EP4050971A1

EP4050971A1 - Heating cooker

Info

Publication number: EP4050971A1
Application number: EP21192056.6A
Authority: EP
Inventors: Masafumi Sadahira; Tomoya Fujinami; Zarina Rafii; Satoshi Furusawa
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2021-02-25
Filing date: 2021-08-19
Publication date: 2022-08-31
Also published as: CN114980392A; JP2022129880A

Abstract

A heating cooker comprises: a placement unit on which a container is placed; one or more heating units arranged below the placement unit, for heating the container; an infrared sensor disposed substantially above the one or more heating units, the infrared sensor having a plurality of pixels that detect temperatures above the placement unit for the container as temperature information; a container size measurement unit measuring size of the container, based on the temperature information; and a heating control unit controlling heating energy applied to the container by each of the one or more heating units, based on the size of the container.

Description

TECHNICAL FIELD

The present disclosure relates to a heating cooker.

BACKGROUND ART

Conventionally, a heating cooker has been known that prevents boiling over by the strength of the heating power.
For example, JP 2014-234929 A describes a heating cooker including a heating unit, a temperature sensor detecting the temperature of a container or of object to be cooked in the container, a heating power change instruction unit instructing to change the heating power of the heating unit, and a cooking control unit. The cooking control is configured to switch the heating power of the heating unit between first heating power and second heating power less than the first heating power and, when instructed to change the heating power of the heating unit from the heating power change instruction unit, change only the first heating power, of the first heating power and the second heating power.

Citation List

Patent Literature

PLT 1: JP 2014-234929 A

SUMMARY OF INVENTION

TECHNICAL PROBLEM

The heating cooker described in JP 2014-234929 A controls boiling noodles and preventing boiling over through switching the strength of the heating power. However, the heating cooker switches the heating power without taking into consideration the size of the container to be heated, and therefore may undergo boiling over when heating a small container. On the contrary, when a large container is heated, water may not boil sufficiently due to insufficient heating. Such a case, convection of water in the container cannot be secured and noodles as object to be cooked do not move through the water, with the result that insufficient boiling may occur such as not being heated evenly.

SOLUTION TO PROBLEM

An object of the present disclosure is to provide a heating cooker capable of both securing convection of object to be cooked and preventing boiling over, irrespective of the size of a container to be heated.
The heating cooker of the present disclosure comprises: a placement unit on which a container is placed; one or more heating units arranged below the placement unit, for heating the container; an infrared sensor that is disposed substantially above the one or more heating units, the infrared sensor having a plurality of pixels that detect temperatures above the placement unit for the container as temperature information; a container size measurement unit that measures size of the container, based on the temperature information; and a heating control unit that controls heating energy applied to the container by each of the one or more heating units, based on the size of the container.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present disclosure, the heating cooker can be provided that is capable of both securing convection of object to be cooked and preventing boiling over, irrespective of the size of the container to be heated.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 is a view showing a schematic configuration of a heating cooker according to an embodiment.
Fig. 2 is a lateral view showing a schematic configuration of the heating cooker according to the embodiment.
Fig. 3 is a block diagram showing communication connections of the heating cooker according to the embodiment.
Fig. 4 is a flowchart showing a heating control process effected by the heating cooker according to the embodiment.
Fig. 5 is a view showing an example of a part of a field of view region being detected by an infrared sensor of the heating cooker according to the embodiment.
Fig. 6 is a view showing temperatures detected in the field of view region shown in Fig. 5.
Fig. 7 is a graph showing an example of temperature variation in temperatures detected by the infrared sensor of the heating cooker according to the embodiment.
Fig. 8 is a graph showing an example of output of a heating coil of the heating cooker according to the embodiment.
Fig. 9 is a schematic view showing dimensions for use in correction of the size of a container.
Fig. 10 is a block diagram showing a configuration of a terminal according to the embodiment.
Fig. 11 is a view showing an example of a mounting position input program displayed on the terminal.

DESCRIPTION OF EMBODIMENTS

Embodiments according to the present disclosure will now be described with reference to the drawings. It is to be noted, however, that configurations described below are mere examples of the present disclosure, that the present disclosure is not limited to the embodiments below, and that, various modifications other than these embodiments can be made depending on designs, etc. without departing from technical ideas of the present disclosure.

Embodiment

Fig. 1 is a view showing a schematic configuration of a heating cooker 1 according to an embodiment of the present disclosure. Fig. 2 is a schematic lateral view of the heating cooker 1 viewed from the lateral side. In Figs. 1 and 2, a container (pot) 2 is placed on the heating cooker 1. The container 2 holds an object 3 to be cooked as a cooking subject. Hereinafter, referring basically to Fig. 1, a configuration of the heating cooker 1 according to the embodiment of the present disclosure will be described. In Fig. 1, an X-axis direction indicates a longitudinal direction of the heating cooker 1, a Y-axis direction indicates a front-to-back direction, and a z-direction indicates a height direction. A positive direction of an X-axis is the right side and a negative direction thereof is the left side. A positive direction of a Y-axis is the back side and a negative direction thereof is the front side.
When heating a container containing a water-rich food such as noodles to be cooked, the heating cooker 1 according to the present disclosure is capable of preventing the object to be cooked from boiling over while securing occurrence of convection in the object to be cooked. The boil-over phenomenon occurs partly due to volume expansion caused by a film that is formed on the water surface from starch etc. eluted from the object to be cooked so that air bubbles generated at the bottom of the heated container become hard to disappear on the water surface. If heating power is simply weakened to suppress the boil-over phenomenon, boil of the object to be cooked in the container and generation of air bubbles are suppressed, making it hard for convection in the object to be cooked to occur, which may result in underheating of the object to be cooked. Accordingly, in order to prevent boiling over of the object to be cooked, it is important to control generation of air bubbles by controlling heating energy applied to the container based on the size of the container, instead of simply strengthening or weakening the heating power to heat the container. It is also important to control generation of air bubbles from the bottom of the container in consideration of the energy density of the heating energy applied to the bottom of the container by heating. The heating cooker according to the present disclosure controls generation of air bubbles at the bottom of the container by controlling the heating energy applied to the bottom of the container based on the size of the container, thereby simultaneously achieving both securing convection in the object to be cooked arising from boil of the object to be cooked and preventing the object to be cooked from boiling over.
As shown in Fig. 1, the heating cooker 1 comprises a main body 4, a top plate 5, heating coils 6A to 6C, an infrared sensor 7, a communication circuit 8, an operation panel 9, and a control device 20.
The main body 4 includes in its interior the heating coils 6A to 6C and the control device 20. The main body 4 has a top surface on which the top plate 5 is disposed and a lateral surface on which the operation panel 9 is disposed.
The top plate 5 is a placement unit on top of which the container 2 can be placed. The top plate 5 is disposed on the top surface of the main body 4. The top plate 5 is made of a material such as e.g. glass that can transmit magnetic fields generated by the heating coils 6A to 6C.
The heating coils 6A to 6C are heating units heating the container 2 that are arranged below the top plate 5. The heating coils 6A to 6C generate induced magnetic fields when supplied with high-frequency current. By the magnetic fields, the heating coils 6A to 6C apply heat to a bottom surface, etc. of the container 2 placed on the top plate 5, whereby the object 3 to be cooked held in the container 2 can be heated.
As shown in Fig. 1, arrangement of the three heating coils 6A to 6C enables the heating cooker 1 to simultaneously heat and cook three pieces of object 3 to be cooked. Fig. 1 shows an example in which one container 2 holding the object 3 to be cooked is placed over the heating coil 6A.
The infrared sensor 7 is a temperature detection unit that detects infrared rays emitted from the object 3 to be cooked in the container 2 to thereby detect the temperature of the object 3 to be cooked as temperature information from above based on the infrared rays. The infrared sensor 7 may be e.g. an infrared camera, a thermal image camera, etc. Similarly, the infrared sensor 7 detects infrared rays radiated from the top plate 5 to thereby detect the temperature of the top plate 5 as temperature information. Hereinafter, "the infrared sensor 7 detects infrared rays emitted from an object to thereby detect the temperature of the object based on the infrared rays" is referred to simply as "the infrared sensor 7 detects the temperature of the object". The infrared sensor 7 is disposed substantially above the top plate 5 so that it can detect the object 3 to be cooked and the top plate 5 from above. The infrared sensor 7 is connected to the communication circuit 8 to output the acquired temperature information to the communication circuit 8.
In this embodiment, the infrared sensor 7 has a field of view region that is divided into e.g. a plurality of grid-like regions (e.g. 32×32=1024 regions). Each region is a temperature detected region whose temperature is detected by infrared detection elements (i.e. pixels). The field of view region of the infrared sensor 7 may be divided into other regions.
The communication circuit 8 is an interface device that transmits the temperature information detected by the infrared sensor 7, via a communication line wiredly or wirelessly, to a communication circuit 22 that is one of components of the control device 20.
The operation panel 9 is an input device for working the heating cooker 1. The operation panel 9 is disposed on a front lateral surface of the main body 4. The user of the heating cooker 1 operates the operation panel 9 to use the heating cooker 1. Input information from the operation panel 9 is output to and processed by a control circuit 21 of the control device 20. The operation panel 9 may comprise a display 10 that displays information required to use the heating cooker 1 such as power on/off of the heating cooker 1 and output (i.e. heating power) of the heating coils 6A to 6C. The operation panel 9 comprises an operation input unit 11 so as to allow e.g. a predetermined mode to work. The heating cooker 1 has at least a mode for applying heat to boil noodles, etc. and automatically controlling the heating power to prevent boiling over caused by heating. For example, the heating cooker 1 may have a mode for controlling the heating coils 6A to 6C to emit proper heating powers depending on dishes.
The heating cooker 1 according to this embodiment comprises: a plurality of operation input units 12A to 12C for the user to operate the heating coils 6A to 6C, respectively; and a display unit 13. The display unit 13 is disposed on the front side of the top plate 5 of the heating cooker 1 and displays outputs of the heating coils 6A to 6C. The operation input units 12A to 12C are arranged in front of the display unit 13 on the top plate 5 of the heating cooker 1. The user operates the operation input units 12A to 12C to control e.g. the outputs of the heating coils 6A to 6C. The operation input unit 12A and the heating coil 6A correspond to each other, the operation input unit 12B and the heating coil 6B correspond to each other, and the operation input unit 12C and the heating coil 6C correspond to each other. In response to an operation instruction of the operation input unit 12A, a heating control unit 24 described later controls start and stop of heating of the heating coil 6A. The operation input units 11 and 12A to 12C may be physical buttons or a touch panel.
As described above, the container 2 is placed on the top plate 5. The container 2 holds the object 3 to be cooked that is a cooking subject to be heated and cooked. The container 2 is heated by any one of the heating coils 6A to 6C arranged below the top plate 5. The container 2 may be made of e.g. a metal material such as iron, stainless steel, aluminum, copper, etc.
As shown in Fig. 2, the infrared sensor 7 can detect infrared rays having an energy E1 in accordance with the emissivity of the object 3 to be cooked that are radiated from the object 3 to be cooked in the container 2. Accordingly, the control circuit 21 described later of the heating cooker 1 can provide heating control, based on the temperature detected from the object 3 to be cooked.
Fig. 3 is a block diagram showing communication connections of the above components and the control circuit 21 of the control device 20.
As described above, the infrared sensor 7 is connected to the communication circuit 8. The communication circuit 8 is connected to the communication circuit 22 of the control device 20 housed in the main body 4. The control circuit 21 is connected to the communication circuit 22 and acquires, via the communication circuits 8 and 22, the temperature information detected by the infrared sensor 7.
The control device 20 comprises the control circuit 21, the communication circuit 22, and a storage device 23.
The control circuit 21 is a computer and comprises the heating control unit 24, a container size measurement unit 25, and a cooking status determination unit 26. As described later, the control circuit 21 may comprise a mounting position determination unit and a container size correction unit. The control circuit 21 includes a general purpose processor such as CPU or MPU that runs a program to achieve predetermined functions. For example, the control circuit 21 calls and runs an arithmetic program, etc. stored in the storage unit 23, to thereby implement various processes of the control device 20 such as a heating process of the heating control unit 24 and a measuring process of the container size measurement unit 25. The control circuit 21 is not limited to the mode in which hardware and software cooperate to achieve predetermined functions. The control circuit 21 may be a hardware circuit designed dedicatedly to achieve the predetermined functions. That is, the control circuit 21 may be implemented by various processors such as GPU, FPGA, DSP, ASIC, etc. other than CPU and MPU. Such a control circuit 21 may be composed of e.g. a signal processing circuit that is a semiconductor integrated circuit. The hardware configuration of the control circuit 21 applies to hardware configurations of the heating control unit 24, the container size measurement unit 25, the cooking status determination unit 26, the mounting position determination unit, and the container size correction unit.
The heating control unit 24 controls e.g. the magnitude of current flowing through the heating coils 6A to 6C, the time during which the current flows therethrough, etc. to thereby control at least one of the heating output and the heating time imparted from the heating coils 6A to 6C to the container 2 and the object 3 to be cooked. The heating control unit 24 may be configured to start the above control when the cooking status determination unit 26 determines that predetermined conditions have been reached. For example, the heating control unit 24 sets the outputs of the heating coils 6A to 6C to any one of a plurality of predefined power stages, to control the outputs. The heating control unit 24 may set the plurality of power stages with electric energy such as 2,000W, 1,450W, 1,000W, 700W, etc. or with relative output such as "strong", "medium", "weak", or "1" to "9", etc. The heating control unit 24 may be configured to allow continuous change and control. The control circuit 21 may display, on the operation panel 9 or on the display unit 13, the outputs of the heating coils 6A to 6C set by the heating control unit 24. The heating control unit 24 can control the outputs and heating times of the heating coils 6A to 6C, based on instructions input via the operation input units 11 and 12A to 12C.
The container size measurement unit 25 measures the size of the container 2 heated by each of the heating coils 6A to 6C, from temperature information based on the temperature detected by the infrared sensor 7. For example, the container size measurement unit 25 sets a predetermined threshold value to regard as the container 2 a region including pixels from which temperatures higher than the threshold value are detected. The container size measurement unit 25 measures the area of the container 2, based on the number of such pixels. For example, the container size measurement unit 25 may measure the size of the container 2, based on whether the detected temperatures exceed the threshold value after the lapse of a predetermined period of time from the start of heating by the heating coils 6A to 6C. The container size measurement unit 25 may be configured to measure the container size when one of the temperatures detected by the infrared sensor 7 exceeds another threshold value that is set to a temperature higher than the above threshold value.
As described in detail later, the cooking status determination unit 26 determines whether the object 3 to be cooked in the container 2 has reached a predetermined cooking status, from the temperature information based on the temperatures detected by the infrared sensor 7. The predetermined cooking status includes e.g. boiling of the object 3 to be cooked and putting foodstuff into the container 2. When the cooking status determination unit 26 determines that the above cooking status has been reached, it outputs the information to the heating control unit 24.
The communication circuit 22 is disposed inside the main body 4 and below the top plate 5 and is connected to the control circuit 21. The communication circuit 22 receives from the communication circuit 8 temperature information acquired by the infrared sensor 7 and outputs it to the control circuit 21.
Similar to the communication circuit 8, the communication circuit 22 is an interface device that receives the temperature information from the communication circuit 8 via the communication line wiredly or wirelessly. The communication circuits 8 and 22 may be connectable to other devices by way of communication lines. The interface device is capable of performing communication compliant with wired communication standards for e.g. USB, Ethernet, etc. The interface device is capable of performing communication compliant with wireless communication standards for e.g. Wi-Fi, Bluetooth, mobile phone line, etc.
The storage device 23 is a storage medium capable of storing various pieces of information. The storage device 23 stores the temperature information received by the communication circuit 22 so that the control circuit 21 can utilize the information stored. The storage device 23 is implemented by e.g. a memory such as DRAM, SRAM, flash memory, etc., HDD, SSD, or other storage device, or a proper combination thereof. As already described above, the storage device 23 stores therein a program for implementing various processes effected by the control circuit 21 of the control device 20. The storage device 23 can store outputs of the heating coils 6A to 6C, heating times at the outputs, temperatures detected by the infrared sensor 7, etc. As described later, the storage device 23 may store a table indicative of relationships between any pieces of information, such as e.g. a table indicative of relationships between the measured size of the container 2 and the capacity of water held in the container 2. As described later, the storage device 23 may store an arithmetic program for calculating the relationships between any pieces of information, such as e.g. an arithmetic program for calculating the above capacity of water from the above measured size of the container 2.
Fig. 4 is a flowchart showing a heating control process effected by the control circuit 21 of the heating cooker 1 according to this embodiment. First, the control circuit 21 causes current to flow through the heating coil 6A by the heating control unit 24, to heat the container 2 (S1). Next, the control circuit 21 acquires as temperature information the temperature detected by the infrared sensor 7 (S2) and measures the size of the container 2 by the container size measurement unit 25 (S3).
After measuring the size of the container 2, the control circuit 21 allows the heating control unit 24 to determine heating energy applied to the container, based on the size of the container 2 (S4). When the control circuit 21 determines that the heated state in the container 2 has reached a predetermined state (S5), the control circuit 21 allows the heating control unit 24 to start heating control so as to keep the determined heating energy within a predetermined range (S6).
The heating cooker 1 according to this embodiment provides heating control as described above when heating the container 2 so as to keep the heating energy determined based on the size of the container 2, to consequently prevent boiling over caused by heating.
Fig. 5 shows an example of a part of the field of view region detected by the infrared sensor 7 of the heating cooker 1 according to this embodiment. Fig. 6 shows an example of temperatures detected by the infrared sensor 7 in the field of view region shown in Fig. 5. The temperatures shown in Fig. 6 are temperatures detected from the container 2 being heated by the heating coil 6A. The control circuit 21 measures the container size from temperature information on the temperatures by the container size measurement unit 25. For example, in this embodiment, the container size measurement unit 25 determines a pixel whose temperature detected by the infrared sensor 7 is equal to or above 80 degrees centigrade as forming a region of the container 2. Thus, the control circuit 21 determines a region T1 indicated in Fig. 6 as the size of the container 2 by the container size measurement unit 25. Since as shown in Fig. 6 the infrared sensor 7 can detect temperatures of a region corresponding to the object 3 to be cooked in the container 2 in accordance with the heated state of the object 3 to be cooked, the control circuit 21 can determine pixels of the region corresponding to the container 2 by the container size measurement unit 25.
Based on the pixels determined as forming the region of the container 2, the control circuit 21 measures the size of the container 2 by the container size measurement unit 25. For example, a table indicative of relationships between the number of pixels and the area of the container 2 is stored in the storage device 23. The control circuit 21 may refer to the table to measure the area of the container 2 from the number of pixels determined as forming the region of the container 2. Note that the position in the height direction mounted with the infrared sensor 7 is already known and that the average container height can also be predetermined. The above table can be created by finding in advance the relationships between the number of pixels of the container and the area of the container 2 when shot under these conditions.
Fig. 7 is a graph showing an example of temperature variation in temperatures detected by the infrared sensor 7 of the heating cooker 1 according to this embodiment. The above temperature is a mean value of temperatures of at least a partial region in the container 2. As shown in the graph of Fig. 7, when the control circuit 21 allows the heating coil 6A to heat the container 2, the temperature detected by the infrared sensor 7 rises. In the case where the object 3 to be cooked held in the container 2 contains a lot of water, the temperature rise of object 3 to be cooked saturates at about 100 degrees centigrade. Accordingly, when the cooking status determination unit 26 detects a temperature saturation from outputs of the infrared sensor 7, the control circuit 21 can presume that water contained in the object 3 to be cooked is boiling. Since the temperatures detected by the infrared sensor 7 may have some error with respect to the actual temperatures, the temperature saturation detected by the infrared sensor 7 may occur at temperatures other than 100 degrees centigrade.
In the graph shown in Fig. 7, the timing indicated by an arrow A is a timing at which the saturation in temperature rise has been detected. When detecting the temperature rise saturation, the control circuit 21 may start the heating control process for boil-over prevention by the heating control unit 24. By performing the heating control process for boil-over prevention, the infrared sensor 7 can acquire a temperature waveform in which rise and fall of the temperature are repeated after the temperature rise saturation, as shown subsequently to the timing indicated by the arrow A.
The control circuit 21 may start the heating control process at another timing. An example of the another timing is a timing at which foodstuff is put into the container 2. In the graph shown in Fig. 7, at the timing indicated by an arrow B, a temporary, sudden drop in temperature is detected. The control circuit 21 detects as the temperature variation an overall drop in temperature of the object 3 to be cooked which is caused by putting foodstuff having a temperature lower than that of water into water that has reached its boiling point. For example, the control circuit 21 may determine that foodstuff has been put in when the cooking status determination unit 26 detects a temporary drop in temperature that is larger than a predetermined threshold value. The cooking status determination unit 26 may set any value such as e.g. 20 degrees centigrade, 30 degrees centigrade, etc. as the predetermined threshold value.
The control circuit 21 of the heating cooker 1 according to this embodiment controls heat application to the container 2 by switching the output of the heating coil 6A at a predetermined cycle between a first heating energy for applying a greater energy to the container 2 and a second heating energy that is smaller than the first heating energy. Fig. 8 is a graph showing an example of the output of the heating coil 6A, set by the heating control unit 24. As shown in Fig. 8, the peak value of the output of the heating coil 6A having the first heating energy indicated by an arrow C is 1,450 W. The peak value of the output of the heating coil 6A having the second heating energy indicated by an arrow D is 1,000 W. The predetermined cycle T means a certain interval indicated by an arrow E of Fig. 8 when the outputs of the heating coils 6A to 6C are varied repeatedly between the predetermined peak values at the certain interval.
Referring to Fig. 8, description will be given of Example of heating control provided by the heating cooker 1 according to this embodiment. In Example shown in Fig. 8, the control circuit 21 switches the output of the heating coil 6A between the first heating energy and the second heating energy every 50 % of the cycle by the heating control unit 24. The heating time of the first heating energy and the heating time of the second heating energy need not be the same, and hence the control circuit 21 may switch the heating time of each heating energy at any ratio. The heating cooker 1 according to this Example can operate the heating coils 6A to 6C with outputs having peak values of at least any of 500 W, 700 W, 1,000 W, 1,450 W, 2,000 W, and 2,500 W through the heating control for boil-over prevention, but this is not limitative.
In this Example, the control circuit 21 performs the heating control process for boil-over prevention for a first container having a diameter of 18 cm at the output of the heating coil 6A shown in Fig. 8. When the first container is heated at the output of 1,450 W, the object 3 to be cooked held in the first container boils violently and air bubbles generated at the bottom of the first container create convection inside the object 3 to be cooked. Although in this Example, the object 3 to be cooked is water and noodles, the present disclosure is not limited thereto. In this Example, the first container holds the object 3 to be cooked so that the water level is about 60% of the height of the first container. About 1000 g of water is held in the first container to reach the above water level. The noodles being boiled in the first container move through the water along the flow of convection to be heated evenly. When heated at the output of 1,450 W for a certain period of time or more, the object 3 to be cooked becomes bubbled due to air bubbles generated in the object 3 to be cooked by boiling, with the result that boiling over may occur with the increased bubbles on the object 3 to be cooked. For this reason, in this Example, boiling over is prevented by heating at the output of 1,450 W for a predetermined period of time as described above and thereafter switching the output to 1,000 W lower than 1,450 W. In this Example, the output is switched to 1,000 W after heating with 1,450 W for about 8 seconds.
When the first container is heated at the output of 1,000 W, the object 3 to be cooked boils gently as compared with the case of heating at the output of 1,450 W. This suppresses the generation of air bubbles inside the object 3 to be cooked from the bottom of the first container and therefore bubbling at the surface of the object 3 to be cooked, whereupon the amount of bubbles, which has increased by heating at the output of 1,450 W, decreases. Since the amount of bubbles decreases when heated at the output of 1,000 W, the heating cooker 1 can prevent boiling over.
When heated at the output of 1,000 W, however, the convection flow generated in the object 3 to be cooked is weak, so that noodles do not move by convection as much as when heated at the output of 1,450 W. Accordingly, if heating continues at the output of 1,000 W, uneven heating may occur in which only a part of the noodles is heated. Thus, when the amount of bubbles generated by heating at the output of 1,450 W decreases as a result of heating at the output of 1,000 W for a predetermined period of time, the control circuit 21 of the heating cooker 1 switches the output to 1,450 W to effectively heat the object 3 to be cooked. In this Example, switching to 1,450 W occurs when heated at the output of 1,000 W for about 8 seconds.
As described hereinabove, the heating cooker 1 according to this embodiment controls heat application to the container 2 by switching the output of the heating coil 6A at predetermined periods of time between a first heating energy for applying a greater energy to the container 2 and a second heating energy that is smaller than the first heating energy. By providing such heating control, the heating cooker 1 can convect and effectively heat the object 3 to be cooked while preventing the object 3 to be cooked from boiling over.
In the case where the output used in the above Example is applied to the container 2 having a different size, it may be difficult unlike the Example to simultaneously achieve both effective heating ensuring occurrence of convection of the object 3 to be cooked and prevention of boiling over. For example, if the container 2 has a diameter larger than 18 cm of Example, the object 3 to be cooked may not be heated sufficiently at the output of 1,450 W and the above convection may not occur. If the container 2 has a diameter smaller than 18 cm, when heated at the output of 1,450 W, so many bubbles are generated and boiling over may occur immediately. Furthermore, even if heated at the output of 1,000 W, the generation of air bubbles in the object 3 to be cooked may not be suppressed, which may result in generation of a lot of bubbles and occurrence of boiling over.
For this reason, the control circuit 21 of the heating cooker 1 according to the present disclosure measures the size of the container 2 and changes the peak values of the outputs of the heating coils 6A to 6C, based on the size measured. The control circuit 21 thereby changes the heating energy applied to the container 2 so that the heating energy applied to the container 2 has an equal energy density. The energy density means heating energy per unit area and unit time applied to the container 2. The control circuit 21 can provide the heating control at proper outputs by changing the heating energies applied to the object 3 to be cooked by heating the container 2 with the heating coils 6A to 6C. Thus, according as the container size increases, the control circuit 21 increases the heating energy applied to the container 2. On the contrary, the smaller the size of the container 2, the smaller the heating energy applied to the container 2.
For example, in the case of providing the heating control for boil-over prevention for a second container having a diameter of 22 cm, the area of the second container is 121 πcm². On the other hand, the first container of 18 cm in diameter has an area of 81 πcm². In consequence, the area of the second container has a size of about 149% of the area of the first container. Using the heating control unit 24, the control circuit 21 figures out the output of the heating coil 6A having the same energy density as that of the first heating energy applied to the first container to be 2,160 W, based on the difference of size between the containers. As described above, the heating cooker 1 according to this Example can operate the heating coil 6A at any one of the predetermined outputs. Thus, via the heating control unit 24, the control circuit 21 selects the output of 2,000 W closer to 2,160 W as being the first heating energy, to heat the second container.
Similarly, via the heating control unit 24, the control circuit 21 figures out the output of the heating coil 6A having the same energy density as that of the second heating energy applied to the first container to be 1,490 W. Therefore, via the heating control unit 24, the control circuit 21 selects the output of 1,450 W closer to 1,490 W as being the second heating energy, to heat the second container.
In the case of providing the heating control for boil-over prevention for a third container having a diameter of 14 cm, the area of the third container is 49 πcm². In consequence, the area of the third container has a size of about 60% of the area of the first container. In the same manner as in the above, via the heating control unit 24, the control circuit 21 figures out the output of the heating coil 6A having the same energy density as that of the first heating energy applied to the first container to be 870 W. Thus, via the heating control unit 24, the control circuit 21 selects the output of 1,000 W closer to 870 W as being the first heating energy, to heat the third container.
Similarly, via the heating control unit 24, the control circuit 21 figures out the output of the heating coil 6A having the same energy density as that of the second heating energy applied to the first container to be 600 W. Therefore, via the heating control unit 24, the control circuit 21 selects the output of 700 W closer to 600 W as being the second heating energy, to heat the third container.
By changing the peak values of the outputs of the heating coils 6A to 6C in this manner, the heating cooker 1 according to this embodiment can vary the energy density of the heating energy applied to the container 2, based on the size of the container 2. By adjusting the heating energy, the control circuit 21 can control the energy densities of the heating energy applied to the container 2 from the heating coils 6A to 6C so as to be within a predetermined range as described later irrespective of the size of the container. As a result, at proper outputs in accordance with the size of the container 2, the heating cooker 1 can convect and effectively heat the object 3 to be cooked while preventing the object 3 to be cooked from boiling over due to heating.
If the above second and third containers hold the object 3 to be cooked so that the water level is about 60% of the height of the respective containers similarly to the first container, about 2,250 g of water is held in the second container and about 650 g of water is held in the third container. As described above, by controlling the outputs of the heating coils 6A to 6C based on the size of each container, heating energy having the same energy density as that of the heating energy applied to the first container is applied to the second and third containers. Accordingly, the heating cooker 1 according to this embodiment can provide the heating control process for boil-over prevention by varying the cycle of period of time during which heating energy is applied, depending on the volume (i.e. capacity) of the object 3 to be cooked to which the heating energy is applied.
The capacity of water held in the second container is about 225 % of that of water held in the first container. In the heating control for the first container, the heating time at the first heating energy and the heating time at the second heating energy are each 8 seconds. The heating control unit 24 switches the heating energy at the cycle of 16 seconds. Hence, if the second container is heated with the heating energy switched about every 18 seconds at the cycle of 36 seconds, heating control similar to the heating control for the first container can be provided. Heating need not be performed for the calculated period of time. For example, since the capacity of water held in the second container is about twice that of water held in the first container, the control circuit 21 may control the heating coils 6A to 6C to switch their respective heating energies at the cycle of 32 seconds. By providing such heating control, the heating cooker 1 can convect and effectively heat the object 3 to be cooked while preventing the object 3 to be cooked from boiling over, similarly to the case of the heating control for the first container.
The capacity of water held in the third container is about 62 % of that of water held in the first container. As described above, in the heating control for the first container, the heating time at the first heating energy and the heating time at the second heating energy are each 8 seconds. The heating control unit 24 switches the heating energy at the cycle of 16 seconds. Hence, if the third container is heated with the heating energy switched about every 5 seconds at the cycle of 10 seconds, heating control similar to the heating control for the first container can be provided. As described above, for example, since the capacity of water held in the third container is about half of that of water held in the first container, the control circuit 21 may control the heating coils 6A to 6C to switch their respective heating energies at the cycle of 8 seconds. By providing such heating control, the heating cooker 1 can convect and effectively heat the object 3 to be cooked while preventing the object 3 to be cooked from boiling over, similarly to the case of the heating control for the first container.
The capacity of the object 3 to be cooked held in the container 2 can be inferred from e.g. the temperature information on temperatures detected by infrared sensor 7. The control circuit 21 may detect the water level in the container 2 and the height of the container lateral surface from the acquired temperature information and combine the water level information and the area of the container 2 to calculate the capacity. The storage device 23 may store therein combinations of the sizes of the container 2 and the capacities of the object to be cooked at those sizes. By doing so, when detecting the size of the container 2, the control circuit 21 can select the capacity of the object 3 to be cooked held in the container 2 and calculate the heating time based on the selected capacity to control the heating times of the heating coils 6A to 6C. Furthermore, the capacity of the object 3 to be cooked can be calculated and inferred from the outputs of the heating coils 6A to 6C and the temperature variations in the acquired temperature information.
The storage device 23 may store therein combinations of the container sizes and the heating time cycles at those sizes. By doing so, when detecting the container size, the control circuit 21 can select the cycle based on the size and control the heating time cycles of the heating coils 6A to 6C. As described above, since according as the size of the container 2 goes up the capacity of the object 3 to be cooked held in the container 2 increases, the control circuit 21 elongates the cycle. On the contrary, since according as the size of the container 2 goes down the capacity of the object 3 to be cooked held in the container 2 decreases, the control circuit 21 shortens the cycle.
In this manner, the heating cooker 1 according to this embodiment can change the heating times by changing the cycles, in addition to being able to change the output peak values of the heating coils 6A to 6C, based on the size of the container 2 or on the capacity of the object 3 to be cooked held in the container 2. As a result, the heating cooker 1 controls the generation of air bubbles at the bottom of the container 2 with proper outputs and heating times in accordance with the size of the container 2, thereby making it possible to prevent the object 3 to be cooked from boiling over while performing effective heating ensuring the occurrence of convection of the object 3 to be cooked.
In the above Example, the outputs of the heating coils 6A to 6C are configured to be able to apply heat with predetermined outputs, but the present disclosure is not limited thereto. For example, the control circuit 21 may be configured to be able to continuously change the outputs of the heating coils 6A to 6C through the heating control unit 24. By being configured in this manner, the control circuit 21 can heat the container with heating energy having a more proper energy density, based on the container size.
In the above Example, based on the capacity of water held in the first container as a reference and on the heating time for that capacity, the heating time for the capacity of water held in anther container is calculated so that the outputs of the heating coils 6A to 6C are switched at that heating time, but the present disclosure is not limited thereto. For example, the storage device 23 may store therein a table indicative of relationships between the size of the container 2 and the capacity of water, while the control circuit 21 may acquire the capacity of water by measuring the size of the container 2 and referring to that table.
The first heating energies applied to the first container, the second container, and the third container described in the above Example have energy densities of about 5.70, about 5.92, and about 6.50 W/cm², respectively. The second heating energies applied to the first container, the second container, and the third container described in the above Example have energy densities of about 3.93, about 3.82, and about 4.55 W/cm², respectively.
Accordingly, when applying heating energy having at least the above energy density of the first heating energy to the container 2, the heating coils 6A to 6C can apply thereto heating energy allowing occurrence of convection of the object 3 to be cooked held in the container 2. When applying heating energy having at least the above energy density of the second heating energy to the container 2, the heating coils 6A to 6C can apply thereto heating energy capable of heating the object 3 to be cooked while suppressing generation of bubbles at the surface of the object 3 to be cooked.
Therefore, via the heating control unit 24, the control circuit 21 may set as a reference energy density a predetermined value among the energy densities included in the above and may effect the heating control process so as to vary the energy density of the heating energy with respect to the reference energy density as the reference. The control circuit 21, via the heating control unit 24, may set heating energy having an energy density larger than the above reference energy density as the first heating energy and set heating energy having an energy density smaller than that as the second heating energy, to effect the heating control process. Consequently, the control circuit 21 can control the generation of air bubbles at the bottom of the container 2 and carry out the heating control process for preventing the object 3 to be cooked from boiling over while performing effective heating ensuring the occurrence of convection of the object 3 to be cooked.
As described above, the heating cooker 1 according to the present disclosure provides heating control by controlling the outputs of the heating coils 6A to 6C so that the energy density of the heating energy applied to the container 2 become a predetermined energy density, based on the size of the container 2. It is therefore important to properly measure the size of the container 2.
The heating cooker 1 according to this embodiment measures the size of the container 2, based on the temperatures detected by the infrared sensor 7. Since the infrared sensor 7 may be mounted at any location upon installing the heating cooker, the field of view region detected by the infrared sensor 7 varies depending on the position where the infrared sensor 7 is mounted. When the field of view region varies, the size of the container 2 also changes that is measured based on the temperatures detected by the infrared sensor 7 and on the pixels of the infrared sensor 7. Hence, to effect the heating control process with proper outputs, the control circuit 21 needs to correct the measured size of the container 2, based on the positional relationship between the infrared sensor 7 and the top plate 5.
Fig. 9 is a schematic view showing information on positional relationships required to correct the size of the container 2. Fig. 9 shows the top plate 5, the heating coils 6A and 6B, and the infrared sensor 7. Although the heating coil 6C is not shown for simplification, the size of the container 2 placed over the heating coil 6C may also need to be corrected in such a manner as described later.
The control circuit 21 of the control device 20 further comprises the container size correction unit in order to execute the above correction. The container size correction unit has a hardware configuration similar to that of the control circuit 21. The container size correction unit can correct the container size measured by the container size measurement unit 25, from the top plate 5 and a mounting position of a mounting unit of the infrared sensor 7 and a mounting angle of a movable unit of the mounting unit, which described later.
The infrared sensor 7 comprises the mounting unit for mounting the infrared sensor 7 substantially above the top plate 5. The mounting unit may be mounted e.g. to a wall surface of a kitchen in which the heating cooker 1 is arranged or to a part of a ventilator arranged substantially above the heating cooker 1. The field of view - region of the infrared sensor 7 needs to be adjusted depending on the position where the mounting unit is mounted. To this end, the mounting unit includes a movable unit having one or more axes for adjusting the imaging angle of the infrared sensor 7. For example, the movable unit is an angle adjustment mechanism such as a latch capable of adjusting the imaging angle of the infrared sensor 7 vertically and transversely.
A dimension X₀ shown in Fig. 9 indicates a difference of distance in X-axis direction between a midpoint between centers of the heating coils 6A and 6B and the center of the heating coil 6B. A dimension Y₀ indicates a difference of distance in Y-axis direction between a back end of the top plate 5 in the front-to-beck direction and the center of the heating coil 6B. The dimensions X₀ and Y₀ are dimensions determined by the model of the heating cooker 1.
A dimension X₁ indicates a difference of distance in X-axis direction between the midpoint between the respective centers of the heating coils 6A and 6B and the position where the infrared sensor 7 is mounted. A dimension Y₁ indicates a difference of distance in Y-axis direction between the back end of the top plate 5 in the front-to-beck direction and the position where the infrared sensor 7 is mounted. A dimension Z₁ indicates a difference of distance in Z-axis direction between the top surface of the top plate 5 and the position where the infrared sensor 7 is mounted.
By acquiring the above dimensions X₀, Y₀, X₁, Y₁, and Z₁, the control circuit 21 can determine the mounting angle of the mounting unit of the infrared sensor 7 by the mounting position determination unit. The control circuit 21 finds and determines as the mounting angle e.g. an angle θ_X that is an angle representative of the magnitude of the dimension X₁ relative to the dimension Z₁ and an angle θ_Z that is an angle representative of the magnitude of the sum of the dimension Y₀ and the dimension Y₁ relative to the dimension Z₁. For example, by adjusting the vertical angle and the transverse angle to be the angles θ_Z and θ_X, respectively, for the movable unit of the mounting unit of the infrared sensor 7, the infrared sensor 7 may be mounted at a mounting angle having a proper imaging angle.

Based on the acquired mounting position and on the determined mounting angle, the control circuit 21 corrects via the container size correction unit the container size measured by the container size measurement unit 25. For example, the storage device 23 may store therein a table showing relationships between the size of the container 2 measured by the container size measurement unit 25 when the infrared sensor 7 is mounted at predetermined mounting position and mounting angle and the actual size of the container 2. By storing this information, the control circuit 21 can calculate the rate to be corrected by the container size correction unit based on the mounting position and the mounting angle, to correct the container size. For example, Table 1 is an example of a table representing relationships of rates to be corrected relative to predetermined mounting positions and mounting angles.

TABLE 1

No.	X₀	Y₀	X₁	Y₁	Z₁	θ_X	θ_Z	Area Ratio (Left Side)	Area Ratio (Right Side)	Left-to-Right Ratio
1	152	315	0	116	600	0	35.7	1.00	1.00	1.00
2	152	315	0	116	800	0	28.3	0.67	0.67	1.00
3	152	315	0	54	600	0	31.6	1.10	1.10	1.00
4	152	315	-450	54	600	36.9	31.6	0.97	0.66	0.68
5	152	315	-450	54	800	29.4	24.8	0.66	0.50	0.76

The table shown as Table 1 is created by regarding the state where the infrared sensor 7 is mounted at the mounting position and the mounting angle shown with No. 1, as distances that do not require the size correction of the container 2. At the mounting position indicated in No. 2, the dimension Z₁ is changed from the mounting position shown in No. 1, with the result that the angle θ_Z is changed. The distance is calculated as being 754.2 between the infrared sensor 7 disposed at the mounting position shown with No. 1 in Table 1 and the center of the heating coil 6A. Since the infrared sensor 7 in No. 1 is disposed at the midpoint between the respective centers of the heating coils 6A and 6B in X-axis direction, the distance between the infrared sensor 7 and the center of the heating coil 6B is calculated similarly as being 754.2. The area of the heating coil 6A and the area of the heating coil 6B are therefore the same in magnitude. The left-to-right ratio represents the ratio of area of the heating coil 6B to the heating coil 6A. The sizes of the heating coils 6A and 6B mean the areas of ring marks (not shown) having the same sizes as those of the heating coils 6A to 6C, the ring mark being designated at positions corresponding to the heating coils 6A to 6C drawn on the top plate 5.
When the infrared sensor 7 is mounted at the mounting position indicated in No. 2, the distance between the infrared sensor 7 and the container 2 increases as compared with when the infrared sensor 7 is mounted at the mounting position indicated in No. 1. The distance between the infrared sensor 7 and the center of the heating coil 6A is figured out in the same manner as the above to be 921.3. As a result, the size of the container 2 measured by the control circuit 21 based on the temperatures detected by the infrared sensor 7 has a value of about 67 % of the size of the container 2 measured at the mounting position indicated in No. 1. The area ratio (left side) shown in Table 1 is a ratio of the area of the heating coil 6A measured by the infrared sensor 7 at the position indicated in No. 2, to the area of the heating coil 6A measured by the infrared sensor 7 at the position indicated in No. 1. The area ratio (right side) shown in Table 1 is a ratio of the area of the heating coil 6B measured by the infrared sensor 7 at the position indicated in No. 2, to the area of the heating coil 6B measured by the infrared sensor 7 at the position indicated in No. 1. Accordingly, in the case where the infrared sensor 7 is mounted at the mounting position indicated in No. 2, the container size correction unit corrects the size of the container 2 considering that the size of the container 2 measured by the container size measurement unit 25 is reduced to about 67 %. For example, correction can be made by deviding the measured container size by 0.67.
At the mounting position indicated in No. 4, the dimensions X₁ and Y₁ are changed from the mounting position indicated in No. 1, with the result that the angles θ_X and θ_Z are changed. At the mounting position indicated in No. 4, as shown in Table 1, the dimension X₁ is not 0 and the infrared sensor 7 is mounted at a position other than the midpoint between the respective centers of the heating coils 6A and 6B in X-axis direction. For this reason, the distance between the infrared sensor 7 and the heating coil 6A differs from the distance between the infrared sensor 7 and the heating coil 6B. In the case where the infrared sensor 7 is mounted at the position indicated in No. 4, the area ratio (left side) is 0.97 and the area ratio (right side) is 0.66. Hence, in the case where the infrared sensor 7 is not mounted at the midpoint between the respective centers of the heating coils 6A and 6B in X-axis direction in this manner, the heating coils 6A and 6B need to undergo different corrections.
In the above example, the table is stored in the storage device 23 so that the control circuit 21 performs correction process by referring to the table by the container size correction unit, based on the acquired mounting position and the determined mounting angle, but the present disclosure is not limited thereto. For example, as described later, the control circuit 21 may acquire a mounting position of the infrared sensor 7 from any terminal and figure out a mounting angle and a distance between the infrared sensor 7 and the container 2, from dimensions based on the mounting position. In this case, for example, an arithmetic program for the above calculation may be stored in the storage device 23.
For example, by acquiring dimension information from any terminal 30, the control circuit 21 can perform the above correction through the container size correction unit. The terminal 30 may be a mobile terminal. Fig. 10 is a block diagram showing a configuration of the terminal 30. As shown in Fig. 10, the terminal 30 includes a control circuit 31, a communication circuit 32, a display 33, a camera 34, and a storage 35.
The control circuit 31 is e.g. a computer. Similarly to the control circuit 21, the control circuit 31 can be implemented by various processors, etc. For example, the control circuit 31 calls and runs an arithmetic program, etc. stored in the storage 35, to thereby implement various processes such as a dimension input process effected by a mounting position input program 40 that described later.
The communication circuit 32 is an interface device that transmits/receives information to/from the communication circuit 8 via the communication line wiredly or wirelessly. The communication circuit 32 may be connectable to other devices by way of communication lines. The interface device is capable of performing communication compliant with wired communication standards for e.g. USB, Ethernet, etc. The interface device is capable of performing communication compliant with wireless communication standards for e.g. Wi-Fi, Bluetooth, mobile phone line, etc.
The display 33 is a display device composed of e.g. liquid crystal or organic EL. The display 33 also comprises an input device such as a touch panel disposed integrally with the display device. The terminal 30 may comprise, as the input device, a physical button separate from the display 33, instead of the touch panel. The above dimensions may be input through the input device.
The camera 34 is an imaging device having an imaging element such as e.g. CCD or CMOS and can image the heating cooker 1 as described later.
The storage 35 is implemented by e.g. a memory such as DRAM, SRAM, flash memory, etc., HDD, SSD, or other storage device, or a proper combination thereof. The storage 35 may store the mounting position input program 40, etc. As described later, the storage 35 may store therein a program for determining the mounting angle of the movable unit of the mounting unit of the infrared sensor 7 based on the input dimensions.
Fig. 11 shows an example of the mounting position input program 40 displayed on the display 33 of the terminal 30. As shown in Fig. 11, the mounting position input program 40 includes a dimension input unit 41, a heating cooker selection unit 42, a setting angle display unit 43, an angle calculation unit 44, and a deletion unit 45.
The dimension input unit 41 allows input of the dimensions X₁, Y₁, and Z₁ using the display 33. The heating cooker selection unit 42 allows selection of model information, etc. of the heating cooker 1 that is used for the mounting. Since the dimensions X₀ and Y₀ are dimensions determined by the model of the heating cooker 1, selection of the model information leads to automatic input of the above dimensions X₀ and Y₀. The dimensions X₀ and Y₀ may be entered manually like the dimension X₁, etc. When the angle calculation unit 44 is selected, the control circuit 31 calculates a proper mounting angle of the movable unit of the mounting unit of the infrared sensor 7 from the input dimensions and displays the result on the setting angle display unit 43. A table indicative of the relationships between dimensions and mounting angles may previously be stored in the storage 35 so that the control circuit 31 can select a mounting angle based on the input dimensions. As described above, the setting angle display unit 43 can display a proper setting angle calculated of the movable unit of the infrared sensor 7. When the deletion unit 45 is selected, the above input dimensions and the calculated angles are deleted, enabling the dimensions, etc. to be input again.
Via the communication circuits 32 and 8, the control circuit 31 of the terminal 30 may transmit the input dimensions to the control device 20 of the heating cooker 1. In the same manner, the control circuit 31 may transmit the calculated mounting angles to the control device 20 of the heating cooker 1. The control circuit 21 of the heating cooker 1 can acquire information for correcting the container size by the container size correction unit, from the received dimensions and mounting angles.
By having such a configuration, the installer of the heating cooker 1 can easily understand the mounting angles of the movable unit of the mounting unit of the infrared sensor 7, from the information on distance between the top plate 5 and the infrared sensor 7. Thus, the infrared sensor 7 of the heating cooker 1 is mounted at proper mounting angles so that the control circuit 21 of the heating cooker 1 can effect the heating control process based on proper information.
When the camera 34 images the heating cooker 1 instead of inputting the dimensions as described above, the configuration may be such that the control circuit 31 acquires dimensions from the captured image. For example, the control circuit 31 can acquire the dimensions X₀ and Y₀ from shape features, etc. of the main body 4 of the heating cooker 1. The control circuit 31 may acquire the dimensions by receiving model information of the heating cooker 1 from the control device 20 of the heating cooker 1. Similarly, the control circuit 31 may be configured such that it can acquire from the captured image the dimensions of the position at which the infrared sensor 7 is mounted relative to the top plate 5. The heating cooker 1 may also be configured such that the captured image is transmitted to the control device 20 of the heating cooker 1 so that the control circuit 21 acquires the dimensions from the captured image.
By having such a configuration, the installer of the heating cooker 1 can acquire the distance information of the infrared sensor 7 relative to the top plate 5 by taking the captured image without measuring the dimensions and easily understand therefrom the mounting angles of the movable unit of the mounting unit of the infrared sensor 7. As a result, the infrared sensor 7 of the heating cooker 1 is mounted at proper mounting angles so that the control circuit 21 of the heating cooker 1 can effect the heating control process based on proper information.
Although the above mode describes the method for acquiring information for adjusting the mounting angles of the movable unit at a predetermined mounting position at which the infrared sensor 7 has been mounted and the method for acquiring information for the control circuit 31 to correct the container size by the container size correction unit, the present disclosure is not limited thereto.
For example, before mounting the infrared sensor 7, after the main body 4 of the heating cooker 1 has been arranged at a predetermined installing position, planned mounting positions of the top plate 5 of the heating cooker 1 and the infrared sensor 7 may be imaged by the camera 34 of the terminal 30. By imaging the planned mounting positions of the top plate 5 and the infrared sensor 7 in this manner, the control circuit 31 may be configured to specify a region where the infrared sensor 7 can be mounted, on the captured image appearing on the display 33. The control circuit 31 may display on the display the region where the infrared sensor 7 can be mounted, overlapping on a video captured by the camera 34, like so-called augmented reality (AR).
By employing such a configuration, the installer of the heating cooker 1 can easily understand a proper mounting position of the infrared sensor 7 through checking the captured image or video. Thus, the infrared sensor 7 is mounted at the proper mounting position and is mounted at proper mounting angles using the above methods, etc. so that the control circuit 21 of the heating cooker 1 can effect the heating control process based on proper information.

Summary of Embodiment

The heating cooker according to this embodiment described as above may be configured as follows.

First Aspect

A heating cooker comprises: a placement unit on which a container is placed; one or more heating units arranged below the placement unit, for heating the container; an infrared sensor that is disposed substantially above the one or more heating units, the infrared sensor having a plurality of pixels that detect temperatures above the placement unit for the container as temperature information; a container size measurement unit that measures size of the container, based on the temperature information; and a heating control unit that controls heating energy applied to the container by each of the one or more heating units, based on the size of the container.
This enables the heating cooker to measure the size of the container based on the temperatures detected by the infrared sensor, to control the heating energy based on the size. Thus, based on the size of a container to be heated, the heating cooker can apply proper heating energy to the container.

Second Aspect

In the heating cooker of the first aspect, the heating control unit may calculate an energy density of the heating energy applied to the container by each of the one or more heating units, based on the size of the container, and control the heating energy so that the energy density when the container is large and the energy density when the container is small are both included in a predetermined range.
The heating cooker can therefore calculate the energy density of the heating energy applied to the container, based on the size of the container. The heating cooker can thereby control the heating energy so that the energy density has a certain magnitude, based on the size of the container, and apply proper heating energy to the container.

Third Aspect

In the heating cooker of the second aspect, the heating control unit may vary the energy density of the heating energy with respect to a predetermined reference energy density as a reference.
Thus, through the control of generation of air bubbles at the bottom of the container, the heating cooker can provide heating control securing convection of the object to be cooked due to boiling thereof and preventing the object to be cooked from boiling over.

Fourth Aspect

In the heating cooker of the third aspect, the heating control unit may control the heating energy by switching the heating energy between a first heating energy having an energy density larger than the predetermined reference energy density and a second heating energy having an energy density smaller than the predetermined reference energy density.
Thus, through the control of generation of air bubbles at the bottom of the container, the heating cooker can provide heating control that secures convection of the object to be cooked due to boiling thereof by using the first heating energy having an energy density larger than the predetermined reference energy density and that prevents the object to be cooked from boiling over by using the second heating energy having an energy density smaller than the predetermined reference energy density.

Fifth Aspect

In the heating cooker of the third or fourth aspect, the predetermined reference energy density may be within 4 to 6.5 [W/cm²].
Hence, through the control of generation of air bubbles at the bottom of the container by controlling heating energy based on the reference energy density, the heating cooker can provide heating control securing convection of the object to be cooked due to boiling thereof and preventing the object to be cooked from boiling over.

Sixth Aspect

In the heating cooker of any one of the third to fifth aspects, the heating control unit may control the heating energy at a predetermined cycle to change an output peak value and the cycle of the heating energy, or only the output peak value, to thereby vary the energy density.
The heating cooker can thus control generation of air bubbles at the bottom of the container or generation of air bubbles and time thereof, and provide heating control securing convection of the object to be cooked due to boiling thereof and preventing the object to be cooked from boiling over.

Seventh Aspect

In the heating cooker of any one of the first to fifth aspects, the heating control unit may control the heating energy at a predetermined cycle to elongate the cycle of the heating energy of each of the one or more heating units according as the container has a larger size and to shorten the cycle of the heating energy of each of the one or more heating units according as the container has a smaller size.
As a result, the heating cooker can elongate the cycle of the heating energy controlled at a predetermined cycle according as the size of the container to be heated increases, and shorten the cycle according as the size of the container to be heated decreases. The heating cooker can therefore control the heating energy applied to the container at a proper cycle depending on the container size, and properly heat the object to be cooked held in the container.

Eighth Aspect

In the heating cooker of any one of the first to seventh aspects, the container size measurement unit may measure the size of the container, based on the number of pixels having detection temperatures equal to or higher than a predetermined threshold value.
Consequently, the heating cooker can measure the size of the container, based on temperature information of temperatures detected by the infrared sensor. The heating cooker can therefore calculate the heating energy applied to the container, using a container size proper for the heating control. The heating cooker can measure the container size without adding further components.

Ninth Aspect

The heating cooker of any one of the first to eighth aspects may further comprise a cooking status determination unit determining heating state inside the container from the temperature information, wherein the heating control unit may start to control of the heating energy of each of the one or more heating units when the cooking status determination unit detects saturation of temperature variation inside the container.
This enables the heating cooker to provide heating control when the object to be cooked in the container starts to boil. Hence, the heating cooker can prevent boiling over caused by the object to be cooked continuing to boil.

Tenth Aspect

The heating cooker of any one of the first to eighth aspects may further comprise a cooking status determination unit determining heating state inside the container from the temperature information, wherein the heating control unit may start to control of the heating energy of each of the one or more heating units when the cooking status determination unit detects a temporary drop in temperature greater than a predetermined threshold value inside the container.
This enables the heating cooker to provide heating control when foodstuff is put as the object to be cooked into the container. The heating cooker can thus prevent boiling over caused by the object to be cooked continuing to boil.

Eleventh Aspect

The heating cooker of any one of the first to tenth aspects may further comprise: a mounting unit of the infrared sensor, the mounting unit having a movable unit with one or more axes; a mounting position determination unit determining mounting angles of the mounting unit by acquiring information on distance between the placement unit and the mounting unit; and a container size correction unit correcting the size of the container measured by the container size measurement unit, based on the distance information and the mounting angles, wherein the heating control unit may control the heating energy, based on the size of the container corrected by the container size correction unit.
This enables the heating cooker to mount the infrared sensor at proper mounting angles based on the mounting position of the mounting unit of the infrared sensor and to correct the size of the container based on the mounting position and the mounting angles. Accordingly, the heating cooker can provide heating control using more proper information for the container size.

Twelfth Aspect

The heating cooker of the eleventh aspect may comprise a communication circuit communicable wiredly or wirelessly to a terminal having an input unit, wherein the mounting position determination unit may acquire the distance information input to the terminal.
This enables the heating cooker to acquire the information on distance between the placement unit and the mounting unit of the infrared sensor, based on the distance information input to the terminal. Thus, the heating cooker can properly correct the container size by the mounting position determination unit and the container size correction unit and properly control the heating energy based on the size.

Thirteenth Aspect

The heating cooker of the eleventh aspect may comprise a communication circuit communicable wiredly or wirelessly to a terminal having an imaging unit, wherein the mounting position determination unit may acquire the distance information from images of the placement unit and the mounting unit captured by the terminal.
This enables the heating cooker to acquire the information on distance between the placement unit and the mounting unit of the infrared sensor, based on images captured by the terminal. Thus, the heating cooker can properly correct the container size by the mounting position determination unit and the container size correction unit and properly control the heating energy based on the size.

Fourteenth Aspect

The heating cooker of the eleventh aspect may comprise a communication circuit communicable wiredly or wirelessly to a terminal having an imaging unit, wherein the mounting position determination unit may comprise information on a range of distance from the placement unit, within which the mounting unit is attachable, and wherein the heating cooker may transmit to the terminal the information on the range of distance within which the mounting unit is attachable.
Thus, the heating cooker can transmit the information on the range of distance within which the mounting unit of the infrared sensor is attachable, to the terminal. This enables the heating cooker to present a proper mounting position of the mounting unit of the infrared sensor.
The heating cooker described in the present disclosure can be implemented by e.g. collaboration of hardware resources such as processor and memory and software resources (computer program).

INDUSTRIAL APPLICABILITY

According to the present disclosure, a heating cooker can be provided that is capable of both securing convection of the object to be cooked and preventing boiling over, irrespective of the container size, enabling preferred utilization in the industrial field of this type of heating cooker.

REFERENCE SINGS LIST

1: heating cooker
2: container
3: object to be cooked
5: top plate
6A, 6B, 6C: heating coil
7: infrared sensor
20: control device
21: control circuit
24: heating control unit
25: container size measurement unit
26: cooking status determination unit
30: terminal
31: control circuit

Claims

A heating cooker comprising:
a placement unit on which a container is placed;

one or more heating units arranged below the placement unit, for heating the container;

an infrared sensor that is disposed substantially above the one or more heating units, the infrared sensor having a plurality of pixels that detect temperatures above the placement unit for the container as temperature information;

a container size measurement unit that measures size of the container based on the temperature information; and

a heating control unit that controls heating energy applied to the container by each of the one or more heating units, based on the size of the container.
The heating cooker according to claim 1, wherein
the heating control unit calculates an energy density of the heating energy applied to the container by each of the one or more heating units, based on the size of the container, the heating control unit controlling the heating energy so that the energy density when the container is large and the energy density when the container is small are both included in a predetermined range.
The heating cooker according to claim 2, wherein
the heating control unit varies the energy density of the heating energy with respect to a predetermined reference energy density as a reference.
The heating cooker according to claim 3, wherein
the heating control unit controls the heating energy by switching the heating energy between a first heating energy having an energy density larger than the predetermined reference energy density and a second heating energy having an energy density smaller than the predetermined reference energy density.
The heating cooker according to claim 3 or 4, wherein
the predetermined reference energy density is within 4 to 6.5 [W/cm²].
The heating cooker according to any one of claims 3 to 5, wherein
the heating control unit controls the heating energy at a predetermined cycle to change an output peak value and the cycle of the heating energy, or only the output peak value, to vary the energy density.
The heating cooker according to any one of claims 1 to 5, wherein
the heating control unit controls the heating energy at a predetermined cycle

to elongate the cycle of the heating energy of each of the one or more heating units according as the container has a larger size and

to shorten the cycle of the heating energy of each of the one or more heating units according as the container has a smaller size.
The heating cooker according to any one of claims 1 to 7, wherein
the container size measurement unit measures the size of the container, based on the number of pixels having detection temperatures equal to or higher than a predetermined threshold value.
The heating cooker according to any one of claims 1 to 8, further comprising:
a cooking status determination unit determining heating state inside the container from the temperature information, wherein

the heating control unit starts to control the heating energy of each of the one or more heating units when the cooking status determination unit detects saturation of temperature variation inside the container.
The heating cooker according to any one of claims 1 to 8, further comprising:
a cooking status determination unit determining heating state inside the container from the temperature information, wherein
the heating control unit starts to control the heating energy of each of the one or more heating units when the cooking status determination unit detects a temporary drop in temperature greater than a predetermined threshold value inside the container.
The heating cooker according to any one of claims 1 to 10, further comprising:
a mounting unit of the infrared sensor, the mounting unit having a movable unit with one or more axes;

a mounting position determination unit determining mounting angles of the mounting unit by acquiring information on distance between the placement unit and the mounting unit; and

a container size correction unit correcting the size of the container measured by the container size measurement unit, based on the distance information and the mounting angles, wherein

the heating control unit controls the heating energy, based on the size of the container corrected by the container size correction unit.
The heating cooker according to claim 11, comprising:
a communication circuit communicable wiredly or wirelessly to a terminal having an input unit, wherein

the mounting position determination unit acquires the distance information input to the terminal.
The heating cooker according to claim 11, comprising:
a communication circuit communicable wiredly or wirelessly to a terminal having an imaging unit, wherein

the mounting position determination unit acquires the distance information from images of the placement unit and the mounting unit captured by the terminal.
The heating cooker according to claim 11, comprising:
a communication circuit communicable wiredly or wirelessly to a terminal having an imaging unit, wherein

the mounting position determination unit includes information on a range of distance from the placement unit, within which the mounting unit is attachable, and wherein

the heating cooker transmits to the terminal the information on the range of distance within which the mounting unit is attachable.