven, even when microwaves are supplied from the bottom, for example, when a flat and large surface area food is heated, the whole food may not be heated uniformly. In other words, there are cases where the food cannot be heated so that the user can be satisfied.
[0005]
Some conventional microwave ovens further include a heater for heating the heater. In such a case, it is necessary to avoid deformation of the radiating antenna due to heat generated by the heater. When the radiating antenna is deformed, the pattern of microwave diffusion from the radiating antenna to the heating chamber changes, and the microwaves are not supplied evenly in the heating chamber, and the food cannot be heated so that the user can be satisfied. This is because it is assumed.
[0006]
The present invention has been conceived in view of such circumstances, and an object thereof is to provide a microwave oven that can heat food so that a user can be satisfied.
[0007]
[Means for Solving the Problems]
A microwave oven according to an aspect of the present invention includes a heating chamber containing food, A door capable of opening and closing the front surface of the heating chamber, a bottom plate disposed in the heating chamber for placing food contained in the heating chamber, a magnetron that oscillates microwaves, and a microwave oscillated by the magnetron A waveguide disposed in the lower portion of the heating chamber to guide the heating chamber to the heating chamber, and a rotation shaft disposed from the waveguide to the heating chamber, respectively, below the bottom plate, Two radiating antennas arranged so as to be lined up in the left-right direction when viewed from the door, an antenna motor attached to the rotating shaft and rotating the radiating antenna by rotating the rotating shaft, and the rotating shafts A motor for changing the penetration length penetrating into the waveguide, and a controller for controlling the operation of the magnetron, the antenna motor, and the motor for changing the penetration length. The motor for changing the intrusion length is configured so that the intrusion length of the other rotation shaft is longer than the intrusion length of one of the rotation shafts, so that a radiation antenna attached to the other rotation shaft The microwaves to be radiated are radiated more than the microwaves radiated from the radiating antenna attached to the one rotating shaft, and the penetration lengths of the rotating shafts are the same, so that the rotating shafts are attached to the rotating shafts. The microwave radiated from the radiating antenna is radiated to the same extent, and the control unit changes the pattern for supplying the microwave into the heating chamber by operating a motor for changing the penetration depth. It is characterized by that.
[0012]
According to another aspect of the present invention, in a microwave oven, microwaves are supplied to a heating chamber from a plurality of radiating antennas. That is, microwaves are supplied to the heating chamber from more places than before without increasing the number of magnetrons.
[0013]
Thereby, since microwaves can be supplied evenly into the heating chamber, the heating unevenness of the food can be suppressed and the food can be heated to satisfy the user without increasing the cost of the microwave oven itself.
[0014]
In the microwave oven according to the present invention, The magnetron is disposed behind the heating chamber, and the waveguide is double-handed so that it can accommodate the rotating shafts. It is preferable to have a branched structure.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
FIG. 1 is a perspective view of the microwave oven according to the first embodiment of the present invention.
[0020]
With reference to FIG. 1, a microwave oven 1 mainly includes a main body 2 and a door 3. The main body 2 is covered with an exterior part 4 at its outer shell. An operation panel 6 is provided on the front surface of the main body 2 so that the user can input various information to the microwave oven 1. The main body 2 is supported by a plurality of legs 8. The door 3 is configured to be openable and closable with the lower end as an axis. A handle 3 </ b> A is provided on the upper portion of the door 3. 2 is a cross-sectional view taken along the line II-II in FIG.
[0021]
A main body frame 5 is provided inside the main body 2. A heating chamber 10 is provided inside the main body frame 5. The heating chamber 10 is configured to be opened and closed by the door 3. A detection path member 40 is connected to the upper right side of the heating chamber 10. A detection window 11 is formed on a box-shaped bottom surface constituting the detection path member 40. The infrared sensor 7 catches infrared rays in the heating chamber 10 through the detection window 11.
[0022]
A bottom plate 9 is provided in the heating chamber 10. In the heating chamber 10, food to be heated is placed on the bottom plate 9.
[0023]
A magnetron 12 is provided inside the exterior portion 4 so as to be adjacent to the lower right of the heating chamber 10. A waveguide 19 that connects the magnetron 12 and the lower part of the main body frame 5 is provided below the heating chamber 10. The waveguide 19 corresponds to the first waveguide of the present invention.
[0024]
An antenna motor 16 is attached to the lower surface of the waveguide 19. A rotation shaft 15 </ b> A is provided from the waveguide 19 to the inside of the heating chamber 10. The rotation shaft 15A is fixed to the antenna motor 16 by a support member 16A so as to be rotatable in the arrow R direction. A radiating antenna 15 is attached to the end of the rotating shaft 15 </ b> A on the heating chamber 10 side so as to exist between the bottom of the main body frame 5 and the bottom plate 9. The radiation antenna 15 and the antenna motor 16 are connected by a rotating shaft 15A and a support member 16A. Then, when the antenna motor 16 is driven, the radiation antenna 15 is rotated. A bearing 15B is provided on the bottom surface of the main body frame 5, and the rotating shaft 15A is installed in the bearing 15B.
[0025]
The high frequency emitted by the magnetron 12 is supplied into the heating chamber 10 through the waveguide 19 while being stirred by the radiation antenna 15. Thereby, the food on the bottom plate 9 is heated.
[0026]
In order to efficiently guide the microwave oscillated by the magnetron 12 into the heating chamber 10, the distance LA from the magnetron antenna 12A of the magnetron 12 to the end portion of the waveguide 19 in the traveling direction of the microwave is When the wavelength is λ, it is preferably an integral multiple of “λ / 2”, that is, the following equation (1).
[0027]
LA = (λ / 2) × n (n is an integer) (1)
Further, the distance LB from the end of the waveguide 19 to the rotating shaft 15A is preferably ¼ of λ.
[0028]
A waveguide 50 corresponding to the second waveguide of the present invention is provided on the right side of the heating chamber 10. The waveguide 50 is a tube extending from the inlet 50 </ b> A to the outlet 50 </ b> B, and is provided so as to connect a portion below the bottom plate 9 and a portion above the bottom plate 9 in the heating chamber 10. In the heating chamber 10, holes having the same shape are formed at positions where the inlet 50A and the outlet 50B are connected. In the microwave oven 1, the waveguide 50 is provided, so that the microwave oscillated by the magnetron 12 is guided from the inlet 50 </ b> A to the outlet 50 </ b> B. That is, by providing the waveguide 50, the food in the heating chamber 10 is supplied with the microwaves oscillated by the magnetron 12 not only from below but also from above. From such a point of view, the outlet 50B is provided at the upper part of the heating chamber 10, preferably at a position that is 1/2 or more of the height of the heating chamber 10, and more preferably 2/3 or more of the height of the heating chamber 10. It is preferable that it is attached to the position. In addition, regarding the size (diameter) of the outlet 50B, it is considered that the larger the outlet 50B is, the more efficiently the microwave in the waveguide 50 is guided to the heating chamber 10, but there is no particular limitation.
[0029]
FIG. 3 is an enlarged view around the lower portion of the heating chamber 10 of FIG. Here, with reference to FIG. 3, the progress of the microwave guided to the heating chamber 10 via the waveguide 19 is schematically shown by white arrows. In FIG. 3, among the microwaves guided into the heating chamber 10 through the waveguide 19, those guided to the vicinity of the introduction port 50 </ b> A are transmitted from the outlet 50 </ b> B through the waveguide 50 to the heating chamber. 10 is led to the top.
[0030]
In order to efficiently guide the microwave to the waveguide 50, the dimension LC of the introduction port 50A in the direction intersecting the microwave traveling direction is preferably 8 cm or more.
[0031]
FIG. 4 shows a first modification of the microwave oven 1 shown in FIGS. 1 and 2 of the present embodiment. In the microwave oven 1 shown in FIG. 4, the introduction port 50 </ b> A of the waveguide 50 is connected to the lower surface of the heating chamber 10. As shown in FIGS. 2 and 4, the introduction port 50 </ b> A of the waveguide 50 may be connected to the side surface or connected to the lower surface of the heating chamber 10. Further, the outlet 50B of the waveguide 50 may be connected not only to the side surface of the heating chamber 10, but also to the top surface or the back surface (the surface in the back as viewed from the door 3 side), or across a plurality of surfaces. It may be connected.
[0032]
In the example shown in FIG. 4, the microwave guided to the vicinity of the introduction port 50 </ b> A travels downward when guided into the waveguide 50. Then, the dimension LD in the direction intersecting the microwave traveling direction (downward in FIG. 4) of the introduction port 50A in the example shown in FIG. 4 is preferably 8 cm or more, like LC.
[0033]
FIG. 5 is a diagram illustrating a second modification of the microwave oven 1 according to the present embodiment, and FIG. 6 is an enlarged view of the vicinity of the lower portion of the heating chamber 10 in FIG. Also in FIG. 6, the traveling direction of the microwave is schematically shown by a white arrow.
[0034]
In the second modification, a reflecting plate 51 is provided in the vicinity of the introduction port 50A, which exists from the heating chamber 10 to the inside of the waveguide 50 and is made of a dielectric. Thereby, the microwave guided to the vicinity of the introduction port 50A is guided into the waveguide 50 more efficiently.
[0035]
In the present embodiment, the radiating antenna 15 is attached to the rotating shaft 15A at a portion other than the center. Specifically, as shown in FIG. 6, the radiating antenna 15 includes end portions 15X and 15Y. The distances from the points on the radiation antenna 15 corresponding to the rotation center of the rotation shaft 15A of the end portions 15X and 15Y are indicated as LX and LY (LX> LY), respectively.
[0036]
In FIG. 6, the end 15X is located in the vicinity of the introduction port 50A. In this state, the microwave guided to the radiating antenna 15 is easily guided into the waveguide 50 through the end 15X, whereby a relatively large amount of microwaves can be supplied from the outlet 50B.
[0037]
On the other hand, FIG. 7 shows a state in which the end 15X and the end 15Y are switched from the state shown in FIG. 6 by the rotation of the rotating shaft 15A in the direction of the arrow R (see FIG. 2). In this state, the end 15Y is located closer to the introduction port 50A than the end 15X. However, the distance from the end 15Y to the introduction port 50A in the state shown in FIG. 7 is longer than the distance from the end 15X to the introduction port 50A in the state shown in FIG. The guided microwave hardly travels to the introduction port 50A. Accordingly, in the state shown in FIG. 7, the microwave is less likely to be guided into the waveguide 50 than in the state shown in FIG. 6, and the amount of microwave supplied from the outlet 50B is also reduced.
[0038]
In the microwave oven 1 of the present embodiment and each modification thereof, control means for controlling the driving of the antenna motor 16 is provided. In the microwave oven 1, the magnetron 12 is stopped in a state where the rotation of the radiating antenna 15 is stopped at an appropriate position by utilizing the relationship between the position of the radiating antenna 15 and the diffusion mode of the microwave as described above. By oscillating the microwave, it is possible to select whether to supply the microwave on the food on the bottom plate 9 mainly from below or mainly from above. Of course, it is also possible to oscillate microwaves in the magnetron 12 while continuously rotating the radiation antenna 15 and supply the microwaves evenly into the heating chamber 10.
[0039]
In FIG. 8, the 3rd modification of the microwave oven 1 of this Embodiment is shown. The third modification is a diagram showing a state in which the reflecting plate as shown in FIGS. 5 and 6 is provided as the reflecting plate 52 in the microwave oven 1 as shown in FIG. The reflection plate 52 is made of a dielectric. 6 and FIG. 8, the positional relationship between the heating chamber 10 and the introduction port 50 </ b> A in the microwave oven 1 is different. Therefore, the reflection plate 52 is reflected so as to exist from the heating chamber 10 to the inside of the waveguide 50. The plate 51 has a different shape.
[0040]
[Second Embodiment]
FIG. 9 is a view of a longitudinal section of the microwave oven 1 according to the second embodiment of the present invention viewed from the right side. 9 corresponds to a cross-sectional view taken along the line IX-IX of the microwave oven 1 in FIG. Moreover, FIG. 10 is the figure which looked at the cross section of the exterior part 4 and the main body frame 5 of the microwave oven 1 of this Embodiment from upper direction.
[0041]
With reference to FIG. 9 and FIG. 10, in microwave oven 1 of the present embodiment, magnetron 12 is installed behind heating chamber 10, that is, on the opposite side of door 3 with respect to heating chamber 10. Further, below the bottom plate 9, two radiating antennas 15 and a rotating shaft 15 </ b> A are provided so as to be aligned in the left-right direction when viewed from the door 3. The waveguide 19 has a structure bifurcated from the magnetron 12 toward the heating chamber 10 so as to accommodate the two rotating shafts 15A.
[0042]
Also in the present embodiment, in the microwave traveling direction, the distance LE from the end of the waveguide 19 to the rotating shaft 15A is ¼ of the wavelength λ of the microwave.
[0043]
FIG. 11 is a longitudinal sectional view of the microwave oven 1 according to the present embodiment, and corresponds to a sectional view taken along the line II-II of the microwave oven 1 of FIG.
[0044]
Below the waveguide 19, antenna motors 16 attached to the two rotary shafts 15A are attached. The two antenna motors 16 are fitted in the rails 20 respectively. The rail 20 is provided so that the antenna motor 16 can be moved along a predetermined route in the vertical direction. Each antenna motor 16 is fixed to the cam 21. The cams 21 are each connected to a cam motor 22 via a connecting portion 22A.
[0045]
The connecting portion 22A is connected to the cam 21 at a position away from the center of the cam 21. From this, when the cam 21 is rotated by the rotation of the cam motor 22, the vertical position of the antenna motor 16 is changed. As a result, the penetration length LF, which is the length of the rotation shaft 15A that enters the waveguide 19, is changed. In addition, the length in this case is the length in the traveling direction of the microwave, and is the vertical direction in the vicinity of the rotating shaft 15A in FIG.
[0046]
FIG. 12 is a control block diagram of the microwave oven 1 according to the present embodiment.
Referring to FIG. 12, the microwave oven 1 includes a control unit 100 that controls the operation of the microwave oven 1 as a whole. The control unit 100 includes a magnetron 12, a heater 30 that heats food in the heating chamber 10 by generating heat, a cooling fan 31 for cooling members in the exterior part 4 such as the magnetron 12, an antenna motor 16, and a cam The operation of the motor 22, the sensor drive motor 70 that moves the infrared sensor 7 in order to change the infrared detection area of the infrared sensor 7, and the operation of the display unit 60 provided in the operation panel 6 are controlled. The control unit 100 includes information input by a key (operation unit) in the operation panel 6, a temperature sensor 32 that detects the temperature of a predetermined location in the exterior unit 4, and a detection output from the infrared sensor 7. Is entered.
[0047]
As shown in FIG. 12, in this embodiment, the two cam motors 22 are independently controlled. Thereby, the penetration length of the two rotating shafts 15A is controlled independently.
[0048]
When there are a plurality of rotating shafts 15A to which the radiating antenna 15 is attached in the microwave oven, the radiating antenna 15 attached to the rotating shaft 15A having a long penetration depth is a radiating antenna attached to the rotating shaft 15A having a short penetration depth. More than 15 microwaves are guided from the waveguide 19.
[0049]
13 and 14 are enlarged views of the vicinity of the rotating shaft 15A of the present embodiment. In FIG. 13, LF1 is the penetration length of one rotating shaft 15A in the microwave oven 1 of the present embodiment, and LF2 is the penetration length of the other rotating shaft 15A. In the present embodiment, as shown in FIG. 13, when “LF1 = LF2”, microwaves of the same degree are supplied to the heating chamber 10 through the two radiation antennas 15. In this case, it is considered that microwaves are evenly supplied into the heating chamber 10.
[0050]
On the other hand, as shown in FIG. 14, the penetration length of one rotating shaft 15A is “LF3”, but when the other rotating shaft 15A is not in the waveguide 19, the heating chamber 10 The microwave is mainly guided from the radiation antenna 15 attached to the one rotary shaft 15A, and the microwave is not guided from the radiation antenna 15 attached to the other rotary shaft 15A. In this case, the microwave oscillated by the magnetron 12 is supplied to the heating chamber 10 mainly through the radiation antenna 15 attached to one rotating shaft 15A. Will be supplied.
[0051]
That is, in the present embodiment, the control unit 100 appropriately controls the driving mode of the two cam motors 22 to supply the microwaves to the heating chamber 10 evenly or locally. The pattern for supplying the microwave into the heating chamber 10 can be changed intentionally.
[0052]
Further, when the microwave is supplied locally, the center of the heating chamber 10 to which the microwave is supplied is also controlled by controlling the position where the rotation of the cam 21 is stopped. Can do. Thereby, according to the arrangement | positioning of the foodstuff in the heating chamber 10, the pattern which supplies a microwave to the heating chamber 10 can be selected. The following examples can be given as specific examples when locally supplying the microwave.
[0053]
When two foods having different initial temperatures are placed in the heating chamber 10, the penetration length of the rotary shaft 15A connected to the radiation antenna 15 closer to the food having the lower initial temperature is set to the other rotation. It is longer than the penetration length of the shaft 15A. In the heating chamber 10, the position and temperature of the food are detected by the infrared sensor 7. When the temperature difference between the two foods in the heating chamber 10 disappears or becomes smaller than a predetermined value, the penetration lengths of the two rotary shafts 15A are made equal. Thereby, in the microwave oven 1, cooking which heats two foodstuffs from which initial temperature differs to comparable temperature can be performed as automatic cooking.
[0054]
[Third Embodiment]
FIG. 15 is a longitudinal sectional view of the microwave oven 1 according to the third embodiment of the present invention, and corresponds to a sectional view taken along the line II-II in FIG.
[0055]
The microwave oven 1 of the present embodiment is provided with a heater 30 in the vicinity of the radiation antenna 15. In the present embodiment, a region below the bottom plate 9 of the heating chamber 10 and provided with the radiation antenna 10 and the heater 30 is defined as a region 5W.
[0056]
In the microwave oven 1 of the present embodiment, a cam 88 is provided between the motor antenna 16 and the waveguide 19. The cam 88 is pivotally supported by the support member 16A in the same manner as the rotary shaft 15A. A switch 89 is provided near the cam 88. The control block diagram of the microwave oven 1 of the present embodiment is such that the detection output of the switch 89 is input to the control unit 100 in the control block diagram as shown in FIG.
[0057]
FIG. 16 is a diagram schematically showing the positional relationship among the motor antenna 16, the cam 88, and the switch 89 shown in FIG. When the antenna motor 16 is driven, the cam 88 rotates about the support member 16A in the direction of arrow P in FIG. The cam 88 is pivotally supported by the support member 16A at a position shifted from the center thereof. When the cam 88 rotates once, the switch 89 is turned on / off once. The rotational speed of the cam 88 depends on the driving force of the antenna motor 16. Therefore, in the present embodiment, the control unit 100 controls the timing at which the driving of the antenna motor 16 is stopped while referring to the time after the on / off of the switch 89 is switched, so that the radiation antenna can be accurately detected. The stop timing of 15 rotations can be controlled.
[0058]
The fact that the stop timing of the radiation antenna 15 is accurately controlled is particularly used in the present embodiment for accurately controlling the positional relationship of the radiation antenna 15 with respect to the heater 30.
[0059]
17 and 18 are diagrams showing the positional relationship between the heater 30 and the radiating antenna 15 in the present embodiment, and correspond to views seen from above. In the microwave oven 1, when the heater heating is performed by the heater 30 generating heat, the radiation antenna 15 is stopped as shown in FIG. Note that the state shown in FIG. 17 is a state in which the shortest distance LG between the heater 30 and the radiation antenna 15 is the longest when the radiation antenna 15 is fixed to the rotating shaft 15A.
[0060]
FIG. 18 shows a state where the shortest distance between the heater 30 and the radiation antenna 15 is shorter than that in FIG. That is, the shortest distance LH between the heater 30 and the radiation antenna 15 in FIG. 18 is shorter than the distance LG shown in FIG.
[0061]
19 and 20 are diagrams showing a modification of the present embodiment. In this embodiment, the heater 30 has an annular shape as shown in FIGS. 17 and 18, but in the modification shown in FIGS. 19 and 20, the heater 30 has two rod-like shapes. It is said to be original.
[0062]
FIG. 19 shows a state where the shortest distance LJ between the heater 30 and the radiation antenna 15 is the longest. In this modification, when the heater 30 is being heated by the heater 30, the radiation antenna 15 is stopped in the state shown in FIG. On the other hand, FIG. 20 shows a state where the heater 30 and the radiation antenna 15 are overlapped.
[0063]
The state shown in FIGS. 18 and 20 is a state that can be taken if the heater 30 is not heated by the heater 30.
[0064]
In the present embodiment, the distance between the heater 30 and the radiation antenna 15 is considered in the horizontal direction (the direction parallel to the spreading surface of the bottom plate 9), but the distance in the vertical direction can also be considered. That is, by providing the cam 21 and the cam motor 22 in the second embodiment, the height position of the radiation antenna 15 may be adjusted to change the distance from the heater 30.
[0065]
In addition, as shown in the second embodiment, the timing of stopping the rotation of the rotating body by controlling the drive timing of the motor using a cam and a switch as shown in the present embodiment is shown in the second embodiment. The present invention can be applied to accurately controlling the stop timing of the rotation of the cam 21 by controlling the drive timing of the cam motor 22. Thereby, the height of the rotating shaft 15A can be accurately controlled.
[0066]
Each embodiment and its modification disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims. Moreover, each embodiment may be implemented independently or in combination as much as possible.
[Brief description of the drawings]
FIG. 1 is a perspective view of a microwave oven according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the line II-II of the microwave oven of FIG.
FIG. 3 is an enlarged view of the vicinity of the lower portion of the heating chamber of FIG. 2;
4 is a diagram showing a first modification of the microwave oven of FIG. 1. FIG.
FIG. 5 is a diagram showing a second modification of the microwave oven of FIG. 1;
6 is an enlarged view of the vicinity of the lower part of the heating chamber of FIG.
7 is an enlarged view of the vicinity of the lower part of the heating chamber of FIG.
FIG. 8 is a diagram showing a third modification of the microwave oven of FIG.
FIG. 9 is a longitudinal sectional view of a microwave oven according to a second embodiment of the present invention.
FIG. 10 is a cross-sectional view of an exterior part and a main body frame of a microwave oven according to a second embodiment of the present invention.
FIG. 11 is a longitudinal sectional view of a microwave oven according to a second embodiment of the present invention.
FIG. 12 is a control block diagram of the microwave oven according to the second embodiment of this invention.
FIG. 13 is an enlarged view of the vicinity of the rotation axis according to the second embodiment of the present invention.
FIG. 14 is an enlarged view of the vicinity of a rotating shaft according to a second embodiment of the present invention.
FIG. 15 is a longitudinal sectional view of a microwave oven according to a third embodiment of the present invention.
16 is a diagram schematically showing a positional relationship between the motor antenna, the cam, and the switch shown in FIG.
FIG. 17 is a diagram illustrating a positional relationship between a heater and a radiation antenna in a microwave oven according to a third embodiment of the present invention.
FIG. 18 is a diagram illustrating a positional relationship between a heater and a radiation antenna in a microwave oven according to a third embodiment of the present invention.
FIG. 19 is a diagram showing a positional relationship between a heater and a radiating antenna in a microwave oven according to a modification of the third embodiment of the present invention.
FIG. 20 is a diagram illustrating a positional relationship between a heater and a radiation antenna in a microwave oven according to a modification of the third embodiment of the present invention.
[Explanation of symbols]
1 microwave oven, 3 doors, 6 operation panel, 7 infrared sensor, 10 heating chamber, 15 radiation antenna, 15A rotating shaft, 16 antenna motor, 19, 50 waveguide, 21 cam, 22 cam motor, 30 heater, 100 Control unit.

Claims (2)

A heating chamber containing food,
A door capable of opening and closing the front surface of the heating chamber;
A bottom plate disposed in the heating chamber for placing food contained in the heating chamber;
A magnetron that oscillates microwaves;
A waveguide disposed in the lower part of the heating chamber to guide the microwave oscillated by the magnetron to the heating chamber;
Two radiating antennas each having a rotation axis arranged from the waveguide to the inside of the heating chamber, and arranged below the bottom plate so as to be arranged in the left-right direction when viewed from the door;
An antenna motor attached to the rotating shaft and rotating the radiation antenna by rotating the rotating shaft;
A motor for changing the penetration length penetrating into the waveguide of each rotation axis;
A controller for controlling the operation of the magnetron, the antenna motor and the motor for changing the penetration length,
The motor for changing the intrusion length is configured so that the intrusion length of the other rotation shaft is longer than the intrusion length of one of the rotation shafts, so that a radiation antenna attached to the other rotation shaft The microwaves to be radiated are radiated more than the microwaves radiated from the radiating antenna attached to the one rotating shaft, and the penetration lengths of the rotating shafts are the same, so that the rotating shafts are attached to the rotating shafts Radiate microwaves radiated from the radiating antenna to the same extent,
The said control part changes the pattern which supplies a microwave in the said heating chamber by operating the motor for changing the said penetration | invasion length, The microwave oven characterized by the above-mentioned . The magnetron is disposed behind the heating chamber,
2. The microwave oven according to claim 1, wherein the waveguide has a structure bifurcated so as to accommodate the rotation axes .

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