EP2518394B1 - LED light with equally bright light emitting surface - Google Patents

Description

The invention relates to a luminaire with an LED (LED: light emitting diode) and with a translucent cover, which has a first plane Lichtabgabefläche with a first surface normal, which points in a first direction and a second plane Lichtabgabefläche with a second surface normal, which in a second direction, which differs from the first direction, wherein the first plane light emitting surface is separated from the second planar light emitting surface only by an edge region.

With such a luminaire, it may happen that the light generated by the luminaire on the first or second planar light emitting surface appears inhomogeneous. In general, however, it is desirable that the light emitting surfaces appear as bright as possible.

From the WO 2010/117734 A2 is known according to the preamble of claim 1, an LED light with multiple light emitting surfaces. The light emitting surfaces are separated by a frame part made of aluminum.

The invention has for its object to provide a corresponding improved luminaire; In particular, the luminaire should - with good efficiency - can show a particularly homogeneous or uniformly brightened light emission surface.

This object is achieved according to the invention with the objects mentioned in the independent claims. Particular embodiments of the invention are indicated in the dependent claims.

According to the invention there is provided a luminaire having an LED and a translucent cover having a first plane light emitting surface having a first surface normal pointing in a first direction and a second plane light emitting surface having a second surface normal extending in a second direction that differs from the first direction; In this case, the first plane light emission surface is separated from the second plane light emission surface only by an edge region, wherein the edge region is formed as part of the cover and the cover consists of only one material. In this case, the lamp is designed such that a light emitted by the LED light the lamp at least partially on the first plane Light emission surface leaves. Furthermore, the lamp is designed such that the light emitted by the LED light causes a drop shadow that extends at least partially within the edge region.

Due to the fact that the drop shadow runs within the edge area, it can be avoided that it appears on the first flat light emission surface. This makes it possible to achieve that the first plane light emission surface appears particularly homogeneous. In addition, it can also be avoided in this way that the drop shadow appears on the second planar light emitting surface, whereby a particularly homogeneously illuminated second light emitting surface is made possible.

Preferably, the lamp also has a holding element, for example in the form of a housing of the lamp, wherein both the cover and the LED are each arranged directly or indirectly fixed in position on the holding element. This allows a comparatively simple construction of the luminaire.

Advantageously, the lamp also has further light emitting surfaces, wherein the second light emitting surface and the further light emitting surfaces are arranged such that they surround the first planar light emitting surface on all sides, in particular directly or only separated by edges or edge regions. This makes it possible that the light emits light in light emission areas both in the first direction, as well as to all sides around the first direction.

Furthermore, the luminaire has a luminaire component which is arranged such that the drop shadow is caused by an interaction of the light emitted by the LED with the luminaire component. In particular, the luminaire can be designed such that the luminaire component forms an operating device for operating the LED or at least partially roofs it. In this way, a negative effect of the luminaire component on the homogeneity of the light output can be reduced particularly effectively. This is the case in particular if the height of the luminaire along the first direction is comparatively small.

Advantageously, the lighting component is formed by a preferably roof, pyramid or conical reflector element. This can be a - with reference In the first direction in extension of the lamp component located, darkened spot on the first light emitting surface reduce - so relatively lighten - or even prevent practically.

Preferably, the lighting component is arranged in a projection along the first direction viewed in a central region of the first planar light emitting surface. This makes it possible that the light emitted by the LED light through one of the other light emitting surfaces unhindered exit and leave the light.

According to a further aspect of the invention, there is provided a luminaire having an LED and a translucent cover having a first plane light emitting surface having a first surface normal pointing in a first direction and a second plane light emitting surface having a second surface normal that faces into a first surface second direction, which differs from the first direction; In this case, the first planar light emitting surface is separated from the second planar light emitting surface only by an edge region, wherein the light is designed such that a light emitted by the LED light leaves the light at least partially over the first plane light emitting surface. In particular, it may also be a luminaire according to the invention with the above-mentioned features. Furthermore, the luminaire has a reflector element with a reflective surface, which directs the light emitted by the LED at least partially onto the first plane light emission surface.

The reflecting surface makes it possible to direct part of the light emitted by the LED by reflection on the reflecting surface in the direction of the first plane light emitting surface; in this way, an area on the first planar light emitting surface is supplied with light which would otherwise receive less light and thus appear as a dark spot on the first planar light emitting surface. The reflector element may be formed as described above. In particular, the lamp preferably further comprises an operating device for operating the LED, wherein, viewed in a projection along the first direction, the reflecting surface comprising the operating device and is arranged in a central region of the first planar light emitting surface. Advantageously, the reflective surface is roof-shaped, pyramidal or conical. In the case of a roof shape, the reflector element or the reflecting surface preferably has cut-out regions on the gable ends formed by the roof shape. In this way, it is possible to prevent an unwanted drop shadow from forming on the first plane of the light emission by the interaction of light from another LED with one of the ends of the gables.

The retaining element advantageously has a planar mounting surface, on which the LED is arranged, wherein the mounting surface has a recess, in particular a passage opening, wherein an operating device for operating the LED, the recess is arranged cross-through. The planar mounting surface is advantageously arranged oriented parallel to the first light emitting surface. In this way, the operating device is arranged "sunk" and thus forms a reduced impairment of a homogeneous light output.

According to yet another aspect of the invention, there is provided a luminaire having an LED and a translucent cover having a first planar light emitting surface having a first surface normal pointing in a first direction and a second planar light emitting surface having a second surface normal has a second direction that differs from the first direction; In this case, the first planar light emitting surface is separated from the second planar light emitting surface only by an edge region, wherein the light is designed such that a light emitted by the LED light leaves the light at least partially over the first plane light emitting surface. In particular, it may also be a luminaire according to the invention with the above-mentioned features. Furthermore, the lamp has a holding element with a planar mounting surface, on which the LED is arranged, wherein the mounting surface has a recess, in particular a passage opening, wherein an operating device for operating the LED, the recess is arranged cross-through.

Fig. 1

eine perspektivische Ansicht eines Ausführungsbeispiels einer erfindungsgemäßen Leuchte,

Fig. 2

eine schematische Querschnittskizze hierzu,

Fig. 3

eine Skizze einer Projektion der Leuchte längs der ersten Richtung und

Figuren 4a und 4b

Schnittdarstellungen zu Variationen mit einem "versenkten" Betriebsgerät.

The invention will be explained in more detail below with reference to exemplary embodiments and with reference to the drawings. Show it:

Fig. 1

a perspective view of an embodiment of a lamp according to the invention,

Fig. 2

a schematic cross-sectional sketch of this,

Fig. 3

a sketch of a projection of the lamp along the first direction and

FIGS. 4a and 4b

Sectional views of variations with a "recessed" control gear.

Fig. 1 shows a perspective view of an embodiment of a lamp according to the invention. The luminaire may in particular be a surface-mounted luminaire, for example a ceiling or wall surface-mounted luminaire.

For ease of description, a Cartesian coordinate system with the axes or directions x , y, and z defined thereby is selected, and in Fig. 1 indicated. The luminaire has a light-permeable, in particular opal cover 4, which has a first planar light-emitting surface 42. The first planar light output surface 42 has a first surface normal N1 , which points in a first direction, in the example shown in the direction x . Furthermore, the cover 4 has a second plane light emission surface 44 with a second surface normal N2 pointing in a second direction, here in the direction y . As in the example of the case, preferably the second surface normal N2 may include a right angle with the first surface normal N1 .

In addition, the lamp may have further, preferably also each planar light emitting surfaces 48, in the example shown, three further light emitting surfaces 48, wherein the further light emitting surfaces 48 and the second light emitting surface 44 are arranged such that they surround the first planar light emitting surface 42 on all sides. As shown, the further light-emitting surfaces 48 can each be planar and in the directions z, y and - have, for. The first planar light emitting surface 42 may be rectangular, for example square, and may be the largest of the aforementioned light emitting surfaces 42, 44, 48, so the light output of the luminaire in the first direction x can be referred to as the main light emission direction.

The first plane light emission surface 42 is separated from the second plane light emission surface 44 only by an edge region 46. The edge region 46 may in particular be a straight edge region 46. The second plane light emission surface 44 and the further light emission surfaces 48 can surround the first plane light emission surface 42 only by analogously formed further edge regions 50 or edges. Both the edge region 46 and the further edge regions 50 are likewise formed as part of the cover 4. In this case, the cover 4 consists of only one material.

Furthermore, the lamp may have a holding element 6, which may be, for example, a housing or a housing pan of the lamp. The holding element 6 can be configured for direct or indirect positionally fixed mounting of the cover 4.

Fig. 2 shows in schematic form a sectional view of the luminaire normal to the z-axis or in a plane defined by the first surface normal N1 and the second surface normal N2 level. It can be seen the cover 4 with the first planar light emitting surface 42, the second planar light emitting surface 44 and at the junction of these two surfaces said edge portion 46. Furthermore, one recognizes the holding element. 6

As in Fig. 2 by way of example, the luminaire also has an LED 2, the design being such that a light emitted by the LED 2 leaves the luminaire at least partially via the first planar light-emitting surface 42. The luminaire advantageously has at least one further LED 2 ', wherein a light emitted by this at least one further LED 2' also leaves the luminaire at least partially via the first planar light output surface 42. The luminaire is preferably the same or analogous with respect to the at least one further LED 2 'as with reference to the first mentioned LED 2.

Advantageously, the LED 2 is directly or indirectly fixedly connected to the holding element 6. In particular, accordingly, a fixed relative positioning between the LED 2 and the cover 4 can be ensured by the holding element 6.

As further schematically in FIG Fig. 2 sketched, the lamp is designed such that the light emitted by the LED 2 light causes a drop shadow S, which extends at least partially, in the example shown along the z-axis, within the edge portion 46.

The drop shadow S can in particular be caused by interaction of the light emitted by the LED 2 with a light component. The luminaire component may in particular be an operating device 8 for operating the LED 2, for example a corresponding converter. The operating device 8 may, for example, have an oblong edge 82, by the illustration of which the drop shadow S is formed.

As continues in Fig. 2 for clarity, the drop shadow S would not extend within the edge region 46 if the LED 2 were arranged at a certain other position L1 on the holding element 6. In the case shown by way of example, the drop shadow would in this case occur along a line S1 which is located outside the edge region 46 in a middle region of the first planar light emission surface 42; In this way, an inhomogeneity of the light output would be caused via the first plane light emitting surface 42. However, because the design is selected according to the invention in such a way that the drop shadow S extends longitudinally or within the edge region 46, this possible inhomogeneity can be avoided and thus a particularly homogeneous light output via the first plane light emission surface 42 can be achieved.

Accordingly, the arrangement is advantageously such that, viewed in the section shown, the edge 82 of the luminaire component lies on a straight line G both with the edge region 46 and with the LED 2.

Such a configuration is particularly advantageous if the light emits light not only in the first direction x , but also in the side on all sides extending directions y, z, and y - z, because in this case the operating device must be disposed in a central region 8, to allow a good light emission towards the sides. In this sense, further advantageous is the lighting component in a - sketch-like in Fig. 3 Projection along the first direction x viewed in a central region of the first planar light emitting surface 42 arranged.

A corresponding arrangement of the lighting component or of the operating device 8 in the central region is at unimpeded light output to the sides y, z, and y - z particularly advantageous when - in Fig. 2 The extension h of the lateral light emission areas 44, 48 in the first direction x is greater than the extension H of the luminaire in this direction, minus the corresponding extent b of the luminaire component or of the operating device 8.

Advantageously, the luminaire component can also be formed by a reflector element 10. In this way, it can be achieved that light which originates, for example, from the LED 2 or scattered light, is directed in the direction of the first planar light-emitting surface 42 by the reflector element 10. For this purpose, the reflector element 10 advantageously has a reflective surface 102. In this way, a region which is given by projection of the luminaire component or the reflector element 10 along the first direction x onto the first plane light emission surface 42 can be particularly illuminated. In this way, it is possible to reduce the likelihood that a much darker spot, a "dark spot" is created or becomes recognizable in this projection area on the first planar light emitting surface 42. The effectiveness of the luminaire can be improved by the said reflection effect.

In principle, it would of course also be possible with respect to the first direction x "on" the light fixture 8, 10 to provide a further LED for emitting light via the first plane light emitting surface 42. However, this is particularly problematic in the case in which the lamp has a comparatively low height H , or more precisely formulated, if the extension b of the lamp component 8, 10 compared to the height H of the lamp is comparatively large, because this would be due to great proximity of this hypothetical LED to the first plan Light emitting surface 42 lead to a punctual brightening on this light emitting surface 42 and thus again oppose a homogeneous light output.

Accordingly, the LED 2 is advantageously arranged in the projection mentioned within the first planar light emitting surface 42 but outside the reflector element 10 or at least outside the reflective surface 102. As in the Figures 2 and 3 sketched out, the LED 2 can be arranged in this sense immediately "next to" the reflective surface 102. However, the said advantageous effect can also be achieved if the LED is arranged at a certain distance from the reflector element 10 or the reflecting surface 102; this is in Fig. 3 outlined with reference to an exemplary LED 22 shown.

Preferably, the reflector element 10 or the reflective surface 102 is roof-shaped, pyramid-shaped or conical. In this case, the reflector element 10 advantageously extends from the retaining element 6 in the direction of the first planar light-emitting surface 42. For example, the holding element 6 may have a planar holding surface 62, preferably aligned parallel to the yz plane or the first planar light emitting surface 42, wherein the LED 2 and / or the reflector element 10 are arranged on the holding surface 62.

In the in the Figures 2 and 3 As shown by way of example, the reflecting surface 102 is roof-shaped and has a gable area 104 which points in the direction of the first plane light-emitting surface 42. With its - with reference to the drawing - right half of the reflective surface 102 is inclined relative to the yz plane by the angle w2 = = 15 °. If the LED 2 now has a half-value angle α = 120 ° (symmetrical about the first direction x ), on the one hand a portion of the light emitted by the LED 2 outside the half-value angle α reaches the reflecting surface 102, on the other hand general scattered light and so on The light reflected on the reflective surface 102 is at least partially directed onto the first planar light emitting surface 42 by the reflection.

If the LED were located at the point L1 as described above, the angle of the light from this hypothetical LED, which would cause the shadow S1 , would include an angle w1 = 30 ° with the yz plane.

In the example shown - with reference to the sectional view of Fig. 2 - The right half of the reflective surface 102 plan and thereby inclined so that it runs along the straight line G. In this way, with a comparatively small total extension of the reflector element 10 along the direction y, light can pass from the LED 2 into the edge region 46.

The said advantage of the reflector element 10 can of course be achieved independently of the above-mentioned embodiment of the drop shadow S in the edge region 46. However, both features mentioned are provided in the example shown, so that can be realized in this way with good lighting efficiency, a particularly homogeneous light output.

As already mentioned, a total of several LEDs can of course be provided as the light source of the luminaire, with the totality of the LEDs providing the most homogeneous possible light output via the first planar light emitting surface 42 and also via the second and the further, ie the "lateral" light output surfaces 44, 48 should be achieved. As in Fig. 3 By way of example, a further LED 24 may be provided in a corner region of the mounting surface 62 for illuminating a corner region. In the case of a roof-shaped reflector element 10, a further LED 26 may be provided, which is arranged at a location in extension of the reflector element 10 along the gable region 104 on the support surface 62. In the example shown, the gable region 104 is oriented along the direction z, and the further LED 26 is arranged at a location in the direction z viewed from the reflector element 10.

In the Fig. 3 sketched placement of the other LEDs 22, 24, 26 is suitable for homogeneous illumination of - with reference to the drawing - left lower quarter of the lamp or cover. For homogeneous light output over all light emitting surfaces, this arrangement or placement can be provided analogously in the other three quarters.

If the roof-shaped reflector element 10 viewed along the first direction x would be rectangular shaped, it could happen that - as indicated by the dotted arrow P - a radiated light from the other LED 26 by interaction with the pointing in the direction z edge 106 of Reflector element 10 causes an undesirable quasi "triangular" drop shadow on the first planar light emitting surface 42. It is therefore advantageous to provide a cutout or a cutout region 108 around the two-sided end regions of the gable region 104.

A further homogenization of the light output can be achieved if the mounting surface 62 has a recess, in particular in the form of a passage opening, wherein the operating device 8 is arranged so as to cross over this recess in the first direction x . The operating device 8 can accordingly be arranged "sunk" in part in the support surface 62, so that a negative influence on a homogeneous light emission of the luminaire by the operating device 8 has already been reduced in this respect.

Fig. 4a by way of example shows a sectional view normal to the first direction x, with a corresponding recess 64 in the form of a through-opening, Fig. 4b an embodiment with an alternative form of the passage opening 64th

Said advantage of the recessed arrangement of the operating device 8 can of course be achieved independently of the above-mentioned embodiments of the drop shadow S and the reflector element 10. However, two of the three or even all three mentioned features can be provided, so that in turn can be realized in this way a particularly homogeneous light output.

Claims (12)

1. A luminaire having

   - an LED (2),

   - a light-permeable cover (4) which has a first planar light-emitting surface (42) with a first surface normal (N1) pointing in a first direction (x) and also a second planar light-emitting surface (44) with a second surface normal (N2) pointing in a second direction (y) that differs from the first direction (x), wherein the first planar light-emitting surface (42) is separated from the second planar light-emitting surface (44)'merely by an edge region (46),

   wherein the luminaire is configured in such a way that a light radiated from the LED (2) leaves the luminaire at least in part by way of the first planar light-emitting surface (42),
   characterised in that
   the edge region (46) is formed as part of the cover (4), and the cover (4) consists of only one material,
   the luminaire is configured, moreover, in such a way that the light radiated from the LED (2) brings about, as a result of interaction with a luminaire component, a cast shadow (S) that extends at least in part within the edge region (46).
2. A luminaire according to claim 1,
   having, furthermore,

   - a holding element (6), for example in the form of a housing of the luminaire,

   wherein both the cover (4) and the LED (2) are in each case arranged directly or indirectly in a positionally secure manner on the holding element (6).
3. A luminaire according to claim 1 or 2,
   having, furthermore,

   - further light-emitting surfaces (48), wherein the second planar light-emitting surface (44) and the further light-emitting surfaces (48) are arranged in such a way that they surround the first planar light-emitting surface (42) on all sides, in particular directly or so as to be separated from each other only by edge regions.
4. A luminaire according to one of the preceding claims, having, furthermore,

   - a luminaire component (8, 10) which is arranged in such a way that the cast shadow (S) is brought about by interaction of the light radiated from the LED (2) with the luminaire component (8, 10).
5. A luminaire according to claim 4,
   which is configured in such a way that the luminaire component (8, 10) constitutes an operating device (8) for operation of the LED (2) or at least in part roofs over such a device.
6. A luminaire according to claim 4 or 5,
   in which the luminaire component is formed by a preferably roof-shaped, pyramidal or conical reflector element (10).
7. A luminaire according to one of claims 4 to 6,
   in which the luminaire component (8, 10), viewed in a projection along the first direction (x), is arranged in a central region of the first planar light-emitting surface (42).
8. A luminaire according to claim 6,
   in which the reflector element (10) has a reflective surface (102) which directs the light radiated from the LED (2) at least in part onto the first planar light-emitting surface (42).
9. A luminaire according to claim 8,
   having, furthermore,

   - an operating device (8) for operation of the LED,

   wherein, viewed in a projection along the first direction (x), the reflective surface (102) is arranged so as to surround the operating device (8), and thus in a central region of the first planar light-emitting surface (42).
10. A luminaire according to claim 8 or 9,
    in which the reflective surface (102) is roof-shaped, pyramidal or conical and in the case of a roof shape preferably has regions (108) that are cut out at the gable ends formed by the roof shape.
11. A luminaire according to claim 2 or a claim dependent on claim 2,
    in which the holding element (6) has a planar supporting surface (62) on which the LED (2) is arranged, wherein the supporting surface (62) has a recess (64), in particular a passage opening, wherein an operating device (8) for operation of the LED (2) is arranged so that it passes through the recess (64).
12. A luminaire according to claim 11,
    in which the planar supporting surface (62) is arranged so that it is oriented parallel to the first light-emitting surface (42).

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