JPS63207921A - Electronic range - Google Patents

Abstract

PURPOSE:To prevent even a packaged food from being overheated to carry out optimum cooking by continuing heating 1-2 times the time passing from the start of heating to a detection time point when the standstill of the temperature rise or the temperature fall is detected by an infrared ray sensor. CONSTITUTION:After starting the heating, a predetermined period DELTAT is set, and thereby whether the rise in the temperature detected by an infrared ray sensor is in standstill or the temperature falls or not, is judged. If the rise in the temperature is not in standstill or the tempperature does not fall, the judging procedure is repeated. If the temperature is kept on rising until the temperature reaches a cooking temperature thetam, heating is then stopped after the elapse of a time K1T1. If the rise in the temperature is in standstill or the temperature falls even once until the temperature reaches the cooking temperature thetam, the heating is continued over a period of time K2T2 which is K2 times the time T2 passing from the start of heating to a time at which the standstill or fall has been detected. By this procedure, even if the food has a tendency shown by either of curves A and B, the heating control can be carried out automatically in accordance with the food.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention detects food temperature using an infrared sensor,
The present invention relates to a microwave oven that controls heating conditions using microwaves based on detected temperature.

<Prior Art> Conventionally, microwave ovens have been provided that are equipped with an infrared temperature sensor and heat food by controlling the time of microwave oscillation based on the detected temperature.

In the above microwave oven, the temperature near the surface of the food is detected by an infrared sensor, and when the detected temperature reaches the cooking temperature, the time required to reach this cooking temperature is further calculated to achieve the desired finished food state. The oscillation is stopped after heating is continued for a predetermined time period corresponding to the amount of time.

According to this microwave oven, it is possible to cook food to an optimal finished state without a large difference between the temperature near the surface of the food and the internal temperature.

<Problems to be Solved by the Invention> However, recently, foods that are heated and cooked in a microwave oven (packaged foods) have become popular.

When such a packaged food is heated in the microwave oven, the finished state of cooking may change depending on the moisture content of the packaged food, the material of the package, etc.

In particular, the above tendency is remarkable when a paper container is used for the □ package.

Considering the reason for this, for example, when a cake in a paper container is heated, the temperature near the surface of the packaged food increases at one point (a), as shown by curve (B) in Figure 4. May show stagnation or temperature drop. This is thought to be because the cake contains a large amount of water, which moistens the container and prevents the temperature near the surface of the container from rising due to the heat of vaporization.

Therefore, for packaged foods that exhibit a stagnation in temperature rise or a temperature drop, the time it takes to reach the cooking temperature is longer. If heating is continued, even if the finished quality can be adjusted to some extent by adjusting the predetermined magnification, there is a problem in that the overall heating tends to be excessive.

<Object of the invention> This invention was made in view of the above problems,
The purpose of the present invention is to provide a microwave oven that can cook packaged foods to a desired finished state.

Means for Solving the Problems〉 The microwave oven of the present invention for achieving the above object has the following features:
If a stagnation in temperature rise or a temperature drop is detected based on the temperature detected by the infrared sensor during the time from the start of heating until the predetermined cooking temperature is reached, the elapsed time from the start of heating to the point of detection is multiplied by 1 to 2. The apparatus is equipped with heating control means that continues heating for a certain period of time from the time of detection.

With the microwave oven configured as above, if a temperature rise, stagnation, or temperature drop is detected based on the temperature detected by the infrared sensor after the start of heating and before the specified cooking temperature is reached, the microwave oven will start heating. The elapsed time until the detection point is 1 to
By continuing to heat for twice the time, even packaged food in a container will not be overheated and optimal cooking can be achieved.

<Example> Hereinafter, embodiments will be described in detail with reference to the accompanying drawings showing examples.

Figure 2 is a cross-sectional view of the microwave oven, and Figure 3 is a block diagram showing the circuit configuration of the microwave oven.The electronic oven (1) has a built-in magnetron (6) that heats the cooking chamber (2). An infrared sensor (3) for detecting the temperature of the food (7) is installed at a predetermined position on the ceiling side of the heating cooking chamber (■), and a cooking content (food) instruction key (41), a cooking start key (42), and a finish adjustment key are installed. A keyboard (4) having a keyboard (43) and the like is arranged on the front surface. The cooking content instruction key (41) is used to set the cooking temperature θm according to the type of cooked food, and the finish adjustment key (43) is used to set the coefficient KI according to the finish of the food, regardless of the type of cooked food. SK2 is set at the same time.

In addition, the temperature detection signal of the infrared sensor (3), keys (41) to (43), and code signals representing instruction contents are input to the microcomputer (5), and the oscillation control signal from the microcomputer (■) is input to the microcomputer (5). Magnetron (6)
is supplied to. Note that the microcomputer (5) is equipped with a predetermined timer.

The heating procedure in this microwave oven (1) will be explained based on the flowchart (FIG. 1).

When the cooking content instruction key (41) and finish adjustment key (43) are adjusted according to the cooking content and the desired finish of the cooking (step ■), the microcomputer (■) reads the instruction content and adjusts the cooking content and the desired finish of the cooking. Set the cooking temperature θm and coefficient KI SK2 corresponding to (step ■)
. After that, operate the cooking start key (42) (Step ■), oscillate the magnetron ■ (Step ■) to heat the food, and operate the infrared sensor (3) (Step 1.B ■) to measure the temperature. , let the measured temperature be θl
(Step ■). Then, set the measurement number n-1 (step ■), operate the timer (step ■), determine whether the measured time T exceeds ΔT (for example, 10 seconds), and measure the temperature again if it exceeds ΔT. and set the measured temperature as 02 (step [phase]).

After that, compare θ2 and θ1-Δθ (Step ■),
If θ2>θl−Δθ, it is determined that the detected temperature has not decreased, and the process proceeds to step @.

If θ2 - Δθ, it is determined that the detected temperature has fallen, and the process proceeds to step [Yes]. Here, Δθ is a positive value that is not zero (for example, 1° C.), and means a temperature drop value that is a reference for determining whether or not there has been a temperature drop.

In step @, the temperature θ1 is replaced with a value of 02. Then, it is determined whether θ1 has reached the cooking temperature θm, and if it has reached the cooking temperature θ■, that is, θ1>θI
If so, proceed to step (2) and set the time T at that point as TI. Thereafter, it is determined whether or not the measured time has exceeded Tl (1+KD), and if it has exceeded it, the magnetron and timer are turned off (step ■). temperature θ
If m has not been reached, increase n by 1 (step [Yes]
), returns to step (2), measures the temperature again, sets the measured temperature to θ2 (step (Ili))), and determines whether the detected temperature has decreased (step (2)).

If you proceed from step ■ to step [Yes],
It is determined that there has been a drop in the detected temperature, and the time T at this point is set as T2 (step @), and the measured time is 72 (1+
In step 2), determine whether or not it has exceeded step @), and if it has exceeded, turn off the magnetron and timer (step ■).

In the above procedure, Δθ was a constant positive value, but Δθ
It is also possible to set it as θ-0. In this way, even if there is no temperature change in step (2), step (2).

Since the process will proceed to [Yes], the heating continuation time can be controlled based on the stagnation of temperature rise or temperature drop.

In short, after the start of heating, after a certain period of time ΔT,
It is determined whether the temperature increase detected by the infrared sensor has stagnated or the temperature has decreased within the period, and if the temperature increase has not stagnated or the temperature has decreased, the next period is entered and the above determination procedure is repeated.

If the temperature continues to rise until it reaches the cooking temperature θm, the heating is stopped after a time period KITI (Tl is the time at which the cooking temperature θm is reached) has elapsed. Cooking temperature θm
If the temperature rise stagnates or the temperature drops even once until reaching , heating is continued for 2 T2, which is twice the elapsed time T2 from the start of heating to the time when the stagnation or drop is detected.

As a result, curves (A) and (B) (see Figure 4)
Regardless of which tendency the food has, heating control can be automatically performed in accordance with the food. For example, heating of different cooked foods such as porridge (having the characteristics of curve (A)) and cake (having the characteristics of curve (B)) can be controlled by one cooking content instruction key (41). In other words, if you want to adjust the doneness of cooking, press the finish adjustment key (4).
3) to set the coefficients to predetermined values of 1 and 2, thereby making it possible to adjust the finished quality of any of the above-mentioned cooked foods with a single key operation. In other words, if the operation position of the finish adjustment key (43) is set to, for example, 1 a little less (heating is less), the coefficients Kl and 2 are each set to predetermined values, and for any of the above-mentioned cooked foods. However, it can be cooked to a soft texture. Therefore, it can be expected that the usability of the microwave oven will be improved.

In the above examples, when various packaged foods were heated and cooked as K2-1 and K2-2, the desired finish could be obtained. For example, if you set 2 near 1 above, the finish will be soft, and if you set it near 2, the finish will be hard. It was confirmed that the setting should be around 2-1.5 to achieve a medium finish. Moreover, variations in the finish quality depending on the food are reduced,
Previously it was 60%, but we were able to reduce it to less than 5%.

<Effects of the Invention> As described above, the present invention detects whether the increase in temperature detected by the infrared sensor stagnates or decreases for a certain period after heating starts and before reaching the cooking temperature, and detects whether the temperature increase is detected by the infrared sensor. If the temperature stagnates or the temperature drops, we decided to continue heating for a time that is 1 to 2 times the elapsed time from the start of heating to the point of detection. It has the unique effect of allowing food to be cooked to the desired state without overcooking even if the food is falling.

[Brief explanation of the drawing]

Fig. 1 is a flowchart explaining the heating procedure, Fig. 2 is a cross-sectional view of the microwave oven, Fig. 3 is a block diagram of the circuit configuration, and Fig. 4 is a graph showing changes in food temperature. (1)...Microwave oven, (3)...Infrared sensor, (5)...Microcomputer as heating control means Fig. 4 Time T Fig. 2 Fig. 3

Claims (1)

[Claims] 1. Check the temperature of food using an infrared sensor Detect and microwave based on detected temperature Microwave oven to control heating conditions by After heating starts, the specified cooking temperature is reached. the infrared sensor during the time until Based on the detected temperature, the temperature rise will stagnate or If a temperature drop is detected, heating will start. 1 to 2 times the elapsed time until the point of detection. Further additions are made from the point of detection for the amount of time specified. Equipped with heating control means to continue heating. A microwave oven characterized by. 2. The heating control means performs a predetermined adjustment after starting heating. The infrared sensor is turned off during the time it takes to reach the Detected temperature based on the temperature detected by the sensor stagnation or temperature drop. For example, from the start of heating until the cooking temperature is reached. For the time that is the predetermined times the elapsed time until Furthermore, the above-mentioned characteristics that continue heating A microwave oven according to claim 1.