EP3108274A1

EP3108274A1 - Lighting device with a light guide plate and at least one luminaire

Info

Publication number: EP3108274A1
Application number: EP15707867.6A
Authority: EP
Inventors: Steven Schmidt; Ansgar NIEHOFF; Stefan Eibl; Jörg Goldstein
Original assignee: Rehau AG and Co
Current assignee: Rehau Automotive SE and Co KG
Priority date: 2014-02-19
Filing date: 2015-02-18
Publication date: 2016-12-28
Also published as: WO2015124296A1; DE202014100735U1

Abstract

The invention relates to a lighting device (10) with a light guide plate (12) and at least one luminaire (14). The light guide plate (12) has a circumferential lateral surface (16) and at least one light outlet surface (18). The luminaire (14) comprises at least one light-emitting diode (20) and at least one luminaire light outlet surface (22) for light (24) emitted by the light-emitting diode (20). The luminaire light outlet surface (22) faces the lateral surface (16) of the light guide plate (12) in order to couple the light (24) of the light-emitting diode (20) into the light guide plate (12). At least one means (26) is provided for coupling the light-emitting diode light (24) which has been coupled from the lateral surface (16) into the light guide plate (12) through the light outlet surface (18), and the luminaire light outlet surface (22) of the luminaire (14) rests against the lateral surface (16).

Description

Lighting device with a light guide plate and at least one lamp

Background of the invention

The present invention relates to a lighting apparatus having a light guide plate and at least one luminaire, wherein the light guide plate has a circumferential side surface and at least one light exit surface, wherein the luminaire comprises at least one light emitting diode and a light light exit surface for light emitted from the light emitting diode -Erittsfläche for coupling the light of the light emitting diode in the light guide plate faces the side surface of the light guide plate, wherein at least one means for coupling out of the side surface in the light guide plate coupled light emitting diode light is provided through the light exit surface therethrough.

In the known lighting devices of the type mentioned, the lights are spaced from the side surface and usually attached to a holding device, which is composed of a plurality of parts. As a result of this structure, the least possible loss of coupling of the light is limited. Further light-emitting devices provided with light-emitting devices having a structure differing fundamentally from the light-emitting devices of the type mentioned above are known e.g. from EP 2 444 230 A1, DE 10 2008 013 454 B4, DE 20 2010 000 342 U1 and DE 20 2012 01 1 498 U1.

Underlying task

It is an object of the invention to provide a lighting device, with which a low-loss coupling of the light is possible in the light guide plate. Inventive solution

This object is achieved with a lighting device having the features of the independent claim 1.

The lighting device according to the invention comprises a light guide plate or a translucent plate and at least one luminaire, wherein the light guide plate has a circumferential side surface and at least one light exit surface, wherein the luminaire comprises at least one light emitting diode and at least one luminous light exit surface for light emitted by the light emitting diode Luminaire light exit surface for

Coupling the light of the light emitting diode in the light guide plate faces the side surface of the light guide plate, wherein at least one means for coupling the coupled of the side surface in the light guide plate light emitting diode light or light of the light emitting diode is provided through the light exit surface.

In the case of the lighting device according to the invention, it is further provided that the luminous light exit surface of the luminaire bears against the side surface. In this way, in contrast to known lighting devices in which the lamps are spaced from the side surface and attached to a holding device, which is composed of a plurality of parts, a low-loss coupling of the light can be made possible in the light guide plate. Because the fact that the luminous light exit surface of the luminaire is applied to the side surface, a coupling of the light into the optical waveguide plate without large loss of light can take place, without that there is a large or substantial loss of the radiated light energy or radiation energy, for. as a result of scattering or reflections, or without the luminous flux emitted by the respective light-emitting diode being able to be deflected excessively or to a great extent away from the peripheral side surface of the lightguide plate.

The light exit surface can be provided on any partial surface of the surface or the entire surface of the light guide plate. In particular, the light exit surface may be provided on a light guide plate, which comprises two mutually opposite cover surfaces and the peripheral side surface, for example on one of the two cover surfaces. However, it is also conceivable, for example, for the light exit surface to be provided on the encircling side surface, specifically for example at an area or partial area of the circumferential side surface which is at a distance from another area of this side surface is, at which the coupling or irradiation of the luminaire light or LED light occurs.

The means for decoupling or deflecting the light-emitting diode light coupled in from the side surface into the light guide plate through the light exit surface can be any means which is set up for this decoupling or deflection of the light-emitting diode light. This agent may be e.g. to act a received in or on the light guide plate scattering body. In the light guide plate may be any light guide plate, which is at least partially or entirely translucent. The thickness of the light guide plate is for example less than 6 mm.

In particular, the light guide plate can at least partially consist of a matrix material, which preferably comprises those materials which are transparent in the visible range of the light, such as, for example, polycarbonate, polymethyl methacrylate, acrylate resins,

Methyl methacrylate-acrylonitrile-butadiene-styrene copolymers, acrylic ester-styrene-acrylonitrile copolymers, styrene-acrylonitrile copolymers, polystyrene, cycloolefin copolymers, polypropylene, liquid crystalline polymers, polyamides, polyphenylene sulfone, polysulfone, polyethersulfone, polyethylene terephthalate, polybutylene terephthalate, inorganic Glasses and / or mixtures and / or layer combinations thereof.

The effect of the light control and the efficiency of the light extraction can be increased by additional components in the matrix material or by scattering elements on the surface of the light guide plate.

Additional constituents in the matrix material are scattering particles, which are of spherical and / or elliptical and / or polyhedron-like form and have smooth and / or rough and / or micro-rough and / or microstructured and / or textured surfaces and / or combinations thereof.

It is particularly advantageous if the scattering particles in the matrix material of the light guide plate in the lateral extent <70 μιη with as narrow as possible particle size distribution in the range ± 20 μηι present.

As suitable scattering particles prove to be

Glass microspheres or hollow glass microspheres,

crosslinked polymer particles (eg polymethyl methacrylate particles, such as TECHPOLYMER MBX or MBP or MB-C), crosslinked polybutyl methacrylate particles (eg TECHPOLYMER BMX), or crosslinked acrylic esters (TECHPOLYMER ARX), crosslinked polystyrene (TECHPOLYMER SBX),

Polymethylsilsesquioxane microspheres (DIASPHERE, TOSPEARL),

Polymethylsilsesquioxane composite microspheres with alumina and / or titanium dioxide surface modification (KOBO).

In a preferred embodiment, the light guide plate has a plurality of means in the form of scattering bodies for coupling out the light-emitting diode light coupled into the light guide plate from the side face by scattering the coupled-in light at the scattering bodies. In this preferred embodiment, therefore, a plurality of means are provided for coupling or deflecting the coupled from the side surface in the light guide plate light emitting diode light through the light exit surface, wherein the light guide plate having these means and each means is in the form of a scattering body. The preferably in the light guide plate or in the material of

Scattering body recorded scattered light body allow effective coupling or redirecting of the side surface in the light guide plate coupled or irradiated light-emitting diode through the light exit surface, in particular by providing a large plurality of scattered in the light guide plate scattering bodies extending over a large light exit surface light exit can be realized, along with the creation of a perceived as pleasant light.

The scattering bodies may be any scattering bodies which are designed to effect or realize the decoupling or deflection by scattering action.

The diffusers are optical structures at which the incident light beam is deflected so that a directed and / or diffuse coupling out through the light exit side of the planar light guide, i. opposite, distal side takes place.

On the interpretation of the structure, a homogeneous light emission can take place.

In order to achieve the homogeneous light emission, the scattering bodies, which are located in an area close to the luminaire, are small in size and small in size in terms of their lateral extent and depth or height of the diffuser body. In order to achieve a uniform light extraction over the surface of the light guide plate and a homogeneous light impression, it is advantageous if the size and number of scattering elements increase with increasing distance to the light. The scattering bodies may be produced by etching and / or embossing and / or ablating and / or laser structuring and / or printing and / or screen printing and / or digital printing and / or transfer printing and / or embossing methods, in particular by means of a UV-curing coating, and / or Applying a thin layer (eg <500 pm), for example in the form of a film, which already has scattering bodies, and / or produced by combinations thereof.

The scattering bodies can be applied to the surface of the light guide plate and / or project as depressions in the surface and / or combinations thereof.

The scattering bodies are punctiform and / or diamond-shaped and / or elliptical and / or polygonal and / or polyhedral and / or prismatic and / or conical and / or partially spherical and / or cylindrical or have hybrid forms of this.

The scattering bodies can have smooth and / or micro-rough and / or textured surfaces.

It is advantageous if the scattering bodies have heights of 20 to 200 pm. For punctiform and / or prismatic structures, the lateral extent is ideally between 10 pm and 6 mm. Scattering bodies, which are applied as printing ink and / or as a UV-curing coating, have as matrix material acrylate resins and / or urethane resins and / or

Urethanacrylatharze and / or polyester resins and / or epoxy resins and / or

Epoxy acrylate resins and / or hybrid resins, such as known from so-called ORMOCER coating systems on.

The scattering bodies can be transparent and / or have additives which have an increased refractive index relative to the matrix material of the light guide plate. The selection of additives includes pigments such as titanium dioxide, zinc sulfide, zinc oxide, barium sulfate and barium titanate, as well as particles such as glass, alumina, silicate, glass microspheres, hollow glass microspheres, crosslinked polystyrene particles, silver nanoparticles and chalk.

The luminaire light exit surface is preferably provided on at least one connecting layer of the luminaire, via which the luminaire is connected to the side surface, or the side surface preferably has at least one connecting layer, via which the luminaire or the light light exit surface is connected to the side surface. Over a Such connection layer can be created an effective coupling of the light-emitting exit surface to the side surface.

Preferably, the connecting layer establishes a material-locking connection between the luminaire-or the luminaire light exit surface of the luminaire-and the side surface, wherein the connecting layer is preferably a highly transparent adhesive layer. By a cohesive connection, in particular by a cohesive connection produced by means of a highly transparent adhesive layer advantageously a very effective coupling and thus also a very low-loss coupling of the light on the circumferential side surface or of the circumferential side surface by irradiating the same with the light-emitting diode light can be realized ,

Particularly preferably, the connection layer consists of a material composition having a refractive index which lies in a range between the refractive index of the luminous light exit surface and the light guide plate. Ideally, the refractive index is between 1, 2 and 1, 8.

By thus provided matching or match the refraction or reflection of the light-emitting diode light at the interface of compound layer and circumferential side surface or light guide plate can be advantageously avoided or substantially reduced, along with a very low-loss coupling or irradiation of light in the light guide plate.

Furthermore, the bonding layer is characterized in that the highly transparent adhesive layer is a thermal and / or chemical and / or radiation-curing system. Chemically curing systems include polymerization reactions and / or polyaddition reactions and / or polycondensation reactions and / or hydrosilylation reactions and / or crosslinking reactions.

Radiation-curing systems are in particular photochemically curing systems which cure in UV light and / or NIR light.

The bonding layer is characterized in that the curing of the highly transparent adhesive layer takes place at temperatures between 0 ° C and 120 ° C, preferably between 20 ° C and 85 ° C. In the context of the invention, it has proven to be advantageous if the connection layer is chosen such that

the adhesive strength of the highly transparent adhesive layer on the light guide plate> 0.5

N / cm is,

the adhesive strength of the highly transparent adhesive layer on the luminous light exit surface is> 0.5 N / cm,

the adhesive strength of the highly transparent adhesive layer on the luminaire housing, which is usually produced in polyphthalamide LEDs, is> 0.5 N / cm.

At least one of the above criteria must be fulfilled, ideally all three criteria are met.

The highly transparent adhesive layer has a light transmittance, that is, a transmittance in the visible region of the light, which is> 94%.

The highly transparent adhesive layer is advantageously designed as a permanently elastic compound layer in order to protect the luminous light exit surface from thermal stresses caused by the temperature difference between the luminaire and the light guide plate.

The highly transparent adhesive layer is to avoid light reflections and to achieve high adhesion from a minimum single-layer structure.

In order to achieve a better adhesion between light guide plate and light light exit surface, it may be necessary to pretreat the surface of the light guide plate by a corona and / or plasma activation.

The tie layer is a highly transparent tie layer. The width of the connection layer is also approximately equal to the width of the luminous light exit surface of the luminaire.

It can be arranged approximately plane-parallel between the luminous light exit surface of the luminaire and the circumferential side surface of the cuboid light guide plate with a layer thickness <100 μm.

However, it is advantageous if the side surface of the light guide plate, which is located at the connecting layer between the light emitting exit surface and light guide plate, toward the light light exit surface as a curvature in the form of an approximately semicircular in cross section. and / or approximately semi-elliptical and / or approximately semi-oval and / or trapezoidal prismatic structure and / or formed in a mixed form thereof.

This curvature on the side surface of the light guide plate in combination with the highly transparent adhesive layer has the advantage that light losses due to light extraction can be avoided by light extraction in the edge region of the light guide plate, caused by the wide radiation angle of the light emitting diode.

The material composition of the highly transparent adhesive layer comprises at least one binder, at least one adhesion-promoting constituent to the light-emitting exit surface and / or the light guide plate, additives for increasing tack, and additives for refractive index modification.

Binders of the tie layer may be selected from:

Acrylates, urethanes, polyesters, polyethers, urethane acrylates, cyanomethyl acrylates, cyanoethyl acrylates, cyanomethyl methacrylates, cyanoethyl methacrylates,

(Meth) acrylic acid derivatives, epoxy resins, silicones, silicone copolymers, linear or branched Vinylhydrogenpolysiloxanen and / or mixtures thereof.

Adhesive constituents of the bonding layer to the luminous light exit surface and / or to the light guide plate can be selected from hydrophilic and / or organofunctional silicone copolymers, silicone-containing graft copolymers, linear or branched silicone block copolymers, branched polysiloxanes, silicone-containing gels, silicone-containing prepolymers, vinyl-functional polysiloxanes, SiH- functional polysiloxanes, silazanes and / or mixtures thereof.

Examples are organopolysiloxane-polyurea block copolymers, organopolysiloxane-polyurethane block copolymers, silicone-modified polyacrylates, silicone-modified

Urethane acrylates, polyether-modified silicones, silicone-polyacrylate hybrids with additional reactive groups, such as hydroxyl and / or epoxy and / or carboxyl and / or amino and / or vinyl groups in the polymer chain.

Tackiness increasing components of the tie layer may be selected from silanes, siloxanes, silazanes, silane terminated and / or silylated polyethers,

silane-terminated and / or silylated polyurethanes and silane-terminated and / or silylated polyacrylates. Silanes are to be understood as examples:

Allyltrialkoxysilanes, allyldialkoxysilanes, allylmonoalkoxysilanes, undecenyltrialkoxysilanes, vinyltrialkoxysilanes, vinyldialkoxysilanes, vinylmonoalkoxysilanes, tetraalkoxysilanes, trialkoxysilanes, glycidyloxypropylalkoxysilanes, carbamates, aminosilanes and 3-mercaptopropyltrialkoxysilanes.

Examples for this are:

Vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltris (2-methoxyethoxy) silane, vinyltris (2-ethoxyethoxy) silane, vinyldimethylmethoxysilane, vinyldimethoxysilane, vinylphenyldimethoxysilane, vinylphenyldiethoxysilane,

Vinyldiethoxysilane, vinylmethyldiethoxysilane, vinylphenylmethylmethoxysilane,

Allyltrimethoxysilane, allyldimethoxysilane, allylmethyldimethoxysilane, allyltriethoxysilane, allyldimethoxysilane, allylmethyldimethoxysilane, Allyldiethoxysilan, allylmethyldiethoxysilane, Undecenyltrimethoxysilan, Allyloxyundecyltrimethoxysilan, 1, 3-Diallyltetramethyldisiloxan, vinyltriacetoxysilane, 1, 3-divinyltetramethyldisiloxane, vinyltetramethyldisiloxane, 1, 3- divinyltetraphenyldisiloxane, 3-glycidyloxypropyltrimethoxysilane, 3- glycidyloxypropyltriethoxysilane, N-trimethoxysilylmethyl O-methyl carbamate, N-dimethoxy (methyl) silylmethyl-O-methyl carbamate, N-methyl [3- (trimethoxysilyl) propyl carbamate, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (n-butyl) aminopropyltrimethoxysilane, bis (3-triethoxysilylpropyl) amine, bis (3-trimethoxysilylpropyl) amine and oligomeric amino / alkylalkoxysilanes. Siloxanes are to be understood by way of example:

Polydimethylmethylhydrogensiloxanes, trimethylsiloxy-terminated

Dimethylsiloxane copolymers, hydrido-terminated polydimethylsiloxanes,

trimethylsiloxy-terminated polymethylhydrosiloxanes, linear α, τσ-dihydropolydimethylsiloxanes, cyclic polymethylhydrogensiloxanes, cyclic ones

Polydimethylmethylhydrosiloxanes.

Silanes are to be understood as examples:

Examples of additives for modifying the refractive index of the compound layer are nanoscale compounds and / or constituents, such as nanoscale particles and / or crystals, which consist of sols and / or gels and / or metals and / or metal oxides and / or metals. tallsulfiden and / or doped metal oxides and / or silicates and / or mixtures thereof.

The nanoscale compounds contain as metal and / or metal ion aluminum and / or iron and / or zinc and / or zirconium and / or silver and / or barium and / or titanium and / or magnesium and / or sodium and / or lithium and / or Copper and / or gold. Preference is given to using nano-silver and / or nano-titanium dioxide and / or nano-zirconium oxide and / or nano-zinc sulfide.

In a practical embodiment of the lighting device, this has a circumferentially extending around the light guide plate frame with a circumferentially around the

Side surface extending inner surface. On the frame or the inner surface of the lamp or the lights can be kept and mounted in a simple and practical way very reliable. In particular, by means of the frame a plurality of light-emitting diodes can be provided, which can be provided by attachment to the frame or the inner surface, e.g. particularly preferably along the circumferential extending side surface of the light guide plate can be arranged successively.

In particular, the frame may include a plurality of interconnected polymer profiles. Very stable and lightweight polymer profiles can be produced inexpensively by extrusion. In particular, by joining several polymer profiles e.g. a square or rectangular frame are created, the dimensions of which can be very well adapted to the dimensions of the respective light guide plate by appropriate length selection of the polymer profiles. A lightweight polymer profile of the frame consists of:

Polymethyl methacrylate and / or polycarbonate and / or polyamide and / or polypropylene and / or acrylonitrile-butadiene-styrene copolymer and / or polyethylene terephthalate and / or polybutylene terephthalate and / or polyvinyl chloride and / or a blend of polycarbonate and acrylic ester-styrene-acrylonitrile and / or a blend of polycarbonate and acrylonitrile butadiene styrene.

The lightweight polymer profile can also be particle and / or fiber-reinforced (glass fiber, carbon fiber) to increase the rigidity and optionally have flame retardant additives.

It is advantageous if the lightweight polymer profile additives for improving the thermal conductivity, such as boron nitride, barium sulfate, aluminum nitride, zinc oxide, Zinc sulfide, zirconia, wollastonite, chalk, carbon modifications or mixtures thereof.

The lightweight polymer profile may also have a decorative or lacquer layer based on acrylate and / or urethane acrylate. In addition to decorative purposes, this lacquer layer can also serve to improve the surface resistance, such as, for example, scratch resistance and / or resistance to cleaning agents and / or environmental influences.

The lightweight polymer profile preferably has a layer thickness of <4 mm. The frame may in particular be reinforced or mechanically reinforced by at least one reinforcing element, which may in particular be a band-shaped reinforcing element which is extrusion-coated and / or laminated and / or laminated. Along with a substantial increase in the stability of the frame or the lighting device can be created in particular by providing the polymer profiles together with the reinforcing element in comparison to known lighting devices with light guide plates, a much lighter and more compact lighting device. The reinforcing element can particularly advantageously at least partially consist of a metallic material, together with a very effective reinforcement. Furthermore, by providing a metallic material, a very effective heat dissipation and heat distribution of the heat produced during operation of the luminaires can be realized, which has a particularly advantageous effect on the life of the lamp or luminaires. A polymer profile with an extrusion-coated and / or laminated and / or laminated metallic reinforcing element can be particularly advantageous with processing processes customary in the furniture industry - e.g. known from editing furniture edges - be milled or milled for machining or shaping.

The metal reinforcement over the entire side surface of the polymer profile, the surface temperatures are kept much lower than 70 ° C, ideally less than 40 ° C, so that a touch of the lamp element in the area of the lamp is possible. Furthermore, the thermal expansion of the plastic component is limited by very effective surface heat dissipation and by the high rigidity of the metal reinforcement over the entire side surface of the polymer profile, thereby permanently outstanding dimensional stability is achieved even with temperature fluctuations between -20 ° C and +70 ° C.

In addition to the horizontal heat conduction from the luminaire to the metal reinforcement of the frame, a vertical heat conduction from the side surfaces / frame into the back side covering surface of the planar luminaire element, for which purpose a rear-side heat-conducting element is provided.

At the same time, the metal reinforcement dissipates the resulting heat into the room. The band-shaped reinforcing element of the frame consists of stainless steel and / or steel and / or copper and / or aluminum and / or alloys with copper. The layer thickness is about <1 mm.

In addition, it is advantageous if the band-shaped reinforcing element is completely coated on at least one side with an electrically insulating adhesive layer in order to realize on the one hand the adhesion to the polymer profile and on the other hand the adhesion to the luminaire.

The adhesion between frame and band-shaped reinforcing element is at least> 0.5 N / cm.

The adhesive strength between the band-shaped reinforcing element and luminaire is at least> 0.5 N / cm.

The adhesion promoter layer of the band-shaped reinforcing element consists of a co-extruded adhesion promoter layer based on maleic anhydride-grafted polypropylene and / or polyurethane and / or ethylvinyl acetate and / or ethyl acrylate.

The adhesion promoter layer of the strip-shaped reinforcing element consists of a coating based on 2K polyurethanes and / or epoxy resins and / or acrylate and / or urethane acrylate resins and / or cyanoacrylate resins and / or unsaturated polyester resins and / or phenolic resins and / or polyimide adhesives and / or cyanate resins and / or benzoxazine resins and / or hybrid resins and / or mixtures thereof. The thickness of the adhesion promoter layer is preferably approximately <0.2 mm.

Particularly preferably, the frame comprises a circumferentially extending around the light guide plate band, wherein one of the two opposite sides of the band forms a visible and circumferential outer surface of the lighting device. In this way, a visually very sophisticated lighting device can be provided, in which the peripheral outer surface in the form of a band side can cause a visually very appealing appearance. Particularly advantageously, the luminaires and / or other devices of the lighting device can be arranged between the other of the two opposite sides of the band and the peripheral side surface of the light guide plate, whereby the lights and / or the other devices in opaque or almost opaque formation of the band outside the lighting device are not visible, along with the creation of a visually appealing lighting device in which the light can escape only through or over the intended light exit surface and the intended light exit surfaces. The band may particularly preferably be an edge band.

For the processing of edgebands, there are established procedures in the furniture industry. The frame described here and the band-shaped metal reinforcement in combination with the intended luminaire or light-emitting diode arrangement can be processed easily and without damage with automated processes that are common in the furniture industry. It is particularly advantageous that with this arrangement radii and corners can be displayed. The frame described with its multi-layered construction can be set at angles less than or equal to 90 ° by notches and / or cuts in the polymer profile.

In addition, lips may be extruded to cover the margins or to enhance the hermetic encapsulation of the frame. The polymer profile of the frame is further characterized by easy weldability, which can be used to attach additional holders. In a practical embodiment of the lighting device, a preferably at least partially metallic reinforcing element or a preferably at least partially metallic planar reinforcing element can be attached to a surface of the light guide plate which is at a distance from the light exit surface or facing away from the surface or the entire surface of the light guide plate , The reinforcing element may particularly preferably be in the form of a plate-shaped reinforcing element or in the form of a foil-shaped or foil-like reinforcing element or in the form of a composite foil or a metal composite foil. In addition to the advantageous reinforcing effect can be realized by an at least partially metallic design of the reinforcing member a very effective heat dissipation and heat distribution of the heat generated during operation of the lights, which is particularly advantageous effect on the efficiency and the life of the lamp or lights. Further, by providing this reinforcing element, in particular also together with the above frame, a much lighter and more compact lighting device can be provided, in comparison with known light-guide plate lighting devices. The film-shaped reinforcing element and / or the composite film and / or the metal composite film preferably have a thickness or a material thickness which is less than 1 mm. In a particularly preferred embodiment of the lighting device, at least one luminaire with a plurality of light-emitting diodes and at least one tether with a first side, the front side, and a second side opposite thereto, the rear side, are provided, the luminaire with all light-emitting diodes exclusively at the front side the tether is attached. The front side of the tether has an upper and lower half in the longitudinal direction, with all light-emitting diodes being oriented in the upper half, preferably close to the longitudinal edge of the tether.

By providing the retaining band, a lighting device can be provided or created in a structurally simple manner, in which the lights or LEDs along the circumferential extending side surface of the light guide plate can be arranged successively, in such a way that the lights or light-emitting diodes preferably in the longitudinal direction the tether are arranged successively. For successively arranging the luminaires or light-emitting diodes along the circumferentially extending side surface of the lightguide plate, the tether is merely to be arranged or guided around the peripheral side surface or around the circumferential side surface in a simple manner.

In order to guide the edge band with light-emitting diode arrangement around corners, areas may additionally be provided on the holding band, which have no light-emitting diodes in the upper half of the front side, so that kinks can be formed.

The light-emitting diode arrangement is designed so that the distance between the half of the front side of the tether, which has the light-emitting diode arrangement, and the side surface of the light guide is defined by the component width of the light-emitting diodes. Preferably - in particular for the realization of the above successive

Arranging the light emitting diodes along the side surface - the second side of the tether attached to or adhered to the circumferentially extending inner surface of the above frame. The retaining band can preferably consist of a polymer material, in particular a thermoplastic and / or duromer material, in order, for example, to advantageously be able to form a stable adhesive bond or a material-bonding connection on the inner surface of the above frame. However, the tether can also be an electrically insulating coating on the band-shaped reinforcing element or an adhesive tape with or without fabric reinforcement.

In a practical embodiment, the light guide plate comprises two cover surfaces and the circumferential side surface, wherein the light exit surface is provided on one of the two - opposite - cover surfaces, wherein on the other cover surface, a plate-shaped or foil-shaped reinforcing member is mounted, and wherein the lower half of the front ( second side) of the tether is attached to a projecting and unconnected to the light guide plate portion of the reinforcing element. By attaching the retaining band to the projecting portion of the plate-shaped or film-shaped reinforcing element - see. Also, the above statements on the advantageous effects of such, preferably at least partially metallic reinforcing element - can be advantageously realized a structurally compact designed lighting device. Particularly advantageously, the retaining strip on conductors for energizing and / or driving the lamp and electronic devices for energizing and / or controlling the lamp on the tracks, wherein the circulating traces and the electronic devices only on the lower half of the front (first side) of the Holding straps are provided, and wherein the electronic devices are arranged spaced from the light. The fact that the circulating conductor tracks and the electronic devices are arranged only on the lower half of the front side (first side) of the tether, can advantageously of a complex or complicated connection or interconnection with many separate contacts, as known lighting devices with light guide plates is known to be apart. The retaining band can be arranged in a simple and practical manner along the circumferential side surface or guided along the circumferential side surface around the light guide plate, so that the contact advantageously has to be formed only once, along with a favorable reduction of the manufacturing effort. The fact that the electronic devices are arranged at a distance from the lamp has the advantage that these devices include the arrangement or mode of operation of the respective luminaire the luminaire light exit surface of the luminaire adjacent to the circumferential side surface does not hinder or disturb it.

A further advantage is that the positioning of the contacting points on the underside of the planar luminaire element and in the region of the frame makes it possible to produce a simple rear-side contacting which does not disturb the visual appearance in the region of the frame or the light exit surface. That is, the contacting takes place in a generally non-vision area. Likewise, other electronic components such as power supplies and / or DC converters and / or antennas and / or controllers and / or switches and / or sensors and / or control elements and / or transistors and / or resistors and / or memory elements can be provided at the height of the circulating conductor tracks. be attached.

In a further practical embodiment of the lighting device, the light guide plate comprises two cover surfaces and the circumferential side surface, wherein the light exit surface is provided on at least one of the two cover surfaces and / or on the side surface, wherein the light guide plate (or the lighting device) at least one means for Decoupling the light-emitting diode light coupled from the side surface into the light guide plate via the light exit surface - or through the light exit surface - on at least one of the two cover surfaces and / or at least one means for decoupling the light-emitting diode light coupled into the light guide plate via the side surface Light exit surface -bzw. through the light exit surface through - on the side surface.

By providing means for decoupling over the circumferential side surface and / or the at least one cover surface, a lighting device optimally adapted to desired requirements can be provided. So it can be e.g. be desired that the light is coupled out only over the side surface. One thinks for example: B. to a lighting device, which is provided as a shelf with a lighting functionality, in which the light emission is to take place exclusively on the side surface. In particular for this purpose as well, at least a portion of the frame may then be designed to be translucent at least in regions for passing the coupled-out light through the above frame.

The luminaire or the at least one light-emitting diode particularly preferably has a resin material which fills the gap between the holding strap with the light-emitting diode (s) and the light guide plate and possibly the carrier element into which the light-emitting diode oden or the at least one light emitting diode of the lamp and / or the curvature of the side surface of the light guide is embedded at least partially or entirely. In this way cavities are closed. With a resin material or cast resin material, the heat generated during operation of the lamp or lights can be advantageously dissipated well - in particular better dissipated than by air. The formation of so-called "hot spots" can be avoided.

In combination with the material-flush connection layer between luminaire or

Luminaire light exit surface and the side surface of the light guide plate is achieved with the likewise flush-mounted resin or Gießharzschicht that the beam path of the light is limited by the luminous light exit surface. Since there is no air gap or no loose contact between luminous light exit surface and light guide plate, almost no stray light losses occur. The resin or casting resin material contains at least one polymer and / or at least one prepolymer and at least one additive for heat conduction, optionally for pigmentation, as well as for reflection of the light beam. Resins or casting resins used are based on polyurethane elastomers and / or 2K polyurethane resins and / or epoxy resins and / or polyester resins and / or acrylate resins and / or are hot melt adhesives on the basis

Ethylene vinyl acetate and / or ethylene methyl acrylate and / or ethylene butyl acrylate and / or polyamide and / or styrene-containing copolymers and / or polyolefin and / or polyurethane and / or maleic anhydride-grafted polymers and / or are copolymers with maleic anhydride and / or crosslinked polymers. Additives for heat conduction and light reflection are boron nitride and / or barium sulfate and / or aluminum nitride and / or zinc sulfide and / or zirconium oxide and / or titanium dioxide.

According to the invention, the planar luminaire element in the region of the light exit surface is formed from a layered structure consisting of diffuser, light guide plate with structural layer, reflector and plate-shaped reinforcing element. In addition, a carrier element can additionally be located between the reflector and the plate-shaped reinforcing element.

Furthermore, it is advantageous that this layered structure is connected flush to the material in the region of the light exit surface. The interconnected layered structure in the region of the light exit surface advantageously causes, on the one hand, thermally induced deformations or even a detachment of individual layers and unwanted layers Avoid bulges when heated and on the other hand, a protection against the ingress of media is achieved.

The diffuser, also referred to as a scattering layer, can be formed as a UV coating with light-scattering particles and / or as a thin plate and / or as a semitransparent decorative film.

To cover the light-emitting diode arrangement and the region of the light guide plate in which the light cones of the light-emitting diodes do not overlap, the diffuser can have a reflective coating. This is particularly advantageous, on the one hand to realize a homogeneous light extraction via the lens and on the other hand to avoid a direct view of the light emitting diodes.

The reflector consists of a film, ideally metallic reflective and / or white reflective colored for light scattering and / or sections combinations thereof. The reflector can be glued as a film directly to the carrier material and / or the metal composite foil. The reflector can also consist of a coating and / or coating as coloring of the carrier element and / or the plate-shaped reinforcing element or the metal composite foil.

In order to create a compact component with good composite adhesion, it may additionally be advantageous if at least in sections there is direct adhesion between the reflector and the light guide plate.

The support member may be a wood board and / or chipboard and / or wood fiber board and / or MDF board and / or a wood-plastic composite plate and / or cork and / or a natural fiber board and / or a synthetic fiberboard and / or a honeycomb core of paper and / or inorganically filled paper and / or expanded glass and / or a fiber-reinforced composite material and / or glass and / or nonwoven and / or a textile carrier and / or a polyurethane foam and / or an expanded polypropylene (EPP) and / or an expanded polystyrene ( EPS) and / or a polymer material plate and / or a mixing or combination form thereof.

Brief description of the drawings

Exemplary embodiments of the invention will be explained in more detail below with reference to the attached drawing. In the drawing show: 1A is a schematic sectional view of a first embodiment of a lighting device with a sectional plane perpendicular to a top surface and parallel to two opposite partial surfaces of the circumferential side surface of a cuboid light guide plate of the lighting device,

Fig.l B is a very schematic three-dimensional representation of a light guide plate for

Illustrating the sectional plane of Fig. 1A, Fig. 2 and 4 are each a schematic sectional view of a retaining band with a

Luminaires, tracks and electronic devices;

3 shows a schematic sectional view of a second embodiment of a lighting device with a sectional plane as in FIG. 1A, FIGS. 5A-5C show a schematic plan view of a lighting device,

FIGS. 6A-6D respectively show a schematic sectional illustration along the sectional plane I or II according to FIG. 5B or FIG. 5C, and FIGS. 7A-7B respectively show a schematic sectional illustration of geometrical shapes of the side surface of a light guide plate with the connection layer or highly transparent adhesive layer and FIG adjacent LED.

The lighting apparatus 10 according to FIG. 1 comprises a light guide plate 12 and a luminaire 14 with a plurality of light-emitting diodes 20 or with a plurality of light-emitting diodes 20, wherein only one light-emitting diode 20 is shown in the sectional illustration according to FIG.

FIG. 1B illustrates the position or orientation of the sectional plane according to FIG. 1A. The sectional plane 58 is oriented at right angles to a cover surface 42 of two mutually opposite cover surfaces 42, 43 and parallel to two opposite partial surfaces 60 of the circumferential side surface 16 (see also FIG. 1A) of the parallelepiped light guide plate 12 of the lighting device 10.

The light guide plate 12 (see FIG. 1A) has the peripheral side surface 16 and, inter alia, a light exit surface 18 provided on the cover surface 42 of the light guide plate 12 on. Flatly connected to the top surface 42 is a diffuser 62, which is provided to homogenize the light emerging from the light exit surface 18 and further to make the diffusers 54 invisible from outside the lighting device 10. The light guide plate 12 is further attached to a support member 64, wherein at the

Cover surface 43 further comprises a structural layer 66 and a reflector 68 are provided, which are provided between the top surface 43 and the support member 64. The reflector 68 makes it possible to make the carrier element 64 invisible from outside the lighting device 10.

The luminaire 14 has, for each light-emitting diode 20, a respective light-light exit surface 22 for the light 24 emitted by the respective light-emitting diode 20. The luminous light exit surface 22 is for coupling the light 24 of the light emitting diode 20 in the light guide plate 12 to the peripheral side surface 16 of the light guide plate 12, wherein the umlau- fenden side surface 16 for coupling the light 24 of the light emitting diode with the light emitting diode 24 is irradiated ,

The light-emitting exit surface 22 of each light-emitting diode 20 is provided on each one of a plurality of connecting layers 28 of the lamp 14 through which the lamp 14 is connected to the side surface 16, wherein for each light-emitting diode 20 of the lamp 1 each have a connection layer 28 is provided. The connecting layer 28 is designed in the form of an adhesive layer and establishes a bonded connection between the luminaire 14 or the respective light-emitting diode 20 and the side surface 16.

The light guide plate 12 has a plurality of means 26 in the form of scattering elements 54 for coupling out the coupled from the side surface 16 in the light guide plate 12 light-emitting diode 24 through the light exit surface 18 therethrough, wherein the decoupling or deflection of the light-emitting diode light 24 by scattering of the coupled-in light 24 takes place at the scattering bodies 54. An attached to the underside of the support member 64 reinforcing element 44 in

The shape of a metal composite foil serves for the mechanical stabilization of the lighting device 10 and advantageously makes it possible to effectively dissipate the heat produced during operation of the luminaire 14. The lighting device 10 further comprises a circumferentially extending around the light guide plate 12 frame 30 with a circumferentially extending around the side surface 16 inner surface 32. The frame 30 is in the form of a rectangular frame 30 and comprises four interconnected polymer profiles 34, each arranged in pairs opposite one another (not illustrated in FIGS. 1A and 3). Each polymer profile 34 is reinforced by an extrusion-coated reinforcing element 72 in the form of a metal strip, wherein the inner surface 32 of the entire frame 30 is provided on the metal bands of the polymer profiles 34.

In addition to the rectangular shape, other shapes can be represented, such as round and / or elliptical and / or polygonal and / or mixed forms thereof.

The luminaire 14 with all light-emitting diodes 20 is mounted exclusively on a first side 38, the front side, of two mutually opposite sides 38, 40 of a retaining band 36, in the upper half and more preferably on the longitudinal edge of the tether, which is schematically schematic in section is also illustrated in Figure 2. The tether 36 has two tracks 48 for energizing and / or driving the lamp 14 and electronic devices 50 for energizing and / or driving the lamp 14 via the circulating conductor tracks 48. The circumferential conductor tracks 48 and the electronic devices 50 are provided only on the first side 38 of the retaining band 36 and the electronic devices 50 are arranged at a distance from the lamp 14. By arranging the retaining band 36 along the peripheral side surface 16 advantageously can be dispensed with a complicated interconnection and the lamp 14 advantageously with only two contacts 74 or terminals (see Fig. 1A) are operated. The second side 40 of the tether 36 is adhered to the inner surface 32 of the frame 30 by means of an adhesive layer 70 so that the tether 36 may extend along the peripheral side surface 16.

In the lighting device 10 according to FIG. 1A, the luminaire 14 has a resin material 56 into which the light-emitting diodes 20 of the luminaire 14 are at least partially embedded.

The luminous device 10 according to FIG. 3 differs from the luminous device 10 according to FIG. 1 in that it disregards the carrier element 64 and the second side 40 of the retaining strap 36, the rear side, on a protruding region 46 of the reinforcing element 44 in the form of the metal composite foil by means of an adhesive layer 76 is glued. Furthermore, in the lighting device 10 according to FIG. 3, the light-emitting diodes 20 of the luminaire 14 are rotated 90 degrees relative to the light-emitting diodes 20 of the luminous device 10 according to FIG. 1 - cf. Also, Figure 4, which shows a schematic sectional view of a retaining band 36 of the lighting device 10 of Figure 3. The mechanical stability is effectively provided by the plate-shaped reinforcing element 44 in the form of the metal composite film or metal plate or plastic-metal composite plate (thickness about <2 mm) in lighting device 10 of Figure 3, whereby in contrast to the lighting device 10 of Figure 1 is a very compact lighting device 10 is created. FIGS. 5A to 5C serve to illustrate further exemplary embodiments of lighting devices 10 which differ from one another by the localization of the light exit surface 18 or light exit surfaces 18 or the localization of the respective light coupling. Each of the lighting devices 10 according to FIGS. 5A to 5C has a cuboid light guide plate 12 and a frame 30 extending circumferentially around the light guide plate 12 with an inner surface 32 extending circumferentially around the respective side face 16 of the light guide plate 12. Each frame 30 is in the form of a rectangular frame 30 and comprises four interconnected polymer profiles 34, which are each arranged in pairs opposite one another. In the very schematic representations, the broadening of some polymer profiles 34 is merely the characteristic drawing of the fact that on or in the immediate vicinity of these polymer profiles 34, a tether with a lamp according to one of the above embodiments is provided.

In the case of the lighting device 10 according to FIG. 5A, a light exit surface 18 is provided on the cover surface 42 of the light guide plate 0 - cf. For this purpose, the course of the light 24 symbolized by the light rays out of the plane. The light coupling takes place exclusively via the left-hand rectilinear partial surface 60 of the circumferential side surface 16 of the light guide plate 12. The light coupling is effected via a multiplicity of means in the form of scattering elements (not illustrated here) for coupling out the coupled-in light-emitting diode light by scattering the coupled-in light the scattering bodies. The scattering bodies are accommodated in the light guide plate 12 (not illustrated) and also scatter the light toward the remaining polymer profiles 34. In order to avoid the light from escaping here, in the lighting device 10 according to FIG. 5A, the upper, lower and right-hand polymer profiles 34 are opaque. In contrast to the lighting device 10 according to FIG. 5A, in the case of lighting device 10 according to FIG. 5B, the light coupling additionally takes place via the right-hand rectilinear partial surface 60 of the circumferential side surface 16 of the light guide plate 12. In order to prevent the light from escaping via the upper and lower polymer profile 34, FIGS the lighting device 0 according to Figure 5B, the upper and lower polymer profile 34 opaque.

The lighting devices according to FIGS. 5A and 5B may in principle always be a lighting device 10 in the manner of the lighting device 10 according to FIG. 1A or FIG. In this respect, the sectional representation according to FIG. 6A very schematically illustrates the section along the sectional plane I (cf., FIG. 5B) by a lighting device 10 in the manner of FIG. 1A. The sectional view according to FIG. 6B illustrates the section along the sectional plane I through a lighting device 10 in the manner of FIG. 3. The lighting device 10 according to FIG. 5C differs from those according to FIGS. 5A and 5B in that no scattering bodies are provided here and the light extraction is substantially over the upper, lower and right polymer profile 34, as illustrated by the light rays of the light 24. For this purpose, the upper, lower and right-hand polymer profiles 34, which respectively represent sections 52 of the frame 30, each have a partial section or a region 78 (see also FIGS. 6C and 6D), which is designed to be translucent.

The lighting device according to FIG. 5C may in principle also be a lighting device 10 in the manner of the lighting device 10 according to FIG. 1A or FIG. In this respect, the sectional representation according to FIG. 6C very schematically illustrates the section along the sectional plane II (cf., FIG. 5C) by means of a lighting device 0 in the manner of FIG. 1A. The sectional view according to FIG. 6D very schematically illustrates the section along the sectional plane II through a lighting device 10 in the manner of FIG. 3.

Advantageously, for the integral connection of the partially transparent or translucent upper, lower and right polymer profiles 34 or the transparent areas 78 of these profiles 34 with the carrier element 64 or the light guide plate 12 (see FIGS. 6C and 6D), a laser light can be activated by laser light or translucent laser function layer may be provided (not illustrated). Of course, apart from the Lichteinkopplungsvarianten or Lichtauskopplungsvananten according to Figures 5A to 5C, any other variants are conceivable. In FIGS. 7A and 7B, the geometric shape of the side surface of a light guide plate 12 with the connection layer or highly transparent adhesive layer 28 and the adjacent light-emitting diode 20 is shown in a schematic sectional illustration.

The side surface of the light guide plate 12, which is located on the connection layer 28 between the light-emitting exit surface 22 and light guide plate 12 is formed towards the light exit surface 22 as a raised curvature in the form of a cross-sectionally approximately semicircular structure of FIG. 7A.

Other formations may be formed in cross-section as approximately semi-elliptical and / or approximately semi-oval and / or trapezoidal prismatic structure and / or in a mixed form thereof.

By this curvature on the side surface of the light guide plate 12 in combination with the highly transparent adhesive layer 28 light losses by light extraction in the edge region of the light guide plate 12, caused by the wide radiation angle of the light emitting diode 20 can be avoided by optimal light control.

FIG. 7B shows, in a schematic sectional view, the geometric shape of the side surface of a light guide plate 2 in a trapezoidal prismatic structure with the connection layer or highly transparent adhesive layer 28 and the adjacent light emitting diode 20.

LIST OF REFERENCE NUMBERS

10 lighting device

12 light guide plate

14 light

16 circumferential side surface

18 light exit surface

20 LED

22 luminaire light exit surface

24 lights

26 means for decoupling

28 bonding layer

30 frames

32 inner surface

34 polymer profile

36 holding strap

38 first page, front page

40 second side, back

42 deck area

43 deck area

44 plate-shaped reinforcing element 46 projecting area

48 circumferential tracks

50 electronic device

52 frame section

54 scattering bodies

56 resin material, casting resin material

58 cutting plane

60 partial area

62 diffuser

64 carrier element

66 structural layer

68 reflector

70 adhesive layer 72 band-shaped reinforcing element

74 contacting

76 adhesive layer

78 translucent area

Claims

claims

Lighting device (10) with a light guide plate (12) and at least one lamp (14), wherein the light guide plate (12) has a circumferential side surface (16) and at least one light exit surface (18), wherein the lamp (14) at least one light emitting diode (20 ) and at least one luminous-light exit surface (22) for light (24) emitted by the light-emitting diode (20), the light-emitting exit surface (22) for coupling the light (24) of the light-emitting diode (20) into the light guide plate (12). the side surface (16) of the light guide plate (2) facing, wherein at least one means (26) for coupling out of the side surface (16) in the light guide plate (12) coupled light emitting diode light (24) through the light exit surface (18) provided therethrough is, characterized in that the lamp light exit surface (22) of the lamp (14) on the side surface (16) is present.

Lighting device (10) according to claim 1, characterized in that the

Luminaire light exit surface (22) on at least one connecting layer (28) of the lamp (14) is provided, via which the lamp is connected to the side surface (16) or that the side surface (16) has at least one connecting layer (28), via which the lamp (14) is connected to the side surface (16).

Lighting device (10) according to claim 2, characterized in that the connecting layer (28) consists of a material having a refractive index, which lies in a range which lies between the refractive index of the luminous light exit surface (22) and the light guide plate (12), preferably, the refractive index is between 1, 2 and 1.8.

Lighting device (10) according to one of the preceding claims, characterized in that the lighting device (10) has a circumferentially extending around the light guide plate (12) frame (30) with a circumferentially around the side surface (16) extend-the inner surface (32) having. Lighting device (10) according to claim 4, characterized in that the frame (30) comprises a plurality of interconnected polymer profiles (34).

Lighting device (10) according to claim 4 or 5, characterized in that the frame (30) comprises a circumferentially around the light guide plate (12) extending band, wherein one of the two opposite sides of the belt has a visible and circumferential outer surface of the lighting device (10 ).

Lighting device (10) according to any one of the preceding claims, characterized in that at least one lamp (14) with the light-emitting diodes (20) and at least one tether (36) having a first side (38), the front side, and one opposite second side (40), the rear side, are provided, wherein the lamp (14) is attached to the one or more light-emitting diodes (20) on the first side (38) of the retaining band (36) at its longitudinal edge.

Lighting device (10) according to any one of the preceding claims, characterized in that the second side (40), the back, of the retaining band (36) on the circumferentially extending inner surface (32) is attached or adhered thereto.

Lighting device (10) according to one of the preceding claims, characterized in that the light guide plate (12) comprises two cover surfaces (42, 43) and the peripheral side surface (16), wherein the light exit surface (18) on one of the two cover surfaces (42) wherein a plate-shaped or foil-shaped reinforcing element (44) is attached to the other top surface (43), and wherein the second side (40) of the tether (36) is secured to an overhanging area (46) connected to the lightguide plate (12) ) of the plate-shaped reinforcing element (44) is mounted.

Lighting device (10) according to one of the preceding claims, characterized in that the holding band (36) circumferential conductor tracks (48) for energizing and / or driving the lights (14) and electronic devices (50) for energizing and / or driving the lamp ( 14) via the tracks (48), wherein the circulating tracks (48) and the electronic devices (50) only on the first side (38), the front side of the retaining band (36) in the lower Half are provided, and wherein the electronic devices (50) from the lamp (14) are arranged spaced.

Lighting device (10) according to one of the preceding claims, characterized in that the light guide plate (12) comprises two cover surfaces (42, 43) and the peripheral side surface (16), wherein the light exit surface (18) on at least one of the two cover surfaces (42, 43) and / or on the side surface (16) is provided, wherein the lighting device (10) at least one means (26) for decoupling from the side surface (16) in the light guide plate (12) coupled light-emitting diode light (24) via the Light exit surface (18) on at least one of the two cover surfaces (42, 43) and / or at least one means (26) for decoupling the from the side surface (16) in the light guide plate (12) coupled light emitting diode light (24) via the light exit surface ( 18).

Luminous device (10) according to any one of the preceding claims, characterized in that for passing the decoupled light (24) through the frame (30) at least a portion (52) of the frame (30) is at least partially translucent.

Lighting device (10) according to any one of the preceding claims, characterized in that the light guide plate (12) has a plurality of means (26) in the form of scattering bodies (54) for coupling out of the side surface (16) in the light guide plate (12) coupled light-emitting diodes Light (24) by scattering the coupled light (24) on the scattering bodies (54).

Lighting device (10) according to any one of the preceding claims, characterized in that the lamp (14) comprises a resin material (56), in which the light-emitting diode (20) of the lamp (14) is at least partially embedded.

Lighting device (10) according to any one of the preceding claims, characterized in that the connecting layer (28) produces a material connection between the light (14) and the light-emitting diode (20) and the side surface (16), wherein the connecting layer (28) preferably a highly transparent adhesive layer. Lighting device (10) according to one of the preceding claims, characterized in that a resin material or casting resin material (56) the space between the tether (36) with the one or more light emitting diodes (20) and the light guide plate (12) and optionally the carrier element (64). fills.