EP2161497A1 - Lighting unit - Google Patents

Abstract

The lighting unit has a free space (5) formed through an edge surface (3a) of a multi-layered, plate-shaped, transparent construction element (3) e.g. glass disk. A lamp (1) e.g. LED, is arranged and retained in the free space. The lamp is aligned with the edge surface such that light emitted by the lamp is irradiated by the edge surface and is directionally discharged via a plate surface of the construction element. The construction element is provided with a light control surface and/or a coating (3c) at a light discharge surface (3b).

Description

The invention relates to a lighting unit with at least one lamp and with a substantially plate-shaped, transparent construction element, in particular a glass pane, with an edge surface and two opposite plate surfaces, wherein by the edge surface of the construction element, a free space in the alignment of the construction element is formed and wherein at least one lighting means is arranged substantially in the free space and is held in the free space.

When presenting high-quality objects, such as exclusive pieces of furniture, clocks, jewelery or works of art, it is crucial to create suitable lighting conditions in order to optimally emphasize the value of the object in order to win the interest of potential customers. Glass showcases are particularly suitable for this purpose, as they allow a viewing of the presented object from several sides and the perfect surface of the glass structural elements used, be it vertically oriented side walls or floors, together with the presented object create an appealing overall picture.

For illuminating the presented object lamps are preferably used, which are arranged on the display case itself, so as to be able to illuminate the presented object from a short distance and thus high light intensity. It should be noted that the Bulbs themselves occupy only a small volume of construction, so that they do not obstruct the view of the object partially or by their existence partially distract from the presented objects. Furthermore, it must be avoided that a part of the light is directed in the direction of the viewer and thus distracts from the presented objects.

Halogen reflector lamps, which produce a bright light, are therefore unsuitable for direct mounting on the showcase in many cases. In addition, the high proportion of heat in the radiation of incandescent lamps can permanently damage sensitive objects, such as works of art or perfume bottles.

In contrast, LEDs are due to their small size particularly suitable for direct mounting on showcases or showcases. Furthermore, light-emitting diodes are characterized by a high light yield, high available light output with steadily decreasing prices, and by a light spectrum coming closer and closer to the natural white light. They are therefore increasingly used for lighting purposes in showcases, shop fitting or in the presentation of furniture, for the reasons mentioned above usually a combination with glass is chosen.

In currently available solutions, the LEDs themselves are very much in the foreground, ie the LEDs themselves are in the field of view of the beholder. This with regard to the overall objective, namely an appealing presentation of a valuable object to However, due to the novelty of LED technology, it is generally not considered problematic at present. However, in the future, it is expected that light-emitting diodes are increasingly used as ordinary light sources, and therefore the requirement is made to visually recede into the background as the light source itself.

In the illumination of showcases using LEDs different solutions are known from practice. In a first known solution ( Fig. 1 ) facing the viewer edge surface of a glass with a the edge surface covering sheet metal profile, which in turn protrudes beyond the edge surface provided. In this case, a number of light-emitting diodes are arranged in the projecting beyond the edge surface portion of the sheet metal profile, illuminate the items placed in the showcase, but are hidden from the viewer's direction by the sheet metal profile. The problem here is on the one hand, that the light emitting diode is offset from the edge surface of the glass, which widens the edges of the glass pane in an optically unfavorable manner and partially restricts the viewer's view of the illuminated object. In addition, the diodes are exposed to pollution unprotected.

In another solution ( Fig. 2 ), a glass pane installed in a showcase has a beveled edge surface facing the viewer, which is adjoined by another elongated, beam-like glass element with a likewise beveled side surface. On the surface facing away from the viewer, a plurality of light-emitting diodes are arranged, which contain the object stored in the showcase From the viewpoint of the viewer from oblique front illuminate. Since the light-emitting diodes are arranged on a glass component, they are visible from the direction of the viewer, which is disadvantageous for aesthetic reasons. Although non-transparent or partially transparent glasses can be used to avoid visibility, in this case the additional glass element restricts the view of the illuminated object and the exposed LEDs are permanently exposed to contamination as in the first solution.

Based on this, the present invention seeks to provide a lighting unit with at least one lamp and a substantially plate-shaped, transparent construction element, in particular a glass pane of the type mentioned above, which allows effective and effective lighting of objects and goods from the viewer's line of sight in which the illuminant used should be largely protected against contamination and the illuminant attaches to the structural element without affecting the aesthetics of the structural element.

The object is achieved with a lighting unit according to the preamble of claim 1, characterized in that the at least one light source is aligned to the edge surface of the structural element out such that the light emitted by the light source is irradiated via the edge surface in the structural element and on a plate surface directed out of the construction element again exits.

The particular advantage of the illumination unit according to the invention is that the radiation angle of the radiation emitted by the illuminant and transmitted through the transparent construction element to the object to be illuminated can be varied over a wide range by a specific relative orientation of the illuminant and the edge surface in compliance with Snell's law , Without the bulbs must emerge from the escape of the structural element, which gives the lighting unit a particular aesthetics compared to the known solutions and improves the viewing possibility of the illuminated object. In this case, the angle of irradiation to the solder of the plate surface is referred to as the light exit surface, below which the light of the at least one luminous means emerges from the transparent constructional element. By means of a specific variation of the emission angle, in turn, the irradiation of the light onto the object to be illuminated can be finely adjusted in the desired and aesthetically pleasing manner.

The fact that the radiation emerges directed from the construction element again, a direct and particularly effective lighting of objects in the vicinity of the lighting unit can be achieved.

In particular, in the case of particularly compact bulbs, such as light-emitting diodes, the light source can easily accommodate in the space formed by the edge surface of the structural element in its flight clearance.

Due to the fact that the luminous means is oriented towards the edge surface and thus radiates into the edge surface of the transparent constructional element, the luminous means is largely protected against contamination and, moreover, can be encapsulated in relation to the environment.

As a plate-shaped, transparent construction element preferably glass or Plexiglas panes are used, which are particularly suitable for the presentation of high-quality objects. Single-pane safety glass (ESG) can also be used in potentially accident-prone applications, such as showcases in very busy department stores.

Also, transparent construction elements with a slightly different surface from a completely flat surface are understood as construction elements in the context of the invention, as far as the material of the construction element for the light emitted by the light source is transparent. A strict parallelism is not crucial here.

According to a first embodiment of the invention, the free space is formed by a provided in the edge surface of the structural element bevel surface. As a chamfer surface is here considered a surface which is formed at an acute angle to the actual surface of the structural element in this in the edge region of the plate-shaped construction element. This does not necessarily have to be an area subsequently formed in the construction element. Likewise, the free space can also be formed by a molded into the edge surface Be formed stage. However, the particular advantage of a chamfer surface lies in the fact that it can be incorporated into an edge surface comparatively easily and with machines usually present in the glass-working industry.

In the illumination unit, the intensity maximum of the exiting light is determined by the position of the at least one luminous means relative to the chamfer surface. With the relative positioning of the luminous means to the chamfer surface of the constructional element, the angle of incidence of the intensity maximum of the light emitted by the luminous means into the chamfer surface is set. If, for example, the light emitted by the light source is radiated perpendicular to the chamfer surface and this has approximately an angle of 28 ° relative to the surfaces of the plate-shaped construction element, so the light occurs on the chamfer surface opposite the plate surface of the structural element at an angle of approximately 45 ° to the surface of the construction element, so that if the construction element is a glass side wall or a glass bottom of a display case, the object to be illuminated can be placed in the usual way in the center of such a display case and thereby optimally illuminated.

According to a further embodiment of the invention, the construction element is formed multi-layered and the free space formed by at least one recessed layer of the construction element. Of course, the individual layers may in each case also be formed with a chamfer surface. Multilayer, transparent construction elements are known in many embodiments. For example, the multilayer Design element designed as a composite safety glass (VSG). In this case, in a horizontal arrangement of the VSG, the upper glass layer can be set back and thus form the space in which the light source is arranged and held. The light source in turn can be aligned such that it radiates into the projecting lower glass surface and this radiates. One possible application is to provide overhead glazing, which must be properly designed as laminated safety glass, such as a glass canopy or a glass pergola, with such lighting.

In order to adjust the relative position of the luminous means to the edge surface of the transparent construction element precisely, according to one embodiment of the invention it is provided that the luminous means comprises an adjustment mechanism, so that the position of the luminous means is attached to a certain extent independently of the respective component to which it is attached, can be adjusted.

As light source light sources of various types can be used. For example, it is possible for the luminous means to be designed as an incandescent lamp, preferably as a plurality of incandescent lamps in the form of a light string or a light tube. It is also possible to provide the lighting means as a light guide, which is connected to a light source external to the lighting unit. However, particularly preferred is the use of a light-emitting diode, in particular a plurality of light-emitting diodes arranged on a common strip. These are characterized, as mentioned above, by small size, low Energy consumption and high light output on a small volume with a natural light spectrum.

In order to obtain a desired intensity distribution in the luminous means, it can also be useful to associate with the luminous means for beam shaping a micro-optic which, for example, collimates the beam cone emitted by a point light source or focuses or bundles it with a sufficiently long focal length.

According to a further embodiment of the invention, the construction element at the light entrance and / or light exit surface is partially provided with a light-scattering surface in the form of a surface roughening and / or coating. If the light-scattering coating is arranged in the beam path of the at least one luminous means, it advantageously serves to slightly widen the intensity distribution of the light exiting from the constructional element and thus to illuminate a larger area without the light losing its characteristic as directionally propagating light Another aesthetic advantage is that a direct view of the bulbs - for example, by mirroring the bottom of the lighting unit on a glass surface arranged below the lighting unit - the viewer is denied due to the turbidity of the light exit surface.

A particularly high luminous efficacy with respect to an object to be illuminated by the illumination unit is achieved when the light-scattering surface is arranged at the light exit surface (plate surface), the proportions of the light irradiated by the at least one luminous means into the structural element at an angle of incidence which is greater than or equal to the critical angle of total internal reflection on the light exit surface can escape from the structural element again. If the light-scattering coating is arranged exclusively in the region of total reflection of the light irradiated into the construction element, an increase in intensity of approximately 10% can be achieved in the light emerging from the construction element according to the Applicant's investigations. This can be used to illuminate an object to be illuminated even brighter or to reduce the light output of the at least one light source.

A further gain in intensity can be achieved in that the light from the interior of the glass pane drops below the Brewster angle to the boundary surface defined by the light exit surface between the transparent plate-shaped construction element and the surrounding air. In this case, the light components with aligned parallel to the plane of incidence polarization according to the brewster's law is not reflected back into the interior of the glass.

According to a particularly preferred embodiment of the invention, the edge surface of the structural element along its longitudinal extent is at least partially bordered by a profile element, wherein the profile element encloses the free space together with the structural element, in which the at least one light source is arranged. The use of such a profile element allows on the one hand, or to hide the light itself before the viewer and also to give the edge surface of the structural element by selecting a correspondingly shaped profile element a particularly aesthetic appearance. Such a profile element is preferably made of metal, in particular of stainless steel. It is also possible to manufacture the profile element of a synthetic or fiber material. In addition to an aesthetic manifestation, the arrangement of the lamp or bulbs in the free space between the edge surface and the inner surface of the profile element prevents soiling or damage to the lamp or lamps due to the ingress of moisture. Conveniently, the lighting means is attached to the profile element by gluing. This creates a particularly effective heat transfer into the profile element.

In addition, if the profile element in turn adhered to the structural element, so it can derive the heat absorbed by the one or more bulbs heat to the structural element partially. For example, if the lamp is an LED strip which is glued to a metal profile on the inner surface, wherein the metal profile is in turn glued to a glass sheet as a construction element, effective cooling of the LEDs is achieved in that their heat in derived the metal profile and is partially forwarded from there into the glass.

In general, the profile element and the structural element glued to it are made of different materials, so that when heating the composite material in the operation of the lighting unit on the different Thermal expansion of the materials involved is pay attention. If the construction element is, for example, a glass pane and the profile element is a metal profile, then the profile element should be made sufficiently thin and thus yielding, so that the shear stresses in the adhesive layer do not exceed a critical value. Also, the shear stresses in the adhesive layer can be minimized by choosing a suitable compliant but sufficiently strong adhesive. Furthermore, the thickness of the adhesive layer must be sufficiently uniform and must not fall below a minimum value. For example, the adhesive layer should be in a glass-metal composite in the range of 80 to 120 microns.

A continuous adhesive layer along the entire extent of the adhesive bond can be achieved according to a further embodiment of the invention in that the adhesive used spacers are added, which serve to adjust the minimum thickness of the adhesive layer. These are evenly distributed on the adhesive surfaces during application of the adhesive and ensure that the required minimum thickness of the adhesive layer is not undershot. Preferably, the spacers are formed as microspheres. For a layer thickness in a glass-metal composite of 80 to 120 microns, the microspheres typically have a mean diameter of 80 ± 1.5 microns.

In the lighting unit such adhesives are preferably used, which form a completely transparent layer in the cured state and thus the aesthetic impression also at the joints between Profile element and construction element preserved. In order not to worsen the transparency of the cured adhesive, it is therefore crucial that the microspheres are not visible in the adhesive as such and thus do not cloud this.

This can be achieved according to a further teaching of the invention in that the spacers are made of a polymer plastic whose refractive index substantially corresponds to that of the actual adhesive. As a result, a Mehrfachlichtbrechung- and reflection in the adhesive layer is avoided, so that the transparency of the adhesive layer is still guaranteed.

Another advantage of polymeric microspheres is that they can undergo a shrinkage process induced, for example, by UV curing of the adhesive, which can be approximately 3 - 5% in thickness, approximately 8% in volume, so that no visible microcracks occur occur in the adhesive layer due to stresses occurring between the shrinking adhesive and the microspheres. The usual proportion of the microspheres in the total volume of the adhesive is typically about 0.01% by volume.

Alternatively or in addition to an adhesive connection, the profile element can embrace the construction element according to a further embodiment of the invention and be frictionally connected to the structural element by clamping. In particular, in an exclusively caused by clamping connection between the profile element and the structural element, it is easily possible that Temporarily remove profile element for maintenance and / or repair of the lamp or lamps.

A special embodiment of the invention provides in this case that the strength of the clamping by adjusting screws, with which the profile element depressed at least on one side of the transparent construction element, is adjustable. In particular, the profile element may have a plurality, in particular regularly arranged along its longitudinal extent, flange portions with which the screws are screwed. As a result, over the entire longitudinal extent of the profile element finely adjustable clamping is realized.

Additionally or alternatively to the above, it is also possible to connect the profile element at least one of its two longitudinal ends via an end cap with the construction element. About such end caps, it is also possible to achieve an end-side sealing of the at least one bulb receiving volume.

Another aspect in the design of the lighting unit is the realization of a power supply for the at least one light source. It can be provided according to a further advantageous embodiment of the invention that the electrical conductors are arranged to supply energy to at least one edge surface of the plate-shaped construction element. For example, this very thin metal strips in question, which are glued flat on the edge surface of the structural element. This has the advantage that the entire visible surface of the construction element - About a glass pane - is not affected by visible on the surface of the structural element electrical conductor.

The power supply described above along the edge surfaces is independent of the lighting unit explained above and constitutes a separate invention.

In the following the invention will be explained in more detail with reference to a drawing illustrating an embodiment.

Show it:

Fig. 1

a lighting unit known from the prior art in a schematic cross-sectional view,

Fig. 2

a further known from the prior art lighting unit in a schematic cross-sectional view,

Fig. 3

a lighting unit in a schematic cross-sectional view,

Fig. 4

a lighting unit in one too Fig. 3 alternative embodiment in a schematic cross-sectional view,

Fig. 5

the lighting unit off Fig. 3 in perspective view,

Fig. 6

a lighting unit with a profile element in to Fig. 3 modified embodiment in perspective view,

Fig. 7

a lighting unit with a profile element in to Fig. 3 again modified embodiment in a schematic cross-sectional view,

Fig. 8

the lighting unit off Fig. 3 with a profile element fastened and sealed by end caps to the construction element, in a schematic side view,

Fig. 9

the lighting unit off Fig. 8 in plan view,

Fig. 10

the lighting unit off Fig. 3 with a beam-emitting surface partially provided with a light-scattering coating,

Fig. 11a, b

two polar diagrams for showing the rotation of the intensity maximum of the on the chamfer surface of the lighting unit according to the invention from Fig. 3 falling light at a chamfer angle of about 28 °,

Fig. 12a, b

the shear stresses occurring in the adhesive layer between a metal profile and a glass sheet,

Fig. 13

a showcase or a shop fitting for the presentation of high-quality goods in the form of a shelf, with a lighting unit according to the invention integrated in the shelves, in a schematic side view,

Fig. 14

another showcase or another shop fitting with integrated in the side walls lighting unit according to the invention in plan view and

Fig. 15

a glass canopy of a residential building with a lighting unit according to the invention in side view.

In Fig. 1 is a known from the prior art lighting solution for showcases and the like. shown in cross section. In detail shows Fig. 1 a glass pane 30 as a side wall or shelf of a glass showcase, in whose extension an open profile is arranged, which protrudes parallel to the edge surface 30x of the glass pane 30 over this. In this area, a luminous means 10 is arranged, which is aligned such that it (not dargstellt) directly illuminated the presented in the display case object. Like in the Fig. 1 shown structure is directly apparent, the bulb 10 is not protected against contamination and damage due to penetrating moisture. Further, hiding the bulb 10 is possible only by an optically unfavorable broadening of the profile perpendicular to the extension of the glass sheet 30 and by a bent end portion at the free profile end 20a, which is the Contemplation of the illuminated object limits.

When in the Fig. 2 illustrated, known from the prior art lighting solution is provided on the chamfered edge surface of a glass pane 30 * another glass element 40 * also beveled edge surface, on whose side facing the object to be illuminated a light source, in the present case a light emitting diode 10 *, is arranged. A disadvantage of this solution is that the light source 10 * is visible to the viewer and, in turn, no protection against the ingress of moisture or dirt is provided. When using non-transparent glass for back-lamination of the illuminant, the field of view of the viewer is severely limited.

In Fig. 3 is now a lighting unit according to the invention with different, the invention advantageously further developments embodiments shown in a schematic cross-sectional view. It comprises a luminous means 1, in the present case a plurality of light-emitting diodes arranged on a strip 1a (cf. Fig. 4 ), which preferentially emit white light. The light impinges on a plate-shaped transparent construction element, in the present case a glass pane 3, a chamfer surface 3a defining an open space 5 arranged in alignment with the glass pane 3 as the edge surface of the glass pane 3 and emerges from the glass pane 3 on its opposite side, the plate surface 3b , directed again. The glass pane can be designed as a single-pane safety glass (ESG).

The lighting unit further comprises a profile element, which in the present case is designed as a stainless steel profile 2.

The profile has a first flange portion 2b, which is aligned parallel to the top of the glass sheet 3 and is firmly connected thereto via an adhesive joint 4. The profile 2 also has a second section 2c, which is aligned parallel to the chamfer surface 3a, so that the light-emitting diodes 1, which are also fastened to the inside via the common strip 1a by gluing, project into the chamfer surface 3a perpendicular to the chamfer surface 3a. The light-emitting diode strip 1a, however, can in turn also be provided with an adjusting mechanism (not shown) by means of which the relative position of the light-emitting diodes 1 to the chamfer surface 3a can be precisely adjusted so that a strict parallelism between the chamfer surface 3a and the corresponding section 2c of the profile 2 also does not have to be present if a vertical direction of irradiation is desired. Finally, the profile 2 also comprises an L-shaped section 2a, which surrounds the glass pane 3 at its underside.

The presently selected chamfer angle of α = about 28 ° allows for vertical light irradiation in the chamfer surface 3a a radiation angle of the directed radiation from the glass sheet 3 of β = about 45 °, in each case based on the maximum intensity of the emitted light emitting diodes 1 (see , Fig. 11a, 11b ). By a variation of the angular position of the light-emitting diode 1 on the one hand or the angle of the chamfer surface 3a on the other hand, now the beam angle β can be as angle of the light emerging from the glass 3 to the Lot of the light exit surface 3b in vary within a wide range, so that in a provided with the lighting unit according to the invention glass cabinet can be set by the directed out of the construction element light optimal lighting conditions. Another advantage of the lighting unit of the Fig. 3 is that of the profile 2 of the space 5 is enclosed, which is according to the invention in the alignment of the glass sheet 3 and in which the light emitting diode strip 1a, 1 can be accommodated easily, which in particular by the encapsulation in the profile element 2 simultaneously from moisture and Pollution is permanently protected. The veneering of the usually green glass edge surface by an aesthetically sophisticated metal profile also enhances the appearance of the metal, while the metal profile also acts as a shock absorber. Since, as already mentioned, the light-emitting diodes are arranged in alignment with the glass pane 3, and thus the lighting unit does not widen the edge of the glass pane 3 in a bead-like manner, a compact, high-quality lighting solution thus results.

The Figures 11a and 11b now show in polar representation the winding position of the intensity maximum of the approximately Gaussförmigen beam distribution of the light emitted by the light emitting diodes 1 when entering the glass sheet 3 via the chamfer surface 3a (Fig. 6a ) and at the exit from the glass sheet 3 over the surface 3b. According to Fig. 6a enters the light of the diodes 1 with its intensity maximum at an angle of incidence of 0 °, ie perpendicular to the chamfer surface 3a, in the glass 3 and leaves it over the plate surface 3b as a light exit surface at a selected chamfer angle of α = about 28 ° at the opposite Surface 3b at an exit angle β of about 45 °, as in Fig. 11b shown. The rotation of the exit angle by about 45 ° with respect to the entrance angle can therefore be by the angle α of the chamfer surface 3a relative to the surface of the glass 3 as well as by adjusting the position of the LEDs 1 relative to the chamfer surface 3a, ie by adjusting the beam entry angle set precisely.

In the lighting unit of Fig. 3 is the light-emitting diode strip 1, 1a connected to the profile 2 by an adhesive bond. The profile 2 is glued in turn via an adhesive connection 4 with the glass pane 3. This results in a total of a solid bond between light emitting diodes 1, 2 profile and glass pane 3, which allows effective cooling of the light emitting diodes 1. They release a portion of the heat produced by them via the adhesive bond to the metal profile, which partially transfers the heat via the adhesive bond 4 to the glass pane. In this case, however, occurs heating of the metal profile 2 relative to the glass pane 3, which leads due to the greater thermal expansion of the metal of the profile 2 relative to the glass sheet 3 to shear stresses in the profile 2 with the glass pane 3 connecting adhesive joint 4. However, these remain below a critical value if the metal profile 2 has a sufficiently large compliance by a correspondingly thin-walled, filigree structure and, accordingly, a sufficiently yielding but nevertheless solid adhesive is selected. A suitable adhesive is marketed, for example, by Bohle AG under the product designation LV 740.

The in the Figures 12a and 12b The diagrams shown show the shear stresses occurring in the adhesive layer 4 according to a simulation calculation for a 0.5 mm thick stainless steel profile of length 1000 mm and the width (in the unbent state) of 24 mm at a temperature increase relative to the glass sheet 3 of 20 K. The thickness of Adhesive layer 4 was set at 80 microns with a width of the adhesive bond of 8 mm. The result of the simulation calculation is in Fig. 12a shown in an overview, wherein on the abscissa half the length of the 1000 mm long metal profile, ie the distance of the simulation point is plotted from the longitudinal center of the profile. As in the diagram of the Fig. 12a shown, the shear stress in the adhesive layer in the longitudinal center of the stainless steel profile is zero and increases only beyond a distance of 400 mm to the longitudinal center of the profile appreciably.

As in the enlarged detail of the Fig. 12b shown, the voltage increases between a distance of 450 mm to a longitudinal end of the metal profile (distance = 500 mm) from a value of 0.5 N / mm ² to a final value of 4 N / mm ² at. This value is still well below a critical threshold, which is about 20 N / mm ² in the above-exemplified adhesive LV 740. Even at a distance from the longitudinal end of the metal profile of less than 20 mm, the tension in the adhesive layer drops below 50% of the final value, as in Fig. 7 easy to read.

Overall, the documented in Fig. 12 illustrated simulation calculation that the bonding at the ends of the metal profile must be carried out very carefully.

However, it is a prerequisite that the thickness of the adhesive layer does not fall below a minimum value of 80 μm, in particular at the ends of the profile, over the entire length and width of the adhesive bond. This can be achieved in an advantageous manner by adding microspheres as spacers between the joining partners to the adhesive, which are uniformly dispersed in the adhesive and thus evenly distributed on the adhesive surface, whereby a punctiform undercut of the required minimum thickness of the adhesive layer is effectively prevented. The microspheres expediently have an average diameter of 80 μm with a fluctuation width of approximately 1.5 μm. An admixture of 0.01% by volume has proved sufficient in investigations by the Applicant. In order to obtain the complete transparency of the adhesive layer even when admixing the microspheres, the microspheres are in the present case made of a polymer plastic, so that their refractive index is virtually indistinguishable from that of the surrounding adhesive. As a result, light refractions and reflections are often avoided within the adhesive layer and thus prevents an optical unfavorable clouding thereof.

In Fig. 4 is one too Fig. 3 illustrated alternative embodiment of the illumination unit according to the invention. As a transparent construction element, it comprises a double-layered laminated safety glass (LSG) 300. In this case, the upper layer 310 is set back relative to the lower layer 320, whereby a free space is formed in the alignment of the VSG pane 300 by the stepped common edge surface of the layers 310, 320 , In this is the luminous means, in the present case again a plurality of light-emitting diodes 100 arranged on a common strip (not shown in detail), are arranged and held by gluing on the inner surface of a profile 200.

The light-emitting diode 100 shown is aligned in such a way that the emitted light enters the projecting section of the lower glass layer 320 and exits at the lower side as a light exit surface 320b.

The profile 200 is opposite to the profile 2 of FIG. 3 slightly different. It in turn comprises a section 200a, which extends this time to the underside of the glass pane 300, but this does not surround. At the edge termination of the profile section 200a, the clearance 500 in which the light-emitting diodes 100 are arranged is sealed by a bead-like layer 400a of a rubber-like adhesive. Due to the high elasticity of this adhesive layer 400a, no appreciable stresses arise between the glass 300 and the profiled end 200a at the comparatively thin lower edge region of the glass layer 320. Further, the adhesive layer 400a provides complete sealing of the clearance 500 so that moisture can not penetrate. The property of profile element 200 Fig. 4 , the glass pane 300 does not surround, can also on chamfered slices, as in Fig. 3 represented, transmitted. In this case, a rubber-like adhesive is again preferably used on the flange section 200a for sealing the free space formed between the profile and the glass pane.

In FIG. 5 is now a further embodiment of the lighting unit of Fig. 3 shown. The Embodiment relates to a particularly advantageous type of power supply to the light-emitting diode strip 1, 1a. The power supply is designed as a flat metal strip 6, in particular as a copper and stainless steel strip, which is guided at the upper edge of the lighting unit on the upper edge surface of the glass pane 3 and connected in the region of the chamfer surface by a short connection cable 6a with the light emitting diode strip 1, 1a is.

Other ways of securing the profile element 2 to the glass sheet 3 as a construction element are in the Fig. 6 to 9 shown.

Fig. 6 shows a perspective view of the lighting unit according to Fig. 3 In detail, the profiled element 2 has at its glass portion 3 the L-shaped encompassing portion 2a a plurality of regularly arranged along its longitudinal extension flange portions 2d on. The flange portions 2d each have a threaded opening in which adjusting screws are screwed, the controlled profile section 2a over the entire longitudinal extension of the profile 2 for the purpose of precise adjustment of the clamping force of the glass 3. As a result, a secure, uniform acting over the entire length of the profile element and structural element clamping connection is realized. The clamp connection according to Fig. 6 can be complementary to the in Fig. 3 shown adhesive bond 4 to occur.

According to Fig. 7 If the profiled element 2 'is embodied such that the free height bounded by the first flange section 2b' and the present angled flange section 2c 'is less than the thickness of the glass pane 3. Correspondingly, a non-positive connection, ie a clamping connection, results between the profiled element 2 ', and the glass sheet 3, as this bends the profile element 2' when inserted into the profile element 2 '. As a result, the profile element can be easily removed temporarily for maintenance and / or repair of the lighting device or 1. Again, the adhesive bond may be added to the adhesive bond (not shown).

The 8 and 9 relate to a lighting unit after the Fig. 3 in which the profiled element 2 is secured to the glass pane by means of end caps 2e, which are each pushed onto the glass element 3 oriented profile element 2, possibly additionally. Furthermore, the end caps serve to seal the volume between profile 2 and glass 3 frontally.

A particularly advantageous modification of the lighting unit Fig. 3 is in Fig. 10 shown in a schematic cross-sectional view. Here, a strip of a light-scattering coating 3c extending parallel to the glass edge is provided on the lower plate surface 3b of the glass pane 3 extending parallel to the glass edge to produce a locally light-scattering surface. The coating strip 3c has the function which is incident on the light exit surface 3b from the inside at an angle of incidence θ, which in this case is greater than the critical angle θ of the total reflection of the light irradiated by the LEDs 1 into the glass pane 3 at the light exit surface 3b from the glass pane 3 as scattered light, so that the portion of the light intensity reflected back into the glass pane 3 is minimized. Investigations by the applicant have shown that an intensity gain of approximately 10% can thus be achieved with the light emerging from the glass pane 3. Further meets the light from the interior of the glass under the Brewster angle to the defined by the light exit surface 3b interface between the glass 3 and the surrounding air, so the lights with aligned parallel to the plane of incidence polarization according to the brewster's law not back into the glass - or, in general terms, the transparent plate-shaped construction element - reflected, which allows a further gain in intensity.

In the embodiments of the FIGS. 13 and 14 glass showcases or shop components are now shown in a schematic view, which with lighting units according to Fig. 3 are provided. In case of Fig. 13 is a shelf shown with three glass shelves, in which in each of the two upper shelves facing the viewer B outer edge 9 as a lighting unit according to Fig. 3 is trained. The lighting unit thus irradiates the arranged on the underlying shelf in each case under a beam angle of about 45 ° and is not visible to the viewer B, while also does not hinder his field of view.

In the embodiment of Fig. 14 are the glass side walls of a showcase at their respective the viewer B facing edge with a lighting unit according to Fig. 3 Mistake. These in turn irradiate the object placed in the display cabinet at an illumination angle of 45 °, without restricting the field of vision of the observer.

In Fig. 15 Finally, a glass canopy of a residential building with a lighting unit according to the invention is shown in side view. The glass canopy is made of laminated safety glass Fig. 4 formed type and has a lighting unit according to Fig. 4 on. As a result, a good illumination of the entrance area of the house is achieved at the same time appealing design of the canopy due to the discreet placement of the lighting unit in the outer edge of the canopy.

Claims (15)

lighting unit - With at least one light source (1, 100) and - having a substantially plate-shaped, transparent construction element (3, 300) with an edge surface (3a) and two opposite plate surfaces, - Wherein by the edge surface (3a) of the construction element (3, 300) is a free space (5, 500) in the alignment of the structural element (3, 300) is formed and - wherein the at least one lighting means (1, 100) is arranged substantially in the free space (5, 500) and is held in the free space (5, 500), characterized in that - The at least one lighting means (1, 100) to the edge surface of the structural element (3, 300) out is aligned such that the light emitted from the light source (1, 100) light is radiated over the edge surface in the structural element and on a plate surface as Light exit surface directed out of the construction element again exits. Lighting unit according to claim 1,
characterized in that
the free space (5) is formed by a chamfer surface (3a) provided in the edge surface of the construction element (3). Lighting unit according to claim 1 or 2,
characterized in that
the construction element (300) is multi-layered and the free space (500) is formed by at least one recessed layer (310) of the construction element (300). Lighting unit according to one of claims 1 to 3,
characterized in that the at least one lighting means (1) for beam shaping is associated with a micro-optics. Lighting unit according to one of claims 1 to 4,
characterized in that the construction element (3) at the light entrance and / or light exit surface (3b, 320) is at least partially provided with a light-scattering surface in the form of a surface roughening and / or coating (3c). Lighting unit according to claim 5,
characterized in that the light-scattering coating (3c) is arranged on the light exit surface (3b) in such a way that the portions of the at least one light source impinging on the light exit surface (3b) at an angle of incidence greater than or equal to the critical angle of total internal reflection Construction element (3, 300) of incident light, escape from the construction element (3, 300) again. Lighting unit according to one of claims 1 to 6,
characterized in that the chamfer surface (3a) along its longitudinal extent at least partially by a profile element (2), in particular a metal profile, preferably a stainless steel profile, or a profile of a synthetic or fiber material, is framed, wherein the profile element (2) together with the construction element (3) encloses a free space (5), in which the at least one lighting means (1) is arranged. Lighting unit according to claim 7,
characterized in that the at least one lighting means (1) attached to the profile element (2), in particular glued. Lighting unit according to claim 7 or 8,
characterized in that the profile element (2) with the construction element (3) by means of an adhesive connection (4) is connected. Lighting unit according to claim 9,
characterized in that
the adhesive used contains spacers, preferably in the form of microspheres, for adjusting the minimum thickness of the adhesive layer, the spacers being made in particular of a polymer plastic. Lighting unit according to one of claims 7 to 10,
characterized in that
the profile element (2) the construction element (3) surrounds and is non-positively connected by clamping with the construction element (3). Lighting unit according to one of claims 7 to 11,
characterized in that the profile element (2) is connected at least one of its two longitudinal ends via an end cap (2e) with the construction element (3). Lighting unit according to one of claims 1 to 12,
characterized in that
the electrical conductors (6) for the energy supply of the at least one luminous means (1) are arranged on at least one edge surface of the plate-shaped construction element (3). Showcase, shopfitting or furniture element for the presentation of goods, in particular high-quality goods, such as jewelry, watches, works of art or the like, with at least one lighting unit according to one of claims 1 to 13. Glazing element, in particular glass canopy or pergola, with a lighting unit according to claim 3.

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