JP2002299029A - Induction cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain emissivity of a heated material at a low cost and to provide an induction cooker, capable of detecting stain on the light-receiving part of an infrared sensor and noticing the stain. SOLUTION: The induction cooker comprises the infrared sensor for detecting infrared rays radiated from a heated material, a heat sensitive element thermally in contact with the heated material, an estimating means for estimating the emissivity of the infrared rays radiated from the heated material, based on the quantity of infrared rays detected by the infrared sensor and the temperature detected by the heat sensitive element, and a radiation temperature calculating means for calculating the radiation temperature of the heated material, based on the emissivity of the heated material estimated by the estimating means and the quantity of infrared rays detected by the infrared ray sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating cooker having a function of detecting a temperature of an object to be heated.

[0002]

2. Description of the Related Art FIG.
It is a block diagram of a heating cooker using a conventional infrared sensor disclosed in Japanese Patent Publication No. 81. In the figure, reference numeral 1 denotes, for example, an electromagnetic induction heating cooker, 2 denotes a pan, 3 denotes an arithmetic control processing unit for performing overall control of the heating cooker 1 and calculation of temperature calculation, and 4 denotes an instruction from the arithmetic control processing unit 3. A heating control unit for controlling the heating of the pan 2, a light emitting element 5 for irradiating light to the bottom of the pan 2, a light receiving sensor 6 for receiving light reflected from the bottom of the pan 2, and a light emitting sensor 7 for the light emitting element 5. A light emission control unit for controlling light emission and extinguishing, 8 is a reflection detection unit for detecting the output of the light receiving sensor 6, 9 is an infrared sensor for detecting the amount of infrared light emitted from the bottom of the pan 2, and 10 is an infrared sensor. Is a top plate of the cooking device 1, which is partially or entirely made of a material that transmits infrared rays.

FIG. 12 shows the relationship between the reflectance and the emissivity for infrared rays of a certain wavelength, and 121 is a characteristic curve showing this relationship. It can be seen from the figure that the higher the reflectance R, the lower the emissivity e, and the lower the reflectance R, the higher the emissivity e.

[0004] FIG. 13 shows the amount of infrared light W received by the infrared sensor 9 using the emissivity e as a parameter, and the amount of the object to be heated calculated by the radiation detection unit 10 and the arithmetic and control unit 3 based on this. This shows the relationship with the converted temperature T.
In the figure, 131, 132 and 133 are emissivity e, respectively.
7 is a characteristic curve showing the relationship between the amount of infrared light W and the converted temperature T when the values are 1.0, 0.5, and 0.1. The lower the emissivity is, the smaller the rate of infrared radiation at the same temperature is. Therefore, when the same amount of infrared light W0 is detected as shown in the figure, the temperature of the object to be heated increases as the emissivity decreases. (T0 <T1 <T2).

Next, the operation will be described with reference to FIGS. In FIG. 11, first, the arithmetic control processing unit 3 instructs the light emission control unit 7 to turn on the light emitting element 5. Thereby, the light emitted from the light emitting element 5 irradiates the bottom of the pan 2,
The light reflected at the bottom is received by the light receiving sensor 6.
The output of the light receiving sensor 6 is converted into a voltage amount by the reflection detecting unit 8, and is input to the arithmetic and control processing unit 3, where the reflectance is calculated. Here, the arithmetic control processing unit 3 stores a calculation formula or a data table corresponding to the characteristic curve 121 indicating the relationship between the reflectance and the emissivity as shown in FIG.
The emissivity is calculated from the reflectance based on this calculation formula or data table.

On the other hand, infrared rays radiated from the bottom of the pan 2 are received by an infrared sensor 9, converted into a voltage amount by a radiation detection unit 10, and input to an arithmetic control processing unit 3.
In addition to the characteristic curve 121 described above, the arithmetic control processing unit 3
A calculation formula for converting the temperature from the relationship between the amount of infrared rays and the emissivity e as shown in FIG. 13 or a table of conversion data is stored. The temperature at the bottom of the pan 2 is calculated based on this formula or the conversion data table.

As described above, the conventional cooking device 1 using the infrared sensor 9 is configured to calculate the temperature of the object to be heated by calculating the emissivity e of the object to be heated. Can be detected without being affected by the reflectivity, and can be detected with almost no time delay with respect to a change in the temperature of the object to be heated.

[0008]

However, in such a configuration of the conventional heating cooker 1, in order to obtain the emissivity of the object to be heated, a light emitting element for irradiating light to the object to be heated, There is a problem that a light receiving element for receiving the reflected light from the object is required, and the cost is increased. In addition, if the optical paths of the infrared sensor 9, the light emitting element, and the light receiving element are contaminated and shielded from light, detection of infrared rays and reflectance radiated from the object to be heated becomes insufficient, and there is a problem that an accurate temperature cannot be detected. .

The present invention has been made to solve such a problem, and an object of the present invention is to provide an induction heating cooker which can obtain the emissivity of an object to be heated at low cost.
It is another object of the present invention to obtain an induction heating cooker that can detect dirt on the light receiving unit of the infrared sensor 9 and notify the user of the dirt.

[0010]

An induction heating cooker according to the present invention comprises an infrared sensor for detecting infrared rays emitted from an object to be heated, a thermosensitive element in thermal contact with the object to be heated, and an infrared sensor. Estimating means for estimating the emissivity of infrared light emitted from the object to be heated based on the detected amount of infrared light and the temperature detected by the thermosensitive element, and detecting the emissivity of the object to be heated estimated by the estimating means and the infrared sensor. And a radiation temperature calculating means for calculating a radiation temperature of the object to be heated from the obtained infrared ray amount.

In the estimating means for estimating the emissivity of the object to be heated, the fluctuation of the temperature detected by the thermosensitive element and the amount of the infrared ray detected by the infrared sensor continue within a predetermined range for a predetermined time or more. It is to be executed in the case.

In addition, when the temperature detected by the thermosensitive element exceeds a radiation temperature calculated from the amount of infrared rays detected by the infrared sensor and the emissivity of the object to be heated for a predetermined time or more, and then becomes equal to or more than a predetermined temperature difference. The temperature of the object to be heated thereafter is set as the temperature detected by the thermosensitive element.

In addition, when the temperature detected by the thermosensitive element exceeds the radiation temperature calculated from the amount of infrared rays detected by the infrared sensor and the emissivity of the object to be heated and continues for a predetermined time or more, and then exceeds a predetermined temperature difference. A state confirmation requesting means for requesting confirmation of a light incident state of the infrared sensor.

When the temperature detected by the heat-sensitive element fluctuates faster than the radiation temperature calculated from the amount of infrared rays detected by the infrared sensor and the emissivity of the object to be heated, the temperature of the object to be heated thereafter is changed to the heat-sensitive temperature. The temperature detected by the element is set.

Furthermore, the temperature detected by the thermosensitive element is
In the case where the radiation temperature changes faster than the radiation temperature calculated from the amount of infrared rays detected by the infrared sensor and the emissivity of the object to be heated, a state confirmation request means for requesting confirmation of the light incident state of the infrared sensor is provided. Things.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a block diagram of an induction heating cooker according to Embodiment 1 of the present invention. The same or similar parts as those in the conventional example are denoted by the same reference numerals, and description thereof is omitted. In the figure, 12 is the top plate 1
1, a heat-sensitive element such as a thermistor provided so as to be in thermal contact with the center of the back surface; 13, a heat-sensitive detector for detecting the output of the heat-sensitive element 12; An operation unit for performing operation inputs such as output adjustment and estimation of a pan temperature, a display unit 15 for displaying a heating / stop state, a pan temperature, and the like, and an infrared light amount detected by the infrared sensor 9 via the radiation detection unit 10 From the back surface temperature of the top plate 11 detected by the thermosensitive element 12 via the heat sensing unit 13 and the temperature of the pan 2 that is the object to be heated placed on the top plate 11,
A temperature detection controller 17 for controlling the entire induction heating cooker 1 is a heating coil.

FIG. 2 is a block diagram showing the configuration of the temperature detection control unit 16. As shown in FIG. In the figure, 16a is a CPU
A control unit 16b, control program data executed by the control unit 16a, a timer unit 16c for periodically outputting an interrupt signal to the control unit 16a, a timer counter 16d for counting time, and 16e a timer counter for counting time. This is a thermosensitive element detected temperature data storage unit that stores the current value, the maximum value, and the minimum value of the temperature data calculated from the thermal data acquired from the thermal sensor 13. Similarly, 16f is the radiation detecting unit 10
It is an infrared amount data storage unit for storing the current value, the maximum value, and the minimum value of the infrared amount data fetched from. 16
g and 16h are a heated object emissivity data storage unit and a radiation temperature data storage unit, respectively. 16i is a thermosensitive element temperature data table for storing the correspondence between thermosensitive data and temperature;
16j is an infrared amount / temperature data table for storing the correspondence between infrared amount data and temperature at each emissivity;
k is a detected temperature storage unit for storing the detected temperature of the object to be heated.

FIG. 3 is a flowchart of a detected temperature calculation process for calculating the temperature of the pan 2, and FIG. 4 is a diagram for estimating the emissivity of the object to be heated from the detected temperature of the thermosensitive element and the amount of infrared rays emitted from the object to be heated. FIG. 4 is an explanatory diagram for explaining a method of performing the operation.

Next, the operation will be described with reference to FIGS. In FIG. 1, an infrared sensor 9 is arranged to detect infrared rays emitted from the side surface of the pan 2. When a heating instruction is input from the operation unit 14, the temperature detection control unit 16 displays that the heating state has occurred on the display unit 15, and drives the heating coil 17 via the heating control unit 4. The current amount of the heating coil 17 is taken in as current data. In addition, the infrared ray amount is detected by the infrared sensor 9 via the radiation detecting unit 10, and the top plate 1 is detected from the heat-sensitive data detected by the heat-sensitive element 12 via the heat-sensitive detecting unit 13.
1. Detect the temperature of the back surface.

Further, the temperature detection control unit 16 performs a detected temperature calculation process for calculating the temperature of the pan 2 from the detected infrared ray amount and the back surface temperature of the top plate 11, and the temperature of the pan 2 is estimated by the operation unit 14. The heating instruction data is output to the heating control unit 4 so as to reach the temperature. These series of control operations are performed by the operation control unit 16, the display unit 15, and the heat-sensitive detection unit 13 based on the control program data 16 b by the arithmetic control unit 16 a of the temperature detection control unit 16 using an interrupt signal periodically generated from the timer unit 16 c. , The radiation detection unit 10 and the heating control unit 4 while appropriately exchanging data.

Here, the detected temperature calculation processing for calculating the temperature of the pan 2 will be described with reference to FIG. When a heating instruction is input from the operation unit 14 and heating is started, the arithmetic control unit 16a outputs a small-output heating instruction data to the heating control unit 4, and outputs current data of the heating coil 17 detected by the heating control unit 4. Get
It is determined whether there is an object to be heated such as a pan on the top plate 11, and if there is no object to be heated, the process proceeds to step 14 (step 14).
1). When an object to be heated is detected, the thermal data is fetched from the thermal detector 13 and converted into thermal element temperature data with reference to the thermal element temperature data table 16i. It is stored (step 2).

Next, it is determined whether or not the emissivity data of the object to be heated has been estimated, and if it has been estimated, the process proceeds to step 11 (step 3). On the other hand, when the emissivity data has not been estimated, the maximum value and the minimum value data in the thermosensitive element detected temperature data storage section 16e are updated by comparing them with the current values obtained in Step 2 (Step 4). Next, the difference between the maximum value and the minimum value of the thermosensitive element temperature data storage unit 16e is obtained, and the value is compared with a predetermined value to determine whether the fluctuation of the detected temperature of the thermosensitive element 12 is large. The process proceeds to step 10 (step 5). If it is determined that the variation in the detected temperature is small, the infrared data is taken in from the radiation detection unit 10, the current value is stored in the infrared data storage unit 16f, and the maximum value and the minimum value data are updated (step). 6).

Next, the difference between the maximum value and the minimum value in the infrared data storage section is obtained, and the difference is compared with a predetermined value to determine whether or not the fluctuation of the infrared data is large. The process proceeds (step 7). If it is determined that the change in the amount of infrared rays is small, the value of the timer counter 16d is incremented and compared with a predetermined value N (step 8). It is determined that the temperature of the back surface of the top plate 11 detected by the heat-sensitive element 12 and the amount of infrared radiation emitted from the object to be heated are stable, and the temperature of the object to be heated is set as a heat-sensitive detection temperature, and the infrared amount / temperature data table 16j is referred to. To estimate the emissivity of the object to be heated.

Here, a method for estimating the emissivity of the object to be heated from the temperature detected by the thermosensitive element and the amount of infrared radiation emitted from the object to be heated will be described with reference to FIG. In the figure, when the current value of the temperature detected by the thermosensitive element is Ta and the current value of the amount of infrared light detected by the radiation detection unit 10 is Wa, the data of the amount of infrared light and the data of the temperature are close to Wa and Ta in the infrared amount / temperature data table, respectively. The emissivity ea corresponding to the closest data is stored in the emissivity data storage unit as the emissivity of the object to be heated, and the emissivity is not estimated if there is no close data. (Step 9).

At this time, if the fluctuation of the temperature detected by the thermosensitive element 12 is large in step 5 or if the fluctuation of the infrared ray amount data is large in step 7, the minimum value of the timer counter and the thermosensitive element detected temperature data storage section 16e is stored. Value and maximum value,
The minimum value and the maximum value of the infrared data storage unit are initialized (Step 10). Next, it is determined whether the emissivity data is estimated (step 11). If the emissivity data is estimated, the emissivity data and the current value of the infrared ray data are referred to the infrared ray quantity / temperature data table 16j to determine the heating target. The radiation temperature is obtained and stored in the radiation temperature storage unit and the detected temperature storage unit (step 12). If the emissivity data has not been estimated, the current value of the thermosensitive element detected temperature data is stored in the detected temperature storage unit (step 12). If the object to be heated is not detected in step 1, the contents of the timer counter 16d, the emissivity data storage unit 16g, the thermosensitive element detected temperature storage unit 16e, the infrared ray amount data storage unit 16f, and the detected temperature storage unit 16k are read. Clear and end the process (step 13).

The emissivity data is estimated in step 9 by extracting a combination of data closest to the combination of the detected infrared ray amount and the temperature of the thermosensitive element from the infrared ray amount / temperature data table 16j. Is used as the emissivity of the object to be heated. However, the emissivity may be obtained by extracting a plurality of neighboring data and taking a weighted average from the distance.

In the description of the present embodiment, the infrared sensor 7 is arranged so as to detect infrared rays emitted from the side surface of the pot 2, but the present invention is not limited to this. For example, FIG.
May be configured to detect infrared rays radiated from the bottom of the pan 2 through the top plate 11 using an infrared transmitting material, or may be radiated from the surface of the pan 2 by another arrangement. The detected infrared rays may be detected. Furthermore, in the description of the present embodiment, the thermosensitive element 12 is
Although the case where the thermal contact is maintained indirectly through the and the top plate 11 has been described, the thermal contact may be directly maintained.

As described above, the top plate 1 by the heat-sensitive element 12
1 Simultaneous detection of the temperature of the back surface and detection of the amount of infrared light radiated from the object to be heated by the infrared sensor 9 to estimate the emissivity of the object to be heated, and the temperature of the object to be heated from the emissivity and the detected amount of infrared light , The light emitting element and the light receiving element are not required, and the configuration can be performed at low cost. Further, even when the amount of infrared light cannot be normally detected due to contamination of the light receiving portion of the infrared sensor 9 and emissivity data cannot be estimated, the temperature of the back surface of the top plate 11 detected by the thermosensitive element 12 is determined by the detected temperature of the object to be heated. As a result, stable temperature detection can be performed.

Embodiment 2 The present embodiment relates to a means for detecting dirt on the light receiving portion of the infrared sensor 9 and notifying the user of the same in the configuration of the first embodiment. Hereinafter, the present embodiment will be described with reference to the drawings.

FIG. 6 is a block diagram of the induction heating cooker 1 according to the present embodiment. In the figure, the same reference numerals are given to the same or corresponding parts as in the conventional example or the first embodiment, and the description is omitted. Reference numeral 16x denotes a radiation temperature disable flag provided in the temperature detection control unit 16 and set when an abnormality is detected in the light receiving unit of the infrared sensor 9. Fifteen
Reference numeral a denotes an LED provided in the display unit 15 and turned on when an abnormality is detected in the light receiving state, for requesting a state confirmation of the light receiving unit of the infrared sensor 9. Reference numeral 14a denotes an infrared sensor 9 abnormality reset input which is provided in the operation unit 14 and clears the radiation temperature disable flag 16x and turns off the LED 15a of the infrared sensor 9 light receiving unit state confirmation request when an input is made.

FIG. 7 is a characteristic diagram showing the relationship between the amount of infrared rays received at a certain emissivity ea and the temperature of the object to be heated, using dirt on the infrared sensor light receiving portion as a parameter. In the figure, reference numeral 71 denotes a characteristic curve showing the relationship between the amount of received infrared rays and the temperature of the object to be heated in a normal case where the light receiving portion of the infrared sensor 9 is not contaminated. The emissivity data ea of the object to be heated is estimated based on the detected infrared light amount Wa.

Numeral 72 is a characteristic curve showing the relationship between the amount of infrared light received and the temperature of the object to be heated when the light receiving portion of the infrared sensor 9 is partially contaminated by oily smoke or spills. 7 is a characteristic curve showing the relationship between the amount of received infrared rays and the temperature of the object to be heated when the object is covered with the infrared ray. When the temperature of the object to be heated reaches Tb and the light receiving portion of the infrared sensor 9 is normal (in the case of the characteristic curve 71),
The amount of detected infrared rays is Wb, and when the part is dirty (characteristic curve 7
2), the detected infrared ray amount is Wc, and when the dirt is severe (in the case of the characteristic curve 73), the detected infrared ray amount is Wa.
The radiation temperatures converted from the emissivity data ea and the amount of infrared radiation are Tb, Tc, and Ta, respectively. It can be seen that the error in the detected radiation temperature increases as the light receiving portion of the infrared sensor 9 becomes more dirty.

FIG. 8 is a flowchart showing an example of a processing operation when detecting contamination of the light receiving portion of the infrared sensor 9. The operation of the means for detecting the dirt on the light receiving portion of the infrared sensor 9 and notifying the user of the dirt will be described below with reference to FIGS. This process is periodically performed by the temperature detection control unit 16, and the emissivity of the object to be heated is estimated in the same manner as in the flowchart of FIG. 3 in the first embodiment.

First, the presence or absence of an object to be heated such as the pan 2 on the top plate 11 is determined. If there is no object to be heated, the process proceeds to step 84 (step 81). When an object to be heated is detected, the heat sensing data from the heat sensing unit 13 is taken in to detect the temperature of the thermosensitive element 12, the infrared ray amount data is taken in from the radiation detecting unit 10, and the radiation temperature is obtained from the emissivity data of the object to be heated. Conversion is performed (step 82). Next, a difference between the detected temperature of the thermosensitive element 12 and the radiation temperature is obtained, and it is determined whether or not a difference equal to or more than a predetermined value has occurred (step 83). If the detected temperature difference is small, the timer counter 16d is cleared (step 84), and if the detected temperature difference is large, the timer counter 16d is incremented to determine whether the state where the detected temperature difference is large has continued for a predetermined time or more. Judgment (Step 8
5) If it has continued, it is determined that the infrared sensor 9 light receiving section is dirty, the radiation temperature impossible flag 16x is set, and the confirmation request LED 1 of the infrared sensor 9 light receiving section is set.
The lighting signal of 5a is output to the display unit 15 (step 8).
6). It is determined whether the radiation temperature impossible flag 16x is set (step 87). If the flag is not set, the radiation temperature is set as the detected temperature of the object to be heated (step 88). The detected temperature of the heated object is set (step 89).

As described above, the difference between the temperature of the back surface of the top plate 11 detected by the thermal element 12 and the radiation temperature calculated from the amount of infrared rays detected by the infrared sensor 9 and the emissivity of the object to be heated continues to increase. In this case, it is determined that the infrared sensor 9 cannot be normally detected, and the user is notified via the display unit. Therefore, the light receiving unit of the infrared sensor 9 reliably detects dirt and keeps the detection of infrared light normal. be able to. Further, when contamination of the light receiving portion of the infrared sensor 9 is detected, the detection is switched to the temperature detection by the thermosensitive element 12, so that a large error does not occur in the detected temperature of the object to be heated.

Embodiment 3 FIG. Third Embodiment A third embodiment of the present invention is an induction heating cooker 1 provided with another means for detecting dirt on the light receiving section of the infrared sensor 9, and its block configuration is the same as that of the second embodiment shown in FIG. . FIG. 9 is a diagram showing an example of a temporal change in the temperature of the pan 2 and the detected temperature.
In the drawing, reference numeral 91 denotes a characteristic curve indicating a temporal change of the temperature of the pan 2, and 92 denotes a characteristic curve indicating a temporal change of a radiation temperature detection value detected when the light receiving portion of the infrared sensor 9 is normal. 2 can be detected with little time delay with respect to the temperature fluctuation. 93 is a thermosensitive element 12 provided on the back of the top plate 11
Is a characteristic curve showing the change over time of the detected temperature due to
A time delay such as heat conduction of the top plate 11 occurs. 94
Is a characteristic curve showing a temporal change of a radiation temperature detection value when dirt adheres to the light receiving portion of the infrared sensor 9, and the adhered substance is heated by infrared rays which are radiant heat from the pan 2, and the temperature rise is detected are doing.

The operation of the process for detecting the dirt on the light receiving portion of the infrared sensor 9 will be described below with reference to FIG. 9 and based on the flowchart of FIG. First, it is determined whether there is an object to be heated such as the pan 2 on the top plate 11 (step 101).
When an object to be heated is detected, the heat sensing data from the heat sensing unit 13 is taken in to detect the temperature of the thermosensitive element 12, the infrared ray amount data is taken in from the radiation detecting unit 10, and the radiation temperature is obtained from the emissivity data of the object to be heated. Convert (Step 10
2).

Next, the difference between the detected temperature of the thermosensitive element 12 and the radiation temperature is determined, and it is determined whether or not the temperature of the thermosensitive element 12 is higher than the radiation temperature by a predetermined value or more (step 103). If so, it is determined whether the radiation temperature detection value is increasing (step 104). If the temperature is rising, the timer counter 16d is incremented to determine the continuation time (step 105). If the continuation time is longer than the predetermined time, the radiation temperature detection value is delayed from the temperature of the thermosensitive element and the temperature of the pot is raised. It is determined that dirt is attached to the infrared sensor 9 light receiving unit, the radiation temperature disable flag 16x is set, and a lighting signal of the confirmation request LED of the infrared sensor 9 light receiving unit is output to the display unit ( Step 106). When the object to be heated is not detected, the thermal element 1
If the two temperatures are not higher than the radiation temperature, or if the radiation temperature detection value is falling, the timer counter 16d for determining the duration is cleared (step 107). Next, it is determined whether or not the radiation temperature impossible flag 16x is set (step 108). If the flag is not set, the radiation temperature is set as the detected temperature of the object to be heated (step 109). Is the detected temperature of the object to be heated (step 110).

As described above, the temperature of the back surface of the top plate 11 detected by the thermosensitive element 12, the amount of infrared light detected by the infrared sensor 9, and the radiation temperature calculated from the emissivity of the object to be heated are compared with the fluctuation speed. The temperature detection by the sensor 9 is the thermal element 1
2 detects that the response to the temperature change of the object to be heated is slower than the temperature detection, and determines that the infrared sensor 9 has not been able to detect normally. Then, the user can be notified. Further, when contamination of the light receiving portion of the infrared sensor 9 is detected, the detection is switched to the temperature detection by the thermosensitive element 12, so that a large error does not occur in the detected temperature of the object to be heated.

In the first to third embodiments, one of the temperature of the heat-sensitive element 12 and the temperature of the radiation of the object to be heated is determined as the temperature of the object to be heated according to the state of contamination of the light receiving portion of the infrared sensor 12. Alternatively, the higher of the detected temperature of the thermosensitive element 12 and the radiation temperature may be set as the detected temperature of the object to be heated.

[0041]

As described above, according to the present invention, the amount of infrared radiation radiated from the object to be heated is detected by the infrared sensor, and the temperature of the back surface of the top plate 11 is detected by the thermosensitive element 12, whereby the object to be heated is detected. It is possible to estimate the emissivity of the object, detect the temperature without time delay, and obtain the induction heating cooker 1 with a small error even when the light receiving portion of the infrared sensor 9 becomes dirty.

Further, since the estimation of the emissivity of the object to be heated is performed at the time when the detected infrared ray amount and the temperature of the thermosensitive element 12 are stabilized, there is an effect that a highly accurate radiation temperature can be obtained.

When the temperature of the heat-sensitive element 12 on the back surface of the top plate 11 is continuously higher than the radiation temperature of the object to be heated, the detected temperature of the object to be heated is regarded as the temperature of the heat-sensitive element 12. Stable temperature detection is possible even when the light receiving unit becomes dirty.

When the temperature of the thermosensitive element 12 on the back surface of the top plate 11 is continuously higher than the radiation temperature of the object to be heated, a request to confirm the light receiving state of the infrared sensor 9 is issued. The light receiving state can be kept normal.

When the response speed of the temperature of the thermosensitive element 12 on the back surface of the top plate 11 is faster than the radiation temperature of the article to be heated, the detected temperature of the article to be heated thereafter is defined as the temperature of the thermosensitive element 12.
Stable temperature detection is possible even when the light receiving portion of the infrared sensor 9 becomes dirty.

Further, when the response speed of the temperature of the thermosensitive element 12 on the back surface of the top plate 11 is faster than the radiation temperature of the object to be heated, the request for confirming the light receiving state of the infrared sensor 9 is notified. 9 can be normally maintained.

[Brief description of the drawings]

FIG. 1 is a block configuration diagram of an induction heating cooker 1 according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a temperature detection control unit of the induction heating cooker 1 according to Embodiment 1 of the present invention.

FIG. 3 is a flowchart of a detected temperature calculation process for detecting a temperature of a heated object of the induction heating cooker 1 according to Embodiment 1 of the present invention.

FIG. 4 is a characteristic diagram showing the relationship between the amount of infrared rays and the converted temperature using the emissivity as a parameter.

FIG. 5 is a block diagram showing another arrangement example of the infrared sensor of the induction heating cooker 1 according to Embodiment 1 of the present invention.

FIG. 6 is a block diagram of an induction heating cooker 1 according to Embodiment 2 of the present invention.

FIG. 7 is a characteristic diagram showing the relationship between the amount of infrared rays and the converted temperature for each contamination state of the infrared sensor light receiving unit.

FIG. 8 is a flowchart of an infrared sensor dirt detection process 1 for determining a light receiving state of the infrared sensor in the induction heating cooker 1 according to Embodiment 2 of the present invention.

FIG. 9 is a characteristic diagram showing a change in temperature of an object to be heated, a change in detected temperature of a thermosensitive element, and a change in radiation temperature.

FIG. 10 is another flowchart of the infrared sensor dirt detection processing for determining the light receiving state of the infrared sensor in the induction heating cooker 1 according to Embodiment 3 of the present invention.

FIG. 11 is a block diagram showing a configuration of temperature detection of a conventional cooking device.

FIG. 12 is a characteristic diagram showing a relationship between emissivity and reflectance.

FIG. 13 is a characteristic diagram showing the relationship between the amount of infrared rays and the converted temperature using the emissivity as a parameter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cooking device, 2 pots, 3 arithmetic control processing parts, 4 heating control parts, 5 light emitting elements, 6 light receiving sensors, 7 light emitting control parts, 8 reflection detection parts, 9 infrared sensors, 10 radiation detection parts, 11 top plates 12 Thermal element, 13 Thermal detector, 14 Operation section, 14a Abnormal reset input, 15
Display unit, 15a LED for status confirmation request, 16 temperature detection control unit, 16a operation control unit, 16b control program data, 16c timer unit, 16d timer counter, 16e thermosensitive element detected temperature data storage unit, 16f
Infrared data storage, 16g emissivity data storage, 16
h radiation temperature data storage section, 16i thermosensitive element temperature data table, 16j infrared ray quantity / temperature data table,
16k detection temperature storage unit, 16x radiation temperature disable flag, 17 heating coil

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Sato 1728-1, Koeda, Oaza, Hanazono-cho, Osato-gun, Saitama Prefecture Inside Mitsubishi Electric Home Equipment Co., Ltd. Mitsubishi Electric Home Equipment Co., Ltd. F term (reference) 2G066 AC05 AC16 BB15 BC15 CA15 CB05 3K051 AB02 AC33 AC42 AD24 AD28 CD07 CD38 CD40 CD44 3L086 AA01 CB05 CB17 DA20

Claims (6)

[Claims] 1. An infrared sensor for detecting infrared rays emitted from an object to be heated, a thermosensitive element in thermal contact with the object to be heated, an infrared ray amount detected by the infrared sensor, and an infrared ray detected by the thermosensitive element. Estimating means for estimating the emissivity of infrared rays radiated from the object to be heated,
Induction heating means for calculating a radiation temperature of the object to be heated from the emissivity of the object to be heated estimated by the estimating means and the amount of infrared rays detected by the infrared sensor. Cooking device. 2. The estimating means for estimating the emissivity for the object to be heated is characterized in that the fluctuations in the temperature detected by the thermosensitive element and the amount of infrared light detected by the infrared sensor continue for a predetermined time or more and fall within a predetermined range. The induction heating cooker according to claim 1, wherein the induction heating cooker is executed when the temperature is within the range. 3. The temperature detected by the thermosensitive element is equal to or greater than a predetermined temperature difference for a predetermined time, and then equal to or greater than a predetermined temperature difference with respect to a radiation temperature calculated from an amount of infrared rays detected by the infrared sensor and an emissivity of the object to be heated. 3. The induction heating cooker according to claim 1, wherein, in the case, the temperature of the object to be heated thereafter is set as a temperature detected by the thermosensitive element. 4. 4. The method according to claim 1, wherein the temperature detected by the thermosensitive element is a predetermined temperature difference and then a predetermined temperature difference or more with respect to a radiation temperature calculated from the amount of infrared rays detected by the infrared sensor and the emissivity of the object to be heated. The induction heating cooker according to claim 1, further comprising a state confirmation request unit that requests confirmation of a light incident state of the infrared sensor in a case where the condition is satisfied. 5. When the temperature detected by the thermosensitive element fluctuates faster than the radiation temperature calculated from the amount of infrared rays detected by the infrared sensor and the emissivity of the object to be heated, The induction heating cooker according to claim 1, wherein the temperature is set as a temperature detected by the thermosensitive element. 6. When the temperature detected by the heat-sensitive element fluctuates faster than the radiation temperature calculated from the amount of infrared light detected by the infrared sensor and the emissivity of the object to be heated, light is incident on the infrared sensor. 3. The induction heating cooker according to claim 1, further comprising a state confirmation requesting means for requesting a state confirmation.