DE29805006U1 - Furniture with lighting fixtures - Google Patents

Description

TER MEER STEINMEISTER & PARTNER GBR PATENT ATTORNEYS - EUROPEAN PATENT ATTORNEYS

Dr. Nicolaus ter Meer, Dipl.-Chem. Helmut Steinmeister, Dipl.-Ing.

Peter Urner, Dipl.-Phys. Manfred Wiebusch

Gebhard Merkle, Dipl.-Ing. (FH)

Mauerkircherstrasse 45 Artur-Ladebeck-Strasse 51

D-81679 MUNICH D-33617 BIELEFELD

HLM PO 1/98 . 18.3.1998

Eckhard Halemeier

Bakusbrink 35 32120 Hiddenhausen

FURNITURE WITH LIGHTING DEVICE

TERMEER STEINMEISTER & PARTNERS QBR··.,· ..··..· HLM PO 1/98

DESCRIPTION

The invention relates to a piece of furniture with a lighting device.

Furniture, especially cupboard furniture, often has lighting devices that are used, for example, to illuminate writing surfaces or bar compartments or that have a purely decorative function, for example as interior lighting for niches, display cabinets and the like. Conventional lighting devices that provide sufficient illuminance are relatively large and are therefore difficult to integrate into furniture parts such as the intermediate floor or the upper or side walls of the cupboard. Another problem is that, due to the relatively high heat generated by the lighting devices, special measures are required to ensure that there is no fire hazard with wooden furniture. This significantly limits the design options.

The object of the invention is therefore to equip furniture with a small-sized lighting device that offers versatile design options and is characterized by low heat generation.

This object is achieved according to the invention in that the lighting device is an array of light-emitting semiconductor elements.

Such light-emitting semiconductor elements, referred to below as LEDs, have so far only been used as control or signal lamps or as display elements due to their comparatively low light intensity. However, if a large number of such LEDs are combined in a linear or flat field, an illuminance can be achieved that is sufficient for lighting purposes in furniture. The advantage of using such LEDs is that they can be easily integrated into furniture parts due to their very small dimensions and extremely low heat generation. Furthermore, there is a cost saving due to the high efficiency and long service life of such LEDs.

In contrast to fluorescent lamps or incandescent lamps, LEDs normally only emit light in a very narrow spectral range. White light allows

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can be achieved by a combination of different colored LEDs whose light rays overlap. However, LEDs that emit white light are already known (US 5 684 309 A). With an output of 1 W, white light LEDs can currently have a luminous flux of 0.7 Lm or more, so that sufficient lighting can be achieved inside furniture parts or in their immediate vicinity.

Advantageous embodiments of the invention emerge from the subclaims.
10

In the following, embodiments of the invention are explained in more detail with reference to the drawing.

Show it:
15

Figure 1 shows a partial section of a furniture part with a

lighting device;

Figures 2 and 3 show partial sections through furniture parts with lighting devices according to other embodiments; and

Figure 4 is a schematic diagram of another embodiment of the

lighting device.

Figure 1 shows a partial section of a furniture part 10, which can be, for example, an upper wall or a shelf of a cupboard or a side wall of the cupboard. A lighting device 12 has a flat, pot-shaped or box-shaped housing 14 made of plastic, which, like the installation housing of a conventional halogen recessed light, is embedded in a recess in the furniture part 10. The housing 14 can have a round or optionally a rectangular cross-section.

A circuit board 16, which is equipped with a large number of LEDs 18 distributed over the surface, is locked into the housing 14 in such a way that it extends parallel to the opening and the LEDs 18 lie in the opening of the housing. The base 20 of the housing forms locking claws 22 with which the circuit board

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16. The circuit board is connected by supply lines (not shown) to an electronic circuit for supplying power to the LEDs, which is known per se and also not shown.

The LEDs 18 preferably emit white light and have, for example, each a power of 1 W and a luminous flux of 0.7 Lm or more.

Due to the special shape of the optical material of the LEDs, the light is essentially only emitted in a narrow solid angle range in the axial direction of the LEDs. This means that glare is largely avoided when installed in a side wall or floor of a cabinet. However, the radiation characteristics can optionally be changed by adding lenses, diffusers and the like.

The LEDs 18 can be soldered to the circuit board 16. In the example shown, however, the circuit board 16 has plug-in sockets 24 into which the LEDs 18 can be individually plugged. This has the advantage that defective LEDs can be replaced individually, so that if one LED fails, the entire lighting device does not need to be replaced.

In a modified embodiment, the circuit board 16 can also be curved or made of flexible material, so that special lighting effects can be achieved by curving the circuit board and changing the direction of the LEDs' radiation accordingly.

Figure 2 shows an embodiment in which a special housing for the lighting device is dispensed with. Instead, the LEDs are individually inserted into corresponding holes in the housing part 10. This allows the furniture manufacturer to determine the arrangement of the LEDs themselves, so that a high degree of design freedom is achieved. In the example shown, each LED 18 is held in a cylindrical holder 26 made of plastic, which is inserted into the hole in the furniture part 10 and has a collar 28 that limits the insertion depth. The holders 26 are plastic parts that can be mass-produced inexpensively and into which the contacts and supply lines 30 for the LEDs are injected. The holders are tapered at the free end so that they can be easily inserted into the holes in the furniture part. The supply lines are attached to the

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The LEDs are connected to electrodes 32 arranged on the outer circumference of the free ends of the sockets 26, which are contacted by a clamped-on plug 34. The plug 34 can be manufactured inexpensively as a continuous material and is clamped onto several sockets arranged in a row, so that a labor-saving electrical connection of the LEDs is made possible. The electronic control circuit for the LEDs can be housed in the plug 34 or in a separate housing that is connected by cable to the plug(s) 34.

Optionally, the sockets 26 can also have the same diameter as the LEDs 18, so that they can be inserted into the holes in the furniture part 10 from the rear. In this case, the free ends of the sockets can be firmly connected to the electronic control circuit via a cable harness formed by flexible cables.

Figure 4 shows an embodiment in which a housing 36, which only accommodates a single row of LEDs, is embedded in the furniture part 10. The end of the housing 36 protruding from the furniture part is connected to a plate or foil-like light guide 38, which lies flat against the surface of the furniture part 10. The light guide 38 has a curved reflection surface 40 at an end located inside the housing 36, on which the light from the LEDs is deflected by total reflection or by mirroring so that it falls into the plate or foil-like part of the light guide. The light is coupled out of the light guide by individual warts or ribs 42.

The lighting device according to Figure 3 thus forms an extremely flat surface light.

Alternatively, an elongated embodiment of the lighting device according to Figure 3 is also possible, in which a surface of the light guide 38 and a surface of the housing 36 lie in the same plane.

Alternatively, a fiber bundle can be used as a light guide or a light guide can be provided for each LED. However, the use of a flat light guide has the advantage that the light from the various LEDs overlaps, so that an even light distribution is achieved.

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is sufficient and differences in the color or brightness of the LEDs are better balanced. Since the LEDs form almost point-like light sources, they are particularly suitable for coupling light into a flat fiber-shaped light guide.

Figure 4 shows a schematic arrangement of the LEDs and the light guide, with which a particularly high luminance can be achieved. The LEDs 18 are held in a holder (not shown) in such a way that they are staggered in a plane that runs obliquely to the parallel optical axes of the LEDs. The light guide has a coupling surface 44 for each LED or LED row, which runs at right angles to the optical axis, and a reflection surface 46 that runs obliquely to the optical axis. The reflection surfaces deflect the light from all the LEDs 18 in such a way that it falls in a bundled form into a thin plate- or foil-like part of the light guide.

The LEDs, the associated socket and the coupling part of the light guide can be housed in a compact housing. The light can be guided to the desired exit point in the flat part of the light guide. The flat part of the light guide can also be curved or contain prisms to deflect the light, so that the configuration can be adapted to the respective conditions. The light can be emitted either as in Figure 3 through warts or ribs distributed over the surface of the light guide or at the front of the light guide. In the latter case, a decorative light strip with high luminance is obtained.

Claims (10)

TERMEER STEINMEISTER & PAI?TN£R *G?P *..* * I!**..* HLMPOl/98 PROTECTION CLAIMS 1. Furniture with lighting device, characterized in that the lighting device (12) is an array of light-emitting semiconductor elements (18). 2. Furniture according to claim 1, characterized in that the semiconductor elements (18) are arranged on a common circuit board (16). 3. Furniture according to claim 2, characterized in that the semiconductor elements are held individually replaceable in plug-in sockets (24) on the circuit board (1.6). 4. Furniture part according to claim 2 or 3, characterized in that the plate (16) is curved or flexible. 5. Furniture part according to one of claims 1 to 4, characterized in that the semiconductor elements (18) are accommodated in a housing (14; 36) which is embedded in a furniture part (10). 6. Furniture according to claim 1, characterized in that the semiconductor elements (18) are held individually in separate bores of a furniture part. 7. Furniture according to claim 6, characterized in that each semiconductor element (18) is arranged at the end of a cylindrical socket (26) which is inserted into the bore of the furniture part (10). 8. Furniture according to one of the preceding claims, characterized by a light guide (38) for transmitting the light from the semiconductor elements (18) emitted light. 9. Furniture according to claim 8, characterized in that the light guide (38) is a surface light guide. 10. Furniture according to one of the preceding claims, characterized in that the semiconductor elements (18) emit white light.