KR100215036B1 - Thawing method and apparatus for microwave oven - Google Patents

Abstract

The present invention relates to a defrosting apparatus for a microwave oven and a method thereof. The present invention relates to a temperature sensing means (32) for sensing a temperature of food (2) placed on a turntable (4) and an output of the temperature sensing means (32). It comprises a turn table motor 28, the magnetron 30, the microcomputer 34 for controlling the fan motor 31, while measuring the weight of the marine animal 22 in accordance with the rate of temperature change of the marine animal 22 Step S10; Setting a first thaw target temperature T1 and a second thaw target temperature T2 according to the weight of the sea animal 22 (S20); Driving the magnetron 30 at a first duty ratio to thaw the sea animal 22 to a first thawing target temperature T1 (S30); Driving the magnetron 30 at a second duty ratio to thaw the sea animal 22 to a second thawing target temperature T2 (S40); By driving the magnetron 30 at a third duty ratio for a predetermined time and then thawing and ending in step S50, the animal can be optimally thawed regardless of the initial temperature of the animal.

Description

Microwave defrosting device and its defrosting method

1 is a schematic view of a conventional microwave oven,

2 is a schematic view of a microwave oven according to the present invention,

3 is a circuit diagram of a temperature sensing means according to the invention,

4 is a flowchart of a method for thawing a microwave oven according to the present invention;

5 is a graph showing the correlation between the weight of the sea animal and the rate of change of the sea animal,

6 is a graph for explaining a magnetron driving method according to a temperature change of a sea animal.

Explanation of symbols for main parts of the drawings

22: sea animals 24: turn table

26: cooking chamber 28: turntable motor

30: magnetron 32: temperature sensing means

32-1: infrared sensor 32-2: amplifier

32-3: Band pass filter unit 34: Micom

The present invention relates to a thawing apparatus for a microwave oven and a thawing method thereof, and in particular, a thawing apparatus for a microwave oven that performs thawing by setting a thawing temperature suitable for each weight after determining the weight of the sea animal using an initial temperature rise rate of the sea animal. It is about a thawing method.

Recently, frozen foods for extending the shelf life have increased, and microwave ovens equipped with a function of thawing such frozen foods have been widely used.

The conventional microwave oven equipped with the above-described thawing function includes a cooking chamber 6 equipped with a turn table 4 for placing food and food 2 as shown in FIG. 1 and the turn table 4. A turn table motor 8 for rotating the light source, a magnetron 10 for supplying a high frequency into the cooking chamber 6, and a weight sensor 12 for sensing the weight of the food 2 placed on the turn table 4. And a microcomputer 14 for controlling the turn table motor 8 and the magnetron 10 according to the output of the weight sensor 12.

In the microwave oven configured as described above, when a thaw command is input from the outside, the microcomputer 14 operates the turn table motor 8 without driving the magnetron 10 to operate the turn table 4 at a speed of 6 rpm. Rotate to

At this time, the weight sensor 12 calculates the average weight of the sea animal 2 by sensing the average of the load of the turntable 4 for 1 minute.

Then, the thawing time is set in proportion to the detected weight. That is, the thawing time is determined by multiplying the detected weight by a constant constant (k).

Then, the set thawing time is divided into a predetermined ratio (for example, 40:30:30) to drive the magnetron at different periods according to each ratio.

However, since the thawing time of the conventional microwave oven detects the weight of the sea animal and sets the thawing time to be proportional to the weight, the portion of the initial temperature of the sea animal is not considered.

Therefore, when the initial temperature of the sea animal is high, the sea animal is over-thawed, and when the initial temperature of the sea animal is low, there is a problem of unthawing.

Therefore, the present invention is to solve the above conventional problems, by determining the weight of the sea animal using the initial temperature rise rate of the sea animal and then set the thawing temperature suitable for each weight to perform the thawing, the relationship between the initial temperature of the sea animal It is an object of the present invention to provide a defrosting apparatus for a microwave oven and a method for thawing the optimally thawed animal.

Microwave defrosting apparatus according to the present invention for achieving the above object, in the microwave oven including a turntable, a turntable motor, a magnetron, and a fan motor, the temperature of the sea animal placed on the turntable Temperature sensing means for sensing;

Calculate the initial temperature change rate of the sea animal by receiving the output of the temperature sensing means, calculate the weight of the sea animal from the initial temperature change rate, and set the thawing target temperature suitable for each weight so that the temperature of the sea animal reaches the thawing target temperature. It characterized in that it comprises a micom for controlling the turntable motor, the magnetron and the fan motor.

And, in the present invention, a microwave thawing method includes the steps of measuring the weight of the sea animal according to the rate of temperature change of the sea animal; Setting a first thaw target temperature and a second thaw target temperature according to the weight of the sea animal; Driving the magnetron at a first duty ratio to thaw the animal to a first thawing target temperature; Driving the magnetron at a second duty ratio to thaw the animal to a second thawing target temperature;

The magnetron is driven and defrosted by driving the magnetron at a third duty ratio for a predetermined time.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

2 is a schematic diagram of a microwave oven according to the present invention, which includes: a cooking chamber 26 having a turn table 24 for placing foods 22 therein; A turn table motor 28 for rotating the turn table 24; A magnetron 30 for supplying a high frequency into the cooking chamber 26; A fan motor 31 for ventilating air in the cooking chamber 26; Temperature sensing means (32) for sensing the temperature of the food (2) placed on the turn table (4); It is configured to include a microcomputer 34 for controlling the turn table motor 28, the magnetron 30, and the fan motor 31 in accordance with the output of the temperature sensing means (32).

At this time, the microcomputer 34 receives the output of the temperature sensing means 32, calculates the initial temperature change rate of the sea animal 22, calculates the weight of the sea animal 22 from the temperature change rate, and then The appropriate target temperature is set to control the turntable motor 28, the magnetron 30 and the fan motor 31 so that the temperature of the sea animal 20 reaches the thawing target temperature.

And, as shown in FIG. 3, the temperature sensing means 32 senses the temperature of the sea animal 20 and outputs a voltage proportional to the temperature of the sea animal 20. And an amplifier 32-2 for amplifying the voltage, and a band pass filter 33-2 for bandpass filtering the voltage output from the amplifier 32-2 and outputting the bandpass filter to the microcomputer 34. It is configured to include.

R1, R2, R3, R4, R5, and R6, which are not described above, are resistors, C is a capacitor, and OP-amp1 and OP-amp2 are op amps.

In the thawing apparatus of the microwave oven according to the present invention configured as described above, the method of thawing a sea animal, as shown in Figure 4, depending on the temperature change rate of the sea animal 22, the weight of the sea animal 22 Measuring step S10; Setting a first thaw target temperature T1 and a second thaw target temperature T2 according to the weight of the sea animal 22 (S20); Driving the magnetron 30 at a first duty ratio to thaw the sea animal 22 to a first thawing target temperature T1 (S30); Driving the magnetron 30 at a second duty ratio to thaw the sea animal 22 to a second thawing target temperature T2 (S40); The magnetron 30 is defrosted by driving the magnetron 30 with a third duty ratio for a predetermined time, and then ends (S50).

Measuring the weight of the sea animal 22 according to the rate of change of the sea animal 22 (S10), driving the turntable motor 28 and the fan motor 31 (S11) and the fan motor ( Measuring the initial temperature t1 of the sea animal 22 after a predetermined time after the 31 is driven (S12); Driving the magnetron 30 at a first duty ratio (S13); Determining whether the magnetron 30 has been driven for three or more cycles, and repeating the operation of driving the magnetron 30 with the first duty ratio (S13) if less than three cycles (S14); Measuring the temperature t2 of the sea animal 22 when the magnetron 30 has been driven for three or more cycles (S15); Calculating a temperature change rate? T of the sea animal 22 (S16); Comprising the step of calculating the weight of the sea animal 22 from the temperature change rate (Δt) (S17).

In operation S30 of driving the magnetron 30 at the first duty ratio to thaw the sea animal to the first thaw target temperature T1, the temperature of the sea animal 22 is the first thaw target temperature T1. Determining whether it is smaller (S31); Driving the magnetron 30 at a first duty ratio when the temperature of the sea animal 22 is smaller than the first thawing target temperature T1 (S32); Measuring the temperature of the sea animal 22 (S33); It is determined whether the temperature of the sea animal 22 is greater than or equal to the first thawing target temperature T1, and when the temperature of the sea animal 22 is less than the first thawing target temperature T1, the magnetron 30 is driven at a first duty ratio. It consists of a step S34 of repeating the step (S32).

In the step S40 of driving the magnetron 30 with the second duty ratio to thaw the sea animal 22 to the second thaw target temperature T2, the temperature of the sea animal 22 is the first thaw target temperature T1. Greater than or equal to) driving the magnetron 30 at a second duty ratio (S41); Measuring the temperature of the sea animal 22 (S42); It is determined whether the temperature of the sea animal 22 is greater than or equal to the second thawing target temperature T2, and when the temperature of the sea animal 22 is less than the second thawing target temperature T2, the magnetron 30 is driven at the second duty ratio. It consists of a step (S43) to repeat the step (S41).

In operation S50, the magnetron 30 is defrosted by driving the magnetron 30 at a third duty ratio for the predetermined time, and when the temperature of the sea animal 22 is greater than or equal to the second thawing target temperature T2, the magnetron at the third duty ratio (S50). 30) driving (S51); Determining whether the time defrosted by the third duty ratio is equal to or greater than the time defrosted by the second duty ratio, and when the time thawed by the third duty ratio is less than the time corresponding to the second duty ratio, driving the magnetron 30 at the third duty ratio. Repeating (S51) (S52); If the time thawed by the third duty ratio is equal to or more than the time thawed by the second duty ratio, the turntable motor 28, the magnetron 30, and the fan motor 31 are stopped (S53).

In this case, the first duty ratio is 30 seconds and the magnetron 30 is driven for 10 seconds and then stopped for 20 seconds, and the second duty ratio is 30 seconds and the magnetron 30 is 7 seconds. The third duty ratio has a period of 30 seconds, and the magnetron 30 is driven for 4 seconds and then stopped for 26 seconds.

Referring to the operation and effect of the thawing apparatus and the thawing method of the microwave oven according to the present invention as described above in detail.

After the sea animal 22 is placed in the cooking chamber 26 and the thawing starts, the microcomputer 34 operates the turntable motor 28 to rotate the turntable 24 and the sea animal 22. Then, the fan motor 31 is driven to circulate the air in the cooking chamber 26 (S11).

The reason for driving the fan motor 31 as described above is that the infrared sensor 32-1 incorrectly detects the initial temperature t1 of the sea animal 22 by the air temperature in the cooking chamber 26 that is heated. This is to prevent.

Subsequently, after operating the turntable motor 28 and the fan motor 31 for a predetermined time (about 30 seconds), the temperature of the sea animal 22 is sensed and the temperature is converted to the initial temperature t1 of the sea animal 22. (S12)

Subsequently, the marine animals 22 in the cooking chamber 26 are driven at a high frequency generated by the magnetron 30 by driving the magnetron 30 at a first duty ratio (cycle 30 seconds, 10 seconds 'on', 20 seconds 'off'). (S13)

Subsequently, after a predetermined time (3 cycles as the first duty ratio), the temperature t2 of the sea animal is detected at the time when the magnetron 30 is stopped (S14, S15).

That is, the signal sensed by the infrared sensor 32-1 is affected by the driving state of the magnetron 30 and the rotation of the turntable 24, and thus, a predetermined time (at least a turntable (at least) when the magnetron 30 is stopped. 24) the temperature of the sea animal (t2) is detected by sensing the infrared signal for more than one time) and averages it.

Subsequently, the initial temperature t1 of the sea animal 30 is subtracted from this temperature t2 to calculate the temperature change rate (Δt = t2-t1) (S16).

Subsequently, the weight of the sea animal 22 is calculated using the temperature change rate? T.

That is, as shown in FIG. 5, the larger the weight of the marine animal 22 is, the smaller the rate of change of temperature (Δt) of the marine animal 22 is. That is, the temperature change rate (Δt) of the sea animal 22 is smaller when the sea animal 22 is 1000g than when the sea animal 22 is 300g.

Therefore, the weight of the sea animal 22 can be calculated using the temperature change rate (DELTA) t of the sea animal 22 initially.

After the weight of the sea animal 22 is calculated as described above, the first thawing target temperature T1 and the second thawing target temperature T2 are set according to the weight of the sea animal 22. (S20 )

The reason why the thawing target temperatures T1 and T2 are different depending on the weight of the sea animal 22 is that the temperature rise is different depending on the site of the sea animal 22 due to the uneven distribution of the electric field in the cooking chamber 26. .

That is, the heating of the corners and the bottom is faster than the top surface of the sea animal 22, and the infrared sensor 32-1 determines the thawing state by using the top surface temperature of the sea animal 22, so that the longer the thawing time is, This is because the higher the weight, the greater the chance of overcooking the edges and bottoms.

Subsequently, the magnetron 30 is driven at a first duty ratio (cycle 30 seconds, 10 seconds 'on', 20 seconds 'off') until the temperature of the sea animal 22 is greater than the first thawing target temperature T1. (S31, S32, S33, S34)

Subsequently, the magnetron 30 is driven at a second duty ratio (cycle 30 seconds, 7 seconds 'on', 23 seconds 'off') until the temperature of the sea animal 22 is greater than the second thawing target temperature T2. (S41, S42, S43)

Subsequently, the magnetron 30 is driven at a third duty ratio (cycle 30 seconds, 4 seconds 'on', 26 seconds 'off') for a predetermined time, and then the turntable motor 28, the magnetron 30 and the fan motor 31 are driven. Stop).

In this case, the driving period of the magnetron 30 at the third duty ratio is the same as the driving period of the magnetron 30 at the second duty ratio.

That is, as shown in FIG. 6, in the mode 1 during which the initial temperature of the sea animal 22 is measured, the magnetron 30 is not driven and only the fan motor 31 is driven.

In addition, the magnetron 30 and the fan motor 31 are both driven in Mode 2, which is a period in which the magnetron 30 is driven at a first duty ratio (cycle 30 seconds, 10 seconds 'on', 20 seconds 'off'). .

In addition, the magnetron 30 and the fan motor 31 are both driven in mode 3, which is a period in which the magnetron 30 is driven at a second duty ratio (cycle 30 seconds, 7 seconds 'on', 23 seconds 'off'). .

In mode 4, which is a period in which the magnetron 30 is driven at a third duty ratio (30 seconds, 4 seconds 'on', 26 seconds 'off'), both the magnetron 30 and the fan motor 31 are driven.

As described above, after the mode 4 passes, both the magnetron 30 and the fan motor 31 are stopped.

As described above, according to the present invention, by determining the weight of the sea animal using the initial temperature rise rate of the sea animal, by performing the thawing by setting the thawing temperature suitable for each weight, the sea animal is optimal regardless of the initial temperature of the sea animal It can be thawed.

Claims (14)

A microwave oven comprising a turntable, a turntable motor, a magnetron, and a fan motor, comprising: temperature sensing means for sensing a temperature of a sea animal placed on the turntable; Calculate the initial temperature change rate of the sea animal by receiving the output of the temperature sensing means, calculate the weight of the sea animal from the initial temperature change rate, and set the thawing target temperature according to the calculated weight, and according to the set thaw target temperature And a microcomputer for controlling the marine animal to reach the thawing target temperature by driving the magnetron while adjusting the driving duty ratio. 2. The apparatus of claim 1, wherein the temperature sensing means comprises: an infrared sensor for sensing a temperature of the sea animal and outputting a voltage proportional to the temperature of the sea animal, and an amplifier for amplifying the voltage; And a band pass filter configured to band pass filter the voltage output from the amplification unit and output the band pass filter to the microcomputer. Measuring the weight of the sea animal according to the rate of change of the initial temperature of the sea animal; Setting a first thawing target temperature and a second thawing target temperature according to the weight of the sea animal; Driving the magnetron at a first duty ratio to thaw the animal to a first thawing target temperature; Driving the magnetron at a second duty ratio to thaw the animal to a second thawing target temperature; A method of thawing a microwave oven, characterized in that the step of driving the magnetron at a third duty ratio for a predetermined time and then thawing. 4. The method of claim 3, wherein the first duty ratio is 30 seconds, the magnetron is driven for 10 seconds, and then stopped for 20 seconds. 4. The method of claim 3, wherein the second duty ratio is 30 seconds, the magnetron is driven for 7 seconds, and then stopped for 23 seconds. 4. The method of claim 3, wherein the third duty ratio is 30 seconds, the magnetron is driven for 4 seconds, and then stopped for 26 seconds. The method of claim 3, wherein the measuring of the weight of the sea animal according to the initial temperature change rate of the sea animal comprises: driving a turntable motor and a fan motor; Measuring an initial temperature of the sea animal after a predetermined time after the fan motor is driven; Driving the magnetron at a first duty ratio; Determining whether the magnetron has been driven for a predetermined time or more and repeating the operation of driving the magnetron with the first duty ratio if it is less than a predetermined time; Measuring the temperature of the sea animal when the magnetron has been driven for a predetermined time; Calculating a rate of change of the marine animal; The thawing method of the microwave oven, characterized in that consisting of calculating the weight of the sea animal from the rate of change of temperature. The method of claim 7, wherein the initial temperature of the sea animal is measured after a predetermined time after the fan motor is driven, wherein the initial temperature of the sea animal is measured 30 seconds after the fan motor is driven. Way. The method of claim 7, wherein the step of determining whether the magnetron has been driven for a predetermined time or more and repeating the operation of driving the magnetron with the first duty ratio if it is less than a predetermined time determines whether the magnetron has been driven for three or more cycles at the first duty ratio. Less than 3 cycles, the method according to claim 1, wherein the magnetron is driven at the first duty ratio. The method of claim 7, wherein the calculating of the weight of the sea animal from the rate of temperature change comprises calculating the weight of the sea animal from the temperature change rate according to a correlation characteristic between the temperature change rate and the weight of the sea animal. . 4. The method of claim 3, wherein the thawing of the sea animal to the first thawing target temperature by driving the magnetron at the first duty ratio comprises: determining whether the sea animal temperature is less than the first thawing target temperature; Driving the magnetron at a first duty ratio if the temperature of the sea animal is less than the first thawing target temperature; Measuring the temperature of the sea animal; Determining whether the temperature of the sea animal is greater than or equal to the first thawing target temperature, and repeating the step of driving the magnetron at a first duty ratio if the sea animal temperature is less than the first thawing target temperature. . 4. The method of claim 3, wherein the driving of the magnetron at the second duty ratio to thaw the sea animal to the second thawing target temperature comprises: driving the magnetron at the second duty ratio if the temperature of the sea animal is greater than or equal to the first thawing target temperature; ; Measuring the temperature of the sea animal; Determining whether the temperature of the sea animal is the second thawing target temperature, and if the temperature of the sea animal is less than the second thawing target temperature, repeatedly driving the magnetron with the second duty ratio. Way. 4. The method of claim 3, wherein the driving of the magnetron at a third duty ratio for thawing and then terminating the magnetron comprises: driving the magnetron at a third duty ratio when the temperature of the sea animal is greater than or equal to the second thawing target temperature; Determining whether a predetermined time has elapsed and repeating the step of driving the magnetron with the third duty ratio if the predetermined time has not elapsed; After the predetermined time has elapsed, a method of thawing the microwave oven, characterized in that the step consisting of stopping the turntable motor, the magnetron and the fan motor. The method of claim 13, wherein the determining whether the predetermined time has elapsed comprises: determining whether the time defrosted by the third duty ratio is equal to or longer than the time defrosted by the second duty ratio, and the time defrosted by the third duty ratio is the second duty ratio. When the thawing time is less than the thaw method of the microwave oven characterized in that the magnetron is driven at the third duty ratio.