Patent Description:
In homes and restaurants, cooking devices using various heating methods to heat food or other items (hereinafter, "food") are being used. Conventionally, gas ranges using gas as fuel have been widely used. However, in recent years, there has been an increase in devices for heating a cooking vessel containing food, such as a pot or container, using electricity without using gas.

A scheme of heating a cooking vessel containing food using electricity is divided into a resistive heating type and an induction heating type. In the electrical resistive heating method, heat generated when current flows through a metal resistance wire or a non-metallic heating element, such as silicon carbide, is transmitted to the cooking vessel through radiation or conduction, thereby heating the cooking vessel. In the induction heating method, when high-frequency power of a predetermined magnitude is applied to the working coil, an eddy current is generated in the cooking vessel made of a metal using a magnetic field generated around the working coil so that the cooking vessel itself is heated.

The principle of the induction heating scheme is as follows. First, as power is applied to the induction heating device, a high-frequency voltage of a predetermined magnitude is applied to the working coil. Accordingly, an inductive magnetic field is generated around the working coil disposed in the induction heating device. When the magnetic-flux of the inductive magnetic field thus generated passes through a bottom of the cooking vessel containing metal positioned on the induction heating device, an eddy current is generated inside the bottom of the cooking vessel. When the resulting eddy current flows in the bottom of the cooking vessel, the cooking vessel itself is heated.

When the induction heating device is used, a plate of the induction heating device is not heated but only the cooking vessel itself is heated. Thus, when the cooking vessel is lifted up from the plate of the induction heating device, the inductive magnetic field around the coil is extinguished, and thus, the cooking vessel immediately ceases to be heated. Further, as the working coil in the induction heating device is not heated, a temperature of the plate is kept at a relatively low temperature even during cooking, which is advantageous for safety.

Furthermore, as the induction heating device heats only the cooking vessel itself by induction heating, the induction heating device has a more energy-efficient advantage over the gas-range or resistance heating based device. Another advantage of such an induction heating device is that it may heat the cooking vessel faster than other heating scheme based devices. The higher the output of the induction heating device, the faster the cooking vessel may be heated.

<FIG> is a perspective view of a related art induction heating device. As shown in <FIG>, an induction heating device <NUM> includes a casing <NUM>, and a cover plate <NUM> that seals the casing <NUM>. In a space formed inside the casing <NUM>, one or more working coils 114a and 114b having a circular shape are disposed.

The cover plate <NUM> coupled with the casing <NUM> includes a plate <NUM> on which a cooking vessel, such as a pot or container to be heated, is placed. When the cover plate <NUM> is engaged with the casing <NUM>, heating regions 104a and 104b having positions respectively corresponding to positions of the working coils 114a and 114b disposed inside the casing <NUM> may be defined in the plate <NUM>. The heating regions 104a and 104b may have a circular shape corresponding to shapes of the working coils 114a and 114b.

With power supplied to the induction heating device <NUM>, the user places the cooking vessel on one of the heating regions 104a and 104b. Then, the user performs a manipulation to select the heating region, and a manipulation to select a heating power of the selected heating region via a manipulation interface (not shown) formed on the plate <NUM>.

After the manipulation of the user, it is confirmed via a cooking vessel sensing operation of the induction heating device <NUM> that the cooking vessel having an induction heating property is placed on the selected one of the heating regions 104a and 104b. Thus, current is applied to the working coil corresponding to the selected heating region by a control unit or controller (not shown) and a power supply (not shown). In this way, an inductive magnetic field between the cooking vessel and the working coil is formed such that the cooking vessel begins to heat up.

However, when using the conventional induction heating device <NUM> having the configuration shown in <FIG>, the cooking vessel must be placed on one of the heating regions 104a and 104b so that a top surface of the one of the heating regions 104a and 104b defined in the plate <NUM> and a bottom surface of the cooking vessel conform or correspond with each other. When the top surface of the one of the heating regions 104a and 104b and the bottom surface of the cooking vessel do not conform or correspond with each other, the inductive magnetic field between the working coils 114a and 114b disposed below the heating regions 104a and 104b and the cooking vessel is weakened. This makes it difficult to reach the user-set heating power and hence a power efficiency of the induction heating device <NUM> is lowered. Further, when the top surface of the one of the heating regions 104a and 104b and the bottom surface of the cooking vessel do not conform or correspond with each other, the inductive magnetic field may fail to occur be-tween the working coils 114a and 114b disposed below the heating regions 104a and 104b and the cooking vessel. The cooking vessel may not be heated up.

Further, as the heating regions 104a and 104b of the related art induction heating device <NUM> shown in <FIG> generally have a circular shape, the shape of the cooking vessel to be placed on the regions is also limited to a circular shape.

In order to overcome the above-mentioned disadvantages of the related art induction heating device <NUM>, recently, an induction heating device employing a free zone or zone free scheme has been introduced.

<FIG> is a perspective view of a related art induction heating device employing a free zone scheme. Referring to <FIG>, an induction heating device <NUM> having the free zone scheme includes a casing <NUM> and a cover plate <NUM> that seals the casing <NUM>. The cover plate <NUM> includes a plate <NUM>. A heating region <NUM> for receiving a cooking vessel, such as a pot or container to be heated, may be defined in the plate <NUM>.

As shown in <FIG>, the heating region <NUM> of the induction heating device <NUM> with the free zone scheme is formed in a square shape, which covers most of an area of the plate <NUM>. Accordingly, even when the user places the cooking vessel on any location in the heating region <NUM>, the heating of the cooking vessel may be realized.

Therefore, when compared with the conventional induction heating device <NUM> shown in <FIG>, the user does not need to conform or correspond a bottom surface of the cooking vessel to a top surface of heating regions 104a and 104b, thereby increasing convenience, when using the configuration of <FIG>. Further, the induction heating device is less likely to be power-inefficient or less likely to fail to heat the cooking vessel, which is otherwise the case when the user places the cooking vessel in the wrong position.

In the casing <NUM> of the induction heating device <NUM> employing the free zone scheme shown in <FIG>, one or more working coils 212a, 212b, and 212c may be disposed to correspond to the heating region <NUM>. As shown in <FIG>, each of the working coils 212a, 212b, and 212c of the induction heating device <NUM> employing the free zone scheme has an elliptical shape having a major axis and a minor axis. Generally, each of the working coils 212a, 212b, and 212c may be fabricated by pressing and deforming one side of each of the circular working coils 114a and 114b shown in <FIG>.

After placing the cooking vessel to be heated on or at any location within the heating region <NUM> of the induction heating device <NUM> having such a configuration, the user may select a heating power of the heating region via manipulation of a manipulation interface (not shown) formed in or on the plate <NUM>. When it is confirmed that the cooking vessel having an induction heating property is loaded on the heating region <NUM> via a cooking vessel sensing operation of the induction heating device <NUM>, current is applied to one of the working coils 212a, 212b and 212c, which is located at a position corresponding to a position of the cooking vessel placed on the heating region <NUM>. This current application is performed by a control unit or controller (not shown) and a power supply (not shown). This results in an inductive magnetic field between the cooking vessel and the working coil, and the cooking vessel begins to heat up. However, as shown in <FIG>, between the working coils 212a, 212b, and 212c included in the conventional induction heating device <NUM> employing the free zone scheme, and between the working coils 212a, 212b, and 212c and walls of the casing <NUM>, non-coil regions 220a to <NUM> corresponding to the heating region <NUM> but not corresponding to the working coils are present.

When the cooking vessel to be heated is placed on or at positions corresponding to the non-coil regions 220a to <NUM>, the inductive magnetic field between the working coils 212a, 212b, and 212c and the cooking vessel is weakened, and thus, the power efficiency is lowered. Further, there is a problem of increased heating time and cooking time of the cooking vessel.

<CIT> describes an induction heating electric hob consisting of a glass ceramic hob, below which is disposed an inductor connected to a converter connected to the mains. This inductor consists of a spiral winding plane. The plate for supporting the utensils is based on a transparent glass-ceramic mounted on an insulating support having a housing inside which is disposed the inductor. Between the support and the plate is disposed an intermediate complex consisting for example of a mica sheet covered with a layer of glass fabric. The elements of decoration or marking of the hob are made below the plate.

<CIT> relates to an induction cooking top comprising at least three windings having the shape of an elongated ring, wherein the longitudinal axes of such windings are arranged in at least two different directions in a manner such that the projections of the longitudinal axes on a plane define a closed area in that plane.

<CIT> relates to an induction cooker that is constituted of a top plate on which the object to be heated is loaded, a heating coil provided at a lower side of the top plate for heating the object to be heated by induction and a high-frequency power source for driving the heating coil. By installing the heating coil, a coil axis becomes parallel with the top plate, magnetic flux in one direction is made to intersect the bottom surface of the object to be heated.

This Summary is not intended to identify all key features or essential features of the claimed subject matter, nor is it intended to be used alone as an aid in determining the scope of the claimed subject matter.

The present disclosure is to provide a coil assembly and an inductively-heating device including the coil assembly, in which the non-coil regions corresponding to the heating-region but not corresponding to the working coils may be absent between the working coils included in the inductively-heating device employing the free zone scheme, and be-tween the working coils and the walls of the casing, thereby to prevent reduction of the power efficiency based on the placed position of the cooking vessel, and thus, to prevent the heating time and the cooking time from increasing.

The purposes of the present disclosure are not limited to the above-mentioned purposes. Other purposes and advantages of the present disclosure, as not mentioned above, may be under-stood from the following descriptions and more clearly understood from the embodiments of the present disclosure. Further, it will be readily appreciated that the objects and advantages of the pre-sent disclosure may be realized by features and combinations thereof as disclosed in the claims.

The object is solved by the features of the independent claim.

The present disclosure provides an inductively-heating device with a new structure to over-come the disadvantages of the conventional inductively-heating device with the free zone scheme. The coil assembly included in the inductively-heating device according to one embodiment of the present disclosure includes a coil frame having a shape corresponding to the shape of the heating-region defined in the loading plate. Further, the working coil included in the coil assembly according to one embodiment of the present disclosure extends alternately in between opposite first direction and second direction, rather than extending circularly as in the conventional working coil. The over-all arrangement shape of the working coil having such an alternating arrangement has a rectangular shape instead of a circular shape or an elliptic shape as in the prior art.

Thus, the inductively-heating device employing the free zone scheme, including the coil assembly according to the present disclosure, provides a constant heating power regardless of where the user places the cooking vessel on the heating-region. This may prevent reduction of the power efficiency based on the placed position of the cooking vessel, and thus, to prevent the heating time and the cooking time from increasing, which may otherwise occur in the conventional inductively-heating device.

In a first aspect of the present disclosure, there is provided a coil assembly comprising: a coil frame; a coil accommodation structure disposed on a first face of the frame; and a working coil extending in the coil accommodation structure, wherein a direction of the extension of the working coil is alternated between opposite first and second directions.

In one embodiment of the coil assembly, the coil accommodation structure includes first and second accommodation structures.

In one embodiment, the working coil includes first and second working coils, wherein the first working coil extends in the first accommodation structure, while the second working coil in the second accommodation structure.

In one embodiment, a magnetic-flux generation region is defined between the first accommodation structure and second accommodation structure.

In one embodiment of the coil assembly, the coil accommodation structure has a coil-receiving groove defined therein for receiving the working coil therein.

In one embodiment the working coil extends substantially in a straight line in the at least one coil accommodation structure.

The coil assembly further comprises first and second coil-holding structures, wherein first and second coil-holding structures extend respectively along both opposing lateral elongate sides of the coil accommodation structure, wherein the working coil turns around the first coil-holding structure such that the extension direction of the working coil changes from the first direction to the second direction, wherein the working coil turns around the second coil-holding structure such that the extension direction of the working coil changes from the second direction to the first direction.

In one embodiment of the coil assembly, a first intersecting space is defined between the coil accommodation structure and first coil-holding structure, while a second intersecting space is defined between the coil accommodation structure and second coil-holding structure.

In one embodiment of the coil assembly, the working coil has a rectangular-shaped cross-section.

In one embodiment of the coil assembly, the coil assembly further comprises at least one magnetic core disposed on a second face of the coil frame, wherein the first face is opposite to the second face.

In a second aspect of the present disclosure, there is provided an inductively-heating device comprising: a cover plate including a loading plate, wherein a heating-region is de-fined in the loading plate; a coil assembly disposed below the loading plate, wherein the coil assembly vertically overlaps the heating-region; and a casing housing the coil assembly, wherein the casing is blocked at a top thereof by the cover plate, wherein the coil assembly comprises: a coil frame; a coil accommodation structure disposed on a first face of the frame; and a working
coil extending in the coil accommodation structure, wherein a direction of the extension of the working coil is alternated be-tween opposite first and second directions.

In one embodiment of the inductively-heating device, the coil accommodation structure includes first and second accommodation structures, wherein the working coil includes first and second working coils, wherein the first working coil extends in the first accommodation structure, while the second working coil in the second accommodation structure, wherein a magnetic-flux generation region is defined between the first accommodation structure and second accommodation structure.

In one embodiment of the inductively-heating device, the coil accommodation structure has a coil-receiving groove defined therein for receiving the working coil therein.

In one embodiment of the inductively-heating device, the coil assembly further comprises first and second coil-holding structures, wherein first and second coil-holding structures ex-tend respectively along both opposing lateral elongate sides of the coil accommodation structure, wherein the working coil turns around the first coil-holding structure such that the extension direction of the working coil changes from the first direction to the second direction, wherein the working coil turns around the second coil-holding structure such that the extension direction of the working coil changes from the second direction to the first direction.

In one embodiment of the inductively-heating device, a first intersecting space is de-fined between the coil accommodation structure and first coil-holding structure, while a second intersecting space is defined between the coil accommodation structure and second coil-holding structure.

In one embodiment of the inductively-heating device, the working coil has a rectangular-shaped cross-section.

In one embodiment of the inductively-heating device, the coil assembly further comprises at least one magnetic core disposed on a second face of the coil frame, wherein the first face is opposite to the second face.

In accordance with the present disclosure, the non-coil regions corresponding to the heating-region but not corresponding to the working coils may be absent between the working coils included in the inductively-heating device employing the free zone scheme, and between the working coils and the walls of the casing, thereby to prevent reduction of the power efficiency based on the placed position of the cooking vessel, and thus, to prevent the heating time and the cooking time from increasing.

For simplicity and clarity of illustration, elements in the figures are not necessarily drawn to scale. The same reference numbers in different figures denote the same or similar elements, and as such perform similar functionality. Also, descriptions and details of well-known steps and elements are omitted for simplicity of the description. Further, in the following detailed description of embodiments, numerous specific details are set forth in order to provide a thorough understanding. However, it will be understood that embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects.

Examples of various embodiments are illustrated and described further below. It will be understood that the description herein is not intended to limit the claims to the specific embodiments described. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the scope as defined by the appended claims.

Thus, a first element, component, region, layer or section described below could be termed a second element, component, region, layer or section, without departing from the scope.

It will be understood that when an element or layer is referred to as being "connected to", or "coupled to" another element or layer, it can be directly on, connected to, or coupled to the other element or layer, or one or more intervening elements or layers may be present. In addition, it will also be understood that when an element or layer is referred to as being "between" two elements or layers, it can be the only element or layer between the two elements or layers, or one or more intervening elements or layers may also be present.

Spatially relative terms, such as "beneath," "below," "lower," "under," "above," "upper," and the like, may be used herein for ease of explanation to describe one element or feature's relationship to another elements or features as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the induction heating device in use or in operation, in addition to the orientation depicted in the figures. For example, if the induction heating device in the figures is turned over, elements described as "below" or "beneath" or "under" other elements or features would then be oriented "above" the other elements or features. Thus, the example terms "below" and "under" can encompass both an orientation of above and below. The induction heating device may be otherwise oriented for example, rotated <NUM> degrees or at other orientations, and the spatially relative descriptors used herein should be interpreted accordingly.

It will be further understood that the terms "comprises", "comprising", "includes", and "including" when used in this specification, specify the presence of the stated features, integers, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, operations, elements, components, and/or portions thereof. Expression such as "at least one of" when preceding a list of elements may modify the entire list of elements and may not modify the individual elements of the list.

It will be further understood that terms, such as those de-fined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In the following description, numerous specific details are set forth in order to provide a thorough understanding. The embodiments may be practiced without some or all of these specific details. In other instances, well-known process structures and/or processes have not been described in detail in order not to unnecessarily obscure the embodiments.

<FIG> is a top perspective view of a coil frame included in a coil assembly according to an embodiment. <FIG> is a bottom perspective view of the coil frame included in the coil assembly according to an embodiment.

Referring to the drawings, a coil assembly <NUM> according to an embodiment may include a coil frame <NUM> that supports a working coil. The coil frame <NUM> shown in the figure has a rectangular shape. The shape may correspond to a shape of a heating region defined in a plate of an induction heating device as described hereinafter. However, a shape of the coil frame <NUM> may vary depending on the embodiment.

On the coil frame <NUM>, there are coil accommodation structures constructed for accommodating working coils, that is, a first coil accommodation structure 304a and a second coil accommodation structure 304b. Each of the first coil accommodation structure 304a and the second coil accommodation structure 304b has at least one coil receiving groove defined therein for accommodating a corresponding working coil.

As described below, each of the first and second working coils is alternately turned in a first direction (from X1 to X2) or a second direction (from X2 to X1) and along the coil receiving groove defined within each of the first coil accommodation structure 304a and the second coil accommodation structure 304b. Thus, an arrangement shape of the working coil extending in the first coil accommodation structure 304a is substantially similar to a contour shape of the first coil accommodation structure 304a. Further, an arrangement shape of the working coil extending in the second coil accommodation structure 304b is substantially similar to a contour shape of the second coil accommodation structure 304b. This shape is square in this example. However, embodiments are not limited thereto. The contour shape of each of the first coil accommodation structure 304a and the second coil accommodation structure 304b, and the arrangement shape of the working coils may vary depending on the embodiment. Further, a magnetic flux generation region <NUM> may be defined between the first coil accommodation structure 304a and the second coil accommodation structure 304b. When a current is applied to the working coils accommodated in the first coil accommodation structure 304a and the second coil accommodation structure 304b, magnetic flux is generated in the magnetic flux generation region <NUM> and flows therein.

As shown in the figure, the coil receiving groove is not formed in the magnetic flux generation region <NUM>, and thus, the working coil is not disposed therein. An area occupied by the magnetic flux generation region <NUM> on the coil frame <NUM> may vary depending on a power requirement based on a specification of the induction heating device, a length of the working coil, and an area of each of the first coil accommodation structure 304a and the second coil accommodation structure 304b.

Along both sides of the first coil accommodation structure 304a, the second coil accommodation structure 304b, and the magnetic flux generation region <NUM>, coil holding structures, that is, a first coil-holding structure 308a and a second coil holding structure 308b extend respectively. As shown in the drawing, the first coil holding structure 308a and the second coil holding structure 308b extend in a direction (Y1↔Y2) that intersects the extending direction of the working coil, that is, the first direction (from X1 to X2) or the second direction (from X2 to X1).

When the working coils extend in and along the first coil accommodation structure 304a and the second coil accommodation structure 304b, the first coil holding structure 308a and the second coil holding structure 308b may change the direction of the working coil from the first direction (X1 ---> X2) to the second direction (X2 → X1) or change the second direction (X2 → X1) to the first direction (X1 -> X2). A first intersecting space 310a and a second intersecting space 310b may be defined between the first coil accommodation structure 304a, the second coil accommodation structure 304b, the magnetic flux generation region <NUM>, and the first coil holding structure 308a and the second coil holding structure 308b, respectively. The first intersecting space 310a may be defined between the first and second coil accommodation structures 304a and 304b and the first coil holding structure 308a. The working coil extending from the first and second coil accommodation structures 304a and 304b toward the first coil holding structure 308a may pass through the first intersecting space 310a. The second intersecting space 310b may be defined be-tween the first and second coil accommodation structures 304a and 304b and the second coil holding structure 308b. The working coil extending from the first and second coil accommodation structures 304a and 304b toward the second coil holding structure 308b may pass through the second intersecting space 310b.

Further, referring to <FIG>, on a bottom surface of the coil frame <NUM>, one or more magnetic cores 320a to <NUM> may be disposed. When current is applied to the working coil so that an inductive magnetic field is formed between the coil and the cooking vessel, the magnetic cores 320a to <NUM> act to increase a magnetic flux density. More specifically, the magnetic cores 320a to <NUM> may be disposed on the bottom surface of the coil frame <NUM> in a region 314a corresponding to the first coil accommodation structure 304a, and in a region 314b corresponding to the second coil accommodation structure 304b.

In the figure, four magnetic cores are arranged in each region. However, a number, magnitude, and arrangement of the magnetic cores disposed in each region may vary depending on the embodiment. Further, in the drawing, the magnetic cores are not arranged in region <NUM> corresponding to the magnetic flux generation region <NUM> of the coil frame <NUM>. However, according to an embodiment, the magnetic core may be disposed in the region <NUM> as well. The magnetic core may be made of a magnetic material, such as ferrite. However, embodiments are not limited thereto. The material constituting the magnetic core may vary depending on the embodiment.

<FIG> is a cross-sectional view illustrating a coil accommodation structure disposed on a top surface of the coil frame according to an embodiment. <FIG> is a vertical cross-sectional view of the first coil accommodation structure 304a, the second coil accommodation structure 304b, and the magnetic flux generation region <NUM> on the coil frame <NUM> shown in <FIG>, which are cut in the Y1↔Y2 direction.

Referring to <FIG> and <FIG>, each of the first and second coil accommodation structures 304a and 304b disposed on a top surface of the coil frame <NUM> has one or more coil receiving grooves defined therein as described above. That is, as shown in <FIG>, in each of the first and second coil accommodation structures 304a and 304b, a coil receiving groove <NUM> is defined between two spacing walls 42a and 42b. The first coil accommodation structure 304a and the second coil accommodation structure 304b may each include a plurality of spacing walls, and coil receiving grooves defined between adjacent spacing walls.

A width of the coil receiving groove, that is, a spacing between adjacent spacing walls 42a and 42b, may be set to be greater than or equal to a width of the coil inserted into the first and second coil accommodation structures 304a and 304b. Further, a depth of the coil receiving groove, that is, a height of each of the spacing walls 42a and 42b, may be set to be greater than or equal to a height of the coil.

<FIG> is a side view of a coil holding structure placed above the top surface of the coil frame according to an embodiment. <FIG> shows structure of the second coil holding structure 308b of the two coil holding structures 308a and 308b. The first coil holding structure 308a may have a same construction as that shown in <FIG>.

Referring to <FIG> and <FIG>, the second coil holding structure 308b may be spaced by a predetermined height apart from a top surface of the coil frame <NUM>. As shown in <FIG>, the second coil holding structure 308b may be supported by two vertical supports 52a and 52b and may be spaced vertically from the coil frame <NUM>. Accordingly, a space <NUM> through which the working coil may pass may be defined between the second coil holding structure 308b and the coil frame <NUM>.

<FIG> shows that when a working coil is placed on the coil frame, the working coil turns around the coil holding structure, thereby changing a direction of extension of the working coil, according to an embodiment. That is, <FIG> shows an embodiment in which the extending direction of working coil <NUM> accommodated in the second coil accommodation structure 304b is switched by the second coil holding structure 308b. Although not shown, the extending direction of the working coil <NUM> accommodated in the first coil accommodation structure 304a may be switched by the first coil holding structure 308a.

Referring to <FIG>, the working coil <NUM> extending in the first direction (from X1 to X2) in the second coil accommodation structure 304b may pass through the second intersecting space 310b and pass under the second coil holding structure 308b. Then, the working coil <NUM> may turn upwardly around the second coil holding structure 308b and again extends in the second coil accommodation structure 304b in the second direction (from X2 to X1).

Referring further to <FIG>, the working coil <NUM> extending in the second direction (to X1 from X2) in the second coil accommodation structure 304b may pass through the second intersecting space 310b and pass above the second coil holding structure 308b. Then, the working coil <NUM> may turn downwardly around the second coil holding structure 308b and again extend in the second coil accommodation structure 304b in the first direction (to X2 from X1).

When the working coils extend in and along the first coil accommodation structure 304a and the second coil accommodation structure 304b, the first coil holding structure 308a and the second coil holding structure 308b may change the direction of the working coil from the first direction (X1 ---> X2) to the second direction (X2 → X1) or change the second direction (X2 → X1) to the first direction (X1 → X2). Depending on the embodiment, the working coil may extend below the first coil holding structure 308a or the second coil holding structure 308b to turn upward around the first coil holding structure 308a or the second coil holding structure 308b. Otherwise, the working coil may extend above the first coil holding structure 308a or the second coil holding structure 308b to turn downward around the first coil holding structure 308a or the second coil holding structure 308b.

<FIG> shows an example of a working coil placed on a coil frame according to an embodiment. One or more coil-receiving grooves defined in the first and second coil accommodation structures 304a and 304b illustrated in <FIG> and <FIG> above may accommodate the working coil having a predetermined length and thickness. In this regard, as shown in <FIG>, a cross section of the working coil <NUM> inserted in the coil-receiving groove may have a rectangular shape. Using such a working coil <NUM> having a rectangular cross section, a top surface of the working coil <NUM> becomes flat when the working coil <NUM> extends within the first and second coil accommodation structures 304a and 304b. Thus, when a current is applied to the working coil <NUM> and an inductive magnetic field is generated between the coil and the cooking vessel, an effect of increasing the magnetic flux density may be expected.

However, the cross section of the working coil inserted into the groove of the coil frame according to embodiments is not limited to the rectangular shape. A working coil having a different cross section, such as a circular shape, may also be used.

<FIG> shows that the working coil extends in a first direction on the coil frame according to an embodiment. <FIG> shows that an extension direction of the working coil on the coil frame is switched from a first direction to a second direction according to an embodiment.

Referring first to <FIG>, in one embodiment, the working coil <NUM> may be inserted into a first coil receiving groove in the first coil accommodation structure 304a on the coil frame <NUM> in the first direction (X1 → X2). With this connection, the working coil <NUM> may pass under the first coil holding structure 308a and be inserted into the first coil receiving groove formed in the first coil accommodation structure 304a. Alternatively, the working coil <NUM> may extend above the first coil holding structure 308a and be inserted into the first coil receiving groove.

The working coil <NUM> inserted in the first coil receiving groove may pass under the second coil holding structure 308b. Alternatively, the working coil <NUM> inserted in the first coil receiving groove may pass above the second coil holding structure 308b.

Next, referring to <FIG>, the working coil <NUM> passing under the second coil holding structure 308b in <FIG> may turn upwardly around the second coil holding structure 308b. Accordingly, the extending direction of the working coil <NUM> may be switched from the first direction (from X1 to X2) to the second direction (from X2 to X1). The working coil <NUM> having the extended direction switched to the second direction (from X2 to X1) may be then inserted into a second coil receiving groove in the first coil accommodation structure 304a and then passed under the first coil holding structure 308a.

Thereafter, the working coil <NUM> passing under the first coil holding structure 308a may turn upwardly around the first coil holding structure 308a. Accordingly, the extending direction of the working coil <NUM> may be switched from the second direction (from X2 to X1) to the first direction (from X1 to X2).

As the alternating switching of the extension direction is repeated, the working coil <NUM> extends alternately between the first direction (from X1 to X2) and the second direction (from X2 to X1). Thus, the working coil may be inserted into and extend in all of the coil receiving grooves formed in the first coil accommodation structure 304a.

Likewise, in one embodiment, the working coil <NUM> may be inserted into a first coil receiving groove in the second coil accommodation structure 304b on the coil frame <NUM> in the first direction (X1 → X2). With this connection, the working coil <NUM> may pass under the first coil holding structure 308a and be inserted into the first coil receiving groove formed in the second coil accommodation structure 304b. Alternatively, the working coil <NUM> may extend above the first coil holding structure 308a and be inserted into the first coil receiving groove.

Next, referring to <FIG>, the working coil <NUM> passing under the second coil holding structure 308b in <FIG> may turn upwardly around the second coil holding structure 308b. Accordingly, the extending direction of the working coil <NUM> may be switched from the first direction (from X1 to X2) to the second direction (from X2 to X1). The working coil <NUM> having the extended direction switched to the second direction (from X2 to X1) may be then inserted into a second coil receiving groove in the second coil accommodation structure 304b and then passed under the first coil holding structure 308a.

As the alternating switching of the extension direction is repeated, the working coil <NUM> may extend alternately between the first direction (from X1 to X2) and the second direction (from X2 to X1). Thus, the working coil may be inserted into and extend in all of the coil receiving grooves formed in the second coil accommodation structure 304b.

<FIG> shows that a first coil accommodation structure and a second coil accommodation structure on the coil frame accommodating different first and second working coils respectively according to an embodiment. Referring to <FIG>, according to the extension method illustrated in <FIG> and <FIG> above, first working coil <NUM> may be inserted into grooves in first coil accommodation structure 304a. At the same time, according to the extension method illustrated in <FIG> and <FIG> above, second working coil <NUM> may be inserted into grooves in second coil accommodation structure 304b. Both ends of the first working coil <NUM> may be connected respectively to connectors 60a and 60b that electrically connect the first working coil <NUM> to a control unit or controller (not shown) or a power supply (not shown). Likewise, both ends of the second working coil <NUM> may be connected respectively to connectors 62a and 62b that electrically connect the second working coil <NUM> to a control unit or controller (not shown) or a power supply (not shown).

When the first and second working coils <NUM> and <NUM> are disposed in the first coil accommodation structure 304a and the second coil accommodation structure 304b, respectively, a heating operation of a cooking vessel may be performed by controlling an amplitude, magnitude, and timing of current applied to each of the first and second working coils <NUM> and <NUM> via the control of the control unit (not shown).

<FIG> shows that a first coil accommodation structure and a second coil accommodation structure on the coil frame accommodate a single working coil according to an embodiment. Referring to <FIG>, according to the extension method illustrated in <FIG> and <FIG> above, the single working coil <NUM> may be inserted into grooves in the first coil accommodation structure 304a. Subsequently, according to the extension method illustrated in <FIG> and <FIG> above, the single working coil <NUM> may be inserted into grooves in the second coil accommodation structure 304b. As shown in <FIG>, the working coil <NUM> extending in the first coil accommodation structure 304a may extend along a lower end of first coil holding structure 308a toward the second accommodation structure 304b. Alternatively, the working coil <NUM> extending in the first coil accommodation structure 304a may extend along a lower end of second coil holding structure 308b to the second coil accommodation structure 304b. Both ends of the working coil <NUM> may be connected respectively to connectors 60a and 60b that electrically connect the working coil <NUM> to a control unit or controller (not shown) or a power supply (not shown).

<FIG> is a perspective view of an induction heating device including a coil assembly according to an embodiment. Referring to <FIG>, an induction heating device <NUM> employing a free zone scheme may include a casing <NUM> that accommodates coil assembly <NUM> according to embodiments, and a cover plate <NUM> that seals the casing <NUM>. Further, a rectangular heating region <NUM> may be defined in a plate <NUM> contained within the cover plate <NUM>. This allows a user to freely place a cooking vessel, such as a pot or container to be heated, on or at any location in rectangular heating region <NUM>. In the embodiment shown in <FIG>, only one coil assembly <NUM> is disposed inside the casing <NUM>. In accordance with an embodiment, one or more coil assemblies may be disposed within the casing <NUM>.

As illustrated in <FIG>, the coil frame of the coil assembly <NUM> according to embodiments may have a rectangular shape. Further, an overall arrangement shape of the working coil alternately extending in between the first direction (X1 ---> X2) and the second direction (X2 → X1) in the coil accommodation structure on the coil frame may have a roughly rectangular shape.

When the coil assembly <NUM> according to embodiments is applied to the induction heating device having a rectangular heating region <NUM> as shown in <FIG>, the non-coil regions 220a to <NUM> corresponding to the heating region <NUM> but not corresponding to the working coils are absent between the working coils 212a, 212b, and 212c included in the conventional induction heating device <NUM> employing the free zone scheme, and between the working coils 212a, 212b, and 212c and the walls of the casing <NUM> as shown in <FIG>.

Thus, the induction heating device <NUM> employing the free zone scheme, including the coil assembly <NUM> according to embodiments may provide a constant heating power regardless of where the user places the cooking vessel on the heating region <NUM>. This may prevent reduction of power efficiency based on a position of the cooking vessel, and thus, prevent a heating time and cooking time from increasing, which may otherwise occur in the conventional induction heating device <NUM> as shown in <FIG>.

Embodiments disclosed herein provide a coil assembly and an induction heating device including a coil assembly, in which non-coil regions corresponding to a heating region but not corresponding to the working coils may be absent between the working coils included in the induction heating device employing the free zone scheme, and between the working coils and the walls of the casing, thereby to prevent reduction of power efficiency based on a position of a cooking vessel, and thus, to prevent a heating time and cooking time from increasing.

Embodiments disclosed herein provide an induction heating device with a new structure to overcome disadvantages of conventional induction heating devices with a free zone scheme. A coil assembly included in an induction heating device according to an embodiment may include a coil frame having a shape corresponding to a shape of a heating region defined in a plate. Further, the working coil included in the coil assembly according to an embodiment may extend alternately between opposite first and second directions, rather than extending circularly as in the conventional working coil. An overall arrangement shape of the working coil having such an alternating arrangement may have a rectangular shape instead of a circular shape or an elliptic shape as in the related art.

Thus, the induction heating device employing the free zone scheme, including the coil assembly according to embodiments, provides a constant heating power regardless of where a user places a cooking vessel on the heating-region. This may prevent reduction of power efficiency based on the position of the cooking vessel, and thus, to prevent a heating time and cooking time from increasing, which may otherwise occur in the related art induction heating device.

Embodiments disclosed herein provide a coil assembly that may include a coil frame; a coil accommodation structure disposed on a first surface of the frame; and a working coil extending in the coil accommodation structure. A direction of extension of the working coil may be alternated between opposite first and second directions. The coil accommodation structure may include first and second coil accommodation structures. The working coil may include first and second working coils. The first working coil may extend in the first coil accommodation structure, while the second working coil in the second coil accommodation structure. A magnetic flux generation region may be defined between the first coil accommodation structure and the second coil accommodation structure.

The coil accommodation structure may have a coil receiving groove defined therein for receiving the working coil therein. The coil assembly may further include first and second coil holding structures. The first and second coil holding structures may extend respectively along both opposing lateral elongate sides of the coil accommodation structure. The working coil may turn around the first coil holding structure such that the extension direction of the working coil changes from the first direction to the second direction. The working coil may turn around the second coil holding structure such that the extension direction of the working coil changes from the second direction to the first direction. A first intersecting space may be defined between the coil accommodation structure and the first coil holding structure, while a second intersecting space may be defined between the coil accommodation structure and the second coil holding structure.

The working coil may have a rectangular-shaped cross-section. The coil assembly may further include at least one magnetic core disposed on a second surface of the coil frame. The first surface may be opposite to the second surface.

Embodiments disclosed herein further provide an induction heating device that may include a cover plate including a plate, a heating region being defined in the plate; a coil assembly disposed below the plate, the coil assembly vertically overlapping the heating region; and a casing that houses the coil assembly. The casing may be blocked at a top thereof by the cover plate. The coil assembly may include a coil frame; a coil accommodation structure disposed on a first surface of the frame; and a working coil extending in the coil accommodation structure. A direction of the extension of the working coil may be alternated between opposite first and second directions.

The coil accommodation structure may include first and second coil accommodation structures. The working coil may include first and second working coils. The first working coil may extend in the first coil accommodation structure, while the second working coil in the second coil accommodation structure. A magnetic flux generation region may be defined between the first coil accommodation structure and the second coil accommodation structure. The coil accommodation structure may have a coil receiving groove defined therein for receiving the working coil therein.

The coil assembly may further include first and second coil holding structures. The first and second coil holding structures may extend respectively along both opposing lateral elongate sides of the coil accommodation structure. The working coil may turn around the first coil holding structure such that the extension direction of the working coil changes from the first direction to the second direction. The working coil may turn around the second coil-holding structure such that the extension direction of the working coil changes from the second direction to the first direction.

A first intersecting space may be defined between the coil accommodation structure and the first coil holding structure, while a second intersecting space may be defined between the coil accommodation structure and the second coil holding structure. The working coil may have a rectangular-shaped cross-section.

The coil assembly may further include at least one magnetic core disposed on a second surface of the coil frame. The first surface may be opposite to the second surface.

The non-coil regions corresponding to the heating region but not corresponding to the working coils may be absent between the working coils included in the induction heating device employing the free zone scheme, and between the working coils and the walls of the casing, thereby to prevent reduction of power efficiency based on the position of the cooking vessel, and thus, to prevent a heating time and the cooking time from increasing.

In the above description, numerous specific details are set forth in order to provide a thorough understanding of embodiments. The embodiments may be practiced without some or all of these specific details. Examples of various embodiments have been illustrated and described above. It will be understood that the description herein is not intended to limit the claims to the specific embodiments described. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the scope as defined by the appended claims.

Thus, a first element, component, region, layer or section could be termed a second element, component, region, layer or section without departing from the teachings of the pre-sent invention.

For example, if the device in the figures is turned over, elements described as "lower" relative to other elements or features would then be oriented "upper" relative the other elements or features.

Embodiments of the disclosure are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the disclosure. Thus, embodiments of the disclosure should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing.

Any reference in this specification to "one embodiment," "an embodiment," "example embodiment," etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.

Claim 1:
An inductive coil assembly for a cooking device, comprising:
a coil frame (<NUM>) having at least one coil accommodation structure (304a, 304b) disposed on a top face of the coil frame (<NUM>); and
a working coil (<NUM>) extending in the coil accommodation structure (304a, 304b), wherein a direction of the extension of the working coil (<NUM>) is alternated between a first and a second direction being opposite to each other,
wherein the coil frame (<NUM>) is coupled to at least one:
a first coil-holding structure (308a), wherein the working coil (<NUM>) turns around the first coil-holding structure (308a) such that the extension direction of the working coil (<NUM>) is changed from the first direction (X1X2) to the second direction (X2X1); and
a second coil-holding structure (308b), wherein the working coil (<NUM>) turns around the second coil-holding structure (308b) such that the extension direction of the working coil (<NUM>) is changed from the second direction (X2X1) to the first direction (X1X2).