JP3355493B2 - kitchenware - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooking utensil for automatic cooking or the like by detecting the temperature of food in a microwave oven, oven, grill or the like.

[0002]

2. Description of the Related Art Conventionally, this type of cooking utensil (here, a microwave oven) has been configured as shown in Japanese Patent Application Laid-Open No. 4-222321. Hereinafter, the configuration will be described with reference to FIG. As shown in the figure, a food 2 is placed on the bottom of the cooking chamber 1, and a heating means 3 composed of a magnetron that oscillates a microwave for heating to be introduced into the cooking chamber 1 is arranged outside the cooking chamber 1. Has been established. Above the cooking chamber 1, an infrared temperature sensor 4 for detecting the temperature of the food 2 is provided. In the cooking utensil configured as described above, the food 2
In the case of cooking, the microwave oscillated from the magnetron as the heating means 3 is introduced into the cooking chamber 2, the food 2 is heated and cooked by the introduced microwave, and the food 2 detected by the infrared temperature sensor 4 is cooked. The cooking is terminated when the temperature reaches a predetermined temperature.

[0003]

However, such conventional cooking utensils may not be able to accurately detect the food temperature.
When the temperature of the object to be measured by the infrared temperature sensor 4 changes suddenly, for example, immediately after the user puts the frozen food 2 into the cooking chamber 1 or the like, the user puts the frozen food at t0 as shown in FIG. Then, ideally, an output voltage change according to the temperature is instantaneously obtained as shown by a broken line a. However, in practice, the output voltage gradually decreases as shown by a solid line b and approaches the broken line a.
This is due to the effect that the temperature of the lens and the like decreases due to the absorbed infrared energy without passing through the lens of the infrared temperature sensor 4 and changes over a much longer time than the response of the sensor element. Until that time, the wrong temperature will be detected. Therefore, if the food 2 has a short cooking time, the cooking is completed at an incorrect temperature until the food 2 is balanced, and there are problems such as overcooking and undercooking.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem, and automatically detects the temperature of a food when the temperature of an object to be measured by an infrared temperature sensor changes rapidly, and completes the cooking in an appropriate finished state. With the goal.

[0005]

In order to achieve the above object, a cooking utensil according to the present invention comprises a cooking chamber for storing food, a heating means for heating food in the cooking chamber, and a temperature of food in the cooking chamber. An infrared temperature sensor that generates a voltage according to the following: a differentiator that detects a change in voltage generated from the infrared temperature sensor; a sensor temperature detector that detects the temperature of the infrared temperature sensor; and an output of the infrared temperature sensor. Voltage and the output of the differentiator.
A food initial temperature calculator for estimating the pressure, calculating the initial temperature of the food from the estimated convergence voltage and the output of the sensor temperature detector, and heating control for controlling the heating means with the output of the food initial temperature calculator The provision of a vessel is a first problem solving means.

Further, the cooking utensil of the present invention comprises a cooking chamber for storing food, a timer which is activated when the food is stored in the cooking chamber, heating means for heating the food in the cooking chamber, and a temperature of the food in the cooking chamber. An infrared temperature sensor that generates a voltage according to the following: a differentiator that detects a change in voltage generated from the infrared temperature sensor; a sensor temperature detector that detects the temperature of the infrared temperature sensor; and an output of the infrared temperature sensor. The output voltage by the voltage and the output of the differentiator
A food temperature calculator for calculating the food temperature from the estimated convergence voltage , the output of the sensor temperature detector and the output of the timer, and the heating means based on the output of the food temperature calculator. The provision of a heating controller for controlling is a second problem solving means.

[0007]

According to the first aspect of the present invention, when, for example, frozen food is put in a cooking chamber, the infrared temperature sensor outputs a voltage corresponding to the food temperature, and the differentiator sets a sharp temperature. The sensor temperature detector detects the temperature of the infrared temperature sensor, and the food initial temperature calculator calculates the convergence voltage of the output of the infrared temperature sensor from the output of the infrared temperature sensor and the output of the differentiator. The initial temperature of the food is calculated from the output of the temperature detector, and the heating controller controls the heating means based on the initial temperature of the food.

In the second means for solving the problems, the infrared temperature sensor outputs a voltage according to the food temperature, the differentiator detects a rapid temperature change, and the sensor temperature detector detects the temperature of the infrared temperature sensor. Then, the food temperature calculator calculates the convergence voltage of the output of the infrared temperature sensor from the output of the infrared temperature sensor and the output of the differentiator, and calculates the initial temperature of the food from the output of the sensor temperature detector. Further, the food temperature calculator calculates the temperature of the food every moment based on the output of the timer and the infrared temperature sensor and the initial temperature of the food, and the heating controller controls the heating means based on the calculation result.

[0009]

【Example】

Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. The same components as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, an example in which the present invention is applied to a microwave oven as a cooking appliance will be described. In FIG.
The infrared temperature sensor 4 generates a voltage between the contacts according to the temperature difference due to the joining of dissimilar metals, and detects the temperature difference between the temperature of the hot junction, ie, the food 2 inside, and the temperature of the cold junction, ie, the temperature of the infrared temperature sensor 4. A corresponding output voltage is generated.
The sensor temperature detector 5 is composed of a thermistor or the like and is attached to the cold junction of the infrared temperature sensor 4. The sensor temperature detector 6 detects the temperature of the cold junction of the infrared temperature sensor 4 based on the signal of the sensor temperature detector 5. I do. The output voltage of the infrared temperature sensor 4 is amplified by the amplifier circuit 7 and digitized by the AD converter 8. The voltage of the digital value obtained from the AD converter 8 is processed by the differentiator 9 to output a voltage change per unit time. The food initial temperature calculator 10 calculates the temperature of the food 2 based on the output of the sensor temperature detection circuit 6, the output of the AD converter 8, and the output of the differentiator 9. In addition,
Reference numeral 11 denotes a turntable which rotates to uniformly heat the food 2. The weight sensor 12 includes an electrode, a strain gauge, and the like. The weight G of the food 2 is detected by a weight detection circuit 13 based on a signal from the weight sensor 12. The operation circuit 14 is a circuit for outputting a signal in accordance with a user's instruction, and receives signals from the food initial temperature calculator 10, the weight detection circuit 13, and the operation circuit 14 and controls the heating controller 15 to operate the magnetron as the heating means 3. It controls the driving. When the user places the food 2 in the cooking chamber 1 and places it on the turntable 11 and instructs the start of cooking by the operation circuit 14, the heating controller 15 transmits information on the initial temperature T0 of the food 2 from the food initial temperature calculator 10. Receiving the information on the weight G of the food 2 from the weight detection circuit 13 and calculating the cooking time ts as ts = A · {(Ts−T0) · G} + B (Equation 1), and the heating means 3 is used for that time. The cooking is completed by driving the magnetron. Here, Ts is a predetermined set temperature, and A and B are predetermined constants. Also Ts
May be set by the user using the operation circuit 14. Depending on the initial temperature T0 of the food 2, for example, the temperature of the frozen food is suitable for thawing; It may be determined.

Next, the operation of the food initial temperature calculator 10 will be described. A signal corresponding to a temperature difference between the temperature of the food 2 obtained from the AD converter 8 and the temperature of the infrared temperature sensor 4;
By adding the temperature of the cold junction obtained from the sensor temperature detector 5, that is, the signal corresponding to the temperature of the infrared temperature sensor 4, the temperature of the food 2 can be calculated. However, in the case immediately after the frozen food is put in the cooking chamber as shown in FIG. 7, the output voltage of the infrared temperature sensor 4 approaches the ideal output voltage over a long time as shown by the solid line b. The output of the AD converter 8 is a signal obtained by amplifying and digitizing the output voltage of the infrared temperature sensor 4 by the amplifier circuit 7 and has a similar response characteristic. This response can be approximately approximated by the following equation. is there.

V = {C + (1−C) · D} · (Vs−V0) + V0 (Equation 2) C is the rate at which infrared rays from the food 2 pass through the lens of the infrared temperature sensor 4 and reach the hot junction. And infrared temperature sensor 4
Is a unique constant of (1-C) is an infrared temperature sensor 4
Is the rate at which it does not reach the hot junction and is absorbed by the lens or the like. D
Is a numerical value indicating an unbalanced state in which infrared energy that does not reach the hot junction of the infrared temperature sensor 4 occurs as a temperature change, and can be approximated by the following equation as a function of time.

D = 1−exp ｛− (t−t0 / τ｝ (Equation 3) τ is a response time constant of a temperature change and is a unique constant.
If t0) is fixed as a unit time, D is a unique constant. Vs is an ideal output voltage, which is also a convergence voltage of a response, and V0 is an output voltage before a temperature change.

FIG. 2 is a flowchart showing the flow of the heating control according to this embodiment. If V can be detected from the AD converter 8 (Step S1) and V-V0 per unit time can be detected as ΔV from the differentiator 9 (Step S2), the convergence voltage Vs can be calculated by the following equation from Equation 2.

Vs = (V−ΔV) + ΔV / {C + (1−C) · D} (Equation 4) The food initial temperature calculator 10 causes a rapid change in the temperature of the object to be measured when a unit time has elapsed from t0. That is, it is detected that the frozen food 2 or the like has been inserted (step S3),
V obtained from the AD converter 8 and Δ obtained from the differentiator 9
Vs and Vs are immediately obtained from Equations 4 by using predetermined constants C and D.
Is calculated (step S4), and this Vs is converted into an output voltage corresponding to the temperature difference between the food 2 and the infrared temperature sensor 4 to the temperature difference T01 (step S5). This conversion can be generally performed by a linear expression of a linear approximation, but may be approximated by a higher-order expression to improve the accuracy. Further, the temperature T0 of the infrared temperature sensor 4 obtained from the sensor temperature detection circuit 6
2 is detected (step S6), and the result is added to calculate the initial temperature T0 of the food 2 (step S7). Here, it is detected that the food 2 has been put in due to a sudden change in the temperature of the object to be measured, but even if it is detected that the food has been put in due to a sudden change in the weight. Often (step S8), in this case, ΔV per unit time before and after the change in weight may be used. The cooking time ts is calculated according to the flow of the above operation (step S9), and the cooking is started.

In this embodiment, the temperature of the food 2 is detected by the infrared temperature sensor 4 only at the initial stage of the uniform temperature distribution state without being influenced by the heating distribution.
There is an effect that cooking can be completed with high accuracy without depending on the visual field or the like.

(Embodiment 2) Next, a second embodiment of the present invention will be described with reference to FIGS. Note that the same components as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted. In FIG. 3, a timer 16 counts the time elapsed since the food 2 was put into the cooking chamber 1 and receives the output of the differentiator 9 if the absolute value of the output ΔV of the differentiator 9 is equal to or more than a predetermined value. to start. Other possible methods for activating the timer 16 include a method when the door (not shown) of the cooking chamber 1 is opened and a case where the food 2 is vibrated. The food temperature calculator 17 includes a sensor temperature detection circuit 6,
The output of the AD converter 8, the differentiator 9, and the timer 16 is received, and the temperature T of the food 2 is calculated every moment. The heating controller 15 receives the temperature T of the food 2 from the food temperature calculator 17 and drives the magnetron as the heating means 3 until the temperature reaches a predetermined set temperature Ts to complete the cooking.

FIG. 4 is a flowchart showing the flow of the heating control according to this embodiment. As shown in FIG. 4, when the food is first placed (step S11), the convergence voltage Vs is immediately calculated in the same manner as in the above-described embodiment (step S12).
At the same time, the initial temperature T0 of the food is calculated (step S1).
3). If not cooked, the voltage V obtained from the AD converter 8 gradually decreases as shown by the solid line b in FIG. 5 and approaches the convergence voltage Vs. However, in practice, when cooking is started by the user's operation at time t1 shown in FIG. 5, the temperature of the food 2 rises, and as shown by the broken line c, the voltage approaching Vs and the voltage increasing due to the temperature rise Increases or decreases slightly depending on the difference in However, solid line b and broken line c
Is caused by the temperature rise ΔT of the food. Therefore, the elapsed time (t-t0) after the food is put in is input from the timer 16, and the voltage Vb of the solid line b assumed when the food is not cooked is calculated by the equations 2 and 3 (step S14), and AD The voltage V is detected from the converter 8 (step S15), and the difference (V-Vb) from the voltage V is calculated. This (V−Vb) is the voltage difference between the dashed line c and the solid line b shown in FIG. 5 and is caused by the temperature rise ΔT of the food 2. Here, (V−Vb) is converted into ΔT (step S16), the above-mentioned initial temperature T0 of the food 2 is added to ΔT (step S17), and the result is output to the heating controller 15 as the current temperature T of the food 2. Is what you do.

In the case of the present embodiment, there is no need to detect the weight of the food 2, so that cooking equipment can be provided at a low price, and the effect of completing cooking accurately without being affected by the weight of the container in which the food 2 is placed. There is. Further, a neural network model comprising a plurality of neural elements is modeled in the food temperature calculator 17 and a plurality of fixed connection weighting coefficients for estimating the temperature of the food obtained by learning are contained therein. Can also be configured. In this case, you actually cook,
The output of the sensor temperature detection circuit 6, the AD converter 8, the differentiator 9, and the timer 16 and the food 2 every moment during the cooking.
Of the food 2 during cooking by learning the temperature of the food 2 and determining the binding weight coefficient in advance.
Is estimated, but the same effect as described above can be obtained.

In this embodiment, the description has been given of the case where the frozen food is heated as the rapid temperature change. However, the present invention can be similarly applied to the case of a relatively small temperature change such as in alcoholic beverages and milk. Although a magnetron is used as the heating means 3, the same effect can be obtained by another means such as a heater.

[0021]

As is apparent from the above description, according to the present invention, when food is put in the cooking chamber, the infrared temperature sensor outputs a voltage according to the food temperature, and the differentiator detects a temperature change. Then, the sensor temperature detector detects the temperature of the cold junction of the infrared temperature sensor, and the food initial temperature calculator calculates the convergence voltage of the output of the infrared temperature sensor from the output of the infrared temperature sensor and the output of the differentiator. The initial temperature of the food is calculated from the output of the temperature detector, and the heating controller controls the heating means based on the initial temperature of the food. Even if the output cannot follow due to a rapid change in temperature, automatic cooking that accurately detects the food initial temperature, cooks for an appropriate time, and achieves an appropriate finish is possible.

The infrared temperature sensor outputs a voltage according to the food temperature, the differentiator detects a temperature change, the sensor temperature detector detects the temperature of the cold junction of the infrared temperature sensor,
The food temperature calculator calculates the convergence voltage of the output of the infrared temperature sensor from the output of the infrared temperature sensor and the output of the differentiator, calculates the initial temperature of the food from the output of the sensor temperature detector, and further calculates the food temperature calculator. The temperature of the food is calculated every moment based on the output of the timer and the infrared temperature sensor and the initial temperature of the food, and the heating controller controls the heating means based on the calculation result, so the output of the infrared temperature sensor cannot be followed. Even when cooking is performed in a state where a delay is occurring, automatic cooking that completes cooking in an appropriately finished state by accurately detecting the temperature of food can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a cooking utensil according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a flow of the heating control.

FIG. 3 is a block diagram of a cooking utensil according to a second embodiment of the present invention.

FIG. 4 is a flowchart showing a flow of the heating control.

FIG. 5 is an output characteristic diagram of the infrared temperature sensor.

FIG. 6 is a block diagram of a conventional cooking utensil.

FIG. 7 is an output characteristic diagram of an infrared temperature sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cooking room 2 Food 3 Heating means 4 Infrared temperature sensor 5 Sensor temperature detector 9 Differentiator 10 Food initial temperature calculator 15 Heating controller 16 Timer

Continued on the front page (72) Inventor Masahiro Nitta 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 56) References JP-A-57-82995 (JP, A) JP-A-62-147227 (JP, A) JP-A-60-37708 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24C 7/02 330 F24C 7/02 320 G05D 23/19 G05D 23/27

Claims (3)

(57) [Claims] 1. A cooking chamber for storing food, heating means for heating the food in the cooking chamber, an infrared temperature sensor for generating a voltage according to the temperature of the food in the cooking chamber, and a temperature generated by the infrared temperature sensor A differentiator that detects a change in voltage to be applied, a sensor temperature detector that detects the temperature of the infrared temperature sensor, and a convergence voltage of the output voltage is estimated from an output voltage of the infrared temperature sensor and an output of the differentiator.
A food initial temperature calculator for calculating the food initial temperature from the estimated convergence voltage and the output of the sensor temperature detector; and a heating controller for controlling the heating means with the output of the food initial temperature calculator. Cookware. 2. The cooking appliance according to claim 1, further comprising a weight sensor for detecting the weight of the food, wherein the heating controller controls the heating means based on the output of the food initial temperature calculator and the output of the weight sensor. 3. A cooking chamber for storing food, a timer that starts when food is stored in the cooking chamber, heating means for heating the food in the cooking chamber, and a voltage according to the temperature of the food in the cooking chamber. An infrared temperature sensor, a differentiator for detecting a change in voltage generated from the infrared temperature sensor, a sensor temperature detector for detecting a temperature of the infrared temperature sensor, an output voltage of the infrared temperature sensor, and the differentiator. Estimate the convergence voltage of the output voltage from the output of
A food temperature calculator for calculating the food temperature from the estimated convergence voltage , the output of the sensor temperature detector, and the output of the timer, and a heating controller for controlling the heating means with the output of the food temperature calculator. Cookware.