Hob comprising heating zone illumination means

Abstract

The invention relates to a hob comprising a transparent or semi-transparent hob plate (2) and multiple heating elements (3) arranged below said hob plate (2), the hob further comprising illumination means arranged below said hob plate (2) for providing light markings (4) at the upper side (2.1) of the hob plate (2), said light markings (4) indicating heating zones (5) associated with the heating elements (3), wherein the illumination means comprise a light box (10) with at least a bottom wall portion (11) and a pair of side wall portions (12), said light box (10) including one or more lighting elements (13) for illuminating an interior space (14) of the light box (10), wherein the light box (10) further comprises an upper portion (15) being adapted to emit light towards the hob plate (2) in order to provide said light marking (4) at the upper side of the hob plate (2).

Claims

1. A hob comprising: a transparent or semi-transparent hob plate; multiple heating elements arranged below said hob plate; illumination means arranged below said hob plate for providing light markings at an upper side of the hob plate, said light markings varying to indicate selected or activated heating zones associated with the heating elements, wherein the illumination means comprise a light box with at least a bottom wall portion and a pair of side wall portions, said light box including one or more lighting elements for illuminating an interior space of the light box, wherein the light box further comprises an upper portion being adapted to emit light towards the hob plate in order to provide said light marking at the upper side of the hob plate.

2. The hob according to claim 1, wherein the bottom wall portion and the side wall portions are integrally formed at the light box.

3. The hob according to claim 1, wherein at least one side wall portion of the light box comprises one or more apertures through which light is emitted into an interior space of the light box.

4. The hob according to claim 1, wherein the bottom wall portion is formed by a circuit board comprising said lighting elements.

5. The hob according to claim 1, wherein the wall portions of the light box comprise a light blocking material or a light-blocking finishing or coating at the outer side.

6. The hob according to claim 1, wherein the interior surface of the light box is adapted to diffuse and/or reflect light.

7. The hob according to claim 6, wherein at least the side wall portions of the light box are made of white, non-transparent material or comprise a light-dispersive and/or light-reflecting coating.

8. The hob according to claim 1, wherein the light box comprises at its top side a light diffusing portion which faces a bottom side of the hob plate.

9. The hob according to claim 8, wherein the light diffusing portion is made by a rigid diffusor plate or a diffusor foil.

10. The hob according to claim 1, comprising a lid which partially covers an opening of the light box in order to provide a narrowed light emitting aperture.

11. The hob according to claim 1, wherein the light box is made of heat resistant polybutylene terephthalate (PBT).

12. The hob according to claim 1, comprising multiple said light boxes being arranged at different positions below said hob plate, the lighting elements included in the respective light boxes being driven such that a heating zone formed by one or more of said heating elements is highlighted at the upper side of the hob plate.

13. The hob according to claim 12, wherein said multiple light boxes are adapted to highlight heating zones by completely bordering said heating zones by a solid illumination line or by partially bordering the heating zones by broken lines.

14. The hob according to claim 1, comprising a control unit being adapted to control illumination properties provided by the light box based on a cooking level, by changing at least one of light intensity, colour, line width and number of lines of the light markings.

15. The hob according to claim 1, comprising control means for selecting the size of a heating zone wherein the light marking provided by said light box is adapted based on the selected size of the heating zone, or comprising a pot detection mechanism for choosing an appropriate size of the heating zone wherein the light marking indicating the size of the heating zone is adapted based on information provided by the pot detection mechanism.

16. A hob comprising: a transparent or semi-transparent hob plate, a plurality of heating elements arranged below said hob plate and configured to provide a plurality of variable heating zones having different shapes and sizes based on either a user selection or a pot-detection system detecting an arrangement of cookware on an upper side of the hob plate, a plurality of light boxes also arranged below said hob plate in an array that encompasses said plurality of variable heating zones, and a controller; each said light box having non-transparent and light-reflective or -diffusive interior walls that define an interior space of the light box, an LED for generating light that permeates said interior space, said interior space being in light communication with a bottom side of said hob plate through an opening of said light box so that light from said interior space is visible from said upper side of said hob plate, a diffuser disposed adjacent said opening to diffuse light exiting said interior space toward said bottom side of said hob plate, said LED being positioned so that it is not in direct line-of-sight with said opening; said bottom side of said hob comprising a printed or coated layer that defines one or more light transmission slots in the hob layer to confine light emitted from the array of light boxes to defined apertures; said controller being operatively connected to and configured to selectively operate said array of light boxes in order to generate variable light markings visible from said upper side of said hob that indicate the size and shape of active heating zones; said upper side of said hob plate being devoid of fixed markings to indicate heating zones.

17. The hob according to claim 16, said controller further configured to regulate at least one of light intensity, color or thickness of said light markings based on an operative cooking level for an associated heating zone.

18. The hob according to claim 1, wherein at least one of the lighting elements is arranged outside the interior space of the light box and at least one side wall portion of the light box comprises one or more apertures through which light from the at least one of the lighting elements is emitted into an interior space of the light box.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The various aspects of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings, in which:

(2) FIG. 1 shows an example schematic perspective view of a hob;

(3) FIG. 2 shows an example schematic top view of a hob comprising multiple light markings indicating activated heating zones;

(4) FIG. 3 shows an example schematic top view of a hob comprising multiple light boxes arranged in a matrix-like configuration;

(5) FIG. 4 shows an example schematic cross-sectional side view of a hob including light boxes;

(6) FIG. 5 illustrates an example schematic side view of a light box included in a hob;

(7) FIG. 6 illustrates an example schematic cross-sectional side view of a light box according to a first embodiment;

(8) FIG. 7 shows an example schematic top view of a light box;

(9) FIG. 8 illustrates an example schematic cross-sectional side view of a light box according to a second embodiment;

(10) FIG. 9 illustrates an example schematic cross-sectional side view of a light box according to a third embodiment; and

(11) FIG. 10 illustrates an example schematic cross-sectional side view of a light box according to a fourth embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(12) The present invention will now be described more fully with reference to the accompanying drawings, in which example embodiments are shown. However, this invention should not be construed as limited to the embodiments set forth herein. Throughout the following description similar reference numerals have been used to denote similar elements, parts, items or features, when applicable.

(13) FIG. 1 shows a schematic illustration of a hob 1. The hob 1 may be, for example, an induction hob or a hob using resistance heating elements (resistance heating hob). The hob 1 comprises multiple heating zones 5 preferably provided at a common hob plate 2. Each heating zone 5 is correlated with at least one heating element 3 placed beneath the hop plate 2. Said heating elements 3 may be induction heating elements (e.g. an induction coil) or resistance heating elements. The induction hob 1 may further comprise a user interface 6 for receiving user input and/or providing information, specifically graphical information to the user. Preferably, the hob 1 may comprise heating zones 5 of variable size, i.e. the size of the heating elements can be adapted to the present needs, e.g. the size of a currently used piece of cookware. The size of the heating zone may be varied by aggregating multiple heating elements 3 in order to obtain a large-size heating zone 5 or switch off one or more heating elements 3 associated with a heating zone 5 in order to reduce its size.

(14) In order to provide flexible heating zone markings which can be adapted according to the present size/shape of a heating zone 5, the hob 1 is adapted to provide light markings 4 at the upper side 2.1 of the hob plate 2.

(15) FIG. 2 shows an example arrangement of multiple heating elements 3. Said heating elements 3 may be arranged in a matrix-like manner, i.e. the hob 1 may comprise heating elements 3 arranged in rows and columns. The bold lines indicate light markings 4 surrounding heating zones 5. The heating elements 3 associated with a certain heating zone 5 may be driven with the same electrical properties (e.g. electrical heating power) in order to form a heating zone 5 with an equal heating power distribution. The formation of the respective heating zones 5 may be manually chosen by the user based on the size and shape of the currently used piece of cookware. Alternatively, the formation of the heating zones 5 may be influenced by a pot detection mechanism. By means of said pot detection mechanism, the size/shape of the currently used piece of cookware may be detected automatically wherein the information provided by the pot detection mechanism is used for aggregating multiple heating elements 3 covered by a certain piece of cookware to a common heating zone 5.

(16) FIGS. 3 and 4 show technical means for providing upper-mentioned light markings 4 at the upper side 2.1 of the hob plate 2 in greater detail. The hob 1 comprises multiple light boxes 10 being arranged in the interior of the hob 1, i.e. at or close to the bottom side of the hob plate 2. The hob plate 2 may be of transparent or semi-transparent material, e.g. may be a glass-ceramic hob plate 2. The light boxes 10 may be arranged with respect to the heating elements 3 such that due to activating/deactivating of lighting elements 13 included in the light boxes 10, said light markings 4 may be provided at the upper side of the hob plate 2. For example, the light boxes 10 may be distributed over the hob plate 2. According to the present embodiment, the light boxes 10 may be arranged in rows and columns, specifically, in spaces between the heating elements 3 and at the outer edge of the heating area. The light boxes 10 may have a longitudinal shape and may extend through the whole or essentially the whole length and/or width of the hob plate 2. According to another embodiment, the light boxes may be segmented, i.e. may only partially surround a heating element 3 or a heating zone 5. The light boxes may have a linear shape (as shown in FIG. 3) or may have a curved shape (e.g. a bracket-like shape). When activating the lighting elements 13 within the light box 10, a stripe-like light may be emitted by the light box 10 and provided through the hob plate 2 thereby generating an illumination stripe at the upper surface of the hob plate 2. In addition, a masking may be provided at the bottom side 2.2 of the hob plate 2 in order to confine the illumination stripe. Said masking may be provided by a printing or coating at the bottom side 2.2 of the hob plate 2.

(17) As shown in FIG. 4, the light boxes 10 are arranged below the hob plate 2. The light boxes 10 may be integrated within the hob in different ways. For example, the light boxes 10 may be directly arranged at the bottom side 2.3 of the hob plate 2, may be directly provided at the carrier plate 7 of the heating elements 3, may be arranged at said heating elements 3 or may be coupled with a bracket to said carrier plate 7.

(18) FIGS. 5 to 7 show an example embodiment of a light box 10 in closer detail. The light box 10 comprises an elongated shape, i.e. the longitudinal side is significantly longer than the narrow side. The light box 10 is formed by a profile made of a heat-resistant material, preferably by a plastic profile. The plastic may be, for example, polybutylene terephthalate (PBT).

(19) The light box 10 is formed by a bottom wall portion 11 and two side wall portions 12 protruding from said bottom wall portion 11. The side wall portions 11 may be integrally formed at said bottom wall portion 11. Alternatively, the bottom wall portion 11 may be formed by a printed circuit board. Said side wall portions 12 and said bottom wall portion 11 may confine an interior space 14. At said bottom wall portion 11 in the interior space 14, one or more lighting elements 13 may be provided. Preferably, multiple lighting elements are distributed along the longitudinal side of the light box 10. Said lighting elements 13 may be, for example, light emitting diodes (LEDs) or electric light bulbs. According to the present embodiment, the light box is directly attached to the carrier plate 7 carrying the heating elements 3.

(20) The wall portions of the light box 10 may be adapted to provide reflecting and dispersing of light emitted by the lighting elements 13. For example, at least the side wall portions may be made of white material (e.g. plastic) and/or may comprise a light-reflective or light-dispersive coating. Thereby, the light emitted by the lighting elements is distributed within the interior space in order to obtain a uniform light distribution, i.e. light markings 4 at the upper surface of the hob plate 2 with a uniform light intensity. For example, the inner coating may be white or may be shadowed from black to white. In addition, the side wall portions 12 and the bottom wall portion 11 could be made of non-transparent material or comprise a non-transparent coating in order to avoid a transmission of light through said walls which may lead to a lighting of the hob plate 2 in undesired areas. For example, the outer coating of the wall portions may have a black or white colour or may be shadowed from black to white.

(21) The light box may comprise an upper portion 15 which faces the hob plate 2 and which is adapted to emit light to the bottom side 2.2 of the hob plate 2. Due to the at least semi-transparent hob plate 2, the light provided to the bottom side 2.2 passes through said hob plate 2 and forms a light marking 4 which can be visually perceived by a user of the hob.

(22) In order to homogenize the light, a light diffusor 17 may be provided at the upper portion 15 of the light box 10. Said light diffusor 17 may be, for example a diffusor plate or a diffusor foil. Said light diffusor 17 may be adapted to spatially homogenize the light provided by the light box 10 in order to achieve a spatially homogenous light marking 4. Alternatively or in addition, at the upper portion 15 a lid may be provided, said lid at least partially covering the opening through which light is emitted in order to confine the width of the light marking 4.

(23) FIGS. 8 to 10 show different cross-sectional views of light boxes 10. The embodiment of FIG. 1 comprises a concave-shaped interior space 14. Said concave-shaped interior space 14 is obtained by a concave-shaped bottom wall portion 11 and at least one concave-shaped side wall portion 12. The distance d between said side wall portions in the area of the interior space 14 may be smaller than the distance D at the upper edge 10.1 of the light box 10. In other words, the shaping of at least one of the side wall portions 12 is chosen such that the light passage is limited by an edge formed at the concave-shaped side wall portion 12. Thereby it is possible to place the lighting elements 13 in an area which does not have a direct line of sight to the light emitting aperture 18 provided at the upper portion 15.

(24) According to another embodiment, the bottom wall portion 11 and the side wall portion 12 may have a curved shape only in a corner area between the bottom wall portion 11 and the side wall portion 12 (FIG. 9). In other words, at least one corner area in the interior space 14 of the light box 10 is replaced by a rounded corner which further improves the homogeneity of light emission of the light box 10. Alternatively or in addition, at least one of the side wall portions 12 may have a tapered shape, specifically, the wall thickness increases from the upper edge 11.1 to the bottom wall portion 11 (FIG. 10).

(25) As shown in FIGS. 8 to 10, the lighting elements 13 may not be directly placed within the interior space 14 of the light box 10 but at least one side wall portion 12 may comprise an aperture 16 which passes through the said side wall portion 12 thereby providing a light passage through the said side wall portion 12.

(26) A lighting element 13 may be placed within said aperture 16 in order to provide light through said light passage into the interior space 14 of the light box 10 (as indicated by the arrow). The longitudinal axis of the aperture 16 providing said light passage may be arranged in parallel to the bottom wall portion 11 or may be provided in a slanted arrangement, i.e. the longitudinal axis of the light passage is slanted with respect to the longitudinal axis of the bottom wall portion 11. In a further embodiment, the lighting elements 13 may be placed at one or both lateral free ends of the elongated light box 10.

(27) By means of one or more of said light boxes 10, different markings of the heating zones 5 are possible. For example, the light box may be adapted to provide an illumination ring or illumination strip around the heating zone 5. Alternatively, multiple segmented illumination stripes may indicate the position and size of the heating zone 5 (bracket-like illumination stripes, illumination stripes in the corner region). In addition, one or more light dots may be provided in the middle of said heating zone 5 in order to indicate the center of the heating zone 5.

(28) Preferably, the light box 10 may be adapted to indicated the cooking level by optical indicators. For example, the light box may be adapted to change the intensity of color based on the chosen cooking level. According to other embodiments, the light box 10 may be adapted to change the color of the illumination stripes provided at the hob plate (e.g. yellow (low cooking level) to red (high cooking level)). Alternatively, the light box 10 may be adapted to change the thickness of the provided illumination stripe based on the chosen cooking level (thin line (low cooking level), thick line (high cooking level)). Still alternatively, the number of illumination stripes provided around the heating zone 5 may be adapted according to the chosen cooking level. It is worth mentioning that said upper-mentioned embodiments for illustrating the cooking level can be freely combined with each other.

(29) It should be noted that the description and drawings merely illustrate the principles of the proposed methods and systems. Those skilled in the art will be able to implement various arrangements that, although not explicitly described or shown herein, embody the principles of the invention.

LIST OF REFERENCE NUMERALS

(30) 1 hob

(31) 2 hob plate

(32) 2.1 upper side

(33) 2.2 bottom side

(34) 3 heating element

(35) 4 light marking

(36) 5 heating zone

(37) 6 user interface

(38) 7 carrier plate

(39) 10 light box

(40) 10.1 upper edge

(41) 11 bottom wall portion

(42) 12 side wall portion

(43) 13 lighting element

(44) 14 interior space

(45) 15 upper portion

(46) 16 aperture

(47) 17 light diffusing portion

(48) 18 light emitting aperture

(49) d distance

(50) D distance