Shield device, induction heating type cooktop, and induction heating type cooktop system including same

Patent metadata

Field	Value
Publication number	US-2024324076-A1
Application number	US-202218579711-A
Country	US
Kind code	A1
Filing date	Jul 8, 2022
Priority date	Jul 16, 2021
Publication date	Sep 26, 2024
Grant date	—

Abstract

Discussed herein is an induction heating type cooktop including a glass upper plate configured to have a heating region to heat a cooking container, a working coil configured to generate a first magnetic field to heat the cooking container, an inverter comprising a switching element driven to allow a current to flow through the working coil, and a shield circuit configured to generate a second magnetic field to negate the effects of the first magnetic field.

First claim

1 . An induction heating type cooktop comprising:
a glass upper plate configured to have a heating region to heat a cooking container; a working coil configured to generate a first magnetic field to heat the cooking container; an inverter comprising a switching element driven to allow a current to flow through the working coil; and a shield circuit configured to generate a second magnetic field to negate effects of the first magnetic field.

2 . The induction heating type cooktop of claim 1 , wherein the shield circuit comprises a shield coil and a shield capacitor.

3 . The induction heating type cooktop of claim 2 , wherein the shield circuit further comprises a first switch configured to determine whether to operate in an electromagnetic wave reduction mode.

4 . The induction heating type cooktop of claim 3 , wherein the first switch is turned on or off at a zero crossing point.

5 . The induction heating type cooktop of claim 2 , wherein the shield circuit further comprises:
a second switch configured to determine whether to operate a heating power reinforcement mode, and a heating power reinforcement capacitor.

6 . The induction heating type cooktop of claim 5 , wherein the shield capacitor and the heating power reinforcement capacitor are connected in parallel, and
wherein the second switch is connected between the shield capacitor and the heating power reinforcement capacitor.

7 . The induction heating type cooktop of claim 6 , wherein the second switch is turned off in a heating power enhancement mode and is turned on in an electromagnetic wave reduction mode.

8 . The induction heating type cooktop of claim 5 , wherein the second switch is turned off when a size of the cooking container is larger than a preset reference size, and
wherein the second switch is turned on when the size of the cooking container is smaller than the reference size.

9 . The induction heating type cooktop of claim 8 , further comprising an output unit configured to output a notification when the size of the cooking container is smaller than or equal to the reference size and the cooking container is not aligned to the heating region.

10 . A shield device usable in an induction heating type cooktop including a working coil, the shield device comprising:
a case disposed on an upper portion of the cooktop; and a shield coil disposed inside of the case.

11 . An induction heating type cooktop system comprising:
a cooktop comprising a working coil and a glass upper plate configured to have a heating region through which a magnetic field generated in the working coil can pass; and a shield device disposed on the cooktop, wherein the shield device comprises:
a case disposed on an upper portion of the cooktop; and
a shield coil disposed inside of the case.

12 . The induction heating type cooktop system of claim 11 , wherein an inner diameter of the shield coil is larger than an outer diameter of the working coil.

13 . The induction heating type cooktop system of claim 11 , wherein an inner diameter of the shield coil is larger than an outer diameter of the heating region of the cooktop.

14 . The induction heating type cooktop system of claim 11 , wherein the case is provided with a guide configured to guide a position of the shield device.

15 . The induction heating type cooktop system of claim 11 , wherein the shield device further comprises an energy accumulation circuit having a shield capacitor connected to the shield coil.

16 . The induction heating type cooktop of claim 1 , further comprising a ferrite core disposed below the working coil,
wherein the ferrite core negates the effects of a portion of the first magnetic field near the ferrite core.

17 . The induction heating type cooktop of claim 16 , further comprising an aluminum plate disposed below the ferrite core.

18 . The induction heating type cooktop of claim 1 , wherein the shield circuit further comprises an aluminum plate.

19 . The induction heating type cooktop of claim 18 , wherein the working coil is disposed on an upper portion of the aluminum plate.

20 . The shield device of claim 10 , further comprising an energy accumulation circuit having a shield capacitor connected to the shield coil.

Assignees

• Lg Electronics Inc

Inventors

• Kim Sungkyu
• Lee Seonghun
• Kwak Bongsik
• Kim Hongkwon

Classifications

• H05B6/1254

  using conductive pieces to direct the induced magnetic field · CPC title

• H05B6/1236

  adapted to induce current in a coil to supply power to a device and electrical heating devices powered in this way · CPC title

• H05B6/1245 Primary

  with special coil arrangements · CPC title

• H05B6/062

  for cooking plates or the like · CPC title

• Y02B40/00

  Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers · CPC title