ES2361392T3 - LED LIGHT MODULE WITH REFLECTOR. - Google Patents

Abstract

Luminous module, with a bottom element (1), which has a bottom (3) that reflects the light and two side walls (4, 5) opposite each other protruding from the bottom (3), a cover plate (2) which can be fixed on the bottom element (1) that is translucent and diffuses the incident light diffusely, the space being delimited by the bottom (3), the side walls (4, 5) and the cover plate ( 2) full of air, and LED (10), characterized in that on each of the two side walls (4, 5) a slat (8) is fixed which is inclined with respect to the side wall (4, 5) with a predetermined angle (α), because the LEDs (10) are applied on the bottom-facing side (3) of the ribbon (8) and illuminate the bottom (3), the background reflection properties (3) being in the center area between the two side walls (4, 5) different from in proximity to the two side walls (4, 5).

Description

The invention relates to a light module of the type mentioned in the preamble of claim 1.

Such luminous modules exist in many embodiments, on the one hand as modules whose dimensions correspond to a predefined norm and which are assembled to form a ceiling or wall that in turn serves as a means of illumination. On the other hand there are also modules with special masses for specific use purposes, for example, as lighting means in a kitchen. Moreover, such modules are used as light boxes for labeling, signage as well as advertising purposes and as indication panels. Conventional light modules contain most of the time fluorescent lamps whose disadvantages are high current consumption and limited life.

From JP 2005031596 an indication element is known for the indication of a graphic element according to the preamble of claim 1. The indication element contains a bottom, side walls and a translucent cover plate as well as a plurality of LED They are placed on a side wall. The background is provided with white reflection plates. The cover plate is composed of a diffusely dispersing plate and a film translucent with the graphic element.

The invention is based on the objective of developing a light module that has a lower current consumption and that during the whole useful life has practically no maintenance costs.

The mentioned objective is solved according to the invention by means of the features of claim 1.

The light module according to the invention contains commercially available light diodes which are generally known as LEDs (light emitting diodes). Its current consumption amounts to the fraction of the current consumption of a fluorescent lamp, bulb or halogen lamp with the same light output. The light module comprises a bottom element and a cover plate that can be detachably attached to the bottom element. The cover plate is translucent but not transparent. Scatter the incident light diffusely. The bottom element has a bottom and two side walls protruding from the bottom, opposite each other. On each of the two side walls a slat is fixed that is inclined at a predetermined angle with respect to the side wall. On the side facing the bottom of the ribbon are LEDs that illuminate towards the bottom. The background is set to reflect light. The reflection properties of the background are modified towards the two side walls to compensate for the light radiation of the LEDs that decreases towards the center, to be reflected by the background. In the space that is limited by the bottom element and the cover plate is air. No waveguide and / or fiber optic are needed. This space and, therefore, the entire light module, therefore, are free of light conductive components.

The bottom can be divided into a plurality of first and second partial surfaces. The surface occupied by the first partial surfaces increases in a certain region compared to the surface occupied by the second partial surfaces with increasing distance from the side wall to the center between the side walls. In a preferred embodiment, the first partial surfaces are differentiated from the second partial surfaces in the reflection characteristic: the first partial surfaces disperse the light in a non-diffuse way, on the contrary, the second partial surfaces disperse the light in comparison with this so diffuse. The first partial surfaces are, for example, high gloss aluminum and have a reflective surface, while the second partial surfaces are provided with a matt white surface. In an alternative embodiment, the first partial surfaces are differentiated from the second partial surfaces in the reflection capacity, the reflection capacity R1 of the first partial surfaces being greater than the reflection capacity R2 of the second partial surfaces.

The invention is explained in more detail below by means of embodiments and by drawing. The figures are not drawn to scale.

Figure 1 shows in a top view a background element of a light module, Figure 2 shows the background element with cover plate applied to the light module in a

section along line I-I of Figure 1, Figures 3, 5 illustrate possibilities of locally modifying the reflection capacity of the bottom of the

background element by means of a structured reflection layer and Figure 4 shows details of the invention by means of a cutout of Figure 3.

The light module according to the invention comprises a bottom element and a cover plate that can be detachably attached to the bottom element. Figure 1 shows the background element 1 in a top view. Figure 2 shows the bottom element 1 with the cover plate 2 in a section along the line II of Figure 1. The bottom element 1 is composed of a bottom 3 and at least two side walls 4 and 5 opposite each other, protruding from the bottom 3. In many applications, the bottom element 1, however, contains four side walls 4 to 7 that form a peripheral wall. On the first side wall 4 and on the second opposite side wall 5 a strip 8 is fixed. The strip 8 is inclined with respect to the side wall 4 or 5 at a predetermined angle . On the bottom-facing side 3 of the strip 8, strips 9 with LEDs 10 (LED) are fixed. Such strips 9 are available in the market in many embodiments. The strips 9 contain, for example, LED 10 arranged in a row that all radiate white light or LED 10 in accordance with the RGB standard, of which alternately each third emits red light, green light or blue light. A control device controls the LEDs 10. When red, green and blue LEDs 10 are present, then the control device can control the LEDs 10 so that the light module is illuminated in any color. The space delimited by the bottom 3, the side walls 4, 5 and possibly 6, 7 and the cover plate is full of air, however, this space is not waterproofed air tight with respect to the environment. No light conductive elements such as waveguide and fiber optics are needed.

The LEDs 10 illuminate the background 3, which is configured so that it reflects light and serves as a reflector. The light radiated by the LEDs 10 at the bottom, therefore, is reflected at the bottom 3 and reaches the outside through the cover plate 2. The cover plate 2 is translucent but not transparent. Its objective is to diffuse the incident light diffusely to all sides. The cover plate 2, for example, is a milky way plexiglass plate milky. The angle  is selected in such a way that the light cones 11 of the LEDs 10 partially overlap in the zone 12 of the center of the bottom 3. The backlight 3 by the LEDs 10 is not uniform because the intensity of the light irradiated by the LEDs 10 decreases with increasing separation of the side wall 4 or 5. The reflection properties of the bottom 3, therefore, are modified from the center between the side walls 4 and 5 to the side wall 4 and 5 so that the Cover plate 2 appears evenly clear to the human eye. In order to achieve the highest possible brightness of the light module with a predefined power of the LEDs 10, the reflection capacity of the background 3 is advantageously maximum at least in the center. In Figure 2, the equally long arrows 13 illustrate the uniformity of the light irradiation of the light radiated by the cover plate 2.

The bottom 3 of the bottom element 1 advantageously has a surface as white as possible and as matt as possible that disperses the incident light in the most diffuse way possible and on which a structured reflection layer is applied on the surface that is composed, by example, high gloss aluminum. The bottom 3, therefore, is divided into at least a first partial surface of high gloss aluminum and second partial surfaces with a matt white surface. The color of the white surface is, for example, the "traffic white 9016" known as the whiter white. The matte surface diffusely reflects the incident light. The white color causes a very large part of the incident light to disperse back and only a very small part of the incident light is absorbed. The reflection layer, however, does not diffuse the incident light (compared to this). Since both the first and second partial surfaces have a high reflection capacity, a high light efficiency is obtained. The division of the bottom surface 3 into first and second partial surfaces with different reflection characteristics, namely diffuse reflection and non-diffuse reflection, causes the edge of the covering plate 2 to appear as clear as the central parts of the cover plate 2.

Another solution consists in dividing the bottom 3 into first and second partial surfaces that differ in the reflection capacity, the reflection capacity R1 of the first partial surfaces being greater than the reflection capacity R2 of the second partial surfaces. The bottom element 1 may be made, for example, of metal, whose surface is varnished with oven-dried, or of plastic. The reflection capacity of such a surface is relatively low, that is, the surface acts as an absorption layer that absorbs a large part of the incident light. On the bottom 3 a structured reflection layer is applied on the surface in such a way that the reflection capacity of the bottom 3 increases starting from the side walls 4 and 5 towards the center between the side walls 4 and 5. The reflection layer can be, for example, a reflective sheet or a metal layer applied by vaporization or simply a white surface.

Below are different examples of how the reflection layer can be structured in the solutions described above.

Example 1

Figure 3 shows the bottom 3 and the side walls 4 to 7 in a top view. The drawing is not drawn to scale. The bottom 3 is divided into two regions: a first joined region 14 and a second region 15 complementary to the first region 14 (region 15 is composed of two separate sub-regions found in Figure 3 to the left and right of the first region 14). The first region 14 of the bottom 3 is covered with a reflection layer 16. The edge 17 of the first region 14 is configured on the side facing the side wall 4 and the side wall 5 in the form of saw teeth.

Figure 4 shows the area C bordered in Figure 3 by a dashed line to explain details of the invention. (The first side wall 4 is only shown to illustrate the location of the zone C with respect to the first side wall 4). The entire bottom 3 of the bottom element 1 by definition can be divided into first partial surfaces 19 with first reflection properties and second partial surfaces 20 with second reflection properties. As can be seen simply in Figure 4, the surface occupied by the first partial surfaces 19 increases in comparison with the surface occupied by the second partial surfaces 20 in the area of the sawtooth with increasing distance from the side wall 4 .

A practical test for a luminous module that presented a size of 60 cm * 60 cm correspondingly with a widely generalized norm has shown that the tips of the sawtooth do not have to reach the center at all (represented by line 18) between the two side walls 4 and 5, but relatively short tips with a length B of 5 to 10 cm are sufficient.

The shape of the edge 17 between the two regions 14 and 15 is not limited to the shape of the sawtooth. The edge 17, for example, can also be sinusoidal, wavy, etc. or it can be delimited by curves with exponential development.

When the first partial surfaces 19 are configured in such a way that they reflect in a non-diffuse way the incident light and the second partial surfaces 20 in such a way that they diffusely reflect the incident light, this means that the light radiated by the LEDs 10 that affects on the first region 14 it is reflected as in a mirror and that the light radiated by the LEDs 10 that affects the second region 15 is dispersed very widely. Therefore, in the area of the sawtooth the reflection characteristic of the bottom 3 is modified.

Example 2

In this example depicted in Figure 5, the reflection layer 16 forms an unbound region, but is composed of a plurality of first partial surfaces 19 and second partial surfaces 20. The density of the first partial surfaces 19 increases from the walls lateral 4 and 5 towards the center. The first partial surfaces 19 are, for example, as shown, points. Points can be distributed evenly or randomly. The size of the points is of minor importance, it can vary from a few micrometers to a few millimeters or even centimeters. This example is particularly suitable when the reflection layer 16 is produced by metal vaporization or by injection application of a reflective material otherwise, for example, in the screen printing process. Also in this example, therefore, the area occupied by the first partial surfaces 19 is increased compared to the area occupied by the second partial surfaces 20 with increasing distance from the side wall 4. A zone 12 that is in the center between the Two side walls 4 and 5 are completely covered with the reflection layer 16, since it is that the light module illuminates as clearly as possible with a predefined power of the LEDs 10.

In order to achieve uniform brightness of the light module, it is often necessary to provide other measures to prevent the LEDs 10 from lighting the other side walls 6 and 7. This, in fact, could lead to lighter unwanted areas on the cover plate 2. To To avoid this there are two possibilities:

1. The two outermost LEDs 10 of a strip 8 are arranged with a predetermined minimum A separation (Figure 1) with respect to the adjacent side wall 6 or 7 in such a way that it does not impinge or practically does not impact light radiated directly by the LED 10 on the side walls 6 and 7. In the case of the example shown in Figure 1, this on one of the slats 8 are LEDs 10.1.1 and 10.1, n, on the other slat 8, LEDs 10.2.1 and 10.2, n. 2nd. The side walls 6 and 7 are made of a material or are coated on the side facing the bottom 3 with a material that has a high absorption capacity for light or a small reflection capacity for light. The light absorption capacity is so great that the cover plate 2 appears uniformly for the luminous human eye. 2b The side walls 6 and 7 as an alternative can also be made with a very white and matt surface so that they reflect the incident light in a diffuse way, that is, they disperse it as widely as possible.

The possibilities that have been mentioned can also be combined. They cause alone or in combination that the cover plate 2 illuminates uniformly clearly and, therefore, does not have lighter areas.

The luminous module according to the invention guarantees a uniform distribution of the luminosity over the entire translucent covering plate 2 that diffuses diffusely.

It is also possible that several luminous modules have a common cover plate 2.

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is solely for the convenience of the reader. This list is not part of the European patent document. Although great care has been taken in the collection of references, errors or omissions cannot be excluded and the EPO disclaims all responsibility in this regard.

Patent documents cited in the description JP 2005031596 B [0003]

Claims (8)

one.

 Luminous module, with a bottom element (1), which has a bottom (3) that reflects the light and two side walls (4, 5) opposite each other protruding from the bottom (3), a cover plate (2) which can be fixed on the bottom element (1) that is translucent and diffuses the incident light diffusely, the space being delimited by the bottom (3), the side walls (4, 5) and the cover plate ( 2) full of air, and LED (10), characterized in that on each of the two side walls (4, 5) a slat (8) is fixed which is inclined with respect to the side wall (4, 5) with a predetermined angle (), because the LEDs (10) are applied on the bottom-facing side (3) of the ribbon (8) and illuminate the bottom (3), the background reflection properties (3) being in the center area between the two side walls (4, 5) different from in proximity to the two side walls (4, 5).

2.

 Luminous module according to claim 1, characterized in that the bottom (3) can be divided into first partial surfaces (19) and second partial surfaces (20), which have different reflection properties and because the surface occupied by the first partial surfaces (19) in comparison with the surface occupied by the second partial surfaces (20) in a region between the first side wall (4) and the center between the two side walls (4, 5) and a region located between the Second side wall (5) and the center between the two side walls (4, 5) increases with increasing distance from the corresponding side wall (4, 5).

3.

 Luminous module according to claim 2, characterized in that the first partial surfaces

(19) non-diffusely reflect the incident light and because the second partial surfaces (20) diffusely reflect the incident light. 4. Luminous module according to claim 3, characterized in that the first partial surfaces (19) have a reflective surface and the second partial surfaces (20), a matt, white surface. 5. Luminous module according to claim 2, characterized in that the first partial surfaces (19) have a reflection capacity R1 and the second partial surfaces (20), a reflection capacity R2, the reflection capacity R1 being greater than the reflection capacity R2.

6.

 Light module according to one of claims 1 to 5, characterized in that the light module has two additional side walls (6, 7) and that the two outermost LEDs (10) of a strip (8) are arranged with a minimum separation (A) predetermined with respect to the other side walls (6, 7).

7.

 Luminous module according to one of claims 1 to 5, characterized in that the luminous module has two additional side walls (6, 7), whose light absorption capacity on the bottom-facing side (3) is so large that The cover plate (2) appears uniformly for the luminous human eye.

8.

 Luminous module according to one of claims 1 to 5, characterized in that the luminous module has two additional side walls (6, 7), whose side oriented towards the bottom (3) has a matt white surface.