JP2001304573A - High frequency cooking device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To efficiently perform a numerical analysis of an electromagnetic field in a refrigerator including an object to be heated, and always perform optimal heating based on an analysis result. An object to be heated 1 housed in a microwave oven is placed on a turntable 4. In addition, a shape recognition sensor 9 for recognizing the shape of the object to be heated 1 is provided in the refrigerator. The microcomputer 13 creates an electromagnetic field model in the refrigerator using information including shape information indicating the shape of the object to be heated 1 based on the recognition result of the sensor 9 at the time of heating and cooking. Then, physical property value information indicating the value of the physical property of the object to be heated 1 is assigned, and a numerical analysis process is performed to calculate a heating sequence to be applied to heating cooking. At this time, the shape information is as follows.
Thus, the shape of the object to be heated 1 can be recognized with a small number of sensors 9 while being detected by the sensor 9 while rotating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency heating cooking device, and more particularly to a cooking object that recognizes a cooking object, predicts a heating state by numerical analysis using the recognition result, and selects a cooking procedure based on the prediction result. And a high-frequency heating cooking device that performs a heating operation in accordance with a selected cooking procedure.

[0002]

2. Description of the Related Art Conventional microwave ovens for home use include:
The heating control is performed while measuring the surface temperature of the object to be heated using an infrared sensor composed of an element or a plurality of elements. Further, the heating sequence is determined by selecting the weight of the object to be heated or the type of food to be heated by the user in advance, and heating and thawing are performed according to the determined heating sequence.

[0003]

However, at the time of heating and thawing using microwaves, the infrared sensor can measure only the surface temperature, and even if the microwaves are controlled based on the information, the inside of the object to be heated can be measured. It is unknown whether the heating has been performed until the user actually confirms. Also, heating and thawing in a heating sequence determined by the type and weight of the food is not completely satisfactory. This is because, for example, when thawing meat, both meats of the same weight are thawed according to the same sequence, regardless of the shape, the ratio of lean to lean, the place placed in the oven that is the heating room of the microwave oven, etc. Is done.

In a numerical analysis method of an electromagnetic field using the FDTD method (short for finite difference time domain method), it is necessary to first model an object to be analyzed. Here, it is necessary that the model is a hexahedral orthogonal lattice as a condition for modeling.
In order to model the inside of the microwave oven, the shape, material, and the like of the housing, turntable, waveguide, etc. are known in advance. Physical properties) are various,
The problem is how to grasp these.

[0005] Therefore, when the heating and thawing method using the FDTD method disclosed in Japanese Patent Application Laid-Open No. 9-232720 is used, many shape recognition sensors are used for shape recognition of an object to be heated. Is fixed on the inner surface of the refrigerator, so it can only recognize the object to be heated with a limited resolution.In the case of an object with a complicated shape, accurate shape recognition, that is, accurate modeling Can not.

Therefore, for accurate modeling, the number of meshes may be increased with respect to the above-described hexahedral orthogonal lattice.
In this case, the analysis time and the used memory capacity increase, and real-time numerical analysis becomes impossible.

[0007] Therefore, an object of the present invention is to provide a high-frequency heating and cooking apparatus capable of efficiently performing a numerical analysis of an electromagnetic field in a refrigerator including an object to be heated and always performing optimal heating based on the analysis result. To provide.

[0008]

According to one aspect of the present invention, a heating sequence applied to heat and cook an object to be heated housed in a high-frequency heating chamber according to an aspect of the present invention by a high frequency wave is described in a heating chamber in which an object to be heated is housed. The high-frequency heating and cooking apparatus calculated by using the electromagnetic field model for has the following features.

That is, a rotating means for rotating an object to be heated housed in the heating chamber, and a rotating means provided in the heating chamber,
A shape sensor for recognizing the shape of the object to be heated accommodated in the heating chamber, and information including shape information indicating the shape of the object to be heated based on the recognition result of the shape sensor for the heating chamber accommodating the object to be heated. A numerical analysis process is performed by assigning physical property value information indicating physical property values of the object to be heated to a model creating means for creating an electromagnetic field model, and to the electromagnetic field model created by the model creating means. Analysis means for calculating the heating sequence by using

The shape information indicates the shape of the object to be heated detected by the shape sensor while rotating the object to be heated by the rotating means.

Therefore, in the high-frequency heating cooking apparatus, the shape information is obtained by being detected by the shape sensor while rotating the object to be heated by the rotating means, so that the shape of the object to be heated is recognized with a small number of shape sensors. be able to.

Further, since the heating sequence to be applied is calculated and determined each time heating and cooking is performed, it is not necessary to prepare a large amount of heating sequence data in advance.

In the above-described high-frequency heating cooking device, the shape sensor is provided movably in the heating chamber.

In the above-described high-frequency heating cooking apparatus, a plurality of shape sensors are provided in the heating chamber.

Therefore, since the shape sensor moves freely or is provided in plural, the shape of the object to be heated can be recognized without restriction of the resolution, and the electromagnetic field model can be created with higher accuracy.

In the above-described high-frequency heating cooking apparatus, an image sensor provided in the heating chamber for recognizing an image of the object to be heated accommodated in the heating chamber, and image information of a plurality of different types of the object to be heated are provided. And a memory unit in which corresponding physical property value information is stored in advance. Then, based on the information of the image of the object to be heated according to the recognition result of the image sensor, the physical property value information corresponding to the object to be heated is read from the memory unit.

Therefore, it is possible to easily obtain the physical property value information of a plurality of types of objects to be heated, and to easily apply the numerical analysis processing to various foods.

In the above-described high-frequency heating cooking apparatus, the analyzing means repeats the numerical analysis processing during the cooking.

Therefore, even during the cooking, the numerical analysis process is repeated, so that the applied heating sequence is updated to be optimal, and a better heating state can be provided.

The analysis by the analysis means may be executed at the same time as the start of cooking. Therefore,
Even if the analysis is a complicated electromagnetic field model that takes a long time, the cooking time including the analysis time can be reduced.

In the above-described high-frequency heating cooking apparatus, when the electromagnetic field model has symmetry with respect to the boundary, the analyzing means performs a numerical analysis process on one part symmetric with respect to the boundary of the electromagnetic field model. You.

Therefore, since the space of the electromagnetic field model to be analyzed can be reduced to half, the analysis time can be reduced to half and the analysis result, that is, the heating sequence to be applied can be calculated quickly.

In the above-described high-frequency heating cooking apparatus, the electromagnetic field model is composed of a hexahedral orthogonal lattice, and the lattice corresponding to the object to be heated is subdivided.

Therefore, even if a food having a complicated shape is an object to be heated, the grid can be finely set only in the portion of the food, so that the analysis can be performed accurately and in a short time.

The above-described high-frequency heating and cooking apparatus further includes a temperature sensor provided in the heating chamber for detecting the temperature of the object to be heated housed in the heating chamber.
During the cooking, the analysis unit is controlled so as to reassign the physical property value information based on the detection result of the temperature sensor and execute the numerical analysis process.

Therefore, the temperature sensor detects a change in the temperature of the object to be heated, which changes as the cooking proceeds, and the relative permittivity of the object to be heated due to the temperature change can be easily calculated. The numerical analysis can be performed by reassigning the relative permittivity to the electromagnetic field model. Therefore, even during the heating cooking, an optimal heating sequence according to the temperature distribution of the object to be heated is applied, and the failure of the heating is avoided.

The above-described high-frequency heating and cooking apparatus further includes a reflector movably provided for reflecting high-frequency waves in the heating chamber, and the position and angle of the reflector are determined based on the result of numerical analysis by the analyzing means. Adjusted.

Therefore, the reflector is adjusted to a position and an angle for efficiently reflecting the high frequency for the heating and cooking, thereby enabling efficient and uniform heating.

The above-described high-frequency heating and cooking apparatus further includes a waveguide having a freely movable stub for suppressing a reflected wave with respect to a high-frequency traveling wave in order to supply a high-frequency wave into the heating chamber. The position of the stub is adjusted based on the result of the numerical analysis by the analysis means.

Therefore, the stub is adjusted to the optimal position for heating each time heating is performed. Therefore, even if the object to be heated is small and the load is small, the reflected wave is reduced and the load related to the supply of high frequency is reduced. Is reduced,
The cooking time is reduced.

In the above-described high frequency heating cooking apparatus, based on the image information of the object to be heated according to the recognition result of the image sensor,
The state of the object to be heated in the heating chamber is notified.

[0032] Therefore, the user who has confirmed the content of the notification, confirms that the heating cooking is started in a state where the object to be heated is not accommodated (no load state) or in a state in which metal discharge or the like occurs. Knowing in advance, it can be processed to avoid this.

[0033] The above-described high-frequency heating cooking apparatus further includes an input means for inputting information relating to the cooking.
During the heating cooking, the result of the numerical analysis processing by the analysis means according to the progress of the heating cooking is output.

Therefore, the heating condition can be easily confirmed by numerical information, and the user operates the input means according to the confirmation result to reach, for example, a desired heating state (temperature). At this point, the cooking can be stopped.

The above-described high-frequency heating cooking apparatus further includes finished state output means for outputting a finished state of the object to be heated based on each of the plurality of types of heating sequences obtained by the analyzing means. A heating sequence corresponding to a desired type of finished state among the plurality of types of finished states is applied to the heating cooking.

Accordingly, the user can select a desired heating sequence from a plurality of applicable heating sequences and apply the selected heating sequence to the cooking.
It is possible to provide a finished state according to the user's preference.

[0037]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) First, Embodiment 1 will be described.

FIG. 1 is a schematic hardware configuration diagram of a microwave oven according to each embodiment of the present invention. FIG. 2 is a functional configuration diagram of the microwave oven according to each embodiment of the present invention. FIGS. 3A and 3B are flowcharts of a heating process according to each embodiment of the present invention. FIG. 4 is a configuration diagram of an image sensor according to each embodiment of the present invention.
FIGS. 5A to 5C are diagrams illustrating a procedure for forming a mesh in the FDTD method.

In FIG. 1, the microwave oven has a turntable 4 on which an object 1 to be heated is placed and rotated in a refrigerator.
It has a reflector 5, an image sensor 6, and a temperature sensor 7 provided on the upper surface, and has a plurality of shape recognition sensors 9 provided on a side wall surface in the refrigerator. Outside the refrigerator, a turntable motor 4A for rotating the turntable 4, a reflector driving circuit 8 for driving the reflector 5, and a shape recognition sensor driver 10 for driving and moving the shape recognition sensor 9 are provided. , Stub 11 and stub drive circuit 12 for driving stub 11, and microcomputer for centrally controlling and monitoring the microwave oven 13 are provided.

Here, the shape recognition sensor 9 is attached to the side surface inside the microwave oven, but the shape recognition sensor 9 may be attached to the upper part inside the microwave oven.

In FIG. 2, a microwave oven is
1. A microcomputer 13 including a processing unit 132, a memory 134, and a communication unit 135 for communicating with an external device inputs information provided from the shape recognition sensor 9, the image sensor 6, the temperature sensor 7, and the input unit 15. , Processing is performed according to a predetermined procedure, and the processing result is provided to the driving unit 14 and the output unit 16. The drive unit 14 is configured to control the turntable 4, the reflector 5, the magnetron 3, the stub 1 based on information given from the microcomputer 13.
1. The shape recognition sensor 9 and the temperature sensor 7 are driven. The input unit 15 is made up of keys provided on the front of the microwave oven for externally operating the user to input information. The output unit 16 includes an LCD (Liquid Crystal Display) for displaying information as an image to the user, an audio output unit, and the like. The drive unit 14 is configured to include the turntable motor 4A, the reflection plate drive circuit 8, the shape recognition sensor drive unit 10, and the stub drive circuit 12 in FIG.

In FIG. 1, a plurality of shape recognizing sensors 9 are installed in the vertical direction on the side surface inside the refrigerator. Here, it is assumed that the shape recognition sensor 9 is installed at a fixed position without moving.

Next, the operation of the microwave oven will be described with reference to the flow charts of FIGS. First, step S
At 0, when the user presses a heating start button (not shown) of the input unit 15, the turntable 4 makes one rotation,
In step S1, the shape of the object to be heated 1 placed thereon is detected by the shape recognition sensor 9. Shape recognition sensor 9
Is composed of a distance measuring sensor and the like. An image is captured by the image sensor 6 together with the shape recognition sensor 9. The obtained information is given to the microcomputer 13.

In step S2, the microcomputer 13 creates the above-mentioned mesh to construct a model that can be handled by the FDTD method based on the provided information. The number of meshes to be produced is determined by the number of shape recognition sensors 9 in the height direction, but can be infinite in the horizontal direction. Here, if the number of meshes is increased,
Can be expressed with high precision. However, FDTD
The numerical analysis time by the method becomes longer.

Therefore, it is necessary to set the number of meshes to a desired number in consideration of the numerical analysis time. Therefore, the size of the mesh is increased for the heating target 1 having a simple shape, and the mesh is slightly reduced for the heating target having a complicated shape. Thereby, the shape recognition sensor 9
Is calculated by the calculation unit of the microcomputer 13 and the FDTD
An optimally sized mesh for the method is created.

Here, the configuration is such that the shape of the object 1 to be heated is recognized by the fixed shape recognition sensor 9 while the turntable 4 is rotating. The shape of the object to be heated 1 can be accurately recognized. Here, a plurality of shape recognition sensors 9 are provided, but the same effect can be obtained with one.

In the above-mentioned microwave oven, since the fixed shape recognition sensor 9 is used, the mesh cannot be finely divided in the height direction. However, the shape recognition sensor 9 is movable by the shape recognition sensor driving unit 10. By using the formula, the number of mesh divisions can be freely determined in the height direction. Here, as described above, the case where the shape recognition sensor 9 is installed on the inside surface of the refrigerator will be described, but the same applies to the case where the shape recognition sensor 9 is mounted on the upper portion of the refrigerator.

First, as shown in FIG. 1, one or more shape recognition sensors 9 which can be freely moved by a shape recognition sensor driving unit 10 are provided on the inner side surface of the refrigerator. The shape recognition sensor drive unit 10 moves the shape recognition sensor 9 up and down on the inner side surface using a stepping motor or the like.

The turntable 4 on which the object to be heated 1 is placed in advance starts rotating immediately after the user presses a start button (not shown) of the input unit 15, and at the same time, the shape recognition sensor 9 is driven by the shape recognition sensor. The vertical drive is started by the unit 10. In this way, while the turntable 4 makes one rotation, the shape of the object to be heated 1 is recognized by the shape recognition sensor 9 in the same manner as described above. At this time, since the shape recognition sensor 9 moves in the vertical direction, there is no restriction on the resolution in the vertical direction in shape recognition, and an accurate model can be obtained by arbitrarily dividing the mesh into the object 1 having a complicated shape. Production becomes possible.

When a shape recognition sensor 9 that can move in the lateral direction is installed in the upper part of the inside of the microwave oven, the turntable 4 on which the object to be heated 1 is mounted is rotated, thereby Similarly, an accurate model can be produced.

Here, by providing a plurality of shape recognition sensors instead of one, the shape recognition time of the object to be heated can be further shortened.

After the inside of the microwave oven including the object 1 to be heated is modeled as described above, it is necessary to specify the physical property values for each mesh. Here, the image sensor 6 is installed in the upper part of the refrigerator, and the turntable is set so that the entire field of the object 1 to be heated is included in the field of view of the image sensor 6 or a part of the object to be heated 1 is included in the field of view. 4 to 1
By rotating, the object to be heated 1 is installed so as to be recognized.

Here, the configuration of the image sensor 6 will be described with reference to FIG. The image sensor 6 includes an image input unit 61 including a sensor unit 62 and a preprocessing circuit 63, an A / D conversion circuit 64, a signal processing unit 65, an image memory 66, and a comparison operation unit 6.
8 and an image processor 67 including a memory 69. An image of the object to be heated 1 is input by the sensor unit 62 for inputting visible light from the object to be heated 1 and the preprocessing circuit 63, and an image signal obtained by the input is converted into a digital signal by the A / D converter 64. Signal processing unit 6
5 given. The signal processing unit 65 separates the applied digital signal into a luminance signal and a chrominance signal, and
To memorize. Thereafter, the image processor 67 processes the video signal recorded in the image memory 66 by the comparison operation section 68 using the video signal, and based on the information such as the shape and color of the heated object 1, Identify the type of

In this way, even when a packaged food item whose contents cannot be seen, for example, a commercially available frozen food product, is placed on the turntable 4 as the object to be heated 1, it is referred to by the comparison operation section 68. If these data are stored in the memory 69 in advance as food data, the comparison operation unit 68 compares the processing result described above with the contents of the memory 68 to determine what food and what shape from the package design and the like. Can be easily determined.

Based on the determination result information, for the packaged food, the corresponding shape and physical property values are read from existing data (data stored in the memory 69), and the placed position is determined by the image sensor 6 or the shape recognition sensor 9. And model based on the information. In the case of other foods, for example, beef, the shape was determined by using the shape recognition sensor 9 as described above, and the physical property value was obtained by recognizing the red portion and the fat portion by the processing of the image sensor 6. Assign each property value to the mesh. Therefore, the physical characteristics of not only ordinary food but also packaged commercial food can be recognized.

When the creation of the mesh and the input of the physical property values are completed by modeling the inside of the microwave oven as described above, an analysis based on the information of the obtained model is performed in step S3. This analysis is an analysis of the electromagnetic field in the refrigerator according to the FDTD method. The general procedure of this analysis is as follows:
This is shown in FIG.

The timing for performing the electromagnetic field analysis is as follows.
The user places the article to be heated 1 in the microwave oven,
After pressing the heating start button 5, the turntable 4 is rotated, and the analysis starts when the image sensor 6 and the shape recognition sensor 9 model the object 1 to be heated.

When the analysis is completed, a heating sequence is obtained as a result of the analysis. In step S4, heating is actually started using the magnetron 3 in accordance with the obtained heating sequence. Here, if the object to be heated 1 has a simple shape, the analysis time is about several seconds. However, if the object has a complicated shape, the mesh is set finely. In some cases, it may take too long to start heating. In that case, heating is started for the time being and electromagnetic field analysis is started simultaneously with heating. Since the analysis time is very short as compared with the heating end time, there is sufficient time for various controls for heating when the electromagnetic field analysis is completed.

As described above, when analyzing a complicated model that requires time, this analysis is performed simultaneously with the heating, so that the heating time including the analysis time can be reduced.

Here, electromagnetic wave analysis is performed using the FDTD method. In performing electromagnetic wave analysis, there is a problem of how to reduce the analysis time. The time saving is
It depends on how to reduce the number of meshes created for the analysis model. As one of the methods,
When the object to be heated has symmetry, a so-called symmetric boundary condition is used. In the case of a left-right symmetric model, this is a method in which the model is divided into halves on the plane of symmetry and only one is analyzed, so that the same analysis result as that obtained by analyzing the entire model can be easily obtained. . By using this method, the space to be analyzed can be halved, and the analysis time is halved.

As other methods for shortening the analysis time, there are a so-called non-uniform cell analysis method shown in FIG. 5C and a sub-cell analysis method shown in FIG. 5B. In the former, when making the mesh, by reducing the size of the mesh only in the portion to be heated 1, the portion without the object to be heated 1 can be composed of a relatively large mesh, so that the analysis time can be reduced without lowering the analysis accuracy. It has the feature that it can be shortened. The latter sub-cell analysis method is basically a method of analyzing a uniform cell in FIG. 5A, but is a method of partially dividing a cell into several parts. In other words, for example, even a single cell can be divided, and the effect of reducing the number of meshes is greater than in the former non-uniform cell analysis method, so that the analysis time is reduced. By using such a method, it is possible to perform electromagnetic wave analysis with high accuracy and in a short time.

As described above, even with respect to the heated object 1 having a complicated shape, the cell relating to the analysis model can be made fine only in the portion of the heated object 1, so that the analyzing process can be performed accurately and in a short time.

Next, the heating sequence is calculated from the result of the electromagnetic wave analysis performed in step S3. How to calculate the heating sequence will be described.

Operation unit 131 of microcomputer 13
Performs an accurate modeling of the inside of the microwave oven including the object to be heated 1 as described above, executes an analysis for each predetermined step, and sequentially writes the analysis results for each step to the memory 134. To save. Based on these results, the electromagnetic field distribution on the surface and inside of the object to be heated 1 with respect to the obtained time is converted into an absolute temperature distribution including heat conduction using physical property values and information detected by the temperature sensor 7.
If it is determined based on the obtained absolute temperature distribution that a temperature difference of a certain value or more occurs between the lowest temperature portion and the highest temperature portion of the article to be heated 1, the arithmetic section 131 controls the drive section 14. Then, control is performed so that the output of the microwave by the magnetron 3 is reduced. Thereby, the temperature of the article 1 to be heated in the refrigerator becomes uniform while utilizing the heat conduction.

As described above, since the heating sequence is calculated each time heating is performed, it is not necessary to store a large amount of sequence data, and it is possible to apply the optimal sequence to various objects 1 to be heated and thaw. .

On the other hand, the arithmetic unit 131 rotates the turntable 4 via the drive unit 14 and prepares an analytical model in a state where the object 1 is rotated at intervals of about 30 to 45 °. Each model may be analyzed by applying the above-described analysis routine, and the temperature distribution of the object to be heated 1 with respect to the rotation angle may be obtained based on the analysis result. Then, by controlling the rotation angle of the turntable 4 via the drive unit 14 based on the obtained temperature distribution information,
Further, the object to be heated 1 can be uniformly heated.

When heating proceeds in accordance with the heating sequence calculated in this manner, the physical properties of the article to be heated 1 change with the ambient temperature increased by heating.
Specifically, as the temperature rises, the dielectric constant, which is the physical property value of the object 1 to be heated, also increases, and microwaves are easily absorbed in the portion where the dielectric constant is increased, which further increases the dielectric constant. The repetition causes uneven heating of the article to be heated 1.

The above-described change in the dielectric constant of the object to be heated 1 can be predicted to some extent by the above-described analysis and can be reflected in a value for the analysis process. However, depending on the accuracy of the analysis model, An error may occur depending on whether the model was correctly modeled.

Therefore, the temperature sensor 7 is made movable via the drive unit 14 in step S6. The arithmetic unit 131 measures the surface temperature distribution of the object to be heated 1 while moving the temperature sensor 7 via the drive unit 14, and acquires the measurement result via the processing unit 132, and actually obtains the measurement result at that time. The dielectric constant of the object to be heated 1 with respect to the temperature is calculated, and the physical properties of the model are sequentially changed in step S7 using the calculated result. The model thus changed is subjected to the electromagnetic wave analysis as described above in step S8.
Until a predetermined heating end time is reached (Y in step S9).
The heating sequence is recalculated, and the heating sequence is corrected so that the object to be heated 1 is brought into a preferable heating state.

Therefore, by correcting the analysis result, the influence of the analysis accuracy is reduced and a uniform finish is obtained.

(Embodiment 2) In the processing of Embodiment 1 described above, the angle and position of the reflector 5 are controlled to
A more preferable heating sequence may be obtained.

Here, the reflecting plate 5 installed in the upper part of the microwave oven has a heater function and also has a function of reflecting microwaves applied to the interior of the microwave oven.
The reflection angle or height of the reflection plate 5 is arbitrarily changed via the drive unit 14. Therefore, by changing the parameters of the height and angle of the reflection plate 5, it is possible to analyze the electromagnetic waves in the refrigerator according to the FDTD method. Based on the values obtained as a result of the analysis, the optimum position and angle of the reflector 5 are calculated, and based on the calculated values, the calculation unit 131 controls the position of the reflector 5 via the drive unit 14 and performs heating. Perform the operation.

At this time, among the obtained analysis results, the most effective result in the temperature distribution of the object 1 to be heated, that is, the temperature rise and the position and angle of the reflector 5 having the best temperature distribution in the temperature distribution, are used. The reflection angle or position of the reflection plate 5 in the microwave oven is determined. In this way, optimal heating can always be performed regardless of the shape of the object 1 to be heated.

In this case, the reflector 5 is installed in the upper part of the storage. However, the movable reflector 5 may be installed in the vicinity of the opening 2A formed inside the storage of the waveguide 2. It is possible, and by doing so, the same effect as described above can be obtained.

The initial position and angle of the reflector 5 described above are derived from the analysis results. However, when heating actually proceeds, uneven heating occurs in the object 1 due to the temperature characteristics of the dielectric.

Therefore, it is preferable to control the position and angle of the reflector 5 sequentially even during heating. Here, the dielectric of the model of the object to be heated 1 is changed according to the temperature based on the temperature distribution information obtained by the analysis as described above.
Then, analysis is performed on each of several models in which the position of the reflector 5 is changed again, and the position and angle of the reflector 5 corresponding to the model under the condition where the temperature of the object to be heated 1 is the most uniform are determined. Adopted for position and angle. Such processing is repeated, the optimal position and angle of the reflector 5 are calculated in parallel with the heating operation, and the position and angle of the reflector 5 based on the calculation result are controlled sequentially in parallel. Good. The calculation of such a series of procedures is referred to as a calculation method of the position control sequence of the reflector 5 here.

The position and angle of the reflector 5 may be adjusted as follows. First, as described above, the temperature distribution on the surface of the object to be heated 1 during heating is measured,
By reflecting the obtained permittivity on the permittivity of the analysis model, an accurate analysis result can be obtained. Then, using the position control sequence calculation method for the reflector 5 based on the analysis result, the reflector position control sequence is derived again and replaced with the reflector position control sequence calculated before heating, thereby further improving accuracy. Good heating can be performed.

As described above, by moving the reflection plate 5 to the optimum position and angle according to the object 1 to be heated, efficient and uniform heating can be achieved. In addition, since fine control can be performed in accordance with time, a more uniform finish can be achieved.

Third Embodiment Next, a third embodiment will be described. In the third embodiment, the position of the stub 11 is controlled to be optimal.

In the above-described embodiment, when the object to be heated 1 is small, for example, when one cup is heated, the reflected wave tends to increase with respect to the traveling wave of the microwave in the waveguide 2. . As one of the usual methods to avoid this, the stub 11 is provided in the waveguide 2 at a position where the reflected wave is minimized. Since the stub 11 is fixedly installed when the microwave oven is shipped, the position of the stub 11 is not always effective for the heat treatment of all the objects 1 to be heated.

Therefore, here, the stub 11 is arbitrarily movable by the stub drive circuit 12, and the optimum position of the stub 11 is calculated according to the shape and size of the article 1 to be heated. As a method, the calculation unit 131 produces a plurality of types of models in which the positions of the stubs 11 installed in the waveguide 2 are changed.

Each of these models is analyzed as follows. In other words, numerical analysis is performed for a certain fixed step as described above, the pointing vector of the cross section inside the waveguide 2 is monitored, and a waveguide model without a reflected wave is analyzed for various stub positions in advance. Is used to separate the traveling wave and the reflected wave in the model with the object 1 to be heated.
The position of the stub 11 in the model with the least reflected waves obtained in this way is derived, and the position of the stub 11 at the beginning of heating is determined. Therefore, even with a small load, the number of reflected waves is reduced, and the load on the magnetron 3 is reduced.

By performing the analysis at the same time as the analysis in which the position of the stub 11 is made movable, the increase / decrease of the reflected wave with respect to the magnetic field can be easily calculated. At this time, it is assumed that the analysis is performed while also changing the relative dielectric constant that changes with the temperature rise of the object 1 to be heated. The optimum position of the stub 11 is calculated from the characteristics of the reflected wave with respect to the time obtained in this manner, and while the position of the stub 11 is changed with time, the state of the reflected wave is always small and efficient heating is possible. Becomes

As described above, an analysis error may occur depending on the accuracy of model creation. Therefore, position control of stub 11 is performed to avoid this. That is, the arithmetic unit 131 measures the surface temperature distribution of the object to be heated 1 by the temperature sensor 7 during heating, calculates the relative dielectric constant of the object to be heated, and performs the relative dielectric constant obtained at the time of the numerical analysis again. Is reflected in each cell of the model as a physical property value, thereby enabling more accurate position control of the stub 11.

As described above, by inputting the relative dielectric constant of the article to be heated 1 during heating and re-analyzing it and correcting the heating sequence based on the result, heating failure is prevented.

Further, even during the heating, the reflected wave is always suppressed to the minimum amount, and the heating time can be shortened.

Further, the influence of the analysis accuracy is reduced, and the position of the stub 11 can be controlled with high accuracy.

(Embodiment 4) The above-mentioned microwave oven may be configured as follows.

That is, after the user presses a heating start button (not shown) of the input unit 15, the state of the article 1 to be heated previously placed on the turntable 4 is confirmed by the image sensor 6 installed in the upper part of the refrigerator. Is done. At this time, the operation unit 13
1 indicates a no-load state when it is determined that the user has forgotten to place the article to be heated 1 on the turntable 4 based on an output signal of the image sensor 6 input via the processing unit 132. In order to prevent the microwave oven from being heated, the user may be notified of a warning sound via the output unit 16 or may output a message to that effect by voice. In addition, when it is determined that the object to be heated 1 contains a metal, the user may be notified in the same manner in order to avoid a danger such as discharge. In this way, it is possible to effectively avoid danger such as heating without load and metal discharge during heating.

(Embodiment 5) The above-mentioned microwave oven may be configured as follows.

That is, cooking procedures, various messages, and the like are displayed on an operation unit corresponding to the input unit 15 of the microwave oven or on a liquid crystal panel provided on the front surface of the microwave oven in the output unit 16. At this time, the temperature distribution-time characteristics of the inside or the surface of the heated object 1 obtained by performing the electromagnetic wave analysis in the microwave oven including the heated object 1 before the heating is displayed on the output unit 16 as the actual heating proceeds. I do. By doing so, the user can see at a glance the current heating condition inside the object to be heated 1 and operate the key of the input unit 15 to perform heating when the temperature desired by the user is reached. It can also be forcibly stopped (interrupted).

Further, a liquid crystal panel such as an LCD provided in the output section 16 is configured with a built-in memory, and this liquid crystal panel can be removed. Or the communication unit 135
The analysis result is transmitted to various types of information terminals including the portable type via the. By doing in this way, even at a position away from the position of the microwave oven, the current heating state of the inside of the heated object 1 may be monitored.

As described above, the heating condition can be checked at a glance, and the heating operation can be stopped at the temperature desired by the user.

(Embodiment 6) The above-mentioned microwave oven may be configured as follows.

For example, when both the rice and the side dish are heated on the turntable 4 at the same time, different users have different desires for how to finish the heating. Therefore, using the position and angle of the reflector 5 in advance, a plurality of patterns of the simulation result of the analyzed finish are displayed on the liquid crystal panel of the output unit 16 to select a desired finish result for the user. get. By doing so, it is possible to select a heating sequence according to the user's request such as a better side dish or a better rice side and perform a heating operation according to the sequence. Therefore, the user can select his / her favorite finish state before heating and perform the heating operation so as to achieve the selected finish state.

The embodiments disclosed this time are to be considered in all respects as illustrative 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.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of hardware of a microwave oven according to each embodiment of the present invention.

FIG. 2 is a functional configuration diagram of a microwave oven according to each embodiment of the present invention.

FIGS. 3A and 3B are flowcharts of a heating process according to each embodiment of the present invention.

FIG. 4 is a configuration diagram of an image sensor according to each embodiment of the present invention.

FIGS. 5A to 5C are diagrams illustrating a procedure for forming a mesh in the FDTD method.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 object to be heated, 2 waveguide, 3 magnetron, 4 turntable, 5 reflector, 6 image sensor, 7 temperature sensor, 8 reflector drive circuit, 9 shape recognition sensor, 1
0 shape recognition sensor drive unit, 11 stub, 12 stub drive circuit, 13 microcomputer.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 6/70 H05B 6/70 C 6/74 6/74 FF Term (Reference) 3K086 AA01 BB08 CA20 CB05 CC01 CC11 CD02 CD11 DA02 3K090 AA01 AB02 BA01 BB01 CA01 DA15 EA01 3L086 AA01 BB09 CA07 CB01 CB20 CC08 CC12 CC14 CC16 DA12 DA29

Claims (13)

[Claims] 1. A heating sequence applied for heating and cooking an object to be heated housed in a heating chamber with high frequency is calculated using an electromagnetic field model for the heating chamber in which the object to be heated is housed. A high-frequency heating / cooking apparatus, comprising: a rotating unit configured to rotate the object to be heated accommodated in the heating chamber; and a shape of the object to be heated provided in the heating chamber and accommodated in the heating chamber. A shape sensor for recognition, and for the heating chamber containing the object to be heated, using the information including shape information indicating the shape of the object to be heated based on the recognition result of the shape sensor, the electromagnetic field model The electromagnetic field model created by the model creating unit to be created and the model creating unit is assigned numerical value analysis processing by assigning physical property value information indicating a value of a physical property of the object to be heated. Analysis means for calculating a heating sequence, wherein the shape information indicates the shape of the object to be heated detected by the shape sensor while rotating the object to be heated by the rotating means, high frequency Cooking device. 2. The heating apparatus according to claim 1, wherein the shape sensor is movably provided in the heating chamber.
The high-frequency heating and cooking device according to item 1. 3. The high-frequency heating apparatus according to claim 1, wherein a plurality of the shape sensors are provided in the heating chamber. 4. An image sensor provided in the heating chamber for recognizing an image of the object to be heated housed in the heating chamber, and a plurality of different types of image information of the object to be heated. A memory unit in which the corresponding physical property value information is stored in advance, the memory unit corresponding to the object to be heated from the memory unit based on information of an image of the object to be heated according to the recognition result of the image sensor. The high frequency heating cooking device according to any one of claims 1 to 3, wherein the physical property value information is read. 5. The high-frequency heating and cooking apparatus according to claim 1, wherein the analysis unit repeats the numerical analysis process during the heating and cooking. 6. When the electromagnetic field model has symmetry with respect to a boundary, the analysis means performs the numerical analysis process on one part of the electromagnetic field model that is symmetric with respect to the boundary. The high-frequency heating cooking device according to any one of claims 1 to 5, characterized in that: 7. The high-frequency wave according to claim 1, wherein the electromagnetic field model comprises a hexahedral orthogonal lattice, and the lattice corresponding to the object to be heated is subdivided. Cooking device. 8. A heating apparatus further comprising: a temperature sensor provided in the heating chamber for detecting a temperature of the object to be heated housed in the heating chamber, wherein the analyzing means comprises: the temperature sensor during the heating cooking. The high-frequency heating cooking device according to any one of claims 1 to 7, wherein the physical property value information is re-assigned based on the detection result, and the numerical value analysis process is executed. 9. The heating chamber further includes a reflecting plate movably provided to reflect the high frequency, wherein a position and an angle of the reflecting plate are adjusted based on a result of the numerical analysis by the analysis unit. The high-frequency heating cooking device according to any one of claims 1 to 8, characterized in that: 10. A waveguide having a built-in stub for suppressing a reflected wave with respect to the high-frequency traveling wave for supplying the high-frequency wave into the heating chamber, wherein the stub is freely movable. The high-frequency heating and cooking apparatus according to any one of claims 1 to 9, wherein a position of the stub is adjusted based on a result of the numerical analysis performed by the analysis unit. 11. The apparatus according to claim 4, wherein a state of the object to be heated in the heating chamber is notified based on the image information of the object to be heated according to a recognition result of the image sensor. The high-frequency heating and cooking device according to any one of claims 10 to 10. 12. An apparatus according to claim 11, further comprising an input unit for inputting information relating to the heating cooking, wherein during the heating cooking, a result of the numerical analysis processing by the analysis unit according to the progress of the heating cooking is output. The high frequency heating cooking device according to any one of claims 1 to 11, characterized in that: 13. A finish state output means for outputting a finish state of the object to be heated based on each of the plurality of types of heating sequences obtained by the analysis means, wherein the finish state output means outputs the finish state. The high-frequency heating according to any one of claims 1 to 11, wherein the heating sequence corresponding to a desired type of the finishing state among a plurality of types of the finishing state is applied to the heating cooking. Cooking equipment.