WO2009125453A1

WO2009125453A1 - Induction heating cooking device

Info

Publication number: WO2009125453A1
Application number: PCT/JP2008/000920
Authority: WO
Inventors: 富永博; 小笠原史太佳; 磯田恵子
Original assignee: パナソニック株式会社
Priority date: 2008-04-09
Filing date: 2008-04-09
Publication date: 2009-10-15

Abstract

An induction heating cooking device which prevents false operations not intended by a user. The induction heating cooking device comprises a top board for placing an object to be heated, a heating coil disposed underneath the top board for induction-heating the object to be heated by generating a magnetic field, a controlling section for controlling an output of the heating coil, at least one operating switch (32a) provided on the top board, a light source (17) irradiating the operating switch, and a connecting terminal for electrically connecting the operating switch and the controlling section. The operating switch (32a) has a conductive detection section (18) for detecting a user's touch by a change in capacitance, and a conductive connection section (16) in contact with the connection terminal, wherein the connection section is so formed that it is directly connected to a part of a periphery of the detection section.

Description

Induction heating cooker

The present invention relates to an induction heating cooker provided with a capacitance type switch.

As described in Patent Document 1, a conventional induction heating cooker is provided with an operation unit for a user to operate heating of an object to be heated and a back surface of the operation unit, and the user's finger is an operation unit. A conductive detection unit that detects that the heating unit is touched, and a control unit that controls the heating coil based on the detection result of the detection unit. The detection part and the control part are electrically connected by connecting the conductive connection part and the control part, which are electrically connected to the detection part by a connection conductor, with a connection terminal. Moreover, the conventional induction heating cooking appliance illuminates the operation part from below with a backlight, and a transparent part that allows illumination light from the backlight to pass is provided around the operation part. Thereby, the position of the operation unit and the operation content indicated by the operation unit are shown to the user.
Japanese Patent No. 3741667

In the conventional induction heating cooker, since the connection part for making contact with the connection terminal is conductive, when the user's finger touches the connection part, it is the same as when the user's finger touches the detection part In addition, there is a problem that the capacitance of the connection portion is changed, and the control unit erroneously determines that the operation unit has been operated. In particular, the conventional induction heating cooker has a transparent part that allows illumination light from the backlight to pass around the operation part, so the connecting part is arranged outside the transparent part so as not to block the transparent part. It was. For this reason, the connecting portion is located away from the detecting portion, and the operation caused by touching the connecting portion is a malfunction that is not intended by the user.

This invention solves the said problem, and aims at providing the induction heating cooking appliance which prevents the malfunction which a user does not intend.

An induction heating cooker according to the present invention includes a top plate on which an object to be heated is placed, a heating coil that is provided below the top plate and generates a magnetic field to inductively heat the object to be heated, and an output of the heating coil A control unit that controls the operation switch, and further includes one or more operation switches provided on the top plate, a light source that irradiates the operation switch, the operation switch, and the control unit. And a connection terminal to be connected to. The operation switch includes a conductive detection unit that detects that a user has touched the battery by a change in capacitance, and a conductive connection unit that contacts the connection terminal. It is formed so as to be directly connected to a part of the outer edge.

Here, “light source” corresponds to “backlight 17” in the embodiment, and “control unit” corresponds to “printed wiring board 24” in the embodiment.

The operation switch may further include a frame display unit that displays a frame of the detection unit formed by cutting out a part of the detection unit.

The operation switch may further be provided with an operation content display unit formed by cutting out a part of the detection unit inside the frame display unit to indicate the content of the operation switch.

The induction heating cooker further includes a light-shielding unit that prevents light from the light source from being irradiated in front of the top plate on the outer periphery of the detection unit, and the inner edge of the light-shielding unit includes the outer edge of the frame display unit and the outer edge of the detection unit. The outer edge of the light shielding part may be outside the outer edge of the light source.

The connection part may be provided in the vertical direction from the detection part.

The detection unit may be provided above the light source, and a part of the connection unit may be provided outside the light source.

The light source may irradiate only operation switches that can be used in the operating state of the induction heating cooker.

According to the induction heating cooker of the present invention, it is possible to prevent the malfunction that is not intended by the user.

The top view which shows the top plate of embodiment of this invention A plan view showing operation switches provided on the top board Sectional view along the line AA in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Heating coil 11

Top plate

12a,

12b Heating part

13a, 13b Operation part 15a, 15b Display part 16 Connection part 17 Backlight 18

Detection part

19a, 19b, 19c, 19d Electrode 20 Frame display part 21 Operation content display part 22 Light-shielding part 23 Connection terminal 24 Printed wiring board 25 Main body 30a to 34a, 30b to 34b Operation switch

Hereinafter, embodiments of the present invention will be described with reference to the drawings. An induction heating cooker according to the present invention includes a main body including an inverter, a cooling fan, and the like, and a top unit attached to an upper portion of the main body. The top unit includes a top plate made of crystallized ceramic that transmits light, and a metal frame provided around the top plate. Below the top plate, at least one (two in FIG. 1) heating coil that generates a magnetic field and induction-heats an object to be heated is provided. The top plate provided in the induction heating cooker having the above-described configuration will be described below with reference to FIG.

FIG. 1 shows a top plate 11 of the induction heating cooker of the present invention. On the upper surface or the lower surface of the top plate 11,

heating units

12a and 12b indicating the place where the object to be heated is placed are displayed by printing. The

heating units

12a and 12b are displayed by forming a printed film in a circular shape at a position corresponding to the heating coil (the heating coil 10 in FIG. 3) provided below. In front of the top plate 11,

operation units

13a and 13b for setting the output of turning on / off of the heating coil 10 and display units 15a and 15b for displaying the operating states of the

heating units

12a and 12b are provided. . The

heating units

12a and 12b, the

operation units

13a and 13b, and the display units 15a and 15b are provided in the same number as the heating coil 10, respectively. Since the

heating units

12a and 12b, the

operation units

13a and 13b, and the display units 15a and 15b provided on the left and right have the same structure, the left heating unit 12a, the operation unit 13a, and the display unit 15a are representatively used. This will be described below.

The operation unit 13a includes a plurality of operation switches 30a to 34a. The operation switches 30a to 34a are capacitive switches that detect that the user's finger has touched. In FIG. 1, a plurality of operation switches 30a to 34a are a menu switch 34a, a heating switch 33a, a heating power adjustment switch 31a, a heating power adjustment switch 32a, and a timer switch 30a. The menu switch 34a is a switch for controlling the validity / invalidity of the operation of the other operation switches 30a to 33a, and is a switch that is lit first when the power is turned on. The heating switch 33a is a switch for starting / stopping heating of the object to be heated. The thermal power adjustment switch 31a is a switch for lowering the thermal power, and the thermal power gradually decreases each time the thermal power adjustment switch 31a is pressed. The thermal power adjustment switch 32a is a switch for increasing the thermal power, and the thermal power gradually increases every time the thermal power adjustment switch 32a is pressed. The timer switch 30a is a switch for setting the cooking time. For example, the cooking time increases every time the timer switch 30a is pressed, and the remaining cooking time set by the timer switch 30a is displayed on the display unit 15a.

In using such an induction heating cooker, after placing an object to be heated on the heating unit 12a corresponding to the heating coil 10, when the power is turned on, only the menu switch 34a is lit first. When the menu switch 34a is operated, the heating switch 33a is then turned on. When the heating switch 33a is operated and heating is started, the heating

power adjustment switches

31a and 32a and the timer switch 30a are turned on. In this way, only the usable operation switches are lit each time, and the user operates the operation switches 30a to 34a to perform desired cooking. At this time, the operating state of the heating unit 12a is displayed on the display unit 15a based on the operated operation switches 30a to 34a.

Next, the configuration of the operation switches 30a to 34a constituting the gist of the present invention will be described below with reference to FIGS. 2 and 3 on behalf of the operation switch 32a for adjusting the thermal power. FIG. 2 is a plan view showing the operation switch 32a showing a triangular shape for adjusting the heating power. FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2, and further shows a part of the top plate 11 and the heating coil 10.

The operation switch 32a includes a detection unit 18 that detects that the user's finger has touched, and a connection unit 16 that makes the conductive connection terminal 23 contact. The detection unit 18 includes a frame display unit 20 for indicating the approximate size and position of the outer periphery of the detection unit 18, and an operation content display unit 21 for indicating the operation content of the operation switch 32a. The detection unit 18 and the connection unit 16 are formed by printing electrodes 19 a to 19 d (hereinafter, the electrodes 19 a to 19 d are collectively referred to as “electrode 19”) on the back surface of the top plate 11. The operation content display unit 21 is formed by cutting out from the electrode 19.

The induction cooking device of the present invention has a backlight 17 below the detection unit 18. The light from the backlight 17 is emitted upward through the frame display unit 20 and the operation content display unit 21 so that the user can determine the content and position of the operation switch 32a. The backlight 17 is provided for each operation switch so that the plurality of operation switches 30a to 34a shown in FIG. 1 can be individually turned on. Only the operation switch that can be used in each operation state of the induction heating cooker is provided. Lights up. For example, the backlight 17 lights the operation switch 32a for adjusting the thermal power only during heating.

The induction heating cooker of the present invention has a light shielding part 22 for shielding light from the backlight 17 on the outer periphery of the detection part 18. The light shielding unit 22 is, for example, a black light absorbing film having a light transmittance of substantially zero. The light-shielding part 22 is positioned so that the position of the inner edge of the light-shielding part 22 is within the range of the width of the electrode 19a outside the frame display part 20, that is, inside the outer edge of the electrode 19a and outside the inner edge of the electrode 19a. The outer edge of the light shielding unit 22 is printed on the rear surface of the top plate 11 so that the outer edge is located outside the outer edge of the backlight 17.

The connection unit 16 is provided in a direction away from the user so as to be directly connected to a part of the outer edge of the detection unit 18. The external width dimension of the connection part 16 is smaller than that of the detection part 18 and is large enough to contact the connection terminal 23. The connection portion 16 is provided so that most of the connection portion 16 is outside the backlight 17 in order to prevent the backlight 17 and the connection terminal 23 from interfering with each other and the connection terminal 23 to reflect light. It is done.

Below the top plate 11, a high-frequency oscillation unit that applies a high-frequency voltage to the connection terminal 23 and a printed wiring board 24 that constitutes a circuit for detecting that a person has touched the electrode 19 are provided. When both ends of the connection terminal 23 come into contact with the printed wiring board 24 and the connection part 16, the detection unit 18 and the printed wiring board 24 are electrically connected. The backlight 17 is connected to the printed wiring board 24 by lead wires.

2 and 3, the operation switch 32a showing a triangular shape for adjusting the thermal power is taken as an example, but the operation switch showing characters such as “timer”, “heating”, “menu”, etc. in FIG. Similarly, 30a, 33a, and 34a are formed by cutting out the electrode 19 to form an operation content display unit 21 that is a character portion and a frame display unit 20 that indicates the approximate size and position of the outer periphery of the detection unit 18. Is done.

In the operation switches 30a to 34a configured as described above, when the user's finger touches the position of the top plate 11 facing the detection unit 18, the human body is equivalently connected to the ground by electric resistance and capacitance. As a result, the capacitance between the electrode 19 and the ground changes. Since the high-frequency voltage is supplied to the electrode 19 from the printed wiring board 24 through the connection terminal 23, the change in capacitance is transmitted to the printed wiring board 24 through the connection terminal 23, and the user It is determined that the operation switches 30a to 34a are operated. For example, the printed wiring board 24 reads a change in the magnitude of the voltage applied to the electrode 19 and determines the change in capacitance. Thereby, the control shown in the operation content display section 21 of the operation switches 30a to 34a is performed. Even if the electrode 19 is separated by the operation content display unit 21 or the frame display unit 20, the separated electrode 19 is electrically connected by the capacitance formed between the separated electrodes 19. Therefore, even when the user touches only the electrode 19b inside the frame display unit 20 that is not directly connected to the connection unit 16, for example, the electric signal is transmitted to the inside of the frame display unit 20 due to the capacitance. It is transmitted from the electrode 19b to the outer electrode 19a, and it can be detected that the user has touched it.

According to the present embodiment, since the frame display unit 20 is formed by being cut out from the electrode 19, it is not necessary to provide a conventional transparent unit for transmitting light on the outer peripheral side of the detection unit 18. . Thereby, the connection part 16 can be provided so that it may contact | connect the detection part 18, or very near. Therefore, when the user touches the connection unit 16, it is assumed that the user tries to touch the detection unit 18, and even if it is determined that the operation switches 30a to 34a are operated by touching the connection unit 16, It is possible to prevent the user from feeling uncomfortable.

Further, the connection unit 16 is arranged in a direction away from the user from the detection unit 18, and the external dimension of the connection unit 16 is smaller than the detection unit 18. Thus, it is possible to prevent the user from touching the connecting portion 16 by mistake as much as possible.

In addition, since the connection portion 16 is provided so that most of the connection portion 16 is outside the backlight 17 indicated by a broken line, the frame display portion 20 is affected by the shadow of the connection terminal 23 that is in contact with the connection portion 16. The occurrence of uneven brightness can be suppressed. Moreover, it can prevent that the connection terminal 23 reflects the light of the backlight 17, and can suppress that the brightness | luminance nonuniformity arises in the frame display part 20 or the operation content display part 21. FIG. Furthermore, since the connection terminal 23 is not disposed above the backlight 17, the gap between the main body 25 and the top plate 11 can be reduced, and the product of the induction heating cooker can be thinned. .

Conventionally, the connecting portion is separated from the detecting portion, and a part of the transparent portion (light emitting portion) is missing due to the connecting wire for connecting the detecting portion and the connecting portion. However, according to this embodiment, since the frame display unit 20 is formed by cutting out the electrode 19, a part of the frame display unit 20 is not lost and a complete rectangle can be represented. Therefore, it looks better than before.

Further, since the position on the inner edge side of the light shielding portion 22 only needs to be within the range of the width of the electrode 19a outside the frame display portion 20, printing of the light shielding portion 22 is slightly shifted from the outer edge side of the electrode 19a to the inner edge side. Even so, the light shielding portion 22 does not cover the frame display portion 20. That is, since there is a margin in the restriction of the position of the inner edge side of the light shielding part 22 by the width of the electrode 19a outside the frame display part 20, the width of the frame display part 20 is not increased due to the printing deviation of the light shielding part 22. Uniformity can be prevented.

Further, since the operation content display unit 21 is formed by cutting out the electrode 19, an effect of being easily understandable visually can be obtained in the light navigation in which only the usable operation switches 30a to 34a are turned on.

The electrodes 19a to 19d can be formed of, for example, a conductive paint coating film, a screen printing film, or a metal vapor deposition film. The electrodes 19a to 19c constituting the detection unit 18 and the electrode 19d constituting the connection unit 16 may be the same electrode, or may be electrodes formed separately. In the present embodiment, the electrodes 19a to 19d are provided on the back surface of the top plate 11. However, the electrodes 19a to 19d may be provided on the surface of the top plate 11 or provided on the front and back surfaces of the top plate 11. Also good.

It should be noted that the area of the detection unit 18 indicates that the user touched the area without the detection unit 18 being insufficient even if the frame display unit 20 and the operation content display unit 21 were formed by cutting out the electrode 19. Any size that can be detected is acceptable.

In this embodiment, the outer electrode 19a of the frame display unit 20 and the inner electrode 19b of the frame display unit 20 are completely separated by the frame display unit 20, but the outer electrode 19b is not separated completely. The frame display unit 20 may be provided so that the electrode 19a and a part of the inner electrode 19b are connected. Thereby, since the outer electrode 19a and the inner electrode 19b are reliably electrically connected, the reliability regarding detection can be improved. Similarly, the operation content display unit 21 may be provided so that the separated electrode 19c and part of the electrode 19b are connected to the operation content display unit 21.

Note that the operation switches 30a to 34a of the operation unit 13 illustrated in FIG. 1 are merely examples, and operation switches for instructing other operations may be provided with the same configuration as in this embodiment.

In the present embodiment, the top unit is composed of the top plate 11 and the metal frame, but the metal frame may not be provided.

The induction cooking device of the present invention has an effect of preventing a malfunction that is not intended by the user, and is useful as an induction heating cooking device for home use incorporated in a kitchen or the like.

Claims

A top plate on which the object to be heated is placed;
A heating coil that is provided below the top plate and generates a magnetic field to inductively heat an object to be heated;
A control unit for controlling the output of the heating coil;
An induction heating cooker having
The induction heating cooker
One or more operation switches provided on the top plate;
A light source for illuminating the operation switch;
A connection terminal for electrically connecting the operation switch and the control unit;
Have
The operation switch is
A conductive detection unit that detects that the user has touched by changing the capacitance;
A conductive connecting portion in contact with the connecting terminal;
Have
The induction cooking device according to claim 1, wherein the connecting portion is formed so as to be directly connected to a part of an outer edge of the detecting portion.
The induction heating cooker according to claim 1, wherein the operation switch further includes a frame display unit configured to display a frame of the detection unit, which is formed by cutting out a part of the detection unit.
3. The operation switch according to claim 2, wherein the operation switch further includes an operation content display unit formed by cutting out a part of the detection unit to indicate the content of the operation switch inside the frame display unit. Induction heating cooker.
Further provided on the outer periphery of the detection unit is a light blocking unit that prevents light from the light source from being irradiated in front of the top plate,
The inner edge of the light shielding part is in a range between the outer edge of the frame display part and the outer edge of the detection part,
The induction heating cooker according to claim 2, wherein an outer edge of the light-shielding portion is outside an outer edge of the light source.
The induction heating cooker according to claim 1, wherein the connection portion is provided in a saddle direction from the detection portion.
The induction heating cooker according to claim 1, wherein the detection unit is provided above the light source, and a part of the connection unit is provided outside the light source.
The induction heating cooker according to claim 1, wherein the light source irradiates only an operation switch that can be used in an operation state of the induction heating cooker.