Sound absorbing lighting panel and modular surface system

Abstract

Disclosed is a sound absorbing lighting panel (100) comprising a sound absorbing member (120); an optical medium (130) over said sound absorbing member; a first set (140) of solid state lighting elements (142) arranged along a first edge of said optical medium; a translucent sheet (150) over the optical medium, said translucent sheet having a non-uniform degree of translucency such as a higher degree of translucency over a central region of said optical medium than over a first region of said optical medium comprising said first edge. A modular surface system including such a sound absorbing lighting panel is also disclosed.

Claims

1. A sound absorbing lighting panel comprising: a sound absorbing member; an optical medium over the sound absorbing member; a first set of solid state lighting elements arranged along a first edge of the optical medium; and a translucent sheet over the optical medium, the translucent sheet comprising a glass fiber mat coated with an opaque paint, wherein the opaque paint coating has a larger thickness over a first region of the optical medium comprising the first edge than over a central region of the optical medium so that the translucent sheet has a higher degree of translucency over the central region than over the first region.

2. The sound absorbing lighting panel of claim 1, wherein the first set of solid state lighting elements comprises a strip of light emitting diodes.

3. The sound absorbing lighting panel of claim 2, further comprising a second set of solid state lighting elements arranged along a second edge opposite the first edge of the optical medium, wherein the translucent sheet has a higher degree of translucency over the central region than over a second region of the optical medium comprising the second edge.

4. The sound absorbing lighting panel of claim 3, wherein the second set of solid state lighting elements comprises a further strip of light emitting diodes.

5. The sound absorbing lighting panel of claim 1, wherein the translucent sheet comprises a plurality of openings covering at least 3 % of its total surface.

6. The sound absorbing lighting panel of claim 1, further comprising a housing containing the sound absorbing member, the optical medium, the solid state lighting elements and the translucent sheet, the housing having reflective inner surfaces.

7. The sound absorbing lighting panel of claim 1, wherein the panel has a tile shape.

8. The sound absorbing lighting panel of claim 1, wherein the translucent sheet has a translucency gradient that is increasing from an edge portion of the sound absorbing lighting panel to the center of the sound absorbing lighting panel.

9. The sound absorbing lighting panel of claim 1, wherein the optical medium comprises an air-filled cavity.

10. A modular surface system comprising a plurality of panels mounted in a support frame, wherein at least one of said panels is a sound absorbing lighting panel according to claim 1.

11. The modular surface system of claim 10, wherein the surface system is a suspended ceiling system.

Description

BRIEF DESCRIPTION OF THE EMBODIMENTS

(1) Embodiments of the invention are described in more detail and by way of non-limiting examples with reference to the accompanying drawings, wherein:

(2) FIG. 1 schematically depicts an aspect of sound absorbing lighting panel according to an embodiment of the present invention;

(3) FIG. 2 schematically depicts another aspect of sound absorbing lighting panel according to an embodiment of the present invention;

(4) FIG. 3 schematically depicts the concept of the sound absorbing lighting panel of the present invention;

(5) FIG. 4 schematically depicts an aspect of sound absorbing lighting panel according to another embodiment of the present invention;

(6) FIG. 5 schematically depicts an aspect of sound absorbing lighting panel according to yet another embodiment of the present invention; and

(7) FIG. 6 schematically depicts a modular surface system according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

(8) It should be understood that the figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the figures to indicate the same or similar parts.

(9) FIG. 1 schematically depicts a bottom view of a sound absorbing lighting panel 100 according to an embodiment of the present invention, whereas FIG. 2 schematically depicts a cross-section of the sound absorbing lighting panel 100. The sound absorbing lighting panel 100 comprises a housing 110 in which a sound absorbing member 120 is placed. The sound absorbing member 120 may be made of any suitable material, such as a woven or non-woven fabric, acoustic foam such as melamine foam, fibreglass, cork, and so on.

(10) An optical medium 130 is placed over the sound absorbing member 120, which has a first set 140 of solid state lighting elements 142 placed along a first edge and a second set 140′ of solid state lighting elements 142′ placed along a second edge opposite the first edge of the optical medium 130. Any suitable solid state lighting element, e.g. light emitting diodes such as high-brightness LEDs or organic LEDs or electroluminescent elements may be used. In a preferred embodiment, the sets 140 and 140′ comprise strips of LEDs. In an embodiment, the sets 140 and 140′ are adhered, e.g. glued, to the optical medium 130. In an alternative embodiment, the sets 140 and 140′ are integrated in the optical medium 130. In yet another embodiment, the sets 140 and 140′ are fixated against the optical medium 130, e.g. using clips or the like. In yet another embodiment, the sets 140 and 140′ are fixated against the housing 110. It should be understood that the sets 140 and 140′ of solid state lighting elements 142 and 142′ may be placed at the opposite edges of the optical medium 130 in any suitable manner. It should furthermore be understood that the present invention is not limited to a sound absorbing lighting panel 100 comprising two sets of solid state lighting elements; any suitable number of sets on any number of sides, e.g. along all sides, of the sound absorbing lighting panel 100 or optical medium 130, may be used.

(11) In accordance with the present invention, the sound absorbing lighting panel 100 further comprises a translucent sheet 150 having a higher translucency in a central area of the sound absorbing lighting panel 100 than at the edges of the sound absorbing lighting panel 100 where the solid state lighting elements 142 and 142′ are located. This is indicated in FIGS. 1 and 2 by the grayscale gradient in the translucent sheet 150, in which a lighter tone indicates a higher translucency. In other words, the translucent sheet 150 has a translucency gradient that is increasing from an edge portion of the sound absorbing lighting panel 100 where the solid state lighting elements 142, 142′ are located to the centre of the sound absorbing lighting panel 100.

(12) The purpose of this translucency gradient is explained with the aid of FIG. 3, which gives a schematic representation of the light distribution 310 in the optical medium 130, the translucency 320 of the translucent sheet 350 and the light output intensity 330 of the sound absorbing lighting panel 100 as a function of the width profile W of the sound absorbing lighting panel 100, in which the edges of the profile correspond with the edges of the sound absorbing lighting panel 100 at which the solid state lighting elements 142, 142′ are located and the centre of the profile corresponds with the centre of the sound absorbing lighting panel 100.

(13) The light distribution profile 310 is the direct result of the solid state lighting elements 142, 142′ being placed at the edges of the sound absorbing lighting panel 100. Due to the fact that a fraction of the light emitted into the optical medium 130 does not internally reflects inside this member but is diffracted out of this member instead, the light intensity inside the optical medium 130 continually decreases from the edge of the sound absorbing lighting panel 100 towards its centre.

(14) Without any additional measures, this would result in a light output having the light distribution profile 310, i.e. a non-homogeneous light output profile in which the edges of the sound absorbing lighting panel 100 would appear brighter than its centre, which is aesthetically unappealing. This is compensated by the translucency gradient 320 in the translucent sheet 150, which ensures that less light can escape the optical medium 130 near the edges of the sound absorbing lighting panel 100 compared to the central region of this panel, such that the resulting light output profile 330 of the sound absorbing lighting panel 100 is homogeneous, i.e. of constant intensity over the width W of the sound absorbing lighting panel 100. Hence, by balancing the placement and output intensity of the solid state lighting elements 142, 142′ and the translucency of the translucent sheet 150, a homogeneous light output can be achieved for the sound absorbing lighting panel 100.

(15) In an embodiment, the optical medium 130 is an air-filled cavity delimited by the housing 110, in which case the translucent sheet 150 may be fitted to the surface of an extraction member (not shown) facing the optical medium 130 such that the optical medium 130 is located in between the extraction member and the sound absorbing member 120. Alternatively, the translucent sheet 150 may be fitted to the housing 110 or may be fitted in any other suitable manner. In this embodiment, the sound absorbing member 120 may further comprise a reflective surface facing the optical medium to reduce absorption of the emitted light by the sound absorbing member 120. Although an air-filled cavity is preferable, it should however be understood that any suitable optical medium 130, e.g a light guide, may be used instead.

(16) In an embodiment, the translucent sheet 150 may comprise a woven fabric such as a fibreglass weave or one or more non-woven sheets. The translucency gradient may be achieved in such a (non-)woven material by applying an opaque paint to the material and increasing the thickness of the paint towards the edges of the sound absorbing lighting panel 100 where the solid state lighting elements 142, 142′ are placed. Alternatively, in case of a woven material, the translucency gradient may also be achieved using a weaving technique in which the material has a more open weave towards the centre of the material when placed in the sound absorbing lighting panel 100.

(17) An alternative embodiment of the translucent sheet 150 is shown in FIG. 4. In this embodiment, the translucent sheet 150 comprises a pattern of perforations 152, which pattern has a higher perforation density in the centre of the sound absorbing lighting panel 100 compared to the edge regions of the sound absorbing lighting panel 100 where the solid state lighting elements 142 and 142′ are located to achieve the translucency gradient 320 in the translucent sheet 150.

(18) Yet another alternative embodiment of the translucent sheet 150 is shown in FIG. 5. In this embodiment, the translucent sheet 150 comprises a pattern of perforations 152 in which the diameter of the perforations 152 increases towards the centre of the sound absorbing lighting panel 100 to give the sound absorbing lighting panel 100 a more open structure towards its centre, thus achieving the desired gradient in the translucency of the translucent sheet 150. In the embodiments of FIG. 4 and FIG. 5, the translucent sheet 150 may be formed of any suitable material that may be perforated, such as a metal or plastic sheet.

(19) At this point, it is noted that the translucent sheet 150 should a surface area of which at least 3% consists of openings to allow sound waves to effectively travel through the translucent sheet 150 towards the sound absorbing member 120. The openings preferably should be distributed evenly over the surface of the translucent sheet 150 to ensure that the whole surface of the sound absorbing lighting panel 100 is capable of absorbing sound waves.

(20) It is also preferable that the housing 110 comprises reflective inner surfaces to avoid light escaping sideways from the sound absorbing lighting panel 100, thus maximizing the light efficiency of the sound absorbing lighting panel 100.

(21) It should be understood that several variations are possible to the embodiments shown in FIGS. 1 to 5 without departing from the teachings of the present invention. For instance, the sound absorbing lighting panel 100 may comprise any suitable arrangement of further optical elements, e.g. beam shaping elements, diffusers, light extraction coatings and so on.

(22) Also, although the sound absorbing lighting panel 100 preferably contains a first set 140 of solid state lighting elements 142 and a second set 140′ of solid state lighting elements 142′ at opposite edges of the optical medium 130, it should be understood that one of the sets 140 and 140′ may be omitted, thus yielding a sound absorbing lighting panel 100 comprising a single set of solid state lighting elements along a single edge of the optical medium 130. In this embodiment, the translucent sheet 150 has a translucency gradient that continuously increases from the edge of the optical medium 130 where the single set of solid state lighting elements are located towards the opposite edge of the optical medium 130.

(23) FIG. 6 schematically depicts an embodiment of a modular surface system 600 of the present invention, e.g. a suspended ceiling system. The modular surface system 600 comprises a support frame 610 into which a plurality of surface tiles 620 are suspended. At least some of the surface tiles 620 are sound absorbing lighting panels 100 according to one or more embodiments of the present invention. The support frame 610 may be attached to the surface in any suitable manner. As many different fixation methods are well-known per se, this will not be explained in further detail for the sake of brevity only.

(24) It should furthermore be understood that the tile size and shapes in FIG. 6 are shown by way of non-limiting example only. Any suitable tile size and shape may be chosen.

(25) At least some of the aforementioned embodiments of the present invention are designed to produce a uniform light distribution over the surface of the sound absorbing lighting panel 100. However, it should be understood that it is equally feasible to provide the translucent sheet 150 with a translucency distribution that generates a non-uniform light distribution, e.g. to highlight shapes such as characters or letters, logos, trademarks, images and so on.

(26) It should also be understood that multiple sheets of the translucent sheet 150 may be combined in order to achieve the desired translucency distribution at the luminous surface of the sound absorbing lighting panel 100.

(27) It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word “comprising” does not exclude the presence of elements or steps other than those listed in a claim. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several distinct elements. In the device claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.