JP2003217819A - Vacuum microwave defrosting machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform suitable control by deciding that the discharge generated in a chamber is the discharge generated in the chamber. <P>SOLUTION: While the process of reducing the pressure in the chamber and the process of restoring the pressure in the chamber are alternately performed, microwaves are radiated in the chamber to thereby defrost a material to be defrosted. In the pressure restoring process, when discharge is detected two or more times by a discharge sensor (R" points) at least radiation of microwaves is ended. In this pressure restoring process, when the discharge is detected two or more times by the discharge sensor, it is considered that the discharge is caused despite of gradual decrease in the degree of pressure reduction in the chamber, so the occurrence of discharge in the chamber can be decided. According to this decision, at least the radiation of microwaves is ended, whereby the discharge in the chamber is prevented not to damage the chamber. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum microwave defroster for thawing an object to be thawed such as frozen food by irradiating it with microwaves under reduced pressure.

[0002]

2. Description of the Related Art Conventionally, a vacuum microwave defroster is provided with a chamber for containing an object to be defrosted, a vacuum pump for decompressing the chamber, a recompression valve for decompressing the chamber, and a chamber. A microwave generator for generating a microwave to be irradiated is provided, and by performing a process of decompressing the chamber and a process of decompressing the chamber alternately, by irradiating the chamber with a microwave, The object to be thawed is thawed.

The advantage of the vacuum microwave defroster for defrosting the object to be thawed in this way is that the sublimation (from solid to gas) of the surface portion of the object to be thawed is promoted by the reduced pressure,
The temperature rise due to microwaves reaching the water (liquid) on the surface of the object to be thawed is suppressed, so that the surface part of the object to be thawed can be uniformly thawed without increasing the temperature.

However, in the case of this structure, electric discharge is apt to occur in the chamber due to irradiation with microwaves in a reduced pressure state. This discharge is generated in the object to be thawed and in the chamber. Among them, the discharge particularly generated in the chamber may damage the chamber and must be avoided. Therefore, in the conventional vacuum microwave defroster, a discharge sensor is provided, and when the occurrence of discharge in the chamber is detected by this, irradiation of microwaves is terminated, or the defrosting operation is performed entirely. The one that is supposed to be finished is provided.

[0005]

However, in the conventional case, it is not possible to judge whether the discharge generated in the chamber is generated in the object to be thawed or in the chamber. Therefore, the thaw operation is performed. In many cases, there were many cases where the irradiation of microwaves was terminated or the thaw operation was completely terminated, and the thaw operation was not completed normally.

The present invention has been made in view of the above circumstances, and therefore its purpose is mainly to determine that the discharge generated in the chamber is the one generated in the chamber, and to perform appropriate control. It is to provide a vacuum microwave defroster capable of

[0007]

In order to achieve the above object, a vacuum microwave defroster according to the present invention comprises a chamber for accommodating an object to be thawed, a decompression means for decompressing the inside of the chamber, and an inside of the chamber. A pressure reducing means for returning pressure, a microwave generator for generating microwaves for irradiating the chamber, and a discharge sensor for detecting discharge in the chamber, and a step of reducing the pressure in the chamber and the chamber thereof. While alternately performing the process of repressurizing the inside,
In the one provided with a control means for irradiating the inside of the chamber with microwaves to defrost the object to be defrosted, the control means, during the recompression process, when the discharge is detected by the discharge sensor a plurality of times, At least the irradiation of microwaves is terminated (the invention of claim 1).

As described above, in the vacuum microwave defroster, electric discharge is likely to occur in the chamber by irradiating the microwave under a reduced pressure. When the inventor investigated this discharge, in the region where the degree of reduced pressure is high, discharge is likely to occur in both the object to be thawed and the chamber, but as the degree of reduced pressure becomes smaller, the amount of object to be thawed decreases. However, it has been found that the discharge in the chamber does not decrease even when the degree of pressure reduction decreases.

Therefore, as described above, when the discharge sensor detects a plurality of discharges during the pressure recovery stroke, the discharge is generated even though the degree of pressure reduction is gradually reduced. It can be determined that discharge has occurred in the chamber, and in this situation, at least the irradiation of microwaves can be terminated to eliminate discharge in the chamber and prevent damage to the chamber. On the other hand, it is considered that discharge occurs on the object to be defrosted until the discharge sensor detects multiple discharges during the pressure recovery process.In this situation, the discharge sensor may subsequently detect discharge. If not, the thawing operation can be completed by continuing the thawing operation accompanied by microwave irradiation.

In this case, the control means temporarily stops only the microwave irradiation when the discharge is detected by the discharge sensor during the pressure recovery stroke, restarts the microwave irradiation thereafter, and further after that, It is preferable that the thawing operation is ended when the discharge is detected by the discharge sensor (the invention of claim 2). With this, the defrosting operation can be completed and the chamber can be prevented from being damaged by finer control.

Further, it is preferable that the control means stops only the microwave irradiation when the discharge is detected by the discharge sensor during the depressurization process (the invention of claim 3). When discharge is detected by the discharge sensor during the depressurization process, it can be determined that discharge is occurring in the thawed object depending on the type of the thawed object. Easier to do. Therefore, in this situation, only the microwave irradiation is stopped to eliminate the discharge of the object to be defrosted and continue the defrosting operation.

Further, when the control means terminates the thawing operation on the basis of the detection of the discharge by the discharge sensor, it is possible to have a notification means for notifying the outside of the thawing operation (the invention of claim 4). In this case, the end of the operation during the thawing operation,
It is easy for the user to understand.

In addition, the control means may have a check function for confirming the operation of the discharge sensor (the invention of claim 5). In this device, the discharge generated in the chamber can be detected after confirming the operation of the discharge sensor, so that the discharge can be detected more reliably. Further, the control means may confirm the operation of the discharge sensor before starting the microwave irradiation in the thawing operation (claim 6).
Invention). In this device, microwaves are emitted after confirming the operation of the discharge sensor, so that the discharge can be detected more reliably.

Further, it is preferable that the control means confirms the operation of the discharge sensor by the light of the inside lamp illuminating the inside of the chamber (the invention of claim 7). In this case, the operation of the discharge sensor can be confirmed by using the internal light that illuminates the inside of the chamber. Then, the control means may confirm the operation of the discharge sensor by the light outside the machine (the invention of claim 8). With this device, the operation of the discharge sensor can be confirmed using the light outside the machine.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below.
This will be described with reference to FIGS. 1 to 7. First, in FIG.
The whole of the vacuum microwave defroster is shown in a front view. A door 4 having a handle 3 is provided on an upper front portion of a cabinet 2 having a machine storage portion 1 at a lower portion thereof, and an operation portion 5 and a display portion 6 are provided at an upper portion thereof. And are provided. Of these, the operation unit 5
The user has various operation keys 5a for various operations related to the operation of the vacuum microwave defroster.

The display unit 6 displays various kinds of displays relating to the operation of the vacuum microwave defroster, and in this case, it has a display 6a for digital display and various display lamps 6b. An abnormal display lamp exists in the display lamp 6b. A plurality of casters 7 are provided on the outer lower surface of the bottom of the cabinet 2.

Next, FIG. 4 shows a chamber 8 disposed in the upper part of the inside of the cabinet 2, which is composed of a pressure vessel made of metal, the inner wall of which has a structure capable of reflecting microwaves. Has become. Also, this chamber 8
Is open at the front, and the door 4 is opened and closed at the opening. Although not shown in detail, the door 4 has packing on the peripheral edge of the back surface, and in the closed state, the packing is pressed against the peripheral edge of the opening of the chamber 8 to hermetically seal the opening. It is supposed to be blocked.

A turntable 9 is provided on the inner bottom of the chamber 8. The turntable 9 is detachably attached to the upper end of a support shaft 10. The support shaft 10 vertically penetrates the bottom wall of the chamber 8 and is rotatably supported by a bearing 11, and the lower end is provided with a speed reducer. Output shaft 12 of the motor 12
It is connected to a. Therefore, the turntable 9 is rotationally driven by the motor 12 via the support shaft 10.

On the other hand, a vacuum pressure sensor 13, an internal lamp 14, an atmosphere opening valve 15 and a pressure adjusting valve 16 are provided above the chamber 8. Of these, the vacuum pressure sensor 13 functions as a pressure detection unit that detects the vacuum pressure in the chamber 8. Further, the inside lamp 14 is configured to illuminate the inside of the chamber 8 through a closed light-transmitting portion 17 formed on the upper wall of the chamber 8. The translucent portion 17 is configured to withstand a vacuum pressure in the chamber 8 described later and to block microwaves. The atmosphere opening valve 15 functions as an atmosphere opening means for opening the inside of the chamber 8 to the atmosphere, and the pressure adjusting valve 16 adjusts the vacuum pressure in the chamber 8, and in particular, the recompression pressure for returning the inside of the chamber 8 which has been decompressed as described later. It functions as a means.

At the back of the chamber 8 is a magnetron 18 which is a microwave generator for generating microwaves.
And a waveguide 19 for guiding the microwave generated by the magnetron 18 into the chamber 8, and the microwave is irradiated into the chamber 8.

Further, a vacuum pump 20 is connected to a lower portion of the back of the chamber 8 via a pressure reducing pipe 21 having a check valve 21a. This vacuum pump 20 is a chamber 8
The motor 2 functions as a pressure reducing means for reducing the pressure inside.
2 is driven. The vacuum pump 20, the drive motor 22 for the vacuum pump 20, the motor 12 for driving the turntable 9, and the like are installed in the machine storage unit 1.
It is stored in.

A discharge sensor 23 is provided above the back of the chamber 8. The discharge sensor 23 is used in the chamber 8
It is a discharge detecting means for detecting the discharge inside, and in this case, it is composed of an optical sensor for detecting the discharge by the discharge light, particularly an ultraviolet sensor capable of more reliably detecting the discharge light.

In contrast to the above, FIG. 5 shows a control device 24 as a control means for controlling the overall operation of the vacuum microwave defroster.
Is shown. The control unit 24 is composed of a microcomputer or the like, and an operation signal is input from the operation unit 5 via the operation input circuit 25, and a discharge detection signal is output from the discharge sensor 23 via the detection input circuit 26. The door opening / closing sensor 2 is provided to detect the opening / closing of the door 4 as well as the pressure detection signal from the vacuum pressure sensor 13 via the detection input circuit 27.
An open / close detection signal is input from 8 (not shown in detail) via a detection input circuit 29.

Then, the control device 24 controls the operation of the display section 6 through the display control circuit 30 based on those inputs and the control program stored in the ROM 24a in advance, and at the same time, the operation of the interior light 14 is performed. Is controlled via the lighting control circuit 31, and the operation of the buzzer 32 (also not shown in detail) is controlled via the ringing control circuit 33. Further, the controller 24 controls the motor 12 for driving the turntable via a drive control circuit 34, and controls the motor 22 for driving the vacuum pump via a drive control circuit 35, so that the magnetron 18 is controlled.
Are controlled via the drive control circuit 36, and the atmosphere opening valve 15 is controlled via the opening / closing control circuit 37, and the pressure regulating valve 16
Is controlled via the opening / closing control circuit 38.

Next, the operation of the above structure will be described. To defrost the object to be defrosted with the above configuration, first open the door 4. Then, the door open / close sensor 28 detects it and outputs a door open detection signal, so that the control device 24
Based on this, the inside lamp 14 is turned on to illuminate the inside of the chamber 8. At the same time, the control device 24 controls the interior lamp 14
Of the light is detected by the discharge sensor 23, and thereby the operation of the discharge sensor 23 is confirmed (check).
do. In this case, when it is determined that the discharge sensor 23 detects the light of the interior light 14, the discharge sensor 23 is determined to operate normally.

Now, with the door 4 thus opened,
The object to be thawed is placed on the turntable 9 in the chamber 8, and thus the chamber 8 holds the object to be thawed, and then the door 4 is closed (therefore, the interior lamp 14 is turned off). . Then, by operating the operation unit 5, the thawing operation is started.

Then, the control unit 24 first drives the vacuum pump 20 by operating the vacuum pump driving motor 22 with the atmosphere opening valve 15 and the pressure regulating valve 16 closed, and thereby the vacuum pump 20 is driven. The vacuum pump 20 sucks the air in the chamber 8 through the pressure-reducing conduit 21 to reduce the pressure in the chamber 8. Therefore, the atmospheric pressure in the chamber 8 is about 101 [kP] of the atmospheric pressure as shown by A in FIG.
a] (reference value: 760 [Torr]), the vacuum pump 20 is continuously driven until the atmospheric pressure A in the chamber 8 reaches the decompression equilibrium region B, and the decompression stroke is executed. This decompression process preliminarily thaws the object to be thawed.

The decompression equilibrium region is a region where the amount of decompression per unit time is extremely small, and the equilibrium pressure in this decompression equilibrium region fluctuates depending on the saturated vapor pressure in the chamber 8. The determination as to whether or not it has reached is made by the control device 24 based on the pressure detection signal from the vacuum pressure sensor 13.

After that, the controller 24 controls the vacuum pump 20.
The pressure regulating valve 16 is opened at a predetermined opening in a state in which is stopped. As a result, the atmospheric pressure in the chamber 8 rises from the decompression equilibrium region B and is restored as shown by C in FIG.
Until the atmospheric pressure C in the chamber 8 reaches the recompression upper limit value H {for example, about 6.7 [kPa] (reference value: 50 [Torr])}, the pressure regulating valve 16 is continuously opened to perform the recompression stroke. To be done.

Further, the lower limit value P1 (for example, about 1.3 [kPa] (reference value: 10 [Torr])) at which the atmospheric pressure C in the chamber 8 in this pressure recovery process generally does not cause vacuum discharge.
After the point E, the microwave irradiation from the magnetron 18 into the chamber 8 is started. The control device 24 also makes a determination based on the pressure detection signal from the vacuum pressure sensor 13 whether or not the above-mentioned return pressure upper limit value H has been reached.

After that, the control device 24 operates the vacuum pump driving motor 22 again with the pressure regulating valve 16 closed, thereby driving the vacuum pump 20 and executing the decompression stroke. Then, until the atmospheric pressure A'in the chamber 8 reaches the point F before reaching the above-described lower limit value P1 at which generally no vacuum discharge occurs, the microwave irradiation into the chamber 8 by the magnetron 18 is performed. By continuing, the object to be thawed is heated.

After that, the controller 24 controls the chamber 8
After the internal pressure A ′ reaches the decompression equilibrium region B ′, the recompression process and the decompression process similar to the above are repeatedly executed with the microwave irradiation similar to the above. Then, as the temperature of the object to be thawed increases, the saturated vapor pressure in the chamber 8 rises, so that the decompression value in the decompression equilibrium regions B, B '... Gradually rises, and the decompression equilibrium regions B, B'. When it is determined that the depressurized value of ... Has reached a predetermined value, the atmosphere release valve 15 is opened and the thawing operation is ended.

As described above, in this structure, the object to be defrosted is thawed by irradiating with microwaves in a depressurized state (when the atmospheric pressure in the chamber 8 is less than the recompression upper limit value H).

Here, FIG. 1 shows the contents of the control corresponding to the discharge in the chamber 8 in the above-mentioned thawing operation. As described above, when the microwave irradiation is started by shifting from the first decompression process to the next decompression process, the inside of the chamber 8 is in a decompressed state, so that discharge easily occurs. Chamber 8
When a discharge occurs inside, the discharge light reaches the discharge sensor 23, and the discharge sensor 23 detects the discharge inside the chamber 8 and outputs a discharge detection signal.

The discharge generated in the above chamber 8 includes
Some are generated in the object to be thawed and some are generated in the chamber 8. Both of them are likely to occur at the stage when microwave irradiation is started. When the control device 24 determines from the output of the discharge sensor 23 that the discharge has occurred in the chamber 8, only the irradiation of the micro group is temporarily stopped (R
point).

After a predetermined time of several seconds (point S)
Then, the micro irradiation is restarted, and when it is judged from the output of the discharge sensor 23 that the discharge is generated in the chamber 8 again, only the micro irradiation is once again stopped (point R ′). ).

Further, after a predetermined time of several seconds (point S '), the micro irradiation is restarted, and at this restart, the discharge from the discharge sensor 23 further causes discharge in the chamber 8. If it is determined that, in this case, not only the irradiation of the micro group but also the re-pressurizing operation (opening of the pressure regulating valve 16) is stopped (point R ″), that is, the thawing operation is ended (the thawing operation thereafter is not performed. ).

When the thawing operation is finished in this way,
The control device 24 lights up the abnormality display lamp in the display lamp 6b of the display unit 6 and activates the buzzer 32, and further displays “Er” shown in FIG.
By displaying "r1", it is notified that the thawing operation has been completed. Therefore, the abnormality display lamp, the buzzer 32, and the display 6a function as a notification unit that notifies the outside of the aircraft that the thawing operation has been completed based on the detection of the discharge by the discharge sensor 23.

Regarding this notification, the buzzer 32 is activated again when the user opens the door 4 after the abnormality indicator lamp and the indicator 6a are activated as described above. As a result, the thawing operation has ended,
It is possible to more surely inform the user who thinks that the defrosting has been normally performed and is in the middle of the defrosting operation (the occurrence of an abnormality).

On the other hand, FIG. 2 also shows the content of the control corresponding to the discharge in the chamber 8 in the above-mentioned thawing operation.
When the control device 24 determines that a discharge has occurred in the chamber 8 at the time of transition from the pressure-regaining stroke to the next pressure-reducing stroke while irradiating the microwave, in this case, only the microwave radiation is stopped. (Point T), the depressurization operation continues.
Further, in this case, the following recompression process and decompression process are also executed, and in those processes, microwave irradiation is performed as described above.

As described above, according to this structure, the chamber 8 is
While alternately performing the process of depressurizing the interior and the process of decompressing the inside of the chamber 8, the control device 24 that irradiates the inside of the chamber 8 with microwaves to defrost the object to be defrosted, discharges electricity during the decompression process. When the sensor 23 detects a plurality of discharges, the thawing operation is terminated (FIG. 1).

As described above, according to the research results of the inventor, in the vacuum microwave defroster, there is a circumstance that electric discharge is likely to occur in the chamber 8 by being irradiated with microwaves in a depressurized state. Then, in a region where the degree of reduced pressure is large, discharge is likely to occur in both the object to be thawed and the chamber 8, and the amount of object to be thawed decreases as the degree of reduced pressure decreases. However, the discharge of the chamber 8 does not decrease even if the degree of pressure reduction decreases.

Therefore, as described above, when the discharge sensor 23 detects the discharge a plurality of times during the pressure recovery stroke, the discharge is generated although the degree of pressure reduction is gradually reduced. It is possible to determine that discharge has occurred in the chamber 8. In this situation, by ending the thawing operation, it is possible to eliminate discharge in the chamber 8 and prevent damage to the chamber 8.

In this case, the discharge of the chamber 8 is eliminated and the chamber 8 is not damaged even if the irradiation of microwaves is not completed but the entire thawing operation is completed. You can Therefore, the control device 24 may end the irradiation of at least the microwave when the discharge sensor 23 detects a plurality of discharges during the pressure recovery stroke. On the other hand, it is considered that discharge occurs in the object to be defrosted until the discharge sensor 23 detects the discharge a plurality of times during the pressure recovery process. In this situation, the discharge sensor detects the discharge thereafter. If there is not, the thawing operation can be completed by continuing the thawing operation accompanied by microwave irradiation.

Particularly, in the case of this configuration, the control device 24
During the pressure recovery process, when the discharge sensor 23 detects the discharge, only the microwave irradiation is temporarily stopped, the microwave irradiation is restarted thereafter, and the discharge sensor 23 detects the discharge thereafter. When this happens, the thawing operation is terminated.

As a result, the defrosting operation can be completed and the chamber 8 can be prevented from being damaged by finer control. In addition,
In this case, the number of discharge detections until the microwave irradiation is temporarily stopped and the number of discharge detections until the thawing operation is finished may be larger or smaller than those described above.

Further, the control device 24 stops only the microwave irradiation when the discharge is detected by the discharge sensor 23 during the depressurization process (FIG. 2). When discharge is detected by the discharge sensor 23 during this depressurization process, it can be determined that discharge has occurred in the object to be defrosted depending on the type of the object to be defrosted. It is more likely to occur. Therefore, in this situation, only the microwave irradiation is stopped to eliminate the discharge of the object to be thawed, and the operation can be continued to complete the thaw operation.

Further, when the control device 24 terminates the thawing operation based on the detection of the discharge by the discharge sensor 23, the notifying means for notifying the outside (the abnormality display lamp in the display lamp 6b and the buzzer 32). , And an indicator 6a). As a result, the end of the operation during the thawing operation,
It is easy for the user to understand.

In addition, the control device 24 controls the discharge sensor 2
It has a check function to confirm the operation of 3. As a result, the discharge generated in the chamber 8 can be detected after confirming the operation of the discharge sensor 23, so that the discharge can be detected more reliably. Further, the control device 24 confirms the operation of the discharge sensor 23 before starting the microwave irradiation in the thawing operation. As a result, the microwave is emitted after confirming the operation of the discharge sensor 23, so that the discharge can be detected more reliably.

Further, the control unit 14 confirms the operation of the discharge sensor 23 by the light of the inside lamp 14 that illuminates the inside of the chamber 8. As a result, the operation of the discharge sensor 23 can be confirmed by using the interior lamp 14 that illuminates the inside of the chamber 8, and a light source dedicated to confirm the operation of the discharge sensor 23 is not required.

In contrast to the above, FIG. 8 shows a different embodiment of the present invention. The same parts as those in the above-mentioned embodiment are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described. In this case, the control device 24 turns on the interior lamp 14 at the initial stage (point U) of the first decompression stroke, separately from when the door 4 is opened, and determines whether or not the discharge sensor 23 detects this light. Therefore, the operation of the discharge sensor 23 is confirmed (checked). Even in this case, since the microwave is emitted after confirming the operation of the discharge sensor 23, the discharge can be detected more reliably.

The controller 24 may confirm the operation of the discharge sensor 23 by the light outside the machine entering the chamber 8 when the door 4 is opened. In this case, since the operation of the discharge sensor 23 can be confirmed using the light outside the machine, a light source dedicated to confirm the operation of the discharge sensor 23 is not required as in the above. This is also suitable for implementation without the interior lamp 14. In addition, the present invention is not limited to the embodiments described above and shown in the drawings, and may be appropriately modified and implemented without departing from the scope of the invention.

[0053]

As described above, according to the vacuum microwave defroster of the present invention, it can be mainly determined that the discharge generated in the chamber is generated in the chamber, and the appropriate control can be performed. The effect of being able to do is obtained.

[Brief description of drawings]

FIG. 1 is a view corresponding to FIG. 6 showing control contents of an embodiment of the present invention.

FIG. 2 is a view corresponding to FIG. 6 showing different control contents.

[Fig. 3] Overall front view

FIG. 4 is a schematic vertical sectional side view of an internal configuration.

FIG. 5 is a block diagram of an electrical configuration.

FIG. 6 is an explanatory diagram of the entire thawing operation.

FIG. 7 is an enlarged front view of a display unit showing an example of notification.

FIG. 8 is an equivalent view of FIG. 6 showing a different embodiment of the present invention.

[Explanation of symbols]

6a is an indicator (notifying means), 6b is an indicator lamp (notifying means), 8 is a chamber, 14 is an interior lamp, 16 is a pressure regulating valve (recompressing means), 18 is a magnetron (microwave generator),
20 is a vacuum pump (pressure reducing means), 23 is a discharge sensor, 2
4 is a control device (control means), 32 is a buzzer (notification means)
Indicates.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hisano Kano             1-1, Shibaura, Minato-ku, Tokyo Toshiba Rye             Within Fu Engineering Co., Ltd. F term (reference) 3K086 AA05 BA08 CA09 CA12 CB20                       CC02 CC11 CD02 CD08 CD28

Claims (8)

[Claims] 1. A chamber for accommodating an object to be thawed, a decompression unit for decompressing the inside of the chamber, a decompression unit for decompressing the inside of the chamber, and a microwave generator for generating a microwave for irradiating the chamber. And a discharge sensor for detecting a discharge in the chamber, while performing a process of depressurizing the chamber and a process of decompressing the chamber alternately, while irradiating the chamber with microwaves. A control means for thawing the object to be thawed, wherein the control means terminates at least irradiation of microwaves when the discharge sensor detects a plurality of discharges during the recompression process. Vacuum microwave defroster, which is characterized by 2. The control means temporarily stops only the microwave irradiation when the discharge is detected by the discharge sensor during the pressure recovery stroke, restarts the microwave irradiation thereafter, and further discharges the discharge. The vacuum microwave defroster according to claim 1, wherein the defrosting operation is terminated when the discharge is detected by the sensor. 3. The vacuum microwave defroster according to claim 1, wherein the control means stops only the microwave irradiation when the discharge is detected by the discharge sensor during the depressurization process. 4. When the control means terminates the thawing operation based on the detection of the discharge by the discharge sensor, the control means has a notification means for notifying the outside of the aircraft.
The vacuum microwave defroster according to any one of 1 to 3. 5. The vacuum microwave defroster according to claim 1, wherein the control means has a check function for confirming the operation of the discharge sensor. 6. The vacuum microwave defroster according to claim 5, wherein the control means confirms the operation of the discharge sensor before starting the microwave irradiation in the defrosting operation. 7. The vacuum microwave defroster according to claim 5, wherein the control means confirms the operation of the discharge sensor by the light of an interior lamp that illuminates the inside of the chamber. 8. The vacuum microwave defroster according to claim 5, wherein the control means confirms the operation of the discharge sensor by using light outside the machine.