JP2001165443A - Heat-cooking apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately control heating of foodstuffs even in the case where a surface temperature detecting means detects a surface temperature of a container containing an object to be heated. SOLUTION: When a surface temperature K reaches 45 deg.C after heating is started (yes at S3), the operation of a magnetron is brought into standstill to stop heating (S4). Then a controlling circuit calculates a period of time when the surface temperature K begins to lower, and stores it as a delay time Tdelay (S5-S11). In the case where the delay time Tdelay is ten seconds or longer, a cooking finishing temperature Kend is corrected on the basis of the delay time Tdelay (S12, S13). Thereafter, heating is resumed, and when the surface temperature reaches the cooking finishing temperature Kend, the heating is finished (S14-S16).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooking device for controlling heating by detecting the surface temperature of an object to be heated.

[0002]

Conventionally, a microwave oven is provided with a surface temperature detecting means for detecting a surface temperature of an object to be heated in a heating chamber, for example, an infrared sensor, and the temperature detected by the infrared sensor is a predetermined value. Are provided so as to end the heating when the temperature is reached. However, the infrared sensor detects the surface temperature of the measurement target in a non-contact manner. Therefore, if the object to be heated is a food contained in a container, for example, if the food is not exposed, such as sake in a bottle, the infrared sensor may directly detect the temperature of the food. No, the surface temperature of the container will be detected.

When the object to be heated is irradiated with microwaves, the susceptibility to heating differs due to the difference in dielectric constant due to the difference in water content. Therefore, when the object to be heated is composed of a food and a container, the food is heated before the container, and the container is warmed mainly by heat conduction from the food. Therefore, the temperature of the container tends to be lower than the temperature of the food.

Accordingly, as described above, if the heating is controlled based on the detected temperature when the infrared sensor detects the surface temperature of the container, the temperature of the food at the end of the heating increases. There was a defect.

The present invention has been made in view of the above circumstances, and has as its object to heat food even when the surface temperature detecting means detects the surface temperature of the container among the objects to be heated. An object of the present invention is to provide a heating cooker that can be controlled with high accuracy.

[0006]

According to a first aspect of the present invention, there is provided a heating cooker comprising: a heating chamber in which an object to be heated is accommodated; heating means for heating the object to be heated; A non-contact type surface temperature detecting means for detecting a surface temperature; and a control means for controlling heating by the heating means, wherein the control means determines an output of the heating means during heating of the object to be heated. It is characterized in that the heating is stopped by lowering or stopping the heating for a time and the heating by the heating means after the heating suspension period is controlled based on the detection result of the surface temperature detecting means during the heating suspension period.

According to the above invention, a heating pause period is provided during heating, and the surface temperature of the object to be heated is detected during the heating pause period. Can be determined as a container or a food. Then, since the subsequent heating is controlled based on the detection result of the surface temperature detecting unit during the heating suspension period, even when the surface temperature detecting unit detects the surface temperature of the container, Can be accurately controlled, and the food can be heated without excess or shortage.

In this case, the control means may control the heating after the heating suspension period based on the detection result of the surface temperature detection means during the heating suspension period and the detection result of the surface temperature detection unit before the heating suspension period. Cooking may be controlled (the invention of claim 2). According to the above configuration, the heating is controlled based on both the detection result by the surface temperature detection unit during the heating suspension period and the detection result by the surface temperature detection unit before the heating suspension period, so that the heating control accuracy is improved. .

When the object to be heated is composed of only food or a food and a container containing the food, the control means controls the temperature of the heated object detected by the surface temperature detecting means during the heating suspension period. Based on at least one of the change in the surface temperature of the object and the time from when the heating pause period is started until the surface temperature starts to decrease, the correlation between the detected value of the surface temperature detecting means and the temperature of the food is estimated. It is preferable to control the heating after the heating suspension period based on the estimated correlation (the invention of claim 3).

[0010] Further, the control means may include: a change in the surface temperature of the object to be heated detected by the surface temperature detecting means before the heating pause period; It is also a good configuration to estimate the correlation between the detected value of the surface temperature detecting means and the temperature of the food based on the temperature change of the object, and to control the heating and cooking based on the estimated correlation. 4 invention).

Further, a determination is made as to whether or not the surface temperature detecting means has detected the surface temperature of the food, based on a change in the surface temperature of the object to be heated detected by the surface temperature detecting means during the heating suspension period. It is a good configuration to include means (the invention of claim 5). In this case, when the rate of change per unit time of the surface temperature of the object to be heated detected by the surface temperature detecting means during the heating suspension period is less than the discrimination value, the surface temperature detecting means determines whether the surface temperature of the food is lower. It can be configured to determine that the temperature is detected (the invention of claim 6).

Further, it is preferable that the control means suspends the heating based on the fact that the temperature of the object to be heated detected by the surface temperature detecting means has reached a predetermined value (the invention of claim 7).
Further, the control means may suspend the heating when a predetermined time has elapsed from the start of the heating by the heating means.
Invention).

The apparatus further includes background temperature detecting means for detecting the background temperature of the object to be heated, wherein the control means detects the temperature of the object to be heated detected by the surface temperature detecting means by the background temperature detecting means. It is preferable to stop heating when a predetermined time has elapsed after the temperature has become higher than the background temperature (the invention of claim 9).

For example, depending on the cooking menu, there are cases where it is clear that the surface temperature detecting means is detecting the surface temperature of food, and cases where it is clear that the surface temperature of the container is being detected. Therefore, in the case where the menu setting means for setting the cooking menu is provided, the control means may execute the heating suspension operation according to the set cooking menu (the invention of claim 10).

Preferably, the surface temperature detecting means is capable of detecting the surface temperatures of a plurality of portions of the object to be heated (the invention of claim 11). According to the above configuration, since the surface temperature of the object to be heated can be detected over a wide range, the surface temperature varies depending on the portion of the object to be heated, for example, because the object to be heated is composed of a plurality of food materials. Even when there is, the average surface temperature of the whole object to be heated can be detected.

In this case, the control means controls the heating means based on the maximum value of the surface temperatures of a plurality of portions of the object to be heated detected by the surface temperature detection means (the invention of claim 12). The heating means may be controlled based on the detected values of the surface temperatures of a plurality of portions of the object to be heated detected by the surface temperature detecting means from a highest value to a predetermined order. .

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment in which the present invention is applied to a microwave oven (claims 1, 3, 5, 7, 10, 1) will be described.
1 and 13) will be described with reference to FIGS. First, in FIG. 3, a heating chamber 2 having an open front surface is provided inside a cabinet 1. A door 3 for opening and closing a front opening of the heating chamber 2 is rotatably mounted on the front surface of the cabinet 1. At the bottom of the heating chamber 2, a rotating net 4 made of an iron plate is provided.
The rotating net 4 is configured to be rotated by an RT motor 5 (shown only in FIG. 2) disposed below the bottom of the heating chamber 2. During cooking, a rotating plate (not shown) made of heat-resistant glass is set on the upper surface of the rotating net 4.

On the other hand, an operation panel 6 is provided at the right end of the front surface of the cabinet 1 in FIG. The operation panel 6 includes an operation unit 7 including various switches such as a start switch 7a and a plurality of cooking menu switches 7b serving as a cooking menu setting unit for setting various cooking menus. A display unit 8 for displaying time and the like.

The cooking menu includes menus suitable for warm cooking such as rice and side dishes (hereinafter referred to as "warm").
), Sake sake (hereinafter referred to as “sakekan”), milk,
Menu suitable for warm cooking such as coffee (hereafter,
Menu for warming cold fries etc. (hereinafter referred to as “Cool and Gourmet”)
And so on). Therefore, a desired cooking menu can be set by selecting and operating a corresponding switch from the plurality of cooking menu switches 7b.

As shown in FIG. 4, a machine room 9 is provided in the cabinet 1 behind the operation panel 6. In the machine room 9, various electric components such as a magnetron 10 serving as a heating means and a cooling fan 12 for cooling the magnetron 10 are provided. Further, an excitation port 13 is formed in the left side plate (right side plate of the heating chamber) 9 a of the machine room 9, and a waveguide 14 is formed in the left side plate 9 a of the machine room 9 so as to communicate with the excitation port 13. Is welded at one end. The magnetron 10 is screwed to the other end of the waveguide 14. With the above configuration, the microwave generated from the magnetron 10
The light is radiated from the excitation port 13 into the heating chamber 2 through the waveguide 14. As a result, the object to be heated (not shown) placed on the rotating dish is microwave-heated.

Further, a surface temperature detecting means 15 is provided above the machine room 9. The surface temperature detecting means 15 is configured to detect a surface temperature of an object to be heated in the heating chamber 2 through an opening formed in the left side plate 9a of the machine room 9. The surface temperature detecting means 15
Is, for example, a two-dimensional infrared solid-state imaging device (charge-coupled device, hereinafter, capable of detecting the surface temperature in a non-contact manner independently for each of a large number of finely divided fields of view,
"Infrared CCD 15"). In this embodiment, the detection field of view (temperature measurement area) of the infrared CCD 15 is configured to cover the rotating net 4 (that is, the rotating dish) and the bottom of the heating chamber 2 with, for example, 8 * 64 = 64 pixels. ing.

FIG. 2 is a diagram showing an electric configuration of the microwave oven according to the present embodiment by combining functional blocks.
In FIG. 4, a control circuit 16 as a control means is composed of a circuit mainly composed of a microcomputer. The control circuit 16 includes a timer 17 and the infrared C
The CD 15 and signals from various switches 7a and 7b of the operation unit 7 are configured to be input. Further, the control circuit 16 controls the cooling fan 1 via a drive circuit 18.
2. The configuration is such that the magnetron 10, the RT motor 5, and the display unit 8 are energized.

At this time, the control circuit 16 controls the energization of the cooling fan 12, the magnetron 10, and the RT motor 5 based on the built-in control program and the input signal, thereby executing the heating cooking. It is configured. That is, when the start of heating and cooking is instructed, the control circuit 16 sets the RT so that the rotating plate rotates at a constant speed.
The motor 5 is driven and the magnetron is driven at a predetermined output. Then, when the surface temperature of the object to be heated reaches a cooking end temperature set in advance according to the cooking menu, the heating cooking is finished.

At this time, the control circuit 16 is configured to calculate the surface temperature of the object to be heated as follows. That is, the infrared CCD 15 always detects the heat energy radiated from the object to be heated in the heating chamber 2, the rotating dish, and the bottom of the heating chamber 2 through the opening in a non-contact manner to correspond to each pixel. After being converted to the surface temperature, it is transmitted to the control circuit 16. The control circuit 16 increases the 64 surface temperatures ki after a predetermined time has elapsed since the start of heating (ki, i = 1 to 6).
Arrange in 4). Then, the average value of the temperatures from the highest value of the 64 temperatures k to a predetermined order, for example, the fifth temperature is set as the surface temperature K of the object to be heated.

This is because, when microwaves are irradiated for a predetermined time, foods having a large dielectric constant are intensively heated. This is because the temperature rise of the rotating plate and the bottom of the heating chamber 2 is small. Therefore, the surface temperature of the object to be heated is calculated based on the values from the highest value to the predetermined order in order to exclude the surface temperature of the object other than the object to be heated among the detection values of the infrared CCD 15. The detection accuracy of the surface temperature can be improved. Therefore, in this embodiment, the infrared CCD 15 and the control circuit 16
Constitutes a surface temperature detecting means.

The control circuit 16 determines that the surface temperature K of the object to be heated is, for example, 45.degree.
, The driving of the magnetron 10 is stopped to stop heating. In the present embodiment, the control circuit 16 suspends the heating in accordance with the set cooking menu, specifically, when “milk hot” and “sakekan” are set among various cooking menus. It is configured to be.

Further, the control circuit 16 controls the infrared CCD 15 based on the detection result of the infrared CCD 15 during the heating suspension period.
It is configured to control the subsequent heating. Specifically, the cooking end temperature Ken set in advance according to the time from when the heating is stopped to when the temperature of the object to be heated starts to decrease (hereinafter, referred to as a delay time Tdelay).
It is configured to correct d.

Here, the purpose of correcting the cooking end temperature Kend in accordance with the delay time Tdelay will be described with reference to FIGS.

In microwave heating, since the dielectric constant increases as the water content increases, the heating tends to be easy. Therefore, for example, in the case of cooking “Sakekan” in which sake is put into sake bottle, as shown in FIG. 5, the sake is first heated from the sake as a food, and the sake bottle as the container is mainly made from the sake. It will be heated by heat conduction.

Therefore, when the microwave heating is started, as shown in FIG. 6, the temperature of the food (liquor) rises immediately after the start of the heating, but the surface temperature of the container (the sake bottle) rises later from the start of the heating. In addition, when microwave heating is interrupted, the food starts to decrease in temperature relatively soon after the interruption of heating because the energy supply is lost, but the container keeps rising for a while after the interruption of heating due to heat conduction from the food. After a while, the temperature starts to drop. That is, there is a time lag between the temperature change of the container and the temperature change of the food. The delay time Tdelay correlates with such a time lag.

Further, as shown in FIG.
The infrared CCD 15 depends on the positional relationship between
There are a case where only the food is contained in the detection visual field (A), a case where only the container is contained (B), and a case where the food and the container are contained (C). Among them, in the case of B and C,
The detection result of the infrared CCD 15 differs from the actual food temperature. Even in the case of C, the difference from the actual food temperature differs depending on the proportion of the container in the detection visual field. And the length of the delay time Tdelay is
This is considered to correspond to the proportion of the container in the detection visual field.

Therefore, in this embodiment, the control circuit 1
6, when the value of the delay time Tdelay is smaller than a predetermined value, it is determined that the surface temperature of the food is detected;
If the value is equal to or more than a predetermined value, it is configured to determine that a container is interposed. Therefore, in the present embodiment, the control circuit 16 also functions as a determination unit. Then, when it is determined that a container is interposed, correction is made to lower the preset cooking end temperature in accordance with the delay time Tdelay.

Next, the operation of the above configuration will be described with reference to the flowchart of FIG. First, the user places the object to be heated on the rotating dish, and then sets the cooking menu switch 7.
By operating b, a desired heating menu is set. At this time, if either "warm milk" or "sake can" is set and the start switch 7a is operated, the flowchart of FIG. 1 starts.

That is, in step S1, the magnetron 1
0, the RT motor 5 and the cooling fan 12 are driven to start heating. In step S2, the surface temperature K of the object to be heated is detected. The surface temperature K is, as described above, the infrared C
This is the average of the values from the highest value to the fifth of the detected values of CD15.

Subsequently, in step S3, it is determined whether or not the surface temperature K has reached 45.degree.
Is reached (YES in step S3), driving of the magnetron 10 is stopped to stop heating (step S4).

When the heating is stopped, the control circuit 16 calculates the time until the surface temperature K of the object to be heated starts to decrease. That is, in step S5, the elapsed time t since the start of the heating suspension is set to 0, and in step S6, the surface temperature K (t) of the object to be heated is detected. Next, in step S7, it is determined whether or not the elapsed time t has reached the predetermined time a, and if not (NO), the process proceeds to step S8. In step S18, the surface temperature K (t + Δt) is detected,
In the next step S9, the magnitude relationship between the surface temperature K (t + Δt) and the surface temperature K (t) is compared. If the surface temperature K (t + Δt) is higher than the surface temperature K (t) (NO in step S9), the process proceeds to step S10 to update the elapsed time t and the surface temperature K (t). And
It returns to step S7.

On the other hand, in step S9, the surface temperature K (t
If (+ Δt) is lower than the surface temperature K (t) (YES in step S9), the process proceeds to step S11, and the time (t + Δt) at that time is set to the delay time Tdela.
Store as y. If the surface temperature K does not decrease even if the predetermined time a has elapsed from the start of the heating suspension operation (YES in step S7), the predetermined time a is set to the delay time T.
It is stored as delay.

Subsequently, in step S12, the delay time T
It is determined whether the delay is 10 seconds or more. Here, it is determined whether or not the infrared CCD 15 detects the surface temperature K of the food, based on the magnitude of the delay time Tdelay. That is, the delay time Tdelay is 10
If the time is shorter than the second, the temperature drops almost immediately after the heating is stopped. Therefore, the infrared CCD 15 determines that the surface temperature of only the food is detected, and the step S14 is performed without correcting the cooking end temperature. Move to.

On the other hand, if the delay time Tdelay is 10 seconds or more, there is a time lag from the stop of the heating to the temperature drop, so it is determined that the container is in the detection field of the infrared CCD 15 and the step is taken. The process proceeds to S13 to correct the cooking end temperature Kend. Specifically, the correction value Kd
Where Kd = c1 * (Tdelay-10) (c1 is a constant), the cooking end temperature Kend is reduced by the correction value Kd.

Subsequently, in step S14, the magnetron 10 is driven to restart heating. After this, step S
In step S16, it is determined whether or not the surface temperature K has reached a preset or corrected cooking end temperature Kend. Then, when the surface temperature K reaches the cooking end temperature Kend (step S16)
YES), the driving of the magnetron 10, the RT motor 5, and the cooling fan 12 is stopped to end the heating and cooking.

According to the present embodiment having such a configuration, the heating pause period is provided during heating, and the delay time Tdela is determined from the detection result of the infrared CCD 15 during the heating pause period.
y is calculated, and it is determined whether or not the infrared CCD 15 detects the surface temperature of only the food, in other words, whether or not the container is in the detection visual field of the infrared CCD 15 based on the magnitude of the delay time Tdelay. It was configured as follows. Then, when it is determined that the container is in the detection visual field of the infrared CCD 15, the correction value Kd is calculated based on the delay time Tdelay, and the preset cooking end temperature Kend is corrected to be lower. .

Therefore, even if a container is in the detection field of view of the infrared CCD 15, the heating can be controlled on the basis of the cooking end temperature in consideration of the container.
The food can be prevented from being excessively heated. In particular, in the present embodiment, the cooking end temperature is corrected in accordance with the size of the delay time Tdelay, that is, in accordance with the proportion of containers in the detection field of view of the infrared CCD 15, so that the accuracy is further improved. Heating can be controlled.

Further, in the present embodiment, the heating suspension period is provided in accordance with the set menu. In other words, when food is placed directly on a rotating plate and cooked, as in the “Cool and Gourmet” menu, in which cold fries and the like are heated in a crisp state, heating is not interrupted halfway. did. Therefore, when a menu clearly indicating that the surface temperature of the food is detected is being executed, the problem of determining whether or not the detection target of the infrared CCD 15 is a food is eliminated, and the control suitable for the setting menu is eliminated. It can be performed.

Further, in this embodiment, the infrared CCD 15
The surface temperature of the object to be heated is calculated based on the values from the highest value to the predetermined order among the detected values of. In other words, since the detection values of the objects other than the object in the detection field of view of the infrared CCD 15 are excluded, the surface temperature of the object to be heated can be accurately detected.

FIG. 8 shows a second embodiment of the present invention.
And 3), and different points from the first embodiment will be described. The same parts as those of the first embodiment are denoted by the same reference numerals. That is, as described in the first embodiment, when either "warm milk" or "shukan" is set and the start switch 7a is operated,
Heat cooking is started according to the flowchart of FIG. 8 (step R1). At this time, when the surface temperature K of the object to be heated reaches 45 ° C. (Y in steps R2 and R3).
ES), and in the next step R4, the temperature rise rate α is calculated and stored. The temperature rise rate α is represented by the following equation, where K0 is the surface temperature at the start of heating, and T is the time from when heating and cooking is started until the surface temperature K reaches 45 ° C. α = (45−K0) / T Subsequently, in step R5, the driving of the magnetron 10 is stopped, and the heating is stopped. Steps R5 to R12 are the same as steps S4 to S11 in the flowchart shown in the first embodiment, and calculate the delay time Tdelay. Next step R1
In 3, it is determined whether or not the delay time Tdelay is 10 seconds or more, and if it is 10 seconds or more (YE at R13).
In step S14, in step R14, the cooking end temperature Kend
Is corrected.

Specifically, the correction value Kd is calculated as follows: Kd = c1 * (Tdelay-10) + c2 * (1 /
α) (c1 and c2 are constants), the cooking end temperature Kend is reduced by the correction value Kd.

Here, the reason why the cooking end temperature Kend is corrected by the correction value calculated by using the delay time Tdelay and the temperature rise rate α as variables is as follows. That is,
When food is heated at a constant output, the temperature increases more slowly when the food load is larger than when the food load is small.
That is, when the load of the food is large, the temperature rise rate α decreases. In addition, when the load is large, it takes time to conduct heat inside the food. Therefore, the temperature difference between the food and the container tends to be smaller in the heated object including the food and the container having a large load. Further, when the load of the food is large, the heat source for heating the container is increased accordingly, so that the temperature of the container and the temperature of the food are easily approached.

Therefore, in the present embodiment, the temperature rise rate α having a correlation with the load is calculated, and this temperature rise rate α is added to the variable for correcting the cooking end temperature Kend. That is, in the second embodiment, since the cooking end temperature Kend is corrected based on both the delay time Tdelay and the temperature rise rate α, the heating can be controlled more accurately.

Since the configuration other than the above is the same as that of the first embodiment, the description is omitted. Therefore, in this embodiment, the same operation and effect as in the first embodiment can be obtained.

In the above embodiment, the load is estimated from the temperature rise rate α. However, a weight sensor for detecting the weight of the object to be heated placed on the rotating plate is provided. The cooking end temperature Kend may be corrected based on both the detected value and the delay time Tdelay. Further, the load of the food may be estimated from both the detected value of the weight sensor and the temperature rise rate α, and the cooking end temperature Kend may be corrected based on the estimated value and the delay time Tdelay.

FIGS. 9 and 10 show a third embodiment of the present invention. Differences from the second embodiment will be described.
The same parts as those of the second embodiment are denoted by the same reference numerals. That is, in the third embodiment, as shown in FIG.
Further, a temperature sensor 21 for detecting the temperature in the heating chamber 2 (inside the refrigerator) is provided, and a signal from the temperature sensor 21 is input to the control circuit 16.

As shown in the flowchart of FIG. 10, in this embodiment, when the heating and cooking are started and the surface temperature K of the object to be heated reaches 45 ° C. (step U1).
~ U3, YES at step U3), next step U4
Stores the temperature rise rate α and the internal temperature Kr.

Subsequently, in step U5, the driving of the magnetron 10 is stopped to stop heating. This step U
5 to step U12 are the same as steps R5 to R12 shown in the flowchart of FIG.
The delay is calculated. In the next step U13,
It is determined whether or not the delay time Tdelay is 10 seconds or more. If it is 10 seconds or more (YES in U13), the cooking end temperature Kend is corrected in step U14.

Specifically, the correction value Kd is calculated as follows: Kd = c1 * (Tdelay-10) + c2 * (1 /
α) + c3 * (c4-Kr) (c1, c2, c3, c4
Is a constant. However, when c4 ≧ Kr, c3 = 0. ), The cooking end temperature Kend is reduced by the correction value Kd.

Here, the correction value K of the cooking end temperature Kend
The reason why the internal temperature Kr is further added to the variable of the formula for calculating d is as follows. That is, when the temperature in the refrigerator is higher than the container temperature, the container is also warmed by the atmosphere in the refrigerator. Therefore, when the temperature in the refrigerator is higher, the temperature difference between the container and the food tends to be smaller.

Therefore, in this embodiment, the internal temperature K
r is added to a variable for correcting the cooking end temperature Kend. That is, in the third embodiment, the cooking end temperature Kend is corrected on the basis of the three variables of the delay time Tdelay, the temperature rise rate α, and the internal temperature Kr, so that the heating is more accurately controlled. can do.

Since the configuration other than the above is the same as that of the second embodiment, the description is omitted. Therefore, in this embodiment, the same operation and effect as those of the second embodiment can be obtained.

FIG. 11 shows a fourth embodiment (corresponding to claims 2 and 8) of the present invention, and the differences from the third embodiment will be described. The same parts as those of the first embodiment are denoted by the same reference numerals. That is, in the fourth embodiment, the control circuit 16 is configured to stop heating based on the fact that the elapsed time Tb from the start of heating has reached the predetermined time b (steps V1 to V5). At this time, the control circuit 16 stores the surface temperature Koff of the object to be heated at that time in addition to the temperature rise rate α and the internal temperature Kr (step V4).

When the heating is stopped in step V5, the delay time Tdela is set in the same manner as in steps U6 to U12 described above.
y is calculated (steps V6 to V12). Subsequently, in step V13, it is determined whether or not the delay time Tdelay is 10 seconds or longer, and if it is 10 seconds or longer (V13
In step V14, the cooking end temperature Kend is corrected.

Specifically, the correction value Kd is calculated as follows: Kd = c1 * (Tdelay-10) / Koff-c
5) + c2 * (1 / α) + c3 * (c4-Kr) (c
1, c2, c3, c4, and c5 are constants. However, c4 ≧ Kr
At the time of c3 = 0. When c5 ≧ Koff, c5
= 0), the cooking end temperature Kend is reduced by the correction value Kd.

Here, the correction value K of the cooking end temperature Kend
The variable of the formula for calculating d further includes the surface temperature Ko at the time of stopping heating.
The reason for adding ff is as follows. That is, it is considered that the larger the temperature of the object to be heated from the start of the heating to the stop of the heating, the larger the temperature difference between the food and the container. In many cases, the temperature of the food at the start of heating and the temperature of the container are almost the same. Therefore, in the present embodiment, the surface temperature Koff at the time of stopping heating is further added to the variable of the equation for calculating the correction value Kd. Therefore, the constant c5 in the above-described equation for calculating the correction value Kd means the temperature at the start of heating (initial temperature). Note that, here, the initial temperature is set to the constant c5, but the detection value of the infrared CCD 15 at the time of starting heating is stored.
It may be substituted as a variable.

According to the present embodiment having such a configuration, the cooking end temperature Kend is corrected based on the four variables of the delay time Tdelay, the temperature rise rate α, the inside temperature Kr, and the surface temperature Koff at the time of stopping heating. Because it was configured as
The heating can be controlled more accurately.

Since the configuration other than the above is almost the same as that of the third embodiment, the present embodiment can provide the same operation and effects as those of the third embodiment.

FIG. 12 shows a fifth embodiment (corresponding to claim 4) of the present invention, and different points from the second embodiment will be described. The same parts as those of the second embodiment are denoted by the same reference numerals. In the fifth embodiment, the temperature rise rate α before the heating suspension period and the temperature rise rate αoff during the heating suspension period
The characteristic is that the cooking end temperature is corrected based on the above. That is, as described in the second embodiment, when either “warm milk” or “sakekan” is set and the start switch 7a is operated, the heating cooking starts according to the flowchart of FIG. (Step W1). At this time, when the surface temperature K of the object to be heated reaches 45 ° C. (YES in step W2 and step W3),
In the next step W4, the temperature rise rate α is stored. Subsequently, in step W5, the driving of the magnetron 10 is stopped, and the heating is stopped.

When the predetermined time a elapses, the heating suspension period ends (YES in steps W6 and W7), and the temperature rise rate αoff is calculated and stored in the next step W8. This temperature rise rate αoff is expressed by the following equation, where K1 is the temperature at the end of the heating suspension period. α = (K1-45) / a Subsequently, in step W9, the cooking end temperature Kend is corrected. Here, the correction value Kd is given by: Kd = p1 * (αoff−α) + p2 * αoff + p3
When * α (p1, p2, and p3 are constants), the cooking end temperature Kend is reduced by the correction value Kd.

When microwave heating is performed, the food and the container are easily heated, so that the rate of temperature rise from the start of heating to the stop of heating is different. Further, when the heating is stopped, the temperature of the food starts to decrease immediately after the heating of the container is stopped after the heating is stopped. Therefore,
The temperature rise rate (actually the temperature decrease rate) during the heating suspension period differs between the food and the container. Therefore, in the present embodiment, the cooking end temperature Kend is set to the temperature rise rate α and αo.
The correction was performed using the correction value Kd calculated using ff as a variable.

Therefore, also in the present embodiment having the above configuration,
The heating of the object to be heated can be controlled with high precision, and even if the surface temperature of the container is detected by the infrared CCD 15, the food can be heated without excess or shortage. In the fifth embodiment, the cooking end temperature is always corrected. However, the correction may be performed only when the temperature increase rate αoff exceeds a predetermined determination value. That is, when the temperature rise rate αoff is equal to or less than the predetermined determination value, it is determined that the surface temperature of the food is detected,
Do not correct the cooking end temperature.

FIG. 13 shows a sixth embodiment (corresponding to claims 3 and 4) of the present invention. Differences from the fifth embodiment will be described. In the sixth embodiment, the temperature rise rate α before the heating suspension period, the temperature rise rate αo during the heating suspension period
ff, and the temperature change ΔKo during the heating pause period.
The feature is that the correction value Kd is calculated using ff as a variable.

That is, as shown in the flowchart of FIG. 13, the same processing as steps W1 to W7 shown in the flowchart of FIG. 12 is executed in steps W1 to X7. Then, at step X8, the temperature change ΔKoff is calculated and stored together with the temperature rise rate αoff. In the present embodiment, the temperature change ΔKoff is defined as follows.

ΔKoff = K1−45 Subsequently, in step X9, a correction is made to lower the cooking end temperature Kend by the correction value Kd. In this case, the correction value Kd is calculated from the following equation.

Kd = p1 * (αoff−α) + p2 * α
off + p3 * α + p4 * ΔKoff (p1, p2, p
(3, p4 is a constant) The correction value Kd is defined in consideration of the fact that when the heating is stopped, the temperature of the food immediately decreases, but the temperature of the container once increases and then decreases. That is, the larger the temperature change ΔKoff during the heating suspension period, the larger the infrared CCD 1
The ratio of food in the detection field of view 5 is large, and the temperature change Δ
The smaller the Koff, the larger the proportion of the container in the detection field of view of the infrared CCD 15.

Therefore, also in the present embodiment having the above configuration,
The heating of the object to be heated can be controlled with high precision, and even if the surface temperature of the container is detected by the infrared CCD 15, the food can be heated without excess or shortage.

FIG. 14 shows a seventh embodiment of the present invention, and the differences from the sixth embodiment will be described. In the seventh embodiment, in addition to the temperature rise rate α before the heating suspension period, the temperature rise rate αoff during the heating suspension period, and the temperature change ΔKoff during the heating suspension period, the temperature change rate during the heating suspension period is further reduced. The feature is that the correction value Kd is calculated using the pattern as a variable.

That is, as shown in the flowchart of FIG. 14, the same processing as steps X1 to X7 shown in the flowchart of FIG. 12 is executed in steps Y1 to Y7. Then, in step Y8, the temperature rise rate αoff,
The temperature change pattern variable r along with the temperature change ΔKoff
n is stored.

Subsequently, in step Y9, a correction is made to lower the cooking end temperature Kend by the correction value Kd.
In this case, the correction value Kd is calculated from the following equation. Kd = p1 * (αoff−α) + p2 * αoff + p3
* Α + p4 * ΔKoff + ff (rn) (p1, p2,
p3 and p4 are constants, and ff (rn) is a function for converting the temperature change pattern variable rn into a numerical value.) The temperature change pattern is, for example, a type in which the temperature starts to decrease immediately after the stop of heating, and the temperature once increases after the stop of heating. It is classified into various types, such as a type in which the temperature starts to decrease after that, and a type in which the temperature at the start of the thermal pause is lower than the temperature at the end of the thermal pause period. Then, a variable rn is set in advance for each pattern, and the correction value Kd is calculated based on the variable rn. Note that the variable rn and the function are obtained experimentally. Also in the present embodiment having such a configuration, the heating of the object to be heated can be accurately controlled.

The present invention is not limited to the embodiment described above and shown in the drawings. For example, the following modifications are possible. In each of the above embodiments, the magnetron 1
Although the configuration is such that the driving of the magnetron 10 is stopped by stopping the driving of the magnetron 10, the output of the magnetron 10 is controlled to be lower than that during the heating operation and the heating is stopped by performing inverter control. .

The highest value among the detection values of the infrared CCD 15 may be used as the surface temperature of the object to be heated. In addition to the infrared CCD, the surface temperature detecting means has a wide field of view.
The element may be constituted by a thermopile or pyroelectric infrared sensor. Further, it is also possible to use an eight-element infrared sensor arranged in a one-dimensional array and combine the data detected for one rotation of the rotating dish to make it two-dimensional.

Further, a background temperature detecting means for detecting the background temperature of the object to be heated, for example, the temperature of the rotating plate, is provided, and the heating is performed when a predetermined time elapses after the detected temperature of the surface temperature detecting means becomes higher than the background temperature. May be paused.
In this case, the background temperature is, for example, as follows:
It can be calculated from the detection result of D15.

That is, when irradiated with microwaves, a food having a large dielectric constant and a container that conducts heat directly from the food are:
While the temperature change is large, the rotating dish has a small temperature change. Therefore, the infrared CCD input to the control circuit 16
Of the fifteen detected values, the one with a small temperature change can be set as the background temperature. Therefore, in this case, the infrared CC
D15 and the control circuit 16 constitute a background temperature detecting means.

Further, the present invention can be applied not only to a microwave oven for performing only microwave heating but also to a microwave oven with a heater capable of oven cooking and grill cooking.

[0081]

As is apparent from the above description, according to the heating cooker of the present invention, the heating is stopped by lowering or stopping the output of the heating means for a predetermined time during the heating of the object to be heated. A pause period is provided, and the heating after the heating pause period is controlled based on the detection result of the surface temperature detecting means in the heating pause period, so that the heating of the object to be heated can be accurately controlled, Even if the temperature detected by the surface temperature detecting means is the surface temperature of the container, the food can be heated without excess or shortage.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention, and is a flowchart showing a processing procedure from the start to the end of heating cooking.

FIG. 2 is a block diagram showing an electrical configuration.

FIG. 3 is a front view showing a microwave oven by a perspective drawing method.

FIG. 4 is a cross-sectional plan view of a microwave oven.

FIG. 5 is a view for explaining how the temperature of the container rises due to heat conduction from food.

FIG. 6 is a diagram schematically showing the relationship between the heating time and the temperatures of the food and the container.

FIG. 7 is a diagram showing a relationship between a visual field of a surface temperature detecting unit and an object to be heated;

FIG. 8 is a view corresponding to FIG. 1, showing a second embodiment of the present invention.

FIG. 9 is a view corresponding to FIG. 4, showing a third embodiment of the present invention.

FIG. 10 is a diagram corresponding to FIG. 1;

FIG. 11 is a view corresponding to FIG. 9, showing a fourth embodiment of the present invention;

FIG. 12 is a view corresponding to FIG. 8, showing a fifth embodiment of the present invention;

FIG. 13 is a view corresponding to FIG. 12, showing a sixth embodiment of the present invention;

FIG. 14 is a view corresponding to FIG. 13 showing a seventh embodiment of the present invention.

[Explanation of symbols]

In the figure, 2 is a heating chamber, 7b is a menu setting means, 10 is a magnetron (heating means), 15 is an infrared CCD (surface temperature detecting means), and 16 is a control circuit (control means, surface temperature detecting means, discriminating means). Show.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshio Kakizawa 991 Anata-cho, Seto-shi, Aichi Prefecture Inside the Toshiba Aichi Factory (72) Inventor Minamitsu 991 Anata-cho, Seto-shi, Aichi Toshiba A.V.・ E-term Nagoya Office F-term (reference) 3L086 AA04 CA11 CA12 CA16 CB10 CB14 CB16 CC03 CC08 CC11 CC12 DA20 3L087 AA04 BA06 BA09 BB07 BB12 BC03 BC07 BC10 BC11 DA20

Claims (13)

[Claims] 1. A heating chamber in which an object to be heated is accommodated, heating means for heating the object to be heated, non-contact type surface temperature detecting means for detecting a surface temperature of the object to be heated, A heating cooker provided with control means for controlling heating by the heating means, wherein the control means lowers or stops the output of the heating means for a predetermined time during heating of the object to be heated, and suspends the heating. A heating cooker that controls heating by the heating unit after the heating suspension period based on a detection result of the surface temperature detection unit during the heating suspension period. 2. The heating control device according to claim 1, wherein the control unit performs heating cooking after the heating suspension period based on a detection result of the surface temperature detection unit during the heating suspension period and a detection result of the surface temperature detection unit before the heating suspension period. The heating cooker according to claim 1, wherein the heating cooker is controlled. 3. The object to be heated is composed of only food, or a food and a container containing the food, and the control means controls the surface temperature of the object to be heated detected by the surface temperature detection means during the heating suspension period. Estimating the correlation between the detected value of the surface temperature detection means and the temperature of the food, based on at least one of the time from the start of the change and the heating pause period to the start of the decrease in the surface temperature, the estimated correlation The heating cooker according to claim 1, wherein heating after the heating suspension period is controlled based on the relationship. 4. The object to be heated is composed of only food or a food and a container containing the food, and the control means controls the surface of the object to be heated detected by the surface temperature detecting means before the heating suspension period. Estimating the correlation between the detected value of the surface temperature detecting means and the temperature of the food, based on the temperature change and the change in the surface temperature of the object to be heated detected by the surface temperature detecting means during the heating suspension period. The heating cooker according to claim 1, wherein heating after the heating suspension period is controlled based on the estimated correlation. 5. The object to be heated is composed of food alone or a food and a container containing the food, and based on a change in the surface temperature of the object to be heated detected by the surface temperature detecting means during the heating suspension period. 5. The apparatus according to claim 1, further comprising a determination unit configured to determine whether the surface temperature detection unit detects the surface temperature of the food.
A heating cooker according to any one of the above. 6. When the rate of change of the surface temperature of the object to be heated per unit time detected by the surface temperature detecting means during the heating suspension period is less than the discrimination value, the surface temperature detecting means determines that the food temperature The cooking device according to claim 5, wherein it is determined that the surface temperature is detected. 7. The heating cooker according to claim 1, wherein the control unit suspends the heating based on a value detected by the surface temperature detecting unit reaching a predetermined value. 8. The cooking device according to claim 1, wherein the control unit suspends the heating when a predetermined time has elapsed from the start of the heating by the heating unit. 9. A background temperature detecting means for detecting a background temperature of the object to be heated, wherein the control means detects a surface temperature of the object to be heated detected by the surface temperature detecting means by the background temperature detecting means. The heating cooker according to any one of claims 1 to 6, wherein heating is stopped when a predetermined time has elapsed since the temperature became higher than the background temperature. 10. The heating cooking according to claim 1, further comprising menu setting means for setting a cooking menu, wherein the control means suspends heating according to the set cooking menu. vessel. 11. The cooking device according to claim 1, wherein the surface temperature detecting means is configured to detect surface temperatures of a plurality of portions of the object to be heated. 12. The heating unit according to claim 11, wherein the control unit controls the heating unit based on the maximum value of the surface temperatures of a plurality of portions of the object to be heated detected by the surface temperature detection unit. Cooking device. 13. The control means controls the heating means based on the detected values of the surface temperatures of a plurality of portions of the object to be heated detected by the surface temperature detecting means from the highest value to a predetermined order. The heating cooker according to claim 11, wherein