High-frequency processing device

Abstract

A high-frequency processing apparatus of one embodiment of the present disclosure includes a heating chamber that houses an object to be heated, an oscillation section, at least one power supply section, a detection section, and a control section. The oscillation section generates high-frequency power having an arbitrary frequency in a predetermined frequency band. The at least one power supply section supplies incident power based on the high-frequency power to the heating chamber. The detection section detects the incident power and reflected power returned from the heating chamber to the at least one power supply section. The control section causes the oscillation section to perform frequency sweeping and measures a reflection characteristic based on the incident power and the reflected power of each heating condition including a frequency. The control section decides a heating condition to be used next based on a reflection variation amplitude representing a change in the reflection characteristic of each heating condition. According to this embodiment, various objects to be heated can be optimally heated.

Description

Technical Field

[0001] This disclosure relates to a high-frequency treatment device. Background Technology

[0002] For example, Patent Document 1 describes a correlation, or modal condition, between the wavelength of an electric wave and the size of the housing in a manner that allows resonance in a heated space.

[0003] According to Patent Document 1, if the modal conditions are met, heating with the desired heating distribution can be achieved by selecting a combination of field pattern and power supply. The combination of field pattern and power supply is determined by parameters related to frequency, phase, and other MSE (Modulation Space Elements).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2016-129141 Summary of the Invention

[0007] However, depending on the shape, quantity, number of processes, configuration, and dielectric constant distribution within the heated object, the distribution of the electricity absorbed by the heated object changes. When the heated object is heated with high-frequency electricity under this influence, the electromagnetic field distribution within the shell shifts compared to the unloaded resonant state.

[0008] At the start of heating, it is difficult to estimate the distribution of high-frequency electricity during heating. While infrared sensors can be used to detect changes in temperature distribution during heating, generating an electromagnetic field distribution capable of correcting for the resulting temperature unevenness is extremely difficult.

[0009] Without a proper understanding of the distribution of electricity absorbed by the object being heated, even switching frequencies cannot substantially improve uneven heating.

[0010] This disclosure is intended to solve the aforementioned problems and aims to provide a high-frequency processing apparatus capable of appropriately heating various heated objects.

[0011] One aspect of the high-frequency processing apparatus disclosed herein includes: a heating chamber for containing a heated object; an oscillation unit; at least one power supply unit; a detection unit; and a control unit.

[0012] An oscillation unit generates high-frequency electricity at any frequency within a defined frequency band. At least one power supply unit supplies incident electricity based on the high-frequency electricity to the heating chamber. A detection unit detects the incident electricity and the reflected electricity returning from the heating chamber to at least one power supply unit.

[0013] The control unit causes the oscillation unit to perform a frequency scan and measures the reflection characteristics based on the incident and reflected power for each heating condition, including the frequency. The control unit then determines the next heating condition to be used based on the magnitude of the reflection variation, which represents the change in reflection characteristics for each heating condition.

[0014] This method enables optimal heating of various objects. Attached Figure Description

[0015] Figure 1 This is a schematic configuration diagram of a high-frequency processing apparatus illustrating an example of an embodiment of the present disclosure.

[0016] Figure 2A It means targeting Figure 1 The diagram shows a schematic representation of the analytical model.

[0017] Figure 2B It means Figure 2A The diagram shows the distribution of physical properties of the heated object before heating in the analytical model.

[0018] Figure 2C It means Figure 2A The diagram shows the distribution of physical properties of the heated object in the analytical model.

[0019] Figure 3A This is a diagram illustrating an example of the frequency characteristics of reflected electricity in one embodiment.

[0020] Figure 3B This is a diagram illustrating another example of the frequency characteristics of reflected electricity in one embodiment.

[0021] Figure 4A This is a contour map showing an example of the power absorption distribution in one embodiment.

[0022] Figure 4B This is a contour map showing an example of the power absorption distribution in one embodiment.

[0023] Figure 5 This is a schematic configuration diagram of a high-frequency processing apparatus illustrating other examples of embodiments of the present disclosure.

[0024] Figure 6A It means targeting Figure 5 The diagram shows a schematic representation of the analytical model.

[0025] Figure 6B It means Figure 6A The diagram shows the distribution of physical properties of the heated object before heating in the analytical model.

[0026] Figure 6C It means Figure 6A The diagram shows the distribution of physical properties of the heated object in the analytical model.

[0027] Figure 7A This is a contour plot illustrating an example of the frequency and phase characteristics of reflected electricity in other embodiments.

[0028] Figure 7B This is a contour plot illustrating an example of the frequency and phase characteristics of reflected electricity in other embodiments.

[0029] Figure 7C This is a contour plot illustrating an example of the frequency and phase characteristics of reflected electricity in other embodiments.

[0030] Figure 8 This is a contour map showing an example of the power absorption distribution in other embodiments of the implementation.

[0031] Figure 9 This is a flowchart illustrating the overall heating control of the implementation method.

[0032] Figure 10 This is a flowchart showing the detailed process of detecting and processing DT1.

[0033] Figure 11 This is a flowchart showing the detailed process of detecting and processing DT2. Detailed Implementation

[0034] The high-frequency processing apparatus of the first aspect of this disclosure includes: a heating chamber for housing the object to be heated; an oscillation unit; at least one power supply unit; a detection unit; and a control unit.

[0035] The oscillation unit generates high-frequency power at any frequency within a defined frequency band. At least one power supply unit supplies incident power based on the high-frequency power to the heating chamber. The detection unit detects the incident power and the reflected power returning from the heating chamber to at least one power supply unit.

[0036] The control unit causes the oscillation unit to perform a frequency scan and measures the reflection characteristics based on the incident and reflected power for each heating condition, including the frequency. The control unit then determines the next heating condition to be used based on the magnitude of the reflection variation, which represents the change in reflection characteristics for each heating condition.

[0037] The high-frequency processing apparatus of the second aspect of this disclosure is based on the first aspect and further includes a phase adjustment unit. At least one power supply unit includes a first power supply unit and a second power supply unit.

[0038] The phase adjustment unit is connected to the oscillation unit and adjusts the phase difference between the high-frequency power supplied by the first power supply unit and the high-frequency power to be supplied by the second power supply unit. The control unit causes the phase adjustment unit to perform a phase scan and measures the reflection characteristics based on the incident power and reflected power for each heating condition, which also includes the phase difference.

[0039] In the third-party high-frequency processing apparatus disclosed herein, based on the first method, the control unit determines the heating condition to be used next when the absolute value of the reflection variation amplitude is less than a threshold.

[0040] In the high-frequency processing apparatus of the fourth embodiment of this disclosure, based on the third embodiment, the threshold is a value obtained by multiplying the absolute value of the reflection variation amplitude by a predetermined coefficient.

[0041] The high-frequency processing apparatus of the fifth aspect disclosed herein is based on the first aspect and further includes a storage unit. Whenever the heating conditions to be used next are determined, the control unit causes the storage unit to store the reflection characteristics.

[0042] In the high-frequency processing apparatus of the sixth aspect of this disclosure, based on the fifth aspect, the control unit calculates the maximum value of the reflection variation amplitude each time it calculates the reflection variation amplitude, stores the maximum value in the storage unit, and determines the heating conditions to be used next based on the maximum value.

[0043] In the high-frequency processing apparatus of the seventh aspect of this disclosure, based on the fifth aspect, the control unit calculates the cumulative value of the reflection variation amplitude each time the reflection variation amplitude is calculated, stores the cumulative value in the storage unit, and determines the heating conditions to be used next based on the cumulative value.

[0044] In the high-frequency processing apparatus of the eighth aspect of this disclosure, based on the second aspect, the control unit replaces the value of the reflection variation amplitude under each heating condition that has a different sign than the value of the reflection variation amplitude under the same heating condition as the past with 0.

[0045] In the high-frequency processing apparatus of the ninth aspect of this disclosure, based on the fifth aspect, frequency scanning is an operation of changing the frequency at uniform or non-uniform intervals throughout a specified frequency band. Phase scanning is an operation of changing the phase difference at uniform or non-uniform intervals throughout a specified angular range.

[0046] In the high-frequency processing apparatus of the tenth aspect of this disclosure, based on the fifth aspect, the control unit causes the storage unit to store only the reflection characteristics that exhibit changing extreme values.

[0047] Below, refer to the appendix. Figure 1 The embodiments of this disclosure will be described in detail below.

[0048] Figure 1 This is a schematic configuration diagram of a high-frequency processing apparatus illustrating an example of an embodiment of the present invention. Figure 1 As shown, the high-frequency processing device according to this embodiment includes a heating chamber 1, an oscillation unit 3, an amplification unit 4a, a power supply unit 5a, a detection unit 6a, a control unit 7, and a storage unit 8.

[0049] The heating chamber 1 houses the food or other items to be heated, which serve as a load. The oscillation unit 3 is composed of semiconductor elements. The oscillation unit 3 is capable of generating high-frequency power with a frequency within a specified frequency band, and generates high-frequency power at a frequency specified by the control unit 7.

[0050] The amplification unit 4a is composed of semiconductor elements. The amplification unit 4a amplifies the high-frequency power generated by the oscillation unit 3 according to the instruction of the control unit 7, and outputs the amplified high-frequency power.

[0051] The power supply unit 5a functions as an antenna, supplying the high-frequency power amplified by the amplification unit 4a as incident power to the heating chamber 1. That is, the power supply unit 5a supplies incident power based on the high-frequency power generated by the oscillation unit 3 to the heating chamber 1. The power in the incident power that is not consumed by the heated object 2, etc., becomes reflected power returning from the heating chamber 1 to the power supply unit 5a.

[0052] The detection unit 6a is, for example, composed of a directional coupler. The detection unit 6a detects incident and reflected electricity and notifies the control unit 7 of the detected amounts of incident and reflected electricity. That is, the detection unit 6a functions as both an incident electricity detection unit and a reflected electricity detection unit.

[0053] The detection unit 6a, for example, has a coupling degree of approximately -40 dB and extracts approximately 1 / 10,000 of the incident and reflected power. The extracted incident and reflected power are rectified by a detector diode (not shown) and smoothed by a capacitor (not shown), converting them into information corresponding to the incident and reflected power. The control unit 7 receives this information.

[0054] The storage unit 8 is composed of a semiconductor memory or the like, stores data from the control unit 7, reads out the stored data and sends it to the control unit 7.

[0055] The control unit 7 is composed of a microprocessor including a CPU (Central Processing Unit). The control unit 7 controls the oscillation unit 3 and the amplification unit 4a based on information from the detection unit 6a and the storage unit 8, and performs heating control in the high-frequency processing device.

[0056] Figure 2A It means targeting Figure 1 The diagram shows a schematic representation of the analytical model of the structure. Figure 2B as well as Figure 2C Three-dimensional representation Figure 2A The distribution of physical property values ​​within the heated object 2 in the analytical model shown.

[0057] Figure 2B This indicates the distribution of physical properties within the heated object 2 before heating. For example... Figure 2B As shown, the object to be heated 2 before heating is frozen meat 2b with uniform physical properties.

[0058] Figure 2C This represents the distribution of physical properties of the heated object 2 after being heated for a specified time by high-frequency electric heating at a frequency of 2.45 GHz. For example... Figure 2C As shown, the heated object 2 has: a portion having the physical properties of frozen meat 2b; and a portion having the physical properties of thawed meat 2a. That is, the heated object 2 contains a mixture of thawed meat 2a and frozen meat 2b.

[0059] Figure 3A as well as Figure 3B This is a graph illustrating an example of the frequency characteristics of reflected electricity. To obtain the frequency characteristics of reflected electricity, the oscillator 3 supplies high-frequency electricity while performing frequency scanning. Frequency scanning refers to the operation of the oscillator 3, which sequentially changes the frequency at predetermined frequency intervals throughout a specified frequency band.

[0060] In this embodiment, the specified frequency band is 2.4 GHz to 2.5 GHz, and the specified frequency interval is 0.01 GHz. The specified frequency interval can be uniform or non-uniform. The detection unit 6a detects the reflected power of the high-frequency power relative to each supplied frequency.

[0061] The amount of high-frequency power consumed by the heated object 2 varies depending on the frequency of the supplied high-frequency power. Similarly, the power loss in the heating chamber 1 and the resonance of the heating chamber 1 also vary depending on the frequency of the supplied high-frequency power. Based on these frequency characteristics, the amount of high-frequency power loss consumed in the heating chamber 1 changes, and consequently, the reflected electrical force also changes.

[0062] Here, the graph representing the ratio (dB) of reflected electric force to incident electric force at each frequency (GHz) is called the reflection characteristic 9.

[0063] Figure 3A Indicating targeting Figure 2B The reflection characteristics 9 (dashed line) of the heated object 2 before heating and the characteristics of the object before heating are shown. Figure 2CThe reflection characteristics 9 (solid line) of the heated object 2 after heating are shown. The curve representing the former is called reflection characteristic curve 9A, and the curve representing the latter is called reflection characteristic curve 9B.

[0064] Figure 4A , Figure 4B This illustrates an example of the distribution of power absorbed by a load. In this embodiment, the distribution of power absorbed by the load is referred to as the absorbed power distribution.11 Figure 4A , Figure 4B The distribution of absorbed electricity obtained by analyzing the state of the heated object 2, which is frozen meat 2b, is represented by a contour plot.

[0065] Figure 4A This is a three-dimensional perspective view showing the absorbed power distribution 11 within the heated object 2 when supplied with high-frequency power at a frequency of 2.45 GHz. Figure 4A When the high-frequency power thawing time of the power absorption distribution 11 shown is specified, it has Figure 2B The distribution of physical property values ​​shown for the heated object 2 has Figure 2C The distribution of physical property values ​​is shown.

[0066] Figure 4B This represents the power absorption distribution 11 observed from above of the heated object 2 under various heating conditions, while simultaneously supplying high-frequency power during frequency scanning. For example... Figure 4B As shown, the frequencies used in the frequency scan are set in 0.01 GHz increments, from 2.4 GHz to 2.5 GHz. Figure 4B In the middle, the absorbed power distribution 11 obtained at each frequency is arranged from left to right in order of frequency.

[0067] like Figure 3A As shown, a difference exists between the two reflection characteristics 9 before and after heating at frequencies ranging from approximately 2.45 GHz to approximately 2.48 GHz. This difference is caused by the thawing of a portion of the heated object 2. Hereinafter, the difference between the two reflection characteristics 9 before and after heating will be referred to as the reflection variation amplitude 12. Figure 3B It is a line graph showing the reflection variation amplitude of 12 for each frequency.

[0068] like Figure 3B As shown, the reflection variation amplitude 12 varies at each frequency. The reason for the variation in the reflection variation amplitude 12 is that a portion of the heated object 2 is thawed. A reflection variation amplitude 12 close to 0 means that at that frequency, the reflected electrical force is almost unaffected by the thawing of a portion of the heated object 2.

[0069] For example, in Figure 3BAt a frequency of 2.49 GHz where the mid-reflection variation amplitude is close to 0 (12), if... Figure 4B The power absorption distribution shown in Figure 11 and Figure 2C When the distributions shown are compared, the patterns of the distributions are different from each other.

[0070] That is, in the frequency band where the reflection variation amplitude 12 is close to 0, the high-frequency power irradiated onto the thawed part (thawed meat 2a) of the heated object 2 is small, so it has almost no effect on the reflected power.

[0071] exist Figure 4B middle, Figure 4B The absorbed power distribution 11 shown is related to Figure 4A and Figure 2C The distributions that differ from the electromagnetic field strength are enclosed by dashed lines (the ranges of 2.48 GHz to 2.50 GHz and 2.40 GHz to 2.43 GHz). These ranges are different from... Figure 3B The frequency bands where the reflection variation amplitude of 12 is close to 0 are roughly the same.

[0072] That is, if from Figure 3B By selecting the next frequency from the frequency band where the reflection variation amplitude 12 is close to 0, it is possible to generate an absorption power distribution 11 that is different from the absorption power distribution 11 at the 2.45 GHz frequency used for heating without increasing the reflected power. That is, here, the frequency of the high-frequency power is the heating condition.

[0073] Figure 5 This is a schematic configuration diagram of a high-frequency processing apparatus according to another example of this embodiment. In this other example of the high-frequency processing apparatus, the same reference numerals are used to label the components that are substantially the same as those in the high-frequency processing apparatus of the first example described above, and their descriptions are omitted as appropriate.

[0074] like Figure 5 As shown, the high-frequency processing device in this other example, in addition to having Figure 1 In addition to the power supply path shown, there is a second power supply path, which includes an amplification section 4b, a power supply section 5b, and a detection section 6b that are equivalent to the amplification section 4a, the power supply section 5a, and the detection section 6a, respectively. In this configuration, reflected power is returned from the heating chamber 1 to the power supply sections 5a and 5b, respectively. The power supply sections 5a and 5b are equivalent to the first power supply section and the second power supply section, respectively.

[0075] The second power supply path includes a phase adjustment section 10 disposed between the oscillation section 3 and the amplification section 4b. The phase adjustment section 10 is composed of a variable capacitor element, the capacitance of which changes according to the applied voltage, etc. The phase adjustment section 10 may be integrally formed with the oscillation section 3 or separately formed from the oscillation section 3.

[0076] The phase adjustment unit 10 can operate in a manner that adjusts the phase of the input high-frequency power within a range of 0 degrees to approximately 180 degrees. That is, the phase adjustment unit 10 can adjust the phase difference between the two high-frequency powers supplied from the power supply units 5a and 5b to any degree between -180 degrees and +180 degrees.

[0077] In this configuration, the two high-frequency powers supplied from power supply units 5a and 5b have a single frequency and different phases adjusted by phase adjustment unit 10.

[0078] By adjusting the phase difference, the phase of the high-frequency electricity synthesized in heating chamber 1 can be changed, and the electromagnetic field distribution within heating chamber 1 can also be changed. That is, the electromagnetic field distribution within heating chamber 1 changes due to two main factors: the frequency and phase difference of the two supplied high-frequency electricity sources. In this case, the combination of the frequency and phase difference of the two high-frequency electricity sources constitutes the heating condition. In this embodiment, the two high-frequency electricity sources have a single frequency.

[0079] Figure 6A It means targeting Figure 5 The diagram shows a schematic representation of the analytical model of the structure. Figure 6B and Figure 6C and Figure 2B and Figure 2C Similarly, it is represented in three dimensions. Figure 6A The diagram shows the distribution of physical property values ​​within the heated object 2 in the analytical model.

[0080] Figure 6B This indicates the distribution of physical properties within the heated object 2 before heating. For example... Figure 6B As shown, the object to be heated 2 before heating is frozen meat 2b with uniform physical properties as a whole.

[0081] Figure 6C This represents the distribution of physical properties of the heated object 2 after being heated for a specified time by two high-frequency electric heating devices with a frequency of 2.47 GHz and a phase difference of 180 degrees. For example... Figure 6C As shown, the heated object 2 has: a portion having the physical properties of frozen meat 2b; and a portion having the physical properties of thawed meat 2a. That is, in Figure 6C The heated object 2 shown contains a mixture of thawed meat 2a and frozen meat 2b.

[0082] Figures 7A to 7C This is a contour plot showing an example of the frequency and phase characteristics of reflected power. To obtain the frequency and phase characteristics of the reflected power, the oscillation unit 3 supplies high-frequency power while performing a frequency scan. The phase adjustment unit 10 performs a phase scan on the input high-frequency power and outputs high-frequency power with a phase change.

[0083] Phase scanning refers to the operation of the phase adjustment unit 10, which sequentially changes the phase difference of two high-frequency electrical signals across a predetermined angular range at predetermined angular intervals. In this embodiment, the predetermined angular range is 0 degrees to 300 degrees, and the predetermined angular interval is 60 degrees. The predetermined angular interval can be uniform or non-uniform. Detection units 6a and 6b detect reflected electrical signals in various combinations of frequency and phase difference.

[0084] exist Figures 7A to 7C In the diagram, the horizontal axis represents frequency (GHz) and the vertical axis represents phase difference (degrees). Figures 7A to 7C This represents the ratio (dB) of the reflected electric force to the incident electric force in each combination of frequency and phase difference. Figures 7A to 7C The brightness of the region in the diagram means that, based on the heating conditions corresponding to the brighter region, the aforementioned ratio can be increased.

[0085] and Figure 3A , Figure 3B Similarly, due to changes in the consumption and loss of high-frequency power, which depends on frequency, the amount of high-frequency power consumed in heating chamber 1 changes. Therefore, the reflected electric force also changes accordingly.

[0086] Furthermore, the electromagnetic field distribution within heating chamber 1 changes according to the phase difference of the high-frequency power, and the amount of high-frequency power lost in heating chamber 1, such as the power absorbed by the load, also changes. Therefore, the reflected electric force also changes accordingly. Here, [the text continues with further details]. Figures 7A to 7C The contour map shown is called the reflection characteristic 9.

[0087] Figure 7A Relative to Figure 6B The reflective properties 9 of the heated object 2 before heating are shown. Figure 7B Relative to Figure 6C The reflective properties 9 of the heated object 2 after heating are shown. Figure 7C This represents the difference between the two reflection characteristics 9 before and after heating. (and) Figure 3B Similarly, this difference is referred to as the reflection variation amplitude 12.

[0088] Figure 7A , Figure 7B Indicates to Figure 1 The reflection characteristics 9 of the high-frequency processing device shown are given when the heating conditions (frequency) are increased by a phase difference. Figure 7C This represents the reflection variation 12 calculated by subtracting the value (dB) of the reflection characteristic curve 9A from the value (dB) of the reflection characteristic curve 9B for each combination of frequency and phase difference.

[0089] For example, in Figure 7CIn the heating condition with a frequency of 2.47 GHz and a phase difference of 180 degrees, the reflection variation amplitude is 2.4 dB.

[0090] Figure 8 This represents the power absorption distribution 11 of the heated object 2 as observed from below under various heating conditions, when two high-frequency powers are supplied simultaneously for frequency scanning and phase scanning. Figure 8 right Figure 6B The state of the heated object 2, which is shown as frozen meat 2b, is analyzed, and the resulting absorbed electricity distribution 11 is represented by a contour plot. Figure 8 In the figure, the absorbed power distribution 11 obtained under various heating conditions is arranged in a matrix with the horizontal axis as the frequency and the vertical axis as the phase difference.

[0091] like Figure 8 As shown, the individual frequencies of the two high-frequency electrical components are set in 0.01 GHz increments from 2.4 GHz to 2.5 GHz. The phase difference between the two high-frequency electrical components is set in 60-degree increments from 0 degrees to 300 degrees.

[0092] like Figure 8 As shown, when two high-frequency electrical circuits with a frequency of 2.47 GHz and a phase difference of 180 degrees are used to defrost for a specified time, the following conditions are met: Figure 6B The distribution of physical property values ​​shown for the heated object 2 has Figure 6C The distribution of physical property values ​​is shown.

[0093] Will generate with Figure 8 The heating conditions of the power absorption distribution 11 shown, with a frequency of 2.47 GHz and a phase difference of 180 degrees, are similar to those of the power absorption distribution 11 shown. These heating conditions are referred to as similar heating conditions 13. Similar heating conditions 13 are... Figure 7C The combination of the most variable frequencies and phase differences in the reflection characteristics 9 shown for the reflection variation amplitude 12 is roughly the same.

[0094] Therefore, similar to the example described above in this embodiment, as long as from Figure 7C The frequency and phase difference to be used next can be selected from the frequency and phase difference where the reflection variation amplitude 12 is close to 0. Thus, it is possible to generate an absorption power distribution 11 that is different from the absorption power distribution 11 at the frequency of 2.47 GHz and the phase difference of 180 degrees used for heating without increasing the reflected power.

[0095] In other examples of this embodiment, frequency and phase difference are used as heating conditions. However, even if the heating conditions include other variable factors such as the selection of the power supply, the power absorption distribution 11 can be varied using the same principle.

[0096] Figure 9This is a flowchart illustrating the overall heating control of this embodiment. When the user instructs to start cooking using the operation unit (not shown), the control unit 7 first performs detection processing DT1 (step S1).

[0097] Figure 10 This is a flowchart illustrating the details of the detection and processing step DT1 (S1). For example... Figure 10 As shown, the control unit 7 measures the reflection characteristics 9 based on the reflected power detected by frequency scanning at each frequency (step S11).

[0098] The control unit 7 stores the reflection characteristic 9 in the storage unit 8 in correspondence with the heating conditions used (step S12). The control unit 7 determines the heating conditions by considering the reflection characteristic 9, heating efficiency, etc. (step S13) and ends the detection process DT1.

[0099] return Figure 9 The control unit 7 heats the object to be heated according to the determined heating conditions (step S2). After heating for a certain period of time, the control unit 7 performs detection processing DT2 (step S3).

[0100] Figure 11 This is a flowchart illustrating the details of the detection process DT2. In the detection process DT2, the control unit 7 measures the reflection characteristic 9 based on the reflected electricity detected at each frequency through frequency scanning (step S21). The control unit 7 stores the obtained reflection characteristic 9 in the storage unit 8, corresponding to the heating conditions used (step S22).

[0101] The control unit 7 calculates the reflection variation amplitude 12 based on the difference between the two reflection characteristics 9 measured in detection processing DT1 and detection processing DT2 (step S23). After cooking begins, the first calculation of the reflection variation amplitude 12 is performed using the result of detection processing DT1 and the result of the initial detection processing DT2 after heating. The calculation of the reflection variation amplitude 12 thereafter is performed using the result of the previous detection processing DT2 and the result of the current detection processing DT2.

[0102] Control unit 7 pairs with heat treatment ( Figure 9 The threshold is calculated by multiplying the absolute value of the reflection variation amplitude 12 under the same heating conditions as in step S2) by a predetermined coefficient (step S24). The control unit 7 sets the threshold to a value smaller than each value of the reflection variation amplitude 12 measured under the heating conditions by setting the coefficient to a positive value smaller than 1.

[0103] Next, the control unit 7 will select the value of the reflection variation amplitude 12 obtained in step S23 that has the same characteristics as in... Figure 9In step S2, the value of the reflection variation amplitude 12 under the same heating conditions as in the past is replaced with a value of "0" (step S25).

[0104] Based on heating conditions where the absolute value of each value of the adjusted reflection variation amplitude 12 is less than a certain threshold, such as referring to... Figure 4A , Figure 4B , Figure 8 As explained, the power absorption distribution 11 can be varied. Therefore, the control unit 7 determines this heating condition as the heating condition to be used next. Each time the control unit 7 determines the heating condition to be used next, it stores the reflection characteristic 9 in the storage unit 8 (step S26) and ends the detection process DT2.

[0105] return Figure 9 The control unit 7 monitors the cooking progress based on the information obtained in the detection process DT2 (step S3) (step S4). Based on the cooking progress, the control unit 7 determines whether cooking should be stopped, and stops or continues cooking based on the result (step S5).

[0106] If cooking continues (No in step S5), the control unit 7 updates the heating conditions (step S6) by setting the heating conditions determined in the detection process DT2 (step S3) to the actual heating conditions, and then proceeds to the next heating process. If cooking ends (Yes in step S5), the control unit 7 stops the oscillation unit 3 and ends the cooking process.

[0107] Thus, by using the updated heating conditions, an absorbed power distribution 11 different from that based on the previous heating conditions can be generated. Therefore, by repeatedly updating the heating conditions until the object being heated 2 is given the necessary heat, a heating process with less heating unevenness can be performed.

[0108] exist Figure 9 In the heating control shown, based on reference Figures 2A to 4B The explanation describes how reflection variation is calculated using reflection characteristics obtained through frequency scanning. Besides frequency scanning, a reference frequency can also be used. Figures 7A-8 The phase scan is described. In this case, the heating conditions include frequency and phase difference. According to this method, an approximation of the absorbed power distribution 11 can be obtained.

[0109] In this embodiment, the oscillation unit 3 may generate high-frequency power of a certain frequency without performing frequency scanning, or it may have a structure that can only output a single frequency. In this case, the amplitude of reflection variation can be calculated based on the reflection characteristics obtained only through phase scanning and compared with a threshold, thereby determining the approximation of the absorbed power distribution 11.

[0110] As described above, according to this embodiment, various heated objects can be heated optimally.

[0111] By storing all the heating conditions used in the storage unit 8, the control unit 7 can avoid repeatedly using heating conditions that produce the same or similar power absorption distribution 11.

[0112] The reflection characteristic 9 and the reflection variation amplitude 12 change continuously rather than discontinuously. Therefore, the control unit 7 can also store only, for example, the maximum and minimum values ​​of the change, i.e., the reflection characteristic 9 representing the extreme values ​​of the change, in the storage unit 8. In this case, the control unit 7 can also reproduce the original data by appropriately interpolating the stored data.

[0113] As described above, by selecting a frequency from the frequency band where the reflection variation amplitude 12 is close to 0 as the heating condition, it is possible to change the distribution of absorbed power without increasing the reflected power. That is, the heating conditions used thereafter are determined to avoid the frequency band where the reflection variation amplitude 12 is large.

[0114] Based on this principle, heating conditions to be used next can also be determined using methods different from those described above. For example, control unit 7 can calculate the maximum value of reflection variation amplitude 12 for each frequency and store these maximum values ​​in storage unit 8. Control unit 7 can also refer to these maximum values ​​each time reflection variation amplitude 12 is calculated, and determine the frequency band with smaller reflection variation amplitude 12 as the heating condition to be used next.

[0115] Alternatively, the control unit 7 may calculate the cumulative value of the reflection variation amplitude 12 at each frequency obtained each time, and store these cumulative values ​​in the storage unit 8. The control unit 7 may also refer to the cumulative value each time the reflection variation amplitude 12 is calculated, and determine the frequency band with the smaller reflection variation amplitude 12 as the heating condition to be used next.

[0116] The control unit 7 can also use other heating conditions before determining the heating conditions to be used next.

[0117] Industrial availability

[0118] As described above, the high-frequency processing device disclosed herein can be applied not only to heating cookers using induction heating, but also to drying devices, ceramic heating devices, municipal solid waste processors, semiconductor manufacturing devices, chemical reaction devices, etc.

[0119] Explanation of reference numerals in the attached figures

[0120] 1: Heating chamber; 2: Object to be heated; 2a: Thawed meat; 2b: Frozen meat; 3: Oscillating section; 4a, 4b: Amplification section; 5a, 5b: Power supply section; 6a, 6b: Detection section; 7: Control section; 8: Storage section; 9: Reflection characteristics; 9A, 9B: Reflection characteristic curves; 10: Phase adjustment section; 11: Absorbed power distribution; 12: Reflection variation amplitude; 13: Similar heating conditions.

Claims

1. A high-frequency treatment apparatus, comprising, The high-frequency processing device includes: The heating chamber is configured to house the object to be heated. The oscillation section is capable of operating in such a way as to generate high-frequency power with any frequency within a specified frequency band; At least one power supply unit is capable of operating in such a way as to supply incident power based on the high-frequency power to the heating chamber; The detection unit is capable of operating in the following manner: detecting the incident electricity and the reflected electricity returning from the heating chamber to the at least one power supply unit; and Control Department The control unit is capable of operating in such a way that it causes the oscillation unit to perform a frequency scan and measures the reflection characteristics based on the incident power and the reflected power for each heating condition including the frequency. The control unit can operate in such a way that it determines the next heating condition to be used based on the frequency at which the value of the reflection variation amplitude, representing the change in the reflection characteristic, for each heating condition approaches 0, wherein the reflection variation amplitude is the difference between the two reflection characteristics before and after heating.

2. The high-frequency processing apparatus according to claim 1, wherein, The high-frequency processing device also includes a phase adjustment unit. The at least one power supply unit includes a first power supply unit and a second power supply unit. The phase adjustment unit is connected to the oscillation unit and can operate in the following manner: adjusting the phase difference between the high-frequency power to be supplied by the first power supply unit and the high-frequency power to be supplied by the second power supply unit. The control unit is capable of operating in such a way that the phase adjustment unit performs a phase scan and measures the reflection characteristics based on the incident power and the reflected power for each heating condition that also includes the phase difference.

3. The high-frequency processing apparatus according to claim 1, wherein, The control unit can operate in such a way that it determines the heating condition in which the absolute value of the reflection variation amplitude is less than a threshold as the heating condition to be used next.

4. The high-frequency processing apparatus according to claim 3, wherein, The threshold is a value obtained by multiplying the absolute value of the reflection variation amplitude by a specified coefficient.

5. The high-frequency processing apparatus according to claim 1, wherein, The high-frequency processing device also includes a storage unit. The control unit is capable of operating in such a way that it stores the reflection characteristics in the storage unit each time the heating conditions to be used next are determined.

6. The high-frequency processing apparatus according to claim 5, wherein, The control unit can operate in the following manner: each time the reflection variation amplitude is calculated, the maximum value of the reflection variation amplitude is calculated, the maximum value is stored in the storage unit, and the heating conditions to be used next are determined based on the maximum value.

7. The high-frequency processing apparatus according to claim 5, wherein, The control unit can operate in the following manner: each time the reflection variation amplitude is calculated, a cumulative value of the reflection variation amplitude is calculated, the cumulative value is stored in the storage unit, and the heating conditions to be used next are determined based on the cumulative value.

8. The high-frequency processing apparatus according to claim 5, wherein, The control unit can operate in such a way that it replaces the value of the reflection variation amplitude under each heating condition with a value having a different sign than the value of the reflection variation amplitude under the same heating condition as the past heating condition with 0.

9. The high-frequency processing apparatus according to claim 2, wherein, The frequency scan is an action of changing the frequency at uniform or non-uniform intervals throughout the specified frequency band, and the phase scan is an action of changing the phase difference at uniform or non-uniform intervals throughout the specified angular range.

10. The high-frequency processing apparatus according to claim 5, wherein, The control unit can operate in such a way that the storage unit stores only the reflection characteristics that exhibit varying extreme values.

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