JPS6352437B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to an automatic microwave oven having an automatic button, and in particular, it is intended to provide a method by which more menus can be automatically cooked using one automatic button. Conventional configurations and their problems Conventionally, methods for automatic cooking in microwave ovens using humidity sensors, infrared sensors, gas sensors, etc. have been proposed and have already been put into practical use.
However, in such conventional automatic microwave ovens, an automatic button is provided for each cooking menu, so the current situation is that a very large number of automatic buttons are arranged on the operation panel. Therefore, we cannot further expand the range of food menus that can be automated,
The drawback was that it felt very complicated for the user, making it difficult to use. Purpose of the Invention In view of these drawbacks, the present invention groups automatic buttons for each cooking menu.
The purpose is to provide a method for automatically cooking a large number of food menus with one automatic button, and to provide an easy-to-use automatic microwave oven. Structure of the Invention In order to achieve this object, the present invention provides a humidity detection means using a humidity sensor and a temperature detection means using an infrared sensor, etc. By detecting that the temperature has reached around ℃, and by detecting the temperature of the container containing the food as a substitute for the condition of the lower temperature part of the food using a temperature detection means, these two pieces of information and the start of heating can be detected. The idea is to automate heating by automatically calculating the additional heating time that should be continued based on the time required from the time to the humidity detection. First, before explaining the present invention in detail, let us explain why automatic buttons are provided for each cooking menu in conventional automatic microwave ovens, using an example of a humidity detection automatic microwave oven using a humidity sensor. Let me clarify. In general, the basic idea behind humidity-sensing automatic microwave ovens is that if t is the time from when heating starts until humidity is detected, then K is calculated by multiplying this time t by a unique constant K for each cooking menu. The cooking menu is automatically cooked by continuing the heating for t time. Therefore,
In conventional automatic microwave ovens, the value of the constant K is different for each food menu, so an automatic button is also provided for each food menu. Next, the unique constant K for each food menu mentioned above
Considering this, it is estimated that the main reason for this is uneven microwave heating caused by the shape of the food menu. That is, the shape of the food menu can be modeled as shown in FIG. 3, for example. In a cooking menu like the one in Figure 3A, each ingredient is finely detailed, and the penetration depth of the microwave (power half value)

[Formula] : Microwave frequency, ε _r : Relative permittivity of object,
Since it is small compared to tan δ (dielectric loss angle of the object), microwaves can easily hit the entire surface uniformly and there is less uneven heating. In a cooking menu like B, the size of one of the ingredients is larger than the penetration depth of the microwave, and the heating progresses differently between the outer layer and the center of the ingredient, resulting in uneven heating. In addition, a food menu like C is in liquid form, and the surface absorbs more microwaves. Therefore, convection is small near the center and large near the sides of the container, resulting in uneven heating. Furthermore, heating unevenness due to non-uniformity of electric field strength distribution within the oven, which is a cavity resonator, is superimposed. Due to these differences in the shape of the food menu,
Alternatively, uneven heating may occur due to uneven electric field strength distribution within the oven, and as heating progresses in some areas, water vapor or various component gases are released from those areas. Even when this is detected, there may still be some parts of the food menu that are not sufficiently heated. The constant K mentioned above can be considered as something that corrects uneven heating progress caused by such heating unevenness, and it can be estimated that the larger the heating unevenness is, the larger the constant K is. FIG. 4 schematically shows this situation. In other words, in the cooking menu, the place where heating progresses quickly is MAX.
It can be said that the larger the difference in the slope of the temperature rise curve at the slow point MIN is, the larger the constant K is. As is clear from the above explanation, if it is possible to detect the states of fast and slow heating progress, the constant K can be automatically generated from the difference in the temperature rise curves, and by this, the constant K can be adjusted for each dish menu. It is thought that it will be possible to group automatic buttons into one automatic button. DESCRIPTION OF EMBODIMENTS Based on this idea, specific embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a basic configuration diagram of the present invention, where 1 is a microwave oscillation source such as a magnetron, 2 is an oven, 3 is an object to be heated in the oven,
4 is the container, which is generally made of a low dielectric loss material. Reference numeral 5 denotes a microwave heating control means, which controls the supply of the microwave heating power source 7 to the microwave oscillation source by a signal from the main control means 6. Reference numeral 8 denotes a humidity sensor, which captures water vapor released from the object to be heated 3 that has been led to the exhaust duct 9. Reference numeral 10 denotes a ventilation fan, which serves to ventilate the inside of the oven 2 and to transport water vapor released from the object to be heated 3 to the exhaust duct 9 as exhaust air. The main control means 6 has a function of inputting the humidity information signal HUM from the humidity sensor 8 and detecting the progress of heating. Moreover, 11 is an infrared sensor, and oven 2
The inside of the oven 2 can be viewed through a detection window 2a provided on the bottom surface of the oven 2. Reference numeral 12 denotes a chopper device which serves to chop infrared rays radiated from the bottom of the container 4 containing the object to be heated in the oven 2 and input it to the infrared sensor 11. Next, the operation will be explained using FIG. 2. FIG. 2A shows how the humidity information HUM from the humidity sensor 8 changes over time, and FIG. 2B shows how the temperature information TEMP from the infrared sensor 11 changes over time. In addition, C is a place where the temperature of the heated object 3 increases quickly.
This is a schematic representation of the MAX and the slowest MIN. After heating starts, the temperature of the object to be heated 3 increases and the amount of water vapor released increases, and the HUM signal detected by the humidity sensor 8 increases with time. Moreover, the temperature of the bottom surface of the container 4 detected by the infrared sensor 11 also increases at the same time.
It rises over time as a TEMP signal. Eventually, the HUM signal reaches a predetermined humidity detection level. Let t be the time required from the start of heating to this point. In addition, the humidity detection level needs to be determined by taking a correlation so that when the HUM signal reaches this level, it can be assumed that the high temperature part of the heated object 3 has reached around 100°C. There is. In such a configuration, the rate of temperature rise over time in the portion where the temperature of the heated object 3 is fast is approximately
It should be possible to approximate it by 100/t. Next, the TEMP signal obtained by the infrared sensor increases almost linearly, and the slope of the temperature increase with respect to time is defined as a. At this time, it can be considered that the rate of temperature increase in the lower temperature part of the object to be heated 3 is correlated with that in the vicinity of the center of the bottom surface of the container. In particular, there is a strong correlation when the object to be heated 3 is liquid such as soup. On the other hand, considering that heating ends when the temperature of the entire object to be heated 3 becomes high, that is, when the temperature of the portion of the object to be heated 3 whose temperature rises slowly reaches around 100 degrees Celsius, for example, There is an idea to monitor when the TEMP signal obtained by the infrared sensor 11 reaches around 100℃, but
The signal does not measure the temperature of the part of the heated object 3 where the temperature rises slowly;
Naturally, there will be variations in the correlation value with the actual value due to differences in containers, differences in heated objects, differences in heating unevenness, etc. Therefore, in the present invention, instead of controlling the heating using the temperature of the bottom surface of the container 4 obtained by the infrared sensor itself, a method is adopted in which the temperature is used as an auxiliary method to automatically calculate the heating time. Based on this idea, the following calculation formula is proposed as one embodiment of the heating correction coefficient K. K= _C1 *100/t- _C2 *a+ _C3 However, _C1 , _C2 , and _C3 are all constants. Therefore, the total heating time can be determined by t·(1+K) using the heating correction coefficient described above, and heating can be automated. Effects of the Invention As explained in detail above, the present invention replaces the temperature rise rate of a portion of the heated object with a large temperature rise rate using data obtained by the humidity detection means, and
The temperature rise rate of the part of the object to be heated where the temperature rise rate is small is obtained as a correlation value by measuring the temperature of the container, and the heating time is automatically calculated using the heating correction coefficient using these values. This is an extremely practical invention that enables grouping of food menus, expanding new automated food menus, or simplifying automatic buttons as explained at the beginning.

[Brief explanation of the drawing]

Fig. 1 is a basic configuration diagram of the present invention, Fig. 2 is a diagram explaining the operation, Fig. 3 is a shape model diagram of a cooking menu, and Fig. 4 is a timing diagram schematically showing the progress of microwave heating. . 6... Main control means, 8... Humidity sensor, 11
...Infrared sensor.

Claims (1)

[Scope of Claims] 1. A food product comprising a humidity detection means for detecting water vapor released from food by heating and a temperature detection means for detecting the temperature of a container containing the food, and after the start of heating. , t is the time required for the water vapor released from the food to reach a predetermined amount and is detected by the humidity detection means, and the rate of temperature rise with respect to the time detected by the temperature detection means. When a, calculate the heating correction coefficient K from the calculation formula K= _C1・100/t− _C2・a+ _C3 (however, _C1 to _C3 are constants),
A high-frequency heating device that automatically calculates the total heating time as t・(1+K). 2. The high-frequency heating device according to claim 1, wherein an infrared sensor is used as the temperature detection means to detect the temperature of the bottom or side surface of the container in a non-contact manner.