Semiconductor Oscillation Microwave Oven

Abstract

To disclose a microwave oven capable of precisely heating a heated object utilizing features of a semiconductor oscillator.SOLUTION: On a bottom face of a heating chamber 2, for example, five antennas 9a-9e, for example, are disposed in a petal pattern. Temperature sensors 12 capable of detecting temperatures while the entire heating chamber 2 is divided into areas as many as the sensors are disposed on a top face of a casing 1. The temperature of an entire heated object W is raised while temperature nonuniformity is reduced by repeating steps of detecting a shape, a mass and the temperature nonuniformity of the heated object W in first heating (initial step), and detecting the temperature again after driving only the antennas 9a-9e in locations of low temperatures. Thus, the heated object W can be equally heated to a target temperature.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a microwave oven that uses a semiconductor to oscillate microwaves. [Background technology]

[0002] Magnetrons are generally used as the microwave generating means in microwave ovens, but magnetrons have problems such as poor heating directionality, large frequency variations, being heavy and bulky because they are made up of an iron core and coil, the need for a waveguide, turntable or antenna to improve heating performance makes the structure complicated, and they have a short lifespan.

[0003] For this reason, microwave ovens using semiconductor oscillators have been attracting attention, but conventional semiconductor oscillator microwave ovens have had the problem of difficulty in uniformly heating the object to the appropriate temperature due to differences in the material, shape, weight, etc. of the object. In other words, there are differences in the irradiation state of the radio waves and the state of the object (quality, shape, weight, etc.) depending on the part of the object, which creates differences in the microwave absorption rate and temperature rise, making it impossible to heat the object uniformly. For this reason, a phenomenon occurred in which part of the object was overheated while other parts were insufficiently heated.

[0004] As a means for solving this problem, a method of providing multiple antennas and irradiating microwaves simultaneously has been considered. Examples of this method are disclosed in Patent Documents 1 and 2.

[0005] In Patent Document 1, the heating portion is specified by detecting the color of the container with a color sensor, and therefore it can be said that heating can be performed in a well-balanced manner, for example, by not heating the salad in a lunch box. On the other hand, Patent Document 2 aims to prevent the backflow of microwaves from multiple oscillation antennas, and therefore it can be said that microwaves are simultaneously emitted from multiple oscillation antennas. Patent Document 1 can also be interpreted as driving multiple oscillation antennas simultaneously. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6486669 [Patent Document 2] JP 2020-155275 A Summary of the Invention [Problem to be solved by the invention]

[0007] Now, semiconductor microwave oscillators have the advantages of high directivity, stable frequency, light weight, long service life, and easy output change, but when multiple antennas are driven simultaneously, as is the problem discussed in Patent Document 2, the microwaves oscillated from each antenna interfere with each other, which often leads to a reduction in output and a decrease in uniformity of the oscillator element, making it difficult to perform proper heating. Therefore, practical application is very difficult.

[0008] The present invention has been made against the background of the above-mentioned circumstances, and aims to disclose a microwave oven which is excellent in quality and practicality while effectively utilizing the advantages of an oscillation method using a semiconductor element. [Means for solving the problem]

[0009] The present invention includes various configurations, which are specified in each claim. The semiconductor oscillator microwave oven of the invention of claim 1 is as follows: "Multiple semiconductor microwave oscillating antennas are arranged horizontally at different positions on the bottom or top of a heating chamber equipped with a door. I The microwave oscillation antennas are not driven simultaneously but one at a time. It is set as follows: Furthermore, a temperature sensor is provided for detecting the surface temperature of the object placed in the heating chamber at a plurality of positions. When it is determined that there is a temperature unevenness in the object, each of the microwave oscillation antennas is driven so as to raise the temperature to a preset temperature while correcting the temperature unevenness based on the temperature detected by the temperature sensor. " That basic It is structured as follows. The temperature sensor may be an infrared sensor or a thermoviewer.

[0010] The invention of claim 2 is Same basic configuration as In " Each of the microwave oscillating antennas can select from a plurality of outputs and drive times, and the drive sequence, output, and drive time of each of the microwave oscillating antennas are combined to control so as to reduce the temperature unevenness of the heated object. The structure is as follows. do.

[0011] The invention of claim 3 is 1 or 2 In "At least four microwave oscillating antennas are arranged, The temperature sensor is capable of detecting temperatures of the object to be heated divided into a number of areas, If it is determined that there is a temperature unevenness in the object to be heated, the microwave oscillation antenna located in the part with the lower temperature is driven once or multiple times, so that the temperature of the entire object to be heated is raised evenly to a predetermined temperature. The structure is as follows.

[0014] Claim 4 The invention is as follows: Either 1 to 3 Leave, "Multiple reference maps are created in which the output, drive time, and drive sequence of each microwave oscillating antenna are set in accordance with multiple reference patterns with different temperature unevenness, and when the temperature unevenness of the actual heated object is the same as or close to one of the reference patterns, each microwave oscillating antenna is driven based on the reference map corresponding to that reference pattern." The structure is as follows.

[0015] Claim 5 The invention is as follows: 1~3 In any of the following: "Parts of the heated object are controlled so as not to heat up." The structure is as follows.

[0016] Claim 6 The invention is as follows: 1~3 In any of the following: "The operation panel is equipped with an operation section that allows you to select the heating area." The structure is as follows. Effect of the Invention

[0017] In the present invention, multiple microwave oscillating antennas are not driven simultaneously, so there is no problem of microwaves interfering with each other. Therefore, it is possible to prevent oscillation from becoming unstable and achieve stable heating. In addition, since the microwave oscillating antennas are driven individually, it is possible to eliminate interference, improve heating efficiency, and contribute to shortening heating time. Furthermore, since only one of the multiple antennas is driven, only one semiconductor oscillator (oscillating element) is required. Therefore, it is possible to reduce costs and make the device lighter and more compact.

[0018] In addition, in the present invention, The surface temperature of the object to be heated is detected by a temperature sensor and the microwave oscillation antenna is controlled based on this temperature, so that various different types of objects to be heated can be heated (warmed) evenly and uniformly to the target temperature.

[0019] In particular, as in claim 3, it is preferable to arrange four or more microwave oscillating antennas and detect the temperature of the heated object by dividing it into a large number of areas (grids, addresses), which makes it possible to determine the heated object and heat it in detail.

[0020] As described above, there are various types of objects to be heated, and the way in which heat passes through the objects varies depending on how they are placed in the heating chamber. Therefore, it would be preferable to have a method that can heat objects uniformly even if the objects are of different types or how they are placed. 1 By adopting the configuration described above, the temperature unevenness that occurs in the object to be heated due to the initial heating is used as a reference and heating is performed so as to eliminate the unevenness, so that any type of object to be heated can be handled.

[0021] As mentioned above, one of the features of semiconductor microwaves is that the output can be easily adjusted, and in claim 5, this feature can be used to contribute to shortening the heating time and promoting uniformity of the temperature. In addition, adjusting the output and time separately is troublesome, but in claim 2 The output and drive time (heating time) can be set to multiple values, and any value can be selected for drive, making control easier.

[0022] In addition, since the way heat passes through the object varies depending on the object being heated, it is possible and preferable to store the temperature rise per unit time and unit power in relation to the unit time (e.g., 10 seconds or 15 seconds) and power, and control the drive time and power of each microwave oscillator antenna in response to the temperature unevenness (i.e., feedback control).

[0023] As a control mode for each microwave oscillation antenna, it is possible to set the output, driving time and driving sequence of each microwave oscillation antenna based on the temperature of the object to be heated. 4 By preparing a reference pattern as described above and selecting and controlling a pattern that matches the temperature unevenness after the initial process, there is an advantage in that the control method can be simplified.

[0024] There are times when you may wish to avoid heating some of the items to be heated, such as in a bento box that comes with salad or pickles. 5 This demand can be met by adopting the above configuration. In this case, as a means for identifying the non-heated area, a color sensor may be provided to identify the non-heated area from its color (green, yellow) as in Patent Document 1, or the non-heated area may be identified from, for example, a video or image of the object to be heated. 6 A semiconductor microwave oven allows users to heat food according to their preferences.

[0025] Now, the strength of microwaves is proportional to the output, but when the frequency (wavelength) changes, the reflection of microwaves in the heating chamber and the transparency to the heated object change, so by changing the microwave frequency, the area that is in the same heated state can be changed. In the present application, the semiconductor oscillator can change the frequency (wavelength) within the legal range (2400 to 2500 Hz), so by changing the frequency according to the size, arrangement, shape, etc. of the heated object, the microwave loss can be suppressed and the heated object can be heated efficiently. This can contribute to uniform heating and shortening the heating time.

[0026] Specifically, it is possible to select the optimal frequency by verifying through experiments how the heating area changes depending on the relationship between the size of the object to be heated and the frequency, and patterning the relationship between the temperature distribution of the object to be heated after initial heating at a reference frequency (e.g., 2450 Hz) and the frequency. Alternatively, if the temperature rise after initial heating at the reference frequency is not as expected, it is possible to select the optimal frequency by checking the degree of temperature rise by raising or lowering the frequency. It is also possible to provide a self-learning function that adds a map or modifies an existing map based on the actual data obtained in this way.

[0027] The frequency can be adjusted continuously within the legal range, but in reality, it is possible to choose from about three frequencies: 2400Hz, 2450Hz, and 2500Hz, and the control circuit can also be simplified. [Brief description of the drawings]

[0028] [Figure 1] 1 is a perspective view showing an example of the appearance of an embodiment of a semiconductor oscillator microwave oven. [Diagram 2] FIG. 1 is a rough cross-sectional plan view of a semiconductor oscillator microwave oven. [Diagram 3] FIG. 3 is a vertical cross-sectional view taken along line III-III in FIG. 2. [Figure 4] This is a table of specifications for microwave oscillator antennas. [Diagram 5] FIG. 1A is a diagram showing an example of a temperature detection area, and FIG. 1B is a diagram showing an example of a first heating state (initial step). [Figure 6] FIG. 2 is a diagram showing a basic mode of control. [Figure 7] FIG. 11 is a diagram showing a more specific control mode, where (A) is a diagram showing a first temperature distribution, and (B) is a diagram showing a second heating state. [Figure 8] FIG. 13(A) is a diagram showing the second temperature distribution, and FIG. 13(B) is a diagram showing the third heating state. [Figure 9] FIG. 11 is a cross-sectional plan view of a second embodiment. [Figure 10] FIG. 11 is a plan sectional view of a third embodiment. [Figure 11] FIG. 13 is a cross-sectional plan view of a fourth embodiment. [Figure 12] FIG. 13 is a plan sectional view of the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] (1) Structure of the First Embodiment Next, an embodiment of the present invention will be described with reference to the drawings. First, a first embodiment (basic embodiment) will be described with reference to Figs. 1 to 8. The basic structure of a microwave oven is the same as that of a conventional microwave oven, and as shown in Fig. 1, the microwave oven comprises a rectangular parallelepiped housing 1 with a square heating chamber (cooking chamber) 2 opening toward the front, and a horizontally pivotable door 3 disposed on the front of the housing 1 for opening and closing the heating chamber 2.

[0030] The front of the right side of the housing 1 is the operation unit 4. The left side of the door 3 is connected to the housing 1 via a hinge. The handle 5 is gate-shaped and protrudes forward, but the handle type is in a hollowed-out state. P As simply shown in Fig. 2, an electrical equipment chamber 6 in which electrical equipment is arranged and in which a heat dissipation section is provided is formed on the right side of the housing 1. In addition, a flat table 7 is fixed to the bottom surface of the heating chamber 2, which protects the antennas 9a to 9b and on which the object to be heated W is placed.

[0031] The housing 1 has a double structure except for its rear surface, and five antennas, numbered first to fifth, 9a to 9e that oscillate microwaves are arranged in a lower hollow portion 8. One of the five antennas 9a to 9e is located in the center of the heating chamber 2, and the other four are arranged in the corners of the heating chamber 2. Therefore, the five antennas 9a to 9e are arranged in a petal shape.

[0032] Of the five antennas 9a to 9e, the one located in the center will be referred to as the first antenna 9a, the one located at the rear left in Figure 2 will be referred to as the second antenna 9b, the one located at the rear right will be referred to as the third antenna 9c, the one located at the front right will be referred to as the fourth antenna 9d, and the one located at the front left will be referred to as the fifth antenna 9e.

[0033] The strength of the microwaves radiated from each of the antennas 9a to 9e decreases in proportion to the distance, but in Fig. 2 (and Figs. 9 to 11), the areas where strong microwaves can be irradiated (strong vibration areas) are shown by solid lines, and the areas where microwaves are weak are shown by dashed lines (strong vibration areas are shown by dotted lines in Figs. 4(B) to 7). Naturally, since the strength of microwaves decreases continuously in inverse proportion to the distance, it is not necessarily appropriate to describe them as strong or weak, and therefore, although the boundaries of the areas shown by circles in Fig. 2 are merely for convenience, it can be understood from Fig. 2 that strong microwaves can be irradiated to almost the entire heating chamber 2.

[0034] In the electrical equipment compartment 6 of the housing 1, a semiconductor oscillator (oscillating element), a power supply circuit, a control circuit, and the like (none of which are shown) are arranged. The control circuit includes a volatile memory, a non-volatile memory, a CPU, and the like. In this embodiment, since only one of the five antennas 9a to 9e is driven, only one semiconductor oscillator (oscillating element) is required. Microwaves are transmitted to each of the antennas 9a to 9e from the oscillator element via a change-over switch.

[0035] The specifications of each of the antennas 9a to 9e are shown in the table of Fig. 4(A). In this example, the frequency of each of the antennas 9a to 9e can be switched to three levels: 2400MHz, 2450MHz, and 2500MHz, and the output can be selected from three levels: 100W, 200W, and 300W. The oscillation time can be set in units of 0 seconds (no oscillation), 10 seconds, and 15 seconds, but other units such as 20 seconds can also be selected, and any time can also be selected.

[0036] Since there are five antennas 9a to 9e, 3125 types of oscillation sequences can be selected, 243 types of frequencies can be selected, 243 types of output can be selected, and 243 types of oscillation times can be selected including 0 seconds. Furthermore, the number of combinations of the four elements of oscillation sequence, frequency, output, and oscillation time becomes enormous, but patterns that are likely to be used are organized based on the standard type and size of the heated object, and multiple reference patterns are created.

[0037] An infrared temperature sensor 12 is disposed in a portion located at the center of the upper hollow portion 11 of the housing 1 in plan view. The temperature sensor 12 is configured to divide the heating chamber 2 into a number of areas and measure the temperature for each area. That is, in this embodiment, as shown in Fig. 4(B), the heating chamber 2 is divided into 5 x 5 = 25 unit areas E1 to E25 and the temperature is measured for each unit area E1 to E25.

[0038] In this case, the overall average value for each unit area E1-E25 may be taken and specified as the temperature of that unit area E1-E25, or the temperature (point temperature) at the center of each unit area E1-E25 may be specified as the temperature of that unit area E1-E25, as shown by the letter P in Fig. 6(A). As a method for specifying the temperature, it is possible to directly use actual measured values ​​such as 34°C and 46°C as the basis for control, or it is also possible to specify a temperature range, for example 25-29°C and 30-35°C, and control based on that temperature range.

[0039] It is possible to place multiple temperature sensors 12. A monitor, touch buttons, and the like are arranged on the front surface of the operation unit 4, and these are organized into one or more units.

[0040] (2) First control example Examples of control are shown in Fig. 5(B) to Fig. 8. These examples are for heating (warming) the object W, and the target value (surface temperature of the object W) is set to, for example, 85 to 90°C. The temperature detection mode is based on the average value of each of the individual unit areas E1 to E25.

[0041] The control modes of the microwave oven of this embodiment can be broadly divided into a method of heating based on a prepared control pattern and a method of setting the heating mode each time based on the temperature distribution of the heated object W (there is also a compromise between the two), but Fig. 6 shows an example of the former method. Therefore, many combinations of microwave output, frequency, and heating time from the multiple antennas 9a to 9e are stored in the memory of the control device.

[0042] 6, H indicates strong heating (e.g., irradiation for 15 seconds at 300 W), M indicates medium heating (e.g., irradiation for 15 seconds at 200 W), and L indicates low heating (e.g., irradiation for 15 seconds at 100 W). The two-digit number indicates the detected temperature (temperature range) of the heated object W.

[0043] 6, first, as shown in (A), the entire heating chamber 2 is heated strongly and evenly. Specifically, the entire heating chamber 2 is heated strongly with approximately the same intensity by driving each of the antennas 9a to 9e in sequence. That is, in the initial step (first heating step, first heating cycle), the entire heating chamber 2 is heated (vibrated) strongly and evenly.

[0044] If the heated object W is homogeneous as a whole, the degree of temperature rise will be uniform, but in actual food, the ingredients are mixed in a complex manner, and the heating characteristics of each ingredient are not the same, so the heated object is rarely heated uniformly. Therefore, antennas 9a to 9e are used to detect how the temperature of each part actually rose in each heating cycle using temperature sensor 12, and if there are temperature unevenness in each area, a heating pattern is selected to reduce the temperature unevenness, and the next heating cycle is performed.

[0045] By repeating this cycle, the temperature difference of the object to be heated is reduced, and it is possible to uniformly heat the object to be heated W. Therefore, in this control example, the temperature of the object to be heated W is measured for each heating cycle, and the heating pattern for the next cycle is selected based on the temperature unevenness of each cycle.

[0046] For example, in the heating state after the initial process, as shown in (B), the temperature of the 1st and 25th areas is 45°C, the 4th, 5th, 8th, 9th areas and the 16th, 17th, 21st, 22nd areas are 20°C, and the other areas are 30°C or 35°C, resulting in temperature unevenness. In order to reduce the temperature unevenness of (B), a comparison circuit is used to select from memory (C), which is the pattern closest to the temperature distribution of (B), and a second heating process is performed using the heating pattern of (C).

[0047] Then, the inside of the heating chamber 2 has a temperature distribution of (D), so the heating pattern (E) that is closest to the temperature distribution of (D) is selected from memory, and the third heating process is performed with the heating pattern (E). Furthermore, the sound and distribution after the heating of (E) is detected as (F), and the pattern (G) that is closest to (F) is selected to perform the fourth heating, and the target temperature of (H) is reached. This ends the heating process.

[0048] In Figure 6, the heating process is performed four times, but the number of heating processes will naturally differ depending on the degree of temperature unevenness and the target temperature. If no temperature unevenness is found in the temperature detection after the initial process, continue uniform heating while detecting the temperature with the temperature sensor, and stop driving when the target temperature is reached.

[0049] (3) Second control example 7 and 8 show an example of a method for setting the heating mode each time based on the temperature distribution of the heated object W. In this example as well, the heated object W is preheated as an initial step. In this case, the five antennas 9a to 9e may be driven sequentially, or, as shown by the cross-hatched display in FIG. 5(B), for example, only the first antenna 9a may be driven at a predetermined intensity and time (for example, at 300 W for 25 seconds (15 seconds + 10 seconds)).

[0050] Fig. 7(A) shows the temperature distribution after the initial step (first heating step). Almost no resistance occurs in areas away from the object W to be heated, so there is almost no increase in temperature, and the temperature rises at the location of the object W to be heated. Therefore, if the temperature is low in areas near the outer periphery of the heating chamber 2, it can be determined that the object W to be heated is not present in that low temperature area, and control can be continued. In other words, the shape of the object W to be heated can be detected from the temperature unevenness, and the approximate mass of the object W to be heated can be detected from the relationship between the microwave irradiation energy and the degree of temperature rise.

[0051] Now, the degree of temperature rise at the location of the heated object W varies depending on the contents, material, shape, etc. of the heated object W. For example, when there are many contents and ingredients, such as in a makunouchi bento, there is a large temperature unevenness, but when there are only a few contents and the contents are spread almost evenly in the container, such as in curry or yakisoba, there is little temperature unevenness. Also, when the contents are dense, such as a block of meat, the degree of temperature rise is low, and when the contents are thin, such as tofu, the temperature rises easily.

[0052] Therefore, the antennas 9a to 9e are driven one by one so as to reduce the temperature unevenness. In Fig. 7(B), as a first heating stage in which heating is performed while reducing the temperature unevenness in Fig. 7(A), the fourth antenna 9d is driven for 15 seconds at 300 W, for example, and as a result, the temperature distribution in the heating chamber 2 changes as shown in Fig. 8(A), and the temperature of the object to be heated W increases overall while the temperature unevenness is reduced. Therefore, as a second heating stage, the second antenna 9b is driven for 15 seconds at 300 W, for example, as shown by the cross-hatched display in Fig. 8(B).

[0053] Although the temperature distribution in the heating chamber 2 after the second heating stage is not shown, the temperature of the object to be heated W increases overall, and the temperature unevenness is reduced compared to Fig. 8(A). In this way, the antennas 9a to 9e are driven one by one, thereby raising the temperature of the object to be heated W as a whole to a predetermined temperature (target temperature).

[0054] When the temperature unevenness of the object W to be heated has settled to a certain degree (for example, within 10°C), the antennas 9a to 9e can be driven in order to heat the object. For example, they can be driven clockwise or counterclockwise from the top of FIG. 8(A). They can also be driven in a diagonal direction. For example, the order is first antenna 9a ⇒ fourth antenna 9d ⇒ fifth antenna 9e ⇒ third antenna 9c.

[0055] In any case, if the temperature rise is weak in the center of the heating chamber 2, the first antenna 9 should be driven appropriately. In other words, if the temperature unevenness increases while heating in the basic pattern, the antennas 9a to 9e should be driven intensively in correspondence with the low temperature areas to correct the unevenness.

[0056] When driving each of the antennas 9a to 9e, the output, irradiation time, and frequency can be combined to adjust the temperature rise to be uniform. The order of heating and the selection of the output and time can be set based on a map created by experiment. If the predicted temperature and the actual temperature rise differ during the intermediate heating stage, feedback control can be used to correct the map.

[0057] The degree of temperature unevenness of the object W to be heated also varies greatly depending on the size (planar area) of the object W to be heated. For example, if the object W to be heated is small enough to fit within the strong irradiation area of ​​the first antenna 9a, it is understood that there will be almost no temperature unevenness, and in this case, it is possible to heat the object W by continuously driving only the first antenna 9a. 1 Continuous use of only the antennas 9a to 9e is also included in the present invention.

[0058] A feature of the semiconductor type microwave exciter is that the frequency can be easily controlled, and in this embodiment, this feature can be utilized to change the frequency to three levels. Therefore, by switching the frequency according to the size, shape, etc. of the object W to be heated and adjusting the range in which the microwave is strongly irradiated, the microwave can be efficiently irradiated onto the object W to be heated. Note that the frequency can be selected at any value within the legal range.

[0059] (4) Other embodiments In the second embodiment shown in FIG. 9, nine antennas 13a to 13i are provided in three rows in the front and depth directions. 9 In this state, the antennas are numbered 13a, 13b, 13c, etc. from left to right toward the front. In short, the antennas 13a to 13i are arranged in three rows of three each.

[0060] Using multiple antennas 13a-13i as in the embodiment of Fig. 9 has the advantage that the range of strong microwaves can be expanded to cover the entire heating chamber 2, thereby enabling precise heating. Furthermore, in the embodiment of Fig. 9, there are multiple common regions 14 where the strong vibration areas of adjacent antennas 13a-13i overlap, and by driving adjacent antennas 13a-13i, pinpoint heating is possible using these common regions 14. This aspect also contributes to the realization of precise heating modes.

[0061] It can be said that increasing the number of antennas can promote uniform heating, but this increases costs. In addition, in the case of actual heated objects W, it can be said that there is a high demand for uniform heating, warming, and thawing of the entire object. Therefore, a structure that can heat uniformly while minimizing the number of antennas is realistic.

[0062] From such a practical viewpoint, in the third embodiment shown in Fig. 10, as a modification of the first embodiment in which five antennas 9a to 9e are used, the five antennas 9a to 9e are arranged in a petal shape with the intervals between them narrowed. In other words, the object W to be heated is usually much smaller than the planar area of ​​the heating chamber 2, and it can be said that there is no practical situation in which the entire heating chamber 2 needs to be heated strongly. Therefore, the five antennas 9a to 9e are arranged in a petal shape as in the first embodiment. Condition In arranging the antennas, the second to fifth antennas 9b to 9e are closer to the center than in the first embodiment.

[0063] In this embodiment, the second to fifth antennas 9b to 9e are driven in the circumferential or diagonal direction in sequence as a basic drive pattern, so that the object to be heated W can be heated evenly. Of course, the first antenna 9a may be driven according to the degree of temperature rise of the object to be heated W. Also, as an initial step, the second to fifth antennas 9a to 9e may be driven for, for example, 10 seconds each to heat the object to be heated W as a whole (this also applies to the first embodiment).

[0064] 11 also uses five antennas 9a to 9e as in the first embodiment, but in this fourth embodiment, the first antenna 9a and the fourth and fifth antennas 9d and 9e are moved toward the back, and the left-right space between the fourth and fifth antennas 9d and 9e is narrowed. Therefore, the strong oscillation areas of adjacent antennas 9a to 9e overlap each other.

[0065] In the fourth embodiment, the strong oscillation area covers almost the entire area where the object to be heated W is placed. In this embodiment, three antennas 9a to 9e are arranged side by side on the back side, and two antennas 9a to 9e are arranged side by side on the front side, forming a two-row system.

[0066] The heating pattern is as follows: 4 Antenna 9d⇒ Fifth AntennaVarious methods can be adopted, such as a horizontal movement method such as 9e ⇒ second antenna 9b ⇒ first antenna 9a ⇒ third antenna 9c, or a zigzag method such as 2nd antenna 9b ⇒ fourth antenna 9d ⇒ first antenna 9a ⇒ fifth antenna 9e ⇒ third antenna 9c. Based on the temperature distribution detected in the initial process, the optimal pattern that reduces temperature unevenness can be adopted.

[0067] 12, six antennas 15a to 15f are arranged in two rows, one in front and one in back. In this embodiment, the strong vibration areas of adjacent antennas 15a to 15f overlap each other, so that the object W can be precisely heated in as short a time as possible.

[0068] Although the embodiment of the present invention has been described above, the present invention can be embodied in various ways in terms of both structure and control mode. Regarding the structure, for example, the antenna can be disposed in the upper space of the housing. Alternatively, the antenna can be disposed in both the upper space and the lower space.

[0069] It is also possible to adopt a structure in which the heating chamber is divided into multiple heating areas, and these areas are displayed on the operation unit as non-heating selection areas, so that when a specific area is touched, that area will not be heated (or will be heated weakly). It is also possible to provide buttons for selecting "high heat" and "low heat" with no touch as the standard for the degree of heating. It is also possible to provide buttons for selecting between heating and defrosting.

[0070] As a mode of control, after the initial heating step, a method can be adopted in which the temperature difference inside the heating chamber is thermobluffed by a temperature sensor, the shape and temperature unevenness of the object to be heated are read, and the low-temperature parts of the object to be heated are concentratedly heated. As already mentioned, the temperature of the outer parts of the object to be heated hardly increases even when microwaves are irradiated, so it is possible to grasp the boundary where the temperature difference is clearly apparent (the boundary of the temperature range close to room temperature) as the outer shape of the object to be heated, and based on the shape (and mass) of the object to be heated thus grasped, microwaves can be efficiently irradiated to the object to be heated. [Industrial Applicability]

[0071] The present invention can be embodied in a semiconductor oscillator microwave oven, and therefore has industrial applicability. [Explanation of symbols]

[0072] 1 Case 2 Heating chamber 3 Doors 4 Control section 6 Electrical Equipment Room 7 Flat Table 8 Lower hollow part 9a~9e Antennas 11 Upper hollow part 12 Temperature Sensor 13a~13i Antenna 14 Common area where strong excitation areas overlap 15a~15f Antenna E1~E25 Temperature distribution unit area (address)

Claims

1. A plurality of microwave oscillation antennas made of semiconductors are arranged at horizontal intervals on the bottom or top of a heating chamber equipped with a door, and each of the microwave oscillation antennas is set so that a plurality of antennas are not driven simultaneously but are driven one by one; The semiconductor oscillation microwave oven further includes temperature sensors for detecting a surface temperature of an object to be heated placed in the heating chamber at a plurality of positions, and when it is determined that there is a temperature unevenness in the object to be heated, each of the microwave oscillation antennas is driven so as to raise the temperature to a preset temperature while correcting the temperature unevenness based on the temperature detected by the temperature sensor, First, one or more microwave oscillating antennas are driven for a predetermined time, and then the temperature of the object to be heated is detected. If it is determined based on the detection result that there is temperature unevenness, the driving sequence of each of the microwave oscillating antennas is determined. Semiconductor oscillator microwave oven.

2. A plurality of semiconductor microwave oscillating antennas are arranged horizontally spaced apart on the bottom or top of a heating chamber equipped with a door, and each of the microwave oscillating antennas is set to be driven one by one, not driven simultaneously; The semiconductor oscillation microwave oven further includes temperature sensors for detecting a surface temperature of an object to be heated placed in the heating chamber at a plurality of positions, and when it is determined that there is a temperature unevenness in the object to be heated, each of the microwave oscillation antennas is driven so as to raise the temperature to a preset temperature while correcting the temperature unevenness based on the temperature detected by the temperature sensor, Each of the microwave oscillation antennas can select a plurality of outputs and drive times, and the drive sequence, output, and drive time of each of the microwave oscillation antennas are controlled to reduce the temperature unevenness of the heated object by combining them. Semiconductor oscillator microwave oven.

3. At least four microwave oscillation antennas are arranged, The temperature sensor is capable of detecting temperatures of the object to be heated in a number of areas, When it is determined that there is a temperature unevenness in the heated object, the microwave oscillation antenna located at the part with a low temperature is driven once or a plurality of times, so that the temperature of the heated object as a whole is evenly raised to a predetermined temperature.

3. A semiconductor oscillation microwave oven according to claim 1 or 2.

4. A plurality of reference maps are created in which the output, driving time and driving sequence of each microwave oscillating antenna are set corresponding to a plurality of reference patterns with different temperature unevenness, and when the temperature unevenness of the actual heated object is the same as or close to any of the reference patterns, each microwave oscillating antenna is driven based on the reference map corresponding to that reference pattern.

4. A semiconductor oscillator microwave oven according to claim 1.

5. The heating device is controlled so that a part of the object to be heated is not heated.

4. A semiconductor oscillator microwave oven according to claim 1.

6. The operation panel is provided with an operation section that allows the user to select a heating area.

4. A semiconductor oscillator microwave oven according to claim 1.

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