JP2001326064A - Induction heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display a state of heating clearly on a top plate corresponding to a heating coil with continuous figure. SOLUTION: A heating coil 12 is installed under a top plate 6 corresponding to a heating part 7 of the top plate 6 placing a cooking pot 11, and a circular light guide body 13 with inner diameter slightly bigger than outer the diameter of the heating coil 12 is arranged at the part lower than the heating coil 12, and light is inputted to the light conducting body by a lighting bulb 14. As the light inputted to the light conducting body 13 illuminates at whole range of circumferential part of the light guide body from upper part toward the top plate 6, a continuous circular pattern is enabled to illuminate on the top plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating cooker, and more particularly to a display on a top plate.

[0002]

2. Description of the Related Art In an induction heating cooker, a high-frequency current is applied to a heating coil to generate a high-frequency magnetic field, and a pan (load) magnetically coupled to the heating coil generates Joule heat due to an eddy current to generate heat in the pan itself. It is a cooker that performs cooking by letting it cook. Therefore, there is a problem that the heating unit cannot be visually recognized, unlike a gas cooker in which a flame is visible or an electric heater in which the heating unit glows red.

[0003] In order to solve this problem, for example, there is one disclosed in Japanese Patent Publication No. 2903561. In FIG. 5, a heating pot 2 provided below the top plate 1 is heated by induction heating, and a light bulb 3 disposed around the heating coil 2.
Then, at the same time as the heating operation, the bulb 3 arranged around the heating coil 2 is turned on to indicate the heating range, and a substance emitting light by receiving light is attached to the lower surface of the iron plate provided on the upper surface of the main body, and the pot is placed. It is disclosed that when a heating operation is started, a light bulb 3 provided in the center of a heating coil emits light, and the light is subjected to secondary emission to display a circle 4 as shown in FIG. 6 on a top plate. ing.

In Japanese Patent Application Laid-Open No. Hei 7-313279, a plurality of light emitting diodes for heating display are provided annularly on the outer periphery of the heating coil and a light emitting diode for heat power display is provided near the outside thereof. It is described that when heated, a light emitting diode for heating display shines to indicate the heating state.

[0005]

However, in the above-mentioned conventional configuration, a light emitting means, for example, a light bulb 3 is arranged around the heating coil 2, so that the heating section of the heating section corresponding to the heating coil 2 is displayed. Several light bulbs were needed.
In addition, there is a problem that if the number of light bulbs is limited, it is difficult to understand the whole because the display is a point display.

Further, in the display method using secondary light emission, a figure such as a circle can be drawn relatively easily. However, the light emission efficiency of secondary light emission is poor and the display is thin and difficult to see. It is difficult to draw a clear figure due to the directivity and mounting variation of the light bulb because the light of the arranged light bulb 3 is used, and the stability is poor because the secondary luminescent material is provided under the high temperature top plate. However, it has not been put to practical use yet.

An object of the present invention is to solve the conventional problem and to provide an induction heating cooker capable of clearly displaying the vicinity of a heating range of a heating unit corresponding to a heating coil with a few light sources.

[0008]

In order to solve the above-mentioned problems, the present invention has a structure in which a light guide is provided which surrounds a heating coil provided corresponding to a heating section on a top plate. The light guide was provided with a light reflecting layer other than the upper portion for emitting light, and was provided with a gradient over the entire circumference to emit light entering from one end in the direction of the top plate over the entire circumference of the heating coil. As a result, light is emitted over the entire circumference, so that the heating section can be clearly displayed on the top plate.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 is characterized in that a translucent top plate provided on the upper surface of a main body case and a cooking container provided on the top plate are placed on the top plate by induction heating. A heating unit for heating, a heating coil provided below the top plate corresponding to the heating unit, a light guide provided on an outer peripheral portion of the heating coil, and a light source for emitting light to the light guide. The light guide receives light from the light source and emits the light in the direction of the top plate over a part or the entire circumference of the heating coil.

[0010] Then, since continuous clear graphics are displayed on the top plate, the heating state can be easily confirmed.

The invention according to claim 2 is configured such that the light guide has a gradient such that the distance between the upper part and the lower part of the light guide decreases as the distance from the light source increases.

[0012] Since the straight light from the light source reaches far, the entire light guide uniformly emits light.

Further, the invention according to claim 3 has a structure in which a light diffuse reflection layer is provided below the light guide by chemical or mechanical means.

The invention according to claim 4 has a structure in which a specular reflection layer is provided below the light guide by vapor deposition, painting, or attachment of a reflector.

The invention according to claim 5 has a configuration in which a serrated prism is provided below the light guide.

Since the reflected light from the lower part of the light guide reaches the upper part uniformly, the display is not mottled.

The invention according to claim 6 has a structure in which a layer having a smaller refractive index of light than the light guide is provided in addition to the upper part of the light guide where light is emitted.

Since there is little loss due to light leakage, a clear figure can be drawn on the top plate.

Further, in the invention according to claim 7, the reflectance of the light reflecting layer provided below the light guide is different for each part.

Then, figures with different shades can be drawn on the top plate.

Further, the invention according to claim 8 has a configuration in which the outer shape of the light guide is formed in a donut shape.

The heating section can be clearly displayed for the circular heating coil.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

Note that the outer peripheral portion of the heating coil in the present invention means that the light guide is located on the outer periphery of the heating coil on the projection surface, and does not specify the positional relationship in the height direction. In this embodiment, the light guide is described as being below the heating coil.

FIG. 2 is a perspective view of an induction cooking device used in the present invention. As shown in FIG. 2, a translucent top plate 6 is provided on the upper surface of the main body case 5. The top plate 6 is provided with a heating section 7 for heating the pot by induction heating and cooking the object to be cooked, and a radiant heater 8 for cooking using a pot that cannot be used for induction heating. A roaster 9 and an operation unit 10 are provided on a front side surface of the main body case 5.

FIG. 1 is a cross-sectional view of an essential part showing a cross section of one of the heating coils 7 of FIG. In the figure, a cooking pot 11 is placed on a heating section 7 of a top plate 6. In order to heat the cooking pot 11, a heating coil 12 is provided in a lower portion of the top plate 6, that is, at a position corresponding to the cooking pot. Further, a light guide 13 is provided below the heating coil 12. By making the size of the light guide 13 large enough to surround the outer peripheral portion of the heating coil 12, light emission from the light guide 13 reaches the top plate 6 without being obstructed by the heating coil,
The range of the heating unit 7 can be clearly displayed on the top plate 6. As the light guide, a material having good light transmission performance, such as an acrylic resin, a polycarbonate resin, or glass, is used. A light source 14 includes a light bulb, an LED (semiconductor light emitting element), and the like, and light emitted from the light source propagates through the light guide. Reference numeral 15 denotes a control unit that controls the heating power for cooking and the blinking of the light source 14.

FIG. 3 is a plan view showing the structure of the light emitting means in which one light guide and one light source, which are a feature of the present invention, are paired.

In FIG. 3, the light guide 13 has a donut shape corresponding to the circular heating coil 12, and the inner diameter of the light guide 13 is slightly larger than the outer shape of the heating coil 12.
The cross section of the light guide in a direction perpendicular to the optical path may be a circle, a square, or a shape similar thereto. And such a light guide is generally easily obtained by resin molding.

A light source chamber 16 is located at a light input position of the light guide 13.
In this embodiment, one light bulb 14 is provided. The light source chamber 16 is surrounded by a reflector so that light is not emitted in directions other than the direction of the light guide 13. Light emitted from the light bulb 14 propagates through the light guide 13 while repeating straight or reflection. In the course of this propagation, light is emitted in the direction of the top 6 and its intensity is attenuated. Thus, the light is transmitted through the light guide 13.
The light is emitted in the direction of the top plate 6 while propagating through the top plate 6, and a figure having the same shape as the top surface of the light guide 13 is displayed on the top plate 6. In FIG. 3, a circle is displayed.

If light is emitted in directions other than the direction of the top plate 6 during propagation of light, the intensity of the light is attenuated. Layers are provided. The reflective layer may be a metal foil or plate of aluminum, stainless steel, or the like, or may be formed by vapor deposition or sputtering of a metal or metal oxide. Further, there is a method of forming a reflective film by painting or a chemical method. In any case, the top plate 6 can be provided by providing the reflection film.
Light attenuation in the direction can be suppressed.

FIG. 4 is a developed view of a light guide obtained by resin molding for explaining the structure of the light guide for making the light emission in the direction of the top plate 6 uniform. For example, FIG. The light guide 13 having a simple shape is formed into a round shape. As shown in the figure, the light guide 13 has a shape in which the upper part 13a that emits light is horizontal and the lower part 13b that reflects light has a gradient. That is, the lower part 13b that reflects light and the upper part 13 that emits light
The distance from “a” becomes shorter as the distance from the light source 14 increases. Thus, light incident from the p short distance from the top 13a is directed toward the reflected upper 13a strikes the bottom 13b at a distance l ₂ away from the light source 14. The light distance from the top is incident from longer position q is toward the reflected upper 13a strikes the bottom 13b at a distance l ₁ closer to the light source 14. By doing so, the upper part 13a of the light guide 13 is formed.
And uniform light intensity can be drawn on the top plate 6.

Next, a method of providing a reflective layer on the lower portion 13b of the light guide will be described. As a method of providing the irregular reflection layer among the reflection layers, the surface of the lower portion 13b is mechanically polished to provide irregularities. Alternatively, it may be chemically etched. At this time, when it is difficult to obtain an uneven surface by etching, it is preferable to use masking in combination. Further, when the light guide 13 is formed by resin molding, fine irregularities may be formed on the lower portion 13b.
Further, the same or different material may be attached to the surface of the lower portion 13b by spraying or the like to form irregularities. When a metal powder or the like is adhered to the uneven surface thus obtained, an irregular reflection layer is obtained. When light is incident on the irregular reflection layer, the light is diffusely reflected in four directions, so that it is easy to obtain uniform light emission.

The mirror reflection layer may be provided by a method of providing a layer of metal powder on the lower part 13b of the light guide by vapor deposition, sputtering or painting as described above, or by attaching a metal foil or plate. Can be.
Such a specular reflection layer is particularly effective when the lower portion 13b is provided with a gradient, and can uniformly emit light from the upper portion 13a.

When there is a gradient in the lower part 13b, a large number of continuous prisms are provided on the surface of the lower part 13b in a sawtooth shape during resin molding, and the incident light is reflected by this prism to form the upper part 13b.
Even when light is emitted from 3a, light can be emitted uniformly.

Further, as a method of providing a light reflecting layer, the light guide 13 may be covered with a substance having a smaller refractive index than the light of the light guide 13 and totally reflected at an interface between the two. .

In the above-described embodiment, the case has been described in which the light incident from the light source is intended to be uniformly emitted over the entire light guide 13. However, when a shaded figure is to be displayed on the top plate 6, the light guide is required. In order to partially change the reflectance of the lower part 13b of the body 13, the roughness of the lower part 13b is changed,
If the lower portion 13b has a gradient, the gradient can be changed or displayed non-uniformly.

In the case where the outer circumference of the heating coil is long and the luminous intensity of one light source is low at a position distant from the light source, one pair of the light source and the semicircular light guide is used. do it. The number of sets may be increased as needed.

In the above-described embodiment, the light guide has a circular outer shape. However, it is needless to say that the light guide may have a square shape or a shape similar to a circle or a square as described above. However, since the heating coil is generally circular, it is preferable that the light guide be circular, because the position of the heating coil, that is, the position of the heating section is clear and the stability is excellent.

Although the present invention has been described with respect to the case where light is emitted over the entire circumference of the heating coil, it may be a part of the heating coil such as a half circumference if necessary.

As described above, according to this embodiment, it is possible to draw a continuous, clear figure on the top plate, not on dots or lines. In addition, since the number of light sources used is minimal, the cost can be reduced.

[0041]

According to the present invention, since the light source and the light guide which receives the light from the light source and emits light over a part or the whole of the outer periphery of the heating coil, a continuous clear figure on the top plate can be formed. It can be displayed and the heating state can be easily visually grasped. Moreover, since the number of light sources is minimized, the productivity and cost can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an induction heating cooker according to one embodiment of the present invention.

FIG. 2 is an external perspective view of an induction heating cooker.

FIG. 3 is a plan view of a light emitting means of the induction heating cooker according to one embodiment of the present invention.

FIG. 4 is a developed view of a light guide of the induction heating cooker.

FIG. 5 is a sectional view of a main part of a conventional induction heating cooker.

FIG. 6 is a diagram showing an example of a display figure of a conventional induction heating cooker.

[Explanation of symbols]

 5 Body case 6 Top plate 7 Heating part 12 Heating coil 13 Light guide 14 Light source

Claims (8)

[Claims] 1. A translucent top plate provided on an upper surface of a main body case, a heating unit for mounting a heating cooking container provided on the top plate and heating by induction heating, and a lower portion of the top plate A heating coil provided corresponding to the heating unit, a light guide provided on an outer peripheral portion of the heating coil, and a light source for emitting light to the light guide, wherein the light guide is a light source of the light source. , And emits the light in the direction of the top plate over a part or the entire circumference of the heating coil. 2. The induction heating cooker according to claim 1, wherein the light guide has a gradient such that a distance between an upper portion and a lower portion of the light guide decreases as the distance from the light source increases. 3. The induction heating cooker according to claim 1, wherein a light irregular reflection layer is provided below the light guide by chemical or mechanical means. 4. The induction heating cooker according to claim 1, wherein a specular reflection layer is provided below the light guide by vapor deposition, painting, or attachment of a reflection plate. 5. The induction heating cooker according to claim 1, wherein a serrated prism is provided below the light guide. 6. The induction heating cooker according to claim 1, wherein a layer having a smaller refractive index of light than that of the light guide is provided in addition to an upper portion of the light guide where light is emitted. 7. The induction heating cooker according to claim 1, wherein the reflectance of the light reflection layer provided below the light guide is different for each portion. 8. The induction heating cooker according to claim 1, wherein the outer shape of the light guide has a donut shape.