JPS6120772B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an electronically controlled cooking appliance. In recent years, by using a microprocessor made of a semiconductor large-scale integrated circuit as a control means in a cooking appliance, it has become possible to perform various cooking functions with a simple circuit configuration and a simple operation procedure. One of such cooking functions is a cooking program function. According to this function, each cooking condition, such as heating energy intensity and heating time, is stored in advance in the storage unit of the cooker according to multiple cooking types, and when cooking, the heating energy intensity and heating time are stored in advance. Instead of having to set cooking conditions such as This is very convenient for the cook as there is no need to remember various cooking conditions or refer to a comparison table of cooking types and cooking conditions. However, in reality, even if the type of cooking is the same, the optimal cooking conditions will differ depending on the weight of the food to be cooked, but with the conventional cooking program function, even the weight of the food to be cooked can be input into the cooker. Therefore, as long as the type of cooking is the same, the cooking is done under the same cooking conditions regardless of the weight of the food, which is undesirable. Particularly when the heating energy is microwave, it is recognized that the heating state changes greatly depending on the weight of the object to be cooked. This is because the condition of the cooking chamber of the cooker determines the load when viewed from the microwave generation source, so if the condition of the cooking chamber changes depending on the weight of the food to be cooked, the condition of the cooking chamber and the microwave generation will change accordingly. This is because the impedance matching state with the source changes and the state of microwave energy supply to the cooking chamber changes. Therefore, an object of the present invention is to automatically input the weight of the food to be cooked into the cooker using the weight detection means in the cooking program function described above, and to perform more appropriate cooking with a simple operation. be. In the cooking program function, using the weight of the food to be cooked as a control condition means controlling the amount of heating energy supplied according to the weight of the food to be cooked, especially when the heating energy is microwave energy. , there is no direct proportional relationship between the weight of the food to be cooked and the appropriate microwave supply time. That is,
For example, just because the weight of the food to be cooked has doubled, it is not sufficient to simply double the microwave supply time. Accordingly, still another object of the present invention is to store the non-linear relationship between the amount of food to be cooked and the amount of heating energy supplied in advance in the storage section of the cooking device in the cooking program function. The aim is to set more appropriate cooking conditions according to the weight of the food. Still another object of the present invention is to simplify the circuit configuration by storing the cooking program and the non-linear relationship in the same storage unit. Still another object of the present invention is to save storage capacity by regarding the above non-linear relationship as common to all types of cooking. Still another object of the present invention is to achieve each of the above objects in a cooking program function that uses microwave energy as heating energy. The present invention will be explained in detail below with reference to Examples. Although the embodiments of the present invention are directed to microwave ovens, the present invention can also be effectively applied to other electric cooking appliances. FIG. 1 shows an electrical block circuit diagram of a microwave oven according to an embodiment of the present invention. 1 is the number keys from 0 to 9, WEIGHT,
A key operation section consisting of RECIPE, START, and STOP function keys and a contact type push button switch, and a display section 2 consisting of a well-known fluorescent numeric display tube.The display section and the operation section 1 will be described later. It is installed on the front right side of the microwave oven. 3
1 is a well-known microwave oscillation section consisting of a magnetron 4 and a half-wave voltage doubler rectifier circuit 5, and 6 is a weight detection circuit, which has the following configuration. That is, 7 and 8 are magnetoresistive elements, which are the second
As shown in the figure, it is disposed within the microwave oven main body 9 and is used to detect the weight of the food to be cooked 10.
That is, when the food to be cooked 10 in the container 13 provided in the cooking chamber 11 is placed, the mounting table 12 sinks against the spring 14 according to the weight of the food to be cooked 10, and at this time, the table 12 sinks against the spring 14, and at this time, the table 12 sinks against the spring 14. Since the opposing positions of the attached permanent magnet 15 and the magnetic resistance elements 7 and 8 are shifted, the resulting capacitance 1
The resistance values of the magnetoresistive elements 7 and 8 change depending on the weights of the magnet 3 and the food to be cooked 10. Reference numeral 16 denotes the two magnetoresistive elements 7 and 8 that change due to the resistance value change.
17 is an A/D converter that converts an analog signal from the amplifier circuit into a digital signal. Reference numeral 18 denotes a digital electronic control unit for controlling the operation of the microwave oven, and the control unit is composed of a microprocessor made of a semiconductor large-scale integrated circuit. The control section 18 inputs and processes the key signal from the key operation section 1 and the signal from the weight detection circuit 6, and controls the microwave oscillation of the microwave oscillation section 3. Note that the control section 18 also controls the timer display and weight display on the display section 2. 19 is a ROM configured in the control unit 18
(read-only memory), the ROM stores fixed cooking programs. Such a program is 1
This is for executing nine types of cooking from No. 9 to No. 9. For example, the cooking conditions for No. 1 and No. 2 are as shown in the following table.

[Table] That is, if, for example, No. 1 cooking is selected on the operation unit 1, heating cooking for 3 minutes is automatically executed at 80% of the maximum microwave output. The cooking conditions for each of the above cooking methods are based on the unit weight of the food being cooked (specifically,
200g). The ROM 19 further stores a coefficient program regarding the weight of the food to be cooked in the fixed cooking program. In a microwave oven, when the state of the cooking chamber changes due to the weight of the food to be cooked, the impedance matching state between the cooking chamber and the microwave source changes accordingly, and the amount of microwave energy supplied to the cooking chamber changes accordingly. Change. FIG. 3 shows the relationship between the weight of the object to be cooked and the amount of microwave energy supplied. This relationship is based on the magnetron 2M-172 manufactured by NEC Corporation (nominal output
600W) and a cooking chamber with a width of 374 mm, depth of 414 mm, and height of 248 mm, and water is selected as a typical cooking object. This is obtained by calculating the amount of microwave energy supplied. Looking at Figure 3, for example, the weight of the food to be cooked is 200
It can be seen that in the case of 800 g and 800 g, the amount of microwave energy supplied per unit time is 400 W and 615 W, respectively. This means that it is inappropriate to quadruple the heating time just because the weight of the food has quadrupled. In other words, when heating 200g of food for a time of _T1 , the total amount of energy _W1 supplied to the food is 400× _T1 , and therefore 800g.
If the same cooking state is to be obtained for the food to be cooked, the total amount of energy W ₂ required to be supplied to the food for that purpose is 4W ₁ since the weight is four times as large. On the other hand, if T ₂ is the required heating time to obtain 4W ₁ of energy, then W ₂ = 615×T ₂ ,
From these relational expressions, T ₂ =2.6T ₁ is obtained. That is, in the case of 800g, the heating time should be increased by 2.6 times compared to the case of 200g. The table below shows the elongation coefficient of heating time calculated for other weights based on the case of 200g.

[Table] In this embodiment, the above coefficients are commonly applied to all nine types of cooking in the fixed cooking program. Such a common application is practical since in all types of cooking, microwave energy is primarily absorbed by the moisture contained in the food being cooked. In addition, in this example, the amount of food to be cooked is based on 200g, and the amount up to 1800g is divided into 9 levels of quantity units according to the table above, but it can also be divided into multiple levels of quantity units. good. When the weight detection circuit 6 detects, for example, that the weight of the food to be cooked is 400 g, the control section 18 automatically changes the timer time by a coefficient of 1.6 corresponding to the weight of 400 g. Next, the cooking mode using the microwave oven of this embodiment will be explained. When executing fixed cooking program No. 1, first place the container 13 on the mounting table 12, and then use key operation 1 to Perform key operations in this order. At this time, a digital signal corresponding to the weight of the container 13, for example 150g, is input to the control unit 18 via the weight detection circuit 6, and the control unit 18 temporarily stores the weight information in the first weight register. Memory storage and display section 2
is displayed for a predetermined period of time (specifically, 2 seconds). Next, place the food to be cooked 10 in the container 13 on the placing table 12, and press the key operation unit 1. Perform key operations in this order. At this time, when the WEIGHT key is operated, the control unit 18 controls the second WEIGHT key operation.
It is determined that it is a key operation, the detected weight, for example 550g, is stored in the second weight register, and then the content of the first weight register (150g) is subtracted from the content of the second weight register (550g), and as a result, 400g, That is, the net weight of the food to be cooked is displayed on the display section 2 for 2 seconds. Then, by operating the STMRT key, fixed cooking program No. 1, which includes heating cooking for 3 minutes at 80% of the maximum microwave output, is read from the ROM 19, but this program has a unit weight of 200
Since it is inappropriate for the net weight of 400 g, it must be converted according to the coefficient program in the ROM 19. That is, the control section 18
The timer time of the cooking program No. 1 is multiplied by 1.6 and changed to 4 minutes and 48 seconds using a coefficient of 1.6 corresponding to 400g of the coefficient program. After that, the control unit 18 controls the microwave oscillation unit 3 to generate 4 minutes at 80% of the maximum microwave output.
Execute heating process for 48 seconds. In addition, the control unit 1
8 is 4 minutes 48 on the display section 2 during the cooking execution process.
The remaining time is displayed sequentially starting from seconds. Incidentally, in order to stop the execution of the cooking process in the middle, the user may operate the STOP key on the key operation unit 1. If the food to be cooked 10 is not placed in the container 13 but placed directly on the mounting table 12 for cooking, the key operation section 1 is used to Perform key operations in this order. In this case, the control unit 18
The weight information input into the first weight register by operating the WEIGHT key, that is, 400g, is
, and perform the same operations as described above. In the embodiment of the present invention, the ROM 19 is provided within the control section 18, but it may also be provided outside the control section 18, so-called externally. Furthermore, ROM19 is RAM (random access
It is also possible to replace it with other storage means such as memory). Further, in the embodiment of the present invention, the timer time is changed depending on the state of the food to be cooked 10, but it is also possible to change the output value. As is clear from the above description, the electronically controlled cooker of the present invention includes a weight detection means that automatically detects the weight of the food to be cooked, a first storage means that stores a plurality of cooking programs per unit weight, a second storage means for storing a non-linear relationship between the amount of food to be cooked and the amount of heating energy supplied; The weight of the food to be cooked is detected, and the desired cooking program is read from the first storage means, and the cooking conditions of the desired cooking program are adjusted to the second cooking condition with respect to the detected weight.
Since it is equipped with a control section that changes the contents according to the stored contents of the storage means, it is possible to perform extremely appropriate cooking according to the weight of the food to be cooked, and in this case, the operations include a weight detection operation and a cooking program readout operation. The operation can be extremely simplified.

[Brief explanation of the drawing]

Fig. 1 is an electrical block diagram of a microwave oven according to an embodiment of the present invention, Fig. 2 is a sectional view of the same microwave oven, and Fig. 3 is a curve diagram showing the relationship between the weight of the food to be cooked and the amount of microwave energy supplied. . 3...Microwave generator, 6...Weight detection circuit, 1
8...Digital electronic control unit, 19...ROM.

Claims (1)

[Claims] Weight detecting means for automatically detecting the weight of the food to be cooked; first storage means for storing a plurality of cooking programs per unit weight; and storing a non-linear relationship between the amount of the food to be cooked and the amount of heating energy supplied. Based on a second storage means, an operation section, and a weight detection operation and a desired cooking program reading operation on the operation section, the weight detection means detects the weight of the object to be cooked, and the desired cooking program is read from the first storage means. An electronically controlled cooking appliance characterized by comprising a control section for reading and changing the cooking conditions of the desired cooking program according to the stored contents of the second storage means for the detected weight.