EP2989379A1

EP2989379A1 - Luminaire for generating direct lighting and indirect lighting

Info

Publication number: EP2989379A1
Application number: EP14718087.1A
Authority: EP
Inventors: Helmut Feuerle; Marcel KILGA; Michael Spiegel; Andreas Schwaighofer
Original assignee: Zumtobel Lighting GmbH Austria
Current assignee: Zumtobel Lighting GmbH Austria
Priority date: 2013-04-24
Filing date: 2014-04-16
Publication date: 2016-03-02
Also published as: WO2014173769A1; CN105121950A; DE202013101772U1; US20160062030A1; US10408990B2

Abstract

A luminaire for generating direct lighting (D) and indirect lighting (I) comprises an LED light source (2) for generating light and a light guide plate (3) having a first main surface (31) and a second main surface (32), which is connected to the first main surface (31) marginally via a narrow side face (33), wherein the LED light source (2) is arranged in such a way that the light is radiated into the light guide plate (3) via the narrow side face (33) and subsequently one part of said light is emitted for generating the direct lighting (D) via the first large main surface (31). Furthermore, a reflector (5) is provided, which is arranged adjacent to the second main surface (32), wherein the reflector (5) has at least one light-transmissive region (51) configured in such a way that a further part of the light is emitted for generating the indirect lighting (I) via the second main surface (32) through the light-transmissive region (51).

Description

Luminaire for generating direct lighting and indirect lighting

The invention relates to a luminaire for generating a direct illumination and an indirect illumination, which has an LED light source and a light guide plate.

Such a lamp is known from DE 10 2008 014 317 AI. In this luminaire, the light guide plate is oriented horizontally, wherein the light of the LED light source is irradiated into the light guide plate via an edge side narrow side surface and further discharged via the downward facing main surface of the light guide plate. To generate the indirect lighting, the luminaire has second luminous means, which are arranged laterally next to the LED light source and the light guide plate. This is associated with corresponding expenditure or corresponding costs.

The invention has for its object to provide a corresponding improved luminaire. In particular, the light should allow for a low overall height a simple design and do not require a separate light source to produce the indirect lighting.

This object is achieved according to the invention with the object mentioned in the independent claim. Particular embodiments of the invention are set forth in the dependent claims.

According to the invention, there is provided a luminaire for producing a direct illumination and an indirect illumination, which has an LED light source for generating a light, and a light guide plate having a first main surface and a second main surface, the edge over a narrow side surface with the first Hauptoberfiäche is connected, wherein the LED light source is arranged such that the light is irradiated on the narrow side surface in the light guide plate and is further emitted to a part for generating the direct illumination on the first major Hauptoberfiäche. Furthermore, the lamp has a reflector, the is arranged adjacent to the second main surface. In this case, the reflector has at least one light-transmissive region which is designed in such a way that a further part of the light is emitted through the light-transmissive region for the purpose of producing the indirect illumination via the second main surface.

Due to the fact that the reflector has a transparent area, the light generated by the LED light source can advantageously be used both to generate the direct illumination and to generate the indirect illumination. In this way it is possible to dispense with a separate light source for generating the indirect lighting. By an appropriate choice of the size of the

In this case, the light-permeable area opens up the possibility of setting the proportion of light which serves to produce the indirect illumination to the light emitted by the luminaire in total as quasi as desired. This means that the luminaire can achieve a specific desired ratio of indirect lighting to direct lighting very precisely.

Preferably, the translucent area is formed by a passage opening of the reflector. This allows a manufacturing technology particularly simple and advantageous embodiment of the translucent area.

Preferably, the reflector is plate-shaped and plane parallel to the

Light guide plate arranged. With this configuration, the lamp can be designed with high efficiency with a very low height. Preferably, the light guide plate is on the second major surface

Structural elements for coupling the light over the first main surface. As a result, the decoupling of the light over the first main surface can be made particularly efficient and well adjusted. Further preferably, the structural elements within a surface area of the second main surface, which is delimited by a normal projection of the translucent area of the reflector, designed differently than in an immediate vicinity of this

Surface area. This can be achieved that over the first

Main surface emitted light is emitted particularly homogeneous. To this Way, in particular, that when looking at the first

Main surface no, caused by the translucent area dark spot or inhomogeneity is recognizable or at least significantly reduced. For this purpose, the structural elements within the surface area preferably have a greater density in terms of manufacturing technology than in the immediate surroundings.

Preferably, the structural elements within the surface area are designed such that the part of the light which is emitted via the first main surface to generate the direct illumination is emitted homogeneously within a normal projection of the surface area and the immediate surroundings. This is advantageous with respect to the external appearance of the lamp and with respect to a particularly homogeneous light output.

Preferably, the lamp has a plurality of pairs of an analogously designed transparent area of the reflector and a corresponding thereto

corresponding, analogously designed surface area of the first main surface. This makes it possible to achieve that the light is emitted uniformly over the second main surface in order to produce the indirect illumination.

Preferably, the structural elements are designed as a function of their distance from the LED light source, in particular denser with increasing distance. In this way it can be achieved that the light output over the entire first main surface viewed is particularly homogeneous, especially not with

increasing distance from the LED light source decreases in intensity.

Preferably, the structural elements are formed by engraving, in particular by means of a laser treatment. This is advantageous in terms of manufacturing technology and makes it possible to design the structural elements and thus their effect particularly precisely.

Preferably, the structural elements are formed by linear elements; This is manufacturing technology particularly easy to implement. Advantageously, the line-shaped elements have a width between 0.2 mm and 1, 5 mm, in particular between 0.6 mm and 1.0 mm, for example, 0.8 mm. These values have proven to be particularly suitable. Preferably, the translucent area has a diameter between 5 and 50 mm.

The lamp is particularly suitable if it is designed in the form of a pendant lamp or floor lamp.

Preferably, the luminaire is designed such that the ratio between the luminous flux, which is formed by the luminaire by the further part of the light for generating the indirect illumination and the total luminous flux, which is formed by the light emitted by the lamp as a whole, greater than 4%, preferably greater than 10%.

The invention is explained in more detail below with reference to an embodiment and with reference to the drawings. 1 shows a schematic diagram in the manner of a cross-section to the lighting technology

Structure of a lamp according to the invention,

2 is a perspective sketch of the components LED light source,

Light guide plate and reflector according to an embodiment, wherein the reflector is separated from the other two components,

3 shows a view of the first main surface of the light guide plate in a case without a special configuration of the structural elements in the region of the passage openings of the reflector,

Fig. 4 is a view of the first main surface of the light guide plate in a case with a special configuration of the structural elements in Area of the passage openings of the reflector,

Fig. 5 is a view of the first main surface of the light guide plate in a case where in two through holes the

Structural elements have no special configuration, in a third through hole, the structural elements have a high gravitational density, in a fourth through hole, the structural elements have a too low engraving density and at a fifth through hole, the structural elements have a particularly suitable gravure density, so that the location of this fifth through hole is practically undetectable when looking at the first main surface, and

6 shows an example of an embodiment of the structural elements in the region of a through-hole and its immediate surroundings.

Fig. 1 shows a schematic diagram in the manner of a cross section to the lighting structure of a lamp according to the invention for generating a direct lighting D and an indirect lighting /. The luminaire has an LED light source 2 for generating a light and a light guide plate 3. These two components 2, 3 may be arranged in a manner known per se, for example via a frame element. Other components, such as power supply means of the LED light source 2 are not shown in the figure for clarity. They may be provided as known per se from the prior art.

By virtue of the abovementioned structure, the luminaire may in particular be an overall surface-shaped luminaire. The lamp can have a particularly low height.

For example, the LED light source 2 may comprise an elongated board which is aligned with its longitudinal axis normal to the plane of the drawing with respect to the illustration of FIG. 1 and on which, in particular along a straight line, a plurality of LEDs are arranged which generate the light. The light guide plate 3 has a first main surface 31 and a second one

Hauptoberfiäche 32, wherein the second Hauptoberfiäche 32 is connected at the edge via a narrow side surface 33 with the first Hauptoberfiäche 31. In the present description, it is assumed that the lightguide plate 3 is oriented horizontally oriented so that the first main surface 31 faces downward and the second main surface 32 faces upward. This serves only the

Description and is not limiting in so far. However, the orientation mentioned is particularly suitable, for example, when the lamp is a pendant lamp; the direct lighting D takes place here in the lower

Half-space and the indirect lighting / upwards.

The LED light source 2 is arranged such that the light over the narrow

Side surface 33 is irradiated or coupled into the light guide plate 3. This is a structure in accordance with the so-called "sidelite

In the following, the light is then radiated to a part for producing the direct illumination D via the first large main surface 31, as schematically indicated in Fig. 2 by four exemplary light beams d1, d2, d3, d4 Irradiation is shown from one side, but it can generally be provided an irradiation of the light in the light guide plate 3 over several sides, so for example over two opposite sides.

Furthermore, the luminaire has a reflector 5, which is arranged adjacent to the second main surface 32. The reflector 5 is preferably designed highly reflective. As a result, any loss of luminous flux by absorption of light can be kept very low. The reflector 5 initially serves to direct a portion of the light emerging from the light guide plate 3 upwards, ie through the second main surface 32, back into the light guide plate 3.

In Fig. 2, the construction described in perspective in the manner of a

Exploded exploded view, wherein the reflector 5 is shown separated from the light guide plate 3. In the assembled state, the reflector 5 to the Light guide plate 3 arranged adjacent, as shown in Fig. 1. Preferably, the reflector 5 is plate-shaped and arranged plane-parallel to the light guide plate 3. The reflector 5 has at least one light-transmissive region 51, which is designed in such a way that a further part of the light is emitted through the light-transmissive region 51 to produce the indirect illumination / via the second main surface 32, as schematically illustrated in FIG of three other exemplary light beams il, i2, i3 indicated. The light-permeable region 51 is preferably a recess or passage opening of the reflector 5. In this way, the light-permeable region 51 can be produced particularly easily.

By designing a plurality of corresponding through-holes can be virtually arbitrarily set or regulate exactly what proportion of the light generated by the LED light source 2 to produce the indirect light / is to be used, because there is a proportional relationship between the size of

Through holes and the amount of indirect light. In particular, the number of passage openings can be selected accordingly and their shapes can be suitably determined. Preferably, the reflector 5 is perforated for this purpose, so for example provided with corresponding through holes at the same distance and the same size. It is thus in particular no separate light source for generating the indirect lighting required.

To decouple the light or the "part" of the light over the first

Hauptoberfiäche 31 for generating the direct lighting D, the light guide plate 3 preferably on its second Hauptoberfiäche 32 structural elements 4. By the structural elements 4 so light rays of light are deflected so that they can leave the light guide plate 3 in the course. This makes it possible to increase the efficiency of the light output downwards, as is already known per se from the prior art.

When the above-mentioned structural elements 4 are made to extend uniformly over the second main surface 32, the effect becomes the same achieved that those places where the through holes of the reflector 5 abut the light guide plate 3, when looking at the first main surface 31 of the light guide plate 3 by a reduced light output, so dark spots or

Dark spots are recognizable. The appearance of the luminaire in the "direct anteü" is thus changed. This is shown in FIG. 3, which by way of example shows a corresponding view of the first main surface 31 of the light guide plate 3 for this case. The dark areas arise because there the light is coupled upwards, that is, via the second main surface 32 of the light guide plate 3, and the reflector 5 has the passage openings there.

However, this effect is generally undesirable. Rather, it is usually desirable that the light guide plate 3 has a uniform brightness when viewed. In other words, usually the most homogeneous possible light output over the entire first main surface 31 is desired.

The formation of said dark spots can be counteracted by the structural elements 4-as shown by way of example in FIG. 6 -in a surface region 41 of the second main surface 32 that is projected by a normal (or vertical) projection of the light-transmissive region 51 of the reflector 5 is limited, designed differently than in an immediate environment 42 this

Surface area 41. In particular, this preferably have the

Structural elements 4 within the surface area 41 have a greater density than in the immediate vicinity 42. This makes it possible to increase the proportion of the downward light in the respective areas, while still allowing a partial release of the light upwards to produce the indirect illumination / takes place. The greater density of the structural elements 4 in the areas in question can be advantageously produced, for example, simply by additional engraving.

FIG. 4 shows a case in which the structural elements 4 have an increased density at the relevant points, here produced by an additional engraving. It can be seen that, in the case shown here, the locations of the passage openings are no longer recognizable as dark areas, but rather appear lighter than their surroundings. Therefore, it can be achieved by suitable design of the structural elements 4, that the points where the through holes are located, are practically no longer recognizable. This is illustrated with reference to FIG. 5. Here are first two places to recognize LI, where the location of the through holes

Dark spots can be recognized. At a further point L2, the engraving density is set too high so that this point L2 appears brighter than its surroundings. At an even further point L 3, the engraving density is set too low, so that this point L 3 appears darker than their surroundings. And at one point L4, the engraving density is optimally chosen, so to speak, so that this point L5 practically does not differ in its brightness from its surroundings, and thus is practically not recognizable.

Thus, two effects occur which ideally compensate each other: (i) decoupling into the indirect component through the open reflector 5 and (ii) amplified decoupling into the direct component through increased density of the engraving.

Accordingly, the structural elements 4 are preferably within the

Surface area 41 designed such that thereby the portion of the light that is emitted to generate the direct illumination D via the first main surface 31, is radiated homogeneously within a normal projection of the surface region 41 and the immediate environment 42.

The locations of the passage openings of the reflector 5 can be laminated in this manner, so to speak, and a particularly homogeneous light output can be achieved over the entire first main surface 31 of the light guide plate 3.

As in the example shown the case, the lamp preferably has a plurality of pairs of an analogously designed transparent area 51, 5 of the reflector 5 and a corresponding thereto, analogously designed

Surface area of the first main surface 31 on. As a result, the emission of light for generating the indirect illumination / is particularly suitable Taxes. Preferably, the passage openings of the reflector 5, as already mentioned above, formed by a perforation of the reflector 5.

Further preferably, the structural elements 4 are designed as a function of their distance from the LED light source 2, in particular are made denser with increasing distance. This makes it possible to achieve that the light emission via the first main surface 31 is independent of the distance from the LED light source 2, as is known as such from the prior art. As already mentioned, the structural elements 4 can be formed particularly advantageously by engraving, in particular by means of a laser treatment. For example, the structural elements 4 may be formed by line-shaped elements, wherein the line-shaped elements preferably have a width between 0.2 mm and 1.5 mm, in particular between 0.6 mm and 1.0 mm, for example 0.8 mm. These particular values have been found to be particularly suitable in practice with respect to the effects described herein. The structural elements 4 can thus be, for example, a grid or a grid structure. The grid may be a square grid; more generally i can do it at the

Structural elements 4, however, for example, also lines, triangular lattice, area engravings, etc. act.

The translucent region 51 or the through-opening may, for example, have a diameter between 5 and 50 mm. There are several size parameters that influence each other. The bigger the

Through opening of the reflector 5, the denser the structural elements 4 or the grid must be selected for lamination. The width of the grid lines also affects the efficiency of the lamination. The above values have been found to be particularly suitable in this regard.

As mentioned above, the lamp may be, for example, a pendant lamp. However, it may also be, for example, a floor lamp. Preferably, the luminaire is designed in such a way that the ratio between the luminous flux which is formed by the luminaire by the further part of the light for producing the indirect illumination / and the total luminous flux which is formed by the light emitted by the luminaire as a whole is greater than 10% is. This corresponds to a classic definition of a luminaire for the generation of direct lighting and indirect lighting. But it is also possible that the indirect proportion is lower, about 4% to 5% to achieve lighting effects such. B. a corona effect.

The luminaire according to the invention allows a design with a low overall height in a comparatively simple design. To achieve the indirect lighting while no separate light source is required.

Claims

claims

Luminaire for generating a direct lighting (D) and an indirect lighting (I), comprising

- An LED light source (2) for generating a light and

- A light guide plate (3) having a first main surface (31) and a second Hauptoberfiäche (32) which is peripherally connected via a narrow side surface (33) with the first Hauptoberfiäche (31),

wherein the LED light source (2) is arranged such that the light is irradiated into the light guide plate (3) via the narrow side surface (33), and further to a direct illumination generating part (D) via the first large main surface (31 ), as well as

a reflector (5), which is arranged adjacent to the second main surface (32),

characterized,

in that the reflector (5) has at least one translucent area (51) designed in such a way that a further part of the light for generating the indirect illumination (I) passes through the translucent area (51) via the second main surface (32) is delivered.

Luminaire according to claim 1,

in that the translucent area (51) is formed by a passage opening in the reflector (5).

Luminaire according to claim 1 or 2,

in which the reflector (5) is plate-shaped and plane-parallel to the

Light guide plate (3) is arranged.

Luminaire according to one of the preceding claims,

in which the light guide plate (3) is on the second main surface (32)

Structural elements (4) for coupling the light over the first main surface (31).

Luminaire according to claim 4,

in which the structural elements (4) are designed differently within a surface region (41) of the second main surface (32) which is delimited by a normal projection of the light-permeable region (51) of the reflector (5) than in an immediate environment (42 ) this

Surface area (41).

Luminaire according to claim 5,

in which the structural elements (4) have a greater density within the surface area (41) than in the immediate vicinity (42).

Luminaire according to one of claims 4 to 6,

in which the structural elements (4) are designed within the surface area (41) in such a way that, within a normal projection of the surface area (41), the part of the light which is emitted to produce the direct illumination (D) via the first main surface (31) ) and the immediate environment (42) is homogeneously radiated.

Luminaire according to claim 7,

The plurality of pairs each having an analogous designed translucent area (51, 5) of the reflector (5) and a corresponding thereto correspondingly designed analogous Oberfiächenbereich (41, 41 ') of the first main surface (31).

Luminaire according to one of claims 4 to 8,

in which the structural elements (4) are designed as a function of their distance from the LED light source (2), in particular are made more dense with increasing distance.

10. Luminaire according to one of claims 4 to 9,

in which the structural elements (4) are formed by engraving, in particular by means of a laser treatment.

Luminaire according to one of claims 4 to 10,

in which the structural elements (4) are formed by linear elements, the linear elements preferably having a width between 0.2 mm and 1.5 mm, in particular between 0.6 mm and 1.0 mm,

for example, 0.8 mm.

Luminaire according to one of the preceding claims,

wherein the translucent region (51) has a diameter between 5 and 50 mm.

Luminaire according to one of the preceding claims

in the form of a pendant or floor lamp.

Luminaire according to one of the preceding claims,

which is designed such that the ratio between the luminous flux which is formed by the luminaire by the further part of the light for generating the indirect illumination (I) and the total luminous flux, which is formed by the light emitted by the light in total, larger than 4%,

preferably greater than 10%.