HEATING/COOKING EQUIPMENT

• US 20110278285A1
• Filed: 01/21/2010
• Published: 11/17/2011
• Est. Priority Date: 01/23/2009
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Hirota, Izuo, Ogasawara, Fumitaka, Ishimaru, Naoaki, Miyauchi, Takahiro, Sadahira, Masafumi, Fujinami, Tomoya
• Granted Patent: US 9,078,295 B2
• Time in Patent Office: Days
• US Class Current: 219/780
• CPC Class Codes: H05B 6/062 for cooking plates or the like
• CPC Class Codes: H05B 6/1209 induction cooking plates or the like and devices to be used in combination with them
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

Abstract

There is provided a heating/cooking equipment capable of accurately determining boiling over. The heating/cooking equipment includes: a top plate (104) connected to a reference potential; a heating unit (105) configured to heat an object to be heated placed on the top plate; an electrode (106) arranged under the top plate; a capacitance detecting unit (107) configured to detect the electrostatic capacitance of the electrode; a boiling over detecting unit (108) configured to detect whether or not a material to be cooked in the object to be heated has boiled over on the top plate, based on a value of the electrostatic capacitance detected by the capacitance detecting unit; and a control unit (109) configured to control the heating operation of the heating unit based on a boiling over detection result from the boiling over detecting unit. The capacitance detecting unit (107) detects a change in the electrostatic capacitance of the electrode by exploiting capacitive coupling between the electrode and the reference potential which is enhanced by increase in a boiled over amount of the material to be cooked with moisture contained in the material to be cooked functioning as a dielectric when the material to be cooked boils over on the top plate.

Claims

1. A heating/cooking equipment, comprising:

a top plate connected to a reference potential;

a heating unit configured to heat an object to be heated placed on the top plate;

at least one electrode arranged under the top plate;

a capacitance detecting unit configured to detect an electrostatic capacitance of the electrode;

a boiling over detecting unit configured to detect whether or not a material to be cooked in the object to be heated has boiled over on the top plate, based on a value of the electrostatic capacitance of the electrode detected by the capacitance detecting unit; and

a control unit configured to control a heating operation of the heating unit based on a detection result of boiling over by the boiling over detecting unit, wherein

the capacitance detecting unit detects a change in the electrostatic capacitance of the electrode by exploiting capacitive coupling between the electrode and the reference potential which is enhanced by increase in a boiled over amount of the material to be cooked with moisture contained in the material to be cooked functioning as a dielectric when the material to be cooked boils over on the top plate connected to the reference potential.

2. The heating/cooking equipment according to claim 1, further comprising:

a metal member provided under the top plate and near the electrode.

3. The heating/cooking equipment according to claim 2, wherein

the heating unit includes:

a heating coil configured to inductively heat the object to be heated as being supplied with high-frequency power; and

a high-frequency power supplying unit configured to supply the high-frequency power to the heating coil.

4. The heating/cooking equipment according to claim 3, wherein

the metal member is a copper winding wire used for the heating coil.

5. The heating/cooking equipment according to claim 4, wherein

a shape of the electrode is an arc-shape that is positioned substantially concentrically on the heating coil.

6. The heating/cooking equipment according to claim 3, further comprising:

a filter configured to remove an induction heating frequency component superimposed on the change of the electrostatic capacitance of the electrode detected by the capacitance detecting unit.

7. The heating/cooking equipment according to claim 3, wherein

the boiling over detecting unit makes a determination as to boiling over, by observing an induction heating frequency component generated due to an effect of induction heating by capacitive coupling between the electrode and the heating coil.

8. The heating/cooking equipment according to claim 1, wherein the electrode is printed on the top plate.

9. The heating/cooking equipment according to claim 1, wherein

the capacitance detecting unit observes a change in an impedance due to an increase in the electrostatic capacitance of the electrode by using a voltage dividing circuit.

10. The heating/cooking equipment according to claim 3, further comprising:

a boiled over material contacting state detecting unit configured to sense an increase in the electrostatic capacitance of the electrode due to capacitive coupling between the electrode and the object to be heated via a boiled over material physically in contact with the object to be heated, to recognize an electric field change of induction heating-origin directly transferred from the object to be heated, wherein

the boiling over detecting unit detects boiling over of the material to be cooked, based on a detection result of the capacitance detecting unit and a detection result of the boiled over material contacting state detecting unit.

11. The heating/cooking equipment according to claim 10, further comprising:

a boiled over material contacting state confirming unit configured to execute, through the control unit, heating control for confirming whether the increase in the electrostatic capacitance of the electrode sensed by the boiled over material contacting state detecting unit is due to the capacitive coupling between the electrode and the object to be heated via the material to be cooked having boiled over.

12. The heating/cooking equipment according to claim 11, wherein

the heating control is, upon sensing the increase in the electrostatic capacitance of the electrode by the boiled over material contacting state detecting unit, to stop a heating operation performed by the heating coil for a prescribed time, and after a lapse of the prescribed time, to operate the heating coil with smaller heating power as compared to heating power before the stop of the heating operation.

13. The heating/cooking equipment according to claim 3, further comprising:

a reporting unit configured to report an occurrence of boiling over to a user, wherein

the boiling over detecting unit is a control report time adjusting unit configured to execute, upon a determination of the occurrence of boiling over, a boiling over detecting process that includes an operation of controlling a heating amount of the heating coil through the control unit and an operation of adjusting a time until the reporting unit reports the occurrence of boiling over to the user.

14. The heating/cooking equipment according to claim 13, wherein

the control report time adjusting unit is configured to compare a detection value of the capacitance detecting unit with a prescribed threshold value, to detect boiling over of the material to be cooked,

the heating/cooking equipment further comprising:

a threshold value determining unit configured to determine the prescribed threshold value based on a value of the electrostatic capacitance of the electrode at the start of heating.

15. The heating/cooking equipment according to claim 13, wherein

a plurality of the electrodes are included, and

the control report time adjusting unit executes the boiling over detecting process based on a value of the electrostatic capacitance of each of a plurality of the electrodes.

16. The heating/cooking equipment according to claim 15, wherein

when the electrostatic capacitance of each of a plurality of the electrodes changes at the start of heating, the control report time adjusting unit simultaneously controls the heating unit to stop heating and controls the reporting unit to make a report.

17. The heating/cooking equipment according to claim 15, wherein

when the electrostatic capacitance of at least one of a plurality of the electrodes changes at the start of heating, the control report time adjusting unit simultaneously controls the heating unit to stop heating and controls the reporting unit to make a report.

18. The heating/cooking equipment according to claim 13, wherein

a plurality of the heating coils are included, and

the control report time adjusting unit controls the heating amount of all of the heating coils when boiling over of the material to be cooked is detected.

19. The heating/cooking equipment according to claim 13, further comprising:

a human body detecting unit configured to detect whether or not a person is present, wherein

the control report time adjusting unit executes the boiling over detecting process based on a detection result of the human body detecting unit.

20. The heating/cooking equipment according to claim 13, further comprising:

an object to be heated shift detecting unit configured to detect whether or not the object to be heated is shifted, wherein

the control report time adjusting unit prohibits execution of the boiling over detecting process, when the object to be heated shift detecting unit detects shift of the object to be heated.

21. The heating/cooking equipment according to claim 13, further comprising:

a temperature detecting unit configured to detect a temperature of the object to be heated, wherein

the control report time adjusting unit prohibits execution of the boiling over detecting process, when the temperature of the object to be heated detected by the temperature detecting unit is lower than a boiling point of water.