JP2905017B2 - High frequency heating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency heating apparatus for heating food or the like using high frequency.

[0002]

2. Description of the Related Art Conventionally, in a high-frequency heating apparatus, a browning plate for browning an object to be heated such as food using a high dielectric loss material such as ferrite has been widely proposed. Such a plate generates heat by absorbing high frequencies and converting it into heat. As a result, the object to be heated can be browned.

[0003] Such a browning plate is described, for example, in JP-A-1-204386. FIG. 24 is a sectional view showing an example in which such a browning plate is applied to a turntable of a high-frequency heating device. As shown in FIG. 24, a high-frequency absorption heating element 12 is laminated on a high-frequency transmission material 10. The browning plate described herein is formed on a dish, a table, a lid, or the like of food or the like, and is capable of browning not only the front surface but also the back surface of the food or the like.

However, there has been a problem that such a browning plate from the past cannot be used for thawing.

[0005] The conventional browning plate absorbs high frequencies and generates heat. Then, the part where the food placed thereon is in contact with the browning plate is thawed faster than the other parts. However, in general, the high-frequency absorptivity differs between the frozen portion and the melted portion by two digits or more. Therefore, the temperature of the once melted portion increases more and the temperature difference from the unmelted portion further increases. As a result, large uneven thawing occurred, so that the browning plate was not used during thawing.

Therefore, it is desirable to use a thawing plate using a material that does not generate heat at a high frequency during thawing.

FIG. 25 is a perspective view showing a conventional improved thawing plate 20. The thawing plate 20 is formed of polyethylene, polyurethane, or the like. As a result, since almost no high frequency is absorbed and there is no heat generation, even when used at the time of thawing, thawing of the object to be heated hardly occurs.

[0008] Fig. 25 shows a flat surface, but a device provided with a groove for releasing a drip (juice) from food is also used. FIG. 26 shows a perspective view of the thawing plate 22 provided with the grooves. FIG.
6 is a cross-sectional view of a portion along an arrow III-III of FIG.
It can be seen that the center of the thawing plate 22 is convex and the surface is grooved.

The above-mentioned polyethylene and polyurethane have higher thermal conductivity than air or food itself. Therefore, the thawing plate 20 not only does not generate heat but also diffuses heat in the horizontal direction, and has the function of reducing the temperature unevenness in the horizontal direction. FIG. 28 shows how the heat is diffused in the lateral direction.
As shown in FIG. 28, when the food 24 is placed on the thawing plate 20, the thawing plate 20 has a higher thermal conductivity than air or the like. Can be prevented.

Previously, in order to prevent uneven heat,
Although the thawing net 26 as shown in FIG. 29 was used, in this case, since the surroundings of the food 24 are air, thawing unevenness is more likely to occur as compared with the conventional improved example of FIG. Become. Also, the thawing net 26 was in the way during storage, but since the thawing plate 20 is a thin plate, there is no problem in the storage place.

FIG. 30 shows a state in which the thawing plate 20 is placed on the turntable 30 of the high-frequency heating device 28 and the food 24 is placed on the thawing plate 20 to perform thawing. The turntable 30 is placed on the weight sensor 32 and the motor 34. The high-frequency heating device 28 includes a magnetron 36 for generating high frequency, a waveguide 38 for guiding high frequency, the motor 34 and the magnetron 3.
6 is included.

Thus, if the material of the thawing plate 20 is made of polyethylene or the like, thawing unevenness can be reduced. Further, after the thawing is completed, the whole thawing plate 20 is taken out, and the thawing plate is used as a cutting board, and a kitchen knife or the like can be used.

[0013]

However, in the case of thawing using a thawing plate, the temperature of the portion where the food is in contact with the thawing plate (back side) rises faster than the front surface. When high-frequency radiation having the same intensity as that described above is applied, the temperature on the back surface increases sharply, causing temperature unevenness in the vertical direction.

The first reference example has been made in view of the above-mentioned problem, and an object thereof is to obtain a high-frequency heating device capable of preventing the back surface temperature from rising during thawing using a thawing plate. is there.

A first object of the present invention is to provide a high-frequency heating apparatus that automatically performs thawing according to the amount of an object to be heated, particularly thawing using a thawing plate.

A second object of the present invention is to obtain a defrosting plate which reduces defrosting unevenness by cooling the surface of the defrosting plate.

A third object of the present invention is to provide a high-frequency heating device capable of performing thawing control in consideration of ambient temperature and the like.

A fourth object of the present invention is to obtain a thawing plate which can be used both for thawing and for browning by changing the material of the front and back surfaces.

An object of the second embodiment is to obtain a high-frequency heating apparatus capable of performing more accurate thawing control by detecting the temperature of the object to be thawed during thawing.

[0020]

In order to solve the above-mentioned problems, a first reference example is a high-frequency heating apparatus for placing an object to be thawed on a thawing plate and irradiating a high frequency wave to defrost the object. A high-frequency heating device comprising: a high-frequency control unit that irradiates a strong high frequency in the first half of the thawing heating and irradiates a weak high-frequency in the second half of the thawing.

Therefore, in the latter half of the thawing, the internal heat generated by the high frequency is sufficiently conducted, and the generated temperature unevenness is reduced.

According to a first aspect of the present invention, there is provided a high-frequency heating device for thawing an object to be thawed by placing the object to be thawed on a thawing plate and irradiating a high frequency wave to thaw the object.
From the weight sensor for detecting the weight of the food, the thickness sensor for detecting the thickness of the food, the output signal of the weight sensor, and the output signal of the thickness sensor, the shape of the food, the food and the thawing An inference unit for inferring a contact area with the plate,
A high-frequency heating apparatus comprising: a control unit that controls a high-frequency irradiation pattern and an irradiation time based on a result of inference by the inference unit.

Therefore, it is possible to perform the optimal thawing according to the shape of the food.

According to a second aspect of the present invention, in order to solve the above-mentioned problems, an object to be thawed is placed on the object, and the object to be thawed is irradiated with high frequency to defrost the object to be thawed. A plate, receiving means for receiving a high frequency applied to the high-frequency heating device, and cooling means for cooling the surface of the thawing plate, using the received high frequency as a power supply,
It is characterized by having.

For this reason, by cooling the surface of the thawing plate, it is possible to reduce unevenness in thawing in the vertical direction when thawing the food.

According to a third aspect of the present invention, there is provided a high-frequency heating apparatus for thawing an object to be thawed by placing the object to be thawed on a thawing plate and irradiating the object with high frequency,
A weight sensor for detecting the weight of the food, an ambient temperature sensor for detecting the room temperature or the inside temperature, a temperature detecting means for detecting a surface temperature of the thawing plate, an output signal of the weight sensor, and an output signal of the ambient temperature sensor. A high-frequency heating apparatus comprising: a control unit that controls a high-frequency irradiation pattern and an irradiation time based on an output signal and a surface temperature of the thawing plate by the temperature detection unit.

Therefore, since the high-frequency irradiation time and the like are controlled based on the ambient temperature and the like, precise control of the thawing time is possible.

According to a fourth aspect of the present invention, there is provided a non-heating plate made of a material that does not absorb high frequency, a heating plate made of a material that absorbs high frequency and generates heat, and A thawing plate comprising a non-heating plate and a heat insulating layer sandwiched between the heating plate.

Therefore, if the non-heat-generating plate is used face up, it can be used for thawing, and if the heat-generating plate is used face up, it can be used for browning cooking.

A second reference example is a high-frequency heating apparatus having a function of thawing an object to be thawed in order to solve the above-mentioned problem, and a temperature detecting means for detecting a plurality of surface temperatures of the object to be heated. And a control unit for starting and stopping the high-frequency output. The control unit, when the initial temperature of the object to be thawed is all lower than a predetermined value (for example, 0 degrees Celsius), defrosts the plurality of points during thawing The high-frequency heating device is characterized in that the irradiation of the high-frequency is stopped when even at one point becomes a predetermined value (for example, 0 degree Celsius) or more.

Therefore, thawing can be performed while checking the temperature of the object to be thawed, so that more accurate thawing control can be performed.

[0032]

In the first reference example , since the high-frequency output in the second half is weakened, even if irregularity occurs in the first half, it can be eliminated in the second half.

In the first aspect of the present invention, the control unit performs thawing according to the thickness of the object to be heated and the like, so that optimal thawing control is automatically performed according to the size and weight of the object to be heated. Will be

The thawing plate according to the second aspect of the present invention is cooled by utilizing high frequency power, so that not only does it not generate heat, but also positively reduces the temperature unevenness of the object to be thawed.

The control section according to the third aspect of the present invention performs control in consideration of the ambient temperature and the like. Therefore, thawing can be appropriately performed under various environments, such as after continuously using the high-frequency heating device or after using the oven.

In the fourth aspect of the present invention, since the heat insulating layer is provided between the heat-generating plate and the non-heat-generating plate, they do not affect each other even when thawing and when browning. Can be used.

In the second reference example , thawing is performed while checking the temperature of the object to be thawed, so that excessive thawing can be prevented.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

The first reference example this reference example, a high-frequency heating device is varied in the first half and the second half and the intensity of high-frequency output at the time of thawing. In the early stage of thawing, the whole of the object to be thawed is frozen, so that high-frequency waves are hardly absorbed. Therefore, even if the high-frequency output is set to “strong”, temperature unevenness due to thawing hardly occurs. In the latter half, since it can be partially solved, the high-frequency output is set to "weak" and the temperature is made uniform by sufficient heat conduction. If the high-frequency heating is set to “weak” in the first half, the thawing takes too much time, the surface is melted too much, and the temperature unevenness in the vertical direction increases. In the present reference example, the high-frequency output is set to “strong” in the first half of decompression and “weak” in the second half, so that defrost unevenness can be reduced.

The manner of decompression according to this embodiment will be described with reference to the graph shown in FIG.

The horizontal axis of the graph in FIG. 1 is time, and the vertical axis is the intensity of the high-frequency output. As shown in FIG. 1, in this example, the high-frequency output is controlled only in two ways, ON and OFF, but by changing the ratio of the ON time and the OFF time, the average value of the high-frequency output is changed. Is possible.

FIG. 2 shows an example in which the high-frequency output is changed continuously. This is applied to a high-frequency heating device whose high-frequency output can be continuously changed by an inverter or the like.
Precise control can be performed compared to control. Further, in the example shown in FIG. 2, the period is not divided into two periods of the first half and the second half , but is divided into three periods. This allows for more precise control. Further, as shown by the broken line in FIG. 2, it is possible to obtain a better finished state by supplying a high-frequency output that is optimal for the defrosted state of the object to be defrosted.

Embodiment 1 In this embodiment, more accurate thawing control is performed by estimating the area where the object to be heated is in contact with the thawing plate from the weight and thickness of the object to be heated.

FIG. 3 is an explanatory view of the high-frequency heating device of the present embodiment. As shown in FIG. 3, the food 50 to be heated is placed on the turntable 54 via the thawing plate 52. Turntable 54
Are mounted on the weight sensor 56 and the motor 58. Inside the microwave oven 60, a light emitting unit 62 of an infrared thickness sensor for measuring the thickness of the food 50 and a light receiving unit 64 of the infrared thickness sensor are provided.

The weight sensor 56 measures the weight of the object to be thawed and outputs a signal representing the weight. The light emitting section 62 of the infrared sensor emits infrared light, and the light receiving section 64 receives the infrared light. If the infrared light is blocked by the object to be defrosted and the light cannot be received, it can be determined that the height (that is, the thickness) of the object to be defrosted reaches that portion. This determination is made in the control device 66 to which the light receiving signal output from the light receiving section 64 is supplied.

Based on signals from the weight sensor 56 and the infrared thickness sensors 62 and 64, the control device 66
Area where the food 50 is in contact with the thawing plate 52;
The shape of the food 50 is inferred. Then, the output of the magnetron 68 is adjusted in consideration of the area.

As shown in FIG.
Has a calculating means 70, and controls the high-frequency irradiation pattern and the heating time based on the weight signal and the thickness signal from the sensor group. FIG. 5 is a graph showing the time change of the high-frequency output in the present embodiment, in which the vertical axis represents the high-frequency output and the horizontal axis represents time. As shown in FIG. 5, this embodiment is similar to the first embodiment, except that
The average value of the high-frequency output is controlled by controlling the ratio of the / OFF time. That is, "strong time" in FIG.
The average value of the high-frequency output is in the "strong" state in the period indicated by, and the average value of the high-frequency output is in the "weak" state in the period thereafter. Needless to say, continuous control using an inverter or the like is also possible as a modification of the present embodiment.

As described above, in this embodiment, the infrared light sensors 62 and 64 are provided, and the control device 66 receives a signal from the light receiving portion 64, and determines whether or not the infrared light is received by the light receiving portion 64. Confirmed in the controller 66. If no light is received, the light emitting unit 62 and the light receiving unit 6
4, the food 50 is present, and it is determined that the thickness of the food 50 is at least a thickness from the surface position of the thawing plate 52 to the position where the infrared rays are blocked.

As described above, according to the present embodiment, the control device 66 is controlled based on the signals from the infrared thickness sensors 62 and 64.
Judge the thickness of the food 50. Therefore, the determined thickness and the food 5 measured by the weight sensor 56
From the weight of 0, the contact area of the food 50 with the thawing plate 52 is estimated. That is, it is assumed that the density of the food 50 is constant, and
Assuming that the contact surface shape is equal to 2, the following equation is generally established.

The weight of the food 50 = the contact area of the food 50 with the thawing plate 52 × the thickness of the food 50 Therefore, the contact area of the food 50 with the thawing plate 52 = the weight of the food 50 / the thickness of the food 50 , The contact area of the food 50 with the thawing plate 52 is calculated. Thus, the contact area and the food 50
Is known, it is possible to infer whether the food 50 is thin and wide or small, or thick and wide or small.

Therefore, for example, as shown in FIGS. 6A and 6B, when the food is thick, it is possible to make the thawing time longer and perform good thawing. FIG.
FIG. 6A shows the case where the thickness of the food 50 is small, and FIG.
(B) is when the food 50 is thick. FIG.
As shown in (b), when the food 50 is thick, the high frequency is absorbed near the surface of the food and hardly penetrates deep inside, so the high frequency heating time is set longer than when the food 50 is thin. You.

Although the infrared sensor is used to detect the thickness of the food 50 in the present embodiment, it is also preferable to detect the thickness of the food 50 using an ultrasonic sensor or the like. The ultrasonic sensor is usually provided with an ultrasonic transducer for transmitting and receiving ultrasonic waves, and after transmitting the ultrasonic waves, the transmitted ultrasonic waves are reflected on the target object, The time from returning to the ultrasonic transducer to receiving the wave is measured. By multiplying the measured time by the speed of sound, the distance from the ultrasonic transducer of the ultrasonic sensor to the target is calculated. By providing such an ultrasonic sensor on the ceiling of the microwave oven 60 and measuring the distance to the food 50, from the distance when the food 50 does not exist,
By reducing the measured distance, the thickness of the food 50 is measured.

Embodiment 2 In this embodiment, the thawing plate is provided with a cooling function to reduce temperature unevenness during thawing.

FIG. 7 is a sectional view of the thawing plate of this embodiment. As shown in FIG. 7, the thawing plate obtains a DC output by rectifying the high frequency power received by the antenna 80 by the power supply unit 84 having the diode 82. A lead 88 is drawn from a rectifier circuit board 86 provided with a diode 82, passes through a feedthrough capacitor 90, and is connected to a Peltier device 92. The high-frequency power is completely cut off by the feedthrough capacitor 90, thereby preventing a malfunction of a subsequent circuit.

The Peltier element 92 includes a metal heating plate 94.
And a front surface which is a metal cooling plate 96, and the same amount of heat absorbed by the cooling plate 96
4. When an electric current (DC) is applied to a material in contact with a dissimilar metal, a heat is generated (a heating plate 94),
On the other hand, it absorbs heat (cooling plate 96). Therefore, the food placed on the surface of the cooling plate 96 can be cooled.

What is characteristic in this embodiment is that the high-frequency power is received by the antenna 80 and the surface is cooled by using the high-frequency power. Thereby, it is possible to reduce the temperature unevenness at the time of thawing.

Further, in this embodiment, temperature detection using high frequency power is also performed. As shown in FIG. 7, in the present embodiment, a temperature detecting unit 98 configured by a thermistor or the like provided on the cooling plate 96 and a transmitting unit 100 that transmits the temperature detected by the temperature detecting unit 98 are provided. , An infrared LED 102 for transmitting a signal from the transmission unit 100 to the outside by infrared rays. The thawing plate according to the present embodiment uses the infrared LE
In order to transmit infrared rays from D102 to the outside and shield high frequencies, a transparent window provided with a metal mesh 104 is provided.

Since the infrared rays from the infrared LED 102 are emitted to the entire inside of the refrigerator, the reception can be performed regardless of whether the turntable on which the thawing plate is mounted is rotated, the food is placed, or the receiver is provided anywhere in the refrigerator. It is possible. As described above, the entire thawing plate is covered with metal except for the antenna 80 and the metal mesh 104, and shields the inside from high frequency so that there is no malfunction. The surface temperature of the thawing plate can be known by receiving the infrared light from the transparent window by the main body of the high-frequency heating device.

FIG. 8 is a plan view of the thawing plate of this embodiment.

FIG. 9 is a wiring diagram of the thawing plate of this embodiment. Reference numeral 103 denotes a storage battery connected to the output of the power supply unit, and 101 denotes a transistor for controlling the power supply to the Peltier element 92 to maintain the temperature of the cooling plate 96 at a constant value. The transmission unit 100 controls with a detection value of the temperature detection element 98 connected to the transmission unit 100. As described above, the high-frequency power received by the antenna 80 is converted to DC, and then supplied to the Peltier device 92 and the transmission unit 100. It can operate with the energy of the storage battery 103 even when no high frequency is radiated.

FIG. 10 is a plan view of the rectifier circuit board 86 of the power supply unit 84. Since the signal to be handled here has a high frequency, the components such as the diode 82 used need to be determined in shape in consideration of the distribution constant.

Further, in the above example, the structure of the thawing plate is complicated and therefore expensive, but as shown in FIG.
It is also preferable to adopt a structure wrapped in a. If the thawing plate having such a structure is cooled in advance in a freezer or the like, and then used in a high-frequency heating device, the object to be heated can be cooled.

Embodiment 3 This embodiment corrects that the temperature of the thawing plate changes depending on the surrounding environment and the thawing condition changes.

FIG. 12 is a configuration diagram of the high-frequency heating device of the present embodiment. The food and the like are stored in the thawing plate 110
And rotated by the turntable 112. The turntable 112 is mounted on a rotary plate 118 above the weight sensor 114 and the motor 116. The high-frequency heating device according to the present embodiment includes a receiving unit 120 for detecting a surface temperature of the high-frequency heating device based on an optical signal from the thawing plate 110, a wall temperature detecting element 122 for measuring a wall temperature, and detecting an ambient temperature. And a room temperature detecting element 124 for performing the operation.

When using the thawing plate shown in the above example, the initial temperature of the thawing plate affects the end of thawing. That is, if the initial temperature of the thawing plate is high, thawing is completed quickly, and if the initial temperature is low, it takes time. The temperature of the thaw plate is representative of room temperature. In the case of a microwave oven that uses a high-frequency heating device continuously or an oven that integrates an oven that uses an electric heater for heating, after the oven function is used, the temperature inside the refrigerator becomes high. Promotes thawing. Therefore, a good finish can be obtained by adjusting the thawing time depending on the temperature in the refrigerator. A temperature detection element 122 is provided in close contact with the outside of the refrigerator wall to detect the temperature inside the refrigerator as a representative.

Therefore, when using the thawing plate shown in the first reference example , the room temperature, the wall temperature and the weight of the food are calculated, and the time required for thawing (thawing time), the magnitude of the high frequency output and the Calculate the combination pattern of supply time.

When the thawing plate shown in the second embodiment is used, the surface temperature of the thawing plate is
Since the detection is made by 20, a calculation in which the initial temperature of the thawing plate is further added to the above calculation becomes possible, and the finish can be improved. It is also effective that control is performed by using the calculation result of the thawing time at this time as a predicted ending time of thawing, and that the final thawing end is detected from a change in surface temperature of the thawing plate.

The signals from the above four sensors and the like are supplied to the control device 126, and the control device 126 controls the power supply 130 of the magnetron 128 based on these values. Therefore, thawing control can be performed in consideration of conditions such as the ambient temperature, so that thawing with good finish can be performed.

FIG. 13 is a wiring diagram centered on the control device 126. The controller 126 includes a controller 132 that receives signals from four sensors and the like, and a magnetron power supply 130 that is controlled by the controller 132.
And a relay 134 for controlling the The controller 132 includes a calculating means 136 whose conceptual diagram is shown in FIG. As shown in FIG. 14, the calculating means 136 calculates a thawing time and a heating pattern from signals from four sensors and the like.

FIG. 15 is an example of a heating pattern. The example shown here is an example of a heating pattern in the case where the output of the magnetron 128 can be continuously varied.
At 1, the magnetron output is P1, during the next period t2, the magnetron output is P2, and during the last period t3, the magnetron output is P3.

In the above-described embodiment, the thawing plate is the same as the thawing plate of the second embodiment.
By using the function of the cooling plate 96 except for 2, it is possible to know the surface temperature of the thawing plate even during thawing. As a result, by detecting the inflection point of the temperature change during the thawing, it is possible to automatically know that the thawing is completed.

FIG. 16 is an explanatory diagram of this inflection point. That is, the high-frequency absorption rate changes depending on the state of freezing / thawing of the material to be thawed, and thus the temperature rise rate changes. In FIG. 16, this point is indicated by t0,
Before and after that, there are two states, a frozen state and a thawed state.

As described above, since the thawing can be performed while grasping the state of the thawing, more accurate thawing control can be performed.

In this example, the thawing plate of Example 2 was used as the thawing plate. By the way, since the power for surface cooling and for driving the thawing plate of the transmission unit 100 and the like is obtained from the high frequency, when the high frequency output is weak, that is, when the magnitude of the high frequency output is controlled to be small by an inverter or the like, it is often. It is also possible to stop the cooling that requires the electric power and to operate only the temperature detection of the thawing plate. When the maximum value of the high frequency power is intermittently obtained to obtain a small high frequency output as an average value,
It is also effective to perform cooling and temperature detection at a time when the maximum value of the high-frequency output is applied.

Further, in this embodiment, when the high-frequency output of the magnetron is weak, it is possible to periodically increase the high-frequency output for a short time and detect the temperature only at that moment. This is shown in FIG. As shown in FIG. 17, even when the high-frequency output is set to be weak, the high-frequency output is intermittently maximized, so that the temperature detection function of the thawing plate is activated to detect the temperature. The time for which the high-frequency output is the maximum output is selected to be sufficiently short so as not to affect the defrosting state.

As described above, according to the present embodiment, the ambient temperature, the surface temperature of the thawing plate, and the like can be detected, so that the thawing control matching them can be performed. FIG. 18 shows a state of thawing under various conditions. The case indicated by a in the figure is a case where the thawing plate is cooled in advance. In this case, the time until the decompression shown in the figure is completed is t2. The case indicated by b in the figure is the case where the thawing plate was at room temperature. In this case, the time to complete the decompression is t, as shown in the figure.
1 The case indicated by c in the figure is a case where another heating process is performed prior to thawing and the temperature in the refrigerator is high. In this case, as shown in the figure, the time until the decompression is completed is t3.

As described above, according to this embodiment, thawing control can be performed in consideration of various conditions. In addition, in order to detect the temperature of the thawing plate, it is also preferable to measure the temperature by an infrared temperature sensor. Further, by combining with the thickness sensor described in the first embodiment, more precise thawing control is possible.

Embodiment 4 In this embodiment, the front surface and the back surface are composed of a heat-generating surface and a non-heat-generating surface, respectively, and these are laminated with a heat insulator.

FIG. 19 is a perspective view of the thawing plate of this embodiment. FIG. 20 also shows an arrow X in FIG.
A cross-sectional view taken along line X-XX is shown. As shown in FIG. 20, a non-heat-generating surface 140 and a heat-generating surface 142 are stacked with a thermal insulator 144 interposed therebetween. Therefore, if the non-heat-generating surface 140 is used for the surface, it is suitable for thawing, and if the heat-generating surface 142 is used for the surface, it is suitable for browning dishes. In addition, as the thermal insulator, a foam of alumina or silica is preferable.

It is also preferable that the heat generating surface 142 be a groove or a wavy surface instead of a flat surface.
FIG. 21 is a cross-sectional view in the case of a wavy surface.
In the case of the wavy shape, the food 146 can be provided with a mesh-like brown.

As described above, the thawing plate of this embodiment is
Since the front and back sides have a heat-generating surface and a non-heat-generating surface, respectively, it can be used not only for thawing but also for cooked food.

The handle of the thawing plate is preferably formed of a material that does not generate heat from the viewpoint of handling.

SECOND REFERENCE EXAMPLE In this reference example, thawing control is accurately performed by measuring the initial temperature of food at a plurality of points.

[0084] According to the high frequency heating apparatus of the present embodiment, decompression is carried out in the following flow. (1) Place frozen food at the center of the turntable. (2) The weight of the food is detected by the weight sensor. (3) The initial temperature of the frozen food is measured by the infrared temperature sensor. This is performed in the following procedure. Although not shown, the infrared temperature sensor is configured to always detect the temperature of one point on the turntable. (3-1) Measure the temperature with an infrared temperature sensor. (3-2) Rotate the turntable 90 degrees. (3-3) The above (3-1) and (3-2) are repeated four times. (3-4) Calculate the average of the four temperatures. At this time, the average is calculated excluding the temperature close to the room temperature. If all four temperatures are equal to or higher than a predetermined value (for example, 0 degrees Celsius), no thawing is performed. The location (angle) at which the temperature was measured is stored in an internal storage unit, and the temperature at the same location is measured at regular intervals. The above measurement is shown in FIG. In FIG. 22, the frozen food as the object to be heated has a rectangular shape with a cutout. Then, each time the turntable is rotated 90 degrees, the temperature of the food is measured at each point between T1 and T4. In FIG. 22, since there is no food at the place where T2 is measured, the turntable surface, that is, the room temperature is measured. However, as described above, this is excluded and the average is calculated. That is, as shown in the lower part of FIG. 22, (T1 + T3
+ T4) / 3 is calculated.

(4) From the weight from the weight sensor and the above-obtained initial average temperature of the food, the strong high-frequency irradiation time and the estimated total thawing time are calculated. In the present reference example, the irradiated high frequency is the maximum output at first, but the weak high frequency is irradiated in the latter half.

(5) The estimated total thawing time is displayed. This display may be rough, for example, displayed every 30 seconds. Then, while the decompression is being performed, this display is counted down.

(6) Irradiation of high frequency with maximum output is performed for the above-mentioned high frequency irradiation time.

(7) The high-frequency output is weakened, and the temperature is measured every predetermined time or every rotation by the same method as in the above (3). At this time, it is necessary to measure the temperature at the same location. Then, if the temperature reaches 0 ° C. or more even in one place, it is determined that the thawing is completed, and the thawing is stopped. At this time, measurement is performed excluding the measurement points excluded in the above (3).

(8) As a result, if the total decompression time is longer than the expected total decompression time, a message such as "extend" is displayed, but if it is short, nothing is displayed.

As described above, decompression is performed. FIG. 23 shows a flowchart of the decompression process.

[0091] In this way, according to the present embodiment, since the thawing while checking the temperature of the food is carried out, fear is hardly too much to thaw.

[0092]

As described above, according to the first embodiment , a high-frequency heating apparatus with less thawing unevenness can be obtained.

According to the first aspect of the present invention, the weight of the object to be heated
A high-frequency heating device capable of performing appropriate thawing according to the thickness and the like is obtained.

According to the second aspect of the present invention, a thawing plate with less thawing unevenness can be obtained.

According to the third aspect of the present invention, there is provided a high-frequency heating apparatus capable of automatically performing appropriate thawing according to the ambient temperature and the like.

According to the fourth invention, there is provided a thaw plate which can be used both for thawing and for browning.

According to the second reference example , thawing is performed while checking the temperature of the object to be thawed, so that a high-frequency heating apparatus with a low risk of excessive thawing can be obtained.

[Brief description of the drawings]

FIG. 1 is a graph showing a state of thawing according to a first reference example .

FIG. 2 is a graph showing a state of decompression according to the first reference example , in a case where a high-frequency output is continuously varied.

FIG. 3 is an explanatory diagram of a high-frequency heating device according to the first embodiment.

FIG. 4 is a diagram illustrating an arithmetic unit 70 of the control device 66 according to the first embodiment.

FIG. 5 is a graph in a case where ON / OFF control is used for thawing according to the first embodiment.

FIG. 6 is a graph illustrating that thawing according to Example 1 is affected by the thickness of food.

FIG. 7 is a sectional view of a thawing plate according to a second embodiment.

FIG. 8 is a plan view of a thawing plate according to a second embodiment.

FIG. 9 is a wiring diagram of a thawing plate according to the second embodiment.

FIG. 10 is a plan view of a rectifier circuit board 86 according to the second embodiment.

FIG. 11 is a cross-sectional view in the case where the periphery of the cold storage material 104 is simply covered with the shield material 106 in the second embodiment.

FIG. 12 is a configuration diagram of a high-frequency heating device according to a third embodiment.

FIG. 13 is a wiring diagram centered on a control device 126 of the third embodiment.

FIG. 14 is a conceptual diagram of a calculation unit 136 according to the third embodiment.

FIG. 15 is a graph showing a heating pattern of Example 3 .

FIG. 16 is a graph illustrating an inflection point of a temperature change according to the third embodiment.

FIG. 17 is a graph showing how a magnetron periodically generates a maximum output in Example 3 .

FIG. 18 is a graph showing an example in which thawing is performed under various conditions by the high-frequency heating device according to the third embodiment.

FIG. 19 is a perspective view of the thawing plate of the fourth embodiment.

FIG. 20 is a sectional view of the thawing plate of the fourth embodiment.

FIG. 21 is a cross-sectional view when a heating surface 142 is a wavy surface in the fourth embodiment.

FIG. 22 is an explanatory diagram illustrating a state of measuring the temperature of food in the second reference example .

FIG. 23 is a flowchart of a decompression process in the second reference example .

FIG. 24 is a cross-sectional view when a conventional browning plate is used for a turntable of a high-frequency heating device.

FIG. 25 is a perspective view showing a conventional improved thawing plate.

FIG. 26 is a perspective view of a conventional improved thawing plate having grooves on its surface.

FIG. 27 is a cross-sectional view of the thawing plate of FIG. 26.

FIG. 28 is an explanatory view showing how heat of food placed on a conventional improved thawing plate is conducted.

FIG. 29 is an explanatory diagram showing how heat of food placed on a conventional thawing net is conducted.

FIG. 30 is an explanatory view showing a state in which thawing is performed by placing a conventional improved thawing plate on a turntable of a high-frequency heating device and placing food thereon.

[Explanation of symbols]

 Reference Signs List 50 Food 52 Thaw plate 54 Turntable 56 Weight sensor 58 Motor 60 Range store 62 Infrared thickness sensor light emitting part 64 Infrared thickness sensor light receiving part 66 Control device 68 Magnetron

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoyo Otsuka 2--14-40 Ofuna, Kamakura-shi, Kanagawa Prefecture, Living System Research Institute, Mitsubishi Electric Corporation (72) Inventor, Tsutomu Arai Omaeda, Hanazono-cho, Osato-gun, Saitama 1728 1 Mitsubishi Electric Home Equipment Co., Ltd. 1728 1 Mitsubishi Electric Home Equipment Co., Ltd. (72) Inventor Takahiro Kanai 1728 Koeda, Oaza-gun, Hanazono-cho, Osato-gun, Saitama Prefecture 1 56 Inside Mitsubishi Electric Home Equipment Co., Ltd. (56) References JP-A-3-95312 (JP, A JP-A-3-272591 (JP, A) JP-A-4-93520 (JP, A) JP-A-4-188594 (JP, A) ) Patent flat 5-39929 (JP, A) JitsuHiraku Akira 53-146147 (JP, U) JitsuHiraku Akira 55-123702 (JP, U) (58 ) investigated the field (Int.Cl. ^6, DB name) F24C 7/02 340 F24C 7/02 551

Claims (4)

(57) [Claims] 1. A high-frequency heating device for placing an object to be thawed on a defrosting plate and irradiating the object with high frequency to thaw the object to be thawed, comprising: a weight sensor for detecting the weight of the food; and a thickness sensor for detecting the thickness of the food. A thickness sensor, an output signal of the weight sensor, and an output signal of the thickness sensor, from an output signal of the thickness sensor, an inference unit that infers a shape of the food and a contact area between the food and the thawing plate, and the inference unit. Based on the inference result, a high-frequency output,
And a control unit for controlling the output time. 2. A thawing plate on which an object to be thawed is placed and used for irradiating the object to be thawed with a high frequency wave to defrost the object to be thawed, wherein the high frequency wave applied to a high frequency heating device Receiving means for receiving the high-frequency signal, rectifying means for rectifying the received high-frequency wave, and cooling means for supplying DC power rectified by the rectifying means, wherein the cooling means cools the object to be thawed. A thawing plate, characterized in that: 3. A high-frequency heating device for placing an object to be thawed on a thawing plate and irradiating a high frequency wave to defrost the object to be thawed, comprising: a weight sensor for detecting the weight of food; An ambient temperature sensor for detecting, a temperature detecting means for detecting a surface temperature of the thawing plate, an output signal of the weight sensor, an output signal of the ambient temperature sensor, and a surface temperature of the thawing plate by the temperature detecting means. A high-frequency heating device comprising: a control unit for controlling a high-frequency output and an output time based on the high-frequency output. 4. A non-heat generating plate formed of a material that does not absorb high frequency, a heat generating plate formed of a material that absorbs high frequency and generates heat, and is sandwiched between the non-heat generating plate and the heat generating plate. A thawing plate, comprising: a heat insulating layer;