JPH0898670A - Thawing system - Google Patents

Abstract

PURPOSE: To enable thawing of high quality with reduced unevenness in temperature distribution even in the thawed product having a high thawing completion temperature. CONSTITUTION: This thawing system has (1) a chilled air inlet 7 for introducing chilled air into a thawing chamber 3 formed with its inner walls at least appropriately apart from the rotation center of a turn table 5, (2) a means for deciding the point to start the rotation of the turn table 5 by recognizing the part which is readily heated and is to be used for the substrate to be thawed 4 by high-frequency waves from a high-frequency heater 15, (3) a starting point- detecting means 19 for detecting the time when the starting point comes in front of the chilled air inlet 7 by the rotating of the turn table 5, (4) a controlling means 17 for controlling at least one of the rotation of the turn table 5, the high-frequency heater 15 of chilling means 14, 16 by converting the detection output of the starting point detection means 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thawing device for thawing frozen foods and the like.

[0002]

2. Description of the Related Art Thawing of frozen products includes natural thawing, chilling in a refrigerator in a refrigerator, thawing using conduction heat or radiant heat in the thawing chamber, thawing using warm air, and thawing in a microwave oven. However, these thawing methods are very time-consuming and have large temperature unevenness (that is, uneven thawing), and it is difficult to obtain high-quality thawing. Especially in microwave ovens that use high-frequency heating, when the object to be thawed is thawed and the temperature near the surface melts to 0 ° C or higher, that portion is further heated due to the difference in the dielectric constant of ice and water that is characteristic of high-frequency heating. There is a characteristic that unevenness becomes large. Therefore, the microwave oven can be thawed in a short time, but if it is overheated, the temperature unevenness becomes large. On the other hand, high frequency is used to shorten the thawing time, and during the stoppage or thawing time of the high frequency generator, the cool air circulation fan is operated to blow cool air onto the surface of the object to be defrosted, There is a method in which the unevenness of the surface and the center is prevented by suppressing the rise in the temperature and the thawing quality is improved (JP-A-61-23567). However, this thawing method is very effective for food such as sashimi that is heated to an ice temperature zone around 0 ° C, but when thawing to a temperature higher than this, the melting point peculiar to high frequency heating described above is It is heated and the temperature unevenness increases. Therefore, thawing using cold air and high-frequency heating is still insufficient because high-quality thawing cannot be performed depending on the object to be thawed such as meat having a high end temperature. In particular, frozen shortcakes, sushi, and the like, which have the characteristic that the shape and material of food are not uniform and easily heat locally, tended to have a large temperature difference.

[0003]

As described above, the thawing method using high-frequency irradiation and cold air circulation heats the object to be thawed while cooling it as compared with ordinary high-frequency heating, so that the temperature difference between the vicinity of the center and the surface is small. Good thawing can be expected. However, in order to perform high-quality defrosting of foods with a high defrosting end temperature of 0 ° C or higher, the temperature rises from the melting point due to the difference in ease of heating peculiar to high-frequency heating, resulting in large temperature unevenness. There was a problem that became.

Therefore, the present invention provides a defrosting apparatus capable of performing high-quality defrosting with little temperature unevenness even on an object to be defrosted having a high defrosting end temperature by strongly cooling the food by warming it with cooling air. The purpose is to provide.

[0005]

In order to solve the above-mentioned problems, the invention according to claim 1 irradiates a high-frequency wave into the thawing chamber to heat an object to be defrosted, and a high-frequency heating means for causing the thawing chamber to flow into the thawing chamber. Cooling means for generating cold air, a turntable on which the object to be defrosted is placed and rotated, and the cold air formed in the thaw chamber inner wall including at least an appropriately separated position from a position above the center of rotation of the turntable to store the cold air in the thaw chamber. A cold air flow inlet for inflowing, a starting point determining means for deciding a starting point of rotation of the turntable by recognizing a heated portion of the object to be thawed by the high frequency, and the starting point of the cold air flow inlet for rotation of the turntable. Starting point detecting means for detecting when it is located in front of, and rotation of the turntable upon receiving the detection output of the starting point detecting means, the high frequency heating means or the And summarized in that a control means for controlling at least one of retirement unit.

According to a second aspect of the invention, in the thawing apparatus according to the first aspect, the starting point determining means is a portion where the user grasps the heating characteristics of the object to be defrosted and is easily heated. It is a mark written on the turntable in order to place the mark facing, and the notation position of the mark is the starting point.

According to a third aspect of the invention, in the defrosting apparatus according to the first aspect, the starting point determining means recognizes the shape of the object to be defrosted, and the object to be defrosted is heated based on the recognition result. It is a shape recognition means for discriminating an easy portion, and the gist is that the portion discriminated as being easily heated is the starting point.

According to a fourth aspect of the invention, in the thawing apparatus according to the first aspect, the starting point determining means two-dimensionally detects the temperature of the object to be thawed, and relatively based on the detection result. The gist of the present invention is a temperature detecting means for discriminating a portion having a high temperature, and a portion where the object to be thawed is discriminated to have a high temperature is the starting point.

According to a fifth aspect of the invention, in the thawing apparatus according to the first aspect, the control means receives the detection output of the starting point detecting means and increases the amount of cold air flowing into the thawing chamber. The gist is to control the cooling means.

According to a sixth aspect of the present invention, in the thawing apparatus according to the first aspect, the control means receives the detection output of the starting point detecting means and reduces the rotation speed of the turntable so that the starting point is The gist is to control so as to rotate at a normal speed again after substantially passing through the cold airflow inlet.

The invention according to claim 7 is the thawing apparatus according to claim 6, wherein the control means controls the heating power of the high-frequency heating means in proportion to the rotation speed of the turntable. To do.

According to an eighth aspect of the present invention, in the defrosting apparatus according to the first aspect, the control means receives the detection output of the starting point detection means, stops the rotation of the turntable, and the high frequency heating means. The heating method is stopped, and the high frequency heating means controls the heating when the turntable is rotated.

A ninth aspect of the present invention is characterized in that, in the thaw apparatus according to the eighth aspect, the control means controls so as to lengthen the stop time of the turntable with the passage of time.

[0014]

According to the first aspect of the invention, at the starting point of rotation of the turntable, a portion where the object to be thawed is easily heated by high frequency, such as a pointed portion, is located. With the rotation of the turntable, when this starting point is located in front of the cold airflow inlet, it is detected by the starting point detection means, and upon receipt of this detection output, rotation of the turntable, high-frequency heating means, or at least one of cooling means. Is controlled to suppress the temperature rise of the portion of the thawed material that is easily heated. As a result, partial over-thawing is suppressed, and it becomes possible to perform high-quality thawing with little temperature unevenness even for an object to be thawed having a high thawing end temperature.

According to the second aspect of the invention, when the user performs thawing on the object to be thawed whose heating characteristics are known in advance, a mark such as an arrow indicating a direction is provided on the turntable. Is the starting point determining means. The user
By placing the object to be thawed on the turntable with its easily heated portion facing the mark, the notation position of the mark functions as a starting point.

According to the third aspect of the present invention, the shape recognizing means for recognizing the shape of the thawed object as the starting point determining means and discriminating the easily heated portion of the thawed object based on the recognition result is used. The position of the starting point is automatically determined by simply placing an object to be thawed on the turntable.
This makes it easy to operate.

In the invention according to claim 4, as the starting point determining means, the temperature detecting means is used which two-dimensionally detects the temperature of the object to be thawed and determines the portion having a relatively high temperature based on the detection result. As a result, the portion where it is determined that the object to be thawed is at a high temperature is automatically determined as the starting point, so that the simplicity of the operation can be obtained as described above.

In the invention according to claim 5, by increasing the amount of cold air flowing into the thawing chamber in response to the detection output of the starting point detecting means, the temperature rise of the easily heated portion of the thawing object is effectively suppressed. Therefore, it is possible to reduce heating unevenness with other portions.

In the invention according to claim 6, the rotation speed of the turntable is reduced in response to the detection output of the starting point detection means, so that the portion of the thawed material that is easily heated is cooled well and the other portion is heated. It is possible to reduce unevenness.

In the seventh aspect of the invention, when the rotation speed of the turntable is reduced in response to the detection output of the starting point detection means, the heating power of the high frequency heating means is reduced in proportion to this, whereby the defrosting target is defrosted. It is possible to further cool the portion of the article that is easily heated, and further reduce uneven heating with other portions.

In the eighth aspect of the present invention, the object to be thawed is heated by stopping the rotation of the turntable in response to the detection output of the starting point detecting means and stopping the heating by the high frequency heating means in synchronization with this. The easy portion is further cooled, and it becomes possible to further reduce uneven heating due to other portions.

In the ninth aspect of the invention, when the rotation of the turntable and the heating by the high frequency heating means are stopped in response to the detection output of the starting point detection means as described above, the stop time is lengthened with the passage of time. By doing so, the temperature of the object to be thawed is much lower than the ice temperature zone in the initial stage of thawing, and heating unevenness does not occur, so the temperature rise during this period can be accelerated and the thawing time can be shortened. .

[0023]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 10 are views showing a first embodiment of the present invention. As shown in FIG. 1, a thawing device 1 is provided with a door 2 having a mechanism for preventing high-frequency leakage, a thawing chamber 3 made of metal around the thawing unit 4, and a thawing object 4 for rotating. A turntable 5, a waveguide opening 6 for feeding high frequency waves into the thawing chamber 3, a cold airflow inlet 7 and a cold airflow outlet 8 for circulating cold air in the thawing chamber 3 are provided, and a display unit is provided outside the thawing chamber 3. 9, an operation unit 10, and a mode selection unit 11 for inputting conditions necessary for defrosting. The cold airflow inlet 7 and the cold air outlet 8 are radio wave shielding vents that block high frequencies, and the vents are made of punching metal, for example. Further, as shown in FIG. 2, the thawing chamber 3 and the cold air circulation passage 22 are covered with the heat insulating material 12, and the cold air circulation fan 13 is rotated to remove the air cooled by the cooler 14.
It is supposed to be sent to. The cooler 14 is a compressor 16
It is cooled by compression and expansion of the refrigerant. The cooler 14 and the compressor 16 constitute a cooling means. A high frequency generator 15 as a high frequency heating means is connected to the waveguide opening 6 by a waveguide not shown. The operation, stop and output of the high frequency generator 15 are controlled by a control circuit 17 as a control means. Turntable 5
The object to be defrosted 4 is rotated by the turntable motor 23 when heating is started. By controlling the rotational speed of the cold air circulation fan 13 provided on the cold air circulation passage 22 side of the cold air flow inlet 7, it is possible to change the amount of cold air coming out of the cold air flow inlet 7.

Next, the operation of the decompression device 1 having the above configuration will be described. First, the defroster 1 operates the compressor 16 in advance to cool the air with the cooler 14, and the cool air circulation fan 13
Is rotated and the thaw chamber 3 is sufficiently cooled to, for example, 0 ° C. The door 2 is opened, the object to be defrosted 4 is placed on the turntable 5, the door 2 is closed, conditions necessary for defrosting the object to be defrosted 4 are input from the mode selection means 11, and the operation section 10 is operated to defrost the object. Is started. At this time, the input content and the operation status are displayed on the display unit 9. As the thawing operation is started, the turntable motor 23 is energized to defrost the object 4
Is rotated and a high frequency is supplied from the high frequency generator 15 to the thawing chamber 3 to heat the object to be defrosted 4. The heating pattern is calculated in advance in the control means 17 according to the input information, and the heating pattern is performed in a manner suitable for the type and amount of the object to be thawed 4. At this time, at the same time, the control means 17 controls the compressor 16 and the cold air circulation fan 13
Is continuously operated or intermittently operated to blow cold air of, for example, −10 ° C. into the defrosting chamber 3 from the cold airflow inlet 7, and thaw by high-frequency heating while applying cold air to the object to be defrosted 4.

FIG. 3 is a block diagram showing the control system of the control means 17. Basically, the control means 17 controls the operation of the cooling means including the high-frequency heating means 15, the cooler 14, the compressor 16 and the cool air circulation fan 13 at the start of thawing, and the position serving as the starting point of the rotation of the turntable 5. Is determined by the starting point determining means 18, and the starting point detecting means 19 detects that the starting point approaches the cold airflow inlet 7, and controls the rotation of the turntable 5.

FIG. 4 shows a first example of the starting point determining means 18. An arrow 18a indicating a direction is attached on the turntable 5. When the user defrosts the food (thawed material 4) whose heating characteristics are known in advance, the portion that is likely to become warm is placed on the turntable 5 in the direction of arrow 18a. FIG. 5 shows a first example of the starting point detecting means. A reflecting plate 5a is attached to the outer periphery of the turntable 5 at the tip of the arrow 18a shown in FIG. 4, and a light emitting element 19a is provided below the cold airflow inlet 7. The light receiving element 19b is attached. With the rotation of the turntable 5, an output signal as shown in FIG. 6 is obtained. In response to this signal, the control means 17 controls the rotation of the turntable 5, the high frequency heating means 15 and the cooling means (cooler 14, compressor 16, cold air circulation fan 13 and the like), and the starting point is the object to be defrosted 4 It controls the temperature rise by exposing it to cooler air than other parts.

Next, the first control method will be described. For example, the cool air circulation fan 13 of the cooling means is configured to be capable of changing the rotation speed, and the rotation speed is increased for a predetermined time period in synchronization with the output signal of the starting point detection means 19 to increase the air volume. . FIG. 7 is a graph showing an operation pattern of each part of the turntable 5, the cool air circulation fan 13, the high frequency heating means 15 and the like at this time, and is directed in the direction of an arrow 18a which is a starting point accompanying the rotation of the turntable 5. The pointed portion of, for example, the shortcake of the placed object to be thawed 4 is cooled by receiving more cooling air than other portions. As a result, the temperature rise in the pointed portion that is easily heated by microwaves is suppressed, and it becomes possible to reduce uneven heating with other portions.

Next, the second control method will be described. The motor 23 of the turntable 5 is configured to have a variable speed, and is synchronized with the output signal of the starting point detection means 19 to reduce the rotation speed for a predetermined time and rotate slowly. FIG. 8 shows the motor 23 and the cold air circulation fan 13 at this time.
3 is a graph showing an operation pattern of each part of the high frequency heating means 15 and the like. When the output signal of the starting point detection means 19 is received along with the rotation of the turntable 5, the control means 17 controls the rotation speed of the motor 23 of the turntable 5. At the same time, the heating power of the high frequency heating means 15 is also reduced at substantially the same rate. After a lapse of a predetermined time, the original state is restored and this is repeated. As a result, the portion of the frozen food 4 hitting in the direction of the starting arrow 18a is cooled well, and the heating power of the high-frequency heating means 15 is also reduced according to the rotation speed, so the power per rotation is also averaged. Cage,
It is possible to reduce uneven heating with other parts.

As described above, the first and second control methods are
Although it is effective to carry out each independently, if the cooling air flow rate is increased while the rotation speed is decreased, the cooling effect is further improved and uneven heating can be reduced.
The control methods may be performed simultaneously.

The third control method will be described. This control method is a push-up of the second control method described above, and when the arrow 18a, which is the starting point of rotation in synchronization with the output signal of the starting point detection means 19, comes to the front of the cold airflow inlet 7, the turntable. The rotation of No. 5 is stopped, and at the same time, the high frequency heating device 1
5 is also stopped and maintained in a state of locally cooling for a predetermined time. When the rotation is started, heating is started again and this is repeated. FIG. 9 is a graph showing the operation pattern of each part at this time. In this way, the control means 17 causes the high-frequency heating means 15 and the motor 23 of the turntable 5 to operate intermittently in synchronization with the rotation cycle of the turntable 5. As a result, the part to be thawed 4 is easily cooled while it is stopped, and uneven heating can be suppressed. In addition to this, FIG. 9 shows the case where the stop time is always constant, but if the control as shown in FIG. 10 is performed in which the stop time is lengthened as needed according to the progress of the defrosting, the defrosting will be more effective. Can be realized. At the initial stage of thawing, the temperature of the object to be thawed 4 is still much lower than the ice temperature zone, so that there is not much heating unevenness. Therefore, heating is continuously performed until a part of the object to be thawed 4 rises to near 0 ° C. to shorten the thawing time. After that, the intermittent operation is started, the stop time is gradually extended, and the cooling is controlled sufficiently to prevent overheating.

FIG. 11 shows a second embodiment of the present invention.
In this embodiment, the configurations of the starting point determining means and the starting point detecting means are different from those of the first embodiment. In FIG. 11, reference numeral 20 denotes a shape recognition means, which is an ultrasonic sensor 20a,
20b and its control circuit 20c. The ultrasonic sensor 20b is attached just above the cold airflow inlet 7. The thawing is started by operating the mode selecting means 11 and the operating section 10, and first, only the turntable 5 is rotated to determine the distance to the object to be defrosted 4 placed on the turntable 5 by the shape recognizing means 20 by the ultrasonic sensor 20a. , 20b, the outer shape of the object to be thawed 4 is grasped, and the control circuit 20c discriminates a portion having a shape that changes abruptly to determine the position as the starting point of the rotation of the turntable 5 and the ultrasonic sensor 20.
At b, it is detected that the signal at the starting point is closest, and a signal as shown in FIG. 6 is output to the control means 17. After this,
The control means 17 operates the high frequency heating means 15 to start heating and perform thawing. This allows the user to arbitrarily place the object to be thawed 4 on the turntable 5 and automatically control it, which simplifies the operation.

FIG. 12 shows a third embodiment of the present invention.
This embodiment is similar to the first embodiment except that the configurations of the starting point determining means and the starting point detecting means are changed. In FIG. 12, reference numeral 21 is a temperature detecting means, which is composed of an infrared temperature detecting sensor 21a capable of two-dimensionally detecting the temperature and a control circuit 21b thereof. The infrared temperature detection sensor 21a is mounted immediately above the cold airflow inlet 7.
The mode selection unit 11 and the operation unit 10 are operated to start thawing, the turntable 5 is rotated, and at the same time, the high frequency heating unit 15 is operated to start heating. The portion where the temperature rises to the ice temperature zone after heating for a while is measured by the infrared temperature detection sensor 21a, and the portion is determined as the starting point of rotation. Further, it is detected that this position is closest to the cold airflow inlet 7, and a signal as shown in FIG. 6, for example, is output to the control means 17 in the same manner as above.

In the case of the starting point determining means 18 shown in FIG. 4, the starting point detecting means 19 uses an optical element as an example thereof in FIG. 5, but in addition, a part of the rotating portion such as the turntable 5 is used. It is also possible to provide a protrusion on the switch so that the switch is turned on / off by the movement of the protrusion so that the switch outputs a signal as shown in FIG.

Further, although the present invention relates to the thawing apparatus, it does not matter if the thawing chamber 3 is incorporated in the refrigerator. FIG. 13 shows a configuration example in which the defroster is incorporated in the refrigerator 24. The high-frequency heating device 15 is installed outside the heat insulating material on the upper back side, and the cooler 14 and the compressor 16 of the refrigerator 24 are shared. This is because the structure can be easily realized.

[0035]

As described above, according to the first aspect of the invention, the high-frequency heating means for irradiating the thaw chamber with the high frequency to heat the object to be thawed, and the cooling for generating the cold air flowing into the thaw chamber. Means, a turntable on which the object to be thawed is rotated, and a cold air flow which is formed on the thaw chamber inner wall including at least an appropriately separated position from a position above the center of rotation of the turntable and allows the cool air to flow into the thaw chamber. An inlet, starting point determining means for recognizing a heated portion of the object to be thawed by the high frequency to determine a starting point of rotation of the turntable, and the starting point positioned by the rotation of the turntable in front of the cold airflow inlet. The starting point detecting means for detecting the time of rotation, and the rotation of the turntable in response to the detection output of the starting point detecting means, the high frequency heating means or the cooling means Since a control means for controlling either of them is provided, it is possible to suppress a temperature rise of a portion of the object to be thawed that is easily heated, partial overthawing is suppressed, and an object to be thawed having a high defrosting end temperature is provided. However, high-quality thawing with less temperature unevenness can be performed.

According to the inventions described in claims 2 to 9, in addition to the effects of the invention described in claim 1, the following effects are further provided.

According to the second aspect of the present invention, the starting point determining means allows the user to grasp the heating characteristics of the object to be thawed and place the turnable part of the object to be thawed so as to face it. Since the mark is written on the table, and the position where the mark is written is the starting point, the starting point can be easily determined when the user knows the heating characteristics of the thawed material in advance. it can.

According to the third aspect of the present invention, the starting point determining means recognizes the shape of the object to be thawed and, based on the recognition result, the shape recognizing means for judging the easily heated portion of the object to be thawed. The position of the starting point is automatically determined by simply placing the defrosting object on the turntable by the user, since the starting point is the portion that is determined to be easily heated. The convenience of operation can be improved.

According to the fourth aspect of the present invention, the starting point determining means two-dimensionally detects the temperature of the object to be defrosted, and based on the detection result, the temperature at which a relatively high temperature is determined. Since the detection means is the portion where the object to be thawed is determined to be high temperature is set as the starting point, the starting point can be accurately determined and the convenience of the operation can be improved.

According to the fifth aspect of the invention, the control means receives the detection output of the starting point detection means and controls the cooling means so as to increase the amount of cold air flowing into the defrosting chamber. Therefore, it is possible to effectively suppress the temperature rise of the portion of the object to be thawed that is easily heated.

According to the sixth aspect of the present invention, the control means receives the detection output of the starting point detecting means, reduces the rotation speed of the turntable, and the starting point passes substantially through the cold airflow inlet. Since the control is performed so as to rotate at the normal speed again, it is possible to effectively cool the easily heated portion of the thawed material.

According to the invention of claim 7, the control means controls the heating power of the high-frequency heating means in proportion to the rotation speed of the turntable, so that the portion to be thawed is easily heated. Can be cooled more effectively.

According to the eighth aspect of the present invention, the control means receives the detection output of the starting point detection means and stops the rotation of the turntable and the heating by the high frequency heating means to stop the turn. Since the control is performed so that the table is rotated by the high-frequency heating means, it is possible to more effectively suppress the temperature rise of the easily heated portion of the thawed material.

According to the ninth aspect of the present invention, the control means controls so as to lengthen the stop time of the turntable with the lapse of time. Since the temperature is much lower than the ice temperate zone and no uneven heating occurs, the temperature rise at this time can be accelerated and the thawing time can be shortened.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which a door is opened in a first embodiment of a thawing device according to the present invention.

FIG. 2 is a sectional view showing an internal structure of the first embodiment.

FIG. 3 is a block diagram showing a control system of the first embodiment.

FIG. 4 is a diagram showing a first example of a starting point determining means in the first embodiment.

FIG. 5 is a configuration diagram showing a first example of a starting point detecting means in the first embodiment.

FIG. 6 is a waveform diagram showing an output signal of the starting point detecting means.

FIG. 7 is a timing chart for explaining a first control method in the first embodiment.

FIG. 8 is a timing chart for explaining a second control method in the first embodiment.

FIG. 9 is a timing chart for explaining a third control method in the first embodiment.

FIG. 10 is a timing chart for explaining a fourth control method in the first embodiment.

FIG. 11 is a sectional view showing the internal structure of the second embodiment of the present invention.

FIG. 12 is a sectional view showing the internal structure of the third embodiment of the present invention.

FIG. 13 is a schematic cross-sectional view showing a structural example in which the embodiment of the present invention is incorporated in a refrigerator.

[Explanation of symbols]

 3 Thaw chamber 4 Thawed material 5 Turntable 6 Waveguide opening 7 Cold airflow inlet 8 Cold airflow outlet 13 Cool air circulation fan 14 Cooler 15 High frequency generator (high frequency heating means) 16 Compression that constitutes cooling means together with cooler Device 17 Control means 18 Starting point determining means 18a Arrow 19 Starting point detecting means 19a Light emitting element 19b Light receiving element 20 Shape recognizing means 20a, 20b Ultrasonic sensor 21 Temperature detecting means 21a Infrared temperature detecting sensor

Claims (9)

[Claims] 1. A high-frequency heating means for radiating a high frequency to the thaw chamber to heat the object to be thawed, a cooling means for producing cold air to flow into the thaw chamber, and a turntable on which the object to be thawed is rotated. A cold airflow inlet formed in the thawing chamber inner wall including a position at least appropriately separated from the position above the center of rotation of the turntable to allow the cold air to flow into the thawing chamber, and a portion where the object to be thawed is easily heated by the high frequency. Starting point determining means for recognizing and determining the starting point of rotation of the turntable, starting point detecting means for detecting when the starting point is located in front of the cold airflow inlet by rotation of the turntable, and detection of the starting point detecting means Control means for receiving the output and controlling at least one of the rotation of the turntable, the high frequency heating means and the cooling means. Defrosting device. 2. The starting point determining means is a mark written on the turntable so that the user can grasp the heating characteristics of the object to be thawed and place the easily heated portion of the object to be thawed. The decompressing device according to claim 1, wherein the notation position of the mark is the starting point. 3. The starting point determining means is a shape recognizing means for recognizing the shape of the object to be thawed and discriminating a portion of the object to be thawed which is likely to be heated based on the recognition result. The defrosting device according to claim 1, wherein a portion determined to be easily heated is the starting point. 4. The starting point determining means is a temperature detecting means that two-dimensionally detects the temperature of the object to be defrosted, and determines a portion having a relatively high temperature based on the detection result. The defrosting device according to claim 1, wherein a portion where the object is determined to be high temperature is the starting point. 5. The control means receives the detection output of the starting point detection means and controls the cooling means so as to increase the amount of cold air flowing into the defrosting chamber. Defroster. 6. The control means receives the detection output of the starting point detecting means, reduces the rotation speed of the turntable, and causes the starting point to rotate again at a normal speed after substantially passing through the cold airflow inlet. The thawing device according to claim 1, wherein the thawing device is controlled. 7. The thawing device according to claim 6, wherein the control means controls the heating power of the high-frequency heating means in proportion to the rotation speed of the turntable. 8. The control means receives the detection output of the starting point detection means, stops rotation of the turntable, and stops heating by the high frequency heating means,
The thawing device according to claim 1, wherein the high-frequency heating means is controlled to heat the turntable when it is rotated. 9. The defrosting apparatus according to claim 8, wherein the control means controls the stop time of the turntable to increase with a lapse of time.