Patent Description:
The illumination of a heating zone on a cooking hob is usually performed by light source elements arranged beside or between the heating elements. For example, the light source element is arranged in the centre of an induction coil, so that the centre of the heating zone is illuminated. However, an illumination of the heating zone itself is not possible.

<CIT> discloses an illumination device for a cooking zone element. Said cooking zone element is provided for a cooking hob covered by a transparent panel. The cooking zone element comprises a central cut-out arranged in a central portion of the cooking zone element. The illumination device is arranged in the central cut-out of the cooking zone element. A light source element is arranged beneath the central cut-out. An optical lens encloses the upper portion of said light source element. A conical light guide formed as conical tube is arranged inside the central cut-out and above the optical lens. However, this illumination device illuminates only the central portion of the cooking zone element.

It is an object of the present invention to provide a heating zone for a cooking hob, which allows an improved illumination of said heating zone.

The object of the present invention is achieved by the heating zone according to claim <NUM>.

According to the present invention there is provided a heating zone for a cooking hob, in particular for an induction cooking hob. The heating zone comprises an illumination device. The illumination device comprises:.

The insulating layer includes at least one light channel formed as a cut-out. The reflecting, diffusing and/or refracting layer covers at least the light channel. The light source element and the reflecting element are arranged such that a light beam from said light source element is redirected by the reflecting element into the light channel. The illumination device comprises at least one further reflecting, diffusing and/or refracting layer arranged beneath the insulating layer. Furthermore, the light source element and the reflecting elements are arranged in the centre of the heating zone, while a plurality of light channels extend radially.

The core of the present invention is the combination of the light source element, the reflecting element and the light channel formed as a cut-out in the insulating layer. The side walls of the light channel are formed by the insulating layer, while the top side of the light channel is formed by the reflecting, diffusing and/or refracting layer. This structure allows an improved illumination of the heating zone. There is also provided a further reflecting, diffusing and/or refracting layer. Moreover, the light source element and the reflecting elements are arranged in the centre of the heating zone, while a plurality of light channels extend radially.

Preferably, the light channel is elongated. This allows a large illuminated area.

In particular, the reflecting, diffusing and/or refracting layer is made of mica. The mica layer allows an even distribution of the light intensity.

Further, the insulating layer may be made of glass fibre.

Preferably, the thickness of the insulating layer is at least <NUM>, more preferably at least <NUM>, most preferably at least <NUM>. A higher thickness of said insulation layer advantageously increases stability and dampening to the light channels.

Preferably, the thickness of the insulating layer is at maximum <NUM>, more preferably at maximum <NUM>, most preferably at maximum <NUM>. A lower thickness of said insulation layer is advantageous in reduced space requirements. Thus, said lower thickness of the insulation layer reduces the entire build-in height of the heating elements and/or the cooking hob.

The present inventors have found that the thickness of the insulating layer is preferably within the range from at least <NUM> and at most <NUM>, more preferably from at least <NUM> to at most <NUM>, from at least <NUM> to at most <NUM>, from at least <NUM> to at most <NUM>, from at least <NUM> to at most <NUM>, from at least <NUM> to at most <NUM>, still more preferably in the range from at least <NUM> to at most <NUM>, in the range from at least <NUM> to at most <NUM>, and in the range from at least <NUM> to at most <NUM>.

Preferably, the further reflecting, diffusing and/or refracting layer is made of mica.

Preferably, the reflecting, diffusing and/or refracting layer and/or the further reflecting, diffusing and/or refracting layer are coloured or painted white.

Furthermore, the reflecting, diffusing and/or refracting layer and/or the further reflecting, diffusing and/or refracting layer may have a thickness less than <NUM>, preferably between <NUM> and <NUM>.

In particular, at least one reflecting element is a beam splitter, wherein said beam splitter includes a plurality of mirror elements, and wherein preferably the beam splitter is made of plastics, glass, borosilicate or metal, e.g. aluminium or steel.

According to a preferred embodiment of the present invention the reflecting elements are arranged opposite to the light channels.

Further, at least one reflecting element may be a prism, wherein preferably said prism includes a concave surface section.

Further, at least one support element may have a reflective supporting geometry.

Additionally, the illumination device may comprise at least one support device for supporting the at least one light source element and the at least one reflecting element.

Moreover, the illumination device may comprise at least one light mask arranged above the reflecting, diffusing and/or refracting layer.

The illumination device may comprise a plurality of light source elements, wherein preferably said light source elements are separated by light screen elements.

At last, the present invention relates to a cooking hob, in particular an induction cooking hob, wherein said cooking hob comprises at least one heating zone cited above.

The present invention will be described in further detail with reference to the drawings, in which.

<FIG> illustrates a schematic perspective view of a heating zone <NUM> with an illumination device <NUM> according to a first embodiment of the present invention. In this example, the heating zone is an induction coil of an induction cooking hob. However, the illumination device <NUM> according to the present invention may be applied to other heating zones.

The illumination device <NUM> comprises a support device <NUM>. Said support device <NUM> is arranged in the centre of the heating zone <NUM>. One light source element <NUM> and three reflecting elements <NUM> are attached at said support device <NUM>. The heating zone <NUM> is covered by an insulating layer <NUM>. In this example, the insulating layer <NUM> is a circular disk. Three light channels <NUM> are formed as cut-outs in said insulating layer <NUM>. In general, an arbitrary number of light channels <NUM> may be formed as cut-outs in the insulating layer <NUM>. The light channels <NUM> extend into radial directions. A further cut-out is formed in the centre of the insulating layer <NUM> and above the support device <NUM> for the light source element <NUM> and the reflecting elements <NUM>. Preferably, the insulating layer <NUM> is made of glass fibres. In this example, the insulating layer <NUM> has a thickness of <NUM>. In general, the thickness of the insulating layer is within the range between <NUM> and <NUM>.

In this example, the light source element <NUM> and the reflecting elements <NUM> are arranged in the centre of the heating zone <NUM> or induction coil, respectively. In general, the light source element <NUM> and the reflecting elements <NUM> are arranged in a relative cold area of the heating zone <NUM>, e.g. beside or close to said heating zone <NUM>. Moreover, the light source element <NUM> and the reflecting elements <NUM> may be arranged in an area, which is cooled down, e.g. in a cooling channel.

An upper reflecting, diffusing and/or refracting layer is arranged above the insulating layer <NUM>. Said reflecting, diffusing and/or refracting layer covers the heating zone <NUM>. The top side of the light channels <NUM> are closed by the reflecting, diffusing and/or refracting layer. The upper reflecting, diffusing and/or refracting layer may be formed as a circular disk.

Preferably, the upper reflecting, diffusing and/or refracting layer is made of mica. In particular, said mica layer is white coloured or painted. The layer made of mica is suitable for reflecting, diffusing and refracting light as well. The thickness of the reflecting, diffusing and/or refracting layer is less than <NUM>, preferably between <NUM> and <NUM>.

Further, a lower reflecting, diffusing and/or refracting layer <NUM> is arranged beneath the insulating layer <NUM>. Preferably, the lower reflecting, diffusing and/or refracting layer <NUM> is also made of mica. In particular, said mica layer is also white coloured or painted. For example, said lower reflecting, diffusing and/or refracting layer <NUM> is directly glued on the induction coil. Preferably, the lower reflecting, diffusing and/or refracting layer <NUM> may be formed as a circular disk.

<FIG> illustrates a schematic detailed perspective view of the illumination device <NUM> on the heating zone <NUM> according to the first embodiment of the present invention.

The support device <NUM> is arranged in the centre of the heating zone <NUM>. The support device <NUM> includes a cylindrical circumferential wall. In this example, the bottom side and the top side of the support device <NUM> are substantially open. The light source element <NUM> is arranged in the centre of the heating zone and beneath the support device <NUM>. Preferably, the light source element <NUM> is a light emitting diode (LED).

The reflecting elements <NUM> are arranged inside the cylindrical circumferential wall of the support device <NUM> and attached at a ring. In turn, said ring is attachable or attached at the support device <NUM>. The three reflecting elements <NUM> are spaced equally from each other. The reflecting surfaces of the reflecting elements are directed inwardly. Each reflecting element <NUM> is arranged opposite to a corresponding light channel <NUM>. For example, the reflecting elements <NUM> are made of glass, borosilicate, plastics or metal. Further, the reflecting elements <NUM> may be coated by a metal layer.

A light beam from the light source element <NUM> is reflected by the reflecting elements <NUM> and redirected into the opposite light channels <NUM>. The reflecting, diffusing and/or refracting layer above said light channels <NUM> reflects and refract said light beam, so that an area above the heating zone <NUM> is illuminated.

Further, the reflecting element <NUM> may be a beam splitter including several reflecting surfaces, i.e. mirrors. For example, the beam splitter includes three mirrors. The beam splitter may be directly arranged above the light source element <NUM>. The beam splitter may be made of glass, borosilicate, plastic or metal, e.g. aluminium or steel. For example, the beam splitter made of plastic or metal has a circular shape with a hole in its centre, wherein the light is reflected by the plastic or metal. The beam splitter may be coated by a reflective material, e.g. chrome. The beam splitter allows internal total reflections. The beam splitter may be positioned in an area, where no influence of the electromagnetic field of the induction coil occurs.

<FIG> illustrates a schematic perspective view of the heating zone <NUM> with the illumination device <NUM> according to the first embodiment of the present invention. For clarity, the support device <NUM> with the three reflecting elements <NUM> is removed from its position in the centre of the heating zone <NUM>. The light source element <NUM> is arranged in the centre of the heating zone and beneath the support device <NUM>.

<FIG> illustrates a schematic perspective view of the support device <NUM> for the illumination device <NUM> according to the first embodiment of the present invention.

The support device <NUM> includes the cylindrical circumferential wall. In this example, the top side of the support device <NUM> is substantially open, while the bottom side of the support device <NUM> is partially or completely closed. The light source element <NUM> is arranged on the bottom of the support device <NUM>. In this example, the light source element <NUM> is a light emitting diode (LED). The reflecting elements <NUM> are attached at a ring. In turn, said ring is clamped within the support device <NUM>.

Further, three support elements <NUM> are arranged within the circumferential wall of the support device <NUM>. Each support element <NUM> corresponds with one reflecting element <NUM>. Said support elements <NUM> are arranged outside of the reflecting elements <NUM>. The reflecting elements <NUM> act as beam splitter and effectively as reflecting devices. The support elements <NUM> support the reflecting elements <NUM> in redirecting the light beam from the light source element <NUM> into the light channels <NUM>.

<FIG> illustrates a schematic perspective view of the support device <NUM> for the illumination device <NUM> according to the first embodiment of the present invention. In <FIG>, the ring with the three reflecting elements <NUM> is removed from the support device <NUM> for purpose of clarity. The support elements <NUM> are arranged within the circumferential wall of the support device <NUM> and equally spaced from each other.

<FIG> illustrates a schematic perspective view of the support device <NUM> for the illumination device <NUM> according to a second embodiment of the present invention.

The support device <NUM> includes the cylindrical circumferential wall. In this example, the top side of the support device <NUM> is substantially open, while the bottom side of the support device <NUM> is partially or completely closed. The light source element <NUM> is arranged on the bottom of the support device <NUM>. Preferably, the light source element <NUM> is a light emitting diode (LED).

Instead of the three reflecting elements <NUM>, three prism elements <NUM> are attached at a support plate <NUM> in the second embodiment. In turn, the support plate <NUM> is attached within the support device <NUM>. The prism elements <NUM> are attached at the bottom side of the support plate <NUM>.

<FIG> illustrates a schematic perspective view of the support device <NUM> for the illumination device <NUM> according to the second embodiment of the present invention. For clarity, the support plate <NUM> with the three prism elements <NUM> is removed from the support device <NUM>. Moreover, the upper and lower sides of the support plate <NUM> with the three prism elements <NUM> are shown in <FIG>. The prism elements <NUM> act as beam splitters and reflecting elements.

<FIG> illustrates a schematic perspective view of the support device <NUM> for the illumination device <NUM> according to a third embodiment of the present invention.

Three support elements <NUM> are arranged within the circumferential wall of the support device <NUM>. Each support element <NUM> includes a concave surface section <NUM>. The support elements <NUM> act as beam splitter and effectively as reflecting devices. The support elements <NUM> support the reflections in order to redirect the light beam from the light source element <NUM> into the light channels <NUM>.

Optionally, a light mask may be arranged above the upper reflecting, diffusing and/or refracting layer. Said light mask allows a specific light filtering.

The illumination device <NUM> according to the present invention allows an improved illumination of the heating zone <NUM>. Said illumination device <NUM> may be realised by simple manufacturing and low complexity. The inventive illumination device <NUM> does not increase the thickness of the heating zone <NUM>.

Claim 1:
A heating zone (<NUM>) for a cooking hob, in particular for an induction cooking hob, wherein:
- the heating zone (<NUM>) comprises an illumination device (<NUM>),
- the illumination device (<NUM>) comprises at least one light source element (<NUM>),
- the illumination device (<NUM>) comprises at least one reflecting element (<NUM>), and
- the illumination device (<NUM>) comprises at least one reflecting, diffusing and/or refracting layer,
characterised in that
- the illumination device (<NUM>) comprises at least one insulating layer (<NUM>) horizontally arranged within the heating zone (<NUM>),
- said insulating layer (<NUM>) includes at least one light channel (<NUM>) formed as a cut-out,
- the reflecting, diffusing and/or refracting layer covers at least the light channel (<NUM>),
- the light source element (<NUM>) and the reflecting element (<NUM>) are arranged that a light beam from said light source element (<NUM>) is redirected by the reflecting element (<NUM>) into the light channel (<NUM>);
wherein the light source element (<NUM>) and the reflecting elements (<NUM>) are arranged in the centre of the heating zone (<NUM>), while a plurality of light channels (<NUM>) extend radially;
wherein the illumination device (<NUM>) comprises at least one further reflecting, diffusing and/or refracting layer (<NUM>) arranged beneath the insulating layer (<NUM>).