JPH11193931A - Microwave oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heating efficiency, eliminate heating unevenness, and simplify the structure. SOLUTION: A rotary disc 9 provided on the bottom of a heating chamber 2 is provided with vertical bars continuously expanding in one direction and horizontal bars with a length of less than 1/2 of wavelength λ of microwave, and square openings. An optical sensor is provided so as to detect whether or not the rotary disc 9 is positioned at the reference position, and it can be stopped at a desired stopping position by controlling the energizing time of RT motor on the basis of its starting time. When 'heating rice' is selected, the rotary disc 9 turns by an angle A and stops there to be heated, and when 'heating sake' is selected, it turns by an angle B and stops there to be heated. The stopping position where the optimal electric boundary distribution can be obtained according to the kind of food is obtained experimentarily in advance, and its result is stored.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave oven having a rotating plate for supporting food at the bottom of a heating chamber, and heating the food by supplying microwaves into the heating chamber.

[0002]

In a microwave oven that performs microwave heating, there is a situation in which unevenness of electric field strength (heating energy) is generated in a heating chamber due to a standing wave of microwave. This leads to poor heating efficiency when heating relatively small foods (one bowl of rice, small side dishes, etc.) and relatively large foods (such as a plurality of shomai or pizza) Etc.), there is a problem that heating unevenness occurs.

[0003] In this case, it is common practice to rotate a food placing plate (turntable) on which the food is placed. However, although uneven heating in the circumferential direction can be suppressed, for example, an excitation port is provided on the side wall. In some cases, uneven heating in the radial direction remains, such as weak heating at the center portion of the food placement dish and strong heating at the outer peripheral portion. In addition, the heating unevenness in the vertical direction in a sake can or the like is not improved. Furthermore, when a small food is placed on the center of the food placing plate, the heating efficiency is not sufficiently high.

In order to improve the heating efficiency or the uneven heating, there have heretofore been considered several configurations as described below. However, each of them has some disadvantages, and has not been so effective.

That is, as a first conventional example, in a waveguide,
A movable element for impedance adjustment is provided, and an oven impedance is adjusted to a maximum efficiency condition of a magnetron in accordance with a state in an oven (heating chamber) to realize high efficiency. However, in this case, the conductor for impedance adjustment provided in the waveguide has a drawback that spark generation is a factor. If the spark generation is to be suppressed, the impedance adjustment effect is reduced.

As a second conventional example, it has been considered that a movable excitation port is provided at the bottom of the heating chamber, and the movable excitation port is moved to a position directly below the food to perform efficient heating. However, in this case, the drive mechanism of the movable excitation port becomes complicated, and it is difficult to install the movable excitation port, resulting in poor practicality. Further, as a third conventional example, it has been considered to adopt a configuration in which the food placing plate is moved up and down with rotation, and the heating distribution is improved by the up and down movement. However,
In this case, it is necessary to add a configuration for driving the food placing plate up and down, and there has been a problem that the configuration is complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a microwave oven which can improve heating efficiency and heat unevenness and can be completed with a simple structure. To be.

[0008]

SUMMARY OF THE INVENTION In a microwave oven,
Food is placed directly on the rotating plate made of a conductive material provided at the bottom of the heating chamber or via a food placing plate (turntable) made of a radio wave transmitting material. The present inventor has focused on the function of a rotating plate made of a conductive material as a radio wave reflector, and by configuring the rotating plate to have a non-homogeneous shape in the rotation direction, the rotation caused the standing wave to disturb in a random manner. In addition to this, the present inventors have found that a change in the position (rotation angle) of the rotating plate allows a different electric field distribution and thus a heating distribution to be obtained in the heating chamber, thereby achieving the present invention.

That is, the microwave oven of the present invention comprises a heating chamber,
Microwave supply means for supplying microwaves into the heating chamber, and a rotating plate configured to be non-homogeneous in the rotation direction from a conductive material and provided at the bottom of the heating chamber to support food,
It is characterized in that it comprises a drive mechanism for rotating and driving the rotary plate, and control means for controlling a stop position of the rotary plate so as to perform heating according to food.
Invention).

[0010] Here, for example, for food such as sake cans, a heating distribution that does not cause uneven heating in the vertical direction by reducing the heating at the upper part and increasing the heating at the lower part is suitable, and a relatively small food such as one cup of rice About, the heating distribution that the central part of the heating chamber is heated strongly is suitable, and for relatively large foods that spread in the plane direction such as multiple
There is an appropriate predetermined heating distribution or a combination of a plurality of predetermined heating distributions depending on the type and size of each food, such as a uniform heating distribution in the plane direction.

According to the above configuration, when the stop position of the rotating plate fluctuates as described above, a different heating distribution can be obtained in the heating chamber. Is controlled so as to perform heating in accordance with. Therefore, it is possible to perform efficient heating according to the food, and to perform cooking with a good finish without heating unevenness. In addition, it can be realized only by controlling the rotating plate, and the configuration can be simplified.

In this case, as a mode of controlling the stop position of the rotary plate by the control means, the rotary plate can be stopped at a predetermined stop position according to the food type input by the user or automatically determined ( The invention of claim 2). Further, a rotary heating mode in which the food is heated while rotating the rotary plate and a stop heating mode in which the rotary plate is stopped at a predetermined stop position to heat the food can be selected according to the food type (claim). Item 3 invention). Further, according to the type of food, a combined heating mode in which heating of the food in a state where the rotating plate is stopped at a predetermined stop position and heating of the food while rotating the rotating plate is performed is performed. (The invention of claim 4).

[0013] According to these, the pattern of the heating distribution is increased, and a variety of heating modes can be selected. Therefore, the range of selection in performing the heating according to the food type is increased. Thus, it is possible to further enhance the effects of improving the heating efficiency and the uneven heating.

[0014] For heavy foods and the like, if only heating in the stop heating mode is performed for a long time, uneven heating may occur. Therefore, the control means stops the rotating plate at a predetermined stop position corresponding to the type of food until the predetermined heating time, heats the food, and after the predetermined heating time, rotates the rotating plate while rotating the food. Can be heated (the invention of claim 5),
Thus, uneven heating in the case of performing heating for a long time can be reduced.

Further, stop position detecting means for detecting the stop position of the rotating plate can be provided, and the control means can be configured to control the stop position of the rotating plate based on the detection result of the stop position detecting means. (The invention of claim 6). Thus, even if a plurality of stop positions for stopping the rotating plate are set, it is possible to reliably stop the rotating plate at the predetermined stop position.

At this time, the stop position detecting means is configured to detect the reference position of the rotary plate, and the control means is configured to set the rotary plate to a predetermined stop position according to the rotational driving time from the reference position of the rotary plate. The structure for stopping the rotation plate can be adopted (the invention of claim 7), whereby the structure for detecting the stop position of the rotary plate and controlling the stop position can be simplified. Further, in this case, the stop position detecting means can be configured using an optical sensor (the invention of claim 8) or using a magnetic sensor (the invention of claim 9). With this configuration, the reference position can be detected.

Alternatively, the stop position detecting means may be configured to indirectly detect a stop position of the rotary plate by detecting an angle of a rotary shaft connected to the rotary plate at a predetermined rotational direction and rotating the rotary plate. (Invention of claim 10). Accordingly, a mechanism for detecting the stop position of the rotating plate can be provided outside the heating chamber.

Further, even if the heating distribution in the heating chamber can be made suitable for food as described above, particularly for small foods, if the food is not located at an appropriate position, the effect of the heating distribution can be obtained. Cannot be obtained sufficiently.
Therefore, if a mark indicating a position suitable for placing food is displayed on the rotating plate or the food placing plate set on the rotating plate (the invention according to claim 11), the user can control the heating. The food can be placed at a position where the effect of the distribution can be sufficiently obtained. At this time,
If the mark is displayed by irradiating a spotlight (the invention of claim 12), the display can be displayed in an easily recognizable manner.

By varying the stop position of the rotating plate as described above, the structure of the rotating plate becomes important in order to obtain a different electric field distribution and thus a heating distribution in the heating chamber. By doing so, it is possible to increase the change in the electric field distribution due to the fluctuation of the stop position of the rotating plate, that is, to increase the pattern of the heating distribution. Needless to say, it is necessary to perform the original function as a rotating plate for supporting food directly or via a food placing plate.

Therefore, the rotating plate is formed in a lattice shape having a vertical bar and a horizontal bar orthogonal thereto in the surrounding frame, and the vertical bar extends continuously in one direction. The book can be configured so as to be divided so that the length of the book is less than の of the microwave wavelength (the invention of claim 13).

According to this, when the microwave is applied to the rotating plate made of a conductor, the wall current flows along the lattice portion, and the current flows in one direction in which the vertical bar extends. The electric field distribution changes depending on the flowing direction, that is, the stop position of the rotating plate. Further, it becomes difficult for the current to flow in the direction of the horizontal bar, which is less than half the microwave wavelength. Therefore, a change in the electric field distribution due to a change in the stop position of the rotating plate can be increased.

Further, the rotating plate is formed in a grid shape having a vertical bar and a horizontal bar orthogonal thereto in a surrounding frame, and a central opening having a length of at least ４ of the microwave wavelength in both the vertical and horizontal directions at the center thereof. A portion may be provided (the invention of claim 14). According to this, since the microwave is easily transmitted through the central portion of the rotating plate by the central opening, the transmittance of the microwave reflected on the bottom surface of the heating chamber upward in the central portion of the rotating plate is large. As a result, the food placed at the center of the rotating plate can be heated more strongly.

In this case, an excitation port for supplying microwaves into the heating chamber is provided at a position on the side wall of the heating chamber at a height of not more than の of the microwave wavelength from the rotating plate. Accordingly, the microwave supplied from the excitation port into the heating chamber can easily enter between the rotary plate and the bottom surface of the heating chamber.
At this time, if the wall connected to the lower end of the excitation port at the exit of the waveguide that guides the microwave into the heating chamber has a shape that is inclined downward toward the excitation port (the invention of claim 16), the excitation port The microwave supplied into the heating chamber from below can be guided downward, so that it can be more easily entered between the rotating plate and the bottom surface of the heating chamber.

Further, the bottom portion of the heating chamber may be formed in a shape corresponding to the central portion of the rotary plate, which is raised in a mountain shape (claim 17). According to this, the microwaves that have entered the bottom of the heating chamber are guided upward through the central portion of the rotating plate by the raised shape, thereby further promoting the transmission of the microwaves at the central portion of the rotating plate. can do.

The opening formed by the grid of the rotating plate has a rectangular shape in the portion near the outer periphery of the rotating plate in which the vertical direction is at least 以上 of the microwave wavelength and the horizontal direction is less than ４ of the microwave wavelength. May be formed (the invention of claim 18). According to this, when the longitudinal direction of the opening intersects with the traveling direction of the microwave, the microwave is easily transmitted, and the microwave is transmitted when the traveling direction of the microwave coincides with the longitudinal direction of the opening. Waves are less likely to penetrate. As a result, the change in the electric field distribution due to the change in the stop position of the rotating plate can be increased.

In this case, the vertical bars of the grid of the rotating plate can be configured to be continuous in one direction from the end to the end in the peripheral frame (the invention of claim 19). The irradiation causes a wall current to flow along the vertical bars of the lattice, and the electric field distribution can be changed depending on the stop position of the rotating plate.

Here, the shape of the rotating plate is not limited to the lattice shape having the vertical bars and the horizontal bars as described above. For example, the rotary plate may have a radial rib inside a circular peripheral frame.
When rotated by 0 / n degrees (n is an integer of 2 or more), it can be formed into a rotationally symmetrical shape that becomes the same shape as the original shape (the invention of claim 20). This makes it possible to change the electric field distribution.

In this case, if the rotating plate has a rotationally symmetric shape, the same electric field distribution appears n times every 360 / n degrees during one rotation cycle. Then, after heating a food by stopping the rotating plate at a predetermined stop position, it is possible to repeatedly rotate and stop the rotating plate 360 / n degrees from the stop position (claim 2).
1 invention).

According to this, while always obtaining an electric field distribution suitable for the food, it is possible to heat the food while changing the direction of the food with respect to the excitation port. People no longer feel uncomfortable. Further, at this time, if the one stop time at each stop position is all constant (the invention of claim 22), it is possible to prevent uneven heating in the direction of the food.

For such a rotationally symmetric rotating plate, n reference positions for generating the same detection signal are equally set in the circumferential direction of the rotating plate as reference positions for detecting the position of the rotating plate. (Invention of claim 23). According to this, it is possible to reduce the time required to detect the reference position of the rotating plate from an arbitrary initial position of the rotating plate, and eventually to stop the rotating plate at the predetermined position.

Alternatively, a plurality of reference positions for generating mutually different detection signals may be provided as reference positions for detecting the position of the rotating plate (the invention of claim 24). This can also reduce the time required to detect any reference position of the rotating plate and stop at the predetermined position. At this time, the two reference positions may be provided so as to generate different numbers of detection signals corresponding to the 180-degree symmetric positions of the rotating plate (the invention of claim 25). According to the simple configuration, the rotary plate 180
The reference position can be detected by rotation within a degree.

Further, the control means is configured to execute at least one operation of rotating the rotary plate by 180 degrees to stop the food while heating the food by stopping the rotary plate at a predetermined stop position. It may be configured (the invention of claim 26).
According to this, the food is irradiated with microwaves from one side in a strong direction, and even if the opposite side of the food is shaded, the food is turned 180 degrees during heating. In addition, microwave irradiation on both surfaces can be equalized.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the drawings. (1) First Embodiment First, a first embodiment of the present invention (Claims 1, 2, 3, 4, and 5)
6, 7, 8, and 13) will be described with reference to FIGS.

FIGS. 3 and 4 schematically show the inside of the heating chamber of the microwave oven according to this embodiment. The microwave oven is configured by arranging an oven box 1 having a rectangular box shape with an open front in an outer box (not shown). The inside of the oven box 1 is a heating chamber 2. Although not shown,
A door for opening and closing the heating chamber 2 is provided on the front surface of the outer box, and located on the right side thereof, the user can select a food type (cooking menu), set a cooking time, and start cooking. An operation panel 3 (shown only in FIG. 2) for giving instructions and the like is provided. As shown in FIG. 2, an operation signal of the operation panel 3 is input to a control circuit 4 including a microcomputer or the like.

Although not shown in detail, a machine room is provided in the outer box at the right side of the oven chamber 1, and a micro room is provided in the machine room as shown in FIG. A magnetron 5 that oscillates waves, its driving circuit, a cooling fan device 6, the control circuit 4, and the like are provided. Further, in the present embodiment, a heater 7 (shown only in FIG. 2) for heating the cooked material with a heater is provided on the ceiling of the heating chamber 2.

Microwaves oscillated from the magnetron 5 pass through a waveguide (not shown), and in this case, an excitation port 8 (FIG. 3, FIG. 4) formed in the right side wall of the oven chamber 1.
) Is supplied into the heating chamber 2.
Therefore, the microwave supply means is constituted by the magnetron 5 and the waveguide. Further, as shown in FIG. 2, the magnetron 5, the cooling fan device 6, and the heater 7 are also controlled by the control circuit 4.

FIG. 5 shows the bottom of the heating chamber 2.
As shown in FIG. 2, a rotating plate 9 is formed by enamelling the surface of a conductive material such as a steel plate, and has an overall outer shape of a circular flat plate. The shape of the rotating plate 9 will be described later. The center of the rotary plate 9 is connected to a rotary shaft 10 provided through the bottom surface of the heating chamber 2 (oven storage 1), and the rotary shaft 10 is provided on the outer bottom surface side of the heating chamber 2. It is driven to rotate by an RT motor 11 (see FIG. 2). Therefore, a driving mechanism is constituted by the RT motor 11, the rotating shaft 10, and the like. The RT motor 11 is also controlled by the control circuit 4. The rotating plate 9 is rotated at a constant speed in one direction (for example, clockwise as viewed from above) by driving the RT motor 11.

As shown in FIGS. 3, 4 and 6 with a part cut away, a turntable 9 made of heat-resistant glass or ceramic is provided on the upper surface of the rotary plate 9.
Are set so as to be removable, and the food F is placed on the food placing plate 12. Therefore, the rotating plate 9 supports the food F via the food placing plate 6. The excitation port 7 is provided at a position slightly higher than the rotating plate 9. Further, for example, when performing heater cooking such as toast, the food placing plate 12 is removed from the rotating plate 9 and the rotating plate 9 is used as a grill.

Specifically, as shown in FIG. 5, the rotary plate 9 integrally includes a plurality of vertical bars 9b and a plurality of horizontal bars 9c orthogonal to the inside of an annular peripheral frame 9a. It is configured in a lattice. A boss 9d connected to the rotating shaft 10 is provided at the center. At this time, most of the vertical bars 9b extend continuously in one direction (the front-rear direction in FIG. 5), and are provided at equal pitches in the left-right direction in FIG. On the other hand, the horizontal bar 9c is provided in such a form that most of the horizontal bar 9c is divided so as to have a length of less than １ ／ of the wavelength λ of the microwave (about 122 mm).

In this case, from the vertical bar 9b and the horizontal bar 9c, several rectangular openings 9e long in the front-rear direction in FIG.
“e” is provided so as to be shifted in the longitudinal direction by a half pitch at a time in the left-right direction in the figure. Incidentally, the vertical dimension a of the opening 9e is λ / 2 or more, for example, 64 mm, and the horizontal dimension b is less than λ / 4, for example, 30 mm. Thus, the rotating plate 9 has a non-homogeneous shape in the rotating direction, and has a point-symmetrical shape with respect to the center point (the same shape even when rotated by 180 degrees) in the present embodiment.

As shown in FIG. 6, a light reflecting portion 13 is provided at a predetermined position of the peripheral frame 9a of the rotating plate 9. On the other hand, the rotating plate 9 is provided on the side wall of the heating chamber 2.
As a stop position detecting means for detecting the reference position, a reflection type optical sensor 14 having a light projecting portion 14a and a light receiving portion 14b arranged side by side is provided. In this embodiment, for example, the vertical bar 9
The position where the direction in which b extends corresponds to the front-back direction of the heating chamber 2 is the reference position of the rotating plate 9, and
Is provided at a position where when the stop position of the rotating plate 9 reaches the reference position, the light emitted from the light projecting portion 14a is reflected by the light reflecting portion 13 and received by the light receiving portion 14b. . As shown in FIG. 2, the detection signal of the optical sensor 14 is input to the control circuit 4.

The control circuit 4 controls the magnetron 5, the RT motor 11 and the like based on an input signal from the operation panel 3 to execute heating cooking.
As will be described later in detail in the description of the operation, at the time of range cooking, the rotation of the rotating plate 9 is controlled so that heating according to the type of food F (cooking menu) is performed. . Therefore, the control circuit 4 functions as control means.

At this time, in this embodiment, when a predetermined food type ("warm rice" and "liquor can") is selected, the rotating plate 9 is stopped at a predetermined stop position (rotation angle). A stop heating mode for performing heating is executed. At this time, a plurality of stop positions at which the rotating plate 9 stops are set according to the food type. More specifically, when the food type is “warm rice”, as shown in FIG.
When the food type is “Sake no Kan”, the rotating plate 9 is stopped at a position advanced by an angle B from the reference position, as shown in FIG. 4B. I have.

To stop the rotating plate 9 at an arbitrary position, the control circuit 4 sets the rotating plate 9 at the angle A.
And the energizing time (T (A) and T (B)) to the RT motor 11 required to rotate the motor by the angle B are stored in advance. First, the rotary plate 9 is continuously rotated, and the optical sensor 14 detects the reference position. Is detected, the RT motor 11 is driven to rotate for the current supply time and stopped.

In this embodiment, when the food type is “thaw-cooking”, the rotating plate 9 is moved from the reference position to the angle C (the energizing time T (C)
), The heating is performed for a fixed period of time, and for the remaining heating time, a combined heating mode in which heating is performed while the rotating plate 9 is continuously rotated is executed. Furthermore, when a food type other than the above-mentioned predetermined food type is selected, a rotary heating mode in which heating is performed while the rotating plate 9 is continuously rotated is executed.

Next, the operation of the above configuration will be described with reference to FIG. When a microwave having a predetermined wavelength is supplied from the excitation port 7 into the heating chamber 2, a predetermined standing wave is generated depending on the size (the position of the wall) of the heating chamber 2, and heating is caused by the standing wave. Strength of electric field in chamber 2 (large or small heating energy)
Unevenness occurs. However, at the bottom of the heating chamber 2, there is provided a rotating plate 9 which is made of a conductive material and has a non-homogeneous shape in the rotating direction. The state of reflection or transmission of the laser beam fluctuates, and a different electric field distribution and thus a heating distribution in the heating chamber 2 can be obtained.

In particular, the rotating plate 9 of this embodiment has a vertical bar 9b extending continuously in one direction and a horizontal bar 9c having a length of less than の of the wavelength λ of the microwave. Is rectified in one direction in which the vertical bar 9b extends,
The electric field distribution is changed by the flowing direction, that is, the stop position of the rotating plate. Moreover, since the opening 9e has a rectangular shape, when the longitudinal direction of the opening 9e intersects with the traveling direction of the microwave, the microwave is easily transmitted, and the traveling direction of the microwave and the longitudinal direction of the opening 9e. When the directions coincide with each other, microwaves are hardly transmitted.

As a result, a characteristic electric field distribution can be obtained depending on the stop position of the rotating plate 9, and a change in the electric field distribution caused by a change in the stop position of the rotating plate 9 is sufficiently large, that is, a pattern having a large heating distribution pattern. It becomes. Therefore, by continuously rotating the rotary plate 9, the heating chamber 2
The electric field distribution inside changes greatly with time,
Since the food itself is also rotating, the food F can be uniformly heated without uneven heating.

However, such a uniform electric field distribution is suitable for heating relatively large foods (such as a plurality of shomai or pizza) spread in a plane direction. In such a case, uneven heating in the vertical direction occurs in which the upper portion is excessively heated by convection. In addition, from the viewpoint of the heating efficiency, for example, in the case of warming rice, a problem such as poor heating efficiency occurs. That is, depending on the type of food, it may be more appropriate to stop the rotating plate 9 at a predetermined stop position and heat the same with a predetermined electric field distribution.

That is, as shown in FIG.
Is stopped at a stop position advanced by an angle A from the reference position, an electric field distribution with the highest heating efficiency can be obtained for "warming rice", and as shown in FIG.
Is stopped at a stop position advanced by an angle B different from the angle A from the reference position, so that the upper and lower heating unevenness does not occur when performing the sake canning (the lower portion is heated strongly and the upper and lower Can be uniformly heated in the direction)
An electric field distribution is obtained.

In the case of “thawing cooking”, the rotating plate 9
Is stopped at a stop position advanced by an angle C from the reference position, and heating is performed for a fixed time, and thereafter, the rotating plate 9 (food F)
By continuously rotating the, the heating can be performed with good heating efficiency and without heating unevenness. The stop positions (angles A, B, and C) of the rotating plate 9 at which the optimum electric field distribution according to the type of food is obtained are, for example, experimentally obtained in advance. Note that these angles A, B, and C correspond to the rotation of the food F on the rotating plate 9 (the food placing plate 1).
It is considered to be most effective when placed at the center of 2).

Therefore, in the present embodiment, as shown in the flowchart of FIG. 1, the control of the rotating plate 9 by the control circuit 4 is performed. That is, when the user operates the operation panel 3 to select a cooking menu (type of food F) and turns on the start key (step S1), the magnetron 5 is driven to start the heating cooking (step S2). At the same time, the rotating plate 9 is controlled in step S3 and subsequent steps.

At this time, first, it is determined whether or not the cooking menu selected by the user is a predetermined cooking menu (in this case, one of “warm rice”, “sake kan”, and “thawing cooking”) ( Step S3). When the menu is a cooking menu other than the predetermined cooking menu (for example, “warm-up”) (No), the rotating plate 9 is continuously rotated (step S4), and the food F is rotated in the heating chamber 2. The heating cooking in the rotary heating mode in which heating is performed while the heating is being performed is executed.

On the other hand, if the menu is a predetermined cooking menu (Yes in step S3), the rotation of the rotating plate 9 is started (step S5), and the operation of detecting the reference position by the optical sensor 14 is executed. Is performed (step S6). When the reference position of the rotating plate 9 is detected (Step S)
(Yes at 6), after that, different control is performed for each cooking menu (step S7). However, when the cooking menu is "warm rice", the rotating plate 9 is moved from the reference position detection time to the time T (A). And stop at a position advanced by an angle A from the reference position as shown in FIG. 4A (step S8).

Then, when the cooking menu is "Sake no Kan", the rotating plate 9 is rotated by the time T (B) from the point of detection of the reference position, and as shown in FIG. (Step S9). As described above, when the cooking menu is “warm rice” or “liquor can”, the stop heating mode in which the rotating plate 9 is stopped at a predetermined angle A or B corresponding to the type of the food F to perform heating. Is executed. When the predetermined cooking time has elapsed, the cooking is terminated (step S10).

When the cooking menu is “thaw cooking”, first, the rotating plate 9 is moved for a time T from the point of detection of the reference position.
(C) to stop at a position advanced by an angle C from the reference position (step S11), and perform heating for a predetermined time in this state (step S12), and then rotate the rotating plate 9 continuously (step S12). Step S13) is switched to heating for the remaining time (step S14), whereby the combined heating mode is executed.

As described above, according to the present embodiment, the rotating plate 9 made of a conductive material is formed in a non-homogeneous shape in the rotation direction, so that the stop position varies, so that the rotating plate 9 varies in the heating chamber 2. Focusing on obtaining an electric field distribution, the stop position of the rotating plate 9 is configured to be controlled so that heating according to the cooking menu (the type of the food F) is performed. As a result, it is possible to perform efficient heating according to the type of the food F, and to perform heating and cooking with a good finish without uneven heating. Since the improvement of the unevenness can be realized only by controlling the stop position of the rotating plate 9, an excellent practical effect that a simple configuration can be achieved can be obtained.

In this case, particularly in this embodiment, the stop heating mode for stopping the rotating plate 9 is executed at different angles for the two kinds of foods, and the combined heating mode is adopted in another cooking menu. As a result, the number of heating distribution patterns increases in addition to the rotation heating mode, and a variety of heating modes can be selected. It is possible to further enhance the effects of improving the efficiency and the uneven heating.

In this embodiment, the optical sensor 14 is configured to detect the reference position of the rotating plate 9 and
Since the stop position of the rotating plate 9 is controlled by the rotation driving time of the rotating plate 9 from the reference position, even if a plurality of stop positions for stopping the rotating plate 9 are set, the rotating plate 9 is kept at a predetermined position. It is possible to reliably stop at the stop position, and it is possible to obtain an advantage that the structure for detecting the stop position of the rotating plate 9 and controlling the stop position can be simplified.

Further, in this embodiment, the grating inside the rotating plate 9 is divided into a vertical bar 9b extending continuously in one direction so as to have a length of less than half the wavelength λ of the microwave. And a plurality of rectangular openings 9e are formed, so that the change in the electric field distribution accompanying the fluctuation of the stop position of the rotating plate 9 can be made sufficiently large. You can do it.

In the above embodiment, the stop heating mode or the composite heating mode is executed for three types of cooking menus, "warm rice", "shukan", and "thaw cooking". For example, the stop mode may be executed only when the cooking menu is “Sake no Kan”, and conversely, for more various cooking menus,
Different stop heating modes such as individually stop positions may be executed. In this case, the composite heating mode may be provided as needed. In addition, various modifications can be made to the configuration of the rotating plate 9 (the shape and interval of the grating, the size of the opening, and the like) as long as the shape is non-uniform in the rotation direction.

(2) Second to Seventh Embodiments Next, second to seventh embodiments of the present invention will be described below in order with reference to FIGS. The embodiment described below can be said to be a so-called modified example of the first embodiment, and the basic parts are common to the first embodiment. Therefore, the same parts as those in the first embodiment are denoted by the same reference numerals, detailed description and new illustration are omitted, and only the characteristic points will be described below.

FIG. 7 shows a second embodiment of the present invention.
Is a flowchart showing a procedure for controlling the rotation of the rotating plate 9. This embodiment differs from the first embodiment in that the type (cooking menu) of the food F is automatically determined. That is, when the start switch is turned on by the user, heating is started (step S21), and then the cooking menu is automatically determined (step S22), and thereafter, the same as in the first embodiment described above. Control is performed (steps S3 to S14).

In this case, although the detailed description is omitted, the automatic determination of the cooking menu is performed by using a gas sensor (alcohol sensor, steam sensor), a weight sensor, a shape sensor, and the like. The time required for the automatic determination is as short as 10 seconds or less. According to the second embodiment, the same operations and effects as those of the first embodiment can be obtained.

FIG. 8 shows a third embodiment of the present invention.
). In this embodiment, the rotating plate 9
As the stop position detecting means for detecting the reference position, the light emitting part 21a and the light receiving part 2 are provided at the corner on the back side of the heating chamber 2 in place of the reflection type optical sensor 14 in the first embodiment.
The transmission type optical sensor 21 in which the optical sensor 1b is disposed to face is used. At this time, a projection 22 projecting in the outer peripheral direction is provided at a predetermined position on the outer peripheral edge of the rotating plate 9. In such a configuration, the reference position of the rotating plate 9 is set at a position where the projection 22 crosses the optical axis between the light projecting unit 21a and the light receiving unit 21b.
Thus, the reference position of the rotating plate 9 can be detected.

FIG. 9 shows a fourth embodiment of the present invention.
). In this embodiment, the rotating plate 9
A magnet 23 is provided at a predetermined position on the outer peripheral edge of the rotating chamber 9, and a magnetic sensor 24 such as a Hall element as a stop position detecting means for detecting a reference position of the rotating plate 9 is provided on the wall of the heating chamber 2.
Is provided. Also in this configuration, the reference position of the rotating plate 9 is detected by the detection of the magnet 23 by the magnetic sensor 24.

FIG. 10 shows a fifth embodiment (corresponding to claim 10) of the present invention. Here, the rotating plate 9
In the present embodiment, the upper part 25a of the rotating shaft 25 is formed in a rectangular shape in cross section (upper surface) and the rotating plate 9 is connected to the upper end of the rotating shaft 25 driven by the RT motor 11. It is configured to be connected to the rotation shaft 25 at a predetermined rotation direction position. And heating room 2
On the lower side of the bottom plate of (oven storage 1), the rotating shaft 25
Is provided with a cam 26 projecting in the outer peripheral direction, and a switch 27 operated by the cam 26 is provided to constitute a stop position detecting means.

In such a configuration, the position where the switch 27 is operated by the cam 26 is detected as the reference position of the rotating plate 9, and the stop position of the rotating plate 9 is similarly controlled. Thus, a mechanism for detecting the stop position of the rotating plate 9 can be provided outside the heating chamber 2, and advantages in terms of assemblability, heat resistance, and the like can be obtained. The shape of the upper end of the rotating shaft 25 can be various shapes such as an elliptical shape, a so-called D-cut, and the like, in addition to a rectangular cross-section.

The method for stopping the rotating plate 9 at a predetermined stop position is not limited to the method of detecting the reference position and performing time control. For example, if there is one stop position, the sensor may obtain a detection signal when the rotating plate 9 is positioned at the stop position, and the rotation may be stopped immediately. If the rotating plate 9 is point-symmetric, two detection positions can be provided every 180 degrees. When there are a plurality of stop positions, a plurality of switches (sensors) may be provided for each position. Further, even with one switch, it is possible to stop at a plurality of stop positions depending on the number of times a signal is obtained. Further, the configuration may be such that the rotation angle of the rotary plate 9 (rotary shafts 10, 25) is directly detected by an encoder or the like.

If the rotation direction of the motor for driving the rotating plate 9 cannot be defined in one direction, the reference position is set at an intermediate position between the stop position and a point symmetrical position. If the plate 9 is rotated by 90 degrees from the time of detection of the reference position, it can be stopped at a predetermined stop position in any direction.

FIG. 11 shows a sixth embodiment (corresponding to claim 11) of the present invention. Here, as described above, even if the heating distribution in the heating chamber 2 can be made optimal according to the cooking menu, especially for the small food F, the food F is placed on the food placing plate 12. If it is not placed at an appropriate position, the effect of the heating distribution cannot be sufficiently obtained. Therefore, in the present embodiment, marks 28 and 29 indicating positions suitable for placing the food F are displayed on the upper surface of the food placing plate 12 set on the rotating plate 9.

In this case, the marks 28 and 29 are composed of picture patterns representing "rice" and "sake", respectively. Also,
At this time, the food placing tray 12 is of course set at a predetermined rotation direction position with respect to the rotating plate 9. According to this, the user can place the food F at a position where the effect due to the heating distribution can be sufficiently obtained.

FIG. 12 shows a seventh embodiment (corresponding to claim 12) of the present invention. In this embodiment, the marks 28 and 29 made of the picture pattern in the sixth embodiment are used.
In place of the spotlight 30 on the upper surface of the food
Irradiates the display of a position suitable for placing the food F. According to this configuration, it is possible to perform a display that is easy to understand and conspicuous.

(3) Eighth Embodiment Next, an eighth embodiment of the present invention will be described.
6, 17, 18, and 19) will be described with reference to FIGS. First, FIG. 13 shows a configuration of the rotating plate 31 in the present embodiment. This rotating plate 31
Is also formed by applying an enamel treatment to the surface of a conductive material such as a steel plate, for example, and has a circular flat dish shape and a non-homogeneous shape (point-symmetrical shape with respect to the center point) in the rotation direction.

More specifically, the rotating plate 31 is formed in a lattice shape integrally having a plurality of vertical bars 31b and a plurality of horizontal bars 31c orthogonal thereto in an annular peripheral frame 31a. . In addition, a rotating shaft 10 (FIG.
Boss 31d is provided. At this time, the vertical bars 31b extend continuously from one end to the other end in the peripheral frame 31a in one direction (the front-rear direction in the drawing) and are provided at substantially equal pitches in the left-right direction in the drawing. On the other hand, most of the horizontal bar 31c has a microwave wavelength λ.
(Approximately 122 mm).

At this time, in the present embodiment, a plurality of substantially square central openings 32 (four so as to surround the boss 31d) are formed in the center of the rotating plate 31 from the vertical bar 31b and the horizontal bar 31c. And two before and after it, a total of six). The central opening 32 has a vertical and horizontal dimension c of 共 に or more of the wavelength λ of the microwave, for example, 31 mm. Further, in the portion near the outer periphery of the rotating plate 31 (the left and right portions in the drawing of the portion where the central opening 32 is formed), several rectangular openings 31e long in the front-rear direction in the drawing are formed with substantially the same dimensions. As in the first embodiment, the opening 31e has a vertical dimension a of λ / 2 or more, for example, 64 mm, and a horizontal dimension b of less than λ / 4, for example, 30 mm.

Then, as shown in FIGS. 14 and 15,
An excitation port 34 for supplying a microwave oscillated from the magnetron 5 into the heating chamber 2 through the waveguide 33 (see FIG. 15) is provided on the right side wall of the heating chamber 2. The excitation port 34 is provided so that the height d from the rotating plate 31 is equal to or less than １ ／ of the wavelength λ of the microwave. Further, as shown in FIG. 15, a wall 33a connected to the lower end of the excitation port 34 at the exit of the waveguide 33 is formed.
Are inclined downward toward the excitation port 34. Further, in the present embodiment, as shown in FIG. 15, on the bottom surface of the heating chamber 2, a raised portion 35 in which a portion corresponding to the center of the rotating plate 31 is raised in a mountain shape (gently conical shape). Is formed.

In this configuration, since the central opening 32 is formed in the center of the rotating plate 31, the central opening 32 facilitates the transmission of microwaves through the center of the rotating plate 31. For this reason, the transmittance of the microwave reflected from the bottom surface of the heating chamber 2 upward at the center of the rotating plate 31 increases, and the rotating plate 31 (the food tray 12).
Can be heated more strongly.

In this case, since the excitation port 34 is provided at a relatively low position, the microwave supplied from the excitation port 34 into the heating chamber 2 enters between the rotating plate 31 and the bottom surface of the heating chamber 2. Since the wall portion 33a connected to the lower end of the excitation port 34 of the waveguide 33 is formed to be inclined downward, the microwave supplied into the heating chamber 2 is guided downward. , And it becomes easier to enter between the rotating plate 31 and the bottom surface of the heating chamber 2. Furthermore, since the raised portion 35 is provided on the bottom surface of the heating chamber 2, the microwave that has entered the bottom portion of the heating chamber 2 is guided upward by the raised portion 35 through the central portion of the rotating plate 31. Thus, the transmission of microwaves at the center of the rotating plate 31 can be further promoted.

Further, similarly to the rotating plate 9 of the first embodiment, the rotating plate 31 includes a vertical rod 31b extending continuously in one direction.
And a horizontal bar 31 having a length of less than half the wavelength λ of the microwave.
c, and has a rectangular opening 31e, so that a characteristic electric field distribution is obtained depending on the stop position of the rotating plate 31, and the change in the electric field distribution accompanying the fluctuation of the stopping position of the rotating plate 31 is sufficiently large. It can be.

(4) Ninth Embodiment FIGS. 16 and 17 show a ninth embodiment of the present invention.
0, 21, 22, 24, and 25). This embodiment differs from the first embodiment and the like in that the rotating plate 4
1 and a configuration for detecting the reference position of the rotating plate 41 thereof. That is, as shown in FIG. 16, the rotating plate 41 in the present embodiment is entirely formed in a disk shape from a conductive material such as a steel plate whose surface is enameled, and specifically, a hub portion in the center portion. An arm portion 41c connects between the outer peripheral frame 41a and the annular peripheral frame (rim portion) 41b.

At this time, the three arm portions 41c are provided radially at intervals of 120 degrees, so that the rotating plate 41 is rotated by 120 degrees (360 degrees / n; n = 3). Has the same rotationally symmetrical shape as the shape of. In addition, as shown in FIG.
A boss portion 41d is provided at the center of the lower surface of the boss 41d, which is connected to a rotation shaft 42 driven by the RT motor 11 at a predetermined rotation direction position. Furthermore, this rotating plate 41
A fan-shaped opening 41e is formed between the arm portions 41c, and the maximum linear dimension e of the opening 41e is set to be at least half the wavelength λ of the microwave. Is formed.

Thus, in the rotating plate 41, the electric field distribution changes due to the wall current being rectified in the direction in which the arm portion 41c extends, and the microwave transmission and transmission due to the position (direction) of the opening 42e. Based on the change in reflection,
The electric field distribution in the heating chamber 2 can be changed with the change of the stop position. Also, at this time, since the rotating plate 41 has the same shape as the original shape when rotated by 120 degrees, the same electric field distribution can be obtained every rotation by 120 degrees.

In the present embodiment, the rotating plate 41 includes:
Two reference positions are set: a first reference position and a second reference position that is 180 degrees symmetric to the first reference position. In this case, as shown in FIG. 17, a single first pin 44 corresponding to a first reference position of the rotating plate 41 is provided on the outer peripheral portion of the upper surface of the gear 43 that rotates integrally with the rotating shaft 42. 2 corresponding to the second reference position of the rotating plate 41.
Second pins 45 of the book are provided.

On the other hand, a transmission type optical sensor 46 is provided at a fixed portion below the oven chamber 1 as a stop position detecting means for detecting the reference position of the rotating plate 41. As is well known, the light sensor 46 is configured by arranging a light projecting element and a light receiving element opposite each other at both ends in a substantially U-shaped holder, and a light blocking object (here, pins 44, 45) is detected. In this case, when the first pin 44 passes through the optical sensor 46 with the rotation of the gear 43, one detection signal is obtained to detect the first reference position, and the second pin 45
Is passed through the optical sensor 46, the second reference position is detected by continuously obtaining two detection signals.

A control circuit (not shown), as in the first embodiment, sets the rotating plate 41 to a predetermined stop position such that an electric field distribution suitable for heating the food F can be obtained according to the type of food. At the position (for example, when the food type is "warm rice"), the cooking is stopped at a position advanced by the angle A from the first reference position, and the heating cooking is executed. At this time, if the position advanced by the angle A from the first reference position is the stop position of the rotating plate 41, the position advanced by an angle A ± 60 degrees from the second reference position is equivalent to the rotating plate 41. Stop position.

Therefore, when the food type is, for example, “warm rice”, the control circuit rotates the rotary plate 41 continuously from an arbitrary initial position. When the first reference position is detected by the optical sensor 46, Angle A from that point
Only when the second reference position is detected by the optical sensor 46, only the angle A ± 60 degrees (minus when the angle A is larger than 60 degrees) from that point in time when the second reference position is detected by the optical sensor 46 The rotating plate 41 is rotated to stop.

Thus, the reference position can be detected by the rotation of the rotary plate 41 within 180 degrees, and the time required for the rotary plate 41 to stop at the stop position is smaller than when only one reference position is provided. Will be shortened. At this time,
The RT motor 10 rotates the rotating plate 41 at a constant speed (60 degrees / second) so as to make one rotation, for example, every 12 seconds. Therefore, the advance angle of the rotating plate 41 from the reference position is converted into the energizing time, and The control of the stop position is performed by controlling the power supply time to the motor 10.

In this embodiment, the control circuit stops the rotary plate 41 at a predetermined stop position to heat the food F, and then rotates the rotary plate 41 by 120 degrees from the stop position to stop. Is repeatedly executed. In this case, one stop time of the rotating plate 41 is set to a fixed time, for example, 10 seconds.
The rotation of degrees (the required time of 4 seconds) and the stop at the stop position for 10 seconds are repeated. At this time, as described above, the rotating plate 41 has the same shape even when rotated by 120 degrees. Therefore, when the rotating plate 41 is stopped, an electric field distribution suitable for heating the food F is always obtained. It is possible to perform cooking while changing the position of the food F (the direction with respect to the excitation port 8).

According to this embodiment, as in the first embodiment, the stop position of the rotary plate 41 is controlled so that heating according to the type of food is performed. Efficient heating according to the type of food F can be performed, and it is possible to perform cooking with a good finish without heating unevenness, and further, such improvement in heating efficiency and improvement in uneven heating. Can be realized only by controlling the stop position of the rotating plate 41, so that an effect that a simple configuration can be achieved can be obtained.

In this embodiment, in particular, the rotating plate 41
Is made to be a rotationally symmetrical shape having the same shape at a rotation of 120 degrees, and after stopping the rotating plate 41 at a predetermined stop position for a certain period of time, rotating the rotation plate 120 from the stop position and stopping it by 120 degrees is repeated. Therefore, the heating can be performed while changing the direction of the food F with respect to the excitation port 8 while always obtaining the electric field distribution suitable for the food F, and the uneven heating can be further reduced. Also, there is an advantage that the rotary plate 41 can be manufactured relatively simply and inexpensively as compared with the case where the shape of the rotating plate 41 is a lattice shape. Since the food F is appropriately rotated, the user does not feel uncomfortable.

Further, in the present embodiment, as the reference position for detecting the position of the rotating plate 41, first and second two signals which generate mutually different detection signals corresponding to the 180 ° symmetric position of the rotating plate are provided. , The time required for detecting one of the reference positions of the rotating plate 41 and stopping at the predetermined stop position can be reduced, and the configuration at that time can be simplified. That is, it is possible to obtain an advantage that it can be completed.

(5) Tenth to fifteenth embodiments FIGS. 18 to 23 show tenth to fifteenth embodiments of the present invention, respectively. These can be said to be modifications of the ninth embodiment, and will be described in order below, focusing on the differences from the ninth embodiment.

FIG. 18 shows a tenth embodiment (corresponding to claim 25) of the present invention.
A cam 51 is provided on the upper surface of the gear 43 which rotates integrally with the gear 2, and a micro switch 52 is provided as a stop position detecting means at a fixed portion below the oven chamber 1. The cam 51 has one first protrusion 51a corresponding to a first reference position of the rotating plate 41,
The first reference position is configured to have two second protrusions 51b corresponding to the second reference position symmetrical by 180 degrees with respect to the first reference position.

Thus, when the rotating plate 41 reaches the first reference position, the first projection 51a of the cam 51 operates the microswitch 52 to generate one detection signal, and the rotating plate 41 When 41 reaches the second reference position, the cam 5
The one second projection 51b operates the microswitch 52 to generate two continuous detection signals. Therefore, similarly to the ninth embodiment described above, it is possible to detect the first and second reference positions of the rotating plate 41 with a simple configuration, respectively.

FIG. 19 shows an eleventh embodiment (corresponding to claim 23) of the present invention. In this embodiment, the reference position of the rotating plate 41 is set to three positions at 120 intervals by utilizing the fact that the rotating plate 41 has the same shape even when rotated by 120 degrees (the same electric field distribution is obtained). It is provided.

The gear 4 that rotates integrally with the rotating shaft 42
Three pins 53 corresponding to the respective reference positions are provided at intervals of 120 degrees on the outer peripheral portion of the upper surface of 3, and these pins 53 are also configured to be detected by the optical sensor 46. In this case, regardless of which of the three pins 53 the optical sensor 46 detects, the reference position is detected, and therefore, the rotation plate 4 is moved from an arbitrary initial position of the rotation plate 41.
The reference position can be detected by rotation within 120 degrees of 1, and the time required for stopping the rotating plate 41 at the predetermined stop position can be further reduced.

FIG. 20 shows a twelfth embodiment (corresponding to claim 23) of the present invention. In this embodiment, three magnetic members 54 such as permanent magnets are provided at intervals of 120 in place of the pins 53 in the eleventh embodiment, and a stop position detection is performed in place of the optical sensor 46 in the eleventh embodiment. A magnetic sensor 55 is provided as a means. When the magnetic sensor 55 detects the approach of the magnetic body 54, the reference position of the rotating plate 41 is detected. With this configuration, the same operation and effect as those of the eleventh embodiment can be obtained.

FIG. 21 shows a rotary plate 61 according to a thirteenth embodiment (corresponding to claim 20) of the present invention. The rotating plate 61 is also configured as a whole from a conductive material such as a steel plate whose surface is enameled, and specifically,
Three arm portions 61 extending radially at 120-degree intervals between a hub portion 61a at the center and an annular peripheral frame 61b.
The shape is connected by c.

A boss 61d is provided at the center of the lower surface of the hub 61a. Further, three openings 61e whose maximum linear dimension e is equal to or more than １ ／ of the wavelength λ of the microwave are formed. Have. The hub 61a is formed with three small openings 61f so as to be shifted from the opening 61e by 60 degrees. Also in this rotary plate 61, like the rotary plate 41 of the ninth embodiment, 12
When rotated by 0 degrees (360 degrees / n; n = 3), the shape is the rotationally symmetric shape which becomes the same shape as the original shape, and the same operation and effect can be obtained.

FIG. 22 shows a rotary plate 71 according to a fourteenth embodiment (corresponding to claim 20) of the present invention. This rotary plate 71 has a hub portion 71a at the center and an annular peripheral frame. 7
1b is connected by four arm portions 71c extending radially at 90-degree intervals. This rotating plate 7
Numeral 1 is a rotationally symmetric shape which becomes the same shape as the original shape when rotated by 90 degrees (360 degrees / n; n = 4).
Also, when rotated by an integral multiple of 90 degrees (180 degrees, 270 degrees), the shape becomes the same as the original shape.

FIG. 23 shows a rotary plate 81 according to a fifteenth embodiment (corresponding to claim 20) of the present invention. This rotary plate 81 is provided with a hub portion 81a at the center and an annular peripheral frame. 8
1b is connected by five arms 81c extending radially at intervals of 72 degrees. This rotating plate 8
Numeral 1 is a rotationally symmetric shape having the same shape as the original shape when rotated 72 degrees (360 degrees / n; n = 5).
In addition, even when rotated by an angle that is a positive multiple of 72 degrees, the shape becomes the same as the original shape.

The rotary plate 71 or the rotary plate 81 is also stopped at a predetermined stop position where heating according to the type of food is performed, and after stopping at the stop position for a predetermined time, the stop position is changed from the stop position. 90 degrees or its integral multiple (1
80 degrees, 270 degrees), or 72 degrees or an integral multiple thereof (144 degrees, 216 degrees, 288 degrees), and repeatedly stopping, thereby always obtaining an electric field distribution suitable for food F. The same as in the ninth embodiment and the like described above, in which efficient heating can be performed, heating can be performed while changing the direction of the food F with respect to the excitation port 8, and uneven heating can be further reduced. The effect can be obtained.

The present invention is not limited to the embodiments described above, but can be implemented with appropriate modifications without departing from the scope of the invention. In this case, although illustration is omitted, in each of the above-described embodiments, when the stop plates 9 and 31 are stopped at the predetermined stop positions and the stop heating mode in which the food F is heated is executed, the rotation plates 9,31 to 180
It is also possible to perform a control to execute an operation of rotating by one degree and stopping the rotation (corresponding to claim 26).

According to this, even when the irradiation of the microwave to the food F from one surface direction is strong and the opposite surface of the food F is shaded, the food F is not affected during the heating.
Is inverted by 180 degrees, so that microwave irradiation on both surfaces can be equalized.
At this time, since the rotating plates 9 and 31 have a point-symmetrical shape, heating can be performed with an optimal radio wave distribution without changing the mode of the radio wave distribution.

Although not shown, for example, for heavy foods, the heating time naturally increases, but if only heating in the stop heating mode is performed for a long time, uneven heating may occur. . Therefore, until the predetermined heating time, the rotary plate is stopped at a predetermined stop position corresponding to the food type to heat the food, and after the predetermined heating time, the food is heated while rotating the rotary plate. A configuration may be adopted (corresponding to claim 5). According to this, it is possible to reduce uneven heating when performing heating for a long time.

In each of the above embodiments, the rotary plate is stopped at the predetermined stop position based on the power supply time to the RT motor after the reference position of the rotary plate is detected.
The stop position of the rotating plate may be controlled based on the amount of electric power input to the motor. Further, various modifications are possible for the shape of the rotating plate and the configuration for detecting the reference position. .

[0108]

As is apparent from the above description, according to the microwave oven of the present invention, the rotating plate provided at the bottom of the heating chamber and supporting the food is formed in a non-homogeneous shape in the rotating direction from the conductive material. In addition to the configuration, the stop position of the rotating plate is provided with control means for controlling the heating according to the food, so that the heating efficiency can be improved and the heating unevenness can be improved. This provides an excellent effect that a simple configuration can be used.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention, and is a flowchart showing a control procedure of a rotating plate.

FIG. 2 is a block diagram schematically showing an electrical configuration.

FIG. 3 is a schematic perspective view of a heating chamber.

FIG. 4 is a perspective view showing a stop position of a rotary plate suitable for warming rice (a) and a stop position of a rotary plate suitable for sake can (b).

FIG. 5 is a plan view of a rotating plate.

FIG. 6 is a perspective view of a main part in a heating chamber showing an optical sensor part.

FIG. 7 is a view corresponding to FIG. 1, showing a second embodiment of the present invention;

FIG. 8 is a view corresponding to FIG. 6, showing a third embodiment of the present invention.

FIG. 9 is a view corresponding to FIG. 6, showing a fourth embodiment of the present invention.

FIG. 10 is a perspective view of a rotary shaft showing a fifth embodiment of the present invention.

FIG. 11 is a perspective view of a rotating plate (food dish) showing a sixth embodiment of the present invention.

FIG. 12 is a view corresponding to FIG. 11, showing a seventh embodiment of the present invention;

FIG. 13 is a view corresponding to FIG. 5, showing an eighth embodiment of the present invention.

FIG. 14 is a perspective view showing a state inside a heating chamber.

FIG. 15 is a longitudinal sectional front view schematically showing the configuration of the lower half of the heating chamber.

FIG. 16 is a view corresponding to FIG. 5, showing a ninth embodiment of the present invention;

FIG. 17 is a diagram corresponding to FIG. 10;

FIG. 18 is a view corresponding to FIG. 10, showing a tenth embodiment of the present invention;

FIG. 19 is a view corresponding to FIG. 10, showing an eleventh embodiment of the present invention;

FIG. 20 is a view corresponding to FIG. 10, showing a twelfth embodiment of the present invention;

FIG. 21 is a view corresponding to FIG. 5, showing a thirteenth embodiment of the present invention;

FIG. 22 is a view corresponding to FIG. 5, showing a fourteenth embodiment of the present invention;

FIG. 23 is a view corresponding to FIG. 5, showing a fifteenth embodiment of the present invention;

[Explanation of symbols]

In the drawing, 2 is a heating chamber, 4 is a control circuit (control means), 5 is a magnetron (microwave supply means), 8 and 34 are excitation ports, 9, 31, 41, 61, 71 and 81 are rotating plates, 9
a and 31a are peripheral frames, 9b and 31b are vertical bars, 9c and 31
c is a horizontal bar, 9e, 31e, 41e are openings, 10, 2
5, 42 are rotating shafts, 11 is an RT motor (drive mechanism), 1
2 is a food placing plate, 14, 21, 46 are optical sensors, 24,
55 is a magnetic sensor, 27 and 52 are switches, 28 and 29
Is a mark, 30 is a spotlight, 32 is a central opening,
33 is a waveguide, 33a is a wall portion, 35 is a raised portion, 44,
45 and 53 are pins, 51 is a cam, 54 is a magnetic material, and F is food.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H05B 6/78 H05B 6/78 A

Claims (26)

[Claims] 1. A heating chamber, microwave supply means for supplying microwaves into the heating chamber, and a rotating member which is formed in a non-homogeneous shape in a rotating direction from a conductive material and is provided at a bottom portion of the heating chamber to support food. A microwave oven comprising: a plate; a drive mechanism for driving the rotary plate to rotate; and control means for controlling a stop position of the rotary plate so that heating according to food is performed. 2. The electronic device according to claim 1, wherein the control means stops the rotary plate at a predetermined stop position according to the food type input by the user or automatically determined by the user to perform heating. range. 3. A rotary heating mode in which the food is heated while rotating the rotary plate, and a stop heating mode in which the rotary plate is stopped at a predetermined stop position to heat the food, wherein the heating is performed according to the type of food. 3. The microwave oven according to claim 1, wherein a mode is selected. 4. A combined heating mode in which heating of food in a state where the rotating plate is stopped at a predetermined stop position and heating of food while rotating the rotating plate is performed in accordance with the type of food. 4. The microwave oven according to claim 1, wherein the microwave oven is executed. 5. The control means heats the food by stopping the rotary plate at a predetermined stop position until a predetermined heating time, and heats the food while rotating the rotary plate after the predetermined heating time. The microwave oven according to claim 1 or 2, wherein: 6. A stop position detecting means for detecting a stop position of the rotary plate, wherein the control means controls the stop position of the rotary plate based on a detection result of the stop position detecting means. Item 6. The microwave oven according to any one of Items 1 to 5. 7. The stop position detecting means is configured to detect a reference position of the rotary plate, and the control means includes:
7. The microwave oven according to claim 6, wherein the rotating plate is stopped at a predetermined stop position according to a rotation driving time from a reference position of the rotating plate. 8. The microwave oven according to claim 6, wherein the stop position detecting means is configured using an optical sensor. 9. The microwave oven according to claim 6, wherein the stop position detecting means is configured using a magnetic sensor. 10. A stop position detecting means indirectly detects a stop position of a rotary plate by detecting an angle of a rotary shaft connected to the rotary plate at a predetermined rotation direction and rotating the rotary plate. The microwave oven according to any one of claims 6 to 9, wherein: 11. A rotating plate or a food placing plate set on the rotating plate, a mark indicating a position suitable for placing food is displayed.
The microwave oven according to any one of the above. 12. The microwave oven according to claim 11, wherein the mark is displayed by irradiating a spotlight. 13. The rotating plate has a lattice shape having a vertical bar and a horizontal bar perpendicular thereto in a surrounding frame, wherein the vertical bar extends continuously in one direction, and the horizontal bar has one length. The microwave oven according to any one of claims 1 to 12, wherein the microwave oven is divided so as to have a length of less than half the microwave wavelength. 14. A rotating plate has a lattice shape having a vertical bar and a horizontal bar perpendicular thereto in a peripheral frame, and a central opening having a length of at least １ ／ of a microwave wavelength in both the vertical and horizontal directions at a central portion thereof. 14. The method according to claim 1, wherein:
The microwave oven according to any one of the above. 15. An excitation port for supplying microwaves into the heating chamber, wherein the height of the side wall of the heating chamber from the rotating plate is set to a position of not more than １ ／ of the microwave wavelength. The microwave oven according to claim 14, characterized in that: 16. A wall portion connected to a lower end of an excitation port at an exit portion of a waveguide for guiding microwaves into a heating chamber has a shape inclined downward toward the excitation port. 15. The microwave oven according to 15. 17. The microwave oven according to claim 14, wherein a bottom portion of the heating chamber has a shape corresponding to a central portion of the rotating plate, and is formed in a mountain shape. . 18. A rotating plate having a rectangular opening in a portion near an outer periphery in which a vertical direction is equal to or more than の of a microwave wavelength and a horizontal direction is less than １ ／ of a microwave wavelength. The microwave oven according to any one of claims 14 to 17, wherein: 19. The rotary bar according to claim 13, wherein the vertical bars of the grid of the rotating plate are provided so as to extend continuously in one direction from the end to the end in the surrounding frame. The microwave oven as described. 20. The rotating plate according to claim 1, wherein the rotating plate has a rotationally symmetric shape which becomes the same as the original shape when rotated by 360 / n degrees (n is an integer of 2 or more). The microwave oven according to any one of the above. 21. The control means, wherein the rotating plate is stopped at a predetermined stop position, the food is heated, and then the rotating plate is rotated 360 / n degrees from the stop position to stop. The microwave oven according to claim 20, wherein 22. The microwave oven according to claim 21, wherein a single stop time at each stop position is constant. 23. Stop position detecting means for detecting a reference position of the rotating plate, wherein n reference positions for generating the same detection signal are provided evenly in a circumferential direction of the rotating plate. The microwave oven according to any one of claims 20 to 22, wherein: 24. The apparatus according to claim 20, further comprising stop position detection means for detecting a reference position of the rotating plate, wherein a plurality of reference positions are provided for generating different detection signals. The microwave oven according to any one of the above. 25. The apparatus according to claim 24, wherein the two reference positions are provided so as to generate different numbers of detection signals corresponding to the 180-degree symmetric positions of the rotating plate. microwave. 26. The control means, when the rotating plate is stopped at a predetermined stop position and the food is being heated, the rotating plate is rotated by 18 degrees.
The microwave oven according to any one of claims 13 to 25, wherein the operation of rotating by 0 degrees and stopping is performed at least once.