JPH01107021A - Heating control method for microwave oven - Google Patents

Abstract

PURPOSE:To enable proper control of heating, by a method wherein, in control of heating, the upper and the lower limit value of the output value of a temperature sensor are set, and only the output value of the temperature sensor enters a region between the upper and the lower limit valves is processed as an effective value. CONSTITUTION:When a frozen food is thawed, after making of a power supply ON, a key input is first detected. When a key input to instruct a course except a thawing course is effected, transfer to other processing is executed. When a key input to instruct the thawing course is effected, waiting for control of start key is made, and when a start key is controlled, a finish temperature TO, an upper limit temperature TH, and a lower limit temperature TL are respectively set. A counter K1 to display the number of temperature measuring times and a counter K2 to display the number of times which temperature measurement does not range between the upper and lower limit values TH and TL are set to 0, and a content M of a memory to accumulate measurement data is cleared. Thereafter, a timer is set to, for example, 5sec, a magnetron is heated for 5sec in succession resulting from turn ON of a switch, and the magnetron is turned OFF after a lapse of 5sec.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention has a turntable for placing food in the refrigerator, detects the temperature of the food using a temperature sensor, and heats the food based on the detected temperature. The present invention relates to a heating control method in a microwave oven that controls conditions.

<Prior Art> Conventionally, microwave ovens have been provided that include an infrared temperature sensor and control microwave oscillation conditions based on the detected temperature of the food to cook the food.

When measuring the temperature of food by placing the food on the rotating turntable in the microwave oven mentioned above, N temperature sensor output values are taken in for a predetermined period of time, and the average value of these N temperature sensor output values is calculated. A heating control method has been proposed in which one piece of temperature data is obtained by taking the maximum value or the minimum value, and heating control is performed based on this temperature data (Japanese Patent Laid-Open No. 5 [1-45593]). reference).

<Problems to be Solved by the Invention> However, in general, food temperature detection in a heating device such as a microwave oven may be affected by external noise. In other words, the sensor detects external noise,
At a certain moment, a temperature higher than the actual food temperature may be detected.

Further, for example, if the food is not placed at the center of the turntable, the correct temperature of the food may not be measured and an unexpected temperature sensor output value may be obtained.

In the above cases, the reliability of the obtained data also decreases,
A problem arises in that appropriate heating control cannot be performed.

Purpose of the Invention The present invention was made in view of the above problems, and provides a heating system that can correctly evaluate the temperature of food and perform appropriate heating control even when an unexpected temperature sensor output value is obtained. The purpose is to provide a control method.

Means for Solving the Problems> In order to achieve the above object, the heating control method in a microwave oven of the present invention sets an upper limit value and a lower limit value of the temperature sensor output value, and sets an upper limit value and a lower limit value of the temperature sensor output value. In this method, only the temperature sensor output value between 1 and 2 is used as an effective value for heating control.

According to the heating control method with the above configuration, an upper limit value and a lower limit value of the sensor output value are set, and only the temperature sensor output value that falls between the upper limit value and the lower limit value is processed as valid. Since the temperature sensor can be used for heating control inside the refrigerator, unexpected temperature sensor output values can be eliminated.

<Example> Next, an example of the present invention will be described below with reference to the drawings.

Figure 2 is a cross-sectional view of the microwave oven, and Figure 3 is a block diagram showing a simple configuration of the heating control circuit.
has a built-in magnetron (6) that heats the inside of the refrigerator (2), and a turntable (1
2) is equipped with an infrared sensor (3) that detects the temperature of the food (7) placed on top, and a keyboard section (4) equipped with instruction keys and a display section for instructing cooking procedures (see Figure 3). is placed in the front. In addition, the temperature detection signal of the infrared sensor (3) and the code signal representing the instruction content of each instruction key are input to the microcomputer (5), and the microcomputer (5) supplies an oscillation control signal to the magnetron (6). A display signal is supplied to the display section (8), and a signal for instructing a predetermined message is also supplied to the sound generation section (9). The message audio signal output from the audio generator (9) is amplified by the amplifier (]0) and sent to the speaker (11).
) is emitted as a sound. Note that the microcomputer (5) is equipped with a predetermined timer.

A flowchart (Figure 1) shows the heating procedure for thawing frozen food using this microwave oven (1) as an example.
The explanation will be based on.

After the power is turned on, first, key human power is detected in step S1. If there is a key human power to instruct a course other than the defrosting course in step S2, the process moves on to other processes.

If there is a key input to instruct the defrosting course in step S2, the process waits for a start key operation in step S3. When the start key is operated, the finishing temperature To (the temperature at which heating is stopped when it is determined that the defrost has been thawed) and the upper limit temperature Tl
+ (here 10℃), lower limit temperature TL (here -
20°C) are set to 5- (step S4).

Then, set 1 to a counter indicating the number of temperature measurements and 2 to a counter indicating the number of times the temperature was not within Hl between the upper limit temperature TH and lower limit temperature TL, and store the measured data in the memory. Clear the contents M (step S5). Next, set the timer to, for example, 5 seconds (step S6) and continue heating the magnetron (6) for 5 seconds with the switch ONL (steps 87 to 6).
s9), and when 5 seconds have elapsed, the magnetron (6) is turned off (step 5IO) (as shown in FIG. 1(A)).

Then set the timer to say 10 seconds in step 5.
11), reset the measurement check flag Fo (step 512). The timer is counted down (step 813), it is confirmed that the flag Fo has been reset (step 514), and the temperature is measured every second (step 515). When one temperature measurement is completed, the counter is incremented by 1 (step 516), and whether the measured temperature Tk is lower than the upper limit temperature T11 (step ■),
-6= It is determined whether the temperature is higher than or equal to the lower limit temperature TL (step @), and if it is between the upper limit temperature T11 and the lower limit temperature TL, the measured temperature Tk is added to the memory M (step 520). If the temperature is not between the upper limit temperature TI and the lower limit temperature TL, the temperature is not stored in the memory, but instead the counter is incremented by 2 (step 519). Then, the above steps 813 to S20 are repeated until the number of measurements reaches 10, and when the number of measurements reaches 10 in step S21,
That is, when the counter reaches 10, the measurement check flag Fo is set (step 522), and the process proceeds to the next temperature measurement data processing procedure (see FIG. 1(B)).

To summarize the above procedure, the frozen food is first heated for 5 seconds, then the heating is stopped for 10 seconds, and the temperature is measured every second during this stop. If each measured temperature falls between the upper limit temperature Tl+ and the lower limit temperature TL, the measured temperature is
Stored in memory as data. If the temperature does not fall between the upper limit temperature TH and the lower limit temperature TL, 2 is counted as the number of times the temperature falls between the upper limit temperature TI and the lower limit temperature TL.

In the next temperature measurement data processing procedure, 2 is evaluated in the counter. That is, if K2 is 8 or more times (step 823), it is determined that the sensor is malfunctioning, and a voice announcement is made that "the sensor needs repair" (step 524).

If K2 is less than 8 times and 5 times or more (step 525), it is determined that the food is not placed in the center of the turntable, and an announcement is made saying "Please place the food in the center" to call for attention (step 526). . In either case, the process returns to step 531) where a heating completion indication is displayed. If 2 is less than 5 on the counter, the process moves to step S27, and the number of times the measured value falls between the upper limit temperature TH and the lower limit temperature TL is n=
1 - 2 is calculated, the total M of measured values stored in the memory is divided by n, and the average value <M> is calculated (Step 5
28). If the average value <M> is equal to or higher than the finishing temperature To, it is determined that thawing has been achieved, a heating completion display is displayed (step 531), and the process returns to the start. If the average value <M> is less than the finishing temperature To, the process moves from step S29 to step S30, and it is checked whether 10 seconds have elapsed on the timer. In this case, since it has been confirmed in step S21 that the number of temperature measurements has passed 10 times, the timer should have counted up.
The determination result in step S30 is YES. Therefore, the process returns to step s5, and heating for 5 seconds and temperature measurement 10 times are performed again. In this way, heating and temperature measurement are repeated until the average value <M> becomes equal to or higher than the finished temperature To. Note that at the stage of step S30,
If the 10 measurements are completed early and the timer has not counted 10 seconds, the process returns to step 313.

Then, when the process moves to step S14, it is found that the flag Fo has already been set, so the process moves to step S30 again. In this way, steps S30, 13, and 14 are repeated until the timer is up (FIG. 1(C)).

To summarize the above procedure, count the number of times the measured temperature did not fall between the upper limit temperature T11 and the lower limit temperature TL, and if the number of times is greater than a predetermined number, it is determined that the food is not placed in the center of the turntable. If the number of occurrences is extremely large, it is determined that the sensor is malfunctioning and the respective cooks are notified. If the number of times the measured temperature does not fall within the upper limit temperature TH and lower limit temperature TL is less than a predetermined number of times, it is determined that thawing has been successfully performed, and no further heating is performed, and a heating completion indication is displayed. .

Note that this invention is not limited to the above-mentioned embodiments, and can be applied not only to thawing frozen foods, but also when heating foods to high temperatures, for example, when the temperature sensor output value is between the upper limit value and the lower limit value. Heating control can be performed by employing only this value as an effective value. Although the arithmetic average of the temperature sensor output values is taken as the data for heating control, 1, a moving average, a weighted average, a maximum value, a minimum value, etc. may be taken. Various other changes can be made without departing from the gist of the invention.

<Effects of the Invention> As described above, according to the heating control method of the present invention, an upper limit value and a lower limit value of the sensor output value are set, and only the temperature sensor output value that falls between the upper limit value and the lower limit value is set. is processed as a valid value and used for heating control inside the refrigerator. Therefore, it is possible to eliminate the misalignment of the positional relationship between the food and the sensor observation unit due to the rotation of the turntable and the influence of external noise, making it possible to always obtain a normal temperature sensor output value and perform accurate heating control. It has a unique effect.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing a control procedure according to the heating control method of the present invention, FIG. 2 is an internal sectional view of a microwave oven, and FIG. 3 is a schematic diagram of an electric circuit related to the heating control method.

Claims (1)

[Claims] 1. Install a turntable for placing food inside the refrigerator. It has a temperature sensor that measures the temperature of the food. Detects and microwaves based on detected temperature Heating control system that controls the heating conditions of control method, above the temperature sensor output value. Set a limit value and a lower limit value, and The temperature sensor output value between the lower limit value is adopted as an effective value and used for heating control. In a microwave oven characterized by heating control method. 2. Thawing food through heating control The microwave oven according to claim 1 Heating control method for heating.