PRIOR ART Lighting of rooms or surfaces is possible via externally mounted or integrated lighting elements at the level of an architectural object. The integrated illumination method has the advantage that the physical presence of the lighting does not affect the architectural character of the object with which the lighting is connected. In addition to this architectural or aesthetic aspect, integrated lighting often also contributes to safety. For example, in the case of a stairway, integrated lighting undoubtedly contributes to the safety of, for instance, but not exclusively, the elderly.

As lighting technology, LED lighting has several important advantages over 'traditional' technologies (incandescent and fluorescent lamps). Among others, LED lamps do not give off much heat and present a long life span (high number of burning hours).

DE 2020 070 14491, entitled "Treppenstufenbeleuchtung fur Treppenrenovierungen und -sanierungen", in the name of Rheingold GmbH, describes a renovation element for a stairway in which an LED lighting element is contained. The integrated lighting ensures that the stair tread and stair covering are illuminated perfectly in the middle. In this renovation element, a 'stair-like' recess is present. Herein, the centrally located recess is provided for an LED strip and the recess located at the edge and more at the surface, is provided for the semi-transparent PVC-cover. LED strip and semi-transparent PVC cover are hereby fixed to the respective recess by means of double-sided tape.

For Maintenance or replacement of said LED strip and/or semi-transparent PVC cover, the virtually permanent fixation of these elements causes a problem. A manually detachable configuration of a lighting element, without the use of adhesives, would be an added value in terms of future maintenance. Replacement of said semi-transparent PVC cover in a transparent covering material would increase the amount of light available for illumination of a stairway surface. Finally, the design of said LED strip and/or semi-transparent PVC cover is in practice with respect to measurements too large to be placed at specific parts of a stairs which exhibits narrow dimensions, for example, but not exclusively, tapered stair treads in a pivot point of a staircase.

There is a need for an easy to maintain integrated LED lighting element with good lighting quality and reduced dimensions, which among others is suitable for staircase lighting applications.

The present invention aims to find a solution to at least one of the above-mentioned problems. SUMMARY OF THE INVENTION

In a first aspect, the invention relates to a panel comprising an LED luminaire, which is provided in a recess of the panel, wherein the LED-luminaire comprises a housing which contains an LED module, and wherein the housing on the outside is provided with frictional fingers, for the frictionally incorporating in the recess of the panel.

Herein, the frictional incorporation of the LED luminaire offers an advantage both for installation and maintenance, since the incorporation is easily achieved by arranging the LED luminaire into the recess of the panel, while this incorporation can be undone by applying a mere pressing movement on the LED luminaire, as a result of which the frictional contact with the panel is broken.

Preferably, the housing of the LED luminaire consists of a transparent covering element by means of clamping elements detachably attached to a holding structure.

Herein, the detachable attachment mechanism has the advantage that in case of damage of the covering element, holding structure or in case of a defect to an LED module, these elements can be repaired or replaced individually without a complete replacement of the LED luminaire being required.

In a second aspect, the invention relates to a kit for staircase carpeting according to claim 11. In a third aspect, the invention relates to a method for covering a staircase by means of the kit according to claim 11. In a final aspect, the invention relates to a staircase, according to claim 13.

Further preferred embodiments have been elaborated in the sub-claims.

DESCRIPTION OF THE FIGURES For a better understanding of the present invention, reference is made to the detailed description of the invention, by way of example, which should be read in combination with the following figures, in which corresponding elements are given the same reference numbers:

Figure 1 is a representation of a possible embodiment of the LED luminaire according to the present invention, contained in the milling opening of a panel according to a possible embodiment of the present invention.

Figure 2 is a detail view of a possible embodiment of the LED luminaire according to the present invention.

Figure 3 shows in detail a possible embodiment of the transparent covering element and the holding structure according to the present invention.

Figure 4 is a detail view of another possible embodiment of the LED luminaire according to the present invention.

Figure 5 shows a side view of a carpeted stair tread according to a possible embodiment of the present invention, wherein the carpeting corresponds to an angular covering element, and a panel with integrated LED luminaire according to a possible embodiment of the present invention.

Figure 6 shows a perspective view of a staircase with carpeted stair treads according to a possible embodiment of the present invention.

Figure 7 is a side view of a staircase with carpeted stair treads according to a possible embodiment of the present invention, wherein the lighting of the staircase is shown according to a possible embodiment of the present invention. DETAILED DESCRIPTION

The invention relates to a panel with an LED luminaire integrated in an inventive manner, kit and method for the attachment thereof.

The terms "comprise", "comprising", "comprises", "consisting of", "provided with", "contain" are synonyms and are inclusive or open terms that indicate the presence of what follows, and which do not preclude or prevent the presence of other components, features, elements, members, steps, known from or disclosed in the prior art.

The citation of numerical intervals by endpoints comprises all integer numbers, fractions and/or real numbers between the endpoints, including these endpoints. Unless defined otherwise, all terms used in the description of the invention, including technical and scientific terms, have the meaning as they are commonly understood by the person skilled in the technical field of the invention.

In a first aspect, the invention relates to a panel comprising a LED luminaire, which is provided in a recess of the panel, wherein the LED luminaire comprises a housing which contains an LED module, and wherein the housing on the outside is provided with frictional fingers, for the frictional incorporation in the recess of the panel. With the term panel, reference is made to an object with limited thickness relative to its length and width. A panel according to the present invention is preferably used as part of an architectural object such as, for example, a staircase, a cupboard or ceiling. Obviously, it is not excluded that a panel according to the present invention as such is applied, or that a panel according to the present invention is used as a component in any object. By the term frictional fingers, reference is made to protrusions of limited dimensions with respect to the housing, positioned on the outside of the housing, which causes a frictional contact between the LED luminaire and panel. Herein, it is necessary that the dimensions of the recess, arranged in the panel, are adjusted to the dimensions of the LED luminaire. In a preferred embodiment, the LED luminaire is provided with four frictional fingers, wherein the 4 frictional fingers are incorporated symmetrically at 4 corner points of the housing. In a more preferred embodiment, the housing of the LED luminaire comprises 4 additional frictional fingers on the outside of the housing, in addition to 4 frictional fingers which are incorporated symmetrically at 4 corner points of the housing . Herein, an additional frictional finger is provided preferably at an equal distance with respect to any frictional finger incorporated at a corner point.

In one aspect of the panel, the panel is made of a type of wood or composite material. Non-limiting examples of possible types of wood are American maple wood, beech wood and European oak wood. The term composite refers to a material composed of different materials in order to thus obtain properties which cannot be obtained with the single materials. A non-limiting example of a composite material is laminate, which is composed of several layers which are compressed to form a board. Other non-limiting examples of composite materials are particle boards, MDF ("Medium-Density Fibreboard") and HDF ("High-Density Fibreboard"). The application of a covering layer is a way to change the panel's view. In the presence of linoleum objects in the vicinity of the panel, for example, it may be desirable to provide the panel with a covering layer in linoleum. Other non-limiting examples of materials suitable for a covering layer are carpet and vinyl. Besides the aesthetic appearance, a covering layer acts, when applied to a panel, also as a protective layer of the panel. A recess in a panel, whether or not provided with a covering layer, can be obtained by carrying out a sawing or milling movement. A jigsaw is an example of an applicable saw. In one aspect of the panel, the LED luminaire is frictionally detachably incorporated in the recess of the panel. Frictionally detachable indicates the reversible nature of the incorporation, without pronounced damage to the panel or LED luminaire when placing or removing the LED luminaire. The frictional detachable incorporation of the LED luminaire offers an advantage for both installation and maintenance, since the incorporation is easily achieved by arranging the LED luminaire into the recess of the panel, while this incorporation can be undone by applying a mere pressing movement to the LED luminaire, as a result of which the frictional contact with the panel is broken. In one aspect of the panel, the LED luminaire comprises an elongated mirror- symmetrical housing. The housing may be angular, oval-shaped or elliptical. In a preferred embodiment, the corners are rounded. The housing is made of a plastic material. Non-limiting examples of suitable plastics materials for the housing are PVC and polycarbonate. Preferably, the housing is made of polycarbonate. The housing is manufactured by means of injection molding. In one aspect of the panel, the housing of the LED luminaire is provided with recesses at the ends in the longitudinal direction for the passage of electric cables to close an electronic circuit. Preferably, these recesses are located on the underside of the housing of the LED luminaire, so that an LED module, contained in a LED luminaire, can be connected to an electronic circuit without electric cables being visible at the exterior of the LED luminaire or the panel.

In one aspect of the panel, the housing of the LED luminaire consists of a transparent covering element detachably attached to a holding structure by means of clamping elements. By the term clamping elements, reference is made to the protrusions of the transparent covering member, with limited dimensions in relation to the latter. These clamping elements can be arranged in recesses present in the holding structure, as a result of which an attachment by means of clamping is obtained. By the term detachable, reference is made to the reversible nature of the clamping, without pronounced damage to the holding structure or covering element when attaching or detaching. The covering element and the holding structure together form a sealed off space in which the LED module is contained. The detachable attachment mechanism has the advantage that in case of damage of covering element, holding structure or in case of a defect in an LED module, these elements can be repaired or replaced individually without a complete replacement of the LED luminaire being required. The transparent covering element is preferably polished, which contributes to a uniform distribution of light going out of the LED module.

In one aspect of the panel, the housing of the LED luminaire preferably has a width between 6 and 9 millimeters. The frictional fingers, comprised on the outside of the housing, preferably have a width between 0.15 and 0.65 mm, and more preferably a width between 0.25 and 0.55 mm.

In one aspect of the panel, the housing of the LED luminaire preferably has a height of between 3 and 5 millimeters.

In one aspect of the panel, the housing of the LED luminaire preferably has a length between 155 and 159 millimeters. The limited preferred dimensions of the housing of the LED luminaire for both width, height and length allow, in contrast to those known in the prior art, for incorporation in most configurations of stair treads. The LED luminaire according to embodiments of the present invention, for example, can be incorporated in stair treads of a spiral staircase, wherein a tread undergoes a narrowing. In addition, these limited preferred dimensions allow for the incorporation of the LED luminaire in parts of other objects with limited dimensions, such as, for example, in a part of a cupboard with limited dimensions or in a part of a ceiling with limited dimensions.

In one aspect of the panel, the housing of the LED luminaire has a width-to-height ratio of maximum 3.

In a second aspect, the invention relates to a kit for a stair tread covering comprising one or more panels with integrated LED luminaire according to one of the preceding embodiments and one or more angular covering element for a stair tread. The angle- shaped covering elements comprise at least one tread board and a head side attached thereto, positioned at an angle with respect to the tread board. The angle- shaped covering elements are, like the panels, made of a type of wood or a composite material. The angle-shaped covering elements may also be covered, like the panel, with a thin covering layer. For specific examples of materials applicable for the angle-shaped covering elements, reference is made to the above examples relating to possible materials for the panel. Application of the kit for stair tread covering on a staircase modifies the view of the present staircase. This aspect makes the kit of the present invention very suitable for renovation purposes. Additionally, the integrated LED modules, belonging to the panels of the renovation kit, provide an orientation lighting of the staircase, which increases the safety of the staircase. While, based on the above kit, it can be presumed that the LED modules, present in individual LED luminaires in active state are continuously powered via connection to the power supply, it should be emphasized that the present invention lends itself to various forms of energy supply. A possibility is a piezo-electric element at the level of the tread area of a staircase tread, in which the lighting of the respective tread is switched on when a pressure is exerted on this tread, for example by a footstep (JP2007 134226). In addition, the application of a motion sensor can ensure that the LED module, for a certain period of time, is automatically switched on at the moment when a movement is detected. In a particular set-up, upon detection by one motion sensor one or more LED modules can be activated. Another possible setup provides for a sequential lighting of a staircase, by means of individual motion detectors at the level of each stair tread. In addition, one could think of sensors which measure the ambient brightness (expressed in Lux), wherein on the basis thereof, the illuminance of the LEDs in the LED modules is adjusted. An alternative kit, at least comprising one or more panels with integrated LED luminaire according to embodiments of the present invention, optionally comprising additional elements, such as, for example, fastening elements such as screws, can be composed for a particular application. Non-limiting examples of such applications are a kit for providing a panel with integrated LED luminaire, according to the present invention, in a cupboard, such as, for example, a display or interior cupboard, or in a ceiling.

A third aspect of the present invention related to a method for covering a staircase by means of a kit for stair tread covering according to the present invention, wherein the method comprises:

- The placement of angle-shaped covering element over an existing stair tread;

The attachment of a panel with integrated LED luminaire against the underside of the nose of a stair tread;

The connection of the LED module with components of an electronic circuit.

The tread board of an angle-shaped covering element, when placed, will come to lie over the top side of the stair tread, while the head part of an angle-shaped covering element will be positioned at the front of the stair tread. A panel with integrated LED luminaire, according to one or more embodiments of the present invention, is placed against the underside of the nose of a stair tread. The nose is the part of a stair tread which protrudes over the stair covering, a vertical plane between the stair treads. The downward orientation of an LED luminaire contained in a panel, ensures that at least the underlying stair tread is illuminated. In addition, the integrated LED luminaire can also provide lighting of a stair covering. A final step of the method is the connection of the LED module, contained in the LED luminaire, with components of the electronic circuit. A plug and play connection method is a possibility to connect an LED module to an electronic circuit and offers the advantage that the LED module can be connected in a simple and fast manner. Alternative embodiments of the present invention relating to methods for providing a panel with integrated LED luminaire, according to the present invention, in any object or architectural object, can be reasoned by an average skilled person with knowledge of the technical field of the present invention . As essential steps, such methods comprise the attachment of a panel with integrated LED luminaire against an object, and the connection of the LED module with components of an electronic circuit. Such methods can be used, for example, to provide a cupboard, such as a display or interior cupboard, or a ceiling, with a panel with integrated LED luminaire. A final aspect of the invention relates to a staircase, wherein at least one stair tread is covered by means of the above-mentioned kit and/or according to the above- mentioned method. In what follows, the invention is described by means of non-limiting figures, which illustrate the invention, and which are not intended or should be interpreted to limit the scope of the invention.

Figure 1 shows a possible embodiment of the present invention, consisting of a wooden or composite panel (1) with a milled recess (2) in which an LED luminaire

(3) is frictionally incorporated in the recess (2) of the panel (1). As shown in the figure, a possible embodiment of the recess (2) corresponds to an elongated slit with rounded ends. Figure 2 shows the LED luminaire (3), according to a possible embodiment of the invention, in detail. In this embodiment of the present invention, the LED luminaire is an elongated structure with rounded ends (9). The LED luminaire (3) preferably consists of a housing, made up of a holding structure (4) and a transparent covering element (5), in which a LED module (6) is contained. The LED module (6) comprises at least one LED and at least one electrical connection. The transparent nature of the covering element (5) ensures that this element both shields the LED module (6) of the environment and lets outgoing light from LEDs to sufficiently pass through. Electric cables for connection of the LED module (6) onto the electronic circuit leave the LED luminaire (3) via cable passages (8). By means of clamping elements (11) of the transparent covering element (5), the latter is attached at the level of recesses (12) of the holding structure (4). At the top side of the holding structure

(4) , recesses (10) are provided where the covering element (5) can be approximated if it is desired for it to be removed. When transparent covering element (5) and holding structure (4) are attached to one another, clamping elements (11) of the transparent covering element (5) are clamped into recesses (12) on the underside of the holding structure (4). The latter clamping elements (11) and recesses (12) are clearly illustrated in Figure 3, in which transparent covering element (5) and holding structure (4) are shown separately, according to a possible embodiment of the present invention. As shown, a clamping element (11) consists of2 hook-shaped structures which are oriented outward in a V-shape. In side view of the holding structure (4), it can be observed that the shape of the laterally located recesses (12), seen from top to bottom, first is tapered and then widens. This structure of the laterally located recesses (12) ensures that, upon arranging the covering element (5), the clamping elements (11) are first pushed together and then past the tapered part, again go back to the original V-shape, with the clamping attachment between covering element (5) and holding structure (6) as a result. Rectangular protrusions (13) of the covering element (5), moreover, ensure that the covering element (5) in both the presence and absence of lateral forces is centrally aligned with respect to the holding structure (4). The design of laterally located recesses (12) allows that the clamping elements (11) can be released out of it when a tilting movement of the covering element (5) at the level of one of the or both recesses (10), located at the top side of the holding structure (4), is exerted. In the top view of the holding structure (4), the centrally located recess (14), provided for containing a LED module (6), can be observed. The detachable attachment mechanism by means of clamping elements (11) has the advantage that in case of damage of covering element (5), holding structure (4) or in case of a defect to the LED module (6), these elements can be repaired or replaced separately without a complete replacement of the LED luminaire (3) being required. The frictional incorporation of the LED luminaire (3) in the recess (2) of the panel (1) has its origin in the friction between the frictional fingers (7) and the edges of the recess (2). According to a possible embodiment of the invention, the frictional fingers (7) are wedge-shaped protrusions preferably located at the corners of the underside of the holding structure (4). Seen from top to bottom, the degree to which the frictional fingers protrude with respect to the holding structure (4) decreases. The design of the frictional fingers (7) allows the holding structure (4) or the entire LED luminaire (3), on the condition of a pressing movement, exerted on the top side, to be easily arranged into the recess (2) of the panel (1). Once integrated in the panel (1), the frictional fingers (7) will offer resistance to movement of the holding structure (4) or LED luminaire (3) with respect to the panel, by which it is held in place. A further pressure movement, also exerted on the top side, ensures that the holding structure (4) or LED luminaire (3) can be removed from the panel (1). This detachable incorporation of the LED luminaire (3) offers maintenance- technical advantages relative to integrated lighting luminaire which are undetachably (via, for example, tape or glue) attached to the object of which they form a part. Figure 4 is a detail view of another possible embodiment of the LED luminaire according to the present invention. This embodiment is similar to the possible embodiment of Figure 2, with the exception of a different number of frictional fingers (7), clamping elements (11) and recesses for incorporation of clamping elements (12). The embodiment shown in Figure 4 namely exhibits 2 times more frictional fingers (7), clamping elements (11) and recesses for incorporation of clamping elements (12), with respect to the possible embodiment shown in Figure 2. When the holding structure (4) or entire LED luminaire (3) according to the embodiment shown in Figure 4 is integrated into a milled recess (2) of a panel (1), the additional frictional fingers (7) offer an increased resistance to movement of the holding structure (4) or LED luminaire (3) relative to the panel. This increased resistance may be desirable when a panel (1) is exposed to substantial and/or frequently exerted external forces, such as, for example, a panel which is part of a frequently used staircase. A pressing movement exerted on the top of the holding structure (4) or LED luminaire (3), however, ensures that the holding structure (4) or LED luminaire (3) can be removed from the panel (1). Figure 5 shows an example of a panel with integrated LED luminaire as part of a kit for stair tread covering, according to a possible embodiment of the present invention. In the figure, a stair tread (16) is shown in side view, with further indication of a stair covering (17) and a nose (18). The nose (18) of a stair tread (16) is defined as the part of the stair tread (16) which protrudes over the stair covering (17). The depicted stair tread (16) is provided with an angle-shaped covering element (15) and a panel (1) with integrated LED luminaire (3), both belonging to the kit for stair tread covering. The angle-shaped covering element (15) comprises a horizontally shown tread board and a head side which are mutually connected to one another so as to form one covering element (15). When mounted on a stair tread (16), it can be observed that the bottom part of the head part in this possible embodiment protrudes beneath the stair tread (16). Inside the cavity delimited by the protruding head part, the nose (18) and the stair covering (17), a panel (1) with integrated LED luminaire (3) is attached against the underside of the nose (18), wherein the top side of the LED luminaire (3) (the side where the covering element (5) is located) is directed downwards. Figure 6 shows, according to a possible embodiment of the present invention, a perspective view of a number of stair treads (16) of a staircase in the above manner provided with angle-shaped covering element (15) and panel (1) with integrated LED luminaire (3). In Figure 7, finally, according to a possible embodiment of the present invention, in side view, the lighting of stair treads (16) of a staircase by means of integrated LED luminaire (3) is shown. The transparent covering element (5) ensures hereby that the light beams (19) created over the individual stair treads (16) exhibit an evenly light display. In addition, the central placement of the LED luminaire (3) in a panel (1), according to a possible embodiment of the present invention, ensures that the underlying stair covering (17) and the underlying stair tread (16) are exactly illuminated in the middle.

REFERENCE NUMBERS:

Panel (1)

Milled recess (2)

LED luminaire (3)

Holding structure (4)

Transparent covering element (5)

LED module (6)

Frictional fingers (7)

Recess for passage of electric cables (8)

Rounded ends (9)

Recess for removing covering element (10)

Clamping elements (11)

Recesses for incorporation of clamping elements (12)

Protrusions of transparent covering element (13)

Recess provided to include an LED module (14)

Angle-shaped covering element (15)

Stair tread (16)

Stair covering (17)

Nose of stair tread (18)

Light beam (19)