JP6628897B2 - Burn detection system, cookware, and burn detection method - Google Patents

Description

  The present invention relates to a focus detection system, a cooking appliance, and a focus detection method.

  2. Description of the Related Art In recent years, cookers that heat cooked items contained in cooking utensils such as pots by induction heating have become widespread. Some cookers of this type include a cooking support function that automatically performs control to suppress heating or notifies the user through an operation interface in accordance with the operation of the user or the state of cooking.

  As one of such cooking assisting functions, a focus detection is known (for example, Patent Document 1).

Japanese Patent No. 5838314

  As disclosed in Patent Literature 1, in the conventional detection of burning, generally, the temperature of the bottom of the cooking utensil is measured, and when the measured temperature exceeds a predetermined threshold, the burning of the food in the cooking utensil is detected. Is adopted.

  In the conventional scorching detection that relies on a change in temperature, good detection accuracy can be expected when a juicy food such as a boiled dish is to be detected.

  However, in the case of cooking by baking a poorly juicy solid food such as meat or processed meat, the temperature of the cooking utensil tends to be high even before scorching occurs, and since the temperature change is small, It is difficult to accurately detect the focus by the conventional method.

  The present invention has been made in order to solve the above-described problems, and has an object to provide a burnt detection system and the like that can accurately detect burnt even in solid cooked food with poor juice. .

In order to achieve the above object, a focus detection system according to the present invention includes:
Heating means for heating the food;
Impedance measuring means for measuring the impedance of the food,
Temperature measuring means for measuring the temperature of the food,
A detection unit that detects the sticking of the food based on the measured impedance and a threshold determined according to the measured temperature,
Notification means for notifying the user that the sticking has been detected.

  In the present invention, the sticking of the food is detected based on the impedance of the food and a threshold value determined according to the temperature of the food. For this reason, even if it is a solid cooked food with poor juice, it is possible to accurately detect the sticking.

FIG. 1 is a diagram illustrating a configuration of a focus detection system according to a first embodiment of the present invention. Diagram for explaining the arrangement of electrodes Block diagram showing the configuration of the impedance measuring device Block diagram showing the configuration of the measurement circuit The figure which shows the example of the mark formed in a cooking appliance Diagram for explaining a modification of the shape of the electrode Schematic diagram showing the appearance of the cooking device The figure which shows an example of the operation reception part with which a cooking device is provided. FIG. 2 is a block diagram illustrating a hardware configuration of a control unit included in the cooking device. The figure which shows the function structure of the control part with which a cooking device is provided. Graph showing the relationship between cooking time and electrical impedance Flow chart showing the procedure of the focus detection process Diagram for explaining the arrangement of a plurality of electrode pairs Diagram for explaining the arrangement of a plurality of electrode pairs FIG. 2 is a block diagram illustrating a configuration of an impedance measuring device according to a modification of the first embodiment. FIG. 2 is a block diagram illustrating a configuration of an impedance measuring device according to a modification of the first embodiment. FIG. 3 is a diagram illustrating a configuration of a focus detection system according to a modification of the first embodiment. The figure which shows the structure of the cooking appliance which concerns on Embodiment 2 of this invention. FIG. 4 is a block diagram illustrating a configuration of a focus detection device according to a second embodiment. Diagram for explaining a focus detection system according to another embodiment

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram illustrating a configuration of a focus detection system 1 according to the first embodiment of the present invention. The scorching detection system 1 is a system that detects scorching of the food 4 during cooking, and includes a cooking utensil 2 and a heating cooker 3.

  The cooking utensil 2 is a cooking utensil for baking the food 4 (for example, a hamburger), and in this embodiment, is a frying pan. The cooking utensil 2 is provided with an impedance measuring device 20 as shown in FIGS. 1 and 2, and further, as shown in FIG. 2, a pair of electrodes 21a and 21b. The impedance measuring device 20 (impedance measuring means) is a device that measures the electric impedance of the food 4 placed on the bottom of the pot of the cooking utensil 2, and is embedded in a handle of the cooking utensil 2.

  The electrodes 21a and 21b are plate-shaped and made of a highly conductive metal. The electrodes 21a and 21b are provided at the center of the pan bottom surface (cooking surface) so as to face each other. The electrodes 21a and 21b are respectively connected to the impedance measuring device 20 via signal lines. Each signal line connects between the electrodes 21a and 21b and the impedance measuring device 20 through the inside of the pot bottom and the inside of the handle.

  As shown in FIG. 3, the impedance measurement device 20 includes a measurement circuit 200, a communication unit 201, and a control unit 202. The impedance measuring device 20 further includes a power supply unit (not shown) such as a primary battery or a secondary battery. In addition, electric power may be supplied to the impedance measuring device 20 from the heating cooker 3 by non-contact electric power transmission by electromagnetic induction.

  The measurement circuit 200 includes an oscillator 210, a voltage sensor 211, and a current sensor 212, as shown in FIG. The oscillator 210 generates a voltage signal having a predetermined frequency (for example, 100 Hz, 1 kHz, 100 kHz, or the like). The voltage sensor 211 measures a potential difference between the electrodes 21a and 21b, and the current sensor 212 measures an alternating current flowing between the electrodes 21a and 21b. The signal indicating the measurement result of the voltage sensor 211 and the signal indicating the measurement result of the current sensor 212 are output to the control unit 202.

  Although not shown, the control unit 202 includes two input ports for inputting signals output from each of the voltage sensor 211 and the current sensor 212 of the measurement circuit 200, a CPU (Central Processing Unit), and a ROM (Read Only). Memory) and a RAM (Random Access Memory). The control unit 202 controls the electric impedance between the electrodes 21a and 21b based on the measurement result of the voltage sensor 211 and the measurement result of the current sensor 212, in other words, the electric impedance of the food 4 placed on the electrodes 21a and 21b. Measure the impedance (combined impedance). As a method of measuring the electrical impedance, for example, a known method such as a bridge method, a resonance method, or an IV method can be adopted.

  The communication unit 201 (transmission means) is a communication interface for performing wireless communication with the cooking device 3. The communication unit 201 wirelessly communicates with the cooking device 3 by a short-range wireless method such as RFID (Radio Frequency Identification) and NFC (Near Field Communication). The wireless communication between the impedance measuring device 20 and the cooking device 3 may be performed by Wi-Fi (registered trademark) or Bluetooth (registered trademark).

  The control unit 202 transmits data (measurement data) indicating the measured electrical impedance to the heating cooker 3 via the communication unit 201 at intervals of several seconds (for example, 5 seconds).

  In addition, as shown in FIG. 5, a mark 22 that can be visually recognized by a user may be formed by performing a surface treatment (surface processing) on a central portion of the bottom of the pot of the cooking utensil 2. This makes it easier for the user to place the food 4 on the electrodes 21a and 21b.

  In addition, the electrodes 21a and 21b may have a bow shape as shown in FIG. 6, instead of a plate shape (linear shape). By doing so, the electrical impedance can be measured at a portion of the cooking product 4 where the amount of heat is easily transmitted, that is, the distance from the center where the thermal power is easily transmitted, so that the accuracy of the focus detection can be improved.

  Returning to FIG. 1, the heating cooker 3 is an induction heating (IH) cooker, and includes a top plate 31 and an operation reception unit 32 provided on an upper surface side of a substantially rectangular parallelepiped housing 30, and an inside of the housing 30. It includes a housed heating coil 33, an inverter circuit 34, a communication unit 35, a temperature sensor 36, and a control unit 37.

  The top plate 31 is made of tempered glass. The heating coil 33 is provided below the top plate 31, and generates an induction magnetic field when a high-frequency current supplied from the inverter circuit 34 flows under the control of the control unit 37 described below. The induction magnetic field acts on the cooking utensil 2 placed on the top plate 31, and the cooking utensil 2 is heated (so-called induction heating). As a result, the top plate 31 indirectly heats the food 4 contained in the cooking utensil 2. The top plate 31 and the heating coil 33 constitute the heating means of the present invention.

  The heating coil 33 is connected to an inverter circuit 34 via a signal line. The inverter circuit 34 supplies a high-frequency current to the heating coil 33 under the control of the control unit 37. In the present embodiment, the number of the top plates 31 is one. However, when the number of the top plates 31 is plural, the heating coil 33 and the inverter circuit 34 are provided corresponding to each of the top plates 31.

  The operation reception unit 32 is provided on the upper surface on the near side (that is, the user side) of the housing 30 as illustrated in FIG. 7, and includes a power button 320 and a touch panel 321. The power button 320 is a button for receiving on / off of the power of the cooking device 3 from a user. The touch panel 321 includes, for example, a liquid crystal display device and a capacitive touch sensor. Under the control of the control unit 37, the touch panel 321 displays an operation screen for receiving an operation related to cooking from the user, receives an operation by the user, and connects a signal related to the received operation via a signal line. It is sent to the unit 37.

  The operation screen displayed on the touch panel 321 includes a cooking menu screen and a thermal power setting screen as shown in FIG. The user can select a desired cooking menu via the cooking menu screen, and can set the heating power (heating intensity) to a desired strength via the heating power setting screen. In the example of FIG. 8, “cooked food” is selected as the cooking menu, and the heat intensity is set to “medium”.

  Returning to FIG. 1, the communication unit 35 (receiving means) is a communication interface for wirelessly communicating with the impedance measuring device 20 by a short-range wireless method such as RFID or NFC.

  The temperature sensor 36 (temperature measuring means) is installed at the center of the back surface of the top plate 31, indirectly measures the temperature of the pot bottom of the cooking utensil 2, and sends a signal indicating the measurement result to the control unit 37 via a signal line. Output to The temperature sensor 36 includes, for example, a thermosensitive element such as a thermistor, or an infrared sensor that detects the amount of infrared energy radiated from the bottom of the pot of the cooking utensil 2 and outputs a voltage corresponding to the detected amount of energy. You.

  As illustrated in FIG. 9, the control unit 37 includes a CPU 370, a ROM 371, a RAM 372, a secondary storage device 373, and a plurality of ports 374. These components are interconnected via a bus 375.

  The CPU 370 controls the cooking device 3 as a whole. The ROM 371 stores a plurality of firmware, data used when executing the firmware, and the like. The RAM 372 is used as a work area of the CPU 370. The secondary storage device 373 is configured by a readable and writable nonvolatile semiconductor memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) and a flash memory, and stores programs and data related to focus detection. In addition, in addition to this, the secondary storage device 373 stores a program and data for performing a function as a general IH cooker.

  The port 374 is an interface for inputting and outputting signals exchanged with the operation receiving unit 32, the inverter circuit 34, the communication unit 35, and the temperature sensor 36.

  The control unit 37 functionally includes an impedance acquisition unit 3700, a temperature acquisition unit 3701, a focus detection unit 3702, a heating reduction unit 3703, and a notification unit 3704, as shown in FIG. These functional units are realized by the CPU 370 executing a program related to focus detection stored in the secondary storage device 373.

  The impedance acquisition unit 3700 acquires the electric impedance of the food 4. Specifically, the impedance acquisition unit 3700 acquires the measurement data transmitted from the impedance measurement device 20 via the communication unit 35, and stores the acquired measurement data in the RAM 372.

  The temperature acquisition unit 3701 acquires the surface temperature of the food 4. In the present embodiment, the temperature based on the measurement result of the temperature sensor 36 is regarded as the surface temperature of the food 4. Specifically, the temperature acquisition unit 3701 reads out a signal from the port 374 corresponding to the temperature sensor 36, that is, a signal indicating the measurement result output from the temperature sensor 36 at regular time intervals (for example, every 5 seconds), The read signal is converted into data (temperature data) indicating the temperature (° C.). The temperature acquisition unit 3701 stores the temperature data (that is, the surface temperature of the food 4) thus acquired in the RAM 372.

  The burning detection unit 3702 (detection means) compares the electrical impedance of the food 4 with a threshold value (hereinafter, referred to as a “main threshold”) determined according to the surface temperature of the food 4, thereby detecting the food 4. Detects burning.

  Here, the relationship between the electrical impedance and the occurrence of burning will be described. FIG. 11 is a graph showing the relationship between the cooking time of the hamburger steak and the electrical impedance obtained by the experiment. In this experiment, a plurality of raw hamburgers having the same conditions (components, size, mass, etc.) before cooking (heating) were prepared, and the electrical impedance was measured after cooking for different times (1 to 5 minutes). The measurement of the electrical impedance was performed after the hamburger after each cooking was sufficiently cooled to about room temperature.

  From this experiment, the inventors found that the longer the cooking time (heating time), that is, the more the state of the food (hamburger) changes, the greater the scorch, the higher the electrical impedance of the food. Was found. On the other hand, it is known that the electrical impedance tends to decrease as the temperature increases. The inventors have created a new method for detecting the sticking of the food from these findings.

  Specifically, first, the focus detection unit 3702 calculates a correction value by multiplying the surface temperature (° C.) of the food 4 obtained by the temperature obtaining unit 3701 by a predetermined coefficient (temperature coefficient). . The temperature coefficient is derived, for example, from data indicating the relationship between temperature and electrical impedance obtained by experiments.

  Next, the focus detection unit 3702 calculates this threshold value by subtracting the above correction value from a predetermined reference threshold value. The reference threshold is, for example, 50 kΩ. Then, the focus detection unit 3702 determines whether or not the acquired electrical impedance of the food 4 exceeds the calculated main threshold. As a result, when the electrical impedance of the food 4 exceeds the threshold value, the focus detection unit 3702 detects the focus, that is, determines that the food 4 has focus.

  The heating reducing unit 3703 (heating reducing unit), when the burning detection unit 3702 detects the burning, instructs the inverter circuit 34 to stop the heating or reduce the heating power (heating intensity).

  The notifying unit 3704 (notifying unit) notifies the user of the occurrence of the sticking when the sticking detection unit 3702 detects the sticking. Specifically, the notification unit 3704 causes a sound output unit (not shown) included in the operation reception unit 32 to output a warning sound (for example, an electronic sound such as a buzzer sound) and a voice message. In the case of a voice message, for example, it is informed that burning has occurred, or that the power has been automatically stopped or the heating power has been reduced.

  In addition to the output of the above-mentioned warning sound and voice message, the notification unit 3704 also informs the touch panel 321 of the operation reception unit 32 that a touch has occurred, that the touch panel 321 has automatically stopped or that the heating power has been reduced. It may be displayed as characters or images, or an LED (not shown) provided in the operation receiving unit 32 may be displayed in a predetermined color (for example, red) or may be displayed in a blinking manner.

  The notification unit 3704 communicates with a portable terminal (smartphone, tablet terminal, or the like) owned by the user via the communication unit 35 instead of or in combination with the above-described notification. The occurrence, occurrence of the automatic stop or lowering of the heating power may be displayed in characters or images, or a warning sound or a voice message may be output. Alternatively, the notification unit 3704 may communicate with a controller of a home energy management system (HEMS) via the communication unit 35 to cause the user interface of the HEMS (operation terminal such as a tablet terminal) to perform the above notification. In this case, the heating cooker 3 and the controller of the HMES are communicatively connected, for example, via a network conforming to ECHONET Lite.

  FIG. 12 is a flowchart illustrating the procedure of the focus detection process executed by the control unit 37 of the heating cooker 3. The focus detection process is started when the user performs an operation related to the start of cooking via the touch panel 321.

  When acquiring the electric impedance of the food 4, that is, the measurement data transmitted from the impedance measurement device 20 of the cooking utensil 2 via the communication unit 35 (Step S <b> 101; YES), the impedance acquisition unit 3700 transmits the acquired measurement data. It is stored in the RAM 372. Note that the impedance measuring device 20 of the cooking utensil 2 is activated when a switch (power switch or the like) (not shown) for starting measurement provided by the cooking utensil 2 is turned on by a user, and the above-described operation, that is, The operation of measuring the electrical impedance and transmitting the measurement data is repeated.

  When the heating cooker 3 is not performing the heating operation (step S102; NO), the control unit 37 ends the focus detection process. On the other hand, when the heating operation is being performed (Step S102; YES), the temperature acquisition unit 3701 acquires the surface temperature of the food 4 as described above (Step S103). The focus detection unit 3702 calculates a correction value based on the surface temperature of the food 4 acquired by the temperature acquisition unit 3701 (step S104). The correction value is calculated by multiplying the surface temperature (° C.) of the food 4 by the above-described temperature coefficient.

  Next, the focus detection unit 3702 calculates the main threshold based on the reference threshold and the calculated correction value (step S105). This threshold is calculated by subtracting the correction value from a reference threshold (for example, 50 kΩ).

  The focus detection unit 3702 determines whether the electric impedance of the food 4 exceeds the calculated main threshold (step S106). If the electric impedance of the food 4 does not exceed the threshold (step S106; NO), the process returns to step S101, and the impedance acquiring unit 3700 continues until the next measurement data is transmitted from the impedance measuring device 20 of the cooking utensil 2. stand by. When the impedance measuring device 20 continuously measures the electrical impedance, the standby time of the impedance acquiring unit 3700 is, for example, 5 seconds.

  On the other hand, when the electric impedance of the food 4 exceeds the main threshold (step S106; YES), the heating reducing unit 3703 instructs the inverter circuit 34 to stop heating, or the heating power (heating intensity). Is reduced (step S107). In addition, the notification unit 3704 notifies the user of the occurrence of burning (step S108). For example, the notification unit 3704 causes a sound output unit (not shown) included in the operation reception unit 32 to output a warning sound or a voice message, or causes the touch panel 321 to display information on occurrence of a focus.

  As described above, in the burning detection system 1 according to the first embodiment of the present invention, the cooking device 3 includes the electric impedance of the food 4 measured by the impedance measuring device 20 of the cooking utensil 2 and the temperature sensor 36. Is detected based on the measured surface temperature of the food 4. For this reason, even if the cooked food 4 is a poorly juicy solid food such as beef, pork, chicken, or hamburger, it is possible to accurately detect the sticking.

  The first embodiment may be modified as follows.

(Modification 1)
For example, as shown in FIGS. 13 and 14, a plurality of electrode pairs (21-1a and 21-1b, 21-2a and 21-2b, and 21-3a and 21-3b) have different distances between the electrodes. May be provided on the cooking utensil 2. In this case, the impedance measurement device 20 includes measurement circuits 200-1 to 200-3 corresponding to each electrode pair, as shown in FIG. Alternatively, as shown in FIG. 16, an electrode switching unit 203 may be provided, and the electrode pairs connected to the measurement circuit 200 may be sequentially switched according to a command from the control unit 202. The electrode switching unit 203 is configured by a mechanical relay or a semiconductor relay.

  The control unit 202 of the impedance measuring device 20 may transmit the measurement data in which all the measurement results of each electrode pair are stored to the cooking device 3, or may transmit the measurement data of each electrode pair to the cooking device 3 sequentially. May be.

  By doing so, the control unit 37 of the cooking device 3 takes into account a plurality of electric impedances corresponding to the distance between the electrodes, that is, a plurality of electric impedances corresponding to the size of the measurement range of the food 4. Sticking detection can be performed. This makes it possible to determine the size of the burning and the internal state of the food 4, and to prevent inconveniences such as, for example, detecting a small burning such as underburning and stopping the heating.

  In addition, since a plurality of foods 4 may be cooked at the same time, a plurality of electrode pairs may be arranged at various positions on the bottom surface of the pot of the cooking utensil 2.

(Modification 2)
Further, as shown in FIG. 17, the detection system 1 may further include an odor sensor 5 (odor measurement unit) and a camera 6 (image pickup unit). The odor sensor 5 (odor measurement unit) and the camera 6 (image pickup unit) are installed in a range hood, and are communicably connected to the cooking device 3 by wire or wirelessly. The odor sensor 5 targets a light (low molecular weight) component or a sulfur component as a measurement target, and transmits a signal indicating the measurement result to the heating cooker 3. The camera 6 includes an image sensor such as a charge-coupled device (CCD) and a complementary metal oxide semiconductor (CMOS). The camera 6 captures an image of the lower region at intervals of several seconds (for example, 5 seconds) and transmits data indicating the captured image to the cooking device 3.

  Then, the control unit 37 of the heating cooker 3 detects the focus of the food 4 in consideration of the measurement result of the odor sensor 5 and the image captured by the camera 6. By doing so, the accuracy of the focus detection is further improved.

  If a ventilation fan is installed in the cabinet in which the cooking device 3 is placed, the odor sensor 5 may be installed near the ventilation fan. There are various places where the camera 6 can be installed, and the camera 6 may be installed in a place where the entire area of the bottom of the pot of the cooking utensil 2 placed on the heating cooker 3 can be imaged, such as a ceiling just above the cooking heater 3.

(Modification 3)
In addition, a temperature sensor (not shown) connected to the impedance measuring device 20 via a signal line is provided at the center of the bottom surface of the pot of the cooking utensil 2. The measurement data may be transmitted to the cooking device 3. The temperature sensor in this case is constituted by a thermosensitive element such as a thermistor, directly measures the temperature (surface temperature) of the food 4 and outputs a signal indicating the measurement result to the impedance measuring device 20 via a signal line. .

  By doing so, the control unit 37 of the heating cooker 3 can calculate the correction value by using a temperature that is close to the actual surface temperature of the food 4, thereby improving the accuracy of the focus detection.

(Modification 4)
Further, in the measurement circuit 200 of the impedance measurement device 20, the frequency of the voltage signal generated by the oscillator 210 may be changed according to a command from the control unit 202. The control unit 202 selects a frequency set in advance according to the type of the food 4. The type of the food 4 is specified by the user. In this case, for example, the cooking utensil 2 is provided with a designation receiving unit (not shown) such as a switch or a dial for allowing the user to specify the type of the food 4 (beef, pork, chicken, hamburger, etc.). Then, the designation receiving unit may send a signal indicating the type of the designated food 4 to the control unit 202. Alternatively, the impedance measuring device 20 allows the user to specify the type of the food 4 via the operation reception unit 32 of the heating cooker 3, and transmits the information indicating the type of the specified food 4 by communication. It may be obtained from the cooking device 3.

  By doing so, the electrical impedance can be measured at an appropriate frequency according to the type of the food 4, so that the accuracy of focus detection can be improved.

(Modification 5)
Further, the control unit 37 of the heating cooker 3 may start the burning detection process not immediately after the start of cooking (start of heating) but when a predetermined start condition is satisfied. . The start conditions include, for example, when the temperature measured by the temperature sensor 36 rises to a predetermined temperature, when the integrated value of the power consumed by the inverter circuit 34 after the start of cooking reaches the predetermined power value, Falls down to a predetermined lower limit, a case where a predetermined time has elapsed since the start of cooking, a case where the food 4 is placed on the cooking utensil 2, a combination thereof, and the like. Whether or not the food 4 is placed on the cooking utensil 2 may be determined by providing a weight sensor (not shown) in the heating cooker 3 and based on the measurement result of the weight sensor.

  By providing the above start condition, erroneous detection can be prevented.

(Modification 6)
Further, the control unit 37 of the heating cooker 3 may execute the above-described focus detection process only when a specific cooking menu (for example, grilled food) is selected. In this case, when another specific cooking menu (for example, stewed) is selected, the detection of the burning based on the change in the temperature may be performed as in the related art. Alternatively, an on / off button (including a GUI (Graphical User Interface) button) for focus detection is provided in the operation reception unit 32, and the control unit 37 of the heating cooker 3 determines whether or not the focus detection is on. The above-described focus detection process may be performed.

(Modification 7)
The control unit 37 of the heating cooker 3 may adjust the reference threshold value according to the selected cooking menu, the type of the food 4, and the user's preference of the baking condition (rare, medium, well-done, etc.). In this case, the user may be allowed to specify the type of the food 4 and the preference of the baking condition via the operation reception unit 32. When the cooking utensil 2 is provided with a specification receiving unit for the user to specify the type of the food 4 as in the above-described modification 4, the control unit 37 determines the type of the food 4 May be obtained from the impedance measuring device 20 of the cooking appliance 2 by communication.

(Modification 8)
Further, the electrodes 21a and 21b and the impedance measuring device 20 may be configured by a sheet-like IC so that the user can arrange the impedance measuring device 20 at an arbitrary position on the bottom of the pot of the cooking utensil 2.

(Embodiment 2)
Subsequently, a second embodiment of the present invention will be described. In the following description, components and the like common to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 18 shows the configuration of the cooking utensil 2A according to the present embodiment. The cookware 2A is provided with a focus detection device 23 instead of the impedance measurement device 20 of the first embodiment. Further, a temperature sensor 24 is provided on the cooking utensil 2A.

  The temperature sensor 24 is provided at the center of the bottom surface of the pot of the cooking utensil 2A, directly measures the temperature (surface temperature) of the food 4 and sends a signal indicating the measurement result to the focus detection device 23 via a signal line. Output. The temperature sensor 24 (temperature measuring means) is constituted by a thermosensitive element such as a thermistor.

  As shown in FIG. 19, the focus detection device 23 includes a measurement circuit 230, a communication unit 231, and a control unit 232. The measurement circuit 230 has the same configuration as the measurement circuit 200 of the first embodiment (see FIG. 4).

  The communication unit 231 (communication means) is a communication interface for performing wireless communication with the cooking device 3. The communication unit 231 communicates with the heating cooker 3 by a wireless method such as Wi-Fi (registered trademark) or Bluetooth (registered trademark).

  Although not shown, the control unit 232 (detection unit, notification unit) includes a plurality of input ports for inputting a signal output from the measurement circuit 230 and a signal output from the temperature sensor 24, a CPU, a ROM, , RAM. The functions of the control unit 232 relating to the following processing are realized by the CPU executing a program relating to focus detection stored in the ROM. The measuring circuit 230 and the control unit 232 constitute an impedance measuring unit.

  The control unit 232, like the control unit 202 of the first embodiment, sets the electric impedance between the electrodes 21a and 21b, in other words, the electric impedance of the food 4 placed on the electrodes 21a and 21b in the order of several seconds (for example, 5 seconds). Further, the control unit 232 reads a signal from an input port corresponding to the temperature sensor 24, that is, a signal indicating a measurement result output from the temperature sensor 24 in synchronization with the measurement of the electrical impedance, and reads the read signal as a temperature. (° C.).

  Then, the control unit 232 performs the focus detection by the same method as the focus detection unit 3702 of the first embodiment. That is, the control unit 232 calculates a correction value by multiplying the surface temperature (° C.) of the food 4 measured by the temperature sensor 24 by the same temperature coefficient as in the first embodiment. Next, the control unit 232 calculates this threshold by subtracting the calculated correction value from a predetermined reference threshold (for example, 50 kΩ).

  The control unit 232 determines whether the measured electrical impedance of the food 4 exceeds the calculated main threshold. As a result, when the electric impedance of the food 4 exceeds the threshold value, the control unit 232 detects the sticking, that is, determines that the cooking 4 has the sticking. When the control unit 232 detects the burning, the control unit 232 generates data (notification data) for notifying that the burning has occurred, and transmits the data to the heating cooker 3 via the communication unit 231.

  It should be noted that the focus detection device 23 is activated when a switch (not shown) (not shown) for starting the focus detection provided on the cooking utensil 2A is turned on by a user, and starts the above operation. .

  When the communication unit 35 receives the above-described notification data transmitted from the focus detection device 23 of the cooking utensil 2A, the control unit 37 of the heating cooker 3 of the present embodiment notifies the user of the occurrence of the focus. Specifically, the control unit 37 causes a sound output unit (not shown) included in the operation reception unit 32 to output a warning sound (for example, an electronic sound such as a buzzer sound) and a voice message. In the case of a voice message, for example, it is informed that burning has occurred, or that the power has been automatically stopped or the heating power has been reduced.

  Further, in addition to the output of the above-mentioned warning sound and voice message, the control unit 37 also informs the touch panel 321 of the operation reception unit 32 that the sticking has occurred and that the touch panel 321 has automatically stopped or reduced the heating power. It may be displayed as characters or images, or an LED (not shown) provided in the operation receiving unit 32 may be displayed in a predetermined color (for example, red) or may be displayed in a blinking manner.

  The control unit 37 communicates with a portable terminal (smartphone, tablet terminal, or the like) owned by the user via the communication unit 35 instead of or in combination with the above-described notification, and the portable terminal is focused on. The occurrence, occurrence of the automatic stop or lowering of the heating power may be displayed in characters or images, or a warning sound or a voice message may be output. Alternatively, the control unit 37 may communicate with the controller of the HEMS via the communication unit 35 to cause the HEMS user interface (an operation terminal such as a tablet terminal) to perform the above-described notification.

  As described above, in the second embodiment, the burn-in detection device 23 of the cooking utensil 2A uses the measured electrical impedance of the food 4 and the surface temperature of the food 4 measured by the temperature sensor 24 to detect the food 4 Performs burn detection. For this reason, even if the cooked food 4 is a poorly juicy solid food such as beef, pork, chicken, or hamburger, it is possible to accurately detect the sticking.

  In addition, since the temperature of the food 4 is measured by the temperature sensor 24 provided on the cooking utensil 2A, the correction value can be calculated using a temperature close to the actual surface temperature of the food 4, so that the accuracy of the focus detection can be calculated. Improvement can be achieved.

  The present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention.

  For example, as shown in FIG. 20, a measuring circuit 38 similar to the measuring circuit 200 in the first embodiment is added to the cooking device 3 in the first embodiment so that the electric impedance can be measured by the cooking device 3. Is also good. In this case, although the cooking utensil 2B is provided with the electrodes 21a and 21b, the impedance measuring device 20 is not required.

  On the top plate 31 of the heating cooker 3 in the above case, conductors 310a and 310b that are electrically connected to the measurement circuit 38 are provided so as to be exposed on the surface of the top plate 31. The distance between the conductors 310a and 310b on the surface of the top plate 31 is substantially the same as the distance between the electrodes 21a and 21b. Therefore, when the cooking utensil 2B is placed on the top plate 31, the electrodes 21a, 21b and the conductors 310a, 310b can be brought into contact, and the electrical impedance of the food 4 can be measured. Note that at least one of the electrodes 21a and 21b and the conductors 310a and 310b may be formed of a magnet to induce contact.

  The cooking utensil of the present invention is not limited to a frying pan and may be a pot-shaped one.

  The cooking device of the present invention may be a device in which the cooking device and the cooking utensil are integrated such as a hot plate, an electric griddle, a grill pan, and the like. The configuration is such that the cooking utensil 2 and the heating cooker 3 are integrated.

  The cooking device of the present invention is not limited to the IH cooking device, but may be a gas cooking device or a heating device of a radiant heater type.

  In addition, in the focus detection by the heating cooker 3 of the first embodiment and the focus detection device 23 of the second embodiment, not only the electric impedance of the food 4 but also L (inductance), C () in the electrical impedance of the food 4. Any one component of capacitance (capacitance) and R (resistance) may be employed. For example, when the R component is employed, the impedance measuring device 20 and the focus detection device 23 may be provided with a DC power supply instead of the oscillator 210 and the voltage sensor 211, so that the product cost can be reduced. From experiments, it has been found that the R component and the L component of the electrical impedance also tend to increase as the degree of burn increases, and that the C component tends to decrease as the degree of burn increases. I have.

  Further, all or a part of each functional unit (see FIG. 10) of the control unit 37 included in the heating cooker 3 of the first embodiment may be realized by dedicated hardware. The dedicated hardware is, for example, a single circuit, a composite circuit, a programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof.

  The present invention is capable of various embodiments and modifications without departing from the broad spirit and scope. Further, the above-described embodiments are for describing the present invention, and do not limit the scope of the present invention. That is, the scope of the present invention is shown not by the embodiment but by the claims. Various modifications made within the scope of the claims and the equivalents of the invention are considered to be within the scope of the present invention.

  INDUSTRIAL APPLICATION This invention can be employ | adopted suitably for a cooking system.

  DESCRIPTION OF REFERENCE NUMERALS 1 focus detection system, 2, 2A, 2B cooking utensil, 3 heating cooker, 4 cooked food, 5 odor sensor, 6 camera, 20 impedance measuring device, 21a, 21-1a to 21-3a, 21b, 21-1b 21-3b electrode, 22 mark, 23 focus detection device, 24, 36 temperature sensor, 30 housing, 31 top plate, 32 operation receiving unit, 33 heating coil, 34 inverter circuit, 35, 201, 231 communication unit, 37, 202, 232 control unit, 38, 200, 200-1 to 200-3, 230 measurement circuit, 203 electrode switching unit, 210 oscillator, 211 voltage sensor, 212 current sensor, 310a, 310b conductor, 320 power button, 321 Touch panel, 370 CPU, 371 ROM, 372 RAM, 373 secondary storage device 374 port, 375 bus, 3700 impedance acquisition unit, 3701 a temperature acquiring unit, 3702 focus with the detection unit, 3703 a heating reduction unit, 3704 notification unit

Claims (10)

Heating means for heating the food;
Impedance measuring means for measuring the impedance of the food,
Temperature measuring means for measuring the temperature of the food,
Detection means for detecting the sticking of the food based on the measured impedance and a threshold determined according to the measured temperature,
An informing unit that informs a user that the in-focus has been detected. It said sensing means, impedance the measured senses the scorching said if it exceeds the previous Ki閾 value, focus with the detection system according to claim 1.   The focus detection system according to claim 1, wherein the threshold value is a value obtained by subtracting a correction value obtained by multiplying the measured temperature by a predetermined coefficient from a predetermined reference threshold value. Cooking utensil comprising the impedance measuring means,
The heating unit, the temperature measurement unit, the detection unit, and a heating cooker including the notification unit,
The cooking appliance further includes a transmission unit that transmits a measurement result of the impedance measurement unit to the cooking device,
The focus detection system according to any one of claims 1 to 3, wherein the heating cooker further includes a receiving unit that receives the measurement result from the cooking appliance. The impedance measuring means, a cooking appliance including the temperature measuring means,
The heating means, the detection means, and a heating cooker including the notification means,
The cooking appliance further includes a transmission unit that transmits a measurement result of the impedance measurement unit and the temperature measurement unit to the heating cooker,
The focus detection system according to any one of claims 1 to 3, wherein the heating cooker further includes a receiving unit that receives the measurement result from the cooking appliance.   6. The focus detection system according to claim 4, wherein the heating cooker further includes a heating reducing unit configured to stop or reduce heating of the food by the heating unit when the focus is detected. 7. Further comprising an odor measuring means for measuring odor,
The focus detection system according to any one of claims 4 to 6, wherein the detection means of the heating cooker detects the focus of the cooked food in consideration of a measurement result of the odor measurement means. An imaging unit for imaging the food is further provided,
The focus detection system according to any one of claims 4 to 7, wherein the detection means of the heating cooker detects the focus of the cooked food in consideration of an image taken by the imaging means. Communication means for communicating with the cooking device;
Impedance measuring means for measuring the impedance of the food;
Temperature measuring means for measuring the temperature of the food,
Detection means for detecting the sticking of the food based on the measured impedance and a threshold determined according to the measured temperature,
Notifying means for notifying the heating cooker that the burning is detected. Impedance measuring means measures the impedance of the food,
Temperature measuring means measures the temperature of the food,
Detection means detects the scorching of the food based on the measured impedance and a threshold determined according to the measured temperature,
A focus detection method, wherein a notification unit notifies the user that the focus has been detected.

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