JPH09102390A - Microwave oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heat a material to be heated so as to have a desired temperature distribution, by controlling a stop position of a rotary antenna because temperature of the material to be heated can be arbitrarily changed according to the stop position of the rotary antenna when it is stopped during heating. SOLUTION: Stopping a rotary antenna during heating is effective in a menu wherein unevenly finished temperature of a frozen lunch or the like is desired. A heating pattern is thus changed by changing variously a stop position of a lower rotary antenna 7. A relationship between the stop position of the antenna 7 and the heating pattern is found by means of an experiment. Stop positions of the antenna are previously memorized corresponding to numerals 1 to 10 in a ROM of a microcomputer. A user stopping the antenna 7 at an arbitrary angle according to a manual, can get a desired heating pattern. Otherwise, heating patterns are stored corresponding to stop positions of the antenna in a ROM of a microcomputer, the stop positions of the rotary antenna and the heating patterns being displayed on a display tube, a desired stop position of the rotary antenna is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a microwave oven for heating and controlling an object to be heated by radiating a microwave guided from a waveguide by a rotating antenna.

[0002]

2. Description of the Related Art Heretofore, a microwave oven of a rotating waveguide antenna (hereinafter referred to as a rotating antenna) system has been disclosed as a method for uniformly feeding electric waves emitted from a magnetron into a heating chamber (Japanese Patent Application Laid-Open No. 3-173094). Issue).

FIG. 11 is a schematic block diagram showing an example of a conventional microwave oven. The microwave oscillated by the magnetron 101 propagates through the waveguide 102. The propagating radio wave is radiated from the waveguide 102 into the heating chamber 104 by the rotating antenna 103 to heat and cook the object to be heated. Rotating antenna 10
3 is rotated by an antenna motor 105 arranged outside the waveguide 102.

The rotating antenna 103 is connected to an antenna motor 105 via a rotating antenna shaft 106 made of metal and a motor shaft 107 made of non-metal. As shown in FIGS. 12A and 12B, the rotary antenna 103 is
It is made of a metal plate such as aluminum, and its external shape is often rectangular or fan-shaped. In particular, as shown in FIG. 3B, both sides of the fan-shaped rotating antenna 103 are provided with bent portions 103a so as to reduce the impedance of the rotating antenna 103. By rotating the rotating antenna 103, microwaves in the heating chamber 104 are agitated and radiated to uniformly heat the object 109 to be heated on the tray 108.

Further, by the detection means 110 such as a weight sensor, an electric field sensor, a temperature sensor, a directional coupler,
There is disclosed a microwave oven in which a stub, a metal reflector, or a matching antenna is moved to perform impedance control to maximize the electric field strength in the heating chamber, and heating control is performed according to the amount and type of the object to be heated 109 (Japanese Patent Laid-Open No. 6-29242). -1131932 and JP-A-7-78681). There is also disclosed a microwave oven capable of controlling the rotational position of the rotary antenna 103 (Japanese Patent Laid-Open No. 5-144564).

As described above, a similar microwave oven has been disclosed which uniformly heats an object to be heated not only with one power supply port but also with a plurality of power supply ports by switching or converting the transmission line ( JP-A-63-195994, JP-A-2
-41160).

In addition to the method of controlling the rotating antenna and the metal reflector by using the detecting means, there is also disclosed a microwave oven in which the impedance is set so as to be finished uniformly according to a specific menu on the operation panel (Japanese Patent Laid-Open Publication No. Sho. 60-
240092). This is such that when the microcomputer operates a specific menu key, impedance control is performed based on data for the specific menu stored in advance in the ROM.

Generally, a commercial microwave oven is required to have a high output, and therefore has two or more magnetrons. The two-tube type is widely used (two magnetrons). In commercial microwave ovens, products in which the user can freely input the heating time and the heating output according to the heating purpose of the user from the outside and store the contents of the heating are popular.
Even if the operability is a little troublesome for commercial use, by repeatedly using the same menu under constant heating conditions,
It is best for the user to select and determine the optimum heating conditions according to the menu. Therefore, the user is set so that optimum heating can be performed only by pressing a menu key in which such a heating condition is preset and stored by the user.

It is assumed that the operation panel has memory keys "1" to "10" so that heating time and output corresponding to ten menus can be stored. As for the setting method, for example, in order to set a predetermined heating time (for example, 1 minute and 30 seconds) to the memory key “1”, a predetermined key may be input according to the flowchart shown in FIG. "Set" → "1" → "Clock" → "1" → "3" → "0" →
When you press the "Set" key, the memory key "1"
Is set to 1 minute and 30 seconds, which is stored in the non-volatile memory 16.

The same applies to stage heating. The method for setting the heating time and output over three stages (three stages) is shown in FIG.
Is shown in By doing so, the microwave output and the heating time can be appropriately changed in stages, and delicate cooking such as thawing and heating can be performed. The key operation is basically the same as that of FIG. 13, for example, “set” → “1” is input, and the first stage performs “clock” key → time input → “output” key → output input. Further, similarly, the second stage and the third stage are set, and finally the "set" key is used to finish. For example,
The first stage heats with a weak output, the second stage heats a little stronger than the first stage, and the third stage last heats with full power all at once. Various heating according to various menus can be freely combined. .

In a household microwave oven, milk, liquor syrup, vegetable preparation, rice, side dishes, etc., which are often used in everyday households, are categorized into menus and provided as dedicated keys on the operation panel. On the other hand, most commercial microwave ovens do not have a dedicated key as described above, and the user can freely input the heating time and the heating output according to the heating purpose of the user from the outside. However, due to changes in the social environment such as labor saving and simplicity, those that can freeze and heat frozen bento boxes and specific menus are beginning to spread.

[0012]

In the conventional household and commercial microwave ovens, it has been a problem how to finish the object to be heated to a uniform temperature. Therefore, a measure to improve this uniform heating is to move the stub, metal reflector, or rotating antenna to control the impedance to maximize the electric field strength in the heating chamber or to make it uniform according to the amount and type of the object to be heated. The heating was controlled so that there was no uneven heating.

Recently, a wide variety of foods can be frozen due to the advancement of freezing technology, and frozen lunch boxes such as the Makunouchi lunch box have begun to be mass-produced. Makunouchi bento, rice, pickles,
Salad, seasonings such as soy sauce filled in tubes, and side dishes are put in one plastic container. In addition, there are many types of bento, and the types of side dishes (salmon, hamburger, tempura, stewed foods, etc.) and their arrangement are also diverse to meet the needs of consumers.

Therefore, the frozen bento box described above,
Since various foods are mixed, there is a problem in heating them uniformly. That is, salads, pickles, seasonings, etc. can be cold,
A finishing temperature of 90 ° C or higher is desired for rice and the like. Thus, the desired temperature distribution in one container is wide, and it has been a problem that each food product is finished at the same and uniform temperature as in the conventional case.

An object of the present invention is to provide a microwave oven capable of heating an object to be heated with a desired temperature distribution by controlling the stop position of the rotary antenna.

[0016]

According to a first aspect of the present invention, there is provided a heating chamber for containing an object to be heated, a magnetron for generating microwaves, a waveguide for coupling the heating chamber and the magnetron, and the waveguide. In order to radiate the microwave guided to the tube with stirring into the heating chamber, a rotating antenna placed near the power supply port,
A position detection sensor for detecting the position of the rotating antenna,
A heating pattern storing means for storing a heating pattern showing a temperature distribution of the object to be heated corresponding to the stop position of the rotating antenna, and the rotating antenna at a position where a desired heating pattern is obtained based on a signal of the position detection sensor. A microwave oven, comprising: a control unit that controls to stop the microwave oven.

According to a second aspect of the present invention, there is provided the microwave oven according to the first aspect, wherein the input means for inputting a stop position of the rotary antenna at which a desired heating pattern is obtained, and the rotary antenna input by the input means. Stop data storage means for storing a stop position, and the control means stops the rotary antenna at the stop position stored in the stop data storage means.

A third aspect of the present invention is the microwave oven according to the second aspect, wherein the input means can also input the stop time of the rotary antenna, and the stop data storage means stops the rotary antenna. Time is also stored, and the control means controls the rotating antenna according to the stop position and the stop time stored in the stop data storage means.

According to a fourth aspect of the present invention, there is provided a heating chamber for containing an object to be heated, a magnetron for generating a microwave, a waveguide for coupling the heating chamber and the magnetron, and a microwave guided to the waveguide. A rotary antenna disposed near a power supply port for radiating the rotary antenna, a position detection sensor for detecting the position of the rotary antenna, and a heating pattern showing the temperature distribution of the object to be heated corresponding to the stop position of the rotary antenna. Heating pattern storage means for storing, input means for selecting the heating pattern, temperature detecting means for measuring the surface temperature of the object to be heated at multiple points, and the object to be heated indicated by the heating pattern selected by the input means While confirming the temperature distribution by the signal from the temperature detecting means so that the temperature distribution becomes, the stop position and stop time of the rotary antenna are controlled based on the signal of the position detection sensor. A microwave oven, characterized in that it comprises a control means.

According to a fifth aspect of the present invention, there is provided the microwave oven according to the second, third or fourth aspect, wherein the rotary antennas are arranged at a plurality of power supply ports, and the control means stops one rotary antenna. The other rotating antenna is controlled to rotate.

A sixth aspect of the present invention is the microwave oven according to the second, third or fourth aspect, wherein the position detection sensor is an optical sensor including a light emitting element and a light receiving element and is provided on a wall of the heating chamber. It is placed outside the heating chamber at a position close to the small hole that has been penetrated, and a transparent film is attached to the small hole from the inside of the heating chamber. The locus corresponds to a small hole for detecting an optical sensor provided on the wall of the heating chamber, and the hole position of the rotary antenna is provided at a position eccentric to the center line of the rotary antenna.

According to a seventh aspect of the present invention, in the microwave oven according to the second or third aspect, the stop data is set when inputting the stop position of the rotary antenna and when heating including the stop operation of the rotary antenna. It is characterized by comprising display means for displaying the stop position of the rotary antenna stored in the storage means.

The invention according to claim 8 is the microwave oven according to claim 2, 3 or 4, wherein the microwave oven is rotated when inputting the stop position of the rotary antenna and when heating including the stop operation of the rotary antenna. Display means for displaying the heating pattern of the object to be heated stored in the heating pattern storage means corresponding to the antenna stop position is provided.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a microwave oven according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an embodiment of a two-tube type commercial microwave oven according to the present invention. FIG. 1A is a configuration diagram viewed from the side,
FIG. 3B is a configuration diagram viewed from the top.

The microwave oven according to the present embodiment is connected to the heating chamber 1, the upper magnetron 2, the lower magnetron 3, and the upper magnetron 2 and is connected to the upper waveguide 4 and the lower magnetron 3 arranged above the heating chamber 1. Then, the lower waveguide 5 arranged at the lower part of the heating chamber 1, the upper rotating antenna 6 arranged at the feeding port of the upper waveguide 4, the lower rotating antenna 7 arranged at the feeding port of the lower waveguide 5, and the upper rotation. An upper antenna motor 10 that drives the antenna 6 through the upper rotating antenna shaft 8, a lower antenna motor 11 that drives the lower rotating antenna 7 through the lower rotating antenna shaft 9, a splash cover 12, and a tray 13 on which an object to be heated is mounted. It is composed of the bottom plate 14 of the heating chamber 1.

The bottom plate 14 of the heating chamber 1 has a small hole 14a for detecting the position of the lower rotary antenna 7. A transparent film 15 is attached to the heating chamber side of the bottom plate 14 so as to cover the small holes 14a. Further, an optical sensor 16 is arranged outside the heating chamber facing the small hole 14a. The optical sensor 16 is a photocoupler including a light emitting element and a light receiving element.

The lower rotary antenna 7 is made of metal such as aluminum and has a substantially fan shape. Lower rotating antenna 7
Has bent portions 7a formed on both sides thereof, and when it is rotated about the lower rotating antenna shaft 9, the detecting hole 7b is located at a position overlapping the small hole 14a and eccentric to the center line of the rotating antenna. Are formed.

FIG. 2 shows a schematic circuit diagram of the microwave oven. FIG. 1A is a circuit diagram of the entire microwave oven,
FIG. 1B is a circuit diagram around the control device. Upper magnetron 2, lower magnetron 3, upper antenna motor 10,
The lower antenna motor 11 includes relays R ₁ , R ₂ and R, respectively.
It is turned on / off by ₃ and R ₄ . Relays R ₁ , R ₂ ,
R ₃ and R ₄ are controlled by the controller 17. The control device 17 is specifically configured by a microcomputer (hereinafter abbreviated as a microcomputer) 21 shown in FIG. And this microcomputer 21 is a transistor Tr
Relays R ₁ , R ₂ , through ₁ , Tr ₂ , Tr ₃ , Tr ₄
Controls R ₃ and R ₄ . The control condition is input to the microcomputer 21 from the operation panel 22, and the control condition is stored in the non-volatile memory 23. Control is performed based on the signal from the optical sensor 16 that detects the position of the lower rotary antenna 7 and the conditions stored in the nonvolatile memory 23. The optical sensor 16 includes a light emitting element 16a and a light receiving element 16b, and the operation panel 22
Is the display tube 24, memory key 25, "heat" key 2
6, "Time" key 27, "Set" key 28, "Cancel"
It comprises a key 29 and an "output" key 30. Microcomputer 21
Sends a signal to the base of the transistor Tr ₅ to control the light emission of the light emitting element 16a connected to the emitter. The microcomputer 21 detects the position of the lower rotary antenna 7 from the light receiving signal from the light receiving element 16b. Here, in order to apply a constant voltage to the light receiving element 16b, a resistor R having one end connected to the collector of the transistor Tr ₅ is connected in series.

The microwave oven described in the conventional example has one magnetron, but in the present embodiment, microwaves are supplied from above and below the heating chamber 1. In the case of heating by the normal menu, the upper and lower antenna motors 10 and 11 operate and the vertical rotating antennas 6 and 7 continue to rotate during heating. The object to be heated 18 is heated uniformly by rotating the upper and lower antennas 6 and 7 during heating.

However, it has been found that it is effective to stop the rotating antenna during heating in a menu such as a frozen bento box where a non-uniform finish temperature is desired. FIG. 3 shows experimental data in which the lower rotary antenna 7 is stopped and heated.
Depending on the position where the lower rotation antenna 7 stops rotating, the tray 1
The temperature of each part of 3 is measured. Water to be heated 1
00cc, heating time 30 seconds, commercial microwave oven 1500
Heated at W output. If the lower rotary antenna 7 is stopped at a position 30 degrees from the front, a heating pattern is shown in which the central position of the tray 13 is strong and the peripheral part thereof is weak. When the lower rotary antenna 7 is stopped at a position 180 degrees from the front, a heating pattern is shown in which the left and right ends of the center of the tray 13 are strong and the upper and lower ends of the center are weak. In this way, by changing the stop position of the lower rotary antenna 7 variously, the heating pattern also changes. The relationship between the stop position of the lower rotary antenna 7 and the heating pattern is previously obtained by an experiment.

Therefore, as shown in FIG. 4, the antenna stop position is previously stored in the ROM of the microcomputer 21 in correspondence with the numeral 1 → 10.
Is stored in The user is informed in advance by a manual or the like of the heating pattern such as which number on the tray 13 is to be heated and which is heated by the user. The user can obtain the desired heating pattern by stopping the lower rotary antenna 7 at an arbitrary angle from the outside according to this manual. Alternatively, the heating pattern corresponding to the stop position of the rotating antenna is stored in the ROM of the microcomputer 21 or the like, the stop position of the rotating antenna and the heating pattern are displayed on the display tube, and the desired stop position of the rotating antenna is selected. .

Therefore, when the food is placed in different places such as a frozen bento, the rotating antenna stop position is set by the user so that the place where the salad or pickle is weak is weak and the rice is strong. ) Will be selected.

An operation method for storing the antenna stop position in the memory key 25 is shown in the flowchart of FIG. Press the "Set" key 28 to enter the input mode (step S
1), press the memory key "1" (step S2),
A predetermined heating time is input from the "clock" key 27, and the "set" key 28 is pressed to store it in the memory number "1" (steps S4 and S5). The "set" key 28 is input again to enter the input mode (step S6), and the "number" key 25 is input to select the number corresponding to the heating pattern (steps S6 and S7). For example, if the antenna stop position is 30 degrees, 1 is input. In this way, a more delicate finish is possible when the antenna stop time can be changed than when the antenna is stopped during heating.

Next, the "heat" key 26 is pressed and the antenna stop time is entered from the "number" key 25 (step S
8, S9). Finally, when the "set" key 28 is pressed, the process is completed and the stop position and stop time of the rotary antenna are stored in the non-volatile memory 23 (step S10). here,
Only the heating of one stage has been described, but in the heating of the second and third stages as well, the stop position and stop time of the rotary antenna are input after the heating time and the output.

When actually heating and cooking, the memory 25
When the number (which becomes the key number) is pressed, heating is started with the heating time, heating output pattern, rotary antenna stop position, and stop time stored in the non-volatile memory 23. You can start heating with one touch, or press the number and then "heat"
Either heating may be started with the key 26.

[0036] As the relay R ₁ to R ₄ is turns ON, the signal is sent from the microcomputer 21 to the transistor Tr ₁ to Tr _4.
Microwaves oscillate from the upper and lower magnetrons 2 and 3, and the upper and lower antenna motors 10 and 11 rotate. The microcomputer 21 fetches and controls the data corresponding to the pressed "number" key 25 from the nonvolatile memory 23.

FIG. 6 is a flow chart showing the control of the rotary antenna by reading the optical sensor output pulse.
After a certain time has elapsed since the antenna motor 11 was rotated after the heating was started (steps S11 and S12), a signal for turning on the light emitting element 16a is sent from the microcomputer 21 (step S13). Here, a certain time is actually several seconds, and a signal for turning on the light emitting element 16a means a high-level signal sent to the base of the transistor Tr ₅ . The light emitted from the light emitting element 16a passes through the small hole 14a and is irradiated into the heating chamber 1. If the lower rotating antenna 7 is present here, the light is reflected and reaches the light receiving element 16b, and the light receiving element 16b is turned on. Without the lower rotating antenna 7, the light is not reflected by the light receiving element 16b, so the output is OFF. The light receiving element 16b is connected in series with a resistor R, and a DC voltage V is applied to it. The output voltage of the light receiving element 16b is read by the microcomputer 21 as a signal.

The waveform of the output pulse read is shown in FIG. When the voltage of the output pulse is V, the lower rotating antenna 7
It just rotates on the small hole 14a. Midway of output waveform T
There is a timing at which the voltage drops to 0 when 1 hour has passed. This shows the case where the detection small hole 7b opened in the lower rotary antenna 7 has passed. This is because the small hole for detection 7b does not reflect light. When the detection eyelet 7b passes, a pulse is again generated for T2 time. And the rotating antenna 7
When is rotated once (T3 time), an output pulse appears again.

Since the lower rotary antenna 7 has the bent portion 7a, the light passing through the small hole 14a is bent by the bent portion 7a.
In FIG.
As shown in (B), noise occurs in the pulse waveform. Therefore, the fan-shaped portion (the dotted line portion in FIG. 1) where the lower rotary antenna 7 reflects light has a flat surface without the bent portion 7a.

The time T1, T2, T3 is set by the microcomputer 21.
Reads the time (steps S15 and S16), and when T1 is larger than T2, it is determined that the lower rotating antenna 7 is rotating to the right, and conversely, it is rotating to the left (steps S17, S18,
19). If the rotation direction of the antenna motors 10 and 11 is constant, the detection small hole 7a is not necessary, but when the rotation direction is not constant, if the rotation direction is unknown, the lower rotation antenna 7 can be accurately set to a predetermined stop position. Since it cannot be stopped, the detection small hole 7a is necessary.

The microcomputer 14 retrieves the data corresponding to the numeral keys of the memory 18 stored in the nonvolatile memory 16. If the extracted angle is 30 degrees, (30/36
0) × T3 = T3 / 12 At the position of time, turn on the relay R1
FF is performed and the lower antenna motor 11 is stopped (step S2).
0). In case of reverse rotation, (11/12) × T3 in OF
F The microcomputer 21 accumulates the OFF time of the relay R ₁ . When this time exceeds the rotating antenna stop time stored in the non-volatile memory 23, the relay R ₁ is turned on again.

Although the heating is performed for the heating time set in this way, if the stage heating is performed, the heating is continued similarly to the 2nd and 3rd stages even after the 1st stage heating is completed. During this heating, the lower antenna motor 11 is temporarily stopped, but the upper antenna motor 10 continues to rotate. The lower rotating antenna 7 arranged at the bottom of the tray 13 is the tray 1
Since it is close to the object to be heated 18 placed on No. 3,
Has a large effect on. In order to obtain a distinctive heating pattern, it is more effective to stop the lower rotating antenna 7 than to stop the upper rotating antenna 6, the strength of the heating pattern can be made more conspicuous, and the heated object in which foodstuffs with a wide temperature range are mixed It is also possible to deal with.

In the above description, the lower rotary antenna 7 has a fan shape, but since it has a large surface area and has the bent portion 7b, the impedance is low and the degree of microwave coupling is smaller than that of the upper rotary antenna 6. Depending on the cooking menu, when an extreme heating pattern is desired, it is desired that the lower rotary antenna 7 has an antenna structure with a higher degree of coupling and higher impedance than the upper rotary antenna 6.

When the upper and lower rotating antennas 6 and 7 are stopped and heated, the heating characteristics show a significantly nonuniform heating pattern.
If heated in such a state, a component forming the heating chamber 1, for example, a plastic splash cover 12 disposed below the upper rotary antenna 6 is locally heated, or a device malfunctions. Therefore, the upper rotating antenna 6
Keeps the relay R ₂ turned on so that it always rotates.

Although the above description is of the system using the vertical rotating antenna, as shown in FIG. 8, if the system uses only the upper rotating antenna 6, the upper rotating antenna 6 can be controlled in the same position as described above. The object to be heated on the turntable 31 rotated by the motor 32 can be heated with a desired temperature distribution.

On the operation panel 22, in addition to the keys, a display tube 24
Is also provided. The heating time and the output are displayed on the display tube 24. An example in which the stop positions of the rotary antennas 6 and 7 are displayed on the display tube 24 in correspondence with the actual rotary antennas 6 and 7 is shown in FIG. You can use the Japanese characters on the display tube 24,
You may prepare a special display segment. By displaying the approximate stop position where the rotating antenna stops when setting the stop position or during heating, you can more visually represent the operation mistake or operation.

Although the method of directly displaying the stop position of the rotary antenna has been described above, it is more intuitive for the user to visually display the heating pattern generated by the stop. An example of displaying it is shown in FIG. By turning on the segment of the numeric day character, the tray 13
Shows which part of the well is heated. In other examples, it is also possible to display the light amount of the lighting segment, or to display the heating pattern by utilizing the color change of cold color and warm color using a multicolor LED. These displays are processed by the microcomputer 21 based on individual data.

In the unlikely event that the antenna motors 10 and 11 do not rotate, the output pulse of the light receiving element 16b is not generated and the microcomputer 21 cannot read the pulse waveform data T1, T2 and T3. Therefore, for a certain time (for example, the time of 3 rotations =
When there is no data even after 3 × T3) has passed, it is judged to be abnormal and a buzzer is sounded or a warning is displayed on the display tube 23. In addition, safety can be secured by turning off relays R3 and R4 and stopping heating.

In this description, the method of inputting the rotating antenna stop position from the outside has been described. However, a microwave oven in which a heating pattern is input from an input means that is displayed in a menu in advance and then automatically controlled is also conceivable.
Various heating patterns are stored in the storage device, which are selectively set on the operation panel. Temperature detecting means such as a temperature sensor is installed in the heating chamber to detect the surface temperature of the object to be heated. Based on the data, the microcomputer stops and controls the rotating antenna so that the heating pattern shows the temperature distribution of the object to be heated according to the menu. In this way, the control is automatically performed without the need to input the stop position, stop time, etc. from the outside. Naturally, the control of the rotating antenna and the display function of the heating pattern by the display tube of the operation panel are the same as those described above.

[0050]

According to the invention of claim 1, the rotating antenna is stopped during heating, and the temperature distribution of the object to be heated by heating can be arbitrarily changed by the stop position, so that uniform heating can be achieved as in the conventional case. Instead, the heating pattern showing the temperature distribution can be arbitrarily controlled according to the object to be heated.

According to the second aspect of the present invention, the stop position of the rotary antenna can be arbitrarily set by the input means, so that the heating pattern can be heated according to the user's preference.

According to the invention of claim 3, by controlling the stop position and stop time of the rotary antenna by the input means,
The object to be heated can have a more delicate finish, and the accuracy of temperature distribution due to heating can be improved.

According to the fourth aspect of the present invention, the stored heating pattern is selected by the input means, and the temperature is detected by the signal from the temperature detecting means so that the temperature distribution of the object to be heated indicated by the heating pattern is obtained. Since the stop position and stop time of the rotary antenna are controlled while confirming the distribution, the user only needs to select and set the heating pattern, and thereafter the heating is automatically controlled, which simplifies the operation.

According to the fifth aspect of the invention, the rotating antennas are controlled so that the rotating antennas are always rotating so that the plurality of rotating antennas do not stop at the same time. Since microwaves are radiated, local overheating in the heating chamber can be prevented and safety is improved.

According to the sixth aspect of the present invention, the position detecting sensor is composed of the optical sensor, so that the mounting structure and the detecting speed can be increased, the antenna motor can be accurately controlled, and the detection for the optical sensor can be performed. Since the film is attached to the small holes, water vapor and water droplets generated from the object to be heated do not enter, and the reliability is improved. And
The rotating antenna has a hole for antenna position detection penetrating therethrough, and the rotation locus of the hole corresponds to a small hole for detecting an optical sensor arranged on the wall of the heating chamber, and the hole position of the rotating antenna corresponds to the center line of the rotating antenna. Since they are provided at asymmetrical positions, different pulse waveforms are generated depending on the rotating direction of the rotating antenna, and an inexpensive motor that rotates the antenna motor in both forward and reverse directions can be used.

According to the invention of claim 7, since the position where the rotary antenna stops is displayed on the display tube, the position of the rotary antenna can be visually confirmed, erroneous operation can be prevented, and operability is improved.

According to the eighth aspect of the present invention, since the heating pattern is displayed on the display tube, it is easy to know which place on the tray is heated well, and the heating pattern setting operability is improved.

[Brief description of the drawings]

1A and 1B are schematic configuration diagrams showing an embodiment of a microwave oven according to the present invention.

2A and 2B are schematic circuit diagrams including a control circuit of the microwave oven shown in FIG.

FIG. 3 is a display example of an antenna stop position and a heating pattern.

FIG. 4 is an explanatory diagram showing an example of a rotating antenna stop position corresponding to a numeric key and a heating pattern.

FIG. 5 is a flowchart showing a procedure for setting a memory using the operation panel.

FIG. 6 is a flowchart showing an operation of controlling a rotary antenna for reading an output pulse of an optical sensor.

7A to 7C are explanatory diagrams of output pulse waveforms of the optical sensor according to the present invention.

FIG. 8 is a schematic configuration diagram of a microwave oven with a turntable and a rotating antenna.

9A and 9B are display explanatory views showing a stop position of a rotating antenna.

FIG. 10 is a display explanatory view showing a temperature distribution according to a heating pattern.

FIG. 11 is a schematic configuration diagram showing an example of a conventional microwave oven.

12A and 12B are explanatory views showing a rotary antenna of a conventional microwave oven.

FIG. 13 is a flowchart showing a procedure for setting a memory using the operation panel of the conventional microwave oven.

FIG. 14 is a flowchart for setting a heating time and an output over three stages in a conventional microwave oven.

[Explanation of symbols]

 1 heating chamber 2 upper magnetron 3 lower magnetron 4 upper waveguide 5 lower waveguide 6 upper rotating antenna 7 lower rotating antenna 14a detection small hole 7a bent portion 7b detection hole 15 film 16 optical sensor (photocoupler) 16a light emitting element 16b light receiving Element 18 Object to be heated

Claims (8)

[Claims] 1. A heating chamber for containing an object to be heated, a magnetron for generating a microwave, a waveguide for coupling the heating chamber and the magnetron, and a microwave guided to the waveguide in the heating chamber. A rotary antenna arranged near the power supply port for stirring and radiating, a position detection sensor for detecting the position of the rotary antenna, and a heating pattern indicating the temperature distribution of the object to be heated corresponding to the stop position of the rotary antenna are stored. A microwave oven, comprising: a heating pattern storage means for controlling the rotating antenna; and a control means for controlling the rotating antenna so as to stop at a position where a desired heating pattern is obtained based on a signal from the position detection sensor. 2. The control device further comprises: input means for inputting a stop position of the rotary antenna at which a desired heating pattern is obtained; and stop data storage means for storing the stop position of the rotary antenna input from the input means. The microwave oven according to claim 1, wherein the means stops the rotary antenna at a stop position stored in the stop data storage means. 3. The input means can also input the stop time of the rotary antenna, the stop data storage means also stores the stop time of the rotary antenna, and the control means is the stop data storage means. The microwave oven according to claim 2, wherein the rotating antenna is controlled by the stop position and the stop time stored in the. 4. A heating chamber for accommodating an object to be heated, a magnetron for generating a microwave, a waveguide for coupling the heating chamber and the magnetron, and a microwave guided by the waveguide is radiated into the heating chamber. Rotating antenna arranged in the vicinity of the power feeding port, a position detection sensor for detecting the position of the rotating antenna, and a heating pattern memory for storing a heating pattern showing a temperature distribution of the object to be heated corresponding to the stop position of the rotating antenna. Means, input means for selecting the heating pattern, temperature detecting means for measuring the surface temperature of the heated object at multiple points, and temperature distribution of the heated object indicated by the heating pattern selected by the input means. As described above, while confirming the temperature distribution by the signal from the temperature detecting means, based on the signal from the position detecting sensor, the control means for controlling the stop position and the stop time of the rotating antenna, Microwave oven comprising: a. 5. The rotating antenna is arranged at a plurality of power supply ports, and the control means, when one rotating antenna is stopped,
The microwave oven according to claim 2, 3 or 4, wherein the other rotating antenna is controlled to rotate. 6. The position detecting sensor is an optical sensor composed of a light emitting element and a light receiving element, and is disposed outside the heating chamber at a position close to a small hole penetrating the heating chamber wall. Is attached a transparent film from the heating chamber, the rotating antenna, the hole for antenna position detection is penetrated, the rotation trajectory of the hole corresponds to the optical sensor detection small hole arranged on the heating chamber wall, the rotation The microwave oven according to claim 2, 3 or 4, wherein the hole position of the antenna is provided at a position eccentric to the center line of the rotating antenna. 7. A display means for displaying the stop position of the rotary antenna stored in the stop data storage means at the time of input setting of the stop position of the rotary antenna and at the time of heating including the stop operation of the rotary antenna. The microwave oven according to claim 2, wherein the microwave oven is a microwave oven. 8. The object to be heated stored in the heating pattern storage means corresponding to the rotating antenna stop position at the time of setting the input of the rotating antenna stop position and at the time of heating including the stopping operation of the rotating antenna. The microwave oven according to claim 2, further comprising display means for displaying a pattern.