INDUCTION HEAT COOKING DEVICE

• US 20110000904A1
• Filed: 02/19/2009
• Published: 01/06/2011
• Est. Priority Date: 02/19/2008
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Noguchi, Shintaro, Ishio, Yoshiaki, Sakakibara, Kuniaki, Watanabe, Kenji, Tominaga, Hiroshi
• Granted Patent: US 8,796,599 B2
• Time in Patent Office: Days
• US Class Current: 219/624
• CPC Class Codes: H05B 2213/04 Heating plates with overheat protection means
• CPC Class Codes: H05B 2213/07 Heating plates with temperature control means
• 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

Abstract

An induction heat cooking device is provided that finishes preheating in a short time and maintains the temperature obtained at the finish of the preheating. When a preheating heating mode is selected as an operation mode, a control unit (8) arranged in the induction heat cooking device starts operation in a preheating mode in which a cooking container is heated with a first heating output. When an increment of an output value of an infrared sensor exceeds a first predetermined increment since the heating starts with the first heating output, the control unit causes a notification unit to notify a user that the preheating is finished, and the operation mode is changed to a waiting mode for performing heating with a second heating output that is lower than the first heating output. Further, when the user sets a heating power by means of a heating power setting unit in the preheating mode, the control unit prohibits changing to the heating power set by the user. When the user sets a heating power by means of a heating power setting unit in the waiting mode, the control unit permits changing to the heating power set by the user, and the operation mode is changed to a heating mode for performing heating with a third heating output corresponding to the heating power set by the user.

Claims

1. An induction heat cooking device comprising:

a top plate made of a material through which an infrared light is transmitted;

a heating coil for receiving a high frequency current to heat a cooking container placed on the top plate by induction;

an inverter circuit for providing the high frequency current to the heating coil;

an operation unit including an operation mode setting unit for setting an operation mode of the inverter circuit and a heating power setting unit for setting a heating power of the inverter circuit;

an infrared sensor for detecting an infrared light that is emitted from a bottom surface of the cooking container and transmitted through the top plate;

a control unit for controlling an output of the inverter circuit, based on an output of the infrared sensor and a setting inputted to the operation unit; and

a notification unit,

wherein the operation mode includes a preheating heating mode for performing preheating before performing heating,

wherein when the operation mode is set to the preheating heating mode, the control unit starts operation in a preheating mode for heating the cooking container with a first heating output corresponding to the preheating heating mode, and wherein when an increment of an output value of the infrared sensor is more than a first predetermined increment since the heating starts with the first heating output, the control unit causes the notification unit to notify a user that the preheating is finished, and the operation mode is changed to a waiting mode for performing heating with a second heating output that is lower than the first heating output,

and wherein when the user sets a heating power by means of the heating power setting unit in the preheating mode, change to the heating power set by the user is prohibited, and wherein when the user sets a heating power by means of the heating power setting unit in the waiting mode, change to the heating power set by the user is permitted, and the operation mode is changed to the heating mode for performing heating with a third heating output corresponding to the heating power set by the user.

2. The induction heat cooking device according to claim 1, wherein the operation mode is changed to the waiting mode when the increment of the output value of the infrared sensor with respect to a predetermined initial output value exceeds the first predetermined increment, instead of the increment of the output value of the infrared sensor since the heating starts with the first heating output, and wherein the predetermined initial output value is an output value of the infrared sensor that is obtained when the cooking container, having such a temperature that the gradient of increase in the output of the infrared sensor with respect to a change of temperature of the cooking container is equal to or less than a predetermined value, is placed on the top plate.

3. The induction heat cooking device according to claim 1 further comprising a timer count unit for counting a time from when the operation mode is changed to the waiting mode,

wherein when the time counted by the timer count unit reaches a first predetermined time in the waiting mode, the control unit halts heating or changes the second heating output to a heating output that is smaller than the second heating output.

4. The induction heat cooking device according to claim 3, wherein when the time counted by the timer count unit reaches a first predetermined time, the notification unit notifies the user that the heating is halted or the second heating output is changed to the heating output that is smaller than the second heating output.

5. The induction heat cooking device according to claim 3, wherein when the time counted by the timer count unit reaches a second predetermined time that is shorter than the first predetermined time, the notification unit issues a notification for prompting the user to start cooking.

6. The induction heat cooking device according to claim 3, wherein the operation unit includes a plurality of switches, and wherein the timer count unit stops counting when a predetermined switch in the operation unit is pressed down before the counted time reaches the first predetermined time.

7. The induction heat cooking device according to claim 3, wherein the operation unit includes a plurality of switches, and wherein when a predetermined switch in the operation unit is pressed down before the counted time reaches the first predetermined time, the timer count unit resets counting and starts counting all over again, and the timer count unit resets the first predetermined time to a third predetermined time that is longer than the first predetermined time,

wherein when the counted time since the resetting reaches the third predetermined time, the heating is halted, or the second heating output is changed to a heating output that is smaller than the second heating output.

8. The induction heat cooking device according to claim 3 further comprising a numerical display unit for displaying a number,

wherein the numerical display unit displays how much time it takes for the time counted by the timer count unit to reach the first predetermined time.

9. The induction heat cooking device according to claim 1 further comprising a heating power display unit for displaying a heating power,

wherein the heating power display unit does not display the heating power in the preheating mode, and displays the heating power after the operation mode is changed to the waiting mode.

10. The induction heat cooking device according to claim 1 further comprising an operation mode display unit for displaying a mark representing the operation mode,

wherein in the preheating mode, the operation mode display unit lights a heating mark indicating that the heating is performed and blinks a preheating mark indicating that the preheating function is operated.

11. The induction heat cooking device according to claim 10, wherein when the operation mode is changed to the waiting mode, the operation mode display unit stops blinking the preheating mark and lights the preheating mark.

12. The induction heat cooking device according to claim 11, wherein when the operation mode is changed to the heating mode, the operation mode display unit lights the heating mark and turns off the preheating mark.