INDUCTION HEATING COOKER, INDUCTION HEATING COOKING METHOD, INDUCTION HEATING COOKING PROGRAM, RESONANCE SOUND DETECTION DEVICE, RESONANCE SOUND DETECTION METHOD, AND RESONANCE SOUND DETECTION PROGRAM

• US 20090173731A1
• Filed: 05/01/2007
• Published: 07/09/2009
• Est. Priority Date: 05/11/2006
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Nagamitsu, Sachio, Noda, Makiko
• Granted Patent: US 8,791,399 B2
• Time in Patent Office: Days
• US Class Current: 219/622
• CPC Class Codes: H05B 6/062 for cooking plates or the like

Abstract

An object of the invention is to accurately detect a state of an object to be heated in a cooking vessel and effectively avoid cooking failure. An induction heating section (13) inductively heats a cooking vessel (11). A vibration detecting section (14) detects a vibration of the cooking vessel (11) via a top plate (12). A vibration waveform extracting section (15) extracts a vibration waveform of a frequency component having a frequency equal to a predetermined multiplication product of an induction heating frequency, from a waveform of the vibration detected by the vibration detecting section (14). A determining section (16) determines a state of an object to be heated, based on the vibration waveform extracted by the vibration waveform extracting section (15).

Claims

1. An induction heating cooker, comprising:

an induction heating section for inductively heating a cooking vessel for containing an object to be heated;

a vibration detecting section for detecting a vibration of the cooking vessel;

a vibration waveform extracting section for extracting a vibration waveform of a frequency component having a frequency of about twice as large as an induction heating frequency, from a waveform of the vibration detected by the vibration detecting section; and

a determining section for determining a state of the object to be heated, based on the vibration waveform extracted by the vibration waveform extracting section.

2. The induction heating cooker according to claim 1, wherein

the vibration waveform extracting section extracts an amplitude of the frequency component having the frequency of about twice as large as the induction heating frequency by subjecting the waveform of the vibration detected by the vibration detecting section to a fast Fourier transformation.

3. The induction heating cooker according to claim 1, wherein

the vibration waveform extracting section calculates an absolute value of a difference between a peak value and a bottom value of the waveform of the vibration detected by the vibration detecting section to extract the calculated absolute value, as an amplitude of the frequency component having the frequency of about twice as large as the induction heating frequency.

4. The induction heating cooker according to claim 2, wherein

the determining section determines the state of the object to be heated, with use of a maximum value of the amplitude extracted by the vibration waveform extracting section at a predetermined sampling time interval.

5. The induction heating cooker according to claim 1, further comprising:

a waveform change pattern storing section for storing a waveform change pattern on a vibration waveform of the cooking vessel in correlation to at least one of a kind of the cooking vessel, a kind of the object to be heated, and a quantity of the object to be heated, wherein

the determining section includes a waveform change pattern specifying section for comparing a waveform change pattern of the vibration waveform to be extracted by the vibration waveform extracting section with the waveform change pattern stored in the waveform change pattern storing section to specify at least one of the kind of the cooking vessel, the kind of the object to be heated, and the quantity of the object to be heated.

6. The induction heating cooker according to claim 1, wherein

the determining section determines whether the object to be heated is in a boiling state, based on the vibration waveform extracted by the vibration waveform extracting section.

7. The induction heating cooker according to claim 1, wherein

the determining section determines that another object to be heated is put in the cooking vessel, based on the vibration waveform extracted by the vibration waveform extracting section.

8. The induction heating cooker according to claim 3, wherein

the induction heating section includes a plurality of induction heating sections for inductively heating a plurality of cooking vessels,

the vibration waveform extracting section calculates the absolute value of the difference between the peak value and the bottom value of the vibration waveform of the frequency component having the frequency of about twice as large as the induction heating frequency of each of the induction heating sections to extract the calculated absolute value, as the amplitude of the frequency component having the frequency of about twice as large as the corresponding induction heating frequency, and

the determining section compares each of the amplitudes extracted by the vibration waveform extracting section with a predetermined value to determine the state of the object to be heated with respect to each of the induction heating sections.

9. The induction heating cooker according to claim 1, further comprising:

a heating controlling section for controlling the induction heating section depending on the state of the object to be heated determined by the determining section.

10. The induction heating cooker according to claim 5, further comprising:

a heating controlling section for controlling the induction heating section depending on the state of the object to be heated determined by the determining section; and

a changing section for changing at least one of a predetermined value, and the waveform change pattern stored in the waveform change pattern storing section, depending on at least one of the state of the object to be heated determined by the determining section, and a controlled state of the induction heating section to be controlled by the heating controlling section.

11. The induction heating cooker according to claim 1, wherein

the determining section determines whether the object to be heated is in a boiling state, exclusively based on a waveform change pattern of a vibration waveform of the cooking vessel.

12. The induction heating cooker according to claim 2, wherein

the induction heating section includes a plurality of induction heating sections for inductively heating a plurality of cooking vessels at induction heating frequencies different from each other, respectively,

the vibration waveform extracting section extracts the amplitude of the frequency component having the frequency of about twice as large as each of the induction heating frequencies of the induction heating sections by subjecting the waveform of the vibration detected by the vibration detecting section to a fast Fourier transformation, and

the determining section compares each of the amplitudes extracted by the vibration waveform extracting section with a predetermined value to determine the state of the object to be heated with respect to each of the induction heating sections.

13. The induction heating cooker according to claim 1, wherein

the induction heating section includes a plurality of induction heating sections for inductively heating a plurality of cooking vessels,

the induction heating cooker further includes:

a plurality of temperature detecting sections for detecting temperatures of the cooking vessels, respectively; and

a heating controlling section for lowering an induction heating output of one of the induction heating sections, based on the temperature of each of the cooking vessels detected by the temperature detecting sections, and

the determining section determines the state of the object to be heated with respect to each of the induction heating sections by detecting a change in the vibration waveform extracted by the vibration waveform extracting section.

14. The induction heating cooker according to claim 6, wherein

the vibration detecting section detects a vibration of the cooking vessel in an ultrasonic frequency band, and detects a vibration of the cooking vessel in an audible frequency band,

the vibration waveform extracting section extracts a first vibration waveform of the frequency component having the frequency of about twice as large as the induction heating frequency, from a waveform of the vibration in the ultrasonic frequency band detected by the vibration detecting section, and extracts a second vibration waveform of the vibration in the audible frequency band detected by the vibration detecting section, and

the determining section determines whether the object to be heated is in a boiling state, based on the first vibration waveform extracted by the vibration waveform extracting section to compensate for the determination as to the boiling state, based on a change in the second vibration waveform extracted by the vibration waveform extracting section.

15. The induction heating cooker according to claim 6, further comprising:

a temperature detecting section for detecting a temperature of the cooking vessel; and

a time-based temperature change amount calculating section for calculating a time-based change amount of the temperature of the cooking vessel detected by the temperature detecting section, wherein

the determining section determines that the object to be heated is not in a boiling state, in the case where it is judged that the time-based change amount calculated by the time-based temperature change amount calculating section is larger than a predetermined value or smaller than 0.

16. An induction heating cooking method, comprising:

an induction heating step of inductively heating a cooking vessel for containing an object to be heated;

a vibration detecting step of detecting a vibration of the cooking vessel;

a vibration waveform extracting step of extracting a vibration waveform of a frequency component having a frequency of about twice as large as an induction heating frequency, from a waveform of the vibration detected in the vibration detecting step; and

a determining step of determining a state of the object to be heated, based on the vibration waveform extracted in the vibration waveform extracting step.

17. A computer readable recording medium storing an induction heating cooking program for causing a computer to function as at least:

an induction heating section for inductively heating a cooking vessel for containing an object to be heated;

a vibration detecting section for detecting a vibration of the cooking vessel;

a vibration waveform extracting section for extracting a vibration waveform of a frequency component having a frequency of about twice as large as an induction heating frequency, from a waveform of the vibration detected by the vibration detecting section; and

a determining section for determining a state of the object to be heated, based on the vibration waveform extracted by the vibration waveform extracting section.

18-25. -25. (canceled)