Microwave oven and control method thereof

Patent metadata

Field	Value
Publication number	US-10187933-B2
Application number	US-201615240426-A
Country	US
Kind code	B2
Filing date	Aug 18, 2016
Priority date	Aug 31, 2015
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

A system and method for safe operation of a microwave oven is disclosed. The heating function of the microwave oven may be automatically disabled upon detection, by the microwave oven, of a metal object entering a heating compartment of the microwave. The detection may be based on magnetic induction. Further, the heating function of the microwave may be automatically enabled and recovered upon detection, by the microwave oven, of a metal object being removed from the heating compartment of the microwave.

First claim

What is claimed is:

1. A microwave oven, comprising:
a case body comprising a heating compartment;
a master control board disposed in the case body; and
a magnetic field generation component and a magnetic field induction component disposed in the heating compartment, wherein the magnetic field generation component generates a magnetic field;
wherein the magnetic field induction component is electrically connected to the master control board;
wherein the magnetic field induction component is configured to output a first induction signal upon detecting a first change in the magnetic field, and output a second induction signal upon detecting a second change in the magnetic field;
wherein the master control board is configured to determine, according to the first induction signal, whether a metal object has entered or is entering the heating compartment, and to disable a heating function of the heating compartment in response to determining that the metal object has entered or is entering the heating compartment;
wherein, when determining whether the metal object has entered or is entering the heating compartment according to the first induction signal, the master control board is further configured to detect that the first induction signal increases or decreases gradually, and to determine that the metal object has entered or is entering the heating compartment;
wherein the master control board is further configured to determine, according to the second induction signal, whether the metal object has been or is being removed from the heating compartment, and to enable the heating function of the heating compartment in response to determining that the metal object has been or is being removed from the heating compartment;
wherein, when determining whether the metal object has been or is being removed from the heating compartment according to the second induction signal, the master control board is further configured to detect that the second induction signal is of an opposite sign to the first induction signal when the metal object enters the heating compartment, and to determine that the metal object has been or is being removed from the heating compartment;
a reset button; and
wherein the master control board is configured to:
detect whether the reset button is pressed,
in response to detecting that the reset button is pressed, determine that the metal object has been or is being removed from the heating compartment, and
enable the heating function of the heating compartment in response to determining that the metal object has been or is being removed from the heating compartment.

2. The microwave oven of claim 1 , wherein the magnetic field induction component is disposed at an entrance of the heating compartment.

3. The microwave oven of claim 1 , wherein the magnetic field induction component comprises only one magnetic induction sensor.

4. The microwave oven of claim 1 , wherein the magnetic field induction component comprises multiple magnetic field induction sensors.

5. The microwave oven of claim 4 , wherein when the magnetic field induction component comprises multiple magnetic field induction sensors, the master control board is configured to derive a shape and size of the metal object according to a set of first induction signals detected by the multiple magnetic field induction sensors.

6. The microwave oven of claim 1 , wherein the magnetic field induction component is a magneto-resistive sensor.

7. The microwave oven of claim 1 , wherein the magnetic field generation component is a permanent magnet.

8. The microwave oven of claim 1 , wherein the magnetic field generation component is a magnetic coil connected electrically to the master control board.

9. The microwave oven of claim 1 , further comprising a radio communication component connected electrically to the master control board, wherein the radio communication component comprises at least one of a Wireless Fidelity (Wi-Fi) network interface, a Bluetooth interface, and a zigbee interface.

10. The microwave oven of claim 1 , further comprising a display screen connected electrically to the master control board.

11. A control method for operating a microwave oven, comprising:
detecting, by a magnetic field induction component disposed at an entrance of a heating compartment of the microwave oven, a first induction signal due to a first change of a magnetic field generated by a magnetic field generation component disposed at the entrance of the heating compartment of the microwave oven;
determining, by a master control board electrically connected to the magnetic field induction component, whether a metal object has entered or is entering the heating compartment according to the first induction signal; and
disabling, by the master control board, a heating function of the heating compartment in response to determining that a metal object has entered or is entering the heating compartment;
wherein the determining by the master control board whether the metal object has entered or is entering the heating compartment according to the first induction signal comprises: detecting, by the master control board, that the first induction signal increases or decreases gradually, and determining, by the master control board, that the metal object has entered or is entering the heating compartment;
detecting, by the magnetic field induction component, a second induction signal due to a second change of the magnetic field generated by the magnetic field generation component;
determining, by the master control board, whether the metal object has been or is being removed from the heating compartment according to the second induction signal or according to a reset button; and
enabling, by the master control board, the heating function of the heating compartment in response to determining by the master control board that the metal object has been or is being removed from the heating compartment;
wherein the determining by the master control board whether the metal object has been or is being removed from the heating compartment according to the second induction signal comprises: detecting, by the master control board, that the second induction signal is of an opposite sign to the first induction signal when the metal object enters the heating compartment, and determining, by the master control board, that the metal object has been or is being removed from the heating compartment;
wherein the determining by the master control board whether the metal object has been or is being removed from the heating compartment according to the reset button comprises: detecting, by the master control board, whether the reset button is pressed, and in response to detecting that the reset button is pressed, determining, by the master control board, that the metal object has been or is being removed from the heating compartment.

12. The method of claim 11 , further comprising:
causing, by the master control board, a radio communication component of the microwave oven connected electrically to the master control board, to send an alarm prompt to a mobile terminal for prompting a user remove the metal object from the heating compartment of the microwave oven, in response to determining by the master control board that a metal object has entered or is entering the heating compartment.

13. The method of claim 11 , further comprising:
causing, by the master control board, a display screen of the microwave oven connected electrically to the master control board, to display an alarm prompt for prompting a user to remove the metal object from the heating compartment of the microwave oven, in response to determining by

Assignees

• Xiaomi Inc

Inventors

• Liu Dongxu
• Wu Yi
• Yang Nuo

Classifications

• H05B6/668

  Microwave heating devices connected to a telecommunication network · CPC title

• H05B6/666 Primary

  Safety circuits (emergency protective circuits in general H02H) · CPC title

• H05B6/6447 Primary

  Method of operation or details of the microwave heating apparatus related to the use of detectors or sensors · CPC title

• H05B6/68 Primary

  for monitoring or control · CPC title