A LIGHT MIXING CHAMBER AND A LUMINAIRE

Abstract

The present invention relates to a light mixing chamber (100). The light mixing chamber (100) comprising: a first light mixing chamber part (120) comprising a light exit window (122) and a first side wall (124) having a first groove (126); a second light mixing chamber part (140) comprising a bottom wall (142) and a second side wall (144) having a second groove (146); and an LED substrate (160) supporting a plurality of LEDs (162,164,166,168). The LED substrate (160) is arranged into the first (126) and second grooves (146), interconnecting the first and the second light mixing chamber parts (120,140) such that the light mixing chamber (100) is formed. The plurality of LEDs (162,164,166,168) of the LED substrate (160) is facing an inner cavity (180) of the light mixing chamber (100).

Claims

1. A light mixing chamber comprising: a first light mixing chamber part comprising a light exit window and a first side wall having a first inner wall portion and a first outer wall portion, spaced apart and together forming a first groove, a second light mixing chamber part comprising a bottom wall and a second side wall having a second inner wall portion and a second outer wall portion, spaced apart and together forming a second groove, an inner cavity, and an LED substrate having a front surface facing the inner cavity and a back surface facing away from the inner cavity, the front surface supporting a plurality of LEDs, wherein the LED substrate is arranged into the first and second grooves, interconnecting the first and the second light mixing chamber parts such that the light mixing chamber is formed, wherein the first inner wall portion of the first side wall is extending further away from the light exit window than the first outer wall portion of the first side wall and/or the second inner wall portion of the second side wall is extending further away from the bottom wall than the second outer wall portion of the second side wall, and wherein between 5% to 50% of the back surface of the LED substrate is covered by the first and second grooves.

2. The light mixing chamber according to claim 1, wherein the first inner wall portion of the first side wall comprises a light reflective inner surface facing the inner cavity of the light mixing chamber and/or wherein the second inner wall portion of the second side wall comprises a light reflective inner surface facing the inner cavity of the light mixing chamber.

3. The light mixing chamber according to claim 1, wherein the LED substrate comprises a plurality of fins arranged on the back surface of the LED substrate.

4. The light mixing chamber according to claim 1, wherein the plurality of LEDs have a light emitting surface which is arranged at a distance from the first inner wall portion of the first side wall and from the second inner wall portion of the second side wall.

5. The light mixing chamber according to claim 1, wherein the LED substrate is a flexible elongated substrate.

6. The light mixing chamber according to claim 1, wherein the first side wall extends along a circumference of the light exit window of the first light mixing chamber part and/or wherein the second side wall extends along a circumference of the bottom wall of the second light mixing chamber part.

7. The light mixing chamber according to claim 1, wherein the first groove extends along a circumference of the light mixing chamber and/or wherein the second groove extends along the circumference of the light mixing chamber.

8. The light mixing chamber according to claim 1, wherein the first and second grooves cover the front surface of the LED substrate such that substantially only the plurality of LEDs faces the inner cavity of the light mixing chamber.

9. The light mixing chamber according to claim 1, wherein the LED substrate extends along the circumference of the light mixing chamber.

10. The light mixing chamber according to claim 1, wherein the bottom wall comprises a light reflective inner surface facing the inner cavity of the light mixing chamber and/or the light exit window is light diffusive having a reflectance in the range from 30% to 80%.

11. The light mixing chamber according to claim 1, wherein the LED substrate comprises two or more LED substrate portions.

12. A luminaire comprising the light mixing chamber according to claim 1 and a driver for driving the plurality of LEDs.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiments of the invention. The figures should not be considered limiting the invention to the specific embodiment; instead they are used for explaining and understanding the invention.

[0027] FIG. 1 illustrates a cross-sectional side view of different parts of a light mixing chamber prior to assembling the different parts.

[0028] FIG. 2 illustrates a cross-sectional side view of a light mixing chamber, subsequent to assembling different parts.

[0029] FIG. 3 illustrates a perspective view of a light mixing chamber.

[0030] FIG. 4 shows a perspective view of a luminaire.

[0031] FIG. 5 shows a perspective view of parts of a luminaire.

[0032] As illustrated in the figures, the sizes of components are exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of embodiments of the present invention. Like reference numerals refer to like elements throughout.

DETAILED DESCRIPTION

[0033] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

[0034] FIG. 1 illustrates a cross-sectional side view of different parts of a light mixing chamber 100 prior to assembling the different parts for forming the light mixing chamber 100. The light mixing chamber 100 comprises a first light mixing chamber part 120 and a second light mixing chamber part 140. The first and the second light mixing chamber parts 120 and 140 may be manufactured by means of fused deposition modelling (FDM). The first and the second light mixing chamber parts 120 and 140 may be manufactured by any other means such as injection molding, compression molding, or vacuum forming. The first and the second light mixing chamber parts 120 and 140 may have different forms and sizes. For instance, the first and the second light mixing chamber parts 120 and 140 may have a circular, an oval, a rectangular, a hexagonal or a square shape. A dimension of the first and the second light mixing chamber parts 120 and 140 along X and Y axes, shown in FIG. 1, may be in a range of 3 to 300 mm. A dimension of the first and the second light mixing chamber parts 120 and 140 along an axis Z, shown in FIG. 1, may be in a range of 0.3 to 6 cm.

[0035] The first light mixing chamber part 120 comprises a light exit window 122. The light exit window 122 may be light diffusive. The light exit window 122 may be light diffusive for visible light having a reflectance in the range from 30% to 80%. The light exit window 122 may be formed of a polymer. The polymer may be translucent, preferably diffuse. The polymer may comprise light scattering material such TiO.sub.2, BaSO4, and/or Al.sub.2O.sub.3 particles. The second light mixing chamber part 140 comprises a bottom wall 142. The bottom wall 142 may comprise a light reflective inner surface facing an inner cavity 180 to be formed by connecting different parts of the light mixing chamber 100. For instance, the inner surface of the bottom wall 142 may be coated by a light reflective material. The bottom wall 142 may be made of white diffusive and high reflective material. The bottom wall 142 may comprise a light reflective material. The bottom wall 142 may e.g. comprise high TiO.sub.2 loaded plastics, or high reflective sheet material such as MCPET.

[0036] The first light mixing chamber part 120 comprises a first side wall 124 having a first groove 126. The second light mixing chamber part 140 comprises a second side wall 144 having a second groove 146. The first side wall 124 and the second side wall 144 may comprise a polymer e.g. PC, PET, PE, silicone. The first side wall 124 and the second side wall 144 may comprise particles e.g. light reflective particles, e.g. reflective Al and/or Ag flakes or light scattering particles e.g. BaSO.sub.4, Al.sub.2O.sub.3 and/or TiO.sub.2. A dimension of the first side wall 124 and the second side wall 144 along the Z axis, shown in FIG. 1, may preferably be in a range of 0.3 to 6 cm. The dimension of the first side wall 124 and the second side wall 144 along the Z axis, shown in FIG. 1, may more preferably be in a range of 0.4 to 4 cm. The dimension of the first side wall 124 and the second side wall 144 along the Z axis, shown in FIG. 1, may most preferably be in a range of 0.5 to 3 cm.

[0037] The first side wall 124 may comprise a first inner wall portion 123 and a second outer wall portion 125. The second outer wall portion 125 may be a continuous wall or a non-continuous wall. The first inner wall portion 123 and the first outer wall portion 125 of the first side wall 124 are spaced apart from each other. A distance between the first inner wall portion 123 and the first outer wall portion 125 of the first side wall 124 may be in a range of 0.5 to 3 mm. The first inner wall portion 123 and the first outer wall portion 125 of the first side wall 124 together form the first groove 126.

[0038] The second side wall 144 may comprise a second inner wall portion 143 and a second outer wall portion 145. The second outer wall portion 145 may be a continuous wall or a non-continuous wall. The second inner wall portion 143 and the second outer wall portion 145 of the second side wall 144 are spaced apart from each other. A distance between the second inner wall portion 143 and the second outer wall portion 145 of the second side wall 144 may be in a range of 0.5 to 3 mm. The second inner wall portion 143 and the second outer wall portion 145 of the second side wall 144 together form the second groove 146. The first inner wall portion 123 of the first side wall 124 may extend further away from the light exit window 122 than the first outer wall portion 125 of the first side wall 124. In other words, a length of the first inner wall portion 123 of the first side wall 124 along the Z axis, see FIG. 1, may be longer than a length of the first outer wall portion 125 of the first side wall 124 along the Z axis. The second inner wall portion 143 of the second side wall 144 may extend further away from the bottom wall 142 than the second outer wall portion 145 of the second side wall 144. In other words, a length of the second inner wall portion 143 of the second side wall 144 along the Z axis, see FIG. 1, may be longer than a length of the second outer wall portion 145 of the second side wall 144 along the Z axis. The first inner wall portion 123 of the first side wall 124 may comprises a light reflective inner surface facing an inner cavity 180 to be formed by connecting different parts of the light mixing chamber 100. For instance, the first inner wall portion 123 of the first side wall 124 may be coated by a light reflective material. The first inner wall portion 123 of the first side wall 124 may be formed of a light reflective inner surface. The second inner wall portion 143 of the second side wall 144 may comprises a light reflective inner surface facing an inner cavity 180 to be formed by connecting different parts of the light mixing chamber 100. For instance, the second inner wall portion 143 of the second side wall 144 may be coated by a light reflective material. The second inner wall portion 143 of the second side wall 144 may be formed of a light reflective inner surface.

[0039] The light mixing chamber 100 further comprises a LED substrate 160. The LED substrate 160 may be thermally conductive. The LED substrate 160 may comprise a metal. For instance, the LED substrate 160 may comprise Copper (Cu) and/or Aluminum (Al). The LED substrate 160 may be a flexible elongated substrate e.g. a flexible LED strip. The LED substrate 160 may comprise two or more LED substrate portions. The LED substrate 160 supports a plurality of LEDs. The plurality of LEDs may preferably comprise at least 10 LEDs. The plurality of LEDs may more preferably comprise at least 15 LEDs. The plurality of LEDs may most preferably comprise at least 20 LEDs. Two LEDs 162 and 164 of the plurality of LEDs are shown in FIG. 1. FIG. 1 further shows that the plurality of LEDs 162 and 164 have a light emitting surface. The light emitting surface of the plurality of LEDs 162 and 164 is arranged at a distance from the first inner wall portion 123 of the first side wall 124 and from the second inner wall portion 143 of the second side wall 144. The plurality of LEDs may comprise various types of LEDs such organic LEDs (OLED). The plurality of LEDs may comprise white LEDs e.g. cool white (CW) or warm white (WW). The plurality of LEDs may comprise colored LEDs e.g. red, green, or blue LEDs. The plurality of LEDs may comprise any of or any combination of white and colored LEDs. The LED substrate may further comprise a plurality of fins arranged on a back surface, the surface facing away from the cavity 180, of the LED substrate 160. The fins may be optionally be arranged along the Z axis. In the case that the first outer wall portion 125 of the first side wall 124 and the second outer wall portion 145 of the second side wall 144 are non-continuous, the first and second outer wall portions 125 and 145 may be non-continuous at the positions of the fins. An inner surface of the LED substrate may preferably be highly reflective.

[0040] FIG. 2 illustrates a cross-sectional side view of the light mixing chamber 100, subsequent to assembling different parts. Hence, in FIG. 2 the different parts of the light mixing chamber 100 are assembled forming the light mixing chamber 100. The LED substrate 160 is arranged into the respective first 126 and second grooves 146 of the first and the second light mixing chamber parts 120 and 140. Between 5% to 50% of a back surface of the LED substrate 160, the surface facing away from the inner cavity 180, may be covered by the first 126 and second grooves 146. FIG. 2 shows that the first 126 and second grooves 146 cover a front surface, the surface facing the cavity 180, of the LED substrate 160. FIG. 2 further shows that substantially only the plurality of LEDs 162 and 164 faces the inner cavity 180 of the light mixing chamber 100. The LED substrate 160 interconnects the first and the second light mixing chamber parts 120,140, in other words, the LED substrate 160 connects the first and second light mixing chamber parts 120 and 140, respectively, to one another, and forms the light mixing chamber 100. The light mixing chamber 100 has an inner cavity 180. The plurality of LEDs 162 and 164 of the LED-substrate 160 face the inner cavity 180 of the light mixing chamber 100. A height of the light mixing chamber along the Z axis shown by H in FIG. 2 may be in a range of 10 to 100 mm.

[0041] FIG. 3 shows a perspective view of the light mixing chamber 100. As shown in FIG. 3, the light mixing chamber 100 may have a circular shape. FIG. 3 is illustrated such that plurality of LEDs facing an inner cavity 180 of the light mixing chamber 100 are visible. The first side wall 124 may extend along a circumference of the light exit window 122 of the first light mixing chamber part 120. The second side wall 144 may extend along a circumference of the bottom wall 142 of the second light mixing chamber part 140. The first groove 126 may extend along a circumference of the light mixing chamber 100. The second groove 146 may extend along the circumference of the light mixing chamber 100. The LED substrate 160 may extend along the circumference of the light mixing chamber 100.

[0042] FIG. 4 shows a perspective view of a light exit window of a luminaire 200. The luminaire 200 comprises the light mixing chamber 100 and a connection 210 to a driver. The connection 210 is configured to connect the plurality of LEDs of the light mixing chamber 100 to a driver. The connection 210 in FIG. 4 is illustrated in the form of a wire. The connection 210 provides electricity to the plurality of LEDs of the light mixing chamber 100. The driver may be any conventional and commercially available driver. FIG. 4 further shows a plurality of fins 172, 174, 176, and 178 arranged on a back surface, the surface facing away from the inner cavity 180, of the LED substrate 160.

[0043] FIG. 5 shows a perspective view of parts of the luminaire 200 shown in FIG. 4. Especially, the second light mixing chamber part 140, the LED substrate 160 and the connection 210 parts of the luminaire 200 are illustrated. FIG. 5 further shows a plurality of fins 172, 174, 176, and 178 arranged on a back surface, the surface facing away from the inner cavity 180, of the LED substrate 160. The LED substrate 160 supports a plurality of LEDs, such as LEDs 162, 164, 166, and 168. In FIG. 5 the luminaire 200 is illustrated in an “open state” i.e. the first light mixing chamber part 120 is disassembled form the light mixing chamber 100. As illustrated, by disconnecting the first light mixing chamber part 120, the LED substrate 160 is accessible. The LED substrate 160 may be hence replaced, if needed.

[0044] The luminaire 200 may be installed on a ceiling of a room such that the bottom wall 142 may face the ceiling and the light exit window 122 may face the room.

[0045] Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage.