WO2008058575A1

WO2008058575A1 - Modular surface lighting system

Info

Publication number: WO2008058575A1
Application number: PCT/EP2006/068626
Authority: WO
Inventors: Udo Custodis
Original assignee: Osram Gesellschaft mit beschränkter Haftung
Priority date: 2006-11-17
Filing date: 2006-11-17
Publication date: 2008-05-22

Abstract

The invention relates to a lighting system with light elements (1, 20, 40) supplied from one side. These lighting elements form a common light emission surface and have adjacent edge sections (12, 26,...) which overlap each other in such a way that a region (26) which is optically darker in relation to the continuous light emission surface of the one lighting element (20) can be brightened by means of an overlapping edge section (12) of the other lighting element (1). In an inventive light element (1) that can be supplied from one side, the invention provides two opposite lying edge sections (6, 12), one of which can be supplied using a light source (16) from one side, and the other approaches the light emission surface essentially at an acute angle.

Description

description

MODULAR SURFACE LIGHTING SYSTEM

Technical area

The invention relates to a lighting system and a one-sided feedable lighting element for such a lighting system.

State of the art

Large background illuminations, which are used in particular in liquid crystal screens, are known from the prior art.

In such backlighting, two types are distinguished according to the type of light coupling:

According to a first type, the light source is located on the side of the backlight opposite the light emission surface and often completely occupies this side. If fluorescent tubes are used as the light source for such backlighting, the resulting waste heat leads to a reduction in the service life of the fluorescent tubes of the backlighting. As a remedy, it has been proposed in German Utility Model 202005015061 U1 to use light emitting diodes for this type of backlight. In this case, a plurality of light-emitting diodes radiating in all directions is provided on the side of the backlighting which is opposite to the light-emitting surface. Although the depth of the backlight can be reduced compared to fluorescent tubes, it is due to the need for a light guide plate in the backlight and due to the arrangement the light emitting diodes behind this the installation depth large, despite the reduction in comparison to the depth when using fluorescent tubes.

As an alternative to this backlight with vertical light coupling, a backlight with side light coupling (edgelight system) can be used in the second type of light coupling. This is shown for example in US publication 20060104090 Al. Here, the respective light from strip-shaped light sources are coupled from the edges of the light panel. Although light strips are provided on all four edges of the light panel in this document mentioned. For larger dimensions of the light panel, however, a visible decrease in intensity in the light from the edge towards the center is observed. Thus, no uniform light intensity over the entire light emitting surface can be ensured.

When a plurality of such light panels are used side by side, arise in the area in which adjacent lighting panels next to each other, dark edges, so that in backlighting with lateral light coupling a one-piece design of the light panel is preferred.

Presentation of the invention

The invention is based on the object to provide a luminous system in which a uniform illumination of large areas with low installation depth is possible.

This object is achieved by the features of claims 1 and 9. A luminous system according to the invention has at least two lighting elements, each fed on one side, which form a common light-switching surface. The one-sided fed edge portion of a luminous element can be covered with an edge portion of the other luminous element in such a way that a respect to the continuous Lichtabstrahlfläche optically dark area of the one-sided fed edge portion of a luminous element by the edge portion of the other luminous element is illuminated. In this way, a modular composite lighting system can be implemented with a variety of lighting elements.

It is preferred that a respective luminous element can be fed on one side by an associated light source, wherein the light source irradiates the edge section fed on one side substantially at right angles to the light radiating surface of the respective luminous element at this edge section. As a result, more than two lighting elements can be connected to one another and ensure uniform illumination of this multiplicity of lighting elements.

The respective light source irradiates the associated luminous element in a preferred embodiment of a side which is opposite to the light emitting surface. As a result, light shadows are avoided by the light source.

Furthermore, it is preferred that one of the edge sections of the luminous elements has an obtuse or an acute angle with respect to the continuous light-emitting surface. As a result, lighting elements can be implemented, whose edge portions are brought into abutment to form a continuous Lichtabstrahlfläche.

The lighting system is preferably a system for backlighting, for example, translucent fabrics or liquid crystal displays. Thus, using one type of light emitting element, the backlighting can be implemented for a variety of liquid crystal displays with different screen diagonals.

It is preferred that the lighting element made of synthetic glass, such as. As acrylic glass, or glass is made. This allows a high transparency, a high transparency and a high scratch resistance, which is particularly advantageous in the manufacturing process implement.

In a further embodiment, the lighting elements are formed like a strip. Thus, for example, backlights for liquid crystal displays having an aspect ratio of 4: 3 and backlights for liquid crystal displays having an aspect ratio of 16: 9 can be realized with the same luminous elements. Due to the strip-like configuration, the light elements can also be used in high-resolution screens and with large screen diagonals.

It is preferable that the light source is a light emitting diode. This allows a small distance between the light emitting element and the light source and thus a small overall depth. Furthermore, a light-emitting element that can be fed on one side is provided, which has a light-emitting surface and two opposing edge sections. One of the edge sections can be fed by one light source on one side and the other of the edge sections runs at an acute angle to the light emission surface. As a result, a uniform illumination can be ensured with the entire light emission surface.

It is preferred if the luminous element can be irradiated by the light source substantially at right angles to the light emitting surface of the luminous element. As a result, a multiplicity of luminous elements can be provided in juxtaposition with uniform illumination.

Particularly advantageous embodiments of the invention are described in the dependent claims.

Brief description of the drawings

The invention will be explained in more detail with reference to a preferred embodiment. Show it:

1 is a sectional view of a light emitting element according to the invention with light source,

Fig. 2 shows two light elements, between which a dark edge is formed, and

Fig. 3 is a lighting system with three lighting elements according to the present invention. Preferred embodiment of the invention

Fig. 1 shows a cross-sectional view of a luminous element 1 according to the invention, which has in cross-section substantially the shape of a parallelogram.

The light-emitting element 1 has a light-emitting surface 2 and a reflection surface 4 lying opposite to the light-emitting surface. At an acute angle α to the reflection surface 4, a light entrance edge surface 6, which is located at a light entry edge section 8 of the luminous element 1, extends. Opposite the light entry edge section 8, a light exit edge section 10 with a light exit edge surface 12 is provided on the light element 1. The light exit edge surface 12 forms an acute angle β with the light emission surface 2, which preferably corresponds essentially to the acute angle α of the light entry edge surface 6.

The luminous element is preferably produced using synthetic glass, for example acrylic glass such as polymethyl acrylate (PMMA) or glass.

The reflection surface 4 is preferably formed in such a manner that at this a total reflection of the light which is radiated from the light entry edge portion 8 to the light exit edge portion 10 occurs. The light entrance edge surface 6 is associated with a light source 16 which preferably irradiates the light entrance edge surface 6 evenly.

The light source is preferably a light emitting diode (LED). Due to the use of LEDs, the distance between the light-emitting element 1 and the light source 16 are made small. Furthermore, LEDs emit no UV radiation, so that the radiation can be coupled directly into the light-emitting element. As LEDs, groups of red, green and blue LEDs, any combinations of these LEDs with one color or LEDs with two colors or a plurality of white LEDs can be used.

The light emitted from the light source 16 strikes the light entrance edge surface 6 in the light entrance edge portion 8, is reflected by the light entrance edge surface 6 and emerges from the light emitting surface 2 of the light element 1 after reflection at the reflection surface 4. In this case, a reflection also takes place at the light exit edge surface 12 of the light exit edge section 10, so that over a longitudinal dimension L in Fig. 1, between the intersection of the light entrance edge surface 6 and the light emitting surface 2 and the intersection between the Lichtabstrahlflä - Che 2 and the light exit edge surface 12 extends, a Lichtabstrählung by the light-emitting element 1 takes place.

The light-emitting element 1 is fed by the light source 16 only on one side. Due to the advantageous properties of LEDs, the distance between the light source 16 and the luminous element 1 can be made small when using these as a light source, so that a small thickness of a luminous system with luminous element 1 and light source 16 can be obtained.

Hereinafter, the function of the light exit edge surface 12 will be explained with reference to FIG. FIG. 2 shows a luminous element 100 with a light source 116. A light entry edge section 108 is provided in the same way as in the luminous element 1 according to FIG. In contrast to the embodiment according to FIG. 1, in the embodiment according to FIG. 2, the light exit edge surface 112 is not provided at an acute angle to the light emitting surface 2, but at a right angle to it.

If now a second light-emitting element 120 with the same structure as the light-emitting element 100 is provided in such a manner next to the light-emitting element 100 that the reflection surfaces lie in one plane, then the light-entrance edge surface 126 of the second light-emitting element 120 and the light exit edge surface 112 of the luminous element 100, there is a gap leading to a dark edge.

When a lighting system having such luminous elements 100, 120 is used, for example, as a backlight of liquid crystal displays, the dark edge 127 of FIG. 2 leads to a non-backlit portion of the liquid crystal display. This disadvantage is eliminated by an acute-angled design of the light exit edge surface 12 of FIG.

For the sake of illustration, reference is made to a lighting system with three luminous elements 1, 20, 40 from FIG. 3.

The lighting elements 20 and 40 correspond to the lighting element 1 and are arranged in relation to each other in such a way that the light exit edge surface 12 of the first lighting element 1 is in contact with the light entry edge surface 26 at the light entry edge section 28 of the second lighting element 20 , The light- Outlet edge surface 32 of the second light-emitting element 20 is in contact with the light-entry edge surface 46 of the third light-emitting element 40. Both the light entry edge surface 6 of the first light-emitting element 1 and the light exit edge surface 52 of the third light-emitting element 40 are each truncated to support the lighting system of FIG. 3. The result is a lighting system with a continuous Lichtabstrahlflache and a continuous reflection surface. Each of the luminous elements 1, 20, 40 is fed by an associated light source 16, 36, 56 on one side.

Due to the overlapping of the edge surfaces 12, 26 and edge surfaces 32, 46, no edge comparable to the dark edge 127 of FIG. 2 is obtained on the luminous elements in FIG. 3. More specifically, the area of the light emission surface above the light entrance surface 26 of the second light element is illuminated by light from the light source 16 and the area of the light emission surface above the light entrance edge surface 46 of the third light element is obtained by light from the light source 36.

In this way, it is possible to implement a modularly expandable lighting system, with which backlighting of liquid crystal displays of very different formats can be implemented using the same types of lighting elements, but in different numbers. As a result, liquid crystal screens with a high diagonal image can be modularly constructed. Due to the small depth of the lighting elements with light source, flat backlighting can be implemented. In contrast to backlighting with vertical light coupling According to the prior art, the depth does not increase with increasing screen size.

The present invention is not limited to that the angle α of the light entrance edge surface 6 of FIG. 1 is made substantially equal to the angle β of the light exit edge surface 12 of FIG. In an alternative embodiment, the angles α and β are designed differently from each other. In such a case, however, care must be taken that the angle β and the angle α of adjacent edge surfaces in a composite lighting system are made substantially equal in size, so that a uniform illumination is ensured.

Furthermore, the present invention is not limited to a planar configuration of the light entry edge surface 6 and the light exit edge surface 12. These surfaces can for example also be curved or provided with irregular contour. It is preferred that the contours of adjacent edge surfaces have a complementary shape when the luminaire system is assembled.

A luminous system with luminous elements fed on one side is described. These light-emitting elements form a common light-emitting surface and have adjacent edge portions which overlap in such a way that an optically darker region can be illuminated with respect to the continuous light-emitting surface of the one light-emitting element through an overlapping edge portion of the other light-emitting element. In a luminous element which can be fed on one side according to the invention, two opposing edge sections are provided, from one of which can be fed by one light source on one side and the other to the light emitting surface substantially acute angle tapers.

Claims

claims

1. lighting system with at least two, each one-side powered lighting elements (1, 20, 40) forming a common light emitting surface (2), wherein the one-sided fed edge portion (28) of a luminous element (20) having an edge portion (10) of the other Luminous element (1) in such a way ü- berdeckbar is that a with respect to the continuous Lichtabstrahlfläche (2) optically dark area of the one-sided fed edge portion (28) of a luminous element (20) through the edge portion (10) of the other luminous element (1) can be illuminated.

2. Lighting system according to claim 1, wherein a respective lighting element (1, 20, 40) by a respective light source (16, 36, 56) can be fed unilaterally, the one-sided fed edge portion substantially perpendicular to the light emitting surface (2) of the respective lighting element irradiated this edge section.

3. Lighting system according to claim 1 or 2, wherein the respective light source (16, 36, 56) irradiates the associated luminous element from a side (4) which is opposite to the light emitting surface (2).

4. Lighting system according to one of the preceding claims, wherein one of the edge portions (8, 10) of the lighting elements with respect to the continuous Lichtabstrahl- surface (2) has an obtuse or an acute angle.

5. Lighting system according to one of the preceding claims, wherein the lighting system is a system for background illumination of, for example, translucent materials or LCDs.

6. Lighting system according to one of the preceding claims, wherein the luminous element (1, 20, 40) made of art glass, such. Acrylic glass, or glass is made.

7. Lighting system according to one of the preceding claims, wherein the lighting elements (1, 20, 40) are strip-shaped.

8. Lighting system according to one of the preceding claims, wherein the light source (1, 20, 40) is an LED.

9. One-side lightable lighting element (1) having a light emitting surface (2) and two opposite edge portions (8, 10), of which the one

(8) by a light source (16) can be fed unilaterally, and of which the other (10) to the light emitting surface (2) tapers substantially at an acute angle.

10. One-side lightable lighting element, wherein by the light source (16) the lighting element (1) is substantially perpendicular to the light emitting surface (2) of the light-emitting element can be irradiated.