Induction heating device and method for determining loaded-object on the induction heating device

Patent metadata

Field	Value
Publication number	US-10904953-B2
Application number	US-201816030984-A
Country	US
Kind code	B2
Filing date	Jul 10, 2018
Priority date	Nov 7, 2017
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

An induction heating device includes a working coil, an inverter, an inverter driving unit configured to apply a switching signal to the inverter to enable the inverter to perform a switching operation, a control unit configured to generate and apply a control signal to the inverter driving unit to cause the inverter driving unit to generate the switching signal based on the control signal, and a determination unit configured to determine a type of an object disposed on the induction heating device based on (i) a first resonant current value measured from the working coil in response to operation of the inverter by the switching signal having a first operation frequency and (ii) a second resonant current value measured from the working coil in response to operation of the inverter by the switching signal having a second operation frequency.

First claim

What is claimed is:

1. An induction heating device, comprising:
a working coil;
an inverter configured to apply current to the working coil based on a switching operation of the inverter;
an inverter driving unit configured to apply a switching signal to the inverter to enable the inverter to perform the switching operation, the switching signal having a first operation frequency and a second operation frequency;
a control unit that is configured to generate a control signal, that is configured to apply the control signal to the inverter driving unit, and that is configured to cause the inverter driving unit to generate the switching signal based on the control signal; and
a determination unit configured to:
determine a type of an object disposed on the induction heating device based on (i) a first resonant current value that is measured from the working coil in response to operation of the inverter by the switching signal having the first operation frequency and (ii) a second resonant current value that is measured from the working coil in response to operation of the inverter by the switching signal having the second operation frequency,
based on the first resonant current value, determine whether the object has an inductive-heating property, and
in response to a determination that the object has the inductive-heating property based on the first resonant current value, compare a difference between the first resonant current value and the second resonant current value to a reference value to confirm that the object has the inductive-heating property.

2. The induction heating device of claim 1 , wherein the determination unit is further configured to:
compare the first resonant current value to a first reference value; and
based on a comparison of the first resonant current value to the first reference value, determine presence of the object on the induction heating device or absence of the object from the induction heating device.

3. The induction heating device of claim 2 , wherein the determination unit is further configured to:
compare the first resonant current value to a second reference value; and
based on a comparison of the first resonant current value to the second reference value, determine whether the object on the induction heating device has the inductive-heating property.

4. The induction heating device of claim 3 , wherein the reference value is a third reference value that is different from the first reference value and the second reference value.

5. The induction heating device of claim 2 , wherein the control unit is further configured to, based on the determination unit determining absence of the object from the induction heating device, stop supplying the control signal to the inverter driving unit.

6. The induction heating device of claim 1 , wherein the determination unit is further configured to, in response to the determination that the object has the inductive-heating property based on the first resonant current value, determine the difference between the first resonant current value and the second resonant current value.

7. The induction heating device of claim 1 , wherein the control unit is further configured to, based on the determination unit determining that the object on the induction heating device does not have the inductive-heating property, stop supplying the control signal to the inverter driving unit.

8. The induction heating device of claim 1 , wherein the determination unit is further configured to determine that the object has the inductive-heating property based on the difference between the first resonant current value and the second resonant current value being less than the reference value.

9. The induction heating device of claim 1 , further comprising a sensor connected to the determination unit and configured to measure a resonant current from the working coil based on operation of the inverter driving unit.

10. A method for detecting and identifying an object disposed on an induction heating device, the method comprising:
operating an inverter of the induction heating device at a first operation frequency;
measuring a first resonant current value from a working coil based on operation of the inverter at the first operation frequency;
based on the first resonant current value, determining at least one of presence of the object on the induction heating device, absence of the object from the induction heating device, or a type of the object on the induction heating device;
operating the inverter of the induction heating device at a second operation frequency;
measuring a second resonant current value from the working coil based on operation of the inverter at the second operation frequency; and
determining the type of the object based on the second resonant current value,
wherein determining the type of the object comprises:
based on the first resonant current value, determining whether the object on the induction heating device has an inductive-heating property, and
in response to a determination that the object has the inductive-heating property based on the first resonant current value, comparing a difference between the first resonant current value and the second resonant current value to a reference value to confirm that the object has the inductive-heating property.

11. The method of claim 10 , wherein determining at least one of presence of the object, absence of the object, or the type of the object comprises:
comparing the first resonant current value to a first reference value; and
based on a comparison of the first resonant current value to the first reference value, determining presence of the object on the induction heating device or absence of the object from the induction heating device.

12. The method of claim 11 , wherein determining at least one of presence of the object, absence of the object, or the type of the object comprises:
comparing the first resonant current value to a second reference value; and
based on a comparison of the first resonant current value to the second reference value, determining whether the object on the induction heating device has the inductive-heating property.

13. The method of claim 12 , wherein determining presence or absence of the object on the induction heating device comprises:
determining presence of the object based on the first resonant current value being greater than or equal to the first reference value;
determining absence of the object based on the first resonant current value being less than the first reference value; and
based on the first resonant current value being between the first reference value and the second reference value, determining that the object is present on the induction heating device and that the object has the inductive-heating property,
wherein the second reference value is greater than the first reference value.

14. The method of claim 12 , wherein operating the inverter of the induction heating device at the second operation frequency comprises operating the inverter of the induction heating device at the second operation frequency in response to a determination that the first resonant current value being less than the second reference value.

15. The method of claim 12 , wherein the reference value is a third reference value that is different from the first reference value and the second reference value.

16. The method of claim 10 , wherein determining the type of the object further comprises, in response to the determination that the object has the inductive-heating property based on the first resonant current value, determining

Assignees

• Lg Electronics Inc

Inventors

• Yoon Bada
• Kang John
• Park Wongyu

Classifications

• H05B2213/05

  Heating plates with pan detection means · CPC title

• H05B6/062 Primary

  for cooking plates or the like · CPC title

• H02M7/539

  with automatic control of output wave form or frequency (H02M7/5375 - H02M7/5387 take precedence) · CPC title

• H05B6/1209

  induction cooking plates or the like and devices to be used in combination with them · CPC title

• H05B1/02

  Automatic switching arrangements specially adapted to apparatus {; Control of heating devices} (thermally-actuated switches H01H37/00) · CPC title