Customizable 3D-printed lighting device

Abstract

The invention provides lighting device (1000) configured to provide a beam of lighting device light (1001), the lighting device (1000) comprising: (a) a light transmissive window (100) having a first window side (101) and a second window side (102); (b) a reflector (200) comprising a reflector cavity (210), the reflector cavity (210) comprising a first reflector cavity side (201), a reflector cavity exit side (202), a reflector cavity wall (205) bridging said first reflector cavity side (201) and said reflector cavity exit side (202); wherein the reflector cavity wall (205) comprises a light reflective material (206), wherein the recavity wall (205) comprises a 3D-printed cavity wall (1205); wherein at least part of the first window side (101) is configured as reflector cavity exit window (220) at the reflector cavity exit side (202); (c) a light source (10) configured at the first reflector cavity side (201) and configured to provide light source light (11) within said reflector cavity (210); and (d) a beam modifying element (300) configured at the first window side (201) within the reflector cavity (210), wherein the beam modifying element (300) comprises a 3D-printed beam modifying element (1300).

Claims

1. A method of producing a lighting device, the method comprising: providing a light transmissive window having a first window side and a second window side; 3D printing a reflector cavity comprising a light reflective material to the first window side, to provide a reflector cavity, the reflector cavity comprising a first reflector cavity side, a reflector cavity exit side a reflector cavity wall bridging said first reflector cavity side and said reflector cavity exit side; and 3D printing a beam modifying element at the first window side, to provide said beam modifying element within the reflector cavity; and providing a light source at the first reflector cavity side, the light source being configured to provide light source light, within said reflector cavity.

2. The method according to claim 1, further comprising fused deposition modeling 3D printing the reflector cavity wall and fused deposition modeling 3D printing the beam modifying element.

3. The method according to claim 1, wherein the first window side is substantially planar.

4. The method according to claim 1, wherein the first window is a non-3D printed first window, wherein the first window comprises a window material, wherein the reflector cavity wall comprises a reflector cavity wall material, and wherein the window material and the reflector cavity wall material comprise the same polymeric material.

5. The method according to claim 1, further comprising the steps of defining one or more lighting parameters for a space and producing the lighting device in dependence of the one or more lighting parameters.

6. The method according to claim 1, wherein the beam modifying element comprises a beam shaping element.

7. The method according to claim 1, wherein the beam modifying element comprises a glare reduction element.

8. The method according to claim 1, wherein the beam modifying element comprises a luminescent material configured to convert at least part of the light source light into luminescent material light.

9. The method according to claim 1, wherein the light source comprises a solid state light source.

10. The method according to claim 1, wherein the reflector cavity has equal to or less than one symmetry plane.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

(2) FIG. 1 schematically depicts an embodiment of the lighting device as described herein;

(3) FIGS. 2a-2d schematically depict some variants;

(4) FIGS. 3a-3c schematically depict some further aspects;

(5) FIGS. 4a-5d schematically depict some embodiments and light distributions obtainable therewith; and

(6) FIG. 6 schematically depicts an embodiment of a 3D printer that may be used in the herein described method for producing the lighting device.

(7) The schematic drawings are not necessarily to scale.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(8) 3D printing of e.g. downlights offers unique design and customization opportunities. One may design almost free-form intensity profiles and create a look and feel with fits to the unique architecture of a new or refurbished building. It also offers opportunities for retrofitting existing lighting systems (i.e. systems based on TL or other conventional light source). This means that is possible to reproduce the intensity profile of a conventional luminaire exactly by a 3D printed lighting system. This invention describes a process to fabricate tailor-made lighting devices, such as downlights. The described technology and embodiments are not limited to downlights but can be applied to e.g. office lighting and high-bay lighting as well. The invention focuses on Fused Deposition Modelling (FDM) which is also called Fused Filament Fabrication (FFF).

(9) FIG. 1 schematically depicts an embodiment of a lighting device 1000 configured to provide a beam of lighting device light 1001. The lighting device 1000 comprises a light transmissive window 100, a reflector 200, a light source 10, and a beam modifying element 300.

(10) The light transmissive window 100 has a first window side 101 and a second window side 102.

(11) The reflector 200 comprises a reflector cavity 210. The reflector cavity 210 comprises a first reflector cavity side 201, a reflector cavity exit side 202, a reflector cavity wall 205 bridging said first reflector cavity side 201 and said reflector cavity exit side 202. The reflector cavity wall 205 comprises a light reflective material 206. The reflector cavity wall 205 comprises a 3D-printed cavity wall 1205. Further, at least part of the first window side 101 is configured as reflector cavity exit window 220 at the reflector cavity exit side 202.

(12) The light source 10 is configured at the first reflector cavity side 201 and configured to provide light source light 11 within said reflector cavity 210. In this way a beam may be shaped with the reflector 200. The beam modifying element 300 is configured at the first window side 101 within the reflector cavity 210. Further, the beam modifying element 300 comprises a 3D-printed beam modifying element 1300.

(13) Reference 17 indicates a support for the light source 10, such as a PCB. Reference h indicates the height of the window 100, such as 1-5 mm.

(14) Here, first reflector cavity side 201 and said reflector cavity exit side 202 are indicated with dashed lines, as these side are in the schematically depicted embodiment(s) closed with the support 17 and window 200, respectively. In the schematically depicted embodiment, one side of the support 17 and the first reflector cavity side 201 substantially coincide in the drawing (over the length of the first reflector cavity side 201); the second reflector cavity side 202 and the first window side 101 substantially coincide in the drawing (over the length of the second reflector cavity side 202).

(15) Here, the reflector cavity 210 may substantially be symmetric. Dependent upon the configuration of the beam modifying element 300, the beam of lighting device light 1001 may be symmetric or asymmetric.

(16) FIGS. 2a-2b schematically depict two non-limiting variants of the beam modifying element 300, with in FIG. 3a a beam modifying element 300 substantially consisting of a single piece (such as a single layer), and in FIG. 3b a beam modifying element 300 substantially consisting of a plurality of pieces, such as dots or lines. In both embodiments, the beam modifying element 300 is configured at the first window side. The beam modifying element 300 occupies a first area A1. The remaining area is indicated with reference A2. In FIG. 2a, the area A1 is about 30% of the total area A1+A2, i.e. the total area of the first window side within the cavity. FIG. 2a may e.g. show a glare reduction element 303 as beam modifying element 300. FIG. 2b may e.g. schematically depict a beam shaping element as beam modifying element 300. Note that in fact in general each element configured within the beam will have a beam modifying effect. The height of the beam modifying element 300 is indicated with reference h1, and may especially be in the range of at least 100 m, such as in the range of 200 m-10 mm, such as 500 m-5 mm.

(17) FIG. 2c schematically depicts an embodiment of the beam modifying element 300 wherein the beam modifying element 300 is configured non-symmetrical. Further, by way of example a second beam shaping element 401 is depicted, here a plurality of second beam shaping elements 401, such as a Fresnel lens. This second beam shaping element 401 is not limited to the specific embodiment of the non-symmetrically configured beam modifying element 300. The non-symmetrically configured beam modifying element 300 is not necessarily combined with the second beam shaping element; also other embodiments may include such second beam shaping element. Further, here by way of example the second beam shaping element is configured at the second side of the window, i.e. the downstream side. Note that the second beam shaping element 401 may optionally also configured at the first window side 101, especially when the second beam shaping element 401 includes micro-optical structures having heights h2 of at maximum 50 m, and widths 2 of at maximum 50 m.

(18) FIG. 2d schematically depicts a luminescent material 310 comprising beam modifying element 300. At least part of the light source light 11 may be converted into luminescent material light 311.

(19) The following features may e.g. be applied:

(20) (1) A flat, rigid transparent optical plate (PMMA, polycarbonate, glass) of arbitrary shape. The plate is optionally provided with optical (micro) structures and/or textures on one or both sides of the plate. A typical thickness range of the plate is 1-5 mm. 3D printing (FDM) may give rise to artefacts not present in conventional products. A light texture present on the front plate prevents direct view in the reflector;

(21) (2) At least one hollow structure (white, diffuse material) is 3D printed on one side of the optical plate, mentioned in (1). The hollow structure has an exit surface and an entrance surface characterized by a closed curve r.sub.1() and r.sub.2() respectively. The 3D hollow structure is formed by a straight wall (height h above the optical plate) connecting the two closed curves r.sub.1() and r.sub.2(). Both curves can e.g. be described e.g. by a superellipse (see below) or by the superformula. The complete reflector can be characterized by r.sub.1(), r.sub.2() and h. The center of r.sub.1() may also be shifted w.r.t. the center of r.sub.2(). Even more design freedom is created when an extra closed curve r.sub.3() is introduced (FIG. 3c).

(22) (3) An optical structure is printed on part of the transparent optical plate, preferably on the same side where the white, hollow structure is printed. The printed structure(s) are located within the contour given by the function r.sub.1(). The printed structures can be of a white, diffuse material or a transparent polymeric material (PET, PC, PMMA);

(23) (4) A single solid state light source, especially an LED (e.g. Chip On Board; COB) or cluster of LEDs is placed at the entrance of the hollow structure.

(24) FIG. 3a schematically depicts an embodiment. Reference 1030 indicates a housing substantially enclosing the light source 10 and the reflector 200. The first side 201 of the reflector cavity 210 of the reflector 200 can be described with r2(). The second side 202 of the reflector cavity 210 can be described with r1(). FIG. 3a shows a cross-sectional view of the lighting device 1000. The height, defined as the distance between the light source 10 (more especially its exit window) and the exit window of the reflector 200, i.e. the second side 202, is indicated with reference h3.

(25) FIG. 3b schematically depicts a top view of an embodiment of the lighting device.

(26) FIG. 3c schematically depicts yet a further embodiment of the lighting device 1000, now with an extra feature: an extra closed curve indicated and described with r3().

(27) Beam shaping can be done when a LED (cluster) is placed in a tapered enclosure defined by an entrance area and an exit area. The enclosure is especially made from a white, highly reflecting material (matte or high gloss finish). The cut-off is determined by the angle as indicated in FIGS. 3a and 3c. The cut off angle may vary as a function of . The sharpest cut-off is created when the entrance surface area is small compared to the exit area. By playing with height (h31 and h32) and the functions r.sub.1(), r.sub.2() . . . r.sub.n(), an optimized beam can be defined fulfilling all glare regulations (e.g. Unified Glare Rating; UGR). In addition to creating a cut off in all directions, the beam shape could also be fine-tuned (especially at intensities around =0 deg.). This can be done by printing a suitable structure on part of the optical plate. This print can have an arbitrary shaped footprint (which can also be defined by a function r()). The beam shaping structure can be made of white, diffuse material (similar to the reflector) or a clear material (e.g. PC or PET).

(28) It appears that a high gloss, white reflector material gives the sharpest cut off and the lowest glare.

(29) The so-called superellipse may be described parametrically by

(30) $x=A{.Math.\cos \left(t\right).Math.}^{2/n}*\left[\frac{-\cos \left(t\right)}{.Math.\cos \left(t\right).Math.}\right]$$y=B{.Math.\sin \left(t\right).Math.}^{2/n}*\left[\frac{-\sin \left(t\right)}{.Math.\sin \left(t\right).Math.}\right]$$\mathrm{The}\mathrm{radius}r\mathrm{is}\mathrm{therefore}$$r\left(t\right)=\sqrt{x^2+y^2}$$0<t<2$

(31) FIGS. 4a-4d schematically depict a variant (FIGS. 4a-4c) and the light distribution obtained therewith. FIG. 4a is a front view, FIG. 4b is a side view, with at the bottom a light source, such as a COB (chip on board), and FIG. 4c schematically depicts a front plate having a 3D-printed beam modifying element which here comprises a plurality of white lines on the inside (i.e. directed towards the light source). The light distribution, with reduced glare, is shown in FIG. 4d.

(32) In FIGS. 4a-4c a lighting device is defined using the following features:

(33) (1) r1() is defined by a superellipse (see appendix). Parameters: n=5, A=B=60 mm

(34) (2) r2() is a circle with a radius of 7.5 mm

(35) (3) h=60 mm

(36) (4) A Luxeon COB 1203 (Lumileds) is used, which has a light emitting surface of 9 mm diameter (flux=1200 lm)

(37) (5) Texture is applied on the outside of the optical front plate (PMMA). The texture scatters light according to a Gaussian light distribution (=5 deg.)

(38) (6) The square beam shaping structure measures 35 mm35 mm and consists of printed, white stripes on the inside of the optical plate. The stripes have a width of 0.5 mm and a height of 1 mm. The stripes have a pitch which is not constant over the area. The material used is a TiO.sub.2 pigment filled PMMA.

(39) An intensity profile I(,) was calculated using the parameters defined above. The two intensity profiles in FIG. 4d correspond to the intensity profile in the x-z plane (curve a) and y-z plane (curve b) respectively. A desired delta shaped beam is obtained, creating a high illumination uniformity. The UGR value was 22.1 for this particular flux and exit area.

(40) FIGS. 5a-5d schematically depict a variant (FIGS. 5a-5c) and the light distribution obtained therewith. FIG. 5a is a side view, with at the top a light source, such as a COB, FIG. 5b is a front view, and FIG. 5d schematically depicts a front plate or window in cross-sectionhaving lenticular structures 3D printed on the inside of the window (i.e. directed towards the light source). The width of the lenticular structures is 1 mm, the curvature (1/R)=2, and the height is 0.2 mm. The lenticular structures are elongated in the y-direction. The light distribution, with reduced glare, is shown in FIG. 5d.

(41) In FIGS. 5a-5c a lighting system is defined using the following parameters:

(42) (1) r1() is defined as a superellipse (see appendix). Parameters: n=5, A=B=60 mm

(43) (2) r2() is a circle with a radius of 7.5 mm

(44) (3) h=60 mm

(45) (4) A Luxeon COB 1203 (Lumileds) is used having a light emitting surface of 9 mm diameter (flux=1200 lm)

(46) (5) Texture is applied on the outside of the optical front plate (PMMA). The texture scatters light according to a Gaussian light distribution (=5 deg.)

(47) (6) The square beam shaping structure measures 30 mm120 mm and consists of printed clear material (PMMA). The structure of the print is explained in FIGS. 5a-5c.

(48) An intensity profile I(,) was calculated using the parameters defined above. The two-lobbed larger curve and the smaller distorted-circular curve in FIG. 5d are the intensity profiles corresponding to the intensity profile in the x-z plane (curve a) and y-z plane (curve b) respectively. Printed patterns of a clear material will lead to highly efficient systems.

(49) FIG. 6 schematically depict some aspects of the 3D printer. Reference 500 indicates a 3D printer. Reference 530 indicates the functional unit configured to 3D print, especially FDM 3D printing; this reference may also indicate the 3D printing stage unit. Here, only the printer head for providing 3D printed material, such as a FDM 3D printer head is schematically depicted. Reference 501 indicates the printer head. The 3D printer of the present invention may especially include a plurality of printer heads, though other embodiments are also possible. Reference 502 indicates a printer nozzle. The 3D printer of the present invention may especially include a plurality of printer nozzles, though other embodiments are also possible. Reference 320 indicates a filament of printable 3D printable material (such as indicated above). For the sake of clarity, not all features of the 3D printer have been depicted, only those that are of especial relevance for the present invention. The 3D printer 500 is configured to generate a 3D item 10 by depositing on a receiver item 550 a plurality of filaments 320 wherein each filament 20 comprises 3D printable material, such as having a melting point T.sub.m. The 3D printer 500 is configured to heat the filament material upstream of the printer nozzle 502. This may e.g. be done with a device comprising one or more of an extrusion and/or heating function. Such device is indicated with reference 573, and is arranged upstream from the printer nozzle 502 (i.e. in time before the filament material leaves the printer nozzle 502). Reference 572 indicates a spool with material, especially in the form of a wire. The 3D printer 500 transforms this in a filament or fiber 320. Arranging filament by filament and filament on filament, an intermediate 3D item 110 may be formed.

(50) The term substantially herein, such as in substantially consists, will be understood by the person skilled in the art. The term substantially may also include embodiments with entirely, completely, all, etc. Hence, in embodiments the adjective substantially may also be removed. Where applicable, the term substantially may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%. The term comprise includes also embodiments wherein the term comprises means consists of. The term and/or especially relates to one or more of the items mentioned before and after and/or. For instance, a phrase item 1 and/or item 2 and similar phrases may relate to one or more of item 1 and item 2. The term comprising may in an embodiment refer to consisting of but may in another embodiment also refer to containing at least the defined species and optionally one or more other species.

(51) Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

(52) The devices herein are amongst others described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation or devices in operation.

(53) 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. Use of the verb to comprise and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article a or an preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means may 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.

(54) The invention further applies to a device comprising one or more of the characterizing features described in the description and/or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterizing features described in the description and/or shown in the attached drawings.

(55) The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.