阅读说明：本技术 解冻装置以及解冻方法 (Thawing device and thawing method ) 是由 上田雅哉 于 2019-06-26 设计创作，主要内容包括：本发明的解冻装置在适当的时刻使物体的解冻停止。温度测量器(18)测量匹配电路(13)或高频电源(11)的温度。控制部(21)基于所测量的温度,控制对物体(22)的无线电波的照射和停止。(The thawing apparatus of the present invention stops thawing of an object at an appropriate timing. A temperature measuring device (18) measures the temperature of the matching circuit (13) or the high-frequency power supply (11). A control section (21) controls irradiation and stop of radio waves to the object (22) based on the measured temperature.)

1. A thawing apparatus, characterized by comprising:

a housing storing an object that has been frozen;

a high-frequency power supply that generates high-frequency power;

a matching circuit that adjusts the high-frequency power generated by the high-frequency power supply to a matched high-frequency power;

an electrode that is disposed within the case and irradiates a radio wave to the object by using the high-frequency power that has been matched;

a temperature measuring device that measures a temperature of the matching circuit or the high-frequency power supply; and

a control section that controls irradiation and stop of the radio wave to the object based on the measured temperature.

2. Thawing apparatus according to claim 1,

the temperature measurer measures the temperature during the irradiation of the radio wave,

the control portion stops the irradiation of the radio wave in a case where the measured temperature exceeds a prescribed threshold value.

3. Thawing apparatus according to claim 1,

the temperature measurer measures the temperature before and during the irradiation of the radio wave, respectively,

the control portion stops the irradiation of the radio waves in a case where a difference between the measured temperatures exceeds a prescribed threshold value.

4. Thawing apparatus according to claim 1,

the temperature measurer measures the temperature before and during the irradiation of the radio wave, respectively,

the control portion stops the irradiation of the radio wave in a case where a rate of rise of the measured temperature exceeds a prescribed threshold value.

5. Thawing apparatus according to claim 1,

the temperature measurer measures the temperature before and during the irradiation of the radio wave, respectively,

the control portion calculates a heat dissipation amount by integrating a difference between the measured temperatures and an irradiation time of the radio wave, and stops irradiation of the radio wave when the calculated heat dissipation amount exceeds a prescribed threshold value.

6. Thawing apparatus according to claim 2,

the control portion stops the irradiation of the radio waves by causing the high-frequency power supply to stop the generation of the high-frequency power.

7. Thawing apparatus according to claim 1 or 2,

the temperature measurer is a thermistor.

8. Thawing apparatus according to claim 1 or 2,

further comprising a heat sink mounted on the matching circuit or the high frequency power supply,

the temperature measurer is mounted on the heat sink, and measures the temperature of the matching circuit or the high-frequency power supply by measuring the temperature of the heat sink.

9. Thawing apparatus according to claim 1 or 2,

the frequency of the high-frequency power is 3MHz to 300 MHz.

10. A thawing method, characterized in that the thawing apparatus of claim 1 is used to thaw frozen objects.

Technical Field

The present invention relates to a thawing apparatus and a thawing method for thawing an object such as frozen food.

Background

Conventionally, thawing apparatuses using microwaves are generally used for thawing frozen food and other objects. The absorption of microwaves by water is much greater than that of microwaves by ice. Therefore, if a certain portion of the frozen product is rapidly melted during thawing, the degree of microwave absorption of the portion is sharply increased. As a result, the thawing of the portion is further promoted, thereby accelerating the overheating of the portion. This phenomenon is called Runaway (Runaway) and results in the object being unevenly thawed by the microwaves. If runaway occurs, the temperature of the surface of the object will be different from the temperature of the interior. Thus, it is difficult to determine whether or not the object has been appropriately thawed without damaging the object.

In addition, conventionally, a thawing apparatus that uses radio waves instead of microwaves to thaw an object has been proposed. The depth to which a radio wave or microwave penetrates an object is inversely proportional to its frequency. Therefore, the radio waves are more capable of heating the inside of the object than the microwaves. Further, since the difference in the degree of absorption of radio waves between water and ice is smaller compared to microwaves, there is an advantage of suppressing partial thawing of an object in the case of thawing by radio waves.

Patent document 1 discloses a radio wave thawing apparatus having: an electrode; a high frequency power supply for supplying power to the electrode; a reflected power detection unit that is provided at an output of the high-frequency power supply and detects power reflected from the electrode side; and a display unit that receives the output of the reflected power detection unit and performs a display operation. Patent document 1 also discloses that according to this apparatus, the user can be appropriately notified of the operating state of the radio wave thawing apparatus.

Disclosure of Invention

Technical problem to be solved by the invention

However, in the technique disclosed in patent document 1, the user of the radio wave thawing apparatus needs to judge the stop of thawing based on his own experience. Therefore, it is difficult to accurately determine the stop of thawing, and as a result, it is also difficult to stop thawing of the object at an appropriate timing.

An object of an aspect of the invention is to stop the thawing of the object at a suitable moment.

Means for solving the problems

(1) One embodiment of the present invention is a thawing apparatus, comprising: a housing storing an object that has been frozen; a high-frequency power supply that generates high-frequency power; a matching circuit that adjusts the high-frequency power generated by the high-frequency power supply to a matched high-frequency power; an electrode that is disposed within the case and irradiates a radio wave to the object by using the high-frequency power that has been matched; a temperature measuring device that measures a temperature of the matching circuit or the high-frequency power supply; and a control section that controls irradiation and stop of the radio wave to the object based on the measured temperature.

(2) Further, in the thawing apparatus according to an embodiment of the present invention, in addition to the configuration of (1), the temperature measuring device measures the temperature during irradiation of the radio waves, and the control section stops the irradiation of the radio waves when the measured temperature exceeds a predetermined threshold value.

(3) Further, the thawing apparatus according to an embodiment of the present invention is the thawing apparatus according to the configuration of (1), wherein the temperature measuring unit measures the temperatures before and during the irradiation of the radio waves, respectively, and the control unit stops the irradiation of the radio waves when a difference between the measured temperatures exceeds a predetermined threshold value.

(4) In the thawing apparatus according to an embodiment of the present invention, in addition to the configuration of (1), the temperature measuring unit measures the temperature before the irradiation of the radio waves and during the irradiation of the radio waves, respectively, and the control unit stops the irradiation of the radio waves when a rate of increase of the measured temperature exceeds a predetermined threshold value.

(5) The thawing apparatus according to an embodiment of the present invention is the thawing apparatus according to the configuration of (1), wherein the temperature measuring unit measures the temperatures before and during the irradiation of the radio waves, respectively, and the control unit calculates a heat radiation amount by integrating a difference between the measured temperatures and an irradiation time of the radio waves, and stops the irradiation of the radio waves when the calculated heat radiation amount exceeds a predetermined threshold.

(6) In the thawing apparatus according to an embodiment of the present invention, in addition to any one of the configurations (2) to (5), the control unit may stop the irradiation of the radio waves by stopping the generation of the high-frequency power by the high-frequency power supply.

(7) In the thawing apparatus according to an embodiment of the present invention, in addition to the configuration of any one of the above (1) to (6), the temperature measuring device is a thermistor.

(8) A thawing apparatus according to an embodiment of the present invention further comprises a heat sink attached to the matching circuit or the high-frequency power supply, in addition to the configuration of any one of (1) to (7), wherein the temperature measuring device is attached to the heat sink and measures the temperature of the matching circuit or the high-frequency power supply by measuring the temperature of the heat sink.

(9) In the thawing apparatus according to an embodiment of the present invention, in addition to the configuration of any one of the above (1) to (8), the frequency of the high-frequency power is 3MHz or more and 300MHz or less.

(10) A thawing method according to an embodiment of the present invention is a thawing method for thawing a frozen object using the thawing apparatus according to any one of the items (1) to (5).

Effects of the invention

According to an aspect of the present invention, it is possible to stop the thawing of the object at an appropriate timing.

Drawings

Fig. 1 is a block diagram showing a configuration of a main part of a thawing apparatus according to a first embodiment of the present invention.

Fig. 2 is a diagram showing a circuit configuration of a matching circuit according to a first embodiment of the present invention.

Fig. 3 is a diagram showing a circuit configuration of a thermistor constituting a temperature measuring instrument according to a first embodiment of the present invention.

Fig. 4 is a diagram showing a time transition of the high-frequency power output from the high-frequency power supply and a time transition of the reflected wave power, respectively, according to the first embodiment of the present invention.

Fig. 5 is a loss factor representing the degree of absorption of microwaves and radio waves in water and ice.

Fig. 6 is a block diagram showing a configuration of a main part of a thawing apparatus according to a second embodiment of the present invention.

Fig. 7 is a graph showing the measurement result of the temperature of the high-frequency power supply acquired by the temperature measurer as the thermal imager according to the second embodiment of the present invention.

Fig. 8 is a block diagram showing a configuration of a main part of a thawing apparatus according to a third embodiment of the present invention.

Detailed Description

[ first embodiment ]

(constitution of thawing apparatus 1)

Fig. 1 is a block diagram showing a main part configuration of a thawing apparatus 1 according to a first embodiment of the present invention. As shown, the thawing apparatus 1 comprises: a high-frequency power source 11, a heat sink 12, a matching circuit 13, a heat sink 14, a case 15, a pair of electrodes 16 and 17, a temperature measuring device 18, a circulator 19, a detecting unit 20, and a control unit 21. The thawing apparatus 1 is an apparatus that thaws the object 22 by irradiating radio waves to the frozen object. The object 22 is for example a frozen food product.

The high-frequency power supply 11 generates high-frequency power using power input from the outside of the thawing apparatus 1. The high-frequency power supply 11 supplies the generated high-frequency power to the matching circuit 13. In the present embodiment, "radio wave" means an electric signal or a radio wave (electromagnetic wave) of 100kHz or more and 300MHz or less. The frequency of the high-frequency power generated by the high-frequency power source 11 is preferably 3MHz or more and 300MHz or less. Thereby, the thawing apparatus 1 can irradiate the object 22 with radio waves that can appropriately heat the object 22. In the present embodiment, the high-frequency power supply 11 generates high-frequency power having a frequency of 40 MHz.

The heat sink 12 is mounted to the high-frequency power supply 11. The heat sink 12 cools and physically protects the high-frequency power supply 11. The shape of the heat sink 12 is, for example, a fin shape, a simple block shape or a special shape suitable for the high-frequency power source 11. The material of the heat sink 12 is preferably metal. The material of the heat sink 12 may be a material other than metal as long as it has a function of conducting heat generated by the high-frequency power source 11. The heat capacity of the heat sink 12 is preferably known in advance, regardless of the shape and material of the heat sink 12. Thus, the control unit 21 can calculate the amount of heat absorbed by the radiator 12 more accurately using the temperature measured by the temperature measuring device 18.

The matching circuit 13 adjusts the high-frequency power supplied from the high-frequency power supply 11 to the matched high-frequency power. The matching circuit 13 supplies the matched high-frequency power to the electrode 16.

Fig. 2 is a diagram showing a circuit configuration of the matching circuit 13 according to the first embodiment of the present invention. Since the circuit configuration of the matching circuit 13 shown in the figure is known, detailed description thereof is omitted.

The heat sink 14 is mounted to the matching circuit 13. The heat sink 14 cools and protects the matching circuit 13. The shape of the heat sink 14 is, for example, a heat-radiating fin shape, a simple block shape or a special shape suitable for the matching circuit 13. The material of the heat sink 14 is preferably metal. The material of the heat sink 14 may be a material other than metal as long as it has a function of conducting heat generated by the matching circuit 13. The heat capacity of the heat sink 14 is preferably known in advance, regardless of the shape and material of the heat sink 14. Thus, in the first embodiment described later, the temperature measuring device 18 can more accurately measure the amount of heat absorbed by the radiator 14.

The case 15 stores an object 22 thawed by the thawing apparatus 1 in the inside thereof. The housing 15 also prevents radio waves from leaking to the outside of the housing 15. The pair of electrodes 16 and 17 are provided inside the case 15. The object 22 is arranged inside the housing 15 between the electrodes 16 and 17. Electrode 16 is connected to matching circuit 13 and electrode 17 is connected to ground. High-frequency power is supplied from the matching circuit 13 to the electrode 16. The electrodes 16 and 17 form a radio wave electric field by using high-frequency power supplied to the electrode 16, and irradiate an object 22 with a radio wave (radio wave) according to the formed electric field. The object 22 is thawed by the irradiated radio waves. The electrode 16 transmits to the matching circuit 13 as reflected wave power by reflecting a part of the supplied high frequency power.

(temperature measuring instrument 18)

The temperature measuring device 18 is mounted on the heat sink 14. The temperature measurer 18 measures the amount of heat radiation, which is the amount of heat released from the entire matching circuit 13, by measuring the temperature of the heat sink 14 having a known heat capacity. In this way, the temperature measuring device 18 indirectly measures the temperature of the matching circuit 13 by measuring the temperature of the heat sink 14. In the present embodiment, the temperature measuring device 18 is a thermistor having a simpler structure and use. The temperature measuring device 18 converts the measured temperature of the heat sink 14 into an analog electric signal and outputs the signal to the control unit 21.

Fig. 3 is a diagram showing the configuration of a temperature detection circuit using a thermistor constituting temperature measuring instrument 18 according to the first embodiment of the present invention. Since the circuit configuration of the temperature detection circuit shown in fig. 3 is known, a detailed description thereof is omitted.

The temperature measurer 18 may be directly mounted to the matching circuit 13 instead of the heat sink 14. The temperature measurer 18 is mounted on, for example, a coil of the matching circuit 13. In this case, the temperature measurer 18 measures the temperature of a part of the matching circuit 13 by measuring the temperature of the coil.

The circulator 19 is disposed between the high-frequency power supply 11 and the matching circuit 13. The circulator 19 reduces the reflected wave power transmitted from the electrode 16 and the matching circuit 13 to the circulator 19, and transmits the reflected wave power to the detection section 20. The detection unit 20 detects the reflected wave power transmitted from the circulator 19. The detection unit 20 generates information on the amount of the detected reflected wave power, and outputs the information to the control unit 21. The thawing apparatus 1 does not necessarily need the detection section 20 and the circulator 19.

(control section 21)

The control unit 21 comprehensively controls the operation of the thawing apparatus 1. The control section 21 is connected to at least the high-frequency power supply 11, the matching circuit 13, the detection section 20, and the temperature measuring instrument 18. The control section 21 controls the operation and stop of the high-frequency power supply 11 mainly based on the temperature measured by the temperature measuring instrument 18. The control unit 21 may also control the output value of the high-frequency power from the high-frequency power supply 11. The control section 21 may also control the matching degree of the high-frequency power by the matching circuit 13. The control section 21 may also perform feedback control of the high-frequency power supply 11 and the matching circuit 13 based on information on the amount of reflected wave power input from the detection section 20.

In the present embodiment, the control unit 21 is a microcontroller having a plurality of terminals. An analog electric signal representing the temperature output from the matching circuit 13 is input to a specific terminal among the plurality of terminals. The control section 21 obtains a digital value indicating temperature by analog-to-digital converting an analog electric signal input to a specific terminal. The control unit 21 determines the timing of stopping the thawing of the object 22 by using the acquired digital value.

(thawing step of object 22)

The thawing apparatus 1 starts the thawing of the object 22 and determines the stop of the thawing according to the steps described below.

The user of the thawing apparatus 1 inputs an instruction or operation to start thawing of the object 22 to the control unit 21. The control section 21 forms radio waves on the electrodes 16 and 17 and irradiates radio waves to the object 22 by controlling the high-frequency power supply 11 and the matching circuit 13. Thereby, thawing of the object 22 is started. In the present embodiment, the user may simply input an instruction to start thawing to the thawing apparatus 1. Alternatively, the user may input conditions such as the mass of the object 22, the temperature of the object 22 before thawing, the target temperature of the object 22 after thawing, and the amount of high-frequency power to the control unit 21 together with an instruction to start thawing.

When radio waves are irradiated to the object 22, ice contained in the object 22 is converted into water by the radio waves. Since the radio waves penetrate deeper into the object 22 than the microwaves, the object 22 irradiated with the radio waves is uniformly thawed. The difference between the absorbance of water and the absorbance of ice is smaller for radio waves than for microwaves. Therefore, a phenomenon in which a part of the object 22 melts earlier during thawing is suppressed.

The temperature measurer 18 measures the temperature of the matching circuit 13 at least during the irradiation of the radio wave. As the thawing of the object 22 is performed by the radio wave irradiation, the temperature of the matching circuit 13 rises. The temperature measuring device 18 transmits the measured temperature to the control section 21. The control section 21 determines whether or not to stop the defrosting of the object 22 based on the temperature transmitted from the temperature measurer 18. The control unit 21 determines to stop thawing of the object 22 when detecting that the temperature has increased, for example, based on the temperatures transmitted at different times. Thereby, the control unit 21 controls the high-frequency power supply 11 to stop the generation of the high-frequency power. As a result, thawing of the object 22 is stopped.

The temperature measurer 18 measures the temperature of the matching circuit 13 during irradiation of radio waves, for example. In this case, when the measured temperature exceeds a prescribed threshold, the control section 21 causes the high-frequency power supply 11 to stop the generation of the high-frequency power, thereby stopping the irradiation of the radio wave to the object 22. Thereby, the control unit 21 can stop thawing of the object 22 at an appropriate timing. The threshold value of the predetermined temperature may be a value stored in the control unit 21 in advance. The control unit 21 may calculate the temperature threshold value by using conditions input to the control unit 21 by the user, such as the mass of the object 22, the temperature of the object 22 before thawing, the target temperature of the object 22 after thawing, and the amount of high-frequency power.

The temperature measurer 18 measures the temperature of the matching circuit 13, for example, before and during the irradiation of radio waves, respectively. The control unit 21 calculates a temperature difference by subtracting the temperature before irradiation from the temperature during irradiation. When the calculated temperature difference exceeds a prescribed threshold, the control section 21 stops the high-frequency power supply 11 from generating the high-frequency power, thereby stopping the irradiation of the radio wave. Thereby, the control unit 21 can stop thawing of the object 22 at an appropriate timing. The threshold value of the predetermined temperature difference may be a value stored in the control unit 21 in advance. The control unit 21 may calculate the threshold value of the temperature difference by using the conditions input by the user to the control unit 21, such as the mass of the object 22, the temperature of the object 22 before thawing, the target temperature of the object 22 after thawing, and the amount of high-frequency power.

The temperature measurer 18 measures the temperature of the matching circuit 13, for example, before and during the irradiation of radio waves, respectively. The control unit 21 calculates a temperature difference by subtracting the temperature before irradiation from the temperature during irradiation. The control section 21 calculates the rate of rise of the temperature by dividing the calculated temperature difference by the measurement time interval for each temperature. When the calculated temperature increase rate exceeds a predetermined threshold, the control section 21 stops the high-frequency power supply 11 from generating the high-frequency power, thereby stopping the irradiation of the radio wave. Thereby, the control unit 21 can stop thawing of the object 22 at an appropriate timing. The threshold value of the predetermined rising speed may be a value stored in the control unit 21 in advance. The control unit 21 may calculate the threshold value of the rising speed by using the conditions input to the control unit 21 by the user, such as the mass of the object 22, the temperature of the object 22 before thawing, the target temperature of the object 22 after thawing, and the electric power amount of the high-frequency power.

The temperature measurer 18 measures the temperature of the matching circuit 13, for example, before and during the irradiation of radio waves, respectively. The control unit 21 calculates a temperature difference by subtracting the temperature before irradiation from the temperature during irradiation. The control section 21 integrates the calculated temperature difference with the irradiation time of the radio wave to calculate the amount of heat released from the matching circuit 13, that is, the amount of heat radiation. When the calculated amount of heat radiation exceeds a prescribed threshold, the control section 21 stops the high-frequency power supply 11 from generating high-frequency power, thereby stopping the irradiation of radio waves. Thereby, the control unit 21 can stop thawing of the object 22 at an appropriate timing. The predetermined threshold value of the amount of heat radiation may be a value stored in the control unit 21 in advance. The control unit 21 may calculate the threshold value of the heat dissipation amount by using the conditions input to the control unit 21 by the user, such as the mass of the object 22, the temperature of the object 22 before thawing, the target temperature of the object 22 after thawing, and the amount of electric power of the high-frequency power.

(cause of temperature rise of matching circuit 13)

In the thawing apparatus 1, the cause of the temperature rise of the matching circuit 13 as the thawing of the object 22 progresses is not clear. The inventors of the present application inferred that the reason is as follows. When the ice contained in the object 22 turns into water, the resistance of the object 22 becomes small. High-frequency power is supplied from the high-frequency power source 11 to the matching circuit 13 and the object 22. When only the resistance value of the object 22 becomes small during the supply of the high-frequency power, the load of the high-frequency power to the matching circuit 13 becomes large, resulting in generation of energy loss in the matching circuit 13. The energy loss is converted into heat energy, whereby the temperature of the matching circuit 13 rises. As described above, when the temperature of the matching circuit 13 rises, the thawing apparatus 1 determines that the thawing of the object 22 is completed, and stops the thawing of the object 22.

Fig. 4 is a diagram showing a time transition of the high-frequency power output from the high-frequency power supply and a time transition of the reflected wave power, respectively, according to the first embodiment 11 of the present invention. The horizontal axis of fig. 4 represents the elapsed time after the electrode 16 irradiates the object 22 with radio waves. The left vertical axis of fig. 4 represents the intensity of the high-frequency power output from the high-frequency power supply 11. The right vertical axis of fig. 4 represents return loss. The return loss is a value obtained by expressing a ratio between the reflected wave power and the traveling wave (high-frequency power) in a logarithmic manner.

When the object 22 is thawed by radio waves, the impedance of the object 22 changes as thawing progresses. Fig. 4 shows the result of measuring the temporal changes of the high-frequency power and the reflected-wave power when impedance matching between the high-frequency power source 11 and the object 22 is performed by the matching circuit 13 during radio-wave irradiation of the object 22. From fig. 4, it can be seen that the reflected wave power increases as the object 22 is further thawed after impedance matching. From this, the following is inferred. When the ice contained in the object 22 turns into water, the impedance of the object 22 changes. A high-frequency power supply is supplied from the high-frequency power supply 11 to the matching circuit 13 and the object 22, and when only the impedance of the object 22 changes during the supply, the reflected wave power transmitted to the matching circuit 13 increases. The reflected wave circuit is converted into heat according to the high frequency power supply 11, the parasitic capacitance, the parasitic inductance, and the like in the matching circuit 13 or its periphery. The temperature measurer 18 measures the temperature of the matching circuit 13 by detecting the heat.

Fig. 5 is a loss factor representing the degree of absorption of microwaves and radio waves in water and ice. The characteristics of a dielectric are represented by a dielectric constant and a dielectric power factor. The loss factor is the product of the dielectric constant and the dielectric power factor. The loss factor is a reference for ease of heating in an object heated by an electric wave. The loss factor fluctuates according to the frequency of the electric wave irradiated to the object and the temperature of the object 22. The amount of heat generated by the object is proportional to the frequency of the irradiated electric wave and the loss factor of the object, and inversely proportional to the square of the electric field intensity. On the other hand, the depth at which the electric wave penetrates the inside of the object is inversely proportional to the frequency of the electric wave. Therefore, it is more advantageous to use radio waves having a frequency less than that of microwaves in order to uniformly thaw an object.

As shown in fig. 5, the respective dielectric losses of water and ice are much larger in water than in ice when irradiated with microwaves. Thus, in the related art in which an object is thawed by microwaves, when ice contained in a portion of the object melts and becomes water, a loss factor of the portion significantly changes, and thus the change of microwaves absorbed by the object is very rapid. Therefore, in the related art, it is difficult to detect the temperature of the matching circuit by using a thermistor having a slow temperature detection speed.

As shown in fig. 5, the difference between the respective dielectric losses of water and ice in the case of irradiation with radio waves is sufficiently small as compared with the case of irradiation with microwaves. Thus, in the thawing apparatus 1 that thaws the object 22 by radio waves, when ice contained in a portion of the object 22 melts and becomes water, the loss factor of the portion changes gently. Further, the depth of the radio wave penetrating into the inside of the object 22 is inversely proportional to the frequency of the radio wave. Therefore, the change of the radio wave absorbed by the object 22 is gentle compared to the microwave. From these findings, the thawing apparatus 1 can measure the temperature of the matching circuit 13 by using a thermistor as the temperature measuring device 18, which is slow in temperature detection speed but inexpensive.

As shown in fig. 3, the thermistor has a small number of parts even if a peripheral portion is included. Therefore, the thermistor can be configured at low cost. Since the thawing apparatus 1 is equipped with an inexpensive thermistor as the temperature measuring device 18, the cost of the thawing apparatus 1 can be reduced.

As described above, the thawing apparatus 1 can stop the thawing of the object 22 at an appropriate timing by an inexpensive apparatus.

[ second embodiment ]

Fig. 6 is a block diagram showing a configuration of a main part of the thawing apparatus 2 according to the second embodiment of the present invention. As shown in the drawing, the thawing apparatus 2 includes the same components as those provided in the thawing apparatus 1 according to the first embodiment. However, the thawing apparatus 2 is different from the thawing apparatus 1 according to the first embodiment in that the temperature measurer 18 is mounted to the radiator 12 instead of the radiator 14. In the thawing apparatus 2, the temperature measurer 18 measures the heat, which is the heat released from the entire high-frequency power source 11, by measuring the temperature of the heat sink 12 having a known heat capacity. In this way, the temperature measuring device 18 indirectly measures the temperature of the high-frequency power supply 11 by measuring the temperature of the heat sink 12.

The temperature measurer 18 may be directly mounted to the high-frequency power supply 11 instead of the heat sink 12. The temperature measuring device 18 is attached to, for example, a coil of the high-frequency power supply 11. In this case, the temperature measurer 18 measures the temperature of a part of the high-frequency power supply 11 by measuring the temperature of the coil of the high-frequency power supply 11.

In the thawing apparatus 2, when only the resistance value of the object 22 becomes small by the irradiation of the radio wave, the reflected wave power transmitted to the high frequency power via the circulator 19 also increases. The reflected wave power is converted into heat in the high-frequency power, and the temperature measuring device 18 measures the temperature of the high-frequency power supply 11 by detecting the heat. The temperature measuring device 18 transmits the measured temperature of the high-frequency power source 11 to the control unit 21. The control unit 21 determines the timing of stopping the thawing of the object 22 based on the transmitted temperature.

The temperature measurer 18 may also be a thermal imager instead of a thermistor. The temperature measurer 18 can also accurately measure the temperature of the high-frequency power supply 11 in this case. Fig. 7 is a graph showing the measurement result of the temperature of the high-frequency power supply 11 acquired by the temperature measurer as the thermal imager according to the second embodiment of the present invention. When the temperature measurer 18 is a thermal imager, the temperature measurer 18 acquires a measurement result of the temperature (thermal imaging map) as shown in fig. 7, for example, and outputs it to the control section 21. The control section 21 controls the irradiation and stop of radio waves based on the thermal imaging map input from the temperature measurer 18.

The method of determining the timing at which the thawing of the object 22 is stopped by the control section 21 according to the present embodiment is basically the same as the method disclosed in the first embodiment. Therefore, the control section 21 can appropriately determine the timing at which the thawing of the object 22 is stopped.

In the case where the thawing apparatus 2 does not include the circulator 19, the reflected wave power transmitted to the high-frequency power supply 11 is further increased. Therefore, the design according to the present embodiment is more effective for the thawing apparatus 1 not provided with the circulator 19.

[ third embodiment ]

Fig. 8 is a block diagram showing a configuration of a main part of the thawing apparatus 3 according to the third embodiment of the present invention. As shown in the drawing, the thawing apparatus 3 further includes a temperature measuring instrument 23 in addition to the respective members provided in the thawing apparatus 1 according to the first embodiment. In the thawing apparatus 3, the temperature measuring device 18 is attached to the heat sink 14, and the temperature measuring device 23 is attached to the heat sink 14. The control unit 21 is connected to at least the high-frequency power supply 11, the matching circuit 13, the temperature measuring device 18, the detection unit 20, and the temperature measuring device 23. As in the first embodiment, the temperature measuring device 18 indirectly measures the temperature of the matching circuit 13 by measuring the temperature of the heat sink 14. The temperature measuring device 23 indirectly measures the temperature of the high-frequency power supply 11 by measuring the temperature of the heat sink 14. The temperature measuring device 23 transmits the measured temperature to the control section 21.

The control section 21 controls the irradiation and stop of the radio wave to the object 22 based on both the temperature of the matching circuit 13 measured by the temperature measurer 18 and the temperature of the high-frequency power supply 11 measured by the temperature measurer 23. Thus, the control unit 21 can more accurately determine the timing of stopping the thawing of the object 22. The control section 21 calculates a first heat dissipation amount by, for example, integrating the temperature difference (temperature increase value) of the matching circuit 13 before and after the irradiation of the radio wave with the irradiation time. The control section 21 also calculates a second heat radiation amount by integrating the temperature difference (temperature increase value) of the high-frequency power supply 11 before and after the irradiation of the radio wave with the irradiation time. The control section 21 controls the irradiation and stop of the radio waves based on the total heat radiation amount, which is a value obtained by adding the first heat radiation amount and the second heat radiation amount. The control unit 21 can thereby determine the time at which thawing is stopped more accurately. For example, in the case where the total heat radiation amount exceeds a prescribed threshold value, the control section 21 stops the irradiation of radio waves from the electrode 16 by controlling the high-frequency power supply 11. As a result, the object 22 is more appropriately thawed.

The present disclosure is not limited to the above embodiments, and various modifications can be made within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention. Further, new technical features can be formed by combining the technical methods disclosed in the respective embodiments.

Description of the reference numerals

1. 2, 3 thawing device

11 high frequency power supply

12. 14 radiator

13 matching circuit

15 casing

16. 17 electrode

18. 23 temperature measuring device

19 circulation device

20 detection part

21 control part

22 object